Improved apparatus for the inspection of leather

Abstract

It is herein disclosed an apparatus (1) for the inspection of material (M), in particular leather, having a work plane (2) adapted to provide a support plane for the material (M), a control unit (C) adapted to manage the apparatus (1), a lighting system (15) adapted to lighten the material (M) on the work plane (2), and at least one image detector (30) adapted to capture images of the material (M) on the work plane (2). The control unit (C) is configured to process the images captured by the image detector (30) and to generate a digital copy of the inspected material (M), wherein the apparatus (1) further comprises stretching means (10) configured to exert a stretching on the material (M) arranged on the work plane (2), so as to identify defects even on the material (M) under stretching.

Description

[0001] Title: Improved Apparatus for the inspection of leather

[0002] DESCRIPTION

[0003] Field of application

[0004] The present invention relates to an apparatus for the inspection of materials, in particular for the inspection of leather for several hide goods, clothing, footwear, automotive and the like, and the following description is made with reference to this application field with the only purpose of simplifying the exposition thereof.

[0005] Prior art

[0006] As it is well known in this technical field, there exist inspection apparatuses onto which the leather to be inspected is arranged prior to the subsequent processing thereof. During the inspection, the leather arranged on these apparatuses are analysed by the operator in order to detect and mark all of the defects present.

[0007] Indeed, each type of leather, even of the best quality, may have superficial defects, such as small stains, superficial alterations, low quality areas and the like. For this reason, as part of quality control, it is important to identify and report all possible defects before subsequent processing.

[0008] In these apparatuses, not all defects are easily identifiable on the leather without prior stretching the same, so often stretching is carried out on the leather before proceeding with the identification and reporting of the various defects.

[0009] The technical problem of the present invention is to provide an apparatus having structural and functional features, so as to allow overcoming the limitations and drawbacks still affecting the known solutions, in particular an apparatus that allows an improved inspection.

[0010] Summary of the invention The solution idea underlying the present invention is to provide an apparatus able to create a digital copy of the leather arranged on the work plane and also to exert a stretching on said leather, so as to identify all defects and report them, once identified, in said digital copy and / or in a proper report.

[0011] Based on said solution idea, the above technical problem is solved by an apparatus for the inspection of material, in particular leather, comprising a work plane adapted to provide a support plane for the material, a control unit adapted to manage the apparatus, and at least one image detector adapted to capture images of the material on the work plane, wherein the control unit is configured to process the images captured by the image detector and to generate a digital copy of the material inspected, further comprising stretching means configured to exert a stretching on the material arranged on the work plane, so as to identify defects even on the material under stretching.

[0012] Via said applied stretching, the stretching means are configured to perform an overall lengthening of the material under inspection. In other words, the stretching results in the overall lengthening (by small amount) of the material under inspection; in this way, the action of the stretching means results in the overall lengthening of the material that ensures an efficient analysis (in particular when said material is digitalized) .

[0013] More particularly, the invention comprises the following additional and optional characteristics, taken individually or in combination if required. Said optional characteristics are defined in the dependent claims.

[0014] According to an aspect of the present application, the stretching means may be configured to exert said stretching by moving at least one moving side (or moving portion) of the work plane, which comprises a fixed portion and said at least one moving side or moving portion that can be moved away from the fixed portion.

[0015] In particular, according to an aspect of the present invention, the stretching means may comprise a first rod associated with a first side of the work plane, wherein said first rod is configured to move away from and toward the first side del work plane and is configured to abut onto said first side, so as to hold a first portion of the material to be inspected between said first rod and said first side.

[0016] According to an aspect of the present invention, the stretching means may comprise a second rod and a third rod coupled to each other and associated with a second side, opposite the first side, of the work plane, wherein the second rod and the third rod are movable with respect to each other, so as to house a second portion of the material to be inspected and to hold said second portion therebetween, and wherein said second rod and said third rod are configured to move together in close abutment (i.e. in their configuration of maximum mutual approach in which for instance they hold the material) away from and toward the second side.

[0017] According to an aspect of the present invention, when the first portion of the material to be inspected is held between the first rod and the first side of the work plane, and when the second portion of the material to be inspected is held between the second rod and the third rod, the movement of the second rod and of the third rod (integral movement in close abutment) away from the second side of the work plane causes the stretching on said material.

[0018] According to an aspect of the present invention, the first rod, the second rod and the third rod may be moved by motorized means.

[0019] According to an aspect of the present invention, the apparatus may further comprise a signaling element adapted to indicate defects on the surface of the material to be inspected, wherein said signaling element is provided with a lighting element adapted to be detected by the image detector, the coordinates of the movement of said lighting element being calculated by said control unit, and wherein said control unit is configured to recognize the position, and / or shape, and / or entity of the defect of the material surface based on said coordinates of the movement of the lighting element.

[0020] According to an aspect of the present invention, the control unit may be configured to automatically carry out an adjustment of the position of the defects which are detected and present in the captured images when the stretching means exert the stretching on the material, the entity of said adjustment varying according to the position of the defect with respect to the work plane taken as reference.

[0021] According to an aspect of the present invention, the control unit may be configured to calculate a deformation undergone by the material due to the stretching exerted by the stretching means and to establish, based on the calculated deformation, the actual position of the defects identified and present in the captured images when the material is under stretching.

[0022] According to an advantageous aspect of the present invention, the control unit may be configured to recognise and define, based on one or more references on the material which are visible in the captured images by the image detector, a displacement of said material on the work plane made by the operator, and to create the digital copy of the material taking into account said displacement by joining a plurality of captured images.

[0023] For instance, the reference may be the peripheral profile of the material as detected by the image detector.

[0024] According to an aspect of the present invention, the work plane may be made of an at least partially transparent material.

[0025] In this case, the apparatus may comprise at least one further image detector configured to capture images of the surface of the material facing toward the work plane, said further image detector being opposite the at least one image detector with reference to the work plane.

[0026] According to an aspect of the present invention, the apparatus may comprise a projector adapted to project information, such as for instance the position and / or profile, relating to the identified defect, on the material, in order to provide a feedback to the operator.

[0027] According to an aspect of the present invention, the apparatus may comprise suction (aspiration) means arranged at least along the peripheral edge of the work plane adapted to hold the material to be inspected.

[0028] According to an aspect of the present invention, the control unit may comprise different operating instructions stored therein, said different operating instructions corresponding to different stretching values applicable by the stretching means.

[0029] According to an aspect of the present invention, the control unit may be configured to allow the selection of an operating instruction among said operating instructions and to control the stretching means based on the selected operating instruction, applying a specific desired stretching.

[0030] According to an aspect of the present invention, the different operating instructions may correspond to different values (e.g., distance values) of the second rod and third rod away from the work plane.

[0031] According to an aspect of the present invention, the control unit may be configured to automatically detect the defects on the material based on the content of the images captured by the image detector.

[0032] According to an aspect of the present invention, the work plane may comprise at least one first pair of opposite sides and at least one second pair of opposite sides, said work plane being preferably rectangularshaped.

[0033] According to an aspect of the present invention, the apparatus may comprise a lighting system adapted to lighten the material on the work plane, wherein said lighting system comprises a first set of light sources arranged and configured to lighten the work plane from an elevated position with respect to said work plane, according to a first incidence angle with said work plane, and a second set of light sources arranged and configured to emit grazing light to the work plane, according to a second set of light sources with said work plane, said second incidence angle being smaller than the first incidence angle.

[0034] According to an aspect of the present invention, the second set of light sources may comprise a first plurality of light sources arranged at at least one of the two opposite sides of the first pair of opposite sides, and a second plurality of light sources arranged at at least one of the two opposite sides of the second pair of opposite sides.

[0035] According to an aspect of the present invention, the control unit may comprise a memory unit including a plurality of operating instructions, each operating instruction corresponding to a lighting mode of said lighting system, and wherein said apparatus further comprises means configured to allow the selection of a lighting mode among said stored lighting modes, said control unit being configured to control the lighting system based on said selection.

[0036] According to an aspect of the present invention, the control unit may be configured to allow the selective activation of one of the first set of light sources and of the second set of light sources.

[0037] According to an aspect of the present invention, the control unit may be configured to adjust the relative intensity between said first set of light sources and said second set of light sources.

[0038] According to an aspect of the present invention, the work plane defines, through an area thereof, a work area, and said work plane may be extensible by moving at least one side thereof (or in general a portion thereof), so as to cause a variation of the work area. Once the work area has been adjusted, the movement mechanism itself may be also used to exert the stretching on the material (for instance, the same motor may be used both for the variation of the work area and to exert the stretching on the material); obviously different technical solutions may also be provided for moving the work area and for the stretching of the material (for instance the work area may be moved even manually or in continuous with a worm or snap screw with a series of holes, o in other suitable manner, and then the stretching is applied by moving the aforementioned rods or the rear roll as it will be discussed herein after).

[0039] According to an aspect of the present invention, the work plane may comprise a conveyor belt configured to move the material arranged thereon.

[0040] According to an aspect of the present invention, the conveyor belt may comprise at least one first roll at a first side of the work plane, and a second roll at a second side of the work plane, wherein the second roll is movable, so as to cause the movement of the second side of the work plane.

[0041] According to an aspect of the present invention, the apparatus may comprise a first rod associated with the first side of the work plane, wherein the first rod is configured to move away from and toward said first side of the work plane and is configured to abut onto said first side, so as to hold a first portion of the material to be inspected between said first rod and said first side and a second rod configured to move away from and toward the second side of the work plane, so as to hold a second portion of the material to be inspected.

