EP1943503A1

EP1943503A1 - Method and apparatus for detecting dirt in a moving fibre stream

Info

Publication number: EP1943503A1
Application number: EP06804843A
Authority: EP
Inventors: Hans Röösli
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2005-11-04
Filing date: 2006-10-31
Publication date: 2008-07-16
Also published as: WO2007051335A1

Abstract

A method for detecting dirt (S) is proposed in a fibre strand (FS) which is moved in its longitudinal direction (LR), for example a fibre ribbon, a roving or a yarn, in which primary light (PL) is radiated onto the fibre strand (FS), secondary light (SL) which is produced by reflections is detected by means of a line sensor (8) which is oriented transversely with respect to the running direction, line-shaped reproductions (Z1...Z12) of a section (A1...A12) of the fibre strand (FS) which is situated in each case in the detection region of the line sensor (8) are generated one after another at a predefinable clock frequency (TF) in a manner which is based on the detected secondary light (SL), and the line-shaped reproductions (Z1...Z12) are evaluated by means of an evaluation unit (10) for detecting dirt (S). The method is distinguished by the fact that the speed (G) of the fibre strand (FS) is detected continuously and is taken into consideration in the defining of the clock frequency (TF) and/or in the evaluation of the line-shaped reproductions (Z1...Z12). At the same time, a corresponding apparatus is proposed.

Description

METHOD AND DEVICE FOR DETECTING DIRT IN A MOVING FIBER CURRENT

The present invention relates to a method and a device for detecting dirt in a fiber stream moving in its longitudinal direction, for example a flock stream, a fiber sliver, a roving or a yarn, in which radiation is directed against the fiber stream and radiation emitted or passed on by the fiber stream , which is obtained within the detection range of a sensor, is detected by means of this sensor, wherein detected radiation, which was influenced by fibers, differs from detected radiation, which was influenced by dirt. The invention also relates to a textile machine which is provided with such a device and / or is prepared for cooperation with such a device.

In a preferred embodiment, primary light is irradiated against a fiber strand, in particular a sliver, and secondary light produced by reflections is detected by means of a line sensor oriented transversely to the direction of travel. Based on the detected secondary light, line-shaped images of a section of the fiber strand located in each case in the detection range of the line sensor can be generated one after the other and the line-shaped image can be evaluated by means of an evaluation unit for detecting dirt.

The term "dirt" as used herein includes the terms "contaminants", "foreign parts" and "nits" which are described in the Handbook of Textile Fabrication, "The Short Staple Spinning Band 1: General Technology" (Author: W. Klein) See pages 13-15 and page 25, in particular. The term "dirt" also includes the terms "trash" and "spurious particles" used in the following technical articles: "Trash Content of Carded and Combed Ring and Rotor Yarn" (Textil Praxis International, January / February 1994, pages 31 and 32); "New ways to achieve controlled and reproducible card sliver quality" (MeiLand Textile Reports, 7-8 / 2000, pages 587 to 592). From EP 0 643 294 a method and a device for detecting foreign substances in a thread is known. The thread is acted upon by the front and rear lights. The thread is imaged by means of a line sensor. The light reflected by the test material is to be measured and closed by a change in the reflected light to the presence of a foreign substance. A suitable line sensor has been described in CH-B-643060.

A length-specific evaluation is not possible with a device according to EP-A-643294 and also not required because the device is designed in particular for use in combination with a Gamreiniger. By means of the yarn cleaner, a contaminated with foreign matter piece of yarn is to be cut out immediately. It is not possible to determine the quantity of foreign substances nor their distribution in the longitudinal direction of the thread. It is also not possible to determine the size or the size distribution of the foreign substance particles.

The optical detection of dirt in a fiber strand has been the subject of many development projects for at least forty years. There is an extensive literature. In assessing this literature, it is important, or at least helpful, to consider the intended use of the device.

One important application is to detect dirt in a yarn or roving, i. E. H. in a compact structure having a twist. In this context, the goal is to detect any debris that appears on the surface of the fiber structure, as such dirt can affect the value of the product. Therefore, a piece of dirt containing debris should be cut out ("yarn cleaning" function) Many proposals in this category are based on EP-A-197763 (US 4739176) which describes a solution to the problem of diameter variation For example, DE-A-10359690 can be found in FIG.

According to another application, dirt is detected in a fibrous structure which is in the form of a thin pile or fleece. Such suggestions go to EP-A-226430, a practical example being found in EP-A-738792. With the fibers in this state, it is relatively easy to detect all debris, provided that the whole width of the pile (fleece) can be (quasi) continuously scanned. The individual dirt particles can also be removed individually. However, the effort involved is considerable and can not be justified for all applications.

Before a yarn or roving is formed, a nonwoven fabric must normally be converted into a so-called sliver. Also related to fiber. It has been suggested that it is first necessary to dissolve or spread the tape first to allow this (see, for example, GB-A-1211463). Meanwhile, it has been recognized that even without the spreading of the fibers measured values can be obtained on the sliver, see z. B ^ EP-A-402940 and EP-A-884408 and EP-A-1042545. However, such methods assume that the debris must appear on the surface of the belt, or that the light must penetrate the belt to detect any debris. The former assumption leads to a limited field of application for the method or the corresponding device. The second assumption leads to complex tactile devices.

The object of the present invention is therefore to provide a method, a device and a textile machine which avoid the disadvantages mentioned.

The object is achieved according to the independent claims.

The present invention is based on a new working approach. It will first be recognized that instantaneous mapping of a current fiber stream effectively equates to a sample. Although the image can be evaluated precisely for its information content, the results apply only to the part of the stream depicted. The mapping of portions of the stream may then be repeated to obtain a complete picture over the length. But this also requires a lot of effort. If, however, it is not necessary to intervene immediately on the basis of the measured values, For example, a data series or a series of measured values obtained from individual images can be evaluated according to statistical methods in order to obtain statements with ascertainable confidence limits.

Once the individual image is recognized as a "sample" for statistical evaluation, the need to fully illuminate a longitudinal section of the fiber stream is eliminated, and a sample will only provide partial information that must be supplemented or substantiated by further sampling Partial information can be obtained from a portion of a longitudinal section, thereby reducing the complexity requirements of the measurement system.

Now, by means of suitable electronics and / or optics, a test room on the current fiber stream, in particular on a sliver, are to be defined, without influencing the fibers themselves. The current content of the rehearsal room is examined and corresponding signals are generated, which can be evaluated. The examination is repeated at predetermined intervals to produce a series of sample values. This series of evaluations can itself be evaluated in order to allow statistically significant statements regarding the total fiber flow. Although it does not guarantee absolute safety, the method is capable of producing quality metrics that can be used operationally to reliably control machinery or fiber processing steps.

The method preferably operates by optical means, ie the sample space is defined by directing light or light-like radiation against the surface of the sliver and radiation returned or passed on from the current content of the sample room is detected and evaluated. The volume or the size of the sample room is determined by the brightness of the radiation source, the sensitivity of the detection means (sensor) and the optics. The sample compartment preferably comprises a three-dimensional flow part which includes a part of the flow surface. However, this current part preferably comprises only relatively few fiber layers in the vicinity of the abovementioned surface part, so that the fiber flow is by no means penetratingly examined. The fiber stream is preferably guided past the sensor in such a way that the sample space is always filled uniformly with fibers. In the case of a fiber strand, in particular a fiber band, this can be ensured by means of a slight deflection of the strand in the vicinity of the sensor. Compression of the fiber strand as proposed in EP-B-446808 and EP-B-1042545 is not required, but is not excluded by the present invention, provided that the compression does not result in a change in the technologically significant strand properties leads.

Each picture can be cell shaped. Cell-shaped images can then be strung together in the evaluation to give a two-dimensional image of a stream section. However, by using a sensor in the form of a camera, it is possible to directly produce a two-dimensional image, i. H. without having to produce this image by composing a plurality of line-shaped mappings. But even a two-dimensional image represents only one evaluable sample compared to the length of a fiber stream.

