Method and device for reading a marking printed or engraved on a reflective convex object

Abstract

The present invention relates to a device and a method for reading markings on a convex reflective object (1), such as a wine bottle. The technical solutions of the invention are particular in that they propose direct reading and from a right angle facing the marking, and the neutralization of any parasitic reflection by means of lighting (3) configured with a concave luminous wall. In particular, the concave luminous wall of the lighting has a curvature substantially following a curvature ((1) of the convex object (1) at its marking (2). The invention also relates to a method and device for reading markings on convex reflective objects moving on a conveyor belt. figure for abstract: figure 2

Description

Title of the invention: Method and device for reading a marking printed or engraved on a reflective convex object TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of reading markings, and relates in particular to a method and device for reading markings affixed to reflective convex objects, such as tracking codes engraved or marked on glass bottles.

[0002] The invention also relates to a method and device for reading markings suitable for reading markings on convex objects moving on a conveyor belt. STATE OF THE ART

[0003] In industrial processes, it is essential to be able to trace objects automatically. For this purpose, the objects to be traced are generally marked with a batch number or a unique number that must be able to be reread at different stages of the process using cameras or optical readers. For productivity reasons, this rereading must be able to be done on conveyors or in production equipment without stopping the product packaging and wrapping processes.

[0004] In an automated marking reading process, it is necessary to scroll the marked products in front of a camera or an optical reader. Several constraints are encountered in this process. First of all, the speed of scrolling of the products imposes a first constraint on the optical reading means which must be more or less efficient depending on this speed. The contrast of the marking also defines its ease or difficulty of reading. When the markings are affixed to a label, the contrast will be greater and will be easier to read. However, reading is more restrictive when the marking is printed or engraved directly on the surface of the object and its contrast is low.

[0005] In order to maximize the chances of reading, whatever the environment and the scrolling speed of the markings, lighting is associated with the camera. Thus, if the marking enters the reading focal zone of the camera under correct lighting conditions and sufficient contrast, the camera is able to read the marking. However, for low contrast markings these conditions are difficult to meet. A particularly restrictive case is that of markings engraved on reflective convex objects, such as a Datamatrix marking engraved on a wine bottle, and for which there is still a strong need for new technical solutions for its reading.

[0006] American patent application US2006 / 00912214 gives an example of a reading method suitable for reading markings on convex objects. A device is proposed comprising a camera located in the center of a light diffusion screen. The light diffusion element aims to create uniform lighting over the reading area and to avoid as much as possible reflections or spots of light likely to disturb the reading of the camera. The hole required by the camera in the center of this diffusion element, at the right angle to the marking to be read, has the effect of creating a shadow zone precisely in the reading area of ​​the camera. In the case of a glass surface, specular reflections are created, which impairs the reading of the code. The originality of the method lies in the implementation of a light diffusion chamber making it possible to generate differences in contrast during the exposure of the code.The reflected light is converted into electrical signals that allow the marking to be decoded. This is therefore an indirect code reading process.

[0007] Patent EP 2 297 672 B1 gives another example of a device allowing the reading of markings on reflective convex objects. This document describes a device also using a camera combined with a lighting source with a backlit diffuser screen. Compared to the previous reference, the camera is inclined at an angle alpha relative to the normal of the marking to be offset from the diffuse light source and thus not create a shadow zone in the reading area of ​​interest. For its part, the flat screen of the light source is offset relative to the camera and is configured to allow the capture of a virtual image created by the reflection of the surface of the marking on the internal surface of the article, and which is superimposed with the marking.This solution makes it possible to avoid creating the dark reading zone in the marking, however it has the disadvantage of shifting the axis of the camera and consequently distorting the image of the marking to be read, which disrupts the correct interpretation of the image. In addition, this solution requires very precise positioning of the marking with respect to the light source to enable the reading of said virtual image, and the slightest imperfection can lead to poor reading. These two patents, although very different, have in common a particular treatment of shadows or reflections in combination with the marking and consequently an indirect reading of said marking.

