DD221545A1 - CIRCUIT ARRANGEMENT FOR TOUCHLESS MEASUREMENT OF PRUEFLINGS - Google Patents

Abstract

Circuit arrangement for the contactless measurement of test specimens, wherein both the distance of the outer contours of transparent and complicated non-transparent test specimens to one another and their position recognition using a photosensor arrangement whose image content is available as binarized image information and the shadow projection method can be determined. The present video signal of the photosensor arrangement is fed on the one hand to a discriminator and on the other hand to a fast-acting memory device. The discriminator controls a gate circuit, wherein the first light-dark transition causes the closing of the gate. Connected downstream of the gate circuit is a pixel counter, which counts the pixel pulses passing through the gate circuit until the appearance of the first light-dark transition. After the end of a line duration, the memory device is read out in the opposite direction to the input and the readout pulses fed to the discriminator and the gate circuit via an OR circuit, whereby the pixel counter its state by the number of pixels of the opposite photosensor side, which are brightly lit, changed. Fig. 1

Description

Title:

Circuit arrangement · for non-contact measurement of test objects

Field of application of the invention :

The invention is suitable for Yermessen the distance of the outer contours of transparent and complicated non-transparent specimens to each other as well as the position detection of the same.

It can thus be used in the glass tubes as well as semifinished and end product for optical fiber manufacturing industry as well as industrial robots,

Characteristic of the known technical solutions:

For the measurement of glass tubes v / earth in newer devices, such. Zygo Corporation / USA, special microcomputer used for signal processing in determining the diameter using the shadow projection method »

There are also known measuring methods in which the body to be measured is imaged by a light source onto a micrometer bar provided with HeIl dark markings and the

IQ unobscured light-dark marks scanned by a photocell by mechanical reciprocation of a mirror and the pulses generated counted and displayed (DE-OS 2046518).

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It is also known to image a body to be measured on a matrix provided with light-dark markings which is scanned by a television camera (DE-OS 2211343) or to directly draw a television camera for counting the darkened image cell and thus for determining the diameter. All of these methods have high reliability, high processing speed, high cost, low cost, and low visual cost, low reliability.

Object of the invention:

The aim of the invention is to provide a cost-effective, reliable, working at high speed non-contact measuring method both for measuring the distance of the outer contours of transparent or complicated non-transparent test specimens to each other and for detecting the position of the same with the least possible circuit complexity.

Explanation of the essence of the invention:

The invention has for its object to provide a simple circuit arrangement for the contactless measurement of the Abstands of the outer contours of transparent or complicated non-transparent specimens each other and for position detection thereof using a single sensor array and the shadow projection method, the electronic signal processing at high speed and Reliability works, the

evaluating or signal processing electronics bring no additional uncertainties and are used to control the circuitry native signals «

The object is achieved by a circuit arrangement which is connected downstream of an arrangement in which a radiation source, a collimator, a test object, an objective, a telecentric diaphragm and a row or areally constructed photosensor arrangement are provided along one optical axis and the image contents of the photosensor arrangement in that a binarized image information is present in a video signal fyjDgQ, and the output signal of the circuit arrangement is supplied to a pixel counter, according to the invention in that a start signal logic for forming a pulse coincident with the first image pulse from a native signal f with the set input of a first flip-flop Flop is connected, that the output of the first flip-flop with the input of a first gate circuit, at whose second input an equal to the video signal synchronized synchronized clock pulse f ^. is connected, and the output of the first gate circuit leads to the up-counting input of a forward / backward counter whose address outputs with a first decoder for detecting the most significant address, with a second decoder for recognizing the least significant address and the address inputs of a Read-write memory are connected, that the output signal of the first decoder to the reset input of the first and the set input of a second flip-flop and the output signal of the second decoder to the reset input of the second flip-flop and. a discriminator leads, wherein the output of the second flip-flop is connected to the input of a second gate circuit whose second input is coupled to the clock pulse fn / up and whose output leads to the Rückwärtszähleringang the up / down counter that the first decoder with the entrance for the.

