Method for detecting the angular position of a hollow body by recording of at least one image of the hollow body

Abstract

The invention relates to a method for detecting the angular orientation of a hollow body (3) comprising a neck (5) having a main vertical axis A, the neck being provided with at least one marking (24) allowing the angular orientation thereof to be determined, the neck (5) comprising at least a hoop (7) and an annular groove (25) extending above the hoop (7), the method comprises at least the following steps: recording at least one image of the neck (5) of the hollow body (3) relative to the hollow body (3) from a defined recording position and along a defined recording axis by means of an image capturing device (26); and processing the at least one image to detect an angular position of the marker (24) relative to a shooting axis of the image capture device (26); the method is characterized in that the step of taking at least one image consists in taking at least one image of the outer periphery of the neck (5) from an image capture device (26) which is positioned on the side of the hollow body (3) at the height of the neck (5) of the hollow body (3) such that the taking axis of the image capture device (26) extends substantially perpendicular to the main axis of the hollow body (3); each hollow body (3) comprises at least two different indicia (24) located in a groove (25) extending above the hoop (7) of the neck (5) of the hollow body (3), the indicia (24) being located in the groove (25) such that at least one of said indicia (24) is in the field of view of the image capture device (26) regardless of the angular orientation of the hollow body (3). The invention also relates to a device for implementing the method.

Description

Technical Field

[0001] The present invention relates to a method for detecting the angular orientation of a hollow body made of thermoplastic material, in particular a preform and / or a container, comprising a neck with a defined main axis, the neck being provided with at least two markings allowing its angular orientation to be determined, and to a device for implementing the method according to the invention. Background Art

[0002] It is known to manufacture containers made of thermoplastic material by blow-molding a preform whose body has been previously heated. The preform has a neck which has been moulded into its final shape, which is therefore intended to remain unchanged during the production of the container.

[0003] Large-scale production of such containers is carried out using blow molding stations equipped with numerous blow molds. This large number of molds allows for the production of containers at a high rate, typically greater than or equal to 50,000 bottles per hour. The molds are carried, for example, by a turntable that rotates to blow mold preforms one after another at a high rate while they move between an introduction point, corresponding to the introduction of the preform into the associated mold, and an ejection point, corresponding to the ejection of the formed container from the mold.

[0004] The container obtained in this way is received by the gripping device of the transfer wheel when leaving the mold, so that it is transported to another device in turn by, for example, a conveyor. The next station is, for example, a container filling station or a container labeling or marking station.

[0005] Furthermore, it is sometimes necessary to change the angular orientation of the preform or container during its movement. Such a change of angular orientation is necessary, for example, when the container has at least one section which is not axisymmetric relative to the neck axis.

[0006] To obtain such non-axisymmetric containers, the preform is usually heated preferentially in certain portions according to a process generally known as "preferential heating." The preform is then received into the mold in a well-defined orientation so that the heated profile of the body corresponds to the cavity of the non-axisymmetric container to be obtained.

[0007] Furthermore, the non-axisymmetric container thus obtained must be presented to a downstream labelling device in a clearly defined orientation in order to apply the label to a receiving surface provided for this purpose on the non-axisymmetric container.

[0008] Such changes may also be required in other configurations, such as on certain axisymmetric or non-axisymmetric containers intended to be equipped with a spray gun, where the spray gun must be properly oriented relative to the container label.

[0009] These stations are usually equipped with container transport devices such as turntables. The change of the angular orientation of the container can also take place directly on the transport device, rather than just on the transfer device between the two stations.

[0010] To allow for the correct orientation of preforms and / or containers, it is known to provide the necks of the preforms with markings that allow for their angular orientation relative to the support about the neck axis. Since the neck retains its shape during the container manufacturing process, the markings can still be used to allow for the orientation of the finished container about its neck axis. Such markings are formed, for example, by notches made in the neck hoop or by lugs made in a groove located in the base of the hoop.

[0011] This marking allows determining the angular orientation of the preform or container relative to its support and, if necessary, changing the angular orientation of the preform or support to bring the marking into a determined reference position relative to the support.

