DE2114253A1 - Device for television signal transmission - Google Patents

Description

Device for Feroeeh signal transmission

Biβ invention relates to a device for transmission ▼ on TV. signal en c

The invention has for its object to multiply audio signals and with a television signal two sets of picture and Speech signals transmitted by alternately in every other Horizontal scanning period sent out two sets of video signals will.

The above and other objects, features, and advantages of the invention will be apparent from the detailed description that follows in connection with the drawings given. Point in the drawings

Figure 1 is a block diagram to illustrate the principle a television signal transmission device embodying the invention}

figure

109849/1004

21U253

Figure 2 is a circuit diagram of the essential parts of the erfindungsgeaä £ en Device

Figure 3 shows a representation of pulse shapes (A, B, C, D and S) to explain the device;

Figures 4, 5 and 6 also represent positions of Impulse forms (F, G, E and J Ise or K, L, M and N as well as F, Q and ü) to explain the device

FIG. 7 shows a circuit diagram for a specific part of the Device; and

Fi gas 3 a bar position tone voltage gradients for Explanation of the devices.

The principle of the invention should first be clarified in accordance with FIG. 1. Bai the Yervielfaehuag of video signals is called sin signal on AEbt a string as Hauptk anal signal and a signal on the other side as accommodation anal signal. In Figure 1, the reference number 1 denotes a sound carrier modulator, the reference number 2 © in ^ nträgergenerater, the reference number 3 a modulator for modulating over subcarriers through audio signals of the subchannel ε and the reference number 4 @iR audio subcarrier generator, this part © being the arrangement are all known and should not be explained in more detail «The reference numbers 5 and 6 denote ¥ ide © signal modulators, the construction and function of which is the same as in comparable, today standard devices, whereby the video signals of the main and sub-channels to the modulator 5 or 6 are supplied. The reference numeral 7 is a circuit for holding modulated signals of the picture carriers by switching between the signals of the modulators 3 and 6 in each horizontal scanning period (in the US and Japanese systems about 6j.5 microseconds) denoted by the reference numeral θ a picture carrier generator, With the Becugs number 9 a synchronous generator, with the Becugs number 10 a transmitting device for the transmission of a GeM see ε of audio and video carriers and with the reference number 11 a transmitting antenna. This transmission system with components 1 to 11 is the same with the exception of the video signal

modulator

109849/1004

_ 3- 21U253

modulator 6 and the circuit 7 the usual transmission system of a television broadcasting system, in which the audio signals are multiplied. In addition, the video signal modulators 5 and 6 are similar in their structure and mode of operation entirely, while the only difference is in the signals processed. The circuit 7 will therefore mainly be explained in the following.

A practical embodiment of the circuit 7 in FIG. 1 is shown in FIG. Reference number 12 is here denotes a bistable multivibrator, with the reference number 13 a Coupling capacitor, each with the reference numerals 14 and 15, a resistor for applying a base bias to a transistor 16, with the reference number 17 a collector resistance for the transistor 16 and with the reference number 18 an emitter resistance for this Transistor. The resistors 17 and 18 have the same resistance swert »The bistable multivibrator 12 is triggered by a horizontally synchronous signal and alternates in each period of the Horizontal scanning between passage and blocking. How on As will be described below, the bistable multivibrator 12 is supplied with ordinary horizontal synchronizing signals, with the exception of the vertical blanking periods. Tertikai synchronizing signals, horizontal synchronizing signals that are equal to 3H (IH one sampling period) following the tertiary sync signals appear, and horizontal sync signals from t. to t _Q are in

4 ο

the vertical blanking periods are inserted and therefore do not need to be fed to the bistable multivibrator 12. However, horizontal synchronizing signals are fed to the bistable multivibrator 12, beginning with the synchronizing signals S_ ₂ or S ¹ ″, in order to stabilize the actuation of the multivibrator 12 from time t ″.