[0042] According to an aspect of the present invention, the second rod and the second roll may be configured to move integrally during the movement of the second side of the work plane.

[0043] The features and advantages of the apparatus according to the invention will become apparent from the following description of an embodiment thereof, given by way of non-limiting example with reference to the accompanying drawings.

[0044] Brief description of the drawings In those drawings:

[0045] - figure 1 shows a schematic perspective view of an apparatus according to the present invention;

[0046] - figure 2A shows a detail of a work plane and of stretching means according to an embodiment of the present invention;

[0047] - figure 2B shows a detail of a work plane and of stretching means according to an embodiment of the present invention, in a configuration in which said stretching means exert a stretching on a material to be inspected;

[0048] - figure 3 shows a detail of the apparatus according to an embodiment of the present invention;

[0049] - figure 4 shows an example of virtual division of a material into several work areas; and

[0050] - figures 5A and 5B show a detail of the apparatus according to another embodiment of the present invention, in different operating configurations.

[0051] Detailed description

[0052] With reference to those figures, an apparatus (or machine) for the inspection of materials, in particular leather, according to the present invention is globally and schematically indicated with reference number 1.

[0053] It is worth noting that the figures represent schematic views and are not drawn to scale, but instead they are drawn, so as to emphasize the important features of the invention. Moreover, in the figures, the different elements are depicted schematically, their shape varying depending on the desired application. It is also noted that in the figures the same reference numbers relate to elements that are identical in shape or function. Finally, particular features described in relation to an embodiment illustrated in a figure are also applicable to the other embodiments illustrated in the other figures.

[0054] It is also noted that, unless expressly indicated, the process steps can also be reversed if necessary.

[0055] Furthermore, positional references used in the present description, comprising indications such as lower or upper, below or above, or similar phrases, are always referred to the operating configuration represented in the figures, and they must in no case be assigned a limiting value. In any case, said references, when referred to the components of the apparatus of the present invention in the operating position, are used in practice by a person skilled in the art.

[0056] To facilitate the following description of the apparatus 1, two orthogonal directions are identified by way of example: an Y direction and an X direction.

[0057] The apparatus 1 is a machine for the inspection of materials (generically indicated herein with reference M), in particular leather for the production of clothing items, hide goods, footwear, automotive, furniture and the like. The apparatus 1 is thus preferably suitable for the inspection of leather material, even though other materials (for different applications) are possible.

[0058] Obviously, in the context of the present invention, the term “sheet” means any element of any shape and material (in particular leather) and substantially two-dimensional in size, having a certain thickness (generally reduced), that must be inspected / processed by the apparatus 1, even unrolled from a roll. In general, said material is also indicated as plane material, without obviously limiting the shape or composition thereof.

[0059] In general, the apparatus 1 comprises a control unit C, including a proper memory unit (indicated with reference MEM) and suitably programmed and arranged for the management and automatic control thereof. The control unit C may be for instance a computerized unit integrated or external to the apparatus 1 and operatively connected thereto. Furthermore, it is noted that the control unit C may be a single control unit or may comprise a plurality of local and / or remote units. The control unit C is thus able to control the apparatus 1 to obtain the automated operation thereof. In any case, the present invention is in no way limited by the architecture used for the control unit C, which in general may be any appropriate computerized unit, comprising one or more units (possibly also including components for the interaction with the operator, such as screens, buttons and the like) arranged in any manner according to the needs and / or circumstances. Moreover, it is noted that, in the context of the present invention, means of selection and user interaction may also be considered as part of the control unit C.

[0060] As illustrated in figure 1, the apparatus 1 of the present invention comprises a work plane 2 (also called worktable) adapted to provide a support plane (indicated with reference a) for the material M to be inspected. The work plane 2 preferably has a quadrangular plan (even more preferably rectangular), even if it is not limited by a particular shape.

[0061] In general, the term work plane 2, as known in the field, indicates the structure that supports the sheet of material to be cut, said plane being preferably provided with at least two opposite sides of greater extension 2a’ and 2a” and at least two opposite sides of smaller extension 2b’ and 2b” (i.e. a first pair of opposite sides and a second pair of opposite sides, even more preferably rectangular or at least defining a rectangular work surface), and having a certain thickness, the term side thus indicating a portion of lateral edge of the work plane. Obviously, though the rectangular shape is preferred, other shapes are not excluded, in which two opposite greater sides and two smaller opposite sides (for instance trapezoidal, or even with more than four sides) are present. Squared shapes are not even excluded, in any case having two pairs of opposite sides, wherein the sides of the first pair of opposite sides are adjacent to the sides of the second pair of opposite sides.

[0062] In use, the operator positions himself at a side of the work plane 2 free from obstructions, for instance one of the sides of greater extension.

[0063] In case of a rectangular- shaped work plane 2, as shown in the figures, the Y direction (transversal direction of the work plane 2) is parallel to its minor sides, whereas the X direction (longitudinal direction of the work plane 2) is parallel to its major sides.

[0064] The apparatus 1 is provided with a base 5, for instance box-shaped, which represents the support for the work plane 2 and possibly encloses mechanical and electronical elements to assist the apparatus 1, as well as it can be provided with a control panel 12 for entering commands.

[0065] As previously mentioned, the apparatus 1 is an inspection machine comprising at least one image detector (preferably a plurality of image detectors, herein indicated with reference 30) adapted to capture images (and possibly even videos) of the material M on the work plane 2.

[0066] Suitably, the control unit C is configured to process the images captured by the image detectors 30 and to generate a digital copy of the inspected material M based on said captured images (and thus substantially to digitize the leather to be analysed). Each image detector 30 is thus adapted to capture a series of images, one after the other, even after a displacement of the leather made by the operator in the various steps of the inspection, so as to be able to generate a digital image of the entire fabric by overlapping the different captured images.

[0067] In other words, the control unit C is configured to receive the captured image data (for instance in a continuous manner) from the image detectors 30, said image data being joined and overlapped by the control unit C, so as to obtain a complete image of the fabric starting from the data provided by the image detectors 30, thus a file (for instance a single file .pdf) is created containing a high resolution image of the surface of the leather to be inspected (i.e. the aforementioned digital copy). The control unit C is operatively connected to the memory unit MEM, which is configured to store at least one digitized image of the inspected fabric, as well as the report generated relatively to the inspected leather (as it will be discussed hereinafter). In this way it is possible to maintain a digital track of the inspection carried out, making the generated report available to multiple users in a simple way. In this regard, in an embodiment of the present invention, the memory unit is a cloud unit which a user may access remotely through a specific application and / or a specific address. The captured images are thus saved on a server which a user can access, through a device such as a PC or a smartphone, by connecting to an Internet address or launching a dedicated application installed in his / her device. The apparatus 1 of the present invention thus allows a digital storing of the inspected fabric, making the digitized image and report available to multiple users, such as for instance the fabric manufacturer or the firm that intends to carry out specific processing on said fabric. It is thus clear that this system makes any disputes with the fabric manufacturer regarding its quality much easier, since it is possible to access remotely, for instance through the cloud, the saved image to view said fabric and the report therewith associated. Obviously, it is also possible to locally save said information in a memory unit integrated in the control unit C. The digitization of the fabric and its online storing is particularly advantageous since, in addition to facilitating the disputes, it also allows pricing to be carried out precisely, as well as automating a possible future cutting step (thus avoiding having to digitize the fabric again) .

[0068] Advantageously according to the present invention, the apparatus 1 comprises stretching means (generally indicated with reference 10) configured to exert a stretching (or even traction) on the material M arranged on the work plane 2, so as to identify defects even on said material M under stretching. In this way, the material M is suitably stretched by the stretching means 10 prior to the inspection thereof, in order to make visible even those defects that would otherwise not be identifiable, and to possibly report said defects in the digital copy of the material M and / or in a proper report.

[0069] Suitably, via said stretching, the stretching means are configured to perform an overall lengthening of the material under inspection. In other words, the stretching operation results in an overall lengthening of the material under inspection; in this way, the action of the stretching means results in the overall lengthening of the material that ensures an efficient analysis, in particular when said material is digitalized. Therefore, the apparatus 1 of the present invention is able not only to perform a local elimination of the creases of the material M, but a lengthening of said material M.

[0070] In an embodiment, the leather under stretching is photographed by the image detectors 30 and digitized, whereas in other embodiments this is not necessarily done and just the leather not under stretching is digitized.

[0071] The stretching means 10 are associated with the work plane 2.

[0072] In general, the stretching means are configured to exert said stretching by moving at least one moving side (or moving portion) of the work plane 2; in the case, the work plane 2 comprises a fixed portion and the above mentioned moving side or moving portion, to which a portion of the material M is associated and which can be moved away from said fixed portion, causing the stretching of the material. Said moving side may thus be part of the stretching means.

[0073] As mentioned, the stretching means 10 are associated with the work plane 2. In particular, in an advantageous embodiment illustrated in figures 2A and 2B, the stretching means 10 comprise a series of rods whose movement with respect to the work plane 2 causes the aforementioned stretching.

[0074] More particularly, in this embodiment, the stretching means 10 comprise a first rod 10a associated with a first side 2a’ of the work plane 2, wherein said first rod 10a is configured to move away from and toward said first side 2a’ of the work plane 2 and is configured to abut onto said first side 2a’, so as to hold a first portion M’ of the material M to be inspected when said first portion M’ is arranged between it and the aforementioned first side 2a’.

