EP4074879A1 - Method for identifying foreign objects in double-layer laundry items - Google Patents

Abstract

It happens that in laundries, double-layered items of laundry (10) have to be treated that contain at least one foreign object that causes a topographical anomaly (26) on at least one outside (25) of the respective double-layered item of laundry (10). This leads to problems at least when such double-layered items of laundry (10) are folded. The invention provides for determining whether double-layered items of laundry (10) have topographical anomalies (26) or other anomalies caused by foreign objects at the latest before folding. Such double-layered items of laundry (10) are then at least no longer folded, so that they cannot cause any problems in the folding machine (17).

Description

The invention relates to a method for detecting foreign objects in double-layered items of laundry according to the preamble of claim 1.

It can happen that there are foreign objects in double-layered items of laundry, such as pillowcases or duvet covers in particular. These can be objects of all kinds. However, there are often other items of laundry in double-layered items of laundry, namely both single-layered and multi-layered items of laundry or items of clothing, such as bathrobes, for example. Such textile objects are often gathered up or even crumpled up and thrown into a double-layered item of laundry. The double-layered item of laundry then serves, so to speak, as a pocket for one or more foreign objects.

It also happens that when washing in a washing machine, foreign objects, in particular other items of laundry, get caught in a double-layered item of laundry.

Foreign objects in double-layered items of laundry cause problems when they are treated in laundries, which affect or at least can affect subsequent treatments of the items of laundry after washing. In extreme cases, this can lead to damage to the laundry machines downstream of the washing machine. This also applies to foreign textile objects that are balled up. Any foreign objects in double layers Laundry items lead to anomalies that impair or even make impossible the intended treatment of the laundry items, at least the folding, but possibly also the mangle. Such anomalies are, for example, topographical elevations on the at least one outside or side surface of double-layered items of laundry. This can involve localized widening or bulging of the normally adjacent layers of opposite outer sides or side surfaces of the laundry items. Seen figuratively, the at least one foreign object locally bulges out of the double-layered item of laundry.

If such anomalies, particularly of a topographical nature, run through a normally narrow gap in the ironer, this leads to increased surface pressure in the area of the foreign objects. This can, for example, have a negative effect on the windings of mangle rollers and even damage them if the winding has a spring system made up of interlinked lamellar springs. Anomalies, in particular topographical anomalies, such as bulges caused by foreign objects on at least one outside of the double-layered laundry items, are particularly critical in folding machines. Such items of laundry cannot be folded. If they nevertheless get into a folding machine, this can lead to malfunctions of the same.

The invention is now based on the object of creating a method for determining foreign objects in double-layered items of laundry, as a result of which operational interruptions and/or damage caused by foreign objects in double-layered items of laundry are avoided.

A method for solving this problem has the measures of claim 1. In this method, it is intended to determine anomalies caused by foreign objects in double-layered laundry items without contact from the outside. As a result, any foreign objects in double-layered items of laundry can be identified before such items of laundry are treated in laundry machines and can thereby cause damage and/or malfunctions of laundry machines. In addition, it is avoided in this way that the double-layered laundry items to be treated are impaired during the treatment due to the foreign objects present therein. Above all, impairments when mangling and/or folding can be reliably avoided.

The non-contact detection of foreign objects from at least one outside of the respective double-layered item of laundry is preferably carried out as early as possible so that double-layered items of laundry containing foreign objects do not have to be treated unnecessarily and thereby suffer damage themselves or damage a laundry treatment machine. Because foreign objects can already be present in double-layered items of laundry when they are delivered to the laundry, but foreign objects in the form of other items of laundry can also get into double-layered items of laundry during washing, for example, foreign objects in double-layered items of laundry are identified at the earliest before the washed items of laundry are ironed. Then, when ironing double-layered items of laundry, foreign bodies cannot impair either the mangle or the subsequent folding machine and also the stacker that may follow, and above all cannot be damaged during the mangle itself.

In the case of large mangles, mangles that have no underspring between the mangle roller and the winding, or even sliver mangles, foreign bodies in double-layered items of laundry cannot cause any or at least no serious impairment of such mangles. It can then be sufficient if foreign bodies in double-layered items of laundry are detected without contact from the outside only before the folding machine.