[0012] In the following of this description, the term "hollow body" will be used to refer indiscriminately to preforms or finished containers.

[0013] In order to determine the angular position of the mark relative to the support of the hollow body, it has been proposed to use an image capture device whose imaging axis coincides with the axis of the preform neck. This image capture device thus allows a single image of the hoop to be captured in order to detect the mark formed by the notch made in the hoop's periphery.

[0014] However, this device does not allow to see on the image marks that may be hidden by other elements of the preform. Thus, the image does not allow to see the marks formed by the lugs located in the grooves made in the neck face parallel to its axis.

[0015] Furthermore, some containers require the use of preforms without a collar. In such cases, the preform is fitted with a cap bearing a removable collar to allow handling of the preform during the manufacturing process of the finished container. However, such a collar is movable relative to the hollow body and therefore cannot be used to carry a marking. The marking is therefore necessarily carried by the neck face, which is parallel to its axis. Such a marking is difficult to detect with prior art devices and may even be completely hidden by the collar, which may be between the image capture device's field of view and the marking.

[0016] Furthermore, documents EP 2 439 488, EP 2 439 490 and FR 3 088 112 are known, which describe methods and devices for detecting the angular position of hollow bodies, in particular preforms.

[0017] Document EP2439488 describes a method and device for optically recording the angular position of a thread of a moving container (e.g., a preform). The method comprises: a step of defining an orientation of the longitudinal axis of the container relative to an optical detection device located below the container by means of a positioning device, the positioning device being connected to a defined coupling region of the container; and a step of contactlessly recording a position value and information relating to at least the associated angular position of at least one threaded portion relative to at least one reference point, the reference point being oriented in a defined manner and positioned independently of the angular position of the container; recording at least two position values of the formed threaded portion that are clearly spaced apart from one another, and identifying their deviations relative to one another and / or relative to a reference point, the reference point being the defined oriented container portion and / or at least one defined mark formed by the detection device in the trajectory of the positioning device. The data is then transmitted to a processing device, which, taking into account the defined reference quantity and the two position values, generates data on the angular position of the container.

[0018] The disadvantage of this type of device and method is that it is only applicable to containers whose necks include a threaded portion that can receive a stopper. However, more and more containers do not have a threaded portion on the neck.

[0019] Document EP2439490 describes an apparatus and method for identifying the rotational position of a plastic preform. The apparatus comprises an image capture system that captures spatially resolved images of a plastic container. The image capture system is arranged so that it views the plastic container approximately along its longitudinal direction. The apparatus also comprises an illumination system and an evaluation system. The illumination system illuminates at least one region of the plastic container viewed by the image capture system. The evaluation system determines the angular position of the container relative to its longitudinal extent based on the at least one image captured by the image capture system. The illumination system illuminates the container from at least two different directions so as to illuminate the entire support ring of the container.

[0020] However, the location of the image capture system and the lighting system makes this type of device particularly large and cumbersome.

[0021] Document FR3088112 describes a method and a device for detecting the angular orientation of a hollow body made of thermoplastic material, in particular a preform, comprising a neck having a defined main axis and provided with a marking capable of determining its angular orientation. The method comprises: a first step of capturing at least one image of the neck of the hollow body by means of at least one image capture device from a defined imaging position and along a defined imaging axis relative to the hollow body; and a second step of processing the at least one image to detect the angular position of the marking relative to the imaging axis of the at least one image capture device. The step of capturing at least one image consists in capturing at least two images of the outer periphery of the neck from imaging positions eccentric to the main axis of the neck, these imaging positions being distributed around the main axis of the neck so that all images show the entire outer periphery of the neck.

[0022] This type of device also has the disadvantage of being bulky, heavy and expensive, considering the number of image capture devices required to implement the method.

[0023] Therefore, there is a need to determine the angular position of a preform, in particular in a manner that is compact and inexpensive. Summary of the Invention

[0024] One of the objects of the present invention is therefore to overcome these drawbacks by proposing a method and a device for detecting the angular orientation of a hollow body which are simple and inexpensive in design, have small physical dimensions, and use only a single image capture device.