[0075] There are also a second rod 10b and a third rod 10c coupled to each other and associated with a second side 2a”, opposite the first side 2a’, of the work plane 2. The second rod 10b and the third rod 10c are movable with respect to each other, so as to house a second portion M” of the material M to be inspected and to hold said second portion M” therebetween when said rods are in the configuration of maximum mutual approach (abutting onto each other). The second rod 10b and the third rod 10c are configured to move together in close abutment, i.e. integrally against each other (or in general to move together in the condition of maximum mutual approach), away from and toward the second side 2a” of the work plane 2.

[0076] The first rod, as well as the second and third rods, thus work like pliers for holding portions of material.

[0077] More particularly, when the first portion M’ of the material M to be inspected is held between the first rod 10a and the first side 2a’ of the work plane 2, and contextually the second portion M” of said material M is held between the second rod 10b and the third rod 10c, the movement of said second rod 10b and of said third rod 10c (which, as previously seen, move together in close abutment) away from the second side 2a” of the work plane 2 causes the stretching on said material M, as illustrated in figure 2B.

[0078] In an embodiment, the first rod 10a moves away from the work plane 2 by a distance up to 100 mm (this opening is useful to insert new leather, to make the leather move forward - from a portion to the subsequent one - and to remove the leather at the end of the digitization). Instead, the second and third rods 10b and 10c have a maximum mutual distancing of 195 mm (this opening is useful to insert new leather, to make the leather move forward - from a portion to the subsequent one - and to remove the leather at the end of the digitization). When said rods are closed one against the other, they move together in close abutment away from the work plane 2 up to 195 mm (distance corresponding to the maximum stretching on the leather). Obviously the stretching value required for the leather may vary from project to project, from client to client, etc. and can be selected as it will be discussed herein after, and thus the distancing may vary (for instance it can be smaller than what indicated above).

[0079] Furthermore, it is noted that the aforementioned stretching means 10 may be applied to an apparatus as the one described above, however without necessarily comprising the image detectors and implement the digitization of the material M.

[0080] In an embodiment, the aforementioned rods are moved by the motorized means 10m and worm screws, even if other movement modes may also be provided and fall within the scope of the present invention.

[0081] In an embodiment, the movement of the rods is a translation movement in a direction parallel to the plane where the work plane 2 lies, i.e. a translation on said plane.

[0082] Furthermore, in an embodiment, one or more of the aforementioned rods may be provided, at one of its abutment face, with a layer of material having lower rigidity, for instance rubber, in order to reduce the risk of damaging the material M during the stretching thereof.

[0083] In general, the material is digitalized when stretched, even if it can be digitalized also when not stretched. Suitably, the control unit C is able to perform the digitalization of the whole surface of the material M and not only locally.

[0084] When the material M is in the stretching state, there are various modes to mark the defects identified by the operator thereon. In an embodiment of the present invention, the apparatus 1 may comprise a signaling element (indicated with reference 40) with which the operator may indicate the defects on the surface of the material M. For instance, the signaling element 40 may be provided with a lighting element able to be detected by the image detectors 30, the coordinates of the movement of said lighting element being calculated by the control unit C; in this way, the control unit C is configured to recognise the position, and / or shape, and / or entity of the defect of the material M surface based on the coordinates of the movement of the lighting element. Furthermore, instead of the lighting element, a radio, Bluetooth, wi-fi system, etc. may be present, able to send information to the control unit C.

[0085] The control unit C is then configured to correlate the defects on the fabric indicated by the signaling element 40 with the image captured by the leather, with possible generation of a report indicating at least the shape and position of the defects on said fabric.

[0086] Obviously, even other signaling modes are provided; for instance the operator may indicate the presence of a defect by means of a signaling chalk, or even by placing a label at the defect, or in any other suitable way. Should chalks be used, the defects are directly on the material to be inspected, afterwards images of the fabric are captured, said images being processed by the control unit C.

[0087] The coordinates of the pixels of the captured image are referred to a prefixed bidimensional reference system, based on which the coordinates of the signaled defects are calculated.

[0088] Furthermore, in an alternative embodiment of the present invention, the apparatus 1 is able to capture images of the fabric and the control unit C is configured to automatically detect, based on the captured images, the presence and position of possible defects, for instance by carrying out certain procedures based on machine learning, for instance exploiting neural networks.

[0089] However, it is noted that, when the stretching exerted on the material M is released, there is the need to identify the actual position of the defect on the material not under stretching. Indeed, it is noted that the stretching is not homogeneous for all material M, but it may vary according to the position of its various portions with respect to the work plane 2. For instance, a central portion of the leather, with the same amount of force exerted, may stretch more than its more lateral portions.

[0090] In order to solve this problem, the control unit C is suitably programmed to automatically carry out an adjustment of the position of the defects detected and present in the captured images when the stretching means 10 exert the stretching on the material M, the entity of said adjustment varying according to the position of the defect with respect to the work plane 2 taken as reference. In this way, based on where the defect is marked on the leather, the control unit C (by processing the captured image) is able to displace the position of the defect, virtually taking it back to the actual position it is in when the material M is not stretched, said displacement varying based on where the defect is. As above mentioned, the work plane 2 is taken as reference, and thus a reference system linked thereto is used. This correction carried out by the control unit C is thus a local correction, that takes into account the fact that some portions of the material M stretch more than others during the action of the stretching means 10.

[0091] The aforementioned correction is thus referred to the configuration in which the stretching means 10 do not exert the stretching on the material, and it corresponds to the difference of position of the defect in the configuration under stretching compared to the configuration not under stretching.

[0092] Furthermore, the control unit C is configured to calculate the deformation undergone by the material M due to the stretching exerted by the stretching means 10 and to establish, based on the calculated deformation, the actual position of the defects identified and present in the captured images when the material M is under stretching. Indeed, it is known that, once the stretching exerted on the material M is released, said material will not immediately return to the identical starting configuration, but it may take some time (and in some cases the deformation is not even perfectly elastic), and the control unit C is thus suitably programmed even to take into account this phenomenon.

[0093] In an embodiment, all of the aforementioned operations are carried out by the control unit C by executing artificial intelligence algorithms.

[0094] Moreover, the apparatus 1 is also equipped with a function able to keep track of the movements of the material M on the work plane 2, for instance when the operator moves said material M in order to inspect a new portion thereof.

[0095] More particularly, the control unit C is configured to recognise and define, based on one or more references on the material M visible in the captured images, a displacement of said material M on the work plane 2 made by the operator and, in creating the digital copy of said material M, it takes into account said displacement, combining the various captured images together for each positioning of the material M in the most appropriate way, so that said digital copy comprises the entire inspected material.

[0096] The references used to identify the displacement of the material (for instance its entity / direction with respect to the reference - i.e. with respect to the work plane) may be for instance the peripheral profile itself of the material, or it may be a label arranged on said material M. Preferably, the reference corresponding to the peripheral profile of the leather as detected by the image detector 30.

[0097] In an embodiment, the image detectors 30 continuously capture images of the leather while it is displaced, in order to carry out a virtual tracking of the displacement. In any case, there is always a certain overlap between one image and the next in order to recreate the digital copy of the leather correctly.

[0098] The control unit C may further be configured to define a plurality of cutting areas (also called quality areas) on the digitized image, wherein the type, number, and position of said cutting areas is defined and optimized based on the information captured by the control unit C during the inspection of the leather.

[0099] Furthermore, in an embodiment of the present invention, the work plane 2 is formed by at least one partially transparent material (for instance glass or Plexiglas or any other suitable material), so as to look therethrough. In this embodiment, the apparatus 1 also comprises at least one further image detector or lower detector (not illustrated in the figures, in particular a plurality of further image detectors) configured to capture images of the material M from below, i.e. images of the surface of the material M facing toward the work plane 2 (i.e. that surface in contact with the work plane). The further image detector is thus opposite the upper image detectors 30 with reference to said work plane 2, so as to carry out a complete inspection of the material M. In particular, the presence of the transparent work plane 2 also allows identifying areas of the leather with important structural defects which are not visible on the other face of the leather but which can impact the quality of the final product. The lower detector is connected to a screen 35 which allows viewing the lower surface of the leather.

[0100] Moreover, there is a projector 20 adapted to project information (see for instance figure 3), such as for instance the position and / or profile relatively to the identified defect, on the material M, in order to provide a feedback to the operator. In an embodiment, the projector 20 is a laser projector.

[0101] There is also the possibility to indicate, through the projector 20, on the material M, the position of the defects which are displayed by the lower image detector, for instance by selecting the defect to be indicated on the aforementioned screen, so as to analyse the impact of said defect on the upper surface of the leather.

[0102] Furthermore, in an embodiment of the present invention, suction means are present, for instance arranged along the peripheral edge of the work plane 2 and adapted to hold the material M to be inspected.

[0103] In an embodiment, the work plane 2 may possibly be tilted if needed by proper lifting means.

[0104] Furthermore, in an embodiment, the control unit C comprises different stored operating instructions (for instance stored in the memory unit MEM) which correspond to different stretching values applicable by the stretching means 10; in this way the control unit C is configured to allow the selection of an operating instruction among the various operating instructions and to control the stretching means 10 based on said selected operating instruction, by applying a specific desired stretching. The aforementioned different operating instructions correspond to different values of the second rod 10b and third rod 10c away from the work plane 2. This is useful since, based on the type of leather and / or particular application, a different stretching of the leather may be required.

