SU1125776A1 - Television measuring signal generator - Google Patents

Abstract

A TELEVISION MEASURING SIGNAL GENERATOR containing a serially connected matching unit, a sync selector, a comparison unit, a master oscillator and a frequency divider, the output of which is connected to the second input of the comparison unit, as well as serially connected time interval shaping unit, a sinusoidal driver, a modulators unit, a unit filters, a signal addition unit and a signal input unit, the second input of which is connected to the second output of the matching unit,; the third input is with the second output of the time interval shaping unit, and the output is connected to the first input of the matching unit, the second input of which is the video signal input, and the second output is the output of the television measuring signal generator, the second output of the sinusoidal wave shaper is connected to the second input a signal addition unit, characterized in that, in order to increase the accuracy of the formation of the measurement signals, increase the reliability and enhance the functionality by changing and Structures of measurement signals, a first control unit, a programmable counter, a video signal meter, a reference driver, a second control unit and an interface block are inputted, the input of the reference signal generator is connected to the third output of the time shaping unit, the first output is with the second input of the block modulators, and the second one (O output - with the second input of the filter unit; the fourth output of the time interval shaping unit is connected to the first input of the interface unit, the second inputs of which They are inputs of external measurement signals, and the output is connected to the third input of the signal combiner, the first output of the matching unit is connected via the video parameter meter to the first input of the second control unit, the second input one of which is connected to the first output of the first control unit, the third input - with the fifth output of the time interval shaping unit, and the fourth input is the remote control input, the first output is connected to the first input of the time interval shaping unit, in Ora output - to the first input of the first control unit, and the third output - to the third input matching block, the second output of the master oscillator is coupled

Description

with the second input of the first control unit, the second output of which is connected to the input of the programmable counter, the first output of which is connected to the third input of the first control unit, the fourth input of which is connected to the output of the frequency divider, and the second and third outputs of the programmable counter are connected to the second and third inputs of the block time intervals, respectively.