In order to enable the statistical evaluation, several images are generated and evaluated sequentially. For this purpose, a predetermined clock frequency for the creation of the images can be defined. The method according to the invention can then be further characterized in that the speed of a fiber strand is continuously recorded and taken into account in the specification of the clock frequency and / or in the evaluation of the images.

To compensate for mechanical tolerances of the line sensor of the Abtastmoduls, an uneven distribution of the primary light PL, the imperfection of a lens used and the sensitivity differences of the photodiodes 9, a method is proposed, wherein during operation for each photodiode 9 separately and continuously formed an average based on the reflected secondary light becomes. This makes it possible - seen over the width of the line sensor 8 - to create a representative background curve, this background curve (100%) then forms the basis for the evaluation of the reflected secondary light SL. Is z. B. the criterion for a If the debris causes the secondary light SL to drop by 40% (eg in the case of the debris T1), then the effective value, the so-called threshold value, is calculated individually for each photodiode on the basis of the background curve (= 100%).

By taking into account the speed of the fiber strand in the evaluation of the images is an exact statistical statement about the amount and distribution of dirt in the longitudinal course of the fiber strand possible. In this case, the size or the size distribution of the dirt particles can be determined. Furthermore, the consideration of the speed of the fiber strand in the specification of the clock frequency of an optimized number of images generated per length of content of the fiber strand. Since neither too little nor too many line-shaped images per longitudinal section are produced even if the speed of the fiber strand changes, reliable evaluation results result with justifiable evaluation effort.

The method is suitable for detecting dirt in a yarn, a roving or an open guided or in a compressed example by means of a funnel sliver. Dirt is the totality of unwanted particles in the fiber strand whose particle size - as a delimitation criterion to dust - is greater than 0.5 mm. Dirt occurs especially in the use of natural fibers, such as cotton, and includes mainly earth, shell parts and nits. Furthermore, the method is suitable for detecting foreign material, which has got into the fiber material, for example, during transport of the raw fibers.

In an advantageous embodiment of the method, it is provided that the clock frequency is set so that the imaged sections of the fiber strand adjoin each other in the longitudinal direction seamlessly. This results in the entirety of the images produced a gap-free, true-to-scale image of the fiber strand. This leads to a high statistical reliability of the evaluation results, whereby the effort for evaluation is limited. Alternatively it can be provided that the clock frequency is set so that overlap the imaged sections of the fiber strand in the longitudinal direction. This results in an at least partial redundancy of the images, which leads to an increase in the measurement accuracy. This arrangement is particularly advantageous when non-pulsed illumination is used.

Line-shaped images can be generated with a constant clock frequency, ie isochronously. Advantageously, the clock frequency can be determined as a function of the extent of the detection range of the line sensor in the longitudinal direction and the maximum speed of the fiber strand according to the formula TF = G _max / EL, where TF is the clock frequency, G _ma χ the maximum speed of the fiber strand and EL is the extension of the detection range of the line sensor in the longitudinal direction. EL is dependent on the width of the photosensitive area of the line sensor and a possibly used lens.

Preferably, the clock frequency is specified as a variable, the value of which is determined continuously as a function of the extent of the detection range of the line sensor in the longitudinal direction and the actual speed of the fiber strand so that a constant number of line-shaped images is generated per unit length of the fiber strand. If the mapped sections are to adjoin one another without gaps, the formula TF = G / EL can be used to determine the clock frequency, where TF is the clock frequency, G is the actual speed of the fiber strand and EL is the extension of the detection range of the line sensor in the longitudinal direction. Here, the clock frequency can be set so that overlap the imaged sections of the fiber strand in the longitudinal direction (LR) with a constant degree of coverage, this can be supplemented by a constant multiplier formula.

Preferably, it is provided that a plurality of successively generated line-shaped imaging fertilizers are combined to form a two-dimensional image, which is then evaluated for detecting dirt. As a result, the extent of dirt particles in the longitudinal and transverse directions can be determined exactly. In the evaluation of the two-dimensional image, pattern recognition is particularly preferably carried out, wherein shape, area, position, brightness values, brightness distributions, color values, color distributions and / or the sharpness of the edges of patterns occurring are used to detect dirt. In this case, a reliable qualitative and quantitative detection of dirt is possible.

In one development of the method, it is provided that detected dirt particles are classified into predefined classes on the basis of their properties, such as, for example, their shape, area or color. The predefined classes can be evaluated statistically. Thus, for example, the prevailing size of the dirt particles or the frequency of occurrence of nits can be determined.

Advantageously, pulsed primary light is radiated against the fiber strand, the pulses being synchronized with the generation of the line-shaped images. As a result, caused by the movement of the fiber strand blurring of the images produced can be reduced or prevented.

It is likewise advantageous if the intensity of the primary light is adapted continuously and automatically to the reflection properties of the fiber strand determined by the evaluation unit. This ensures that the line sensor is operated in an optimal range of its characteristic. This causes a high-contrast imaging of the fiber strand.

Furthermore, it can be provided that, in the production of the line-shaped images, in each case a section of the fiber strand is imaged whose extent transverse to the longitudinal direction is smaller than the width of the fiber strand. As a result, the evaluation results are independent of a change in the width of the fiber strand, since the edge regions of the fiber strand are not displayed.

The inventive device is designed in particular for carrying out the method described above. For this purpose, it can use a wired or wireless reception interface to receive the measurement signals of the actual Having speed of the fiber strand measuring speed sensor, wherein the receiving interface for forwarding the measurement signals to the clock generator to the clock generator and / or for forwarding the measurement signals to the evaluation unit is connected to the evaluation unit. In particular, the receiving interface may be a simple wire connection, a GSM interface, a Bluetooth interface, a Can-Link interface or a USB interface. The reception interface makes it possible to connect the device according to the invention to a speed sensor which is present anyway on many textile machines.

Advantageously, in this case it is provided that the clock generator is designed so that on the basis of the measurement signals forwarded to it an automatic determination of a said clock frequency takes place continuously, in which the fiber strand is imaged gap-free in its longitudinal direction. A gap-free mapping can be ensured by the continuous adaptation of the clock frequency at any speed of the fiber strand.

In this case, the clock generator can be designed so that a continuous and automatic determination of a said clock frequency is performed such that the imaged sections of the fiber strand in the longitudinal direction have a constant, independent of the actual speed coverage.

Alternatively, the clock generator can be designed such that an automatic determination of a said clock frequency takes place in such a way that the imaged sections of the fiber strand adjoin one another seamlessly in the longitudinal direction.

It is preferably provided that the evaluation unit is designed to join a plurality of successively generated cell-shaped images into a two-dimensional image and to evaluate the two-dimensional image so as to detect dirt. If the evaluation unit is designed to take into account the actual speed of the fiber strand during the assembly of a plurality of successively generated line-shaped images, a constant clock frequency can be predetermined.

Particularly preferably, the evaluation unit is designed for pattern recognition in the evaluation of the two-dimensional image, whereby the shape, area, position, brightness values, brightness distributions, color values, color distributions and / or the sharpness of the edges of occurring patterns for detecting dirt can be used.

Equally advantageously, it can be provided that the evaluation unit is designed for the classification of detected dirt particles on the basis of their properties in predefined classes. In this case, the evaluation unit can be designed to evaluate the distribution of the dirt particles to the individual classes.

Preferably, the evaluation unit comprises a microprocessor and preferably a memory module. In this way, the desired functions can be easily realized.

Advantageously, it is provided that a lighting control module is provided which controls the lighting arrangement such that pulsed primary light is radiated against the fiber strand, wherein the pulses are synchronized with the generation of the cell-shaped images.