[0105] As illustrated in the figures, the apparatus 1 further comprises a lighting system 15 adapted to lighten the work plane 2, in particular the material M arranged on said work plane 2.

[0106] Moreover, it is noted that, in this embodiment, the control unit C may also be divided into two separate control units, one for lighting management and one for defect management, but obviously the present invention is not limited thereto and many other embodiments are possible, for instance it is possible to provide for a single computerized unit.

[0107] In a preferred embodiment of the present invention, the lighting system 15 comprises at least one first set of light sources (identified with reference 15’ and called for the sake of simplicity “upper lights 15’”), which are arranged and configured to lighten the work plane 2 from above, i.e. from an elevated position with respect to said work plane 2, and a second set of light sources (identified with reference 15” and also called for the sake of simplicity “grazing lights 15””), which are arranged and configured to emit grazing light to the work plane 2, i.e. with grazing incidence.

[0108] As for the upper lights 15’, as it will also be illustrated herein after, they are arranged on a support that is located above the work plane 2 (for instance, so as to lie on a plane that is located above said work plane 2 and possibly parallel thereto), and thus they are configured to lighten the work plane 2 from an elevated position with respect thereto, according to a first incidence angle with said work plane 2, preferably, but not limitedly, of 90° (for instance an angle comprised between 70° and 110°), such as to ensure a homogeneous lighting from above of the work plane).

[0109] Furthermore, the term “grazing lights 15”” is used herein, and as known in the field, to indicate a set of light sources that emit incident beams with a small angle with respect to the work plane 2, very smaller than the incidence angle of the upper lights 15’, for instance an angle from 0° (parallel light) to 30°, without however limiting to a particular angle value. Even a negative angle value, for instance from -30° to 0°, falls within the definition of grazing light according to the present invention; the important thing is that the incidence angle is such as to ensure the desired grazing. Said grazing lights 15” are arranged at a reduced height from the plane, for instance at few centimeters from said work plane 2, whereas the upper lights 15’ are arranged at a much greater height, even more than one meter.

[0110] In an embodiment of the present invention, the grazing lights 15” are a set of lights that includes a first plurality of light sources (indicated with reference number 15”a) arranged at one of the two opposite sides of greater stretching (the side 2a” of the figures), in particular at the side opposite the one in which the operator works, said lights being also indicated as horizontal lights or frontal lights. Suitably, there is also a second plurality of light sources (indicated with reference number 15”b) arranged at at least one of the two opposite sides of lesser stretching 2b, preferably (but not necessarily) at both said minor sides, said lights being also indicated as lateral lights.

[0111] All this is advantageous since some types of defects can only be detected by the lights arranged sideways, i.e. on the minor sides of the work plane, whereas other types of defects (i.e. the defects orientated differently) are only detectable with lights arranged on the side of greater stretching, i.e. in general on the side opposite the one in which the operator is present.

[0112] In the case of a quadrangular plan, the first plurality of light sources 15”a is arranged at the side opposite the one in which the operator is present and the second plurality of light sources 15”b is arranged at at least one of the sides adjacent said side opposite the operator (lateral lights).

[0113] The second plurality of light sources 15”b is focused to lighten far away, for instance up to 1.5 m, and may comprise light sources arranged on various substantially parallel rows, and thus at different heights to lighten far away, maintaining a proper grazing angle. In an embodiment, light sources arranged on one row are configured to generate a light beam having an incidence angle with the work plane 2 that is different from the one of light sources arranged on another row.

[0114] In general, each light source may be set with an own specific intensity and may be oriented, so as to have an own specific incidence angle. Obviously the invention is not limited to a particular arrangement and combination of grazing angles and many other configurations are possible.

[0115] In an embodiment, it is possible to adjust the relative intensity (and / or possibly the colour temperature) between the first plurality of grazing light sources 15”a and the second plurality of grazing light sources 15”b: for instance, to identify the “vertical” defects (with reference to the plane 2), it may be appropriate to set the intensity of the second plurality of light sources 15”b (i.e. the lateral lights) to be greater than that of the first plurality of light sources 15”a (i.e. the frontal lights), whereas for the “horizontal” defects the opposite applies, taking into account that the effects of said different light sources, at the same intensity, cancel each other out. Obviously even other parameters of the light sources may be adjusted, such as for instance the colour temperature.

[0116] It is therefore possible to dim not only the grazing lights 15” with respect to the upper lights 15’ according to different values, but also to dim the different grazing lights relatively to each other, as above illustrated, with the great advantage of being able to easily detect any type of defect. Obviously it is also possible to provide for a case in which some light sources are totally off and others are on.

[0117] In an embodiment of the present invention, the grazing lights 15” are covered by a covering element and a heat sink is present to avoid an excessive overheating thereof.

[0118] In a preferred embodiment, the lighting system 15 comprises a plurality of LEDs whose emission properties are controllable, even if the lights of the apparatus 1 are not limited by a particular type.

[0119] The memory unit MEM includes a plurality of operating instructions, each operating instruction corresponding to a lighting mode of the lighting system 15. For instance, the various operating instructions may be related to particular intensities and / or colour temperatures of the light sources of the lighting system 15, also providing different relative intensities between the upper lights 15’ and the grazing lights 15”, for instance selectable based on the features of the material to be inspected, as it will be detailed hereinafter.

[0120] According to the present invention, the apparatus 1 comprises proper means configured to allow the selection of a lighting mode between the aforementioned stored lighting modes according to the needs, so that the control unit C is able to control the lighting system 15 automatically based on said selection.

[0121] In this way, the operator is able to choose the preferred lighting mode, by simply choosing among the various stored modes, for instance through a panel or any other selection means (which may be considered part of the control unit C) of the apparatus 1.

[0122] Obviously, in an embodiment, in addition to what seen above, a manual selection of the lighting mode by the operator is also possible, who may switch on / switch off / dim at will the lights of the lighting system 15.

[0123] In an exemplifying embodiment, the memory unit MEM comprises a plurality of previously stored instructions for a respective plurality of leather (for instance for leather of different colours or in general of different kind), each instruction corresponding to a specific lighting mode of the lighting system 15 adapted to the relevant leather and selectable through the control unit C, so that for each leather arranged on the work plane it is possible to select the most suitable configuration of lights, the control unit C automatically setting all parameters.

[0124] For instance, in a first lighting mode, the control unit C is configured to set a first intensity and / or colour temperature of the lighting system 15, and, in at least one second lighting mode, the control unit C is configured to set a second intensity and / or colour temperature of the lighting system 15 different from the first intensity and / or colour temperature.

[0125] In another example, in addition or alternatively, the control unit C is configured to allow the selective activation of one of the first set of light sources 15’ (i.e. the upper lights) and the second set of light sources 15” (i.e. the grazing lights), as well as it may be configured to adjust the relative intensity of said first set of light sources 15’ and said second set of light sources 15”, for instance defining a percentage of relative intensity between said two different light sources. Indeed, there may be situations in which the grazing lights 15” are not necessary and thus may be deactivated, or opposite situations in which the upper lights 15’ are not necessary. The possibility of adjusting the relative intensity between the upper lights 15’ and the grazing lights 15” is also very useful: for instance, if one wishes to identify a tiny defect, the grazing lights 15” will be predominant with respect to the upper lights 15’ whereas in other cases the upper lights 15’ will be predominant, and the operator is able to easily choose the most suitable lighting mode.

[0126] As illustrated in the figures, the lighting system 15, as well as the image detectors 30, are arranged on a proper support 9 which, in an example, has an open box shape at the side facing toward the operator, even if any suitable shape is comprised in the scope of the present invention. In the embodiment illustrated in the figures, the upper lights 15’ are arranged on the upper side of the support 9 whereas the grazing lights 15” are arranged on the lateral flanks and on the central vertical portion.

[0127] As previously seen, as for the grazing lights 15”, they are arranged at least along a greater side and / or along at least one of the two opposite minor sides of the work plane 2.

[0128] In an embodiment of the present invention, the grazing lights 15” comprise a plurality of light sources arranged side by side to each other and a plurality of respective lens configured to generate a light beam with a very small opening angle (in the example less than 45°, preferably between 5° and 25°). In general, light sources with a very small light beam opening (less than 45°) or even possibly provided with additional focusing lenses are used. This allows narrowing the emitted light beam a lot, wherein the various side by side light sources ensure a homogeneous lighting of the work plane 2, and an optimal maximum lighting distance is moreover ensured so that, as a whole, the side by side grazing lights substantially cover the entire work plane 2. In general, the lighting system 15 is configured so that the light be emitted homogeneously by a distance in a range 1 to 2 meters, preferably 1 meter and a half. In other words, the emission shape of the lenses associated with the grazing lights 15” is such that the light is emitted with a reduced opening angle and up to a distance of about one meter and a half, wherein the side along the work plane 2 is of about three meters and the short one is of about one meter and a half. As a result, the assembly of the plurality of side by side light sources (in particular LEDs) substantially covers the entire work plane 2 and allows excellent visibility. The control unit C is configured to allow the switching of the lighting system 15 at least between a first operating mode, which a lighting adapted to optimally allow the inspection of the fabrics by the operator corresponds to (and wherein no photograph of the leather is taken), and a second operating mode, which a lighting adapted to allow capturing images and / or videos by the aforementioned image detectors 30 corresponds to. In particular, by a suitable control, the user commands the control unit C to take a photograph of the leather (o more generally to pick up the leather on the work plane 2) and the control unit C is configured to adjust the lighting system 15 as a result (in a mode indicated in jargon as “technical light”), for instance lowering the light intensity to avoid the saturation of the detectors. The parameters of the detectors are stored in the memory unit MEM of the control unit C and are optimised (and fixed) based on the lighting chosen for the second operating mode in which the photograph is taken, said parameters being precisely applied to the image detectors 30 and no longer modified in the passage between the two different operating modes, since it is precisely the lighting system 15 which is consequently automatically adapted as a result.

