DE29621093U1 - Measuring device - Google Patents

Description

Equipment for measuring

The proposed device relates to the field of measurement, in particular the measurement of materials which may be in the form of a sheet or sheet. These materials often have their edge or the position of one of the edges of this material measured, for which purpose an optical system can be used which can operate effectively essentially perpendicular to the edge of the said material.

The optical system mentioned usually has at least one light transmitter and at least one appropriate receiver. Such devices are usually operated with the usual visible light that a conventional light source is able to emit. Attempts have also been made to use mechanical edge sensors in order to be able to keep the material in question on a predetermined or desired path. This is particularly important when this material is moving, i.e., for example, changes its position along the predetermined path. This is the case, for example, with web-shaped materials when they run through a corresponding processing device or a corresponding production device, such as in paper machines, printing machines or winding machines.

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machines. Due to the manufacture or processing of the materials mentioned, it is necessary that these materials follow a certain path when they pass through the machine device intended for them and that these materials also follow the path intended for them. However, this is not always the case, because the materials often run very slightly perpendicular to the direction of travel intended for them, which is usually referred to as an error in the so-called side register. The material can be in the form of webs or in the form of passing sheets, whereby the webs often have to run through their intended path more quickly than the sheets. In order to be able to keep the materials mentioned on their intended path, mechanical methods and devices have already been used, but optically effective devices and methods are also known which work with the light that is usually visible to the human eye. In addition, infrared light has already been used or even devices that work with ultrasound. Such a device has become known, for example, due to the German patent application 195 06 467, which works with infrared light. The mechanical devices, through which the materials in question pass, often work in larger rooms, such as factory halls and are therefore also exposed to environmental influences. For example, the effectiveness of the systems mentioned

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Heat-emitting dryers may have a negative effect, for example if the device in question is to work with infrared light. However, if visible light is used, for example, light sources in the immediate vicinity often lead to incorrect readings from the device in question, which unpleasantly disrupts the production process of the machine device. For example, sunlight can affect the receivers of measuring systems that work with visible light, so that the ^system works perfectly when the weather is cloudy, for example, and unpleasant disruptions occur when sunlight can enter through the window of a factory hall. There is therefore a need to design devices of the type in question in such a way that they are largely insensitive to so-called extraneous light. This is achieved with a device as outlined in the appended claims. Further inventive features and advantages of the device according to the invention emerge from the following description of at least one exemplary embodiment. The individual features of the exemplary embodiment can be implemented individually or in any combination with the aid of specialist knowledge to form further embodiments of the invention. On the basis of the embodiment shown schematically in the at least one attached figure, which explains the inventive concept and does not limit it,

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the proposed solution is now explained in more detail. The at least one embodiment can also be modified in various ways or supplemented by further embodiments without leaving the framework defined by the basic idea. In the attached at least one figure, non-essential machine parts that are sufficiently well known to the person skilled in the art are not shown in order to make the illustration clearer. Rather, the at least one figure only shows those parts that are necessary for the detailed explanation of the proposed solution and its advantages. To support and supplement the present description, reference is expressly made to the prior publications cited on the previously known state of the art in order to avoid unnecessarily complex repetitions. Based on the suggestions presented, it is therefore no longer necessary for the person skilled in the art to be inventive, for example, in order to make use of his or her specialist knowledge to carry out further applications, to open up other areas of use or to develop further embodiments if this should prove to be advantageous or even necessary from a design point of view.

The individual figures mean:

Fig I: Side view

Fig 2; section in direction II in Fig.l on a different scale

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A material 1 runs through a machine device along a path, which can be defined, for example, by rollers 2 and 3. Rollers 2 and 3 are rotatably mounted in a machine frame (not shown in detail). Material 1 can be in the form of sheets or in the form of an endless web 4, which runs through the machine device in the direction of arrow 5 and, for example, partially wraps around rollers 2 and 3. In this context, rollers 2 and 3 can be, for example, so-called guide rollers. Material 1 can consist of paper, for example, but also of plastic, so-called film, in particular film that is transparent to the human eye, but also of metal films. It can also consist of textiles, which can also be provided with some kind of coating, for example. The thickness of these materials or of the material in question can vary greatly; it can vary between a few millimeters and a few thousandths of a millimeter or less. On its way through the machine, the material 1 passes a light source 6. The light 7 emitted by the light source 6 is usually picked up by a receiver 8. The receiver 8 reports its observations via lines 9 and 10 to a control device 11. This can then give appropriate correction commands, for example to tilt the roller 2 or 3 so that the material 1 deviates slightly from its previous path. The light 7 adjusts