[0008] Furthermore, another major difficulty in reading markings on conveyed objects is linked to the random positioning of the marking as it passes in front of the camera. To solve this problem, the most sophisticated packaging lines integrate product rotation means allowing the marking to be positioned facing the viewing angle of the reading means, for example by means of a robot arm or a rotating belt. It is also known to use very high-performance optical sensors but which nevertheless have a very high investment price. Statement of the invention

[0009] The present invention aims to remedy all or part of the drawbacks of the state of the art cited above, in particular by direct capture of the marking and not by combined processing of shadows or reflections.

[0010] More particularly, the invention has as its first aim to propose a new method and device for reading markings on a convex object, and in particular on a convex object having a reflective surface.

[0011] A second aim of the invention is that this method and device are suitable for reading a marking on a convex object moving on a conveyor belt.

[0012] The invention thus proposes a method for reading a marking on a convex object, said method comprising the following actions: - illumination of said marking by means of extended lighting defining a concave luminous wall, and having a curvature substantially following a curvature of said convex object at the level of its marking, preferably substantially parallel to a curvature of said convex object at the level of its marking, and

[0013] -reading and / or capturing in photo said marking thus illuminated by means of an optical reader and / or a camera (4) positioned facing said marking, and with a substantially normal observation axis and aiming at said marking so as to be able to read the marking with a minimum of deformation.

[0014] The method of the invention is very advantageous in that it offers direct reading facing the marking, allowing the best interpretation of the latter. This reading is optimized by the use of said lighting defining a concave luminous wall adapting to a curvature of the convex object at the level of its marking. This concave luminous wall makes it possible to neutralize any parasitic reflection in the area of ​​the marking and to optimally contrast the marking for its reading or photographing.

[0015] When the object has a highly reflective surface, for example a glass wine bottle, the invention proposes a specific arrangement of said lighting. In particular, when the convex object has a reflective and / or transparent surface, and said lighting is installed facing the marking in height offset with said camera, and is inclined at an angle to illuminate said marking with incident radiation.

[0016] This arrangement makes it possible to avoid the appearance of a shadow in the reading area of ​​the marking. This arrangement is also very advantageous for contrasting raised or recessed markings on the surface of the object, such as two-dimensional engraved tracking codes, for example an engraved Datamatrix. Indeed, the inclination of the lighting will illuminate the depressions of said marking with incident radiation and create reflections on said marking in the axis of the reader or the camera.

[0017] The concave light wall of the lighting is not a physical part of the lighting but a light emitted by the lighting in the form of a concave wall. The concave light wall can be configured in several ways. In one embodiment, said lighting comprises a plurality of light sources arranged along a curved line defining a curvature of said concave light wall and being installed independently or fixed together on a support.

[0018] In a preferred embodiment, said plurality of light sources is fixed on a support having a concave wall making it possible to arrange and fix said plurality of light sources along said curved line, and said support preferably incorporates a light diffusing screen also matching the shape of said concave wall on a front face of said support backlit by said plurality of light sources.

[0019] In one embodiment, said marking is engraved on a convex object having a circular cylindrical shape, and the concave luminous wall of said lighting has a semi-circle or arc of a circle shape, preferably substantially concentric with the convex object.

[0020] For example, said convex object is a wine bottle, and said marking is an engraved Datamatrix. In particular, the engraved Datamatrix consists of depressions, such as semi-spherical depressions, and the illumination inclined at an angle generates incident radiation which produces a reflection in each depression, and which is detected by said optical reader and / or camera placed in the axis normal to the marking.

[0021] The invention also proposes rotating said convex object on itself and in the axis of the lighting and said optical reader and / or a camera so that at a moment of rotation the incident lighting meets the marking and the reflection on the marking is directed towards the reader or the camera.

[0022] As already mentioned, a second object of the invention is to propose a method suitable for reading markings on conveyed products. In this embodiment, said convex object moves on a conveyor belt, and reading the marking comprises the passage of said convex object through a reading zone of said conveyor belt, said reading zone comprising on one side and on the other:

[0023] -a plurality of cameras arranged and configured to capture a photo of said convex object from several viewing angles as it passes through said reading zone, and

[0024] -at least one of said lightings configured to illuminate the convex object when it is captured in photo by said cameras.

[0025] Said method comprises the analysis of the photos taken by said cameras, and the selection of at least one photo comprising the marking of the convex object allowing its reading.