The operation during a vertical deflection period will first be explained. The output of the synchronizing signal generator 9 is via the coupling capacitor 45 of FIG fed to the base of transistor 48. Reference numerals 46 and denote resistors for applying a bias voltage to the base of transistor 48, which acts as an A amplifier. - As an example

109849/1004

21U253

be the case of an output pulse shape of the synchronous signal generator 9 viewed with positive polarity, as illustrated in Figure 3 at (A). Resistor 49 in FIG. 2 acts it is a working resistance and its resistance value is higher than that of the emitter resistor 50 · A "synchronous signal with reversed phase is passed through the base of a transistor 54 A capacitor 51 is supplied. The resistors 52 and 53 are used to bias transistor 54 'so that it operates in Α mode. Numeral 55 denotes a working resistance for the Transistor 54 »while reference numeral 56 is an emitter resistor for the. Transistor denotes · An amplified signal produced with the Output of the synchronizing signal generator 9 is in phase appears at the collector of transistor 54 (see C in Figure j). This sync signal triggers the bistable multivibrator 12 via the capacitor 57 · The rise time of an output pulse is general β of the bistable multivibrator compared to the trigger pulse delayed by At, but as shown in Figure 3, it prepares no difficulty in making the time At smaller than the span of S microseconds of the horizontal synchronizing signal. The output voltage curve of the bistable multivibrator 12 is shown at D in FIG. This output is via the capacitor 13 fed to transistor 16. Resistors 14 and 15 are inserted for the purpose of giving transistor 16 a base bias granted. With the reference numerals 17 and 18 are the collector and denotes the emitter resistance of the transistor 18, both of which have the same resistance value. Capacitors 19 and 20 are used to transmit the output pulse shapes of the collector and emitters of transistors 24 and 33 »with resistors 26 and 35 connected in parallel with resistors 18 and 17, respectively are. Thus, the same values are set for the capacitor 19 and the resistor 26 as for the capacitor or the resistor 35 "appears on the collector and emitter of transistor 16 waveforms of equal amplitude and opposite phase, as shown in Figure 3 by (E) and (D) is illustrated.

Sound the video si gnaliiodulator 5 will be the basis of the

Transistor

1 09849 / 100A

21H253

On the other hand, transistor 24 through the capacitor 21 is supplied with video signals of the main channel. The reference numerals 22 and 23 denote resistors for applying a bias voltage to the base of the transistor 24, the reference numeral 25 denotes a collector resistor of the transistor 24 and the reference numerals 28 and 29 denote load resistances of the transistor 24. The reference numeral 26 denotes an emitter resistance of the transistor 24 , to which the voltage curve (D) of FIG. 3 is fed via the capacitor 20. If the values of the resistors 22 and 23 are determined accordingly, a blocking state begins, as can be seen from the voltage curve S, or in other words, the emitter voltage of the transistor 24 becomes positive with respect to the base voltage after every second one A time At has elapsed, namely the positive periods including that from t _Q + At to t_ + At, from t ^ + Afc to t ₁₂ + At and so on, so that there is then no output of the video signal modulator at the collector of transistor 24 is produced. During the periods from t _q + At to t ,, + At, from t._ + At to t ,, + At and so on, in which the output in the voltage curve B is KuIl, the transistor 24 works in A mode and the output of the video signal modulator 5 appears after amplification at the collector of the transistor 24. Reference numerals 31 and 32 denote resistors to apply a bias voltage to the base of transistor 33, and reference numeral 34 denotes a collector resistor for transistor 33 which, like two resistors 29 and 37, represents a load of transistor 33. The reference number 35 denotes an emitter resistor of the transistor 33, to which a voltage with the curve shown in FIG. 3 at (e) is fed via the capacitor 19. The reference numeral 35 ″ denotes a resistor for applying a bias voltage to the emitter so that the transistor 33 remains blocked under normal conditions by keeping the emitter potential of the transistor 33 at a value higher than its base potential. If the bias voltage between the base and the emitter of the transistor 33 is fixed in a suitable manner

placed

109849/1004

placed, the transistor 33 remains in the blocking state and appears on its collector during the potash voltage periods in the voltage curve (E) no output d «a Yideo signal modulator 6. During the negative periods of the voltage curve (E)» namely during the periods from t _Q + At to t _g + At, t.,., + At Ms t. "+ At and so on, the transistor 53 conducts" ^since "an emitter becomes negative with respect to its base, with the result that it is in! mode works and the output of the video signal modulator 6 amplified. If the outputs of the transistors 24 and 33 after the KL are transmitted by means of the resistors 28, 29 and 39, a signal like the one shown in FIG. 4 at (H), which occurs in each period de? Horizontal scanning includes the output of the video signal modulator 5 shown in FIG. 4 b®i (W) and the output of the Yidso signal modulator 6 W shown at (G)