It is also advantageous to carry out the non-contact external determination of foreign objects in double-layered items of laundry together with the determination of other parameters of the items of laundry to be treated. Then no separate devices are required for the determination of foreign objects in double-layered laundry items. Rather, the determination of foreign objects in the laundry is made with the same devices that also other parameters of the laundry such. B. Dimensions, determine the type of laundry and / or how they are treated.

Advantageously, the determination of anomalies caused by foreign objects in double-layered items of laundry and to be determined by the method according to the invention are those that visibly emerge on at least one outside of the respective item of laundry. In particular, there are such anomalies that appear permanently on at least one outside when at least one foreign object is present in the double-layered item of laundry and/or at least one bulge or outwardly pointing bulge on at least cause an outside of the double-layered item of laundry. Such anomalies, which are characteristic of foreign objects in the respective double-layered item of laundry, can be reliably and automatically detected from the outside without contact.

An advantageous possible embodiment of the method provides for the respective double-layered item of laundry to be scanned with at least one non-contact scanning device with regard to at least one foreign object present therein. This can be done, for example, by ultrasound or laser. Distance dimensions to the scanned outside of the respective double-layered item of laundry are obtained by preferably full-area raster-like scanning. If the distance dimensions vary at certain points on the outside of the respective double-layered item of laundry, this indicates an anomaly in the form of a topographical anomaly, such as an elevation, a bulge and/or bulge. In particular, significant changes in distance are taken into account, which are not caused by folding the item of laundry but by topographical changes, bulges and/or bulges that protrude significantly more outwards and are caused by foreign objects in the double-layered items of laundry.

An alternative advantageous embodiment of the method provides for anomalies, in particular topographical anomalies, namely changes, on at least one outside of the respective double-layered item of laundry, which are caused by at least one foreign object in the double-layered item of laundry, to be detected contactlessly from the outside by at least one imaging device. The at least one imaging device can be a camera, in the simplest case a black/white camera, but also a color camera. The camera must be suitable for determining topographical anomalies on at least one outside of the respective double-layered item of laundry and, in particular, for distinguishing topographical anomalies from any folds in the item of laundry.

According to an advantageous embodiment of the method, anomalies, in particular on at least one outside of the respective double-layered item of laundry, are determined by at least one imaging device when the double-layered item of laundry is x-rayed. For this purpose, a light source is preferably assigned to an outer side or side surface of the respective item of laundry and at least one imaging device is arranged in the vicinity of the opposite outer side or side surface. Light generated by the light source then only occurs at such Areas through the double-layered item of laundry and/or makes it appear lighter than an area in which a respective foreign object is located in the double-layered item of laundry. Less light or no light at all shines through here. If at least one foreign object is present in the double-layered item of laundry, a dark or darker spot is then produced by the foreign object or the respective foreign object, which can be perceived by a light-sensitive imaging device. The at least one dark or darker spot then represents an anomaly which can be detected by the imaging device and which indicates the presence of at least one foreign object in the double-layered item of laundry. Such items of laundry can be sorted out before they are affected by at least one foreign object and/or the at least one foreign object in the respective double-layered item of laundry affects a downstream laundry machine, in particular a mangle and/or folding machine, and/or leads to malfunctions.

Advantageously, the method is designed or developed in such a way that anomalies caused by foreign objects in the double-layered items of laundry are determined when the items of laundry are hanging, in particular hanging in a spread out manner. This facilitates a reliable and full-surface inspection of at least one outside or side surface of the respective double-layered item of laundry with regard to anomalies that are caused by at least one foreign object in the item of laundry in question.

Alternatively, it is conceivable to determine anomalies caused by at least one foreign object in lying double-layered laundry items, preferably flat and/or spread out double-layered laundry items. This determination preferably takes place with items of laundry lying on a conveyor. Such a check of the double-layered items of laundry with regard to any foreign objects located therein can be carried out continuously while the item of laundry is being transported on the conveyor, but also when the conveyor is stopped for a short time.