[0026] Advantageously, this method allows the reading of a marking positioned randomly on a product moving on a conveyor belt, and this with low-cost equipment and without implementing a step of repositioning the product.

[0027] In particular, installed on one side and another of the reading area are configured to partially encircle the reading area with their concave light wall, and are preferably installed in height offset with said plurality of cameras and inclined at an angle to illuminate said marking with incident radiation.

[0028] In an improved embodiment, said reading zone comprises an obstacle comprising an adherent part in a trajectory of the convex object and being configured to weakly resist the passage of said convex object. The obstacle generates an at least partial rotation of said object by friction between its said adherent part and the object moving in contact with said adherent part, and when the object continues its movement and passes said obstacle. The rotation of the object makes it possible to carry out a 360-degree control of the object. A degree of rotation to be imparted to the object will be chosen according to the number of cameras surrounding the object and the parts of the object not visible to said cameras.

[0029] The invention also relates to a device for reading a marking on a convex object of circular cylindrical shape at the level of said marking, said device comprising at least one camera or optical reader and lighting installed at the level of a reading zone of a conveyor belt, characterized in that the lighting defines a concave luminous wall having a curvature substantially following a curvature of said convex object at the level of its marking, and preferably said lighting is inclined at an angle with respect to an observation axis of said at least one camera or optical reader.

[0030] In one embodiment, a plurality of light sources arranged along a curved line defining a curvature of said concave light wall and being installed independently or fixed together on a support. For example, said plurality of light sources is fixed on a support having a concave wall making it possible to arrange said plurality of light sources along said curved line, and preferably incorporates a light diffusing screen also matching the shape of said concave wall. In one embodiment suitable for reading markings on convex moving objects, the device comprises a plurality of cameras and at least two of said lightings, each lighting defining a concave light wall in the shape of a semicircle or an arc of a circle.

[0031] Similarly, the device may comprise a marking reading program executable on a control terminal, a presence detector, a plurality of cameras, and at least two of said lightings and a presence detector, and

[0032] -said plurality of cameras and said at least two lights are configured to activate simultaneously upon detection of an object by said object detector, and

[0033] -said plurality of cameras is configured to transmit photos taken upon detection of an object to said marking reading program, and preferably

[0034] - comprises an obstacle comprising an adherent part installed in an area of reading of a conveyor belt, and being configured to weakly resist the passage of said convex object. The obstacle generates at least partial rotation of said object by friction between its said adherent part and the object moving in contact with said adherent part, and when the object continues its movement and passes said obstacle.

[0035] It is thus possible for said reading program to analyze the photos received and corresponding to the passage of a product through the reading zone, and to select the photo comprising the visible marking for its reading and the tracking of the product.

[0036] Finally, the invention also relates to a kit for reading a marking on a convex object, said device comprising at least one lighting device comprising a plurality of light sources arranged along a curved line in a support, and configured to illuminate with a concave light wall in the shape of a semicircle or an arc of a circle, and preferably at least one camera or an optical reader and / or a marking reading program executable on a control terminal. BRIEF DESCRIPTION OF THE FIGURES

[0037] Other advantages, aims and particular characteristics of the present invention will emerge from the following non-limiting description of at least one particular embodiment of the devices and methods which are the subject of the present invention, with reference to the appended drawings, in which: • [Fig.l] schematically illustrates an example of an arrangement of a marking reading device of the invention for reading a marking on a wine bottle. • [Fig.2] schematically illustrates a top view of an arrangement of the reading device for reading a marking on a wine bottle, and the configuration of a curvature and concave light wall of the illumination by a plurality of light sources. • [Fig.3] illustrates a bottom and perspective view of a concave wall support incorporating lighting according to one embodiment of the invention • [Fig.4] illustrates a side view of the support of [Fig.3], and the angle of inclination of the concave wall. • [Fig.5] illustrates an example of engraved Datamatrix type marking, photographed using a device according to the invention. • [Fig.6] schematically illustrates a method and device for reading markings on a convex object moving on a conveyor belt according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0038] The present invention relates to a device and a method for reading markings affixed to convex objects having in particular reflective surfaces, such as two-dimensional tracking codes on glass bottles. The reading method of the invention is particularly useful for reading Datamatrix codes engraved on glass bottles, but can be used for reading any type of marking printed, engraved or affixed to any convex object, with a reflective surface or not, such as any type of bottle, flask, container or product with curved walls.