[0025] To this end, according to the invention, a method is proposed for detecting the angular orientation of a hollow body made of thermoplastic material, in particular a preform and / or a container, comprising a neck having a defined vertical main axis A, the neck being provided with at least one marking allowing its angular orientation to be determined, the neck comprising at least a hoop and an annular recess extending above the hoop, said method comprising at least the following steps:

[0026] - recording at least one image of the neck of the hollow body by means of an image capture device from a recording position determined relative to the hollow body and along a recording axis determined relative to the hollow body;

[0027] - processing the at least one image to detect the angular position of the marking relative to the shooting axis of the image capture device;

[0028] The method is characterized in that the step of taking at least one image consists in taking at least one image of the outer periphery of the neck from an image capture device, the image capture device being positioned on the side of the hollow body at the height of the neck of the hollow body so that the shooting axis of the image capture device extends approximately perpendicular to the main axis of the hollow body; and each hollow body includes at least two different marks, the at least two marks being positioned in grooves extending above the hoop of the neck of the hollow body, the marks being positioned in the grooves so that at least one of the marks is in the field of view of the image capture device regardless of the angular orientation of the hollow body.

[0029] Preferably, the image recording of the outer periphery of the hollow body is performed such that the two side edges of the groove extend above the collar of the neck of the hollow body.

[0030] In addition, the method includes an image processing step of processing the image captured by the image capture device, wherein the image processing step includes at least a step of detecting the position of each side edge of the groove, a step of detecting the position of at least one mark between the side edges of the groove, and a step of determining the angular position of the hollow body based on the position of the mark relative to the two side edges of the groove.

[0031] According to a first embodiment variant, the hollow body is transported along a defined path relative to a fixed frame, the image capture device is fixed relative to the frame, and images are taken when the hollow body passes at least one defined point of the path.

[0032] According to a second embodiment variant, the hollow body is transported along a defined path relative to a fixed frame, and the image capture device moves together with the hollow body during its transport.

[0033] Preferably, the markings located in the groove extending above the hoop of the neck of the hollow body are formed by alphanumeric characters and / or symbols and / or geometric figures and / or pictograms and / or Unicode characters.

[0034] The symbols are mathematical symbols and / or currency symbols and / or typographical symbols.

[0035] Furthermore, the marking is applied by laser engraving or mechanical engraving or hot embossing or moulding to the bottom of a groove extending above the hoop of the neck of the hollow body.

[0036] Another object of the present invention relates to a device for implementing the method, which device comprises at least: a support intended to receive the hollow body and mounted to move along a determined path; and an image capture device arranged on the side of the hollow body at the height of the neck of the hollow body, so that the shooting axis of the image capture device extends approximately perpendicular to the main axis of the hollow body and is coplanar with the annular groove extending above the hoop of the neck of the hollow body.

[0037] Advantageously, the device comprises at least one light source capable of illuminating the entire periphery of the neck and / or all or part of the groove extending above the hoop of the neck of the hollow body.

[0038] According to a first variant embodiment, the light source is an annular light source coaxial with the main axis A of the neck of the hollow body.

[0039] According to a second embodiment variant, the light source is a point light source positioned above the image capture device and oriented towards a groove extending above the collar of the neck of the hollow body.

[0040] Furthermore, in another embodiment, the image capture device is movable together with the support of the hollow body.

[0041] Alternatively, the image capture device is integral with a fixed frame, and the support of the hollow body is movable relative to the frame.

[0042] Furthermore, the device comprises an image processing device for processing images taken by the image capture device, the image processing device comprising at least an algorithm for detecting the position of each side edge of a groove extending above the hoop of the neck of the hollow body, an algorithm for detecting the position of at least one mark between the side edges of the groove, and an algorithm for determining the angular position of the hollow body based on the position of the mark relative to the two side edges of the groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Further advantages and features will emerge more clearly from the following description of several embodiments of the device and method for detecting the angular orientation of a hollow body made of thermoplastic material according to the invention, given by way of non-limiting example, with reference to the accompanying drawings, in which:

[0044] Figure 1 is a schematic top view of a container manufacturing apparatus implemented according to the teachings of the present invention,

[0045] Figure 2 is a side view of a hollow body provided with markings for its angular position,

[0046] Figure 3 yes Figure 2 Detail on a larger scale from the side of the neck of the hollow body provided with markings allowing its angular position to be detected,

[0047] Figure 4 is a side view of a camera assembly for implementing the method for detecting the angular orientation of a hollow body according to the present invention, the camera assembly comprising a single image capture device,

[0048] Figure 5 is a side view of an embodiment variant of a camera assembly for implementing the method according to the invention for detecting the angular orientation of a hollow body,

[0049] Figure 6 is a photograph of an image captured by the device for detecting the angular orientation of a hollow body according to the invention. DETAILED DESCRIPTION

[0050] In the following description of the device and method according to the invention for detecting the angular orientation of a hollow body made of thermoplastic material, like reference numerals denote like elements. The different figures are not necessarily drawn to scale.

[0051] Furthermore, in the following of this description, for the sake of clarity, the terms “higher”, “lower” and the derivative terms “upper”, “lower” are used with reference to the directions of the drawings, without having any limiting scope.

[0052] Figure 1 Schematically shown in FIG 1 is a production device 1 for producing containers 2 from preforms 3 made of thermoplastic material, more particularly from PET (polyethylene terephthalate) or rPET (recycled polyethylene terephthalate).

[0053] Figure 2 , a hollow body is shown, in this case a preform 3, which is usually obtained by injection molding. Typically, such a preform 3 comprises a main body 4 of cylindrical shape with an axis "A". The upper end of the main body 4 is open by a neck 5, which has the final shape of the neck of the container 2 to be obtained (it is usually not subjected to any deformation during the manufacture of the container). The main body 4 comprises a bottom 6 which closes its lower end and is usually hemispherical in shape. The neck 5 comprises a hoop 7 arranged at its junction with the main body 4. The lower surface of the hoop 7 is intended to form a bearing surface 8 to allow the preform 3 to be supported during the molding of the preform, as will be described below.

[0054] At the end of its injection molding, the preform 3 is suddenly cooled to give the thermoplastic material an amorphous state. Therefore, the thermoplastic material can be made ductile again by heating it above the glass transition temperature.

[0055] The bottom 6 of the preform 3 has, at its intersection with the axis “A” of the body 4 , an injection point 9 corresponding to the injection point of the thermoplastic material during its injection molding.

[0056] Refer again Figure 1 The manufacturing apparatus 1 comprises a heating station 10 and a forming station 11. The preforms 3 are moved in a row along a production path 12 passing through the heating station 10 and the forming station 11. The moving direction of the preforms 3 is Figure 1 Indicated by the arrow “ F1 ” in FIG. 1 , during normal operation of the manufacturing apparatus 1 , the preforms 3 are constantly moved along the production path 12 .

[0057] The purpose of the heating station 10 is to heat the body 4 of the preform 3 to a temperature higher than or equal to the glass transition temperature of the constituent material, for example higher than 70° C. when the material is PET. The heating station 10 comprises a conveyor 13 (shown schematically) for conveying the preform 3 while rotating the preform itself.

[0058] The conveyor 13 generally comprises a mandrel 14 which engages with the neck 5 to convey the preform 3. The mandrel 14 moves along a closed loop and is carried, for example, by links of a chain or by a separate carriage moving along a track.

[0059] The circuit here comprises two parallel straight sections connected by a 180° bend. The conveyor 13 also comprises two guide wheels 15A, 15B for guiding the spindle 14 in the bend of the closed circuit.

[0060] The heating station 10 also comprises a heating device 16 for heating the preforms 3. This involves, for example, a lamp facing a reflector or a laser source emitting electromagnetic radiation in the infrared range. In a variant of the invention not shown, the heating device emits electromagnetic radiation in the microwave range.

[0061] The heating device 16 is arranged along the heating zone 17 of the preform production path 12. Figure 1 In the example shown, the heating station 10 comprises a heating zone 17 divided into two parts arranged upstream and downstream of a bend guided by the guide wheel 15B.