Any anomalies, in particular bumps, bulges or differences in brightness of each individual double-layered item of laundry are preferably determined from the outside without contact. In particular, at least one outer surface of the respective hanging double-layered item of laundry is determined over the entire surface or at least one upper side of the respective lying, in particular spread out, double-layered item of laundry over the entire surface. This determination is made on the outside by grid-like distance measurements or by scanning at least one side surface or outside of the relevant double-layered item of laundry or by a topography recorded by at least one imaging device of at least one outside or surface of the double-layered item of laundry or also the determination of brightness differences.

In an advantageously designed method, provision is made for data sets, preferably distance values, determined by at least one non-contact distance measuring device to at least one outside of the respective item of laundry to be evaluated automatically by a computer, for example. If at least one anomaly is detected in the respective double-layered item of laundry, this item of laundry is not subjected to any subsequent treatment, in particular not mangle and fold or at least not fold.

If, alternatively, foreign objects in a double-layered item of laundry are determined without contact by at least one imaging device, the method provides in particular for images, image data records or brightness values determined by the at least one imaging device to be automatically evaluated, for example by an evaluation device. If at least one anomaly is detected, for example a bulge or a difference in brightness, for example a dark or darker area and/or a shadow, in a double-layered item of laundry, this item is not subjected to any subsequent treatment, in particular not mangled and not folded, or at least not folded.

Fig. 1

eine schematische Seitenansicht einer Behandlungsstraße für Wäschestücke in einer Wäscherei,

Fig. 2

eine perspektivische Ansicht einer Eingabemaschine, einer Mangel und einer auf die Mangel folgenden Faltmaschine,

Fig. 3

eine Ansicht analog zur Fig. 2 eines anderen Ausführungsbeispiels der Erfindung,

Fig. 4

eine Ansicht analog zur Fig. 2 für ein weiteres Ausführungsbeispiel,

Fig. 5

eine Möglichkeit der Ermittlung eines Fremdkörpers in einem doppellagigen Wäschestück mittels einer bildgebenden Einrichtung,

Fig. 6

eine Darstellung analog zur Fig. 5 aus einer anderen Blickrichtung, und

Fig. 7

eine alternative Möglichkeit der Ermittlung eines Fremdkörpers in einem doppellagigen Wäschestück.

Preferred exemplary embodiments of the invention are explained in more detail below with reference to the drawing. In this show:

1

a schematic side view of a treatment line for laundry items in a laundry,

2

a perspective view of a feeding machine, a mangle and a folding machine following the mangle,

3

a view analogous to 2 another embodiment of the invention,

4

a view analogous to 2 for another embodiment,

figure 5

a possibility of detecting a foreign body in a double-layered item of laundry using an imaging device,

6

a representation analogous to figure 5 from a different perspective, and

7

an alternative way of detecting a foreign body in a double-layered item of laundry.

A possible device for carrying out the method according to the invention is shown as an example in the figures. However, the process should not be restricted to this.

the 1 shows a possible treatment line for the laundry items in which the method according to the invention can be used. The treatment line is used to treat so-called mangle laundry. This is primarily flat linen such as bed linen and table linen. The bed linen also includes multi-layer, in particular two-layer, items of laundry, namely duvet covers and pillowcases. Such two-ply items of laundry 10 are partially shown in the figures. Only two-ply items of laundry 10, but also single-ply items of laundry, such as sheets, tablecloths, serviettes or similar items of laundry, can be treated by the treatment line shown. Along the treatment line, two-ply items of laundry 10 and one-ply items of laundry can be sorted into consecutive batches, but also unsorted, ie mixed up, are treated. The double-layered items of laundry 10 and also other items of laundry run through the treatment line in the treatment direction 11 (in the 1 from left to right and in the Figures 2 to 4 from right to left).

The one in the 1 The treatment line shown as an example has, in treatment direction 11, a washing machine 12, a dewatering press 13, or another dewatering device such as a centrifugal dewatering device, at least one dryer 14, at least one mangle 15, which is preceded by an input machine 16, at least one folding machine 17 and one Stacking device 18 behind the respective folding machine 17. Optionally, as shown in FIG 1 a laundry item store 19 may be arranged in front of the input machine 16 . The items of laundry run through the treatment line in the treatment direction 11. Optionally, in front of the at least one Washing machine 12 may be arranged a sorting station and / or a conveyor system for storing laundry items to be washed. These are in the 1 not shown.