[0129] In an embodiment of the present invention, the second operating mode is automatically activated when a proper command (such as for instance a pedal) which moves the work plane 2 is activated, with acquisition of images and the aforementioned video. Moreover it is noted that, in an embodiment, the video camera dedicated to capturing the video is one of the image detectors 30, which is temporarily used for the shooting of this video.

[0130] The management of the apparatus 1 by the user may occur for instance via the aforementioned control panel 12, provided with screen and keys, operatively connected with the control unit C (possibly, as previously mentioned, said panel may also be considered as part of the control unit C, for instance an end element thereof, by which the user may insert some inputs). Possibly the apparatus 1 may also be provided with the aforementioned screen 35 and control video cameras, said components being supported by the support 9.

[0131] In an advantageous embodiment of the present invention, the control unit C is configured to divide the work plane (and more particularly the material to be inspected) into different work areas Wa, and it is provided that the operator work from time to time in a single work area, which is displayed via the projector 20.

[0132] In particular, the control unit C is suitably configured (by executing steps of an appropriate algorithm) to define a plurality of work areas (identified with a same reference Wa) based on which the material M arranged on the work plane 2 is virtually divided. For instance, once the material M has been arranged on the work plane 2 and once the image has been captured (for instance through the image detectors 30, or even - less preferably - through dedicated detectors), said material M is virtually and automatically divided into a plurality of work areas (for instance three, even if any number falls within the scope of the present invention), as shown in the schematic example of figure 4, said work areas being then projected on the material, in particular each of them singularly, as indicated in the example of figure 4. Said areas may be the same or even different, the separation being carried out by the control unit C in the most suitable way.

[0133] As previously mentioned, in an embodiment, the projector 20 is configured to project the profiles Wap corresponding to the single work areas Wa separately from each other, i.e. they are not projected altogether but there is a selection of the profile to be projected; to this end, the apparatus 1, in particular the control unit C, is adapted to allow the passage of the projection of a profile to the projection of a different profile (for instance to a profile corresponding to an adjacent work area); this may occur automatically or even through manual selection of the user who chooses which profile to project, or even based on a movement of the material along a forward direction. It is thus noted that preferably single profiles are projected. For instance, each profile is projected at a certain work step, for instance based on the progress of the inspection by the operator. In an example, the operator selects the work area and the related profile is projected and, once the inspection has ended, the operation selects anther work area and the previously selected work area is indicated as already inspected, so as not to inspect already inspected areas. Clearly, the selection of the work areas may occur even automatically, based on a preset work sequence.

[0134] In an embodiment, if desired, all profiles may also be projected together.

[0135] Suitably, in an embodiment, the control unit C is configured to control the lighting system 15 based on the specific projected profile Wap. For instance, the control unit C may be programmed to control the lighting system 15 in order to keep the light sources of the lighting system 15 corresponding to non-projected work areas turned off or with reduced intensity (for instance close to the non-selected work area, by means of a correspondence defined by the control unit C), and thus only lighten the work area Wa of interest in a suitable manner.

[0136] In an embodiment of the present invention, the projected profiles Wap are square or rectangular-shaped, even if any suitable shape falls within the scope of the present invention.

[0137] It is thus noted that the term “profile” does not necessarily indicate a closed shape, but even a simple line falls within the meaning of this term.

[0138] Now, with reference to figures 5A and 5B, in an embodiment of the present invention, the work plane 2 comprises a conveyor belt 50 configured to move the material M arranged thereon, so as to carry out a no longer manual movement of the material M. In this case, the conveyor belt 50 itself forms the work plane 2, wherein a side del conveyor belt 50 corresponds to the first side 2a’ of the work plane 2 (i.e. the side closer to the operator) and an opposite side corresponds to the second side 2a” of the work plane 2 (i.e. the side opposite the side in which there is the operator) .

[0139] In this case, it is no longer necessary for the control unit C to be configured to recognise and define, based on one or more references on the material M (for instance based on the peripheral profile of the material), a displacement of said material on the work plane 2 carried out by the operator, since the movement of the conveyor belt 50 acts itself as a reference to detect the displacement of the material 50 (indeed, there may be an appropriate reference on the belt - the so-called tachymetric line - or the movement of the belt is kept track) .

[0140] Furthermore, the conveyor belt 50 comprises at least one first roll 50r’ at the first side 2a’ of the work plane 2 and a second roll 50r” at the second side 2a” of the work plane 2. It is noted that, in the context of the present invention, the term “conveyor belt” indicates the assembly of rolls and belt movable about said rolls, without however limiting the scope of the present invention.

[0141] Then there may be further rolls / pulleys configured to create an appropriate belt return system (as it will be detailed hereinafter), even if the present invention is not limited by the particular configuration of the conveyor belt.

[0142] In a first embodiment, all of the aspects discussed above relating to the stretching means 10 remain unchanged; for instance, the presence and operation of the rods 10a, 10b, and 10c, as well as all of the other aspects, are still valid with the necessary precautions (for instance, in the case of the rods, they will have a face with curved profile, so as to couple in abutment against the rolls), and thus this first embodiment is different from what seen above just in the presence of the conveyor belt 50, which solves the problem of the transport of the material M and of the automatic recognition of the new position after the displacement thereof.

[0143] In another embodiment of the present invention, the second roll 50r” (i.e. the roll that is furthest from the side in which the operator is present) is movable, so as to cause the movement of the second side 2a” of the work plane 2, in particular it is able to translate along a direction corresponding to the movement direction of the material on the belt (translation in the plane).

[0144] In this particular case, a first rod 10a’ associated with the first side 2a’ of the work plane 2 is present, wherein said first rod 10a’ is configured to move away from and toward said first side 2a’ of the work plane 2 (i.e. toward the first roll 50r’) and is configured to abut against the first side 2a’, so as to hold a first portion of the material M to be inspected between said first rod 10a’ and the first side 2a’ (analogously to the previously discussed first rod 10a). A second rod 10b’ configured to move away from and toward the second side 2a” (i.e. toward the second roll 50r”) is also present, so as to hold a second portion of the material M to be inspected. The second rod 10b’ and the second roll 50r” are configured to move integrally (i.e., during the movement of the second side 2a” of the work plane 2, said components - in the position of maximum mutual approach - move together), so that said movement causes the stretching of the material M.

[0145] In this embodiment, a third rod 10c’ connected and integral to the second roll 50r” is also present, so that the belt slide between the second roll 50r” and a side of said third rod 10c’ (indeed, a suitable passage for the belt is created), and so that the material be held between a side opposite said third rod 10c’ and the second rod 10b’ (in this case two movable pliers are therefore present - i.e. the pliers 10a’ and 10b’ - and a fixed plier that moves together with the second roll - i.e. the plier 10c’). In other words, in this case, when the material is held between the movable second rod 10b’ and the fixed third rod 10c’, the translation of the second roll 50r” and of the third rod 10c’ causes the stretching of the material.

[0146] In this embodiment, the rods 10a’, 10b’, and 10c’, as well as the second roll 50r”, are thus part of the stretching means 10 which cause the stretching of the material M arranged on the work plane 2. This embodiment is advantageous since, in addition to the above indicated advantages (i.e. the solution to the problem of transporting the material M and of the automatic recognition of the new position after the displacement thereof), there is also the chance to modify the work area identified by the work plane 2: indeed the movement of the second roll 50r” modifies the extension of the work plane 2, which thus may be adapted to differently sized leather. In case of small-sized leather, the second roll 50r” may not be in an extended position, or it may be only slightly translated (figure 5A), whereas for large-sized leather it is possible to carry out a greater translation of said second roll 50r”, thus advantageously increasing the work area (figure 5B). Basically, it is thus possible to modify the work area, by adapting it to the various dimensions of different leather to be inspected, as well as it is possible to exert the stretching on the material, still through the same mechanism; for instance at first it is possible to adjust the work area through the second roll 50r” and, once the material M has been arranged, it is then possible to carry out a further movement of said second roll 50r” for the stretching of said material M.

[0147] Additionally, this embodiment allows avoiding, during the separation movement of the second roll 50r” and thus of the second side 2a”, the formation of slots in which the material (such as for instance the slot G of figure 2A which opens between the side 2a” and the rod 10b) may end up, since the presence of the belt itself covers said slot, without the need for special precautions such as the use of curtains or similar. In other words, this embodiment solves the problem of the slot between the rear pliers and the work plane 2, and meanwhile allows modifying the work area, as described above.

[0148] Moreover, it should be noted that, in this embodiment, there is the further advantage due to the easier insertion of the leather: it is in fact possible to initially reduce the work area a lot (i.e. to retract the second roll without moving the rod lObj to facilitate the insertion of the leather.