Preferably, the lighting control module for the current and automatic adjustment of the strength of the primary light to the determined by the evaluation unit reflection properties of the fiber strand is formed. For this purpose, a closed loop may be formed, which comprises the line sensor, the evaluation unit, the lighting control module and the lighting arrangement. By continuously and automatically adjusting the illuminance to the reflective properties of the fiber material and the fact that the dirt is usually darker, the illuminance can be chosen so that the sensitivity range of the line sensor is optimally utilized. In an advantageous development of the invention, the illumination control module is assigned a D / A converter for receiving digital control and / or regulating signals for controlling and / or regulating the illumination arrangement.

Advantageously, the illumination arrangement comprises one or more light-emitting diodes. Light-emitting diodes are particularly suitable for illuminating the fiber strand, since they require comparatively little energy, have a defined color and, when switched on or off, change the light output with an extremely small time delay.

Preferably, the line sensor comprises a plurality of photodiodes arranged in a row. Such line sensors are inexpensive to manufacture, durable and work with high accuracy.

To improve the line-shaped images, each photodiode can be assigned a charge store and / or an amplifier circuit.

Serving the same purpose, the lens sensor can be preceded by a lens.

Advantageously, the lens has a diaphragm, which is preferably adjustable. As a result, sharper images can be generated and the amount of light incident on the line sensor can be regulated.

Preferably, the line sensor is associated with an A / D converter for converting the sensor signals. In this case, the sensor signals can be further processed directly digitally.

If a self-sufficient energy supply, for example with batteries or rechargeable batteries, is provided, the effort for external wiring of the device is reduced.

Advantageously, the device has a display unit, in particular a display, for displaying evaluation results and / or operating states of the device. is provided. Displayable evaluation results can be, for example, the quantity or the quality of the detected dirt. As an operating state can be displayed, for example, whether the device is on or off.

Preferred is a wireless or wired interface, in particular a GSM interface, a Bluetooth interface, a Can-Link interface, a USB interface or an interface according to another industry standard, for the transmission of outgoing data, in particular generated zeiienförmige mappings, generated two-dimensional images, operating states of the device, fault messages, evaluation results and / or control commands provided. This makes it possible to store or further process the images or images produced. Control commands can be transmitted, for example, to a machine or system control. So it is possible to automatically shut down a textile machine or a system when a predetermined amount of dirt occurring is exceeded. Likewise, the interface for the transmission of incoming data, in particular software, software updates and / or parameters for the evaluation, such as threshold values, be formed. Also, a remote control of the device is conceivable.

Preferably, the device has a substantially closed housing, wherein a window for exiting the Primärfichts and for the entry of the secondary light is provided. Openings in the housing are limited to a minimum, for example for the passage of cables. In this case, the device can also be used in harsh environmental conditions. The window is made of a transparent material, so that the primary light and the secondary light can pass undisturbed. Advantageous is the use of a sapphire crystal (Al ₂ O ₃ ) which prevents scratching by existing in the fiber material foreign material such as quartz sand

Advantageously, a guide device is provided for guiding the fiber strand. This ensures that the fiber strand is correctly positioned with respect to the line sensor. The guide device is preferably configured in a U-shaped cross-section. det, wherein the window is formed on the inside of the base of the U's. This results in a simple, compact and resistant design.

The guide means for guiding the fiber strand is preferably formed so that the fiber strand is guided on all sides. The guide device may be formed, for example, as a through hole on the housing of the device.

Particularly preferably, the guide device is designed so that the fiber strand can be brought into the guide device transversely to its longitudinal direction. Then it can be dispensed with a cutting of the fiber strand, if this is to be threaded.

In a particularly preferred embodiment, the device is designed as a self-sufficient module, which can be fastened to a textile machine by means of a detachable mechanical connection, for example with a clamping connection, a plug connection, a magnetic connection and / or a latching connection. The device can preferably be mounted or removed without tools on the textile machine. Autarkic means that the device is self-sufficient. This makes it possible to use the device alternately on different textile machines.

This is useful, for example, if several cards are fed with fiber material of the same source. In this case, it is often not necessary to detect the dirt in each of the produced card slivers. On the contrary, it is often sufficient to carry out random checks of the card slivers in order to check the function of the cleaning devices of the cards. Likewise, it is possible in a simple manner to retrofit existing textile machine with the module. This applies in particular if a speed sensor for detecting the speed of the fiber strand is present on the textile machine. In this case, only corresponding mechanical fastening means and means for transmitting the speed signal to the module are to be attached to the textile machine. To simplify the mounting or dismantling of the device in the textile machine, it may be provided that required wired electrical connections between the module and the textile machine can be produced by means of detachable electrical connection means.

In this case, the electrical connection means may comprise contacts arranged on the module and corresponding contacts arranged on the textile machine. These can be designed so that the contacts come into contact automatically when the device is attached to the textile machine.

A textile machine according to the invention has a device according to the invention for detecting dirt or is prepared for fastening a self-sufficient module.

Further advantages of the invention are described in the following exemplary embodiments. Show it:

Figure 1 shows an inventive device which is designed as a self-sufficient module;

FIG. 2 is a block diagram of a device according to the invention;

FIG. 3 shows a further exemplary embodiment of a block diagram of a device according to the invention;

4a, 4b and 4c, the generation of a two-dimensional image according to a method according to the invention and

FIGS. 5a, 5b and 5c show the generation of a two-dimensional image according to a modified method Figure 6 is a copy of Figure 2 of EP-A-446808.

Figure 7 is a copy of Figure 3a of EP-A-446808;

Figure 8 is a copy of Figure 3b of EP-A-446808;

Figure 9 is an isometric view of one embodiment of the present invention

Invention for use at the end of the card;

Figure 10 is a schematic diagram for explaining the operation of the embodiment according to Figure 9;

11 is a timing chart for explaining the evaluation of signals in an embodiment according to FIGS. 9 and 10; and FIG

FIG. 12 is a schematic diagram for explaining a modified embodiment;

FIG. 13 shows a diagram for the representation of a determined background curve for the individual photodiodes of a line sensor

The invention will be explained for the time being by means of concrete embodiments with a line sensor (FIGS. 1 to 5). Subsequently, the principles which can be seen therefrom are further developed on the basis of schematic representations (FIGS. 6 to 12).

FIG. 1 shows a device according to the invention which is designed as a self-sufficient module 1. is forming. It has a closed housing 2, in which a lighting arrangement 3 is arranged with a light emitting diode 4 for generating primary light PL. The primary light PL penetrates out of the housing 2 through a transparent window 5, whereby secondary light SL arises from reflections on the fiber strand FS, at least part of which passes back into the housing 2 through the window 5. The secondary light SL passes through an objective 6 and through an aperture 7 on the photosensitive side of the line sensor 8. Here, a multiplicity of photodiodes 9 are arranged, which convert appropriate secondary light SL into electrical signals SE. The electrical signals SE represent line-shaped images of a section of the fiber strand FS located in each case in the detection range of the line sensor 8. The line sensor 8 is mounted at a distance E to the lens 6 within the housing 2. With the help, z. B. a test pattern pattern presented to the window 5, the module 1 can be focused by changing the distance E in the production to obtain a picture with the best possible, or maximum contrast. Likewise, with the aid of a white test surface presented to window 5, a representative value for each photodiode 9 can be determined and stored in the evaluation unit. By using these values in the evaluation during operation, the existing tolerances and sensitivities between the individual photodiodes are taken into account. That is, it is - seen over the width of the line sensor 8 - created a representative background curve for the photodiode 9. This background curve then forms the basis for the evaluation of the reflected secondary light SL.

In order to compensate for the mechanical tolerances of the module 1, the uneven distribution of the primary light PL, the imperfection of the objective 6 and the sensitivity differences of the photodiodes 9, another method is also possible, wherein during the operation for each photodiode 9 (of e.g. a total of 64 photodiodes according to Fir. 13) is formed separately and continuously an average value. As a result, - seen over the width of the line sensor 8 - creates a representative background curve, such. B. is shown schematically in the diagram of FIG. 13. This background curve (100%) then forms the basis for the evaluation of the reflected secondary light SL. Is z. If, for example, the criterion for a dirt part causes the secondary light SL to drop by 40% (eg in the case of the dirt part T1), the effective value, the so-called threshold value, is calculated individually for each photodiode on the basis of the background curve (= 100%).