At the in the 1 Several imaging devices 20, 21, 22 and 23 are shown in the treatment line shown. These can be cameras, for example, which do not necessarily have to generate an image of the respective double-layered item of laundry 10 or another item of laundry, but alternatively also differences in brightness or moisture. At least one imaging device 20 can be provided on the laundry item storage 19, at least one imaging device 21 in front of the input machine 16, at least one imaging device 22 in front of the mangle 15 and/or at least one imaging device 23 in front of the folding machine 17. To carry out the method according to the invention are not all mentioned and in the 1 arranged imaging devices 20 to 23 required. It is sufficient if at least one imaging device is provided in front of the input machine 16, in front of the folding machine 17 or in front of the spacing device 18 in order to be able to carry out the method according to the invention. This does not preclude the other imaging devices from being assigned to the treatment line for another purpose as well.

In the embodiment of 2 the imaging device 23 is arranged between the mangle 15 and the folding machine 17, specifically in the area of a transfer belt conveyor 24, which transports the respective ironed item of laundry, in particular a double-layered item of laundry 10, from the mangle 15 to the folding machine 17. The folded, double-layered item of laundry 10 is then spread out flat on the upper run of the transfer belt conveyor 24. An outside 25, preferably the entire outside 25, of the upper layer of the double-layered item of laundry 10 is freely visible in that it is exposed. In the 2 a topographical anomaly 26 is shown in, for example, a corner area of the outside 25. The topographical anomaly 26 is z. B. formed by a crumpled up foreign item of laundry inside the double-layered item of laundry 10. As a result, due to the lower layer of the double-layered item of laundry 10 lying flat on the upper run of the transfer belt conveyor 24, a bulge forms in the upper layer, which on the outside 25 of the upper layer of the double-layered item of laundry 10 visibly emerges.

From the 2 It can be seen that the imaging device 23 is arranged above the transfer belt conveyor 24 in such a way that the imaging device 23 can capture the entire outside 25 of the double-layered item of laundry 10 . Here is the imaging device 23 or its optics are designed in such a way that they can capture the entire outside 25 of max.

In the embodiment of 3 at least one lighting device 27 is arranged under the transfer belt conveyor 24 or alternatively between the two strands of the same. In the exemplary embodiment shown, the lighting device 27 is a light bar that runs transversely to the treatment direction 11 and extends over the entire width of the transfer belt conveyor 24 . At least one strip of the double-layered item of laundry 10 extending transversely to the treatment direction 11 is illuminated from below by the elongated lighting device 27 and the double-layered item of laundry 10 is thereby transilluminated by the strip-like lighting device 27 illuminating the outside of the lower layer of the double-layered item of laundry 10 and this light shines through both layers of the double-layered item of laundry 10 . This creates a lighter outer side 25 in the region of the outer side 25 of the upper layer of the double-layered item of laundry 10, which faces towards the imaging device 23 and is visible from it.

Where the topographical anomaly 26 is in the form of a bulge, there is no fluoroscopy or much weaker fluoroscopy compared to the other areas of the double-layered garment 10 adjacent the topographical anomalies 26 where both layers are directly superimposed. In this way, the imaging device can alternatively or additionally detect and register the topographical anomaly 26 in the form of differences in brightness on the outside 25 of the double-layered item of laundry 10 . If necessary, in this case the imaging device 23 does not necessarily have to be designed to generate an image of the outside 25, ie a photograph thereof, but rather only to detect differences in brightness. Alternatively, it is also conceivable for the imaging device 23 arranged downstream of the mangle 15 to detect temperature and/or moisture differences on the outside 25 of the double-layered item of laundry 10 . In this case it is sufficient to design the imaging device 23 as an infrared camera. This then does not record the topography of the anomaly 26 but rather the greater humidity and/or lower temperature caused by at least one foreign object anomaly.

the 4 shows a further exemplary embodiment of a device for carrying out the method. This differs from the embodiment of 2 and 3 thereby, that the imaging device 23 , which is preferably also designed as a camera, is arranged laterally next to an edge 28 of the transfer belt conveyor 24 . This arrangement is such that an optical axis of the imaging device 23, in particular the camera, runs horizontally and lies in a plane that coincides with that of the upper run of the transfer belt conveyor 24 or is slightly above and to the side of the plane of the upper run of the transfer belt conveyor 24. In the latter case, the optical axis of the imaging device 23 runs at an acute angle to the plane of the upper run of the transfer belt conveyor 24.