Operating state for the read-write memory is connected and that the video signal £ γτ-η _{Ε0 leads} to the data input of the _random access memory and to an input of an OR circuit, the data output of the random access memory with a second input the OR circuit is connected, the output of the OR circuit and the native signal f input signals of the discriminator form and the output of the discriminator and the output of the OR circuit to the inputs of a third, coupled to the pixel counter, gate are connected.

The circuit arrangement according to the invention operates in conjunction with the linear or planar foiosensor arrangement which can be read out line-by-line and whose image content is available in time-discontinuous form or can be converted into such a form.

The image contents available in such a form are supplied in binarised form in the video signal fyj _DE o of ^the circuit arrangement according to ^the invention. The present video signal is fed on the one hand to a discriminator circuit and on the other hand to a fast-operating memory device (RAM). The discriminator circuit in turn controls a gate circuit which is connected to the pixel counter, wherein the first light-dark transition causes the closure of the gate.

After the end of a line duration, the memory device is read in the opposite direction to the input and the information is fed to the discriminator and the gate circuit via an OR circuit. The pixel counter changes its state by the number of pixels of the opposite side of the photosensor array, which are brightly illuminated. "Necessary for this method of operation is the extension of the line scan time by the memory readout duration.

Embodiment ; '. ,

The invention will be explained in more detail with reference to an embodiment shown in the drawing.

1 shows the circuit arrangement according to the invention

2 shows an optical arrangement with a photo sensor arrangement for the shadow projection method

FIG. 3 shows an embodiment of the circuit arrangement according to the invention, in particular for the measurement of the position detection

Fig. 4 shows an embodiment of the circuit arrangement according to the invention for the simultaneous detection of the distance of the outer contours and the position of the specimen.

The arrangement according to the invention is used in conjunction with the shadow projection method, which consists in the composition of the elements radiation source 1, collimator 2, object to be measured 3, objective 4, telecentric diaphragm 5, photosensor arrangement 6, which are arranged along an optical axis 7 (FIG .2).

The photosensor arrangement 6 has a line or areal design. The pixel contents must be supplied in time-discontinuous form according to the order of their geometric arrangement (line by line for areal arrangements) to a trigger circuit (not shown). The now binarized image information v / ird in the form of the video signal fed fyjjjgQ the inventive arrangement

 The arrangement according to the invention is constructed as follows:

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The output of a start signal logic 8, at whose input the native signal f is present, is connected to the set input of a flip-flop 9. The output of the flip-flop 9 leads to an input of a gate circuit 10, at whose second input a clock pulse fj ^ / p ^ is applied. The output of the gate 10 is coupled to the count-up input C of a gate-down counter 11, whose address outputs A are connected to a decoder 12 and a decoder 16 and to the address inputs A of a Sohreib-read memory 13 · The output of the decoder 12 leads to the reset input of the flip-flop 9 and to the set input of a flip-flop 14, the output signal of the decoder 16 leads to the reset input of the flip-flop 14 and to a discriminator 18th The output of the flip-flop 14 is connected to an input of a gate circuit 15, to the second input of the gate 15 leads the clock pulse ^ DATA. * The output of the gate 15 is coupled to the Rückwärts counting input C _{R of} the front-back counter 11. Furthermore, the decoder 12 is connected to the input for the operating state of the read-write memory 13 in connection. -An the data input of the read-write memory, the video signal ίγτ ^^ η ' ^E i & ^e the read-write memory 13 connected downstream OR circuit 17 is connected to the video signal fyr-QgQ ^{and the} -Ausgangs signal of the read-write Memory 13 occupied, the output of the OR circuit 17 and the native signal f lead to inputs of the discriminator 18th The output of the discriminator 18 and the output of the OR circuit 17 are connected to the inputs of an OR circuit 19 whose output is connected to a pixel counter "The start signal logic 8 forms a pulse from a native signal (eg. B _e vertical or