These signals SE or the line-shaped images are fed to an evaluation unit 10 for the purpose of evaluation. Evaluation results are sent to a display 11 and can be displayed there. Furthermore, the evaluation results can be sent to an interface 12 and from there to an external computer, for example for long-term analysis. time storage or for long-term evaluation. The generation of the line-shaped images by the line sensor 8 is carried out with a clock frequency TF ₁ which is predetermined by a clock generator 13. The clock frequency TF is also transmitted to a lighting control module 14. This supplies the lighting arrangement 3 with energy in such a way that the light-emitting diodes 4 emit pulsed primary light PL with a defined power. The illumination control module 14 also receives from the evaluation unit 10 a signal HS for brightness control.

To determine the clock frequency TF, the clock generator 13 evaluates the measurement signals MS of a sensor 27, which detects the speed of the fiber strand FS. The sensor 27 is part of a textile machine 100 to which the module 1 is fastened by means of releasable mechanical connection means 16. The detachable mechanical connection means 16 consist of elements 16a, which are arranged on the module 1, and of elements 16b, which are arranged on the textile machine 100. The elements 16a and 16b are designed to interact. They may for example be designed as permanent magnets.

The measurement signals MS of the sensor 27 are received by a receiving interface 15 of the module 1 via a wired connection. In this electrical connection releasable electrical connection means 17 are integrated, comprising arranged on the module 1 contacts 17a and arranged on the textile machine 100 contacts 17b. The contacts 17a and 17b are formed and arranged so that the connection of the sensor 27 to the receiving interface 15 is automatically established when the module 1 is attached to the textile machine 100. Alternatively, the connection could be made via a manually attachable cable. The received measurement signals MS are transmitted to the clock generator 13 so that it can determine and preset the clock frequency TF as a function of the speed of the fiber strand FS. Likewise, the measurement signals MS are transmitted to the evaluation unit 10, so that the speed of the fiber strand FS can also be taken into account in the evaluation of the line-shaped images. On the housing 2, a guide device 20 for guiding the fiber strand FS is formed. This has a U-shaped cross-section, wherein the window 5 is arranged at the base of the U and the fiber strand FS is guided by the legs of the U and its base. The fiber strand FS can be laterally switched on or swung over the open side of the U's. The width B of the fiber strand FS is determined by the distance between the legs of the U and independent of the cross section of the fiber strand FS. The detection width of the line sensor 8, however, is determined by the width of the window 5, the lens 6 and the length of the photosensitive region of the sensor 8 and - regardless of the thickness of the fiber strand FS - less than its width B. Therefore, a change in the cross section of the fiber strand FS does not affect the images produced or the evaluation thereof.

Furthermore, a power supply 18 is provided in the housing 2, which comprises a self-sufficient energy source, namely a battery pack 19. Alternatively, the power can be supplied from the textile machine 100.

FIG. 2 shows a detailed block diagram of a device according to the invention. The line sensor 8 has a multiplicity of photodiodes 9, of which eight are shown by way of example. Usually, at least 32, preferably at least 64 and more preferably 128 photodiodes 9 are provided. Each photodiode 9 is associated with a charge storage 21 and an amplifier circuit 22. The analog signal SE 'of the line sensor 8 is fed to an A / D converter 23 and converted by the latter into a digital signal SE.

The digital signal SE is fed to the evaluation unit 10, which has a microprocessor 24 and a memory module 25 connected thereto. The microprocessor 24 determines from the digital signal SE a target value for the brightness of the primary light PL. This setpoint is contained in the digital signal HS, which is transmitted from the microprocessor 24 to a D / A converter 26 and from there as an analog signal HS 'to a lighting control module 14. The lighting control mode dul 14 in turn regulates the light output of the LEDs 4 of the lighting device 3 based on the signal HS '. For this purpose, it has a suitable power electronics.

The measurement signals MS of the speed sensor, not shown, are passed through the receiving interface 15 to the microprocessor 24 and to the clock generator 13. The clock generator 13 generates a clock frequency TF, which for the timing of the Zeiiensensorsδ, the A / D converter 23, the lighting control module 14 and. of the D / A converter 26 is forwarded.

In the described embodiment, the brightness of the LEDs 4 is determined by the evaluation unit 10 and the pulsation of the LEDs by the clock generator 13. Alternatively, however, both parameters could be specified by the evaluation unit 10. In this case, it is not absolutely necessary to transmit the clock frequency TF of the clock generator 13 to the lighting control module 11.

The microprocessor 24 is still in communication with the interface 12 and the display 11th

In order to fully utilize the input voltage range of the A / D converter 23 for maximum accuracy (resolution), the signal of the photodiodes may be amplified via an amplifier circuit 22.

FIG. 3 shows a modified block diagram of a device according to the invention. The function of the clock generator 13 is in this case integrated into the microprocessor 24. Furthermore, the functions of the receiving interface 15 for receiving the measuring signals MS of the speed sensor and the interface 12 for receiving incoming data and for sending outgoing data are combined in one unit.

Figures 4a, 4b and 4c illustrate the inventive method for detecting dirt in a moving fiber strand. FIG. 4a shows a fiber strand FS which is moved in its longitudinal direction LR at the speed G relative to a line sensor. The fiber strand FS has a dirt particle S. The detection range of the line sensor is by its longitudinal extent EL and described by its transverse extension EQ. Each line-shaped image generated by the line sensor therefore represents a section A of the fiber strand FS ₁ , each section A being the same length and the same width. The width of the sections A corresponds to the transverse extent EQ of the detection range of the line sensor. If, as assumed in FIG. 4a, the generation of a line-shaped image takes place with a sufficiently short exposure time, then the longitudinal extension of the sections A corresponds to the longitudinal extent EL of the detection range of the line sensor. The longitudinal extent of the sections A can then be regarded as independent of the speed G of the fiber strand FS.

In the present example, line-shaped images of the fiber strand FS are generated in succession, the underlying cycle frequency being selected such that the imaged sections A1 to A6 adjoin one another without gaps. In this case, it is not necessary for the speed G of the fiber strand FS to remain constant, since the clock frequency is specified taking account of the speed G.

FIG. 4b shows the line-shaped images Z1 to Z6, which each represent one of the sections A1 to A6. Each line-shaped image Z1 to Z6 comprises a plurality of linearly arranged pixels BP. For each of the pixels BP, a brightness and / or color value is determined and recorded. The cell-shaped images Z1 to Z6 are transmitted to the evaluation unit and evaluated there. For this purpose, these are combined to form a two-dimensional image ZDB shown in FIG. 4c. Since the imaged sections A1 to A6 each adjoin one another without gaps, the image ZDB can be generated in a simple manner by juxtaposing the line-shaped images Z1 to Z6. The image ZDB is a true-to-scale image of the detected section of the fiber strand FS. The two-dimensional image ZDB can now be evaluated by means of pattern recognition. In particular, a length-related evaluation is possible.

Figures 5a, 5b and 5c show a modification of the method, wherein the clock frequency as a function of the speed G of the fiber strand FS so determined is that each adjacent sections, which are represented by cellular images overlap with a constant degree of coverage in the amount of 50%. Under otherwise unchanged conditions, line-shaped images Z1 to 2 12 are now formed when imaging the same longitudinal section of the fiber strand FS 12. The overlapping images Z1 to Z12 detect each region of the fiber strand FS twice. As a result, accidental measurement errors can be at least reduced in their effect.

However, the line-shaped mappings Z1 to Z12 can not simply be lined up in the generation of the two-dimensional image ZDB ', since in this case a distortion would result. However, the detection range of the line sensor and the speed G of the fiber strand FS is known. Therefore, a true-to-scale image ZDB ', which is shown in Figure 5c, can be used. are calculated from the line-shaped maps Z1 to Z12. The two-dimensional image ZDB 'has six lines and can be evaluated in the usual way, whereby a length-specific evaluation is readily possible.

