Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/8806—Specially adapted optical and illumination features
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/88—Investigating the presence of flaws or contamination
  • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
  • G01N21/8914—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the material examined
  • G01N21/8915—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the material examined non-woven textile material

Definitions

• the invention relates to a device for detecting foreign matter in a yarn with the aid of a detector which scans the yarn, which is exposed by a lighting element, line by line.
• Such a device is known, for example, from DE 41 31 664, in which the yarn is wound onto two rollers in such a way that a layer with several adjacent sections of the same yarn is produced.
• On one side of this layer there is a light source and on the other side there is a camera that is connected to a computer that stores an image processing program.
• the camera creates an image of the layer in which foreign substances such as shell parts can be recognized and counted depending on their properties.
• the layer can be shifted so far that neighboring sections of the yarn are brought into the field of view of the camera. In this way, the entire length of a steam sample can be recorded and checked gradually.
• a disadvantage of the device mentioned is that it can only work discontinuously and at a limited speed. This is because the yarn is supposed to stand still for the formation of an image.
• the device mentioned also takes up a lot of space and cannot be integrated into existing and known overall testers, which are intended for other tests on the game.
• the invention solves the problem of creating a device of the type mentioned, in which yarn can be checked continuously, with good resolution and at high speed without destruction.
• this is achieved in that a compact unit consisting of a sensor or detector, a lens and a lighting element is formed, these elements having a common axis and the lighting element allowing the yarn to be illuminated with a very high light intensity.
• the lighting element is hemispherical formed and has light sources distributed over the hemisphere, which predominantly throw their light rays directly onto the center of the hemisphere.
• the gam is in motion, or, more precisely through this center, gam is moved and a section of the yarn imaged on the detector lies for the Moment of admission at least in the area of this center
• the device according to the invention can be designed to be very space-saving and can thus be used as part of an existing system for testing yarns. Since the device should no longer detect foreign substances in a two-dimensional search field, Instead, the length of the gam is only sensed, which results in a comparative observation of the yarn in a single dimension, its length. This is how the test takes place independently of influences that could have originated from other, adjacent gam sections. This also results in a more neutral detection of the yarn Any foreign substances that may be present, all of which, due to their shape or color, emerge from the section of yarn in which they are also contained. Due to the intensive lighting, the gam can be moved at high speed and a useful signal can still be detected
• FIG. 1 shows a part of the device according to the invention in a perspective view
• FIG. 2 the part in supervision
• Figure 3 shows the part in section
• Figure 4 is a schematic representation of the entire device
• FIG. 1 shows a lighting element 1 with an end compartment 2 and a hemisphere 5, in which openings for light sources are arranged
• Figure 2 shows the inside kugelsymmet ⁇ sch trained lighting element 1 with its planar here Endflache 2, led to the spaced and pa r allele a yarn 3, and is moved in its longitudinal direction in a known manner can be seen the base circle 4 of a Hemisphere 5, the axis of symmetry 6 of which extends perpendicular to the plane of the drawing.
• the hemisphere 5 has a plurality of openings 7, 8, 9, 10 into which light sources in the form of light-emitting diodes, light guides, etc. are inserted.
• the hemisphere 5 has a further sector 12 with the same distribution of the openings and sectors 13, 14 with a different, but among themselves the same distribution of the openings on.
• the opening 10 are preferably arranged such that no opening is covered by the gam 3. This measure avoids disadvantageous casting shadows the gam 3
• the hemisphere 5 preferably has a coating of white color against the yarn 3, which requires multiple reflections of the light and thus strong but diffuse illumination of the yarn
• the lighting element 1 shows the lighting element 1 in section with the symmetry axis 6 and the opening 15 for the detector or for an optical system imaging on the detector, and openings 16, 17 for light sources whose axes 18, 19 intersect at a center 20 with the symmetry axis It is envisaged that the axes of the other openings shown also intersect in the center 20.
• the lighting element 1 consists of opaque material. It extends across the yarn on the one hand and along the yarn on the other hand. This also applies in particular to the cavity 27 instead of one as shown here Hemisphere, the lighting element 1 can also have a differently designed inner surface 26 which, however, like the surface 26 here, is always directed towards the gam 3 and delimits a cavity 27 adjacent to the gam 3 with openings for light sources, etc. This surface 26 could also, for example have an oval or cylindrical shape but the arrangement is important of the light sources, all of which should essentially be directed towards a center 20
• FIG. 4 shows the entire device with the lighting element 1, the yarn 3 and the axis of symmetry 6.
• a detector 22 which is connected via a bus or line 23 to a computer 24 as a detector preferably a field with cell-shaped sensor elements or a CCD camera is provided.
• the lens 21 reduces the image of the chamois, for example, in a ratio of 14, so that relatively small sensor elements, for example the dimension 0 06 mm ⁇ 0 015 mm, can be used Shell part of about 0 5 mm in diameter from the narrow side of a detector element.
• the computer 24 has programs which allow it to filter the signals of the detector and compare them with predetermined threshold values in order to recognize existing foreign substances and to store the number and size of foreign substances
• a background 25 is arranged for the yarn ⁇ a cover whose facing against the lighting element 1 side of inchesbare, preferential White hemisphere may have a cover glass against the gam 3, to prevent contamination in the openings 7 8 9 10 etc.
• the cover 25 could also be hemispherical and optionally with openings for Providing light sources If, for example, dark foreign substances in a yarn of light color are to be recognized, the background, ie the cover 25, is also of a light color. This requires the desired multiple reflections of the light between the lighting element 1 and the cover 25
• the mode of operation of the device according to the invention is as follows
• the game 3 is, for example, moved past the center 20 of the device at a speed of 400 m per minute and is very intensely illuminated with incident light by the light sources in the openings 7, 8, 9, 10 and corresponding openings in the other sectors 12, 13 14 partially reflected in the main axis 6 and can be detected by the detector 22.
• a particularly bright and homogeneously illuminated central area is generated in the immediate vicinity of the center 20. This area can be limited by blinds in front of the detector 22 or by the dimension of the detector elements but also, for example, so that it extends further along the chamfer 3 than across the yarn 3, so that a very small resolution can be achieved.
• blue light is used, as is known, for example, from elements known per se, such as LEDs (light-emitting diodes). , Laser, etc.
• LEDs light-emitting diodes
• Laser etc.
• Foreign substances are generated in the yarn, as these are often brown, yellowish or reddish in color.
• a foreign substance present in the yarn 3, which stands out due to its size, which exceeds the diameter of the yarn, or its color, which differs from the color of the yarn changes the intensity of the reflected light, which is detected by the detector 22.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
• Treatment Of Fiber Materials (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1999
  • 1999-09-27 JP JP2000574916A patent/JP4543404B2/ja not_active Expired - Fee Related
  • 1999-09-27 EP EP99944215A patent/EP1117990A1/de not_active Ceased
  • 1999-09-27 CN CNB998115827A patent/CN1186623C/zh not_active Expired - Fee Related
  • 1999-09-27 WO PCT/CH1999/000458 patent/WO2000020849A1/de not_active Application Discontinuation
  • 1999-09-27 US US09/806,439 patent/US6944323B1/en not_active Expired - Fee Related

Non-Patent Citations (1)

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