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Horizontal sync pulse in television systems or "fx" in CCD lines), which coincides in time with the first image pulse. This start pulse sets the flip-flop 9 and thus opens the gate 10th

An equal to the Yideotakt gleichfreq.uenter and synchronized clock "fTw \ m / \" passes through the gate 10 to the Yor- / Rückwärtszähler 11 to the count-up input C. The counter 11 forms the addresses for the random access memory 13, the amount of addresses depending on the number of pixels per line. Upon reaching the most significant address, the decoder circuit 12 forms a signal for resetting the flip-flop 9 and for setting the flip-flop 14th "^ tuta" g ^ ⁹ - ¹¹ ^ thus to the count-down input C _{R of} the counter 11.

At the same time, the static random access memory is activated to output its data. The output of the data is opposite to the input, that is, the first bit output corresponds to the last pixel of a line of the photosensor array. When the least significant bit of the address extent is reached, a decoder circuit 16 generates a signal to reset the flip-flop 14 and thus to block the gate 15.

The detection of the least and most significant bits of the address size is made possible by decoding the addresses or by using the carry pulses of modern counter circuits. A discriminator circuit 18 forms a control signal for closing the gate 19 when the first light-dark transition occurs. The discriminator circuit 18 is controlled by the native start signal f and by signals of the decoder circuit 12 or 16.

For the measurement of diameters, lengths and widths, distances and the like. it makes sense to use both pulse trains, i. the pulse sequence entered in the direction of the geometric arrangement of the individual pixels, such as the opposite direction via an OR shutter 17, 'the discriminator circuit 18 and a gate 19 to a pixel counter to supply (Figure 1).

For position detection "it is more advantageous to supply the two signal sequences to two pixel counters operating independently of one another (FIG. 3)

Thus, the use of two reference points is possible to set an optimal assembly or joining game for transparent or complicated non-transparent specimens, sometimes it is advantageous to combine the two variants with each other, at the same time the distance of the outer contours to each other and the position of the specimen to determine fixed reference points. (Fig.4)

Claims (1)

Pat entitlement Circuit arrangement for non-contact measurement τοη DUTs, both the distance of the outer contours of transparent and complicated non-transparent test specimens determined as well as a position ^ recognizing the same can be made, the circuit arrangement of an array is followed, in which along an optical axis one after the other Radiation source, a collimator, the specimen, a lens, a teletubtric aperture and a line or areal constructed photosensor arrangement are provided and the image contents of the photosensor array as binarized image information in a video signal fy-r-rrgo and the output of the circuit arrangement a pixel counter is supplied, characterized in that a start signal logic for forming a coincident with the first image pulse pulse from a native signal f connected to the set input of a first flip-flop is that the output of the first flip-flop with an input of a first gate circuit, one with the video signal gleichfrequenter, synchronized clock pulse fn at whose second input _a 4. _A abuts, is connected and the output of the first gate circuit for count input of an up / Rückwärtszähler whose address outputs are connected to a first decoder for detecting the most significant address, with a second decoder for detecting the least significant address and the address inputs of a random access memory that the output signal of the first decoder to the Reset input of the first and the set input of a second flip-flop and the output signal of the second decoder leads to the reset input of the second flip-flop and to a discriminator, wherein the output of the second flip-flop is connected to an input of a second gate circuit whose second input is coupled to the clock pulse f-mwpA and whose output leads to the backward counting input of the front-to-back counter;
in that the first decoder communicates with the input for the operating state for the random access memory and that the video signal fy-rn-gn leads ^{to the} input input of the read-write memory and to an input of an OR circuit, the data output of the Read-write memory is connected to a second input of the OR circuit, the output of the OR circuit and the native signal f input signals of the discriminator form and the output of the discriminator and the output of the OR circuit with the inputs of a third, with coupled to the pixel counter, gate circuit are connected » For this 2 pages drawing 16. 2. 1984
Bie / Mr Buet