As can be seen from FIGS. 4a to 4c and FIGS. 5a to 5c, the pixels have different brightness values for the region of the detected dirt particle. In other words, the edge regions of the dirt particle, which are partly below the surface of the fiber stream, have a higher brightness value than the center of the dirt particle protruding from the fiber strand. These differences can z. B. be used to carry out the statistical evaluation. That is to say, as soon as it is determined on the basis of the detected brightness value that it is a dirt particle projecting from the fiber mass, the pixels with a higher brightness value detected around the center of the detected dirt particle are also detected in order to detect the size of the dirt particle which is responsible for a statistical evaluation of the dirt particle is used. This evaluation, or detection and assignment of the dirt particle can be controlled by the software. Such an evaluation of the size of the dirt particles is particularly advantageous if - as will be described below - the dirt particles or interfering particles are assigned to different types or classes. FIG. 6 shows the discharge section 120 of a carding machine (a machine without a fiber ribbon) and the band depositing station 121 downstream of this outlet with a can 121 'for receiving the sliver in turns. According to EP-A-446808, a measuring point with a measuring probe 101 is provided on the tape tray 121. The measuring probe 101 according to the EP document is suitable for obtaining color measurement values on the passing fiber sliver FS (see FIG. 7).

Further, according to the prior art in this EP publication, the measuring probe is arranged at a point where "process-inherent compression" takes place, where the sliver passes through a funnel 122. The funnel neck 123 (FIG In order for the continuous sliver FS to have a width sufficient for color measurement, the funnel neck 123 has the shape of a very flat rectangle with rounded corners as shown in Figure 8. The wide side 124 of the funnel neck 123 facing the probe consists of a translucent material, the opposite side 125 carries against the sliver turned a replaceable surface in the appropriate background color on the storage hopper follows in the direction of tape travel, a pair of transport rollers 126th

Although "process-aware compression" according to EP-A-446808 is not necessary for the realization of the present invention, it is also not excluded, so that the arrangement according to figures 6 to 8 could be adapted for an embodiment of the present invention.

In the preferred arrangement, however, the measuring point is not provided on the tape storage, but directly after the card discharge, for example at the point X (FIG. 6), after completion of the band formation. A suitable embodiment of the measuring device is shown in FIG.

FIG. 9 shows a housing 2 with a front wall 50 and walls 2OA, 2OB protruding therefrom. The wall 50 forms a curved guide surface for a sliver, z. B. for the band FS (Fig. 7). In this wall 50, a translucent window 5 is provided and the housing 2 includes one for the realization of the invention suitable electronics and optics (not visible in FIG. 9, a suitable arrangement has been described in connection with FIG. 1). The conditions at the window 5 will now be explained in greater detail, with reference to the schematic diagram in FIG. 10, where the guide surfaces formed by the walls 20A, 20B and the window 5 are shown schematically. In Figure 10 it is assumed that between the walls 2OA, 2OB the space in front of the surface 50 is continuously filled with fibers of the current sliver FS, in this figure, only the part of the band FS in the vicinity of the wall 50 and the Window 5 is indicated schematically. However, it is assumed that "trash particles" are moved under these fibers, wherein in the process state, which is shown in FIG. 10, three such particles T1, T2, and T3 are located in front of the window 5,

As already mentioned, an electronics / optics is provided in the housing 2, which is indicated in FIG. 10 as a unit with the reference symbol E. The unit E generates a primary radiation, preferably light, which is directed through the window 5 onto the fiber ribbon FS. Excited by the primary radiation, the fibers generate secondary radiation which at least partially flows back through the window 5 and is received in the housing 2 by a suitable receiving means in the unit E. The unit E generates corresponding output signals which can be evaluated.

The interaction between the radiation and the particles T1, T2, T3 can be seen from the diagram of FIG. This diagram shows the level of the output signal from unit E over time. The secondary radiation generated by the fibers excited in the unit E, although variable, but always relatively high signal level P. In the case of a Trashpartikels, such as the particle T1, which appears on the belt surface at the window 5 or in the vicinity of this surface, falls Signal level strong as long as the particle T1 effectively shields the fibers in the band of the primary radiation, because the particle T1 generates significantly less secondary radiation, as the fibers.

However, the secondary radiation received by the unit E is not only from the fibers present on the belt surface (directly at the window 5). Even fibers in deeper layers generate secondary radiation, which normally exerts an influence on the signal level at the output of the unit E. However, the influence of the fibers in a deeper layer is disturbed by a trash particle such as the particle T2, because the amount of secondary radiation from the deeper layers, taken together in the signal level P, is reduced as long as the particle T2 of the unit E opposes. However, the effect of the particle T2 on the signal level P is significantly attenuated compared to the effect of the particle T1, because the fibers between the particle T2 and the window 5 generates a secondary radiation which keeps the signal level high.

However, the sensitivity of the unit E is chosen such that fibers in even deeper layers, further away from the window 5, can exert no discernible effect on the signal level P. The system is thus tuned such that the unit E is unable to detect secondary radiation from parts of the sliver further away from the window 5, then not; when the primary radiation can penetrate into these deeper layers. Therefore, a trash particle, such as the particle T3 trapped in these deeper fiber layers, can not exert a noticeable effect on the signal level P. The particle T3 even possibly exerts a certain effect on the detected secondary radiation, which at most leads to a decrease in the signal level P. However, this change in the output of unit E falls within the "bandwidth" (tolerance), which is also affected by other factors in the system, so that the effects of these various factors can not be reliably differentiated.

The "light collecting space" of the unit E thus extends only to a depth t from the front wall 50 (from the window 5) and by no means comprises the entire thickness of the sliver, which is not even completely shown in the sketch according to FIG In one embodiment of the present invention, the depth t can be kept small, for example in the range of 0.1 to 0.5 mm. The function of the tape guiding device, which consists of the surface 50 and the side walls 20A, 20B, is therefore to provide for this in that, for a given belt tension, the space which can be allocated to the light collecting space of the unit E is always and as evenly as possible filled with fibers of the moving belt. As already explained, compression of the belt for this purpose is not required; kung, for example by means of a slight curvature of the surface 50, but quite appropriate.

The amount of material which exerts a momentary influence on the signal level P, however, is determined not only by the distance t from the window 5, but also by the size of the two-dimensional detection range of the sensor, namely its extension both in the direction of movement of the sliver and in the direction perpendicular to it. The detection range is determined in the transverse direction by the width W of the window 5, and the width W is considerably smaller than the distance S between see the guide surfaces 2OA, 2OB. In the direction of movement of the sliver, the size of the detection area is determined by the design of the unit E rather than by the design of the window 5.

One can therefore speak of a "rehearsal room" which lies in front of the window and is defined on the one hand by the effective coverage area of the unit E and on the other by the depth t The current content (fibers, particles, etc.) of this rehearsal room can be considered as a "sample", which is to be examined by means of the unit E. The sample is, for example, less than 5% of the fiber material (from the longitudinal section of the fiber sliver), which in the moment of the unit E is opposite.

The examples presented assume the determination of the number of so-called trash particles. It is also possible to determine the number of nits, for example according to the principles explained in the article "Automation in fiber testing" (Textile Practice International, January 1991, pages 15 to 17).

Statistical evaluation of the data:

The general principles of the statistical evaluation of data on spurious particles in elongated textile products, such as tapes, rovings and yarns are well known to those skilled in the textile laboratory (offline) and need not be repeated here. Basically, a determined number of interfering particles is directly or indirectly in This amount of fiber can be determined in units of weight (eg per g) or in units of length of the product being examined (eg per m or km). The spurious particles themselves can be assigned to various types, for example, nits, shawls, trash particles, dust, and the particles can be assigned to different classes depending on their sizes within these types. Examples of the practical application of these principles are, for. As in Textile Practice International, January / February 1994, pages 31 and 32 (Article "Trash content of carded and combed ring and rotor yarn") and / or Melliand Textilberichte, 7-8 / 2000, pages 587 to 592 (technical article "New Ways to achieve controlled and reproducible card sliver quality ").

