SU301873A1 - - Google Patents

Description

(54) DEVICE FOR AUTOMATIC MEASUREMENT OF THE RELATION OF A SIGNAL TO A FLUCTUARY INTERFACE IN A TELEVISION TRACT

The invention relates to the field of television measurements and can be used to automatically measure and control the ratio of signal to fluctuation; Noise interference at the output of each of the sensors I of the primary video signals of the transmitting I: color television camera or at any point of the black and white television path is not; mediocre in the transmission of the television program ..

Devices are known for automatically measuring signal-to-flux ratio; noise interference in the television path, containing successively connected selection unit, pulse shaping, modulator, pulse extender, filter, functional converter, analogue; digital converter, reversible I counter, control unit and digital display:

However, in the process of transmitting a television program, known devices do not allow the ratio of the signal to i to the fluctuation interference directly at the output of each of the sensors of the primary video signals of the color, television transmitting chamber or at any point of the black-; white TV, taking into account the interference of the video signal sensor, for example, transmitting; tubes, except when a still image is transmitted.

In order to improve measurement accuracy: in the proposed device, weighting filters are included at its input, the signal from the output of which through the switch is alternately connected to one input of the modulator, the output of which through a two-channel switch is connected to the inputs of two expanders connected to the filter input via a controlled one the scheme; subtracting, wherein the narrow pulse shaping unit is a series of two generators connected in series: a belt delay, a trigger, a generator; control pulses and a generator of narrow i pulses connected to the output of the second variable delay generator, the output of the generator of narrow pulses connected to one of the inputs of the modulator and the output of the generator of control pulses to the controlled subtraction circuit and to both expanders.

Fig. 1 is a block diagram of a proposed device for automatically measuring the ratio of signal to fluctuation-5.

interference in the television path; on . FIG. 2 shows a detailed block diagram of a unit for forming narrow pulses; Fig. 3 is a schematic diagram of a controlled circuit; we are subtracting; FIGS. 4 and FIGS. 5 shows the voltage plots 110 at specific points in the block diagram of the proposed device, according to the principle of operation, I The proposed device for automatic; Measurement of the signal ratio k.15 of the fluctuation interference in the television path consists of connected-to the inputs 1-4 weighting filters 5-8 and serially connected switch 9, selection block 10, block 11 for generating 20 narrow pulses, modulator 12, two-channel switch 13 , expanders 14 and 15, controlled circuit: 16 subtraction, band-pass filter 17, attenuator 18 (low-pass filter 19), amplifier 25 20, functional conversion unit 21, analog-digital converter 22, reversible counter 23, digital indicator 24 registrations, control unit 25, unit 26

; Bivalent video signal and switches 27,

: 28 and 29.

The inputs 1-4 are connected to the inputs of the weighing filters 5-8. The frequency characteristics of the filters 6, 7 and 8 correspond to the weighting functions of the fluctuation noise for each of the channels of the video signals of the main (primary) c;} of the transmitted image, for example (; p red, green and blue. Frequency response of the filter 5 corresponds to the weighting function of fluctuation noise for the channel of the signal signal, which is similar to the weight function for the black and white television path. The outputs of the weighing filters 5–8 are connected to the inputs of the switch 9, to the output of which one of the inputs is connected block 1O of the selection, the input block 26 of the form-alignment of the equivalent video signal and one 50 of the inputs of the switch 27.

The selection block 10, also connected to the control unit 25, contains select; torus lowercase and personnel sync pulses,; a scheme for the separation of even and odd sequences of 55 frames; a scheme for separating the clock pulses of any two successive rows of even or odd half-frame. Inputs 30 and 31 of the Yu selection unit are intended for supplying lowercase and vertical driving pulses. 50

Two outputs of the selection unit 1O are connected to the inputs 32 and 33 of the block 11 for forming narrow pulses consisting of variable delay generators 34 and 35 sequentially connected to input 32, trigger 36 (connected to input 33) and generator 37 of control pulses as well as a narrow pulse generator 38 connected to the output of a variable retainer generator 35. The output of the narrow-pulse generator 38 is connected to one of the inputs of the modulator 12, the second input of which via switch 27 is connected to the OUT of the switch 9 or to the output of the video equivalent forming unit 26. The output of the modulator 12 is connected to the input of a two-channel switch 13,