of the transistor 41 a phase inversion and the resulting signal of the same polarity as at the outputs (F) and (G) appears at the collector of the transistor "41 In other words, a -agsaalgeasiseh (j) is obtained" that alternates every second Period of Horizontalabiaatunig contains the video signal (f) of the main channel and the video signal (G) of the üaterkanalg »If the signal (J) and an audio signal transmitted with a medium are received and separated in a suitable manner, the image and audio signals of the Main and sub-channels become deaoduliart to Sapfang.

Ms eolsher recipient is from inventor in Japan too ) ZUK patent ssgsmaldet been (ijmeldtingsixumer 45-30267 ^ ad

45-30266). Said the two signals (?) And (S) Sjneliroiisignale τοη have the same phase waä Aaplitud ", the signal mixture (J) also contains an ear signal vob glaislxor phase like the signals (F) and (G). At the above Saregtmgeia. it is about an explanation of a transferring thesis, in which the way of working in the form of a Yertikalaynchronsignal is excluded.

The working method in the sowing of a vertical »synchronous si ga & l β is now to be described. TV signals in the vicinity of a Yertikaisjac & ronsignala are in Figure 5 at (K) and (L)

shown

109849/1004

21U253

shown. A vertical control period lasts τοη t ₁ "to t ^ and in this period of time no video signal components occur, while the outputs of the video signal modulators 5 and 6 are the same synchronization and equalization pulses as shown in FIG. 5 at (K) and As a result, the signals τοη (H) and (j) of FIG. 4 which appear between t 1 and t 1 and which represent a mixture of the outputs of the video signal modulators 5 and 6 contain no video signals, and the voltage curve (J) is quite similar and in phase with the output voltage curve of the video signal modulator 5 or 6, the only difference being in the amplitude. This results in the fact that the output voltage curve of the bistable multiribrator 12 in FIG the combined outputs of the video signal modulators 5 and 6 are in phase opposition, since the inputs and outputs of the transistors 24 and 35 by Än Changes in the conduction periods of the transistors 24 and 33 are not influenced. If a vertical synchronizing signal begins in (K) in FIG. 5 at time t ₂ », an output voltage curve appearing at the emitter of transistor 48 is integrated by resistor 58 and capacitor 59 and that shown in FIG. 5 at (II) appears across capacitor 59 Stress curve. This voltage profile is fed to the base of the transistor 63 via the coupling capacitance 60. The resistors 61 and 62 serve to apply a bias voltage to the base of the transistor 63, and if the resistance values of the resistors 61 and 62 and the voltage of the battery 71 are designed accordingly, the base with respect to the emitter becomes only during the period of t 'to t' positive, so that the transistor 63 conducts, and a voltage curve appears at its collector, as shown in (H). MLt is a working resistance for the collector and reference number 65 denotes a resistance sum application of a backward bias voltage to the emitter. The voltage curve (N) is fed to the base of the transistor 69 via the capacitor 66. Reference numerals 67 and 68 denote resistors for applying a base bias, and if the resistance

values

109849/1004

_Λ . 21U253

If the values of the resistors 67 and 68 are selected accordingly, the collector current of the transistor 69 can be blocked when the base voltage drops by AV. As a result, an output voltage curve like that shown in FIG. 6 at (p) appears at the collector of transistor 69. In other words, although when the collector current of the transistor 69 is saturated, a positive voltage is constantly applied to the base of the transistor 69, the collector current decreases because the base voltage drops from t '. The collector voltage then rises and at time t ", when transistor 69 is blocked, the collector voltage has increased to + B YoIt and remains at this level until time t". The collector current begins to flow again at time t "