By arranging the imaging device 23 according to the 4 a side profile of the double-layered item of laundry 10 currently located on the upper run of the transfer belt conveyor 24 and, above all, of the topographical anomaly 26 is determined.

There are other alternatively configured devices for carrying out the method of the invention are conceivable in which, in deviation from the exemplary embodiments of FIG Figures 2 to 4 the imaging device 23 between the mangle 15 and the input machine 16 does not determine topographical anomalies 26, in particular bulges, on the outside 25 of the respective double-layered item of laundry 10. Instead, for example, bulges or other anomalies on the outside 25 of double-layered items of laundry 10 are determined by the imaging device 22 between the input machine 16 and the mangle 15 . This determination is made with a double-layered item of laundry 10 lying spread out on a transfer belt conveyor 29 between the input machine 16 and the mangle 15.

At the in the Figures 2 to 4 In the exemplary embodiments shown, items of laundry, including double-layered items of laundry 10 , are hung by operators 30 in loading clamps 32 held ready at a loading station 31 . It is alternatively in the embodiments of Figures 2 to 4 conceivable to design the device in such a way that the items of laundry and also double-layered items of laundry 10 from the item of laundry store 19 according to the 1 are automatically transferred to the input machine 16. The respective item of laundry, specifically also the respective double-layered item of laundry 10, hangs down from preferably adjacent corners of an edge holding successive clamps 30. The two clamps 33 each holding an item of laundry can also be combined to form a double clamp. The brackets 33 or the respective double bracket are on a rail system from which in the Figures 5 to 7 only one rail section 34 is shown, movable. That The clamps 33 can be moved by a traction element, for example an endless chain, which is arranged in or on the rails of the rail system and which can be driven in a revolving manner. However, it is also alternatively or additionally conceivable for the clamps 33 to be able to be moved further along downwardly inclined rail sections 34 by gravity.

the Figures 5 to 7 show different views of double-layered laundry item 10 hanging in the area of rail section 34 on two clamps 33 each, with a topographical anomaly 26, which is a bulge caused by, for example, a foreign item of laundry crumpled up in double-layered laundry item 10. This bulge then emerges on at least one outer side 35 of the double-layered item of laundry 10 shown hanging down from the clips 33 .

Any topographical anomalies 26 on two-layered laundry items 10 hanging down from two clamps 33 are, according to the exemplary embodiments of FIG Figures 5 to 7 determined before the input machine 16. This can be done by the at least one imaging device 20 in the area of the item of laundry store 19 or by the imaging device 21 directly in front of the feeder 16, namely immediately before the double-layered item of laundry 10 still hanging on the clamps 33 is transferred to the feeder 16.

In the embodiment of figure 5 the imaging device 20 or 21 is arranged in such a way that it captures the outside 35 of the double-layered item of laundry 10 hanging down from the clamps 33, preferably over the entire surface. It may also be sufficient for only a lower region of the respective double-layered item of laundry 10 to be detected by the imaging device 20 or 21 if it can be assumed that the at least one foreign object is located in the lower region of the double-layered item of laundry 10 hanging down due to the force of gravity and that the in the Figures 5 to 7 is shown. A topographical anomaly 26 caused by a bulge on at least the outside 35 of the respective double-layered item of laundry 10 can be detected by the imaging device 20 or 21 , specifically imaged.