The two-channel switch 13 has one more input for supplying switching pulses, connected to the output of the selection unit 10. The outputs of the two-channel switch 13 are connected to the inputs of the distributors 14 and 15,

The inputs for supplying reset pulses of the expanders 14 and 15 pulses (peak / e detectors with reset) are connected to the output of the generator 37 of control pulses of the narrow pulse shaping unit 11 (see Fig. 2), and their outputs to the input intended for supplying control pulses, controlled by the subtraction circuit 16, which is connected to the output of the generator 37 of the control pulses of the block 11 to form narrow 1 pulses. The output of the controlled subtracting circuit 16 is connected via the switch 28 to the input of the band-pass filter 17 or to the input of the low-pass filter 19.

Output strip f. Iltra 17 is connected to the input of the attenuator 18.  Through the switch 29 to the input amp. User 20 connects the output of attenuator 18 or the output of low-pass filter 19.  The output of the amplifier 20 is connected to the input of the functional conversion unit 21, consisting of a series-connected quadratic detector, an integrator, and a log-amplifier.  The output of the functional conversion unit 21 is connected to the input of the analog-to-digital converter 22, which is connected. It is also connected to the control unit 25, and its output is connected to one input of the reversible counter 23, the other input of the latter, intended to: supply reversal control pulses, connected to the control unit 25.  The output of the reversible counter 23 is connected to the digital display and recording unit 24.  At the input of the digital indication and registration unit 24, which is also connected to the control unit 25, a switch is turned on, to each of whose outputs a sequence of  A memory device, a descrambler and a digital indicator are connected.  The number of outputs of the switch and the sequence of switching corresponds to the number of inputs and sequence of switching in the switch 9.  At the input of the unit 24 (parallel to the switch), another de-embedmer is connected, to the input of which a digital printing device is connected.  The control unit 25, in addition to the connections with the units 10, 22, 23 and 24, is also connected to the switches 9, 27, 28 and 29.  A video equivalent equivalent unit 26, connected by its input to the output of switch 9 and connected to one output of the selection unit 10, consists of a series of dead-pulse level locking circuits, a peak detector with a reset, and a pulse-forming device.  The output of the video equivalent equivalent unit 26 is connected to one of the inputs of the switch 27, the other input of which is connected to the output of the switch 9.  To the output of the switch 27 is connected to one of the input (; in the modulator 12.  Inputs 39 and 40 of the controlled subtracting circuit 16 (see  FIG.  3) are connected to the outlets of the expanders 14 and 15, the input is 41 s. It is connected with the output of the generator 37 of control pulses of the block 11 for forming narrow pulses.  The control subtracting circuit 16 consists of a series-connected adder, performed on transistors 42 and 43, an emitter follower 44 on a transistor, a key stage on diodes 45-48 and an emitter repeat, l 49 H,; i transistor, and a phase inverter 50 on a transistor and a cascade 51 with a split load on the transistor.  One of the inputs of transistors 42 and 43 is connected to the input 39, and the other through an inverter 5O to the input 4O.  The key cascade on the diodes 45-48 is connected to the input 41 through a cascade with a divided load on the transistor,.  The output 52 of the proposed circuit is connected to the output of the emitter-I repeater 49 on a transistor.  To the output of the controlled subtracting circuit 16, under the "keys, the input of the switch 28.  The entire period of one dimension, t.  e.  The time during which one sample of the signal / interference ratio is obtained at the output of each of the sensors of the primary video signals of the transmitting color television camera is divided into cycles, the number of which is equal to the number of sensors of the primary video signals, for example, four (three primary color video sensors and one signal).  In turn, each of these measurement cycles, during which the signal-to-interference ratio at the output of one of the sensors of the primary video signal is measured, is divided into two main subcycles: the signal measurement subcycle and the interference measurement subcycle.  The duration and alternation of measurement cycles and subframes are set by control unit 25, which generates pulses that synchronize the operation of blocks 10, 22, 23, and 24 and control the operation of switches 9, 27, 28, and 29 that make connections for a series of blocks from cycles and measurement subcycles.  By the signal-to-fluctuation interference ratio in black-and-white television is meant the ratio of the range of the video signal between the control levels of white and black to the effective value of eg - | interferences, expressed in decibels.   Since video signals are formed in the transmitting chamber of a color television, the primary colors are similar in amplitude and time structure to a black and white television signal, and the full-color video signal is identical to it, the signal-to-fly signal ratio at the output of each of the color television transmitters is transmitted define the same as in black and white; television, taking for black level, the level of damping pulses, and for the white level - the maximum level of this I primary video signal.  Thus, one measurement period consists of several (for example, four) identical cycles, the mode of operation of each of which corresponds to the measurement in the path of a black and white television. I In the first sub-loop (measurement sub-loop; signal), the magnitude of the video signal i between the control white and black levels is measured.  If test lines are contained in the video signal, the control levels of white and black are determined by the top and bottom of a rectangular pulse (10 microseconds long), t.  e.   301 white pulses, specially entered in the interval of the test line.  For example, a video signal containing test lines 53 (see  FIG.  4), is fed to the input 1 of the proposed device, from where it is fed to the weigh-in input.  