[0149] The second roll 50r” and the rod 10b’ may be arranged on a same guide (for instance two side struts or members may be provided), but they can have an independent movement precisely to obtain the aforementioned advantages.

[0150] Furthermore, in order to always maintain a proper stretching of the belt, a system of pulleys 50p, in combination with a further element 50e (for instance cylindrical- shaped) configured to always maintain a proper stretching on said belt, is present. In this way, the total development of the conveyor belt is identical both in the case of figure 5A and in the case of figure 5B, where it is always under stretching and the formation of depressions where the material can fall is avoided. It is thus possible to stretch the material without causing a stretching of the belt, while being able to cleverly increase the work area.

[0151] Furthermore, it is noted that the chance to adapt the work area is also applicable to embodiments that do not include the conveyor belt. For instance, in an embodiment of the present invention, the work plane 2 is fixed, but it is extendable through the movement (translation in the plane a) of one of the sides thereof, in particular of the side 2a”.

[0152] Various modes for the extension of the work plane 2 may be implemented, for instance, with reference to figure 2A, it is possible to use the rod 10b (or more generally a movable portion that moves with respect to a fixed portion of the table) that is able to move independently of the rod 10c, the rod 10b corresponding in this case to the side 2a” of the work plane 2, with the presence of means configured to close the slot that is formed between the rod 10b and the fixed body of the work plane 2 (such as for instance a suitable curtain) . Alternatively, a telescopic worktable 2 with an extendable portion may be provided, without the need to use the rod 10b (in this second case the operation is similar to what was seen for figures 5A and 5B, i.e. there is a first rod that abuts against the first side 2a’ and a second rod that abuts against the second extendable side 2a”, the movement of said second side then causing the stretching on the material M). It is finally noted that these embodiments (which provides for the variation of the work area) are also applicable in an apparatus that does not include the image detectors 30 (and more generally the digitation of the material) and / or the lighting system 15, and thus the present invention also refers, in a very general way, to an apparatus 1 for the inspection of material M, in particular leather, comprising:

[0153] - a work plane 2 adapted to provide a support plane for the material M, said work plane 2 defining a work area;

[0154] - a control unit C adapted to manage the apparatus 1; and

[0155] - stretching means 10 configured to exert a stretching on the material M arranged on the work plane 2, so as to be able to also identify defects on the material M under stretching, wherein the work plane 2 is extendable by moving at least one side (for instance the side 2a”) thereof, so as to cause the variation of the work area, and wherein the extension of the work plane 2 also causes the stretching on the material M.

[0156] The work plane 2 may comprise a conveyor belt with a movable roll, or it can be a fixed plane but with a movable side, as described above.

[0157] All of the other aspects herein described may be combined with this basic solution which simply precedes the adjustable work area. For instance, to this general solution it is possible to add the digitization through image acquisition, and / or the presence of the lighting system 15, and / or aspects of the stretching means 10, and the like.

[0158] In conclusion, therefore the present invention allows brilliantly overcoming the technical problem, by providing the above apparatus and thus solving all of the prior art drawbacks.

[0159] Advantageously, it is possible to carry out an improved inspection by digitation of a leather under stretching. The particular structure of the stretching means and the configuration of the control unit further ensure the several above indicated advantages.

[0160] Finally, it should be noted that what is illustrated above in relation to the lighting system 15 is independent of the possibility of carrying out a digitation of the material M on the work plane 2, or in relation to the possibility of varying the work area. In this case, it is thus possible to make an apparatus provided with the lighting system 15 and the stretching means 10 (without necessarily making a digital copy of the leather) and, thanks to the lighting system 15 combined with the stretching means 10, the operator is able to identify all defects precisely and quickly.

[0161] As a result, the present invention also relates to an apparatus (still indicated with reference 1) for the inspection of material M, in particular leather, comprising:

[0162] - a work plane 2 adapted to provide a support plane for the material, said work plane 2 having at least one first pair of opposite sides 2a’ and 2a” and at least one second pair of opposite sides 2b’ and 2b”;

[0163] - a control unit C adapted to manage the apparatus 1;

[0164] - stretching means 10 configured to exert a stretching on the material M arranged on the work plane 2; and

[0165] - a lighting system 15 adapted to lighten the material M on the work plane 2, said lighting system 15 comprising:

[0166] - a first set of light sources 15’ arranged and configured to lighten the work plane 2 from an elevated position with respect to said work plane 2, according to a first incidence angle with said work plane 2; and

[0167] - a second set of light sources 15” arranged and configured to emit grazing light to the work plane 2, according to a second incidence angle with said work plane 2 that is smaller than the first incidence angle.

[0168] There are also other optional aspects, possibly combinable to each other, as below illustrated (said aspects corresponding to what has already been illustrated above and are reported just for completeness of description).

[0169] According to an aspect, the apparatus may comprise at least one image detector 30 adapted to capture images of the material M on the work plane 2, wherein the control unit C is configured to process the images captured by said at least one image detector 30 and to generate a digital copy of the inspected material.

[0170] According to an aspect, the second set of light sources 15” may comprise a first plurality di light sources 15”a arranged at at least one of the two opposite sides 2a” of the first pair of opposite sides, and a second plurality of light sources 15”b arranged at at last one of the two opposite sides 2b of the second pair of opposite sides.

[0171] According to an aspect, the control unit C may be configured to allow a relative adjustment between said first plurality of light sources 15”a and said second plurality of light sources 15”b.

[0172] According to an aspect, the control unit C may comprise a memory unit MEM including a plurality of operating instructions, each operating instruction corresponding to a lighting mode of said lighting system 15, wherein said apparatus 1 further comprises means configured to allow the selection of a lighting mode between said stored lighting modes, said control unit C being configured to control the lighting system 15 based on said selection.

[0173] According to an aspect, the memory unit MEM may comprise a plurality of operating instructions stored for a respective plurality of materials, each instruction corresponding to a specific lighting mode of the lighting system 15 adapted to the relative material and selectable through the control unit C. According to an aspect, in a first lighting mode, the control unit C may be configured to set a first intensity and / or colour temperature of the lighting system 15, and, in at least one second lighting mode, the control unit C may be configured to set a second intensity and / or colour temperature of the lighting system 15 different from the first intensity and / or colour temperature.

[0174] According to an aspect, the control unit C may be configured to allow the selective activation of one of the first set of light sources 15’ and the second set of light sources 15”.

[0175] According to an aspect, the control unit C may be configured to adjust the relative intensity between said first set of light sources 15’ and said second set of light sources 15”.

[0176] According to an aspect, the second set of light sources 15” may comprise, at the relative side / s of the work plane 2, a plurality of light sources configured to generate a light beam having an incidence angle with the work plane 2 comprised between 0 and 30°.

[0177] According to an aspect, the second set of light sources 15” may comprise a plurality of light sources arranged on at least two substantially parallel rows.

[0178] According to an aspect, the light sources arranged on a row may be configured to generate a light beam having an incidence angle with the work plane 2 different from that of the light sources arranged on another row.

[0179] According to an aspect, the sides of the first pair of opposite sides 2a’ and 2a” may be sides of greater extension, and the sides of the second pair of opposite sides 2b’ and 2b” may be sides of smaller extension, wherein the first plurality di light sources 15”a is arranged at at least one of the two opposite sides 2a” of greater extension, and wherein the second plurality of light sources 15”b is arranged at at least one of the two opposite sides 2b’, 2b” of smaller extension. According to an aspect, the work plane 2 may be rectangular-shaped.

[0180] According to an aspect, the control unit may be configured to allow the switching of the lighting system at least between a first operating mode, adapted to allow the inspection of the material by the operator, and a second operating mode, adapted to allow capturing images and / or videos by said at least one image detector and which corresponds to a different setting of the lighting system, wherein the optimal operating parameters of said image detector are optimized in relation to the setting of the lighting system in said second operating mode, and wherein, in the passage between the first operating mode and the second operating mode, said parameters of the image detector are not modified.

[0181] According to an aspect, the apparatus may further comprise at least one projector to project elements on the work plane.

[0182] According to an aspect, the control unit C may be configured to define a plurality of work areas Wa based on which the material M placed on the work plane 2 is virtually divided, wherein the projector is configured to project profiles Wap corresponding to said work areas Wa on the work plane 2, each of said profiles Wap being adapted to identify a single work area with respect to the other work areas.

[0183] According to an aspect, the projector may be configured to project the profiles Wap corresponding to the single work areas Wa separately from each other, wherein the control unit C is adapted to allow the selection of a specific profile and thus the passage of the projection of a profile to the projection of a different profile, and wherein said control unit C is further adapted to control the lighting system 15 based on the specific projected profile Wap.

[0184] According to an aspect, the control unit C may be further configured to control the lighting system 15, so as to maintain the light sources of the lighting system 15 corresponding to the non-projected work areas off or with reduced intensity. According to an aspect:

[0185] - the projected profiles Wap may be square or rectangular-shaped,

[0186] - the work plane 2 may be provided with moving means adapted to allow the movement of the material along a feeding direction Dir,

[0187] - the apparatus 1 may comprise means to allow the operation of the moving means based on an input by the user, and

[0188] - the control unit C may be configured to define the size of a side of said square or rectangular shape of the projected profile Wap which extends along a direction D opposite the feeding direction Dir based on the extension of the material M along said direction D, and to adjust the size of a side of said square or rectangular shape of the projected profile Wap which extends along the feeding direction Dir depending on the advancement of the material M along said feeding direction Dir.