In the embodiment of 6 the imaging device 20 or 21 is assigned in such a way relative to the double-layered item of laundry 10 hanging down from the clamps 33 that it is on an edge or an edge of the respective double-layered Laundry item 10 looks. As a result, a topographical anomaly 26, in particular a widening or bulging, can be detected on both outer sides 35 of the respective double-layered item of laundry 10.

the 7 12 shows an exemplary embodiment in which the outside 35 is assigned the imaging device 20 or 21 and at least one lighting device 27 is provided on the opposite, covered outside. The lighting device 27 embodied as a light bar in the exemplary embodiment shown preferably illuminates the entire surface of the outside of the respective double-layered item of laundry 10 facing away from the imaging device 20 or 21 . As a result, the respective double-layered item of laundry 10 is x-rayed at least in the lower area, where a foreign object can be expected to be located. The result is that a foreign object that causes any anomaly, ie not just a topographical anomaly 26, on the outside 35 viewed by the imaging device 20 or 21 appears as a dark spot on the outside 25. In this way, flat foreign objects in the double-layered item of laundry 10 can also be recognized by the imaging device 20 or 21, and not just topographical anomalies 26 in the form of bulges caused by foreign objects crumpled together, in particular foreign items of laundry.

The method according to the invention is explained in more detail below with reference to the devices described above, without the method according to the invention being restricted thereto:
It happens that double-layered items of laundry 10 contain foreign objects when they are delivered to a laundry. For example, mostly crumpled up items of foreign laundry, but also newspapers or the like, are collected in a double-layered item of laundry 10 . The double-layered item of laundry 10 is then used more or less as a pocket or pouch. Such foreign objects make it difficult to treat double-layered laundry items 10 in laundries. It can also happen that when items of laundry are washed batchwise in a double-layered item of laundry 10, an item of laundry from another person gets lost, so to speak. In the cases mentioned above by way of example, the at least one foreign object in the double-layered item of laundry 10 can lead to problems when folding or mangling.

In order to eliminate the problems mentioned, the method according to the invention provides for contactless external anomalies caused by foreign objects in the double-layered item of laundry 10, in particular topographical anomalies 26, such as B. caused by crumpled foreign laundry bulges to determine.

The determination of anomalies, in particular of bulges in at least one outer side 25 of the respective double-layered item of laundry 10, topographical anomalies 26 caused, but also the double-layered item of laundry 10 locally stiffening, which are caused by newspapers or magazines, for example, takes place at the latest before the folding machine 17, because such anomalies at least affect the folding process. However, any anomalies can also be detected earlier without contact, for example before mangle 15.

The non-contact outside determination of anomalies caused by foreign objects in double-layered laundry items 10 can be carried out in the state laid out and lying essentially flat on a conveyor. This can take place in the area of the transfer belt conveyor 24 between the mangle 15 and the folding machine 17, but also in the area of a transfer belt conveyor 29 between the input machine 16 and the mangle 15.

The detection of foreign objects in double-layered items of laundry 10 can also take place upstream of the input machine 16 , the respective double-layered item of laundry 10 then preferably hanging down from at least one clamp 33 . During this determination, the item of laundry is preferably held by two clamps 33 at adjacent opposite corners of an edge of the item of laundry, so that the double-layered item of laundry 10 hangs spread out from the clamps 33 in such a way that anomalies caused by foreign objects in the respective double-layered item of laundry 10, in particular topographical anomalies 26, in the form of bulges, at least on an outer side 35 of the double-layered item of laundry 10.

The outside non-contact determination of foreign objects in double-layered items of laundry 10, in particular of foreign objects in double-layered items of laundry 10 caused anomalies such. B. topographical anomalies 26, can be done by preferably an imaging device 20, 21, 22 or 23 shown in the devices described above, wherein the imaging devices 20 to 23 are preferably cameras. Alternatively, it is also conceivable topographical anomalies 26 by contactless distance measurements using at least one distance measuring device. This is done by many distance measurements preferably distributed in a grid pattern over the entire outside 25 or 35 . For example, a large number of measured distance values can be obtained from a grid of many distance measurements to the outside 25 and 35 carried out without contact using lasers or ultrasound. If there are clear differences in the measured distance values, this indicates a double-layered item of laundry 10 with a topographical anomaly 26 .