The invention relates to television technology and can be used to measure the parameters of the transmission channels of a full color television signal. A known generator of television measurement signals contains a master oscillator connected via a pulse shaper to the location of the measurement signals from the clock generator and a structure organization unit connected to the output of the clock generator through the control unit and to individual sensors of the measurement signals located in the component forming unit of their components. The outputs of the sync pulse generator and the block of the organization of the structure are connected through a summing video amplifier and a prohibition block with the generator output. The prohibition unit is controlled by a self-monitoring unit, which receives signals from the outputs of the summing amplifier and the unit for organizing the U structure. The drawbacks of the device are the impossibility of generating signals of the test lines, the introduction of external measurement signals, as well as the low accuracy of the formation of measurement signals. The closest to the invention according to the technical essence is a generator of television measuring signals comprising a serially connected matching unit, a sync selector, a comparison unit, a driving generator, a frequency divider, a time interval generator, a sinusoidal wave conditioner, a modulator unit, a filter unit, a block a signal addition unit and a signal input unit, the output of which is connected to the first input of the matching unit, the second input of which is the video signal input, the second output is connected to the second The third input is the output of the television measurement signal generator, and the voltage is connected to the output of the sync stub indication block, the first and second inputs of which are connected to the output of the sync terminal and the control unit, respectively, while the second and third time interval generator outputs connected to the second inputs of the modulator unit and filter unit, respectively, and the fourth output to the third input of the signal input unit; the second output of the frequency divider is connected to torym comparing input block and the second output of the sinusoidal signals - to a second input of combining unit 2 signals. A disadvantage of the known television measuring signal generator is the low accuracy of the formation of the measuring signals and low reliability. The aim of the invention is to not accurately determine the accuracy of the formation of the measuring signals, increase the reliability of the generator of the television measuring signals and extend the functionality by changing the structure of the measuring signals. This goal is achieved by the fact that the television measurement generator. tel signals containing a serially connected matching unit, a sync selector, a comparison unit, a generator and a frequency divider, the output of which is connected to the second input of the comparison unit, as well as serially connected time interval shaping unit, shaper of sinusoidal signals, modulator block, addition filter block signals and a signal input unit, the second input is connected to the second output of the matching unit, the third input is connected to the second output of the time interval shaping unit and the output is connected to the first input of the matching unit, the second input of which is the video signal input, and the second output is the output of the television measuring signal generator, while the second output of the sinusoidal signal conditioner is connected to the second input of the adder unit, the first block control, programmable counter, video signal parameter meter, reference signal generator, second control unit and interface block, the input of the reference signal generator connected to the third output localization of the time intervals, the first output with the second input of the modulator unit, and the second output with the second input of the filter unit, a quarter of the code of the time interval shaping unit connected to the first input of the interface unit, the second inputs of which are the inputs of external measurement signals, and the encoder connected to the third input of the signal addition unit; the first output of the matching unit through the parameter meter is connected to the first input of the second control unit, the second input of which is connected to the first output of the first block the third input is the remote control signal input, the first output is connected to the first input of the time block, the second output is connected to the first input of the first control unit, and the third output is connected to the third input of the matching unit, the second output of the master oscillator is connected to the second input of the first control unit, the second output of which is connected to the input of the programmable counter, the first output of which is connected to the third in the course of the first control unit HijH, the fourth input of which is connected to the output of the frequency splitter, and the second and third outputs of the programmable counter are connected to the second and third inputs of the fore block; 1 time intervals, respectively. FIG. 1 shows a structural electrical circuit of a television measuring signal generator} in FIG. 2 is a structural electrical circuit of the first unit pack {) of the assembly and programmable counter; in fig. 3 is a structural electrical circuit of the second control unit; in fig. 4 is a structural electrical interface circuit; in fig. 5 timing diagram of the generator of television measuring signals. The television measuring signal generator contains (FIG. 1) a matching unit 1, a syncrosector 2, a comparison unit 3, a master oscillator 4, a frequency divider 5, a time interval shaping unit 6, a sinusoidal shaper 7, a modulator unit 8, a block 9 filters, a signal combining unit 10, a signal input unit 11, a first control unit 12, a programmable counter 13, a second control unit 14, a video signal parameter meter 15, a reference signal generator 16. and a conjugation block 17. The first control unit 12 and the programmable counter 13 (FIG. 2) contain a multiplexer 18, a register 19, a trigger 20, elements OR 21 and AND 22, counters 23 and 24. Information inputs and a record entry register 19, an installation input in the trigger O 20, one of the inputs of the AND element 22, one of the information inputs and the control input of the multiplexer 18 are connected to the second group of outputs of the second block 14 of the equation (Fig. 1). The second information input of the multiplexer 18 (figure 2) is connected to the second output of the master oscillator 4 (figure 1). The output of the multiplexer 18 (FIG. 2) is connected to the counting input of the first counter 24, the outputs of which are connected to the second group of inputs of the time interval formation unit 6 (FIG. 1), and the output of the first counter 24 (FIG. 2) is connected to the counting input of the second counter 23, the outputs of which are connected to the third group of inputs of the block 6 for the formation of time intervals (Fig. 1). The transfer output of the counter 23 (Fig. 2) is connected to the installation input to 1 trigger 20 and to the first input of the OR element 21, the second input of which is connected to the output of the And 22 element. The second input of the And 22 element is connected to the output of the divider 5 (Fig. 1) frequency. The output of the OR element 21 (FIG. 2) is connected to the outputs — the settings of the counters 23 and 24. The outputs of the register 19 are connected to the information inputs of the counter 23, and