[0189] According to an aspect, the apparatus may comprise a signaling element 40 adapted to indicate defects on the surface of the material, wherein the control unit C is further configured to correlate the defects on the material indicated by said signaling element 40 with the captured image of the material, with possible generation of a report indicating at least the shape and position of the defects on said material.

[0190] According to an aspect, the control unit 30 may be configured to automatically detect the defects on the material based on the content of the images captured by the image detector 30.

[0191] According to an aspect, the projector may comprise at least one laser projector, said laser projector being adapted to project, in addition to the profile, even defects of the material identified by the operator inside the corresponding work area through the signaling element.

[0192] According to an aspect, the stretching means 10 may comprise:

[0193] - a first rod 10a associated with a first side 2a’ of the work plane 2, wherein said first rod 10a is configured to move away from and toward said first side 2a’ of the work plane 2 and is configured to abut onto said first side 2 a’, so as to hold a first portion M’ of the material M to be inspected between said first rod 10a and said first side 2a’; and

[0194] - a second rod 10b and a third rod 10c coupled to each other and associated with a second side 2a”, opposite the first side 2a’, of the work plane 2, wherein said second rod 10b and said third rod 10c are movable with respect to each other, so as to house a second portion M” of the material M to be inspected therebetween and to hold said second portion M” therebetween, and wherein said second rod 10b and said third rod 10c are configured to move together in close abutment away from and toward said second side 2 a”.

[0195] According to an aspect, when the first portion M’ of the material M to be inspected is held between the first rod 10a and the first side 2a’ of the work plane 2, and when the second portion M” of the material M to be inspected is held between the second rod 10b and the third rod 10c, the movement of the second rod 10b and third rod 10c away from the second side 2a” of the work plane 2 is such as to cause the stretching on said material M.

[0196] According to an aspect, the control unit C may be configured to automatically carry out an adjustment of the position of the defects which are detected and present in the captured images when the stretching means exert the stretching on the material M, the entity of said adjustment varying based on the position of the defect with respect to the work plane 2 taken as reference.

[0197] According to an aspect, the control unit C may be configured to calculate a deformation undergone by the material M due to the stretching exerted by the stretching means and to establish, based on the calculated deformation, the actual position of the defects identified and present in the captured images when the material M is under stretching. According to an aspect, the control unit C may be configured to recognise and define, based on one or more references on the material M visible in the captured images through the image detector 30, a displacement of said material on the work plane 2 carried out by the operator, and to create said digital copy of the material M taking into account said displacement by joining a plurality of captured images.

[0198] According to an aspect, the work plane 2 may be made of an at least partially transparent material, wherein the apparatus 1 comprises at least one further image detector configured to capture images of the surface of the material M facing toward the work plane 2, the further image detector being opposite the at least one image detector 30 with reference to the work plane 2.

[0199] According to an aspect, the work plane may comprise a conveyor belt configured to move the material arranged thereon.

[0200] According to an aspect, the conveyor belt may comprise at least one first roll at a first side of the work plane, and a second roll at a second side of the work plane, wherein the second roll is movable, so as to cause the movement of the second side of the work plane.

[0201] According to an aspect, the apparatus may comprise a first rod associated with the first side of the work plane, wherein the first rod is configured to move away from and toward said first side of the work plane and is configured to abut against said first side, so as to hold a first portion of the material to be inspected between said first rod and said first side and a second rod configured to move away from and toward the second side of the work plane, so as to hold a second portion of the material to be inspected.

[0202] According to an aspect, the second rod and the second roll are configured to move integrally during the movement of the second side of the work plane.

[0203] Furthermore, as above indicated, in another general case, the present invention also relates, in a very general way, to an apparatus 1 for the inspection of material M, in particular leather, comprising:

[0204] - a work plane 2 adapted to provide a support plane for the material (for instance, the work plane 2 may have at least one first pair of opposite sides 2a’ and 2a”, and at least one second pair of opposite sides 2b’ and 2b”); and

[0205] - stretching means 10 configured to exert a stretching on the material M arranged on the work plane 2, wherein the stretching means comprise:

[0206] - a first rod 10a associated with a first side 2a’ of the work plane 2, wherein said first rod 10a is configured to move away from and toward said first side 2a’ of the work plane 2 and is configured to abut against said first side 2a’, so as to hold a first portion M’ of the material M to be inspected between said first rod 10a and said first side 2a’; and

[0207] - a second rod 10b and a third rod 10c coupled to each other and associated with a second side 2a”, opposite the first side 2a’, of the work plane 2, wherein said second rod 10b and said third rod 10c are movable with respect to each other, so as to house a second portion M” of the material M to be inspected therebetween and to hold said second portion M” therebetween, and wherein said second rod 10b and said third rod 10c are configured to move together in close abutment away from and toward said second side 2 a”.

[0208] According to an aspect, when the first portion M’ of the material M to be inspected is held between the first rod 10a and the first side 2a’ of the work plane 2, and when the second portion M” of the material M to be inspected is held between the second rod 10b and the third rod 10c, the movement of the second rod 10b and third rod 10c away from the second side 2a” of the work plane 2 is such as to cause the stretching on said material M. It is possible to also apply all of the other aspects discussed in the present description. Furthermore, as above indicated, in another general case, the present invention also relates, in a very general way, to an apparatus 1 for the inspection of material M, in particular leather, comprising:

[0209] - a work plane 2 adapted to provide a support plane for the material M, said work plane 2 defining a work area;

[0210] - a control unit C adapted to manage the apparatus 1; and

[0211] - stretching means 10 configured to exert a stretching on the material M arranged on the work plane 2, so as to identify defects even on the material M under stretching, wherein the work plane 2 is extendable by moving at least one side thereof (for instance the side 2a”), so as to cause the variation of the work area. Thus, in this case the work plane 2 comprises a fixed body and a movable portion (which corresponds to the side 2a”). The movable portion is thus identified with the side 2a”.

[0212] According to an aspect, the mechanism itself for the extension of the work plane 2 may be used to also cause the stretching on the material M (for instance through a same motorized means), even if different solutions may also be provided (for instance the table may also be moved manually or in continuous with a worm or snap screw with a series of holes, or in any other suitable way, and then the stretching is applied as in figures 2A and 2B or 5A and 5B).

[0213] According to an aspect, the work plane may comprise a conveyor belt configured to move the material arranged thereon.

[0214] According to an aspect, the conveyor belt may comprise at least one first roll at a first side of the work plane, and a second roll at a second side of the work plane, wherein the second roll is movable, so as to cause the movement of the second side of the work plane.

[0215] According to an aspect, the apparatus may comprise a first rod associated with the first side of the work plane, wherein the first rod is configured to move away from and toward said first side of the work plane and is configured to abut against said first side, so as to hold a first portion of the material to be inspected between said first rod and said first side and a second rod configured to move away from and toward the second side of the work plane, so as to hold a second portion of the material to be inspected.

[0216] According to an aspect, the second rod and the second roll may be configured to move integrally during the movement of the second side del work plane.

[0217] According to an aspect, the work plane is fixed and extendable, in particular the side 2a” thereof is extendable (movable). In particular, according to an aspect, the apparatus may comprise a first rod associated with the first side of the work plane, wherein the first rod is configured to move away from and toward said first side of the work plane and is configured to abut against said first side, so as to hold a first portion of the material to be inspected between said first rod and said first side, and a second rod (or in general portion movable with respect to a fixed body of the plane) which defines the second side of the work plane and configured to move away from and toward the first side of the work plane, so as to increase the work area. A third rod configured to move independently of the second rod (but they can still be arranged on the same guide) and which is configured to abut onto the second rod for holding the material, may also be present. The movement of the second and third rods then causes the stretching on the material M.

[0218] According to an aspect, there may be means configured to close the slot that is formed between the rod 10b and the fixed body of the work plane 2 (such as for instance an appropriate curtain) .

[0219] Alternatively, a telescopic worktable 2 may be provided with an extendable portion, without the need to use the second rod 10b (in this second case the operation is similar to what was seen for figures 5A and 5B, i.e. there is a first rod which abuts against the first side 2a’ and a second rod which abuts against the second side 2a”, the movement of this second side then causing the stretching on the material M).

[0220] According to an aspect, an image detector 30 may be present, which is adapted to capture images of the material M on the work plane 2, wherein the control unit C is configured to process the images captured by the image detector 30 and to generate a digital copy of the inspected material M.

[0221] According to an aspect, the apparatus may further comprise a signaling element adapted to indicate defects on the surface of the material to be inspected, wherein said signaling element is provided with a lighting element able to be detected by the image detector, the coordinates of the movement of said lighting element being calculated through said control unit, and wherein said control unit is configured to recognise the position, and / or shape, and / or entity of the surface of the material based on said coordinates of the movement of the lighting element.

[0222] According to an aspect, the control unit may be configured to automatically carry out an adjustment of the position of the defects which are detected and present in the captured images when the stretching means exert the stretching on the material, the entity of said adjustment varying based on the position of the defect with respect to the work plane taken as reference.

[0223] According to an aspect, the control unit may be configured to calculate a deformation undergone by the material due to the stretching exerted by the stretching means and to establish, based on the calculated deformation, the actual position of the defects identified and present in the captured images when the material is under stretching.

[0224] According to an aspect, the apparatus may comprise a projector adapted to project information on the material, such as for instance the position and / or profile, relatively to the identified defect, in order to provide a feedback to the operator.