If at least one of the imaging devices 20 to 23 is used to determine anomalies in double-layered items of laundry 10 , this can be a camera that takes a picture of the respective outer side 25 or 35 of double-layered items of laundry 10 . Any topographical anomalies 26 at least on the outside 25 or 35 viewed by the respective imaging device 20, 21, 22 or 23 are recorded. Such topographical anomalies 26 can be detected by the imaging devices 20, 21, 22 or 23 from different viewing angles, preferably perpendicularly or almost perpendicularly to the respective outside 25 or 35 or transversely or almost transversely to the outside 25 or 35. In the latter case the view of the respective imaging device 20, 21, 22 or 23 is directed towards a rim 28 of the respective double-layered item of laundry 10. The viewing direction can also run slightly obliquely, preferably at an acute angle, to such an edge 28 . In this case, the lateral profile of the respective topographical anomaly 26 can be determined by the imaging device 20, 21, 22 or 23, possibly also on the two opposite outer sides of the respective double-layered item of laundry 10.

Foreign bodies in the double-layered item of laundry 10 can also be detected when the double-layered item of laundry 10 is x-rayed. As a result, the respective double-layered item of laundry 10 is x-rayed where there is no foreign object, in particular where there is no anomaly. In the area of the foreign object, on the other hand, the double-layered item of laundry 10 is not x-rayed at all or is only weakly x-rayed. As a result, a darker spot or shadow is formed on that outside 25 or 35 of the relevant double-layered item of laundry 10 to which the imaging device 20, 21, 22 or 23 is assigned. This darker spot is indicative of an anomaly, which may not necessarily be a topographical anomaly 26, specifically when not if it is a flat foreign object, for example a newspaper or a magazine in the double-layered item 10 of laundry. The one-sided illumination or transillumination of double-layered items of laundry 10 makes it possible to detect any anomaly caused by foreign objects in double-layered items of laundry 10 without contact using imaging devices 20, 21, 22 or 23, not just topographical anomalies 26. For this reason, in the case of and/or x-raying double-layered items of laundry 10, the imaging device 20, 21, 22 or 23 can be designed in such a way that it only detects differences in brightness that are caused by all anomalies, not just topographical anomalies 26.

After ironing, pockets of moisture and/or temperature differences form where there is a foreign object. In this case, the anomalies can be detected contactlessly from the outside of the respective double-layered item of laundry 10 by such imaging devices 20, 21, 22 or 23 which are suitable for detecting temperature differences or differences in humidity on at least one outside 25 or 35 of the respective double-layered item of laundry 10 without contact to investigate. The imaging devices 20, 21, 22 or 23 then do not necessarily have to be designed to produce an image of the outside 25 or 35 of the double-layered item of laundry 10.

The distance data determined by distance measuring devices or by imaging devices 20, 21, 22 or 23, in particular data records, are evaluated electronically in an evaluation device, in particular an image evaluation, specifically to determine whether the data reflect topographical deviations, differences in brightness, temperature differences and/or Moisture differences on at least one or individual points on at least one outside 25 or 35 of the respective double-layered item of laundry 10 result. Such deviations then indicate an anomaly caused by at least one foreign object in the double-layered item of laundry 10 . The double-layered item of laundry 10 tested in each case must then be one in which at least one foreign object is located.

Depending on where the determination of the anomaly took place, the relevant double-layered item of laundry 10 with at least one foreign object inside is sorted out before mangling or at the latest before folding. Such a double-layered item of laundry 10 is then preferably manually freed from at least one foreign object and then fed back into the treatment process at a suitable point in order to be treated finally and completely.

The imaging devices 20, 21, 22 or 23 used to identify foreign objects in the double-layered item of laundry 10 are preferably used not only to identify anomalies caused by foreign bodies in the double-layered item of laundry 10, in particular topographical anomalies 26, but preferably also to identify other anomalies affecting the respective item of laundry Information. For example, this can be information about whether the respective item of laundry is a single-layer or double-layer item 10 of laundry. Then only double-layered laundry items 10 need to be checked for the presence of at least one possible foreign object in them. If this check takes place with imaging devices 20, 21, 22, 23, other information about the relevant item of laundry can also be determined with the same. An additional, separate imaging device 20, 21, 22 or 23 for carrying out the method according to the invention is thus unnecessary.