In an application in the context of the present invention, it is possible by the compilation of the individual images to effectively obtain an image of a fiber ribbon piece of predetermined length (eg of one meter), the number ("frequency") of predeterminable types of spurious particles in to determine this sliver piece, and to repeat the procedure for the subsequent sliver piece, so that the content of the "rehearsal room" (quasi) is checked continuously. However, since only a fraction of the fibers in the product (eg sliver) flow through the sample room and are analyzed, the readings are effectively results for a sample series. The measured values will therefore have a detectable scatter. However, such measured value series can be further investigated according to the statistical method, for example by determining the frequency distribution with corresponding derivations with respect to characteristic characteristics of this distribution. In the presence of a normal (Gaussian) distribution (frequency distribution in the form of a bell-shaped curve), z. For example, the mean value of the distribution can be readily determined and taken as a characteristic characteristic of the distribution. When determining a secular trend in this characteristic and / or when determining a change in the distribution and / or when (repeatedly) determining "outliers" (values outside certain predetermined confidence limits, which can be determined depending on the determined frequency distribution ), the result of the evaluation should be specifically reported or an alarm triggered and / or the fiber processing to be stopped.

From this chapter it follows that the reliability of the results increases with the repetition of the evaluation or with the increase of the number of considered "samples." The display can be designed in such a way that both the valid characteristic values and the parameters for the trustworthiness of these values are displayed.

The invention therefore provides a kind of automated sample analysis.

In principle, the sample may include all the fibers that are in front of the sensor at the time of making an image, i. H. it may comprise all fibers which are located in a predeterminable longitudinal section of the fiber stream. This mode of operation is possible where the radiation is able to "shine through" the fiber stream and the sensor is able to react on the entire contents of the longitudinal section, but this operation is relatively expensive and not required to be reliable To achieve results.

The sample may therefore comprise only a portion of the fibers located in a longitudinal section of the fiber stream. This portion of the fibers may comprise only those fibers which are located on the surface or on a part of the surface of a fiber structure, for example in the detection of foreign fibers in a compact structure such as a roving or a yarn. In the preferred variant, where the sample contains only a fraction of the fibers located in a predeterminable longitudinal section of a fiber strand, this part of the fibers comprises both those fibers which are in the detection range of the sensor at the surface of the fiber strand also fibers within this surface.

The now proposed method of operation can be used in all stages of processing of fibers in the spinning line, ie also in series of measurements, which were obtained from a flock stream or were obtained from a roving or a yarn. The now proposed method of working is not useful if immediately on the detection of interfering particles or foreign material should be reacted, z. B. in the yarn cleaning. The statistical analysis of the sample analysis can not provide instantaneous values that can be used as a reliable basis for immediate control intervention. The new method is especially useful where the fiber stream to be examined has a relatively high content of interfering particles, eg. B. after the card until the formation of a coil in the Kämmereivorbereitung. The sample analysis is also particularly useful if the content of the samples can be accepted as representative of the total content of the fiber stream. Where z. If, for example, systematic effects lead to differences between the content of interfering particles in the "rehearsal room" and other parts of the flow, either these effects must be taken into account in the evaluation or the reliability of the results must be reduced.

The instantaneous velocity of the fiber stream is important for various aspects of a complete evaluation - examples: for (a) the assignment of the determined spurious particles to respective fiber stream parts (b) the determination of the actual size of a particular particle (c) the compilation of the images to create an image the passing fiber stream or predetermined longitudinal sections thereof. The use of a signal provided by the machine in this regard is a useful but not optimal compromise. It would be better to determine the instantaneous running speed of the fiber flow within the test apparatus itself. The principles of a suitable solution will be explained for the time being with reference to a schematic representation in FIG.

The embodiment according to FIG. 12, like the embodiment according to FIG. 9, comprises a housing 2 with a curved front wall 50 and sliver guide walls 20A, 20B (only wall 2OA visible in FIG. 12). However, the housing 2 has in FIG. 12 two chambers 52 and 54, each with a window 5A, 5B in the front wall 50 and one sensor unit E1 and E2 respectively. The running direction of the sliver is indicated by the arrow L. The two units E1, E2 each define a detection area and these areas have a known, mutual distance A in the direction of L on. This distance may be between planes perpendicular to the respective detection. be defined, provided that the selected levels each have the same relationship to the respective coverage area, for example, in each case the median plane of the area. The unit E1 therefore first creates a map ABB1 of a certain sliver section at a time Z1, where this section is located in the detection area of the unit E1. Shortly thereafter, at time Z2, unit E2 creates a map ABB2 of the same sliver section as this section is within the coverage of that unit.

Each unit E1, E2 delivers its respective map ABB1, ABB2 to a signal processor P, which is provided with a timing device Z or cooperates, so that the time Z1 or Z2 of the creation of the respective image is fixed. By analyzing the respective waveform of these two images, the processor is able to recognize that they are from the same sliver section. The time interval between the presence of this portion in the detection range of the unit E1 and the presence of the portion in the detection range of the unit E2 can therefore be determined, wherein the instantaneous speed of the sliver in the device 2 can be derived from the known distance A.

Although the embodiment according to FIG. 12 is conceivable and advantageous for the explanation of the principle, it does not represent the preferred solution because it requires an enlargement and complication of the construction of the device. In practice, it is possible to provide the units E1, E2 next to each other in a single chamber and to assign them to a common window 5, wherein their detection ranges nevertheless have a predetermined distance A. It would even be conceivable to provide only a single unit E with two detection areas having a mutual distance A.

The use of multiple detection areas or units has the additional advantage that additional information relating to this section can be obtained from the analysis of the different images of the same sliver section. The assignment of the different pictures to each other on the basis of Processor noted similarities in the structure of the images can therefore be followed by further investigations of the mapping theorem.

The invention therefore provides, in all variants, a method for detecting dirt in a fiber stream moving in its longitudinal direction, in particular a sliver, in which radiation is directed against the fiber stream and radiation emitted or passed on by the fiber stream, which is obtained within the detection range of a sensor , is detected by this sensor, wherein detected radiation, which was influenced by fibers, differs from detected radiation, which was influenced by dirt. Based on the detected radiation, at least one image of a fiber stream portion may be generated and evaluated by an evaluation unit to determine whether differences in the detected radiation within the image suggest the presence of debris within the fiber stream portion.

In a variant, a second detection area is defined as viewed in the direction of movement of the fiber stream, whereby radiation occurring within the second detection area is also detected and used to form a respective image. An evaluation unit can be provided which compares images which originate from the respective detection areas with one another in order to detect similarities and thus to associate the respective images with the same fiber flow section. If the said detection areas have a previously known respective distance in the direction of movement of the fiber stream, the current velocity of the stream can be inferred when recognizing similarities in two images which were ever created at a known time. This information can then be used to further analyze the data, for example, to compile the images of a series to form a larger image.

To determine the speed of the fiber flow, the use of other known non-contact measuring systems is also conceivable. This z. B. optical systems that operate on the spatial filter principle, with optical-electronic sensors are used, which image movements in speed proportional Convert output signal frequencies. On the other hand, it is also possible to use measuring systems which work according to the Doppler effect, whereby the change in the measured frequency of waves of every type is detected during scanning of the surface of the fiber stream. Such measuring systems can be integrated within the housing with the dirt detection unit. However, it would also be conceivable to have a separate arrangement of the described measuring systems for detecting the speed in front of or behind the sensor for dirt detection.

The present invention is not limited to the illustrated and described embodiment. There are modifications within the scope of the claims at any time.