[0062] The preforms 3 enter the heating station 10 and are mounted on a conveyor 13, where they travel along a U-shaped section of their production path 12, passing through a heating zone 17. As they travel, they are heated by heating devices 16, which are optionally placed on one or both sides of the preforms 3 relative to their direction of travel. After passing through the heating zone 17, the hot preforms 3 are removed from the heating station 10 and transferred to the molds of the forming station 11 by a first transfer device 18, such as a transfer wheel, interposed between the heating station 10 and the forming station 11.

[0063] According to a non-limiting embodiment, the preform 3 is heated with the neck 5 facing upwards. It is quite clear that the preform 3 can be heated with the neck 5 facing downwards and turned over to have the neck 5 facing upwards between the time it leaves the heating zone 17 and the time it leaves the conveyor 13, without going beyond the scope of the invention.

[0064] The transfer wheel comprises arms (not shown, as they are known per se) which successively grasp the preforms 3 at their necks 5 as they leave the heating station 10 in order to introduce them one after the other into the molds 19 of the molding station 11. The molding station 11 comprises a rotating turntable 20, around the periphery of which are arranged a plurality of blowing stations 21.

[0065] Each blow-molding station 21 comprises at least one mold 19 , a mold generally consisting of three parts, namely two mold halves 19A, 19B and a mold base 19C, which define a mold cavity 22 with the cavity of the container 2 .

[0066] Each hot preform 3 leaving the heating station 10 is introduced into a mold 19 of the blow molding station 21 in order to be blown therein and transformed into a container 2. Once completed, the container 2 is removed from the blow molding station 21 by a second transfer device 23, which is similar to the first transfer device 18 and is well known to those skilled in the art. The mold cavity 22 of the mold 19 includes an upper axial channel to allow the neck 5 of the preform 3 to extend out of the mold cavity 22. Thus, the body 4 is received in the mold cavity 22, while the neck 5 remains above the mold cavity 22, and the preform 3 is held in place by the contact between the support surface 8 of its hoop 7 and the channel periphery. Therefore, the position of the support surface 8 of the hoop 7 constitutes an unchanging fixed position for any preform 3 introduced into the relevant mold 19.

[0067] As explained in the introduction, in some applications it is necessary to orient the preform and / or final container before processing. For example, a preform heated according to a "preferred" heating profile should be oriented to correspond to the shape of the mold cavity in the forming station.

[0068] For this purpose, refer to Figures 2 to 6 The present invention relates to a method for detecting the angular orientation of a preform 3 (or any other hollow body made of thermoplastic material) and / or a container comprising a neck with a defined vertical main axis A, provided with at least one marking 24 allowing its angular orientation to be determined, the neck 5 comprising at least a collar 7 and an annular groove 25 extending above the collar. This marking 24 makes it possible to determine the angular orientation of the preform 3 or container relative to its support and, if necessary, to change the angular orientation of the preform 3 or the support so as to bring the marking 24 into a defined reference position relative to the support.

[0069] The method comprises at least the following steps:

[0070] i) recording at least one image of the neck 5 of the preform 3 by means of the image capture device 26 from a recording position determined relative to the hollow body 3 and along a recording axis determined relative to the hollow body 3;

[0071] ii) processing the at least one image to detect the angular position of the marking 24 relative to the shooting axis of the image capture device.

[0072] According to an essential feature of the method, the step i) of capturing at least one image consists in capturing at least one image of the outer periphery of the neck 5 from an image capturing device 25 positioned at the height of the neck 5 of the preform 3 on the side of the preform so that the capturing axis of the image capturing device 26 extends substantially perpendicularly to the main axis A of the preform 3, e.g. Figure 4 and Figure 5 shown.

[0073] Special reference Figure 2 and Figure 3 Each preform 3 includes at least two different markings 27, which are positioned in a groove 25 extending above the collar 7 of the neck 5 of the preform 3. The markings 27 are positioned in the groove 25 so that at least one of the markings 27 is within the field of view of the image capture device 26 regardless of the angular orientation of the preform. The markings 27 positioned in the groove 25 extending above the collar 7 of the neck 5 of the preform 3 are formed by alphanumeric characters and / or symbols and / or geometric figures and / or pictograms and / or Unicode characters. The symbols are, for example, mathematical symbols such as the addition + sign and / or currency symbols and / or typographic symbols.