. Ben and the collector voltage will drop accordingly. The collector current is saturated ^{at t 1.} The reference numeral 70 denotes a collector load resistance of the transistor 69 «. By differentiating the voltage profile (p) with the aid of the capacitor 72 and the resistor 73, a voltage profile is obtained as shown in FIG. 6 at (q). The voltage curve (Q) is given by the diode 74 shown in Figure 2, so that the monostable part ti vibrator is triggered by the pulse (H), and an output pulse is generated shortly after t'_ at t ₂ + At ' ₂ . If the time constant of the monostable multivibrator is selected accordingly, the duration of the output pulse can be lengthened so that it ^{lasts from t f} _ + At ¹ - to t ", as shown in FIG. 6 at (u). As shown in Figure 5

) occurs, the point in time t, - is before a horizontal sync signal (S o) of a field of an odd number and after a horizontal sync signal (S ¹ ″) of a field of an even number. The pulse shown in (U) in FIG. 6 is fed to the bitter of transistor 54 via capacitor 76. In this connection eti mentions that the transit gate 54 with a suitable presetting of the resistance values of the resistors 52 and 53 in such a way that the bitter potential is positive with respect to the base potential during the period from t ' ₂ + At to t_, during the same Period remains locked, which has the consequence that the output of the synchronous signal generator 9 the bistable multivibrator

109849/1004

12 is not supplied so that it is not triggered during the same period.

On the other hand, part of the output of the monostable multivibrator 75 is fed to the circuit 77 in FIG. 2, which circuit 77 comprises the components shown in FIG. The reference number 78 denotes a capacitor and the reference number 79 a resistor for differentiating the voltage profile (II) of FIG. 6, and a ^{positive pulse received at time t '"+ At 1} is used to trigger the monostable multivibrator 81 of FIG. 7. The differentiation of the voltage curve XT of FIG. 6 inevitably results in the generation of a negative pulse at time te, but the diode 80 prevents this negative pulse from being fed to the monostable multivibrator 81. that this is shorter than the time from t '+ At' to t,. Assuming that the output pulse has gone out at time t, in Figure 5, the pulse duration extends from t ' ₂ + At ¹ to t_, as shown in Fig. 8 (a phase delay between the trigger pulse and the starting point of the pulse of the monostable multivibrator 81 is neglected gt). The resulting pulse W is fed to the switching trän si stör 85 via the capacitor 82. If the resistance values of the resistors 83 and 84 are selected accordingly, the transistor 85 can be brought into the blocking state when a pulse of the waveform (W) is supplied. If the bistable multivibrator 12 consists of transistors, the required power can be supplied from the collector of the transistor 85. If, therefore, the bistable multivibrator 12 is supplied with current from the battery 86 via the transistor 85, no current is supplied to the bistable multivibrator 12 ^{during the period from t '+ At 1 to t, whereas current is supplied from time t} will. Since, however, the transit gate 54 sees during the period from t 1 to t 1. is in the blocking state, the bistable multivibrator 12 is not supplied with a trigger pulse and ■ an output remains Mull. This output is also cool during those periods in which no current is supplied, and consequently

109849 / 100A

no pulse is fed to the base of transistor 16 of FIG. 2 during the period Ton t ' ₂ + Ä & «fcis te. As a result, the base potential remains at a DC voltage level, which depends on the resistors 14 and 15, and the associated absence of Ton Impulsaa esi collector and emitter causes the emitter of the transit gate 24 to be in the state given for (D) in FIG. 3 before time tg maintained, so that the transistor 24 conducts and the image carrier controller 8 via the transistor 41 amplified »video signal® of the main channel are fed.

On the other hand, the slitter of transistor 55 remains in the same state as before time t _Q in the voltage curve (Ε) of FIG. 5 »and since transistor 53 remains blocked, video signals of the sub-channel are transmitted.

f touching Sa saatia lets aioh see that the

Transistors 24 and 25? which alternate between the cut-off and the on-state in each horizontal scanning period, during the period of t. until t · + At 'after the introduction of the & βτ vertical control period are triggered by compensating impulses and toothed pulses in a tertiary yaelrone signal and work differently than during a vertical scanning period. However, the transistor 24 conducts to ZAM time t '+ δϊ ¹ and the transistor 33 is disabled so that the Bildträgergensratsr 8 are supplied only video signals of the main channel "Ba during Periods of t. until t + a ± · either transistor 24 or transistor 23 conducts, and since the signals of the main and sub-channels are also subject to control by the same subsequent tone, a normal vertical sync signal and the outgoing compensation pulse are fed to the video carrier generator 8 .