Claims

claims

1. A method for detecting dirt in a moving in its longitudinal direction of the fiber stream, in particular a sliver in the radiation directed against the Faser- ström and emitted or forwarded by the fiber flow or forwarded radiation, which is obtained within the detection range of a sensor, is detected by means of this sensor in which detected radiation, which was influenced by fibers, differs from detected radiation, which was influenced by dirt, characterized in that based on detected radiation, a series of images of the respectively located in the detection area fiber stream part is generated and the images are evaluated, in order to determine whether differences in the detected radiation within an image can indicate the presence of dirt within the corresponding fiber stream part, and that, based on this evaluation, a series of measured values is generated and statistically evaluated.

2. The method according to claim 1, characterized in that the fiber flow part comprises only a part of the fibers, which are present in a predeterminable longitudinal portion of the fiber stream.

3. The method according to claim 2, characterized in that the fiber stream part in each case comprises both fibers which are in the detection range of the sensor in the strand surface, as well as fibers which lie within this surface.

4. The method according to claim 2 or 3, characterized in that the fiber flow part 0.5 to 5%, for example, 1 to 2%, which represents the sensor fiber facing at the time of creating the image.

5. The method according to any one of claims 1 to 4, characterized in that the sensor has a cellular detection area, which is arranged transversely to the direction of movement of the fiber strand.

6. The method according to any one of claims 1 to 4, characterized in that the sensor comprises a camera.

7. The method according to any one of the preceding claims, characterized in that the frequency distribution of the measured values is examined in the statistical evaluation.

8. Method according to one of the preceding claims, characterized in that, viewed in the direction of movement of the fiber stream, a second detection area is defined, wherein radiation occurring within the second detection area is also detected and used to form a series of images.

9. The method according to claim 8, characterized in that an evaluation unit is provided, which images that originate from the respective detection areas, compared with each other to detect similarities and thus assign the respective figures to the same fiber flow part.

10. The method according to claim 9, characterized in that the detection areas have a previously known respective distance in the direction of movement of the Faser stream, so that when recognizing similarities in two images, which were ever created at a known time, on the instantaneous speed of the electricity can be closed.

11. The method according to claim 10, characterized in that the determined speed then for further analysis of the data, for example for

Composing the pictures to form a larger picture, used becomes.

12. A device for detecting dirt in a moving in its longitudinal direction fiber stream, in particular a sliver, with a radiation generator for directing radiation against the fiber stream, at least one sensor for detecting emitted from the fiber stream or forwarded radiation, which within the detection range of this sensor and generating corresponding output signals, characterized by a signal processing device, which can generate a series of images of each located in the detection range fiber stream portion based on the detected radiation, and an evaluation unit which is programmed so that it can determine whether differences in the Within the figure, the detected radiation within an image can be deduced from the presence of dirt within the corresponding fiber flow part in order to generate corresponding measured values and can statistically examine the measured value series.

13. The device according to claim 12, characterized in that the Strahlungser- generator and / or the sensor are tuned such that the fiber flow part comprises only a portion of the fibers, which are present in a predeterminable longitudinal portion of the fiber stream.

14. The device according to claim 13, characterized in that the Strahlungser- generator and / or the sensor are tuned such that said fiber stream part comprises both fibers which are in the detection area in the strand surface, as well as fibers which lie within this surface.

15. The device according to claim 13 or 14, characterized in that a Faser current guidance device is provided to guide the current to the sensor such that a sample space in front of the sensor as continuously as possible and is evenly filled with fibers of the stream.

16. Device according to one of claims 13 to 15, characterized in that the radiation generator and / or the sensor are tuned such that, in operation, the test room represents 0.5 to 5% of the fiber facing the sensor fiber mass.

17. Device according to one of claims 12 to 16, characterized in that the sensor has a line-shaped detection area, which is arranged transversely to the direction of movement of the fiber stream.

18. The device according to claim any one of claims 12 to 16, characterized in that the sensor comprises a camera.

19. Device according to one of the preceding claims 12 to 18, characterized in that the evaluation unit is programmed such that the frequency distribution of the measured values can be determined in the statistical evaluation.

20. Device according to one of the preceding claims 12 to 19, character- ized in that viewed in the direction of movement of the fiber stream, a second detection area is defined, wherein radiation occurring within the second detection area, also detected and to form a respective series of images is used.

21. The device according to claim 20, characterized in that an evaluation unit is provided, which images that originate from the respective detection areas, can compare with each other to recognize similarities and thus assign the respective images the same fiber stream part.

22. The device according to claim 21, characterized in that the detection areas have a known distance in the direction of movement of the fiber stream, so that in the detection of similarities in two images, the have ever been created at a known time on the current speed of the current can be concluded.

23. Device according to claim 22, characterized in that the evaluation unit is programmed such that the determined speed is used for further analysis of the data, for example for assembling the images of a row to form a larger image.

24. A method for aligning the sensor (8) according to claim 17, wherein the sensor (8) is provided with a plurality of adjacent photodiodes (9), characterized in that based on the reflected secondary light (SL) during operation for each photodiode (9) separately and continuously an average. (IQQ%.) With which ^■ == over the width (EQ) of the line sensor (8) seen - a representative background curve for the photodiodes (9) of the sensor is created, which is based on the evaluation unit (10) is placed.

25. Method, in particular a method according to claim 1, for detecting dirt (S) in a fiber strand (FS) moved in its longitudinal direction (LR), for example a sliver, a roving or a yarn, in which primary light (PL ) is irradiated against the fiber strand (FS), formed by reflections secondary light (SL) is detected by a transversely aligned to the direction of line sensor (8), based on the detected secondary light (SL) with a predetermined clock frequency (TF) successively line-shaped mappings (Z1 ... Z12) of a section (A1... A12) of the fiber strand (FS) which is in each case in the detection range of the line sensor (8) and the cell-shaped images (Z1... Z12) are generated by means of an evaluation unit (10). be evaluated for the detection of dirt (S), characterized in that the speed (G) of the fiber strand (FS) continuously detected and in the specification of the clock frequency (TF) and / or in the evaluation the line-shaped images (Z1 ... Z12) are taken into account.

26. The method according to claim 25, characterized in that the clock frequency (TF) is set so that the imaged sections (A1 ... A12) of the fiber strand (FS) in the longitudinal direction (LR) adjoin each other seamlessly.

27. The method according to claim 26, characterized in that the clock frequency (TF) is set so that overlap the imaged sections (A1 ... A12) of the fiber strand (FS) in the longitudinal direction (LR).

28. The method according to claim 26 or 27, characterized in that the clock frequency (TF) is given as a constant whose value in dependence on the extent of the detection range of the line sensor (8) in the longitudinal direction (LR) and the maximum speed provided ( G _max ) of the fiber strand (FS) is determined. - - -

29. The method according to claim 26 or 27, characterized in that the value of the clock frequency (TF) in dependence on the extension (EL) of the detection range of the line sensor (8) in the longitudinal direction (LR) and the actual speed (G) of the fiber strand continuously so it is determined that a constant number of line-shaped images (ZL..Z12) is generated per unit length of the fiber strand (FS).

30. The method according to claim 29, characterized in that the clock frequency (TF) is set so that overlap the imaged sections (A1 ... A12) of the fiber strand (FS) in the longitudinal direction (LR) with a constant degree of coverage.

31. The method according to any one of claims 25 to 30, characterized in that a plurality of successively generated line-shaped images (Z1 ... Z12) are combined to form a two-dimensional image (ZDB), which is then evaluated for detecting dirt (S) ,

32. A method according to claim 31, characterized in that during the evaluation of the two-dimensional image (ZDB) a pattern recognition is carried out, wherein form, area, position, brightness values, brightness distributions, color values, color distributions and / or the sharpness of the edges of occurring patterns for Detection of dirt (S) are used.

33. The method according to any one of claims 25 to 32, characterized in that detected dirt particles (S) are classified by their properties in predefined classes.

34. The method according to claim 33, characterized in that the distribution of the dirt particles (S) is evaluated on the individual classes.