[0225] According to an aspect, the control unit may comprise different operating instructions therein stored, said different operating instructions corresponding to different stretching values applicable by the stretching means.

[0226] According to an aspect, the control unit may be configured to allow the selection of an operating instruction between said operating instructions and to control the stretching means based on the selected operating instruction, by applying a specific desired stretching.

[0227] According to an aspect, the work plane may comprise at least one first pair of opposite sides and at least one second pair of opposite sides, said work plane being preferably rectangular-shaped.

[0228] According to an aspect, the apparatus may comprise a lighting system adapted to lighten the material on the work plane, wherein said lighting system comprises a first set of light sources arranged and configured to lighten the work plane from an elevated position with respect to said work plane, according to a first incidence angle with said work plane, and a second set of light sources arranged and configured to emit grazing light to the work plane, according to a second incidence angle with said work plane that is smaller than the first incidence angle.

[0229] According to an aspect, the second set of light sources may comprise a first plurality of light sources arranged at at least one of the two opposite sides of the first pair of opposite sides, and a second plurality of light sources arranged at at least one of the two opposite sides of the second pair of opposite sides.

[0230] Obviously a person skilled in the art, in order to meet contingent and specific needs, may make several changes and variants to the above described apparatus, all of them falling within the scope of protection of the invention as defined by the appended claims.

Claims

CLAIMS1. An apparatus (1) for the inspection of material (M), in particular leather, comprising:- a work plane (2) adapted to provide a support plane for the material (M);- a control unit (C) adapted to manage the apparatus (1); and- at least one image detector (30) adapted to capture images of the material (M) on the work plane (2), wherein the control unit (C) is configured to process the images captured by the image detector (30) and to generate a digital copy of the inspected material (M), the apparatus (1) further comprising stretching means (10) configured to exert a stretching on the material (M) arranged on the work plane (2), so as to identify defects even on the material (M) under stretching.

2. The apparatus (1) according to claim 1, wherein the stretching means (10) comprise:- a first rod (10a) associated with a first side (2a’) of the work plane (2), wherein said first rod ( 10a) is configured to move away from and toward said first side (2a’) of the work plane (2) and is configured to abut onto said first side (2a’), so as to hold a first portion (M’) of the material (M) to be inspected between said first rod (10a) and said first side (2a’); and- a second rod (10b) and a third rod (10c) coupled to each other and associated with a second side (2a”), opposite the first side (2a’), of the work plane (2), wherein said second rod (10b) and said third rod (10c) are movable with respect to each other, so as to house a second portion (M”) of the material (M) to be inspected therebetween and to hold said second portion (M”) therebetween, and wherein said second rod (10b) and said third rod (10c) are configured to move together in close abutment with each other away from and toward said second side (2a”).

3. The apparatus (1) according to claim 2, wherein, when the first portion (Mj of the material (M) to be inspected is held between the first rod (10a) and the first side (2a’) of the work plane (2), and, when the second portion (M’j of the material (M) to be inspected is held between the second rod (10b) and the third rod ( 10c), the movement of the second rod (10b) and the third rod (10c) away from the second side (2a”) of the work plane (2) causes the stretching of said material (M).

4. The apparatus (1) according to claim 2 or 3, wherein said rods (10a, 10b, 10c) are moved by means of motorized means (10m).

5. The apparatus (1) according to any one of the previous claims, further comprising a signaling element (40) adapted to indicate the defects on the surface of the material (M) to be inspected, wherein said signaling element (40) is provided with a lighting element which is adapted to be detected by the image detector (30), the coordinates of the movement of said lighting element being calculated by said control unit (C), and wherein said control unit (C) is configured to recognize the position, and / or shape, and / or entity of the defect of the surface of the material (M) based on said coordinates of the movement of the lighting element of the signaling element (40).

6. The apparatus (1) according to any one of the previous claims, wherein the control unit (C) is configured to automatically carry out an adjustment of the position of the defects which are detected and are present in the captured images when the stretching means exert the stretching on the material (M), the entity of said adjustment varying according to the position of the defect with respect to the work plane (2), which is taken as reference.

7. The apparatus (1) according to any one of the previous claims, wherein the control unit (C) is configured to calculate a deformation which the material (M) is subjected to due to the stretching exerted by the stretching means and to establish, based on the calculated deformation, the actual position of the defects identified and present in the images captured whenthe material (M) is under stretching.

8. The apparatus (1) according to any one of the previous claims, wherein the control unit (C) is configured to recognize and define, based on one or more references on the material (M) which are visible on the images captured by the image detector (30), a displacement of said material on the work plane (2) made by the operator, and to create said digital copy of the material (M) taking into account said displacement by joining a plurality of captured images.

9. The apparatus (1) according to claim 8, wherein said reference is the peripheral profile of the material (M) as detected by the image detector (30).

10. The apparatus (1) according to any one of the previous claims, wherein the work plane (2) is made of an at least partially transparent material, and wherein said apparatus (1) comprises at least one further image detector configured to capture images of the surface of the material (M) facing the work plane (2), said further image detector being opposite the at least one image detector (30) with reference to said work plane (2).

11. The apparatus (1) according to any one of the previous claims, comprising a projector (20) adapted to project on the material (M) information regarding the identified defect, such as for instance the position and / or profile, in order to provide a feedback to the operator.

12. The apparatus (1) according to any one of the previous claims, comprising aspiration means arranged at least along the peripheral edge of the work plane (2), said suction means being adapted to hold the material to be inspected.

13. The apparatus (1) according to any one of the previous claims, wherein the control unit (C) comprises different operating instructions stored therein, said different operating instructions corresponding to different stretching values applicable by the stretching means (10), and wherein said control unit (C) is configured to allow the selection of anoperating instruction among said operating instructions and to control said stretching means (10) based on said selected operating instruction, in such a way to apply a specific desired stretching.

14. The apparatus (1) according to claims 2 and 13, wherein the different operating instructions correspond to different distance values for the movement of the second rod (10b) and of the third rod (10c) away from the work plane (2).

15. The apparatus (1) according to any one of the previous claims, wherein the control unit (C) is configured to automatically detect the defects on the material based on the content of the images captured by the image detector (30).

16. The apparatus (1) according to claim 1, wherein the work plane (2) comprises at least one first pair of opposite sides (2a’, 2a”) and at least one second pair of opposite sides (2b’, 2b”), said work plane (2) being rectangular- shaped.

17. The apparatus (1) according to claim 16, comprising a lighting system (15) adapted to lighten the material (M) on the work plane (2), wherein said lighting system (15) comprises:- a first set of light sources (15’) which are arranged and configured to lighten the work plane (2) from an elevated position with respect to said work plane (2), according to a first incidence angle with said work plane (2); and- a second set of light sources (15”) which are arranged and configured to emit grazing light to the work plane (2), according to a second incidence angle with said work plane (2), said second incidence angle being smaller than the first incidence angle, wherein the second set of light sources (15”) comprises a first plurality of light sources (15”a) arranged at at least one of the two opposite sides (2a”) of the first pair of opposite sides, and a second plurality of light sources( 15”b) arranged at at least one of the two opposite sides (2b) of the second pair of opposite sides.

18. The apparatus (1) according to claim 17, wherein the control unit (C) comprises a memory unit (MEM) including a plurality of operating instructions, each operating instruction corresponding to a lighting mode of said lighting system (15), and wherein said apparatus (1) further comprises means which are configured to allow the selection of a lighting mode among said stored lighting modes, said control unit (C) being configured to control the lighting system (15) based on said selection, and wherein the control unit (C) is configured to allow the selective activation of one of the first set of light sources (15’) and the second set of light sources (15”), and / or configured to adjust the relative intensity between said first set of light sources (15j and said second set of light sources (15”).

19. The apparatus (1) according to any one of the preceding claims, wherein, via said applied stretching, the stretching means (10) are configured to perform a lengthening of the material (M) under inspection.

20. The apparatus (1) according to any one of the preceding claims, wherein the work plane (2) comprises a fixed portion and at least one moving side, and wherein the stretching means (10) are configured to exert said stretching by moving said at least one moving side of the work plane (2) away from the fixed portion.

21. The apparatus (1) according to claim 1, wherein the work plane (2) defines, through an area thereof, a work-area, and wherein said work plane (2) is extendable by moving at least one side (2a”) thereof, so as to cause a variation of said work-area.

22. The apparatus (1) according to claim 1, wherein the work plane (2) comprises a conveyor belt (50) configured to move the material (M) arranged thereon.

23. The apparatus (1) according to claim 22, wherein the conveyor belt(50) comprises at least:- a first roll (50r’) at a first side (2a’) of the work plane (2); and- a second roll (50r”) at a second side (2a”) of the work plane (2), wherein said second roll (50r”) is movable, so as to cause the movement of the second side (2a”) of the work plane (2), and wherein said apparatus (1) comprises:- a first rod (10a’) associated with the first side (2a’) of the work plane (2), wherein said first rod (10a’) is configured to move away from and toward said first side (2a’) of the work plane (2) and is configured to abut against said first side (2a’), so as to hold a first portion (M’) of the material (M) to be inspected between said first rod (10a’) and said first side (2a’); and- a second rod (10b’) configured to move away from and toward said second side (2a”) of the work plane (2), so as to hold a second portion (M”) of the material (M) to be inspected, and wherein said second rod (10b’) and said second roll (50r”) are configured to move integrally during said movement of the second side (2a”) of the work plane (2).

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