[0039] The reading method differs from existing solutions in that it proposes the direct reading of the markings from an optical reading axis centered and facing the marking. That is to say from an optimal positioning to allow the reading and interpretation of the marking. In order to allow this type of reading, the invention proposes the use of lighting configured to neutralize the parasitic reflections created on the reflective surface of the convex object on which the marking is present.

[0040] Advantageously, the neutralization of parasitic reflections is obtained by means of lighting defining a concave luminous wall, and having a curvature substantially following a curvature of said convex object at the level of its marking. This lighting makes it possible to perfectly illuminate and contrast a marking on a convex wall. Preferably, and in particular when the convex object has a reflective surface, said lighting is positioned above or above the camera, and with an angle a of inclination making it possible to direct the lighting towards said marking. However, this lighting will allow the reading and the capture in photo in optimal conditions of any marking on a convex object of reflective surface or not. When the object is not very reflective or not reflective, the lighting can be arranged possibly at the level of the camera.

[0041] Fig. 1 schematically illustrates an example of arrangement of a device 10 for reading markings on a highly reflective object, this device comprising at least one camera 4 and lighting 3. In this example, the convex object 1 corresponds to a wine bottle having a Datamatrix type marking 2 on its circular cylindrical wall with a reflective surface. The marking 2 is positioned facing the camera 4 and so that it is in the center of an area focal length of the camera, and that the normal of the center of said marking preferably coincides perfectly with a 4x observation axis of said camera. For its part, the lighting is positioned above the camera with an inclination angle a allowing a 3x lighting axis of the lighting to be directed towards the marking 2.

[0042] [Fig. 2] schematically illustrates a top view of the configuration of the curvature of the lighting 3 according to one embodiment of the device. In this embodiment, the lighting 3 incorporates a plurality of light sources 33 arranged along a curved line 32 substantially following the curvature of a portion of the circular cylindrical wall 11 of the wine bottle, i.e. a curved line 32 substantially parallel and concentric to a circular base of the wine bottle. In one embodiment, these light sources 33 are installed individually along said curved line 32 and together define the concave light wall of the lighting.

[0043] In another embodiment illustrated in [Fig. 3], the lighting 3 integrates said plurality of light sources 33 by means of a support 30 having a concave wall 31 on which a plurality of LEDs “light emitting diodes” are fixed (not visible in the figure), said concave wall being configured with the desired curvature for the arrangement of the light sources 33 and making it possible to follow a curvature of the convex object 1 and to define said concave light wall.

[0044] Preferably, said concave wall 31 also has an angle of inclination a ([Fig.4]) making it possible to direct the lighting at the level of the marking when it is illuminated from a high or low position with respect to the marking. Advantageously, this support 30 allows easy installation of the desired arrangement for the lighting and its angle of inclination. Alternatively, the inclination of the lighting can be defined during its installation by means of a support making it possible to adjust said angle of inclination. This angle of inclination is not limiting and can be adjusted on a case-by-case basis depending on the positioning of the lighting and the camera, and can be between 0° and 60°, preferably between 10° and 60°.

[0045] Preferably, the lighting incorporates a light diffusing screen 34 also matching the shape of said concave wall 31 and being backlit by said plurality of light sources 33. The diffusing screen may for example take the form of a curved plate inserted into slides of the lighting support to cover said concave wall and the light sources 33. The use of this lighting 3 with a concave light wall makes it possible to capture perfectly contrasted images of a marking on a convex surface. Advantageously, when the illuminated surface is reflective, the lighting 3 with a concave light wall makes it possible to neutralize any parasitic reflection in the area of ​​the marking, to capture perfectly contrasted images and to directly read the marking of the convex object. In the case of a Datamatrix engraved on a glass bottle, the lighting will be configured with an inclination which will make it possible to illuminate the patterns of the hollow marking in an image taken from the right 4x observation axis of the camera 4, that is to say the hollow marked modules of the Datamatrix code will light up and appear lighter in the photo. [Fig.5] illustrates a Datamatrix code 20 thus illuminated and captured in a photo according to the invention, the hollow patterns of which are observed in a lighter color.