The filter 5 required for measuring the disturbance to take into account the features of its visual perception on a thermal image and having a frequency response decay only at higher video frequencies that does not affect the amplitude of the white pulse.  From the output of the cave filter 5, the video signal through the switch E is fed to the input of the selection unit 10, the input of the video signal equivalent forming unit 26 and one of the inputs of the switch 27.  In this case, when there are test lines with a white pulse in the video player, the output of the weighing filter through the switches 9 and 27 is under-. connected to one of the inputs of the modulator 12.  Thus, from the output of the weighing filter 5, a video signal containing test lines 53 with a white pulse is supplied as a modeling voltage to one of the inputs of the modulator 12. In the selection unit 10, the sync pulse of the first test line and the sync pulse are separated from the video signal. preceding the first test line, and feed them to the input 32 of the unit for forming narrow pulses (see  FIG.  2).  In addition, the input 33 of this block is served from another output, block 1O of the selection: Dedicated personnel control signal.  From input 32, dedicated, sync pulses 54 (see  FIG.  4) the specified pair of lines, following with a frame rate, are fed to the input of the variable delay generator 34 and start it with its leading edge.  From the output of the generator 34, the pulses 65 received in it are fed to the input of the generator 35 of a variable delay and start it with its falling edge.  The generators 34 and 35 are made according to the same scheme (for example, fadron) and produce sequences of paired pulses, 55 and 56, spaced apart from each other for the duration of the line and following with frequency; frames.  The duration of these pulses can vary from a few microseconds to half the length of a single line, the adjustment of the duration of the pulses 55 and 156 (in generators 34 and 35) is combined. Under the change of the signal, the duration of these pulses is set so that the falling edge is second from the pair of pulses 56 generated by the generator 35, coincides in time with the selected point located in the interval of the first test line 53 at the top of the white pulse (see  Fig. 4), while the leading edge of the first of a pair of pulses 56, leading the second pulse exactly by the row duration, coincides in time with a point located in the row interval that precedes the first test row.   The signal level at any point of the active part of the preceding line is equal to the black level in the video signal. From the variable delay generator 35 output, pulses 56 are fed to the input of the generator 38 of narrow pulses and to the input of trigger 36.  The generator 38 (for example, the block-generator generator), triggered by the trailing edge of the pulses 56, produces a sequence of paired pulses of 57 short durations (on the order of several 1 x ten nanoseconds), spreading out inter-generats; shaft row vi following frame rate.  From the generator output of 38 narrow 1 pulses, the pulses: 57 arrive at the input of the module-: torus 12, to the other input of which is in ka; As a modulating voltage, a video signal is supplied containing a test string 53 with a white pulse.  In module I, the torus 12 pulses, 57 due to its temporal position is modulated in amplitude so that the second pulse of each pair: is modulated by the level (pulse) of white contained in the first test line, and the first pulse of each pair is modulated by the black level the preceding line (see, fig, 4), as a result of che--; A go on the output of the modulator 12 is formed; a sequence of paired pulses 58 modulated in amplitude with control levels of black and white.  Pulses 58 from the output of the modulator 12 are fed to the input of a two-channel switch 13, to the other input of which is output.  Yes, the selection block 1O provides the sync pulses 54 of the above pair of lines that control the switching operation.  The first of a pair of clock pulses 54 provides switching, in which a channel is formed connecting the input of the switch 13 with that output to which the expander 14 is connected.  Through this channel, the first of the pair of pulses 58 is fed to the input of the expander 14. With the switch of the second of the pair of clock pulses 54, the switching is changed so that a channel is formed that connects the input of the switch 13 with the other. his g30 wider 15.  Through this channel, the second of a pair of pulses 58 is fed to the input of the spreader 15, In expanders 14 and 15, the first and second pair of pulses 58 expand into a field interval (half frame).  The reset in both expanders is carried out by a pulse generated by the pg of the trailing edge of the control pulse 59, which is fed to the expanders from the output of the generator of the controlled pulses of the narrow pulse shaping unit (see  FIG.  2).  The generator 37 of control pulses (for example, a multivibrator) is triggered via trigger 36 from the trailing edge of the second of a pair of pulses 56 supplied to the trigger input from the output of the variable delay generator 35.  The initial setting of the trigger 36 is carried out with the help of each sync pulse arriving at the input 33 of the block 11 forming narrow pulses from one of the outputs of the selection block 1O.  The duration of the control pulses 59 is equal to the duration of one field, and the frequency is equal to the frame frequency.  From the output of the expander 14, the expanded pulses 60, corresponding to the black level, and from the output of the expander 15, the expanded pulses 61, corresponding to the white level, are fed to the inputs of the controlled subtracting circuit 16, at the output of which the difference signal 62 appears only for the duration of the control A pulse 59, which is fed to the subtraction circuit 16 from the output of the generator 37 of control pulses of the pulse shaping unit (see  FIG.  2).  The difference signal | 62 is a sequence of next fields with a frame rate of pulses of one field duration, the amplitude of which is equal to the difference between the levels of white and black test lines 53, t.  the sweep of the video signal control levels of white and black (see  FIG.  four).  Controlled subtraction circuit 16 (see  FIG.  3) works as follows.  