the output of the trigger 20 is connected to the second input of the second control unit 14 (FIG. 1). The second control unit 14 (FIG. 3 contains a computational control unit 25, display units 26, interface 27, keyboards 28, remote control adapter 29, input interface nodes 30 and 31, synchronous output node 32, output adapter 33 and interface 34 The computational control node 25 is connected via a bi-directional bus to the interface 27, the output to which is connected to the input of the indication unit 26, and the input to the output of the keyboard section 28. The inputs of the computational control node 25 are connected to the outputs of the remote controller 29 control and two. input interface 30 nodes and 31, whose inputs are connected respectively to the fifth group of outputs of the time interval formation block 6 (Fig. 1) and to the outputs of the video signal meter 15. The outputs of the computational control node 25 (Fig. 3) are connected to the input of the node 34 of the conjugate of the yoke, the outputs of which are connected to the first group of inputs of the block 6 for forming time intervals (Fig. 1), to the input of the adapter 33 of the loop (Fig. 3), the output of which is connected to the TpeTbesry input of the matching unit 1 (Fig. 1) and to the information input of the node 32 synchronous vygeoda (Fig.Z), the output of which is connected to the first group of inputs of the first control unit 12 (Fig. 1), and the synchronization output is connected to the first output of the control unit 12. The interface unit 17 contains a serially connected level correlator 35 (FIG. 4), the inputs of which receive external digital signals, a digital multiplexer 36 766 and a level coordinator 37, as well as an analog multiplexer 38, to the inputs of which external analog measurement signals arrive. The control inputs of the multiplexers 36 and 38 are connected to the fourth group of outputs of the block 6 for the formation of time intervals (Fig. 1). The outputs of the level header 37 and the multiplexer 38 are connected to the third group of inputs of the signal combining unit 10. The generator of the television measuring signals works as follows. When generating test line signals and inserting them into a video signal, the latter is fed to one of the inputs of matching unit 1 ((lg.1), which provides matching of the video signal transmission channel to input g of the generator using a passive quadrupole and one of its outputs (main) supplying the video signal to the inputs of the sync selector 2 and the meter 15 of the video signal parameters, the signal input unit 11, connects the generator input to its main output (bypass mode) in the event of power failure or a breakdown oscillator, provides power amplification of signals generated by signal injection unit 11, and supplying the latter to several generator outputs for monitoring signals on an oscilloscope, visual control of the image on the screen of a video monitor, etc. Control signal by matching unit 1 arriving at its third input is formed as follows: The video signal from the first output of block 1 is not fed to the meter .15 of the video signal parameters in which the measurement is performed, its main parameters — line frequency, p zmaha signal, the sync amplitude and others. The measurement results are digitally fed to the first input of the second control unit 14, in which they via node 31 input interface (fig.Z) supplied to the input node 25 of the calculation control. This node compares measured parameters with tolerances. If the measured parameters deviate from the specified tolerances, the node 25 generates a signal which, via adap / 11 output ter 33, controls the switching of the switch located in the matching unit 1 (Fig. 1), thereby providing a generator bypass mode. The computational control unit 25 (FIG. 3) controls the operation of the blocks of the entire generator through the interfacing nodes 30-34. The generator can change abrupt operation by the operator through the keyboard unit 28 or via the remote control adapter 29, the signals from which are sent directly to the node 25. The generator results and its status are displayed in the display node -26. In parallel with the input of the video signal meter 15 (FIG. 1), a synchro-selector p 2 is connected, in which the synchronizing pulses of the lines and fields used for inertial synchronization of the master oscillator 4 are extracted from the video signal. The master oscillator 4 generates periodic periodicity of the arc pulses, whose frequency is a multiple of the line frequency and is, for example, 10 MHz. In this case, the pulse following period is an integer number (for example, 640) less than the horizontal scanning period, and their location determines the position of the measurement signals in the horizontal intervals, in particular in the test lines. What is the frequency of the master oscillator 4, i.e. the greater the number of its pulses placed in the line interval, the more accurately the formation of the temporal parameters of the measuring signals. From the output of master oscillator 4, a sequence of pulses is fed to a frequency divider 5 with a division factor N, the output of which is connected to the second input of comparator unit 3, which manages the master oscillator 4 so that the pulse sequence of the general generator 4 is in-phase with the line pulses of the input video signal la. : 3 In this case, at the second output of gene 1 ator 4, the pulse following frequency is a multiple of the line frequency, and the Nth (640) pulse of this sequence is in phase with the lower sync. using the input video signal. These pulses go to the second input of the first control unit 12, and from there to the programmable counter 13. The first control unit 12 controls the programmable counter 13, ensuring its output signals are in sync with the frame signals of the input video signal. Depending on the mode of operation of the television measurement signal generator, the first control unit 12, following commands from the second control unit 14, changes the counting module and the synchronization mode of the programmable counter 13. To this end, the signals from the second output of the second control unit 14 are received in block 12 to register 19 (FIG. .2), to the input of the installation in O of the trigger 20, on; one of the inputs of the element And 22, as well as one of the information inputs and the control input of the multiplexer 18. Programmable counter 13 (FIG. 1) contains two series-connected counters 23 and 24 (FIG. 2). On the counting input of the counter 24 receives either a sequence of direct-. coal pulses from master oscillator 4 (Fig. 1), or pulses of the second control unit 14, which have a significantly lower repetition frequency and are used to diagnose the operation of the generator of television measurement signals (in this case, the operation of all generator blocks will be synchronized with the signals of the second control unit 14, which allows him to perform autodiagnostics for the correct formation of time intervals). The signal from the second control unit 14, which arrives at the specified input of the And 22 element (Fig. 2), provides ..., 9 its opening in the formation mode of test lines. At the same time, the frame rate signal, which arrives at the fourth input of the first control unit 12 (Fig. 1), provides for setting the counter 24 (Fig. 2). And recording from the register 19 of the code of the counting module into the counter 23. In the absence of Pulses of the frame rate of the installation of counters 23 and 24 is carried out automatically by a transfer signal coming from the output of counter 23 to the input of element SHIII 21. The same pulse is used to reset trigger 2Q, fork