Bit Triggeruag of the bistable multivibrator * 12 starts in the partial images τοκ of an odd number and of an even number at the tent points t _Q beaielmngoweise t ' _Q. Bern emitter of transistor 33 is therefore between the synchronizing signals S, and S - with a delay side At, as shown in (B) and (E) of Figure 3, a positive pulse supplied, whereby the transistor 24 is blocked, so that the transistor 53 b * i supply of an aggressive impulse · «xu his baitte? in the managerial

gtaad

10 9849/1004

21U253

stand passes. At the moment t _g + At, the transit gate 24 conducts and the transistor 33 is blocked * Repeat similar gates at this point in time. The result is that a subchannel signal is fed to the image carrier generator 8 as well as the first synchronizing _{signal S 1} and S ₂ , and a main channel signal _{between S 2 and S 1.} Then repeat similar processes. In the even fields of the image carrier generator is β between S ¹ and S * a main channel video signal supplied while it between S ¹ - ^a main channel signal is supplied, and S '. ₂ As. from the above, the video carrier generator 8 is supplied with a video signal of the sub-channel during the period tob first tob second horizontal synchronization signal following a vertical blanking period, whereas the video carrier generator 8 is supplied with a signal of the main channel during the period between the second and third horizontal synchronization signal will. Danaoh alternates operations so that the main and sub-channel signals can be transmitted simultaneously over a single series of television waves. The syncronous signals include those which are common to the main and subchannels, and even if the main and subchannels are exchanged "which should be mixed with one another, this cannot lead to a disturbance of the synchronous signals.

Claims

109849/1004

Claims (1)

- 12 -P patent claims Apparatus for television signal transmission, characterized by the alternating mixing and transmission of two sets of video signals by means of a single image carrier shaft. 2. Apparatus for television signal transmission according to claim 1, characterized in that two sets of audio signals can be transmitted at the same time. 3. Apparatus for television signal transmission according to Claim 1, characterized in that the two sets of video signals alternate are transmittable in every other horizontal scanning period. 4. Apparatus for television signal transmission according to claim 1, characterized in that a bistable multivibrator (l2) is used generation of a horizontal sync pulse can be excited as a trigger pulse is, the output of the bistable multivibrator (12) and a signal reversed in phase with respect to this output simultaneous actuation of switching elements including one Transistor and a vacuum tube are usable, each of the two sets of video signals being selectively and alternately one Image carrier generator (8) can be supplied and the two sets of video signals can thereby be transmitted alternately in every second horizontal scanning period. 5 · Device for television signal transmission according to claim 1, characterized in that a monostable multivibrator (75) by a can be triggered by integrating, amplifying and shaping a vertical sync "chronsignal pulse, the output of the monostable multivibrator (75) to prevent the delivery of a trigger pulse for a bistable multivibrator (12) to the bistable multivibrator (12) for a certain period of time is usable during a vertical blanking period, the output of the bistable multivibrator (l2) for feeding only one of the video signals to the image carrier generator (8) at Mull and wherein the two sets of video signals through from the bistable multivibrator (l2) controlled switching elements alternately in every second horizontal scanning period to the Bildträgergenera tor (8) are supplied. 109849/1004 -I ₃ - 21U253 6. Apparatus for television signal transmission according to claim 1, characterized in that that a monostable multivibrator (75) by a by integrating, amplifying and shaping a vertical sync signal Inpule obtained can be triggered, the output of the monostable multivibrator (75) for blocking the power supply can be used to form a bistable multivibrator (12) for a specific period by means of a switching device (77), wherein the output of the bistable multivibrator (l2) can be kept at zero for a certain period and thereby the generation of an output pulse of the bistable multivibrator (12) with the first horizontal synchronizing signal following a vertical blanking period can be introduced and wherein the bistable multivibrator (12) for alternately supplying the two sets of video signals to one Image carrier generator (β) every other horizontal scanning period is actuatable. 109849/1004