If the treatment line has imaging devices 20, 21, 22 or 23 at different points, it can be useful to use imaging devices 20, 21, 22 or 23 that are already present at different points to check whether double-layered laundry items 10 contain at least one foreign object or Not. As a result, a repeated check for the presence of foreign objects in double-layered items of laundry takes place, which increases the reliability of the check, ideally leading to 100% reliability.

The method according to the invention is not limited to a treatment line that 1 is shown. This is just an example. In particular, the treatment line does not need to have imaging devices 20, 21, 22 and 23 at the locations shown in the figure. the 1 12 only shows possibilities where the imaging devices 20, 21, 22 and 23 can be present in the course of a laundry line. A single imaging device 20, 21, 22 or 23 is sufficient to carry out the method according to the invention, preferably the imaging device 22 or 23.

Reference list:

10

double-layered laundry

11

direction of treatment

12

Washing machine

13

dewatering press

14

dryer

15

defect

16

input machine

17

folding machine

18

stacking device

19

laundry storage

20

imaging facility

21

imaging facility

22

imaging facility

23

imaging facility

24

transfer belt conveyor

25

outside

26

topographical anomaly

27

lighting device

28

edge

29

transfer belt conveyor

30

operator

31

loading station

32

loading clamp

33

bracket

34

track section

35

outside

36

lighting device

Claims (11)

Method for detecting foreign objects in double-layered items of laundry (10) which are at least washed, mangle and/or folded, characterized in that anomalies in the double-layered items of laundry (10) caused by the foreign objects are detected from the outside without contact. Method according to Claim 1, characterized in that such anomalies are determined which cause one or possibly also several topographical anomalies (26) on at least one outside (25, 35) of the respective double-layered item of laundry (10), for example bulges, bulges or the like . Method according to Claim 1 or 2, characterized in that topographical anomalies (26) are determined by at least one scanning device by contactless external scanning, preferably full-area external scanning, of the double-layered laundry items (10). Method according to Claim 1 or 2, characterized in that anomalies caused by foreign objects in double-layered items of laundry (10) are detected by at least one imaging device (20, 21, 22, 23), preferably at least one camera, are determined without contact, preferably in that the at least one imaging device (20, 21, 22, 23) captures at least one outside (25, 35) of the respective double-layered item of laundry (10) and/or a lateral profile thereof and/or scanned. Method according to Claim 4, characterized in that anomalies are determined by at least one imaging device (20, 21, 22, 23) in the case of a double-layered item of laundry (10) which is illuminated and/or transilluminated from one side. Method according to one of the preceding claims, characterized in that anomalies caused by foreign objects in double-layered items of laundry (10) are determined in the case of hanging double-layered items of laundry (10), in particular hanging in a spread out manner. Method according to one of Claims 1 to 5, characterized in that anomalies caused by foreign objects are determined when the double-layered items of laundry (10) are lying flat, preferably when the double-layered items of laundry (10) are lying flat and/or spread out. Method according to one of the preceding claims, characterized in that each double-layered item of laundry (10) is individually checked without contact to determine whether it has at least one anomaly caused by at least one foreign object in the double-layered item of laundry (10). Method according to one of the preceding claims, characterized in that the contactless determination of the anomaly caused by at least one foreign object in the respective double-layered item of laundry (10) takes place before the mangle and/or before the double-layered item of laundry (10) is folded. Method according to one of the preceding claims, characterized in that distance values determined without contact by at least one distance measuring device on at least one outer side (25, 35) of the respective double-layered item of laundry (10) are automatically evaluated by a computer, for example, and if at least one topographical anomaly (26) is detected a double-layered item of laundry (10) this double-layered item of laundry (10) none is subjected to subsequent treatment, in particular is neither mangle nor folded or at least not folded. Method according to one of Claims 1 to 9, characterized in that the at least one imaging device (20, 21, 22 and/or 23) detects images, image data sets, differences in brightness and/or humidity differences of at least one outside ( 25, 35) of the respective double-layered item of laundry (10) are evaluated automatically, for example by an image evaluation device, a light-sensitive evaluation device and/or a moisture-sensitive evaluation device, and if at least one anomaly is detected, in particular an elevation, a shadow and/or a damp spot, this double-layered item of laundry (10) is neither mangled nor folded or at least not folded.

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