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Starting from its source 6, the light source 8 passes through, for example, a lens system 12 and a polarization filter 13 on its way to the receiver 8. In the direction of the light flux 14, the lens system 12 can also be swapped with the polarization filter 13, so that the light flux 14 first passes through the lens system 12 and then the polarization filter 13, for example. In addition, the lens system 12 and the polarization filter can be directly integrated into the housing of the light source 6. On its way to the receiver 8, the light flux 14 can pass through another polarization filter 15. This can also be omitted if necessary. The receiver 8 is provided with a CCD field 16, for example in such a way that the CCD field 16 and the receiver 8 are connected as a structural unit to form a so-called CCD camera. The optical device outlined by parts 6 to 16 is arranged in such a way that the light stream 14 reaches the receiver 8 at least partially, namely because the material 1 running towards or away from the viewer in the viewing direction of Fig. 2 partially interrupts the light stream 14 or is in the way of it. In addition, however, it is also possible that the material 1 does not impair the light stream 14 in any way or can completely prevent it, depending on the position of the edge 17 of the material 1, because ultimately, due to the conditions described above, it is possible that the material 1 can move in the direction of the double arrow 18. Depending on the size

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of the light flux acting on the receiver 8 or the CCD field 16, different commands are sent to the control device 11 and thus different positions for the edge 17, since this changes when the material 1 deviates from its previous path due to, for example, the inclination of the roller 3. Since the polarization filters 13 and possibly 15 are switched on in the light flux 14, the possibility arises that polarized light, i.e. light oscillating in a plane of oscillation, can act on the material 1 or its edge 17. The CCD field 16 and thus also the camera 8 react to this polarized light and accordingly, depending on the position of the edge 17 of the camera 8, shows more or less polarized light, i.e. the camera 8 is ultimately informed of the position in relation to the double arrow 18 of the edge 17 of the material 1. It has been found that polarized light, ie polarized light effective at least on the material 1 or its edge 17, can influence the camera 8 or the CCD field 16 in such a way that only the polarized light produces clear measurement signals in the lines 9 and 10. In contrast, unpolarized light remains largely without influence, ie without undesirable ie damaging influence on the camera 8 or the control of the path of the material I, so that the extraneous light mentioned above cannot irritate the proposed device. In addition, it has been found that

shows that even films that are transparent to the human eye, such as plastic films, can be detected very easily and clearly by the polarized light, so that a reliable device is created for the processing or working of these materials. The light source 6 represents a light transmitter in this context, whereas the CCD field 16 or a camera equipped with such a field represents a receiver, as is indicated by the reference number 8. As can be seen in Fig.2, the transmitter and receiver are assigned to different sides of the material 1, such as the transmitter in Fig.2 at the top and the receiver in Fig.2 at the bottom. However, it is also possible to place the transmitter in Fig.2 at the bottom and the receiver at the top, or to provide the device in such a way that the transmitter and receiver are assigned to the same side of the material, such as both above the material 1, in order to make them work in the so-called reflex process. The optical device 6 to 16 as a whole, in particular together with the lines 9 and 10 and the control device 11 as well as the associated actuating device, represents an essentially optically effective system.

Parts list

1 Materials

2 roller

3 roller

4 track

5 Arrow

6 Light source

7 Light

8 recipients

9 Management

10 Line

11 Control device

12 lens system

13 Polaris.Filter

14 Luminous flux

15 Polaris.Filter

16 CCD field

17 Edge

18 Double arrow

Claims (3)

Expectations 1.) Device for measuring the edge (17) of a web-shaped or sheet-shaped material (1) with the aid of an optical system (6-16) operating essentially perpendicular to the edge of the material (1), which comprises at least one light transmitter (6) and at least one appropriate receiver (8, 16), characterized by a light transmitter (6) emitting polarized light. 2.) Device according to claim 1, characterized by a receiver (8) having a CCD field (16). 3.) Device according to claim 1, characterized in that the transmitter (6) and the receiver (8) are assigned to different sides of the material (1).