the synchronization signal of the code from node 32 (FIG. 3) located in the second control unit T4 (FIG. 1). From the output of the programmable counter 13, the pulses of the line intervals and the intraline intervals enter the block 6 of the formation of the HUDC time intervals. The time interval shaping unit 6 is a multi-bit memory device (RAM) in which the time parameters of the generator are stored in the form of code sequences. These codes are synthesized in computational control unit 25 (FIG. 3) located in block 14 (FIG. 1), and they are recorded in the memory of block 6 via the output interface 34 (FIG. 3). The control of the correct formation of time intervals is also carried out by the node 25, in which, via the input interface 30, the signals generated by the time interval forming unit 6 (Fig. 1) are supplied.

According to the signals from the programmable counter. 13, the code sequences recorded in the memory of unit 6 are converted to. pulse sequences.

Consider as an example the introduction of the elements of the measurement signals in with the number 17 of damped pulses of the video signal fields. Suppose that previously input signals are transmitted in the input video signal, as shown in Fig. 5a. The signals from the keyboard unit 28 (FIG. 3) located in the second control unit 14 (FIG. 1), or the signals from the remote control input, the second control unit 14 synthesizes in the memory of the unit 6 of the time interval formation the code sequences of the time parameters of the generator blocks television measuring signals. These codes determine the location of the latching pulses of the input video signal, the quenching interval of the test line, the position of the elements of the test signals B2, B1, F and D1 (fig.Za) entered into the 17th line of the furnace pulse dashes (Fig.56), Programmable the counter 13 (figure 1) forms two groups of pulse signals: the output of the first counter 24 (figure 2) group

pulses determines the division of the interval of each row, and on the pinout of the second counter 23, a group of pulses determines the division of the frame interval into lower-case intervals. These sequences of pulses arrive at block 6 of the formation of time intervals (figure 1) and provide the reading of the code sequences of the networks recorded in the memory of this block. Block 6 has four groups of outputs of pulse sequences. The pulses used for controlling the signal inserter 11 are output at the outputs of the reference group. These include fixation pulses (Fig. 5B), the position of which corresponds to the transmission of the rear pads of lower case damping pulses of the video signal, and the beginning and end pulses of the blanking interval (Fig. 5 g). The latter ensure in block 11 (Fig. 1) the formation of the required blanking pulses (fig. 5d) and bites 5 in the video signal of previously inputted test lines and interferences (fig. 5). In another group of outputs of block 6, the pulses are selected to start the drivers a series of sinusoidal signals or the gating of continuous sinusoidal signals generated in the shaper 7 sinusoidal signals. In this case, the line should be entered in line 17

5 F containing color subcarrier

(frequency „4.43361875 MHz + 5 Hz). . At the input of the sinusoidal waveform generator 7 from block 6 pulses are applied (Fig. 5g). Of these impulses

0, a pulse is created in the former 7 of the sinusoidal signals (Fig. 5c), which provides gating for the color subcarrier and the selection of the sine wave5 packet of dal signals at one of the outputs of block 7 (Fig. 5i).

In the third group of outputs of block 6, pulses are extracted, which ensure the launch of the driver 16 reference signals containing multi-bit

 digital-to-analog converters that form rectangular signals of a given range. To form the elements B2 and B1, pulses are selected at the two outputs of the third group of block 6 (Fig. 3k) by means of which in block 16 a pulse sequence is formed (Fig. 5l). The duration of these emulsions. Determines the specified duration of the signals 2 and B1. (10 ISS and 0.166 ISS, respectively). These impulses are then located. block 9, the transition characteristic 5 of which corresponds to the sinuskvadraichnoy function. At the output of such an iltra, the signals are split (Fig. 5m) —a rectangular impulse with a sinuskadratic front and a decay of U B2 and a sine-squared impulse B1. To form a five-step D1 signal, the inputs of the T6 driver from the outputs of block 6 receive pulses (FIG. 5H), which ensure the formation of a five-step signal with steep fronts and declines at the corresponding output of block 16. The shape of the fronts and decays of the signal D 1 is strictly defined and determined by Lilt-20 rum, also included in block 9.