To the input 39 from the output of the extender 14. impulses 60 are given, and impulses 61 are fed to the input 4O from the output of expander 15.  The pulses 60 directly, and the pulse 61 through the phase inverter 50 is fed to the transistors 42 and 43.  The difference of these pulses from the output of the adder via the repeater 44 emitter-NBGy delivers c to the key stage, which is made according to the bridge circuit on diodes 45-48.  To the input 41 from the output of the generator 37 of control pulses of the block 11 for the formation of narrow pulses (see  FIG.  2) control pulses 59 are supplied, which through a split-load cascade 51 enter the diagonal bridge circuit and unlock diodes 45-48, resulting in a difference of pulses 61 and 60 for the duration of the control pulse 59 through the matching emitter follower 49 arrives at output 52.  The sequence of difference pulses 62 from the output 52 of the controlled subtracting circuit 16 is fed through the switch 28 to the input of the band-pass filter 17.  The switch 28 is controlled by pulses coming from the control unit 25, while in the signal measurement sub-loop the output of the controlled subtracting circuit 16 is connected via the switch 28 to the input of the bandpass filter 17, and in the interference measurement sub-loop to the input of the low frequency filter 19.  The average frequency of the band-pass filter 17 is equal to the pulse frequency 62, tons.  e.  frame rate.  The bandwidth of the filter 17 is chosen sufficiently narrow so as to eliminate the influence of the fluctuation disturbance on the accuracy of measuring the range of the video signal.  The first harmonic 63 of pulse sequence 62, selected by the filter 17, is a sine-wave of the frame rate, the span (double amplitude) of which is proportional to the span of the signal between the black and white reference levels.  This sinusoidal signal from the output of f-line 17 is fed to the input of the amplifier 20 through the attenuator 18 and the switch 29, which is controlled by pulses from the control unit 25.  In the subsampling: measuring the signal, the switch 29 connects the input of the amplifier 2O to the output of the attenuator 18, and in the noise measurement sub loop to the output of the low frequency filter 19.  Attenuator 18, included in the measuring channel of the proposed device only in the signal measurement sub-cycle, is designed to combine the signal sweep, which in most cases exceeds the interference amplitude not less than several times with the linear portion of the amplitude characteristic of the amplifier 20, which is used both in the interference measurement sub-cycle and and in the signal measurement subcycle.  From the output of amplifier 2O, the amplified sinusoidal signal 63 is fed to the input of block 21 of the functional converter and sequentially passes through a quadratic detector, integrator, and a logarithmic amplifier, where the effects of squares on integration (averaging) and logarithmization are performed on this signal.  The first two operations are necessary to measure the effective (rms) voltage value, which is determined in the interference measurement sub-cycle. In the signal measurement sub-cycle 63, the desired sinusoid range is uniquely determined by its effective value through a double amplitude coefficient, which can be taken into account, for example, calibration of the entire measuring channel of the proposed device.  The logarithm operation makes it possible to use the signal-to-noise ratio to use, instead of directly dividing, calculating the difference between the logarithms of the signal and the noise, as well as to obtain the final result of measuring the ratio / noise in decibels.  A signal 63 converted to a constant voltage proportional to the logarithm of the video signal amplitude from the output of the functional conversion unit 21 is fed to the input of an analog-digital converter 22, the use of which provides higher accuracy of measurements and the possibility of digital indication and recording of measurement results, in addition, can be performed, for example, according to the time pulse conversion scheme.   In this case, the incoming voltage at its input is converted into a time interval, which is filled with pulses that follow with a reference frequency.  These pulses, the number of which is proportional to the logarithm of the video signal output from the output of the analog-digital converter 22, arrive at the return air counter 23, the last one in the signal measurement cycle counts incoming pulses in the add mode and remembers their number at the next subcycle, t.  e.  subcycle change)  To control the reverse, special pulses are fed from the control unit 25 to the counter 23.  I If the video signal fed to the input 1 (or 2, 3 and 4) of the proposed device does not contain the test signals from the test lines, then in the signal measurement sub loop to one of. INPUTS of the modulator 12 through the switch 27 connects the output of the video signal equivalent forming unit 26.  The video signal coming from input 1 through the weighing filter 5 and switch 9 to the input of this unit, charges the accumulative capacity of the peak detector with a reset to a voltage equal to the span between the black and white peaks in the video signal.  A reset pulse is generated from the second sync pulse: from a select (for measuring interference) pair of lines to the reset pulse generating unit of unit 26 with one of the outputs of selection unit 10.  If the video signal is input to 1 directly. from the output of any sensor of the primary video signals of the transmitting camera of a color television or from the output of the sensor of the video signal of a black and white television (for example, a transmitting tube), then it is possible to select any two consecutive lines of even or odd half-frame to the AOR and 31 inputs Selection unit 10 serves horizontal and personnel leading pulses used to synchronize the operation of video signal sensors.  This is due to the fact that directly at the output of the video signal sensor (for example, a transmitting tube) there are no horizontal and frame sync pulses.  Impulse reset:. Sa has a duration of the order of a row and follows with a frame rate.  