RU1777071C - Acoustic microscope for timely examination of object - Google Patents

Abstract

The invention relates to a measurement technique and can be used for non-destructive testing of materials. The purpose of the invention is to expand operational capabilities by increasing the speed of obtaining related images of a controlled object. An acoustic microscope with analog storing and displaying signals on an afterglow oscilloscope tube allows quick and quasi-continuous viewing of connected images without loss of resolution and detail of observation of controlled objects whose dimensions exceed the information capabilities of the memory and visualization unit. For implementation, block 32 is introduced into the microscope circuit settings of the shift value of the scanning raster, the counting circuit 26 and the formation of the horizontal and frame sync pulses control circuit, reverse frame rate control circuits 25 that effect a controlled shift of the scan raster over the object and the displayed area on the screen. 2 silt (L C

Description

The invention relates to β-equipment for non-destructive testing of materials and products using focused ultrasonic and hypersonic waves

Known lens acoustic microscopes in which analog devices for storing and displaying signals are used - oscillographic cathode ray tubes with afterglow. Due to the limited size of the screen, it is possible to remember and simultaneously display the acoustic image, as a rule, of a small part of the controlled object

An attempt to increase the area of a sample by displaying at intervals exceeding the resolution of the microscope leads to a loss of detail in the image of the object, and hence the reliability

The aim of the invention is an acoustic microscope that allows efficiently performing quick and quasi-continuous viewing of connected images without loss of resolution and detail of observation of controlled objects, the dimensions of which exceed the information capabilities of analogue memory and ritualization devices

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one-time storage and display of the entire object or a significant part of it.

This goal is achieved by the fact that in an acoustic microscope with analog storage, containing a transmitting unit, an acoustic lens element, a receiving unit connected by a three-arm circulator or a directional coupler, an afterglow oscilloscope tube, a device for mechanical scanning of the acoustic beam over the surface of a controlled object, a device for time synchronization of the operation of the above devices, according to the invention, a block of settings for the amount of shift of the scanning raster is added Ani counting circuit and generating a horizontal and vertical sync control scanning circuit controlling the magnitude of reverse human stroke soedinen- nye accordance with the scheme which is carried out controlled by the shift of the raster scan for the object and, consequently, the imaged area on the screen.

Comparative analysis with the prototype shows that the claimed solution is distinguished by the above-mentioned added schemes, which provide a shift of the scanning raster across the object, and therefore, the plot displayed on the screen in time. This inventive device meets the criteria of the invention of novelty.

Comparison of the claimed solution with other technical solutions in the art did not reveal any signs distinguishing it from the prototype, which meets the criterion of significant differences.

Figure 1 shows the structural-functional diagram of a lens acoustic microscope (LAM) with analog storing and display on an oscillographic graph tube with afterglow; Figures 2a, b show the scanning order of an object and the process of changing the image formed on the tube screen.

LAM consists of a transmitter unit 1, the output of which is connected to the input of the circulator 2, the first output of which is connected to the transducer 3 of the acoustic lens element (ALE) 4, and the second output is connected to the information input of the receiver unit 8. From the output, the amplified signal is supplied to the electrode of the tube of the indicator unit 28, modulating the brightness of the beam. The inputs of the deflecting system of the indicator block 28 are connected to the outputs xy of the scanner 27. This block, as well as the reverse control circuits 25, and the comparator circuit 30 are connected by the supply lines of horizontal (SSI) and personnel (CSI) synchronizing pulses to the counting and generation circuit 26, which in turn is connected via the control lines to the comparator 30 and the shift setting unit 32. The output of the 1K mode (one frame shift) of the latter is connected to the input of the reverse turn-off circuit 29, the output of which is connected to the control input of the reverse control circuit 25. Dv release of this

0 circuits are connected along the control lines of the scanning direction with the control inputs of the mechanical scanning unit 18. The synchronization inputs of the transmitting 1, receiving 8 blocks, counting circuits and formations 26 and the trigger input of the scanning unit 18 are connected. With the corresponding outputs of the synchronization block 17, which triggers it the pulse of the beginning of the line comes along the line from block 18.

0 The device operates as follows. The amplitude-modulated pulsed electrical oscillations of the transmitting unit I are transmitted through a circulator 2 to the electro-acoustic transducer 3 of the ALE 4 and the acoustic wave, after being refracted by the lens 5, focuses on the object 7 and, after reflection from it, has passed the opposite path and acoustoelectric conversion through the 3rd shoulder the circulator 2 enters the receiver 8. and after amplification in it, a signal is supplied to the tube electrode of the indicator unit 28, modulating the brightness of the recording electron beam. The movement of the beam on the screen of the tube of the indicator 28 along the x and y axes is synchronized by pulses from block 17. with the scanning of the acoustic beam over the surface of the object in the x and y directions, implemented by the scanning unit 18. This is achieved

0 correspondence of the position of the elements on the scanned area of the object and the points of the acoustic image on the screen. A sufficiently high resolution tube usually retains a visible image for

5 seconds defining the time to receive one Tk frame. Therefore, in order to observe a stable image, it must be resumed through the interval Tk by rescanning

0 for the same section. To do this, the scanning device after completing the next frame should return the acoustic beam to the beginning of the first strip of the same section of the object.

5 The difference in the operation of our microscope is that the beam returns to the beginning of the second or next lines of stripes of the portion of the object scanned in the previous frame. Since the beam scan always starts from one place on the screen,

a new frame will begin with the image of the new first strip of the scanned area. The lines released at the end of the frame will be filled with the image of the continuation of the scanned area in the direction of frame scanning. If the shift process during the reverse stroke of the frame scanner is continued, then the image of the whole strip of the object will run on the screen by alternating frames. To implement this process, new elements have been added to the microscope circuit.