[0046] A second object of the invention is to propose a reading device and method capable of reading markings on convex objects in motion and positioned randomly. The invention aims in particular at reading markings on products in motion on a conveyor belt of a product packaging line, and in which the products move one after the other at a high speed.

[0047] To this end, the invention proposes a method and a device for reading markings allowing the photo capture of a convex object from several viewing angles, and during its passage through a predefined reading zone 5 on a conveyor belt 50. In this embodiment illustrated in [Fig. 6], the reading device of the invention combines a plurality of cameras 4 and a plurality of lighting units 3 installed in height offset, and around a reading zone 5 of a conveyor belt 50. Said plurality of cameras 4 is installed on one side and another of the conveyor belt at a first height, and substantially at the level of a height at which the marking is positioned during the passage of the convex object through said reading zone.

[0048] Of course, a 4x observation axis of cameras is directed towards the reading zone 5, and said plurality of cameras is distributed on each side of the conveyor belt to observe said reading zone 5 from all possible viewing angles without obstructing the passage of the convex object. In the illustrated embodiment, four cameras are arranged on one side and the other of the conveyor belt and in an arcuate alignment making it possible to obtain different shots of the convex object. However, this arcuate arrangement is not limiting, the essential thing being that the cameras can capture as best as possible all the viewing angles of the reading zone through which the marking is likely to pass.

[0049] The lights 3 are installed at a second height above or above the first installation height of cameras 4, and with an angle of inclination a making it possible to direct their light towards a positioning height of the marking 2 on the convex object 1. Typically, these lights 3 are configured to partially encircle the reading zone with their concave light wall without obstructing the passage of the convex object.

[0050] In this embodiment, the reading device 10 of the invention also comprises a control terminal T making it possible to execute a reading program P. and tracking of the markings, and being connected to the plurality of cameras 4 and the plurality of lights 3, as well as to at least one object detector 6 for detecting the presence of the convex object in the reading zone. In particular, said plurality of cameras 4 and said plurality of lights 3 are configured to be activated simultaneously upon detection of an object in the reading zone by said at least one object detector 6. The cameras then transmit, preferably by wire, photos taken of the convex object from their different viewing angles.

[0051] According to one embodiment, the cameras and the lighting are activated in burst mode or continuously when an object is detected in the reading zone, and to deactivate when said object is no longer detected. In another embodiment, two object detectors are implemented, a first detector configured to detect the entry of the object into the reading zone and trigger the activation of the cameras in burst mode or continuously, and a second object configured to detect the exit of the object from the reading zone and the stopping of the cameras.

[0052] The control program P receives the different photos, and selects at least one photo comprising the marking and allowing its reading, extracts the information from the marking (such as a tracking code) and records at least said information in a tracking program, and optionally said photo.

[0053] This reading device and method make it possible to capture the marking in a photo, without the need for a step of positioning the object in front of a camera. In practice, this makes it possible to read the majority of markings positioned randomly when a product moves on the conveyor belt and enters the reading zone. However, in a small proportion of cases and when the marking is small, the marking may be positioned in a blind spot of the reading zone. The marking will therefore not be able to be read.

[0054] In order to solve this problem, the invention proposes installing an obstacle making it possible to generate a rotation of the object at the reading zone (see [Fig.6]). In particular, the obstacle 51 is installed on the trajectory of the convex object 1 so as to weakly resist the passage of the convex object 1, and comprises an adherent part intended to come into contact with said object. By "weakly resisting the passage of the convex object" is meant that the obstacle allows the object to continue to advance on said conveyor belt without disturbing its balance or causing it to fall. Said obstacle 51 opposes a weak resistance to the passage of the object 1 and gives it a new direction.

[0055] Advantageously, said obstacle generates at least a partial rotation of said object by a friction effect during contact between said adherent part and the object 1 moving along said adherent part of the obstacle. The object thus rolls against the adherent part of the obstacle in a direction imposed by the direction of the obstacle 51.

