SU373900A1 - DEVICE FOR ISOLATION ELEMENT SELECTION IN A TELEVISION METER - Google Patents

Description

I

The device relates to the field of television measurements and can be used in meters. video signal distortion of the test television image generated by a transmitting camera having an orbiter.

A device for extracting an image element in a television meter, comprising a serially connected synchronization unit and an adjustable selection unit for the line under investigation, is pa and an output unit for generating a selection element for a video signal element in a line is output. Such a device does not allow measurement of the distortion of the video signal of the test images if the video signal is generated by the transmitting camera with the orbiter turned on.

The aim of the invention is the implementation of the ability to measure the distortion of the video signal generated by the transmitting camera when the orbiter is on. This is achieved by the fact that between the block of the regulated, selection of the line under study and the block of formation of the pulse of the selection of the video signal element in the line there is a block of the selection of the reference vertical contour, two outputs and one of the inputs of which are connected. They are not equipped with a dual phase detector unit, and the third input is connected to a video pre-processing unit. The latter is connected to the input of the device. The output of the synchronization unit connected in series connected unit adjustable

selection of the reference line and the block of the formation of the error signal vertically, the second input of which is connected to another output of the synchronization unit, and the output - to the corresponding inputs of the blocks of adjustable selection of the reference and investigated lines. FIG. 1 shows a block diagram of the proposed device; in fig. 2 shows diagrams for explaining the principle of selection of an image element in the vertical direction.

raster; in fig. 3 - diagrams, explaining the principle of selection of the image element in the horizontal direction of the raster.

The device consists of a block / synchronization, block 2 of an adjustable reference line, block 2 of an adjustable selection of the line under investigation, block 4 of the formation of the error signal vertically, block 5 of the reference vertical contour selection, block 6 of a double phase detector, block

7, a video signal pre-processing unit and a pulse generation unit 8 for extracting a video signal element in a row.

The inclusion of the orbiter provides for smooth image movement in the longitudinal

and the transverse directions of the raster relative to the synchronizing impulses. To isolate any video signal element with the switched on orbiter during the measurement time, the device compensates for the displacement of the image element in the vertical and horizontal. From the video source to the input 9 of the device receives the full video signal. In the selector 10 of block 1, the line sync mixture and the field frequency pulses are separated from the full video signal (Fig. 2, a). The sync mixture enters the V / auto phase trim circuit, which serves to generate horizontal frequency pulses that coincide in phase with the horizontal sync pulses. Pulses from the frequency of the fields in divider 12 are formed into two pulses that follow with a frame rate. The horizontal frequency pulses are fed to the inputs of two similar blocks 2 and 5, consisting of circuits 13, 14, gain, dividers 15, 16 by 312, and triggers 17, 18, respectively.

Block 2 is designed to separate the line from any clear contour of the image. If a clear horizontal imaging contour is selected, then in block 4 a pulse is generated, which dampens one pulse from the number formed by the circuit in circuit 13. In this case, the leading edge of the pulse at the output of divider 15 corresponds to the number of the same one: the same line allocated in each frame. When, due to the action of the orbiter, the selected element of the image is displaced vertically by at least one line in any direction relative to the selected one, the output of block 4 either does not generate a pulse at all, or produces a dh of a pulse of damping, which dampens two pulses of the number generated scheme //.

In the first case, the power-on circuit 13 transmits all pulses to the input of the divider 15, and at its output in each subsequent frame, the synchroimpulse line corresponds to the falling edge of the pulse, the number is one less.

In the second case, in each subsequent frame, the falling edge of the pulse formed by the divider 15 corresponds to the sync pulse of the row, which is the same number as the unit.

The trigger 17 is triggered by the falling edge of the pulses generated by the divider 15. This trigger is reset by pulses following the frame rate generated by the divider 12. Thus, at the output of the trigger 17, pulses are generated whose trailing edge corresponds to the selected line sync pulse (Fig. 2, b).

The switch 19 of block 2 serves to preselect the auxiliary contour in the image.

The pulses from the output of block 2 trigger the trigger 20 of block 4, which is reset by the first incoming sync pulse from the output of selector 10 of block 1. The pulses (Fig. 2, c) from the output of trigger 20 are differentiated and fed to the input of circuit 21 "OR,

pulses from the trigger / 7 are fed to another input. As a result, pulses (Fig. 2, d) are formed at the output of circuit 21, corresponding to the fronts of the clock pulses of two s. Adjacent lines. These pulses trigger the generator 22, which generates pulses (Fig. 2, d within the duration of one line). A strobe pulse generator 23 is generated from the trailing edge of the generated pulses (Fig. 2, e, of the order of 30 nsec. Pulses from the generator output 23 are fed to the input of the gating cascade 24. The cascade operates in such a way that, if the gating pulse coincides with the level close to the white level of the video signal, then an output appears impulse; if it coincides with the level close to the black level of the video Igna, the output pulse is absent, - B

Depending on the position of the selected line relative to the image contour, there can be two pulses at the output of the gating cascade, one pulse, not a single pulse. Each of these pulses triggers a generator 25, which generates pulses (Fig. 2, l with a duration slightly shorter than the row. These pulses are fed to the input of the dithering circuit 13. The presence of two dither pulses at the output of the generator 25 corresponds to the downward movement of the selected row from frame to frame over a raster, a single impulse damping — stopping the movement and the absence of impulses — moving the line selected from frame to frame up the raster.