The counting and shaping circuit 26, receiving pulses from the synchronization block 17, synchronous with the pulses of the beginning of the scan line, recalculates their number on the forward and backward strokes of the scanner and generates the corresponding frame (CSI) and lowercase (SSI) clock pulses for the scanning system 18 and block sweeps 27 of the beam of the indicator 28. The shift setting unit 32 is used to select the frame shift value by the operator, those. the part of moving the scanner along the y axis, to which it will not reach during the reverse (reverse) stroke. It can be expressed in fractions of a frame - 0.5 K, 0.25 K ..., or the number of lines - 1 s, 0 s. The OS mode corresponds to the repetition of scanning and image of the same area of the object. Installation on block 32 of shift 1, OK, i.e. over the entire length of the frame, corresponds to the continuous movement of the scanner and the image on the screen along the y axis in the forward direction. The reverse turn-off circuit 29 is carried out together with the reverse control circuit 25 in the reverse direction of the scanner. My move. Regardless of the reverse shift setting, the scanner 27 must generate signals that return the electron beam of the indicator 28 to the starting point of the image raster by the time each new scanning period begins.

The proposed functional diagram works as follows.

Depending on the required viewing mode of the monitored object — with the frame being erased, the image of the selected section being repeated, or in the run mode — the corresponding button on the shift setting unit 32 is pressed. A quick scan starts with the Start signal, and start line pulses start the line starting the formation of clock and g.rochnyh pulses. The former launches the ground and receiver blocks to obtain the LAM theft, which is fed to the modulator l

indicator 28 (input). Horizontal sync pulses (SSIs) are supplied to the counting circuit 26. where they are used to form SSIs and SSIs, which trigger the scanning unit 27 of indicator 28 and SSIs of the forward scanner 18. After counting the specified number of pulse pulses in the frame, a signal is generated to reverse the motion in the y direction. Re-counting counters. Comparator 30 compares the countdown code with that set on block 32 and, once they match, generates a pulse to stop the reverse movement. After that, the counters are reset and from the block 26 through the circuit 25 they begin to flow back to the forward-scanning direct-current scanning system 18.

In run mode, when button 1 is pressed, OK, the reverse turn-off circuit is turned on, prohibiting reverse. In this case, the movement along the y axis occurs in one direction, the counters operate in a cyclic mode, and on the screen of the indicator 28 images of successive sections of the object’s viewing strip appear sequentially. After reaching the edge of the object by switching the direction signal (block 17), the movement along the y-axis is stopped, the transition to the adjacent lane is started, and the measurements are started with the movement in the opposite direction or in the same direction of the y-axis after preliminary returning to the beginning of the previous lane.

As illustrated in Fig. 2a, an object is scanned in stripes by quickly scanning at a magnitude of Ax and slowly moving the entire length of the object in the y direction. After reaching the edge, the mechanical device moves the beam stepwise by the distance Ax along the x axis, and scanning of the next strip begins with the movement along the y axis in the opposite direction. The trajectory of the slow (frame) scan is shown by a zigzag dashed line

The time of viewing an object using the proposed LAM, which determines the speed of viewing, depends not only on the surface area, but primarily on the speed (frequency) of line scanning and resolution (working frequency) of the microscope. For example, at a line frequency of 50 Hz, a frame of 250 lines can be displayed in 5 s. If the operating frequency of the LAM is 1 GHz and the surface resolution with water as an immersion liquid is 1.5 μm, then the length of such a frame will be 1.5x250 μm 375 μm. The highest viewing speed is achieved when shifting per frame (1 K mode on the block

setting of the shift 32) and will be 75 μm / s With a scan frame width of Ax 1.5 x x 250 μm 375 μm, viewing an object with dimensions of 3.75 mm x 3.75 mm will require about 5x10x10 500 with 6.3 min of time without taking into account the cost of moving to the next (out of 9) scan bands. Such viewing efficiency is not possible with analogues using the manual method of transition from frame to frame.

Claims (1)

Compared with known acoustic microscopes, the proposed LAM has the following advantages: the ability to observe coherent (within the scanning band) images; increased performance review of controlled objects; the possibility of express diagnostics of objects with a large length both by the operator and by means of computational tools connected in addition to the output of the receiver; a combination of operational diagnostics with an in-depth analysis of the selected fragments of objects (after turning on the OS mode on the shift setting block 32); the ability to fairly accurately determine the coordinates of a defect by counting stripes and lines. SUMMARY OF THE INVENTION An acoustic microscope for quick viewing of an object comprising a transmitting unit connected by a directional coupler, an acoustic lens element, a receiving unit, in series analog-to-digital converter, storage device, buffer memory, memory switch, digital-to-analog converter, video control device, address switch, write and read address counters, synchronization and scanning unit, pair outputs of counting elements and lines of address counters connected to the output of the receiving unit write and read addresses are connected to the paired inputs of the address switch, the output of which is connected to the address input of the storage device, and the inputs synchronizing with the needles of all the blocks and devices are connected to the corresponding outputs of the synchronization block, characterized in that, in order to expand operational capabilities by increasing the speed of obtaining connected images of a monitored object, the dimensions of which exceed the information capabilities of memory and display devices, it is equipped with a scan line counter and an adder addresses of scan and read lines, the output of a cyclic scan line counter connected to the first input of the adder, the second input with mmatora connected to the output read address counter, the output of the adder is connected to the input lines of the switch account addresses, clock inputs of the line counter and an adder connected to the outputs of synchronizing unit Fie / RC PI HMfbfiA .... "Wft W ./) yeutww HQ4CUIO and FIG. 2 5