[0056] The obstacle thus generates a partial rotation of the object allowing said object to be controlled at 360 degrees by said plurality of cameras 4.

[0057] In this example, the obstacle 51 is in particular a bar installed in a slightly diagonal direction with a distal end oriented towards the center of the control zone and towards the inside of the belt, and a proximal end oriented towards the entrance of the reading zone and the outside of the belt. Advantageously, the obstacle 51 is installed at a height close to the level of the belt, and has a low height, so that it does not obstruct the field of vision of the different cameras 4 or the lighting.

[0058] The adhesive part must cover at least the part of the obstacle 51 intended to come into contact with the object, or completely cover the obstacle. The adhesive part is made of a material or coating with non-slip properties such as rubber, silicone or other natural or synthetic polymers having adhesive and / or non-slip properties.

[0059] The present invention thus proposes a new method and device for reading markings capable of effectively reading markings affixed to reflective convex surfaces in motion, and positioned randomly. In addition, the device of the invention can be easily installed on existing product packaging lines, and adapt them for reading markings on reflective convex objects at a very affordable investment price.

Claims

Claims

1. Method for reading a marking (2) on a convex object (1), said method comprising the following actions: - illuminating said marking (2) by means of an extended lighting (3) defining a concave luminous wall, and having a curvature substantially following a curvature of said convex object (1) at the level of its marking, preferably substantially parallel to a curvature of said convex object at the level of its marking, and - reading and / or capturing in photo said marking (2) thus illuminated by means of an optical reader and / or a camera (4) positioned facing said marking, and with an observation axis (41) substantially normal and aiming at said marking so as to be able to read the marking (2).

2. Method according to claim 1, in which said convex object (1) has a reflective and / or transparent surface and said lighting (3) is installed facing the marking (2) in height offset with said camera, and is inclined at an angle (a) to illuminate with incident radiation (I) said marking.

3. A reading method according to claim 1 or 2, wherein said lighting (3) comprises a plurality of light sources (33) arranged along a curved line (32) defining a curvature of said concave light wall (31) and being installed independently or fixed together on a support (30).

4. Reading method according to claim 3, wherein said plurality of light sources (33) is fixed on a support (30) having a concave wall (31) allowing said plurality of light sources (33) to be arranged and fixed along said curved line, and said support (30) preferably incorporates a light diffusing screen (33) also matching the shape of said concave wall (31), and being arranged on a front face of said support and backlit by said plurality of light sources (33).

5. Reading method according to one of the preceding claims, in which said marking is engraved on a convex object (1) having a circular cylindrical shape, and the concave luminous wall of said lighting (3) has a semi-circle or arc shape, preferably substantially concentric with the convex object (1).

6. Reading method according to one of the preceding claims, in which said convex object (1) is a glass bottle, and said marking (2) is a Datamatrix (20) engraved in the glass.

7. Reading method according to claim 6 in which the engraved Datamatrix (20) consists of depressions, such as semi-spherical depressions, and the illumination (3) inclined at an angle (a) generates incident radiation (I) which produces a reflection (R) in each depression and which is detected by said optical reader and / or camera (4) placed in the axis normal to the marking (2).

8. Reading method according to claim 7, wherein said convex object (1) is rotated on itself and in the axis of the lighting and said optical reader and / or a camera (4) so that at a moment of rotation the incident lighting (I) meets the marking (2) and the reflection (R) on the marking is directed towards the reader or the camera (4).

9. Reading method according to one of claims 1 to 8, wherein said convex object (1) moves on a conveyor belt (50), and the reading of the marking (2) comprises the passage of said convex object (1) through a reading zone (5) of said conveyor belt (50), said reading zone (5) comprising on one side and on the other: - a plurality of cameras (4) arranged and configured to capture a photo of said convex object (1) from several viewing angles as it passes through said reading zone (5), and - at least one of said lightings (3) configured to illuminate the convex object (1) as it is captured as a photo by said cameras (4).

10. Reading method according to claim 9, said method comprising the analysis of the photos taken by said cameras (4), and the selection of at least one photo comprising the marking (2) of the convex object allowing its reading.

11. Reading method according to one of claims 9 or 10, wherein said lightings (3) installed on one side and another of the reading zone (5