[0074] It can be observed that the marking 27 is applied to the bottom of the groove 25 extending above the collar 7 of the neck 5 of the preform 3 by laser engraving or mechanical engraving or hot stamping or molding or any other process known to those skilled in the art.

[0075] Preferably, the image capture of the outer periphery of the preform 3 is performed so that the two side edges of the groove 25 extend above the hoop 7 of the neck 5 of the preform 3. To this end, the image capture device 26 is positioned aligned with the groove 25 of the preform and at a suitable distance so that the side edges of the groove 25 are in the field of view of the image capture device.

[0076] In addition, the method also includes an image processing step of processing the image captured by the image capture device 26, wherein the image processing step includes at least a step of detecting the position of each side edge of the groove 25 of the preform 3, a step of detecting the position of at least one mark 27 between the side edges of the groove 25, and a step of determining the angular position of the preform 3 based on the position of the mark 27 relative to the two side edges of the groove 25.

[0077] According to Figure 1In the first embodiment variant shown, the preforms 3 are transported along a defined path relative to a fixed frame, the image capture device 26 being fixed relative to the frame and the images being taken when the preforms 3 pass through at least one defined point of the path.

[0078] According to a second embodiment variant not shown in the figures, the preforms 3 are transported along a defined path relative to a fixed frame, and the image capture device 26 moves together with the preforms 3 during their transport.

[0079] Reference Figure 1 and Figure 4 The device for implementing the method according to the invention comprises a support 28 intended to receive a preform 3 (or hollow body), the support 28 being mounted so as to be movable along a defined path of the manufacturing apparatus 1, in this case, along its path 12; and an image capture device 26 arranged on the side of the preform 3 at the level of the neck 5 of the preform, such that the image capture axis of the image capture device 26 extends substantially perpendicularly to the main axis of the preform 3 and is coplanar with the annular groove 25 extending above the collar 7 of the neck 5 of the preform 3. Advantageously, the device comprises at least one light source 29 capable of illuminating the entire periphery of the neck 5 and / or all or part of the groove 25 extending above the collar 7 of the neck 5 of the preform 3. In this particular embodiment, the light source 29 is a point light source positioned above the image capture device 26 and oriented towards the groove 25 extending above the collar 7 of the neck 5 of the preform 3.

[0080] According to a variant embodiment, referring to Figure 5 The light source 29 is an annular light source coaxial with the axis A of the neck 5 of the preform 3 .

[0081] Alternatively, the image capture device 26 may be movable together with the support of the hollow body or may be integrally connected to a fixed frame, and the support of the hollow body may be movable relative to the frame.

[0082] In addition, refer to Figure 6 , the device includes an image processing device for processing the images taken by the image capture device 26, the image processing device including at least an algorithm for detecting the position of each side edge of the groove 25 extending above the hoop 7 of the neck 5 of the hollow body, an algorithm for detecting the position of at least one mark 27 between the side edges of the groove 25, and an algorithm for determining the angular position of the hollow body based on the position of the mark 27 relative to the two side edges of the groove 25.

[0083] Finally, it is quite clear that the examples just given are only specific illustrations and do not in any way limit the field of application of the invention.