At the output of this filter is formed. signal D 1 (Fig. 5o). To generate pulse F, pulses (Fig. 5p) are applied to the corresponding inputs of block 16, with which, similarly to forming signals (Fig. 5l), block 16 creates a pulse (Fig. 5p) with a duration of 2 microseconds. 30 From this pulse, in the corresponding filter of the block of 8 modulators, a sinuskvadratic pulse is formed (Fig. 5c), which is fed to a pulse modulator, switched by 35 rectangular pulses with a frequency equal to the frequency of the color subcarrier and formed from a series of sinusoidal oscillations ( fig.Zi). At the output of block 8 of modulators at 40 this is the signal (FIG. 5t), which is fed to a low-pass filter in block 9, the selection signal f (FIG. 5). The signals thus formed at the outputs of block 9 of filters 45 (fig. 5m, o, y) are fed to block 3 of adding signals and further to block 2 of inputting signals, in which they are summed with the input video signal (fig.5f) 4 in where the line is preliminarily repaid,

Similarly, other elements of the test strings and other signals are formed.

Additional features of the generator as a universal input device for external signals are associated with the introduction of a conjugation block 1.7 into its circuit. This block provides the possibility of introducing an external video signal such as signals of time and frequency standards, teletext signals, digital audio signals, measuring signals of an oscillating frequency to evaluate the sideband characteristics of television transmitters, etc.

Switching pulses of external measurement signals are formed on the fourth group of outputs of block 6 in the same way as described method and are fed in block 17 to control digital 36 (FIG. 4) and analog 30 multiplexers. External analog signals are fed to the information inputs of the multiplexers 38 directly, and external digital signals are fed to the information inputs of the multiplexer 36 via a level matcher 35.

Simple calibrated signals directly from the output of the multiplexer 38 and from the output of the multiplexer 36 through the level matcher 37 are fed to the third group of inputs of the block 3 (Fig. 1) of the sum of the signals. ,

Thus, the proposed generator of television measuring signals, by introducing blocks 12-14, is simpler known, which, in turn, along with the introduction of self-monitoring functions, provides an increase in the reliability of the generator. The introduction of a reference driver improves the accuracy of the formation of output signals.

In addition, it is possible to form periodic measurement signals that are not associated with an external video signal, input measurement, test and other signals generated by external devices in the video signal.

The generated measurement signals can be composed in any set of any elements formed by blocks 7–9 and 16 (FIG. 1).

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Claims (1)

A television measuring signal generator comprising serially connected matching unit, a sync selector, a comparator, a master oscillator and a frequency divider, the output of which is connected to the second input of the comparator, as well as serially connected time interval generating unit, sinusoidal signal generator, modulator unit, filter unit , a signal addition unit and a signal input unit, the second input of which is connected to the second output of the matching unit: the third input is with the second output of the pho block time intervals, and the output is connected to the first input of the matching unit, the second input of which is the input of the video signal, and the second output is the output of the television measuring signal generator, while the second output of the sinusoidal signal generator is connected to the second input of the signal addition unit, characterized in that, in order to increase the accuracy of the formation of measuring signals, increase reliability and expand the functionality by changing the structure of the measuring signals, introduced the first control unit, a programmable counter, a video signal parameter meter, a reference signal shaper, a second control block and a pairing unit, the input of the signal shaper being connected to the third output of the time interval generating block, the first output to the second input of the modulator block, and the second output to with the second input of the filter unit, the fourth output of the time interval forming unit is connected to the first input of the interface unit, the second inputs of which are inputs of external measuring signals and the output is connected to the third input of the signal addition unit, the first output of the matching unit through the video signal meter is connected to the first input of the second control unit, the second input: one of which is connected to the first output of the first control unit, the third input to the fifth output of the unit the formation of time intervals, and the fourth input is the input of the remote control signals, the first output is connected to the first input of the time interval forming unit, the second output is connected to the first input of the first control unit, and s output - to the third input acceptance unit, the second output of the master oscillator is connected> with the second input of the first control unit, the second output of which is connected to the input of the programmable counter, the first output of which is connected to the third input of the first control unit, the quarter® input of which is connected to the output of the frequency divider, and the second and third outputs of the programmable counter are connected to the second and third the inputs of the unit for the formation of time intervals, respectively. ¹ 2