At the end of the reset pulse, the voltage at the output of the peak detector again reaches (within a few microseconds) the magnitude of the video signal, resulting in a voltage equivalent to the video signal coming from the output of block 26 through a switch-- mutator 27 to one of the inputs of the modulator 12 , represents the following positive square impulses, with a frame rate, and amplitude -. . which is equal to the range of the video signal between the black and white levels.  The duty cycle i of these pulses is very small, since it is equal to the ratio of the length of one line (the length of the reset pulse) to the duration of one frame, t.  e.  inverse to the number of lines in one: frame.  The falling edge of these pulses (whose temporal position is determined by the leading edge of the reset pulse) coincides in time with the beginning of the second of the selected pair of rows, therefore the sequence of pair of narrow pulses (similar to pulses 57) coming from the output of: the block 11 to the other input of the modulator 12 is modulated in amplitude with a voltage equivalent to a video signal so that the first pulse of each pair is modulated by the white level and the second by the black level.  Subsequently, the subcycle of signal measurement proceeds in the same way as in the described case with.  the presence in the video signal of the control signals of the test lines, the exception is the negative polarity of the pulses, similar to the pulses 62 and the opposite phase of the sinusoid, similar to the sinusoid 63, which does not affect the measurement result.  Thus, at the end of the first measurement cycle, both in the case of the presence of the test signals of the test lines and in the absence of those in the counter 23, the number of pulses is fixed, which is proportional to the logarithm of the range of the video signal between the counter / itiibii-. Ti by the conditions of black and white. During the second subcycle (interference measurement subcycle), the effective value of the fluctuation disturbance contained in the video signal is measured.  In the proposed device, the measurement of the effective value of the fluctuation interference voltage contained in the video signal of a moving picture of a real broadcast television program is based on the use of inter-line correlation of the video signal and the principle of averaging over the set of differences of discrete (over time) samples of the instantaneous value of the noise produced in the video signal segments, which correspond to two image elements located on the same vertical line in the frame lines adjacent in the field.  These samples are obtained by modulating in amplitude a special sequence of paired pulses spaced apart by lines and following at the frame frequency and interference voltage that is contained in the indicated parts of the video signal.  Video signal 64.  (cm.  FIG.  5) supplied to the input 1 of the proposed device, is fed to the input of the weighing filter 5 from the output of the last video signal through the switches 9 and 27 is fed to one of the inputs of the modulator 12, In addition, through the switch 9 the video signal goes to the input of the block 10 selection.  In the selection unit 1O, the sync pulses of the two subsequent lines, located in the part of the frame selected for measuring the disturbance, are selected and fed to the input 32, of the unit for forming narrow pulses (see  FIG.  2).  In addition, to the input 33 of this block, a dedicated personnel sync pulse is supplied from another output of the selection block 10. From input 32, the dedicated sync pulses 65 (see  FIG.  5) the selected pair of lines, the following with a frame rate, arrive at the input of the variable delay generator 34 and: start it with its leading edge.  From the output of the generator 34, the pulses 66 produced therein are fed to the input of the variable delay generator 36 and trigger it with its falling edge.  The generators 34 and 35 have a combined adjustment of the duration of the pulses 66 and 67 produced by them, which ensures a simultaneous half of the duration of one line.  The use of two sequentially triggered variable delay generators 34 and 35, having a common adjustment of the pulse duration, smoothly moves throughout the active part of each of the selected pairs of rows of the falling edge of the pulses 67, from which the narrow pulse generator 38 is started.  This movement is necessary in the interference measurement sub-cycle in order to be able to combine in time the narrow pulses 68 produced by the generator 38 with any point of the active part of each and selected pairs of lines.  Such movement along the lines in combination with the possibility of choosing any two consecutive lines of the even or odd half-frame in the selection block 1O ensures the movement of paired narrow pulses 68 throughout the entire frame of the transmitted image and, therefore, provides a measurement of the level of interference on any part of the television frame.  From the output of the generator 38, the pulses 68 are fed to the input of the modulator 12, to another input of which a video signal 64 is transmitted as a modulating voltage, containing interference, the level of which is to be measured.  In modulator 12, the pulses 68, due to their temporal position, are modulated in amplitude by the instantaneous values of the interference voltage contained in the parts of the video signal that are; The second ones correspond to two image elements located on the same vertical in the frame lines adjacent over the field. As a result, a sequence of pair pulses 69 modulated by amplitude i randomly is formed at the output of modulator 12, and the difference of the amplitudes of the pulses of each pair is determined by an algebraic difference only instantaneous interference values contained in. specified parts of the video signal.  This is due to the difference in static properties of the video signal and interference.  The pulses 69 from the output of the modulator 12 are fed through a dual-channel switch 13 to the inputs of the solvers 14 and 15, with the first of a pair of pulses 69 being fed to the input. the extender 14, and the second input to the expander 15, In the extenders, each of the pair of pulses 69 is extended by a field interval (half-frame).  The reset in both expanders is effected by a pulse generated from the falling edge of the control pulse 70, which is fed to the expanders from the output of the generator 37 of the control pulses of the narrow pulse shaping unit 11 (see  Fig, 2).