Any contour offset relative to the selected line due to the orbiter causes the appearance of correction pulses at the output of generator 25, which change the number of the line to be selected. Pulses from the generator

25 are also fed to the input of circuit 4 for block 4.

Block 5 is intended to isolate the line under study within the raster, which is done by switches 26 and 27. If the switches are closed, the circuit 14 is bypassed and the back edge of the pulse at the output of trigger 18 moves from frame to frame up the raster. If the switch 26 is open and the switch 27 is closed, then the back edge of the pulse at the output of the trigger 18 does not move, unless the back edge of the pulse at the output of the trigger 17 moves.

The pulse (Fig. 3, a) from the output of the trigger 18, the leading front of which is slightly ahead

in time, the sync pulse (fig. 3, b) of the extracted line, with its leading edge, launches fadron 28 of block 5. The fantastron forms pulses (fig. 3, c) with a duration adjustable within the line. The duration of the pulses formed by the phdron, is controlled by a constant voltage applied to the input 29 and passing previously through the addition circuit 30. The frontage of fadron 28 pulses triggers generators 31 and 32. Generator 31 generates pulses (Fig. 3, d) of duration t, generator 32 — pulses (Fig. 3, e) of duration t / 2. An impulse from the output of the generator 31 is fed to the input of the circuit 33 "And, to the other input of which video impulses come from the output of block 7.

In block 7, the video signal from input 9 is fed to an optimal filter 34, the task of which is to obtain at the output a maximum signal to fluctuation interference ratio in the video signal. From the filter 34, a differentiated video signal (Fig. 3, e) is fed to a shaper 35, in which pulses are formed (Fig. 3, g, resulting from a two-sided limitation of the signal from the filter 34. In this case, at the input of the filter 34 Controlled locking. From the output of shaper 35, pulses are fed to circuit 33. When the leading edge of one of the pulses of shaper 35 coincides with a pulse of generator 31, an impulse appears in the output of circuit 33 (FIG. 3, c), from which the selection circuit starts element in the string phantastron 37 on the unit 8.

The video element under investigation in the line is manually or automatically selected using the control voltage supplied to the input 38 and changing the pulse duration (Fig. 3, s) of Fettron 37. Fadron's pulse 37 triggers its back front to launch Fredron 39. The latter generates a pulse (Fig 3, k), from the trailing edge of which a pulse is triggered, analyzing the form of the video signal in a device connected to output 40. The law by which the analyzed video signal elements are selected in a row is given as voltage from source connected to input 41.

The pulse from the output of the generator 32 is fed to the input of the trigger 42 of the block 6. The task of this block is to monitor the trailing edge of the fudrone 28. The pulses (Fig. 3, lm) of different polarity obtained at the outputs of the trigger 42 are fed to the circuits 43 and 44 "And, to the second inputs of which pulses are supplied from the output of circuit 33" I. The pulses from the outputs of circuits 43 and 44 are folded

in the circuit 45 "OR and then the reversing counter 46 is started, to which the decadating matrix 47 is connected. The trigger 48 is tilted if the output of the circuit 43 or 44

pulses appear. In this case, the trigger 48 controls the reverse of the counter 46. Depending on the position of the pulse at the output of the circuit 33 relative to the falling edge of the pulse of the generator 32, the addition or subtraction of the pulses in the counter is carried out. This leads to a change in the DC voltage at the output of the matrix 47, which controls the duration of the pulses of the fadron 28, passing previously through the circuit 30

addin

FIG. For direct 49 - the level of video signal differentiation.

Subject invention

20.

A device for extracting an image element in a television meter, containing a serially connected synchronization unit and an adjustable selection unit for the line under investigation, and an output unit for generating a video element extraction unit pulse in the line, characterized in that, in order to make it possible to measure the distortion of the video signal, formed by the transmitting camera when the orbiter is on, between the block of controlled selection of the line under study and the block of formation of the pulse audio video included in the line unit

the selection of the reference vertical circuit, two outputs and one of the inputs of which are connected to the dual phase detector unit and the third input of which is connected to the video preprocessing unit 01, which is connected to the input of the device; and to the output of the synchronization unit, connected in series, a unit for adjustable separation of the reference line and a unit for generating the error signal along

vertical, the second input of which is connected to another output of the synchronization unit, and the output - to the corresponding inputs of the blocks of the controlled selection of the reference and exploring rows.

/ Ch / l /.-.

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