35. The method according to any one of claims 25 to 34, characterized in that pulsed primary light (PL) is irradiated against the fiber strand (FS), wherein the

Pulse with the generation of the line-shaped images (Z1 ... Z12) are synchronized.

36. The method according to any one of claims 25 to 35, characterized in that the strength of the primary light (PL) continuously and automatically to the by the evaluation unit (10) determined reflection properties of the fiber strand (FS) is adjusted.

37. The method according to any one of claims 25 to 36, characterized in that in the generation of the line-shaped images (Z1 ... Z12) each have a section

(A1 ... A12) of the fiber strand (FS) is mapped whose extension (EQ) transverse to the longitudinal direction (LR) is less than the width (B) of the fiber strand (FS).

38. Device, in particular a device according to claim 12, for detecting dirt (S) in a fiber strand moved in its longitudinal direction (LR)

(FS), for example a sliver, a roving or a yarn, in particular for carrying out the method according to one of claims 1 to 13, with a ner lighting arrangement (3) for irradiating the fiber strand with primary light (PL), with a transversely to the longitudinal direction (LR) of the fiber strand arranged line sensor (8) for detecting reflected by secondary reflections (SL) and for the sequential generation of on the detected secondary light ( SL) 5 based cell-shaped images (Z 1 ... Z12) of each located in the detection range of the line sensor (8) section (A1 ... A12) of the fiber strand, with a clock generator (13) for specifying a clock frequency (TF) for the generation of the cell-shaped images (ZL..Z12) and with an evaluation unit (10) for evaluating the cell-shaped images (Z1 ... Z12) so as to detect dirt (S) 0, characterized in that it has a wired or wireless reception interface (15), in particular a GSM interface, a Bluetooth interface, a Can-Link interface or a USB interface, for receiving the measurement signals (MS) of the t The speed interface (15) for forwarding the measuring signals (MS) to the clock generator (13) with the latter and / or for forwarding the measuring signals (MS) to the Evaluation unit (10) is connected to this.

39. The apparatus according to claim 38, characterized in that the clock generator 0 tor (13) is formed so that on the basis of the forwarded measuring signals (MS) continuously an automatic determination of a variable clock frequency (TF), in which the fiber strand (FS ) is shown without gaps in its longitudinal direction (LR).

40. Apparatus according to claim 38, characterized in that the clock generator (13) is designed so that continuously an automatic determination of a variable clock frequency (TF) takes place such that the imaged sections (A1 ... A12) of the fiber strand in the longitudinal direction (LR) have a constant, independent of the actual speed (G) degree of coverage. iθ

41. Apparatus according to claim 38, characterized in that the clock generator (13) is designed so that a continuous and automatic determination a variable clock frequency (TF) is such that the imaged sections (A1 ... A12) of the fiber strand in the longitudinal direction (LR) adjoin each other seamlessly, independently of the actual speed.

5 42. Device according to one of claims 38 to 41, characterized in that the evaluation unit (10) for assembling a plurality of successively generated line-shaped images (Z1 ... Z12) to a two-dimensional image (ZDB) and for the evaluation of the two-dimensional image (ZDB ), so as to detect dirt (S) is formed. 0

43. Apparatus according to claim 42, characterized in that the evaluation unit (10) is designed to take account of the actual speed (G) of the fiber strand during the assembly of a plurality of successively generated line-shaped images (Z1 ... Z12). 5

44. Device according to one of claims 42 or 43, characterized in that the evaluation unit (10) for pattern recognition in the evaluation of the two-dimensional image (ZDB) is formed, wherein shape, area, position, brightness values, brightness distributions, color values, color distributions and or the sharpness of the edges of occurring patterns for detecting dirt (S) are approachable.

45. Device according to one of claims 38 to 44, characterized in that the evaluation unit (10) is designed for the classification of detected dirt particles (S) based on 5 of their properties in predefined classes.

46. Apparatus according to claim 45, characterized in that the evaluation unit (10) is designed to evaluate the distribution of the dirt particles (S) to the individual classes. iθ

47. Device according to one of claims 38 to 46, characterized in that the evaluation unit (10) has a microprocessor (24) and preferably a Memory module (25) includes.

48. Device according to one of claims 38 to 47, characterized in that a lighting control module (14) is provided, which controls the Beieuchtungs- arrangement (3) such that pulsed primary light (PL) is irradiated against the fiber strand (FS), wherein the pulses are synchronized with the generation of the cell-shaped images (Z1 ... Z12).

49. Apparatus according to claim 48, characterized in that the lighting control module (14) for the continuous and automatic adaptation of the intensity of the primary light (PL) to the evaluation by the unit (10) determined reflection properties of the fiber strand (FS) is formed.

50. Device according to claim 48 or 49, characterized in that the illumination control module (14) is a D / A converter (26) for receiving digital

Control and / or control signals for controlling and / or regulating the lighting arrangement (3) is assigned.

51. Device according to one of claims 38 to 50, characterized in that the illumination arrangement (3) comprises a light-emitting diode (4).

52. Device according to one of claims 38 to 51, characterized in that the line sensor (8) comprises a plurality of arranged in a row photodiodes (9).

53. Device according to claim 52, characterized in that each photodiode (9) is assigned a charge store (21) and / or an amplifier circuit (22).

54. Device according to one of claims 38 to 53, characterized in that the line sensor (8) is associated with a lens (6).

55. Apparatus according to claim 54, characterized in that the lens (6) has a diaphragm (7), which is preferably adjustable.

56. Device according to one of claims 38 to 55, characterized. in that an A / D converter (23) for converting the sensor signals (SE) is assigned to the line sensor (8).

57. Device according to one of claims 38 to 56, characterized in that a power supply (18) is provided, which includes an internal Energiequel- Ie, for example, a battery or battery pack (19), or which can be connected to an external power source.

58. Device according to one of claims 38 to 57, characterized in that a display unit, in particular a display (11), is provided for displaying output values and / or operating states of the device.

59. Device according to one of claims 38 to 58, characterized in that a wireless or wired interface (12), in particular a GSM interface, a Bluetooth interface, a Can-Link interface or a USB interface, to Transmission of outgoing data (AD), in particular generated line-shaped images (Z1 ... Z12), generated two-dimensional images (ZDB), operating states of the device, fault messages, evaluation results and / or control commands, and / or incoming data (ED), in particular of software, software updates and / or parameters for the evaluation, such as threshold values, is provided.

60. Device according to one of claims 38 to 59, characterized in that it comprises a substantially closed housing (2), wherein a window (5) for exiting the primary light (PL) and for the entry of the secondary light (SL) is provided.

61. Device according to claim 60, characterized in that the window (5) comprises sapphire glass.

62. Apparatus according to claim 60 or 61, characterized in that a guide device (20) is provided for guiding the fiber strand, which in the

Cross-section is U-shaped, wherein the window (5) is formed on the inside of the base of the U's.

63. Device according to one of claims 38 to 62, characterized in that a guide device is provided for guiding the fiber strand, which is formed so that the fiber strand (FS) is guided on all sides.

64. Device according to one of claims 38 to 62, characterized in that a guide device (20) is provided for guiding the fiber strand, which is formed so that the fiber strand (FS) transversely to its longitudinal direction

(LR) in the guide device (20) can be brought.

65. Device according to one of claims 38 to 64, characterized in that it as an independent module (1), which by means of a releasable mechanical connection (16), for example with a clamping connection, a plug connection, a magnetic connection (16) and / or a latching connection to a textile machine (100) can be fastened, is formed.

66. Apparatus according to claim 65, characterized in that required wired electrical connections between the module (1) and the textile machine (100) by means of releasable electrical connection means (17) can be produced.

67. Device according to claim 66, characterized in that the electrical connection means (17) arranged on the module (1) contacts (17a) and corresponding thereto, arranged on the textile machine (100) contacts (17b) um- believe it.

68. Textile machine, characterized in that it has a device according to one of claims 12 to 63 or for fixing a module (1) formed device according to one of claims 65 to 67 prepared.