Claims

1. A method for detecting the angular orientation of a hollow body (3) made of thermoplastic material, in particular a preform and / or a container, comprising a neck (5) with a defined vertical main axis A, the neck being provided with at least one marking (24) allowing its angular orientation to be determined, the neck (5) comprising at least a hoop (7) and an annular groove (25) extending above the hoop (7), the method comprising at least the following steps: - recording at least one image of the neck (5) of the hollow body (3) by means of an image capture device (26) from a recording position determined relative to the hollow body (3) and along a recording axis determined relative to the hollow body (3); - processing the at least one image to detect the angular position of the marker (24) relative to the shooting axis of the image capture device (26); - the step of capturing at least one image consists in capturing at least one image of the outer periphery of the neck (5) from an image capturing device (26), the image capturing device being positioned at the height of the neck (5) of the hollow body (3) on the side of the hollow body (3) such that the capturing axis of the image capturing device (26) extends substantially perpendicularly to the main axis of the hollow body (3), each hollow body (3) comprising at least two different markings (24), said at least two markings being positioned in a groove (25) extending above the hoop (7) of the neck (5) of the hollow body (3), the markings (24) being positioned in the groove (25) such that at least one of said markings (24) is in the field of view of the image capturing device (26) regardless of the angular orientation of the hollow body (3); Its characteristics are: The method comprises an image processing step of processing an image captured by an image capture device (26), the image processing step comprising at least a step of detecting the position of each side edge of the groove (25), a step of detecting the position of at least one mark (24) between the side edges of the groove (25), and a step of determining the angular position of the hollow body (3) based on the position of the mark (24) relative to the two side edges of the groove (25).

2. The method according to claim 1, characterized in that The image recording of the outer periphery of the hollow body is carried out so that the two side edges of the groove ( 25 ) extend above the collar ( 7 ) of the neck ( 5 ) of the hollow body ( 3 ).

3. The method according to claim 1 or 2, characterized in that The hollow body (3) is transported along a determined path (12) relative to a fixed frame, the image capture device (26) is fixed relative to the frame, and images are taken when the hollow body (3) passes at least one determined point of the path (12).

4. The method according to claim 1 or 2, characterized in that The hollow body (3) is transported along a determined path (12) relative to a fixed frame, and the image capture device (26) moves together with the hollow body (3) during the transport of the hollow body.

5. The method according to any one of claims 1 to 4, characterized in that The marking (24) positioned in the groove (25) extending above the hoop (7) of the neck (5) of the hollow body (3) is formed by alphanumeric characters and / or symbols and / or geometric figures and / or pictograms and / or Unicode characters.

6. The method according to claim 5, characterized in that The symbol is a mathematical symbol and / or a currency symbol and / or a typographical symbol.

7. The method according to any one of claims 1 to 6, characterized in that The marking (24) is applied by laser engraving or mechanical engraving or hot stamping or molding to the bottom of a groove (25) extending above the collar (7) of the neck (5) of the hollow body (3).

8. A device for implementing the method according to any one of the preceding claims, the device comprising at least: A support (28) intended to receive a hollow body (3) mounted to move along a determined path (12); and an image capture device (26) arranged on the side of the hollow body (3) at the height of the neck (5) of the hollow body (3) so that the shooting axis of the image capture device (26) extends approximately perpendicular to the main axis of the hollow body (3) and is coplanar with the annular groove (25) extending above the hoop (7) of the neck (5) of the hollow body (3), characterized in that the device includes an image processing device for processing the image captured by the image capture device (26), the image processing device including at least an algorithm for detecting the position of each side edge of the groove (25) extending above the hoop (7) of the neck (5) of the hollow body (3), an algorithm for detecting the position of at least one mark (24) between the side edges of the groove (25), and an algorithm for determining the angular position of the hollow body (3) based on the position of the mark (24) relative to the two side edges of the groove (25).

9. The device according to claim 8, characterized in that The device comprises at least one light source (29) capable of illuminating the entire periphery of the neck (5) and / or all or part of the groove (25) extending above the hoop (7) of the neck (5) of the hollow body (3).

10. The device according to claim 8, characterized in that The light source (29) is an annular light source coaxial with the main axis A of the neck (5) of the hollow body (3).

11. The device according to claim 8, characterized in that The light source (29) is a point light source positioned above the image capture device (26) and oriented towards a groove (25) extending above the hoop (7) of the neck (5) of the hollow body (3).

12. The device according to any one of claims 8 to 11, characterized in that The image capture device (26) is movable together with the support (28) of the hollow body (3).

13. The device according to any one of claims 8 to 11, characterized in that The image capturing device (26) is integrally connected to the fixed frame, and the support (28) of the hollow body (3) is movable relative to the frame.

Images