From the outputs of the expanders 14 and 15, the expanded pulses 71 and 72 are fed to the inputs of the controlled subtracting circuit 16, and at its output the differential signal 73 appears only during the duration of the control pulse 70. The differential pulse signal 73 is a sequence of frame frequency of pulses with a duration of one field, the amplitude of which is equal to the difference of the amplitudes of the corresponding pairs of pulses 69, i.e., equal to the algebraic differences of the instantaneous values of the interference voltages that occur in the video signal correspond to two image elements located on the same vertical line in the frame lines adjacent in the field. Since, due to strong line-to-line correlation, the levels of the video signal itself in these areas are the same, the amplitude of the HIGH-SPECIFIC pulses 73 contain information only about the level of interference.

The sequence of differential pulses: from the output 73 of the controlled subtracting circuit 16 is fed through the switch 28 to the input of the low-pass filter 19, the upper frequency of which passband is two times smaller than the following frequency, pulses 73, i.e., half the frame rate . Allocated by filter 19; The envelope 74 of the sequence, the pulse ICOB 73, is a continuous low-frequency random signal whose dispersion is twice as large (and hence the effective voltage value is / 2 times more), j than the interference dispersion contained in the video signal.

: Further, the envelope signal 74 passes through the same blocks 20, 21 and 22, i through which a sinusoidal signal 63 passes in the signal measurement sub-cycle, the span of which is proportional to the signal j span of the video signal. As a result, impulses are received at the input of the reversive counter 23, the number of which is proportional to the log, the arithm of the effective value of the interference voltage. In the noise measurement sub-cycle, the counter 23 operates in the subtraction mode, and therefore the incoming number of pulses is subtracted I from the number of pulses previously recorded in the signal measurement sub-cycle.

Thus, the number of pulses, fixed by counter 2 3 after the end of the interference measurement sub-cycle and supplied to the i Input of the digital indication and recording unit 24, is proportional to the difference of the logarithm MO in the range of the video signal and effective;

J values of the interference, i.e. the logarithm of the ratio of these quantities.

Through the switch included at the input of the unit 24 and operating in phase with the switch 9, the specified number of impulses goes to the corresponding memory device j (for example, the memory register), where it is stored for the rest of the measurement cycles (during which the signal (disturbance at the output of all other sensors of the primary video signals), i.e. before the beginning of the next measurement period. An 8 digital indicator is connected to the output of the storage device through a decoder, on which the obtained result of measuring the weighted signal-to-noise ratio is displayed directly in decibels. Digital indicators (for example, on glow indicator 0 indicator lamps), the number of which is equal to the number of sensors of primary video signals, for example, four, are located on one indicator board. Thus, after the end of all cycles. The measurements on this 5 scoreboard simultaneously induce a result; You measure the signal-to-noise ratio at |

 outputs of all sensors of primary video-out; color television transmitting camera

Deni;

In addition, after each measurement cycle, the number of pulses recorded in

reverse counter 23, enters through

, a separate decoder (included at the input of the digital display and recording unit: parallel to the switch) to a digital printing device in which it is registered to a paper tape.

Simultaneous indication of relative values;

i S / N at the outputs of all sensors of primary video signals allows you to quickly monitor the mode of operation

a color television transmission camera (or several black and white television transmission cameras) directly during a television program broadcast, which

i is very important both for the effective operation of imvi, as well as for setting up the hardware of the studio complex and other links

: television tract.

Claims (1)

For the convenience of visual monitoring of the signal / interference ratio measurement process, the proposed device can use a video monitoring device (ICS), at the input of which a video signal 64 is supplied with replaced pulses of the loudness mark. These pulses can be formed from the pulses 67; or 68 And will indicate on the screen of the ICS the pulses 68, t, i.e. indicate the detail of the television image on which the level of fluctuation interference is currently being measured. Claims i 1. Device for automatic measurement of signal-to-fluctuation interference ratio in a television path, comprising a series-connected selection unit, a pulse shaper, a modulator, a pulse extender, a filter, a functional converter, an analog-to-digital converter, a reversible counter, a control unit and a digital indicator, characterized in that, in order to improve the measurement accuracy, weighting filters are included at the device inlet 20 301 L, .JL8j. | fish-, the signal from the output of which is fed alternately by means of a switch to one input of the modulator, to the second input of which a pulse shaper is connected (Moreover, the output of the modulator through a two-channel switch is connected to the inputs of two additional pulse expanders, to which the control pulses are also fed The signals from the outputs of the additional pulse extenders are fed through a controlled subtractor to the input of the aforementioned filter. 2, The device is 1G.17 about hGH and is charged with the fact that the pulse shaper consists of two variable delay elements connected in series, a trigger, a generator of control pulses and a generator of narrow pulses, the output of which is fed to the input of the second variable delay element. 12f; 15; W Figure 2 9 GL23 . . . . I I I -four I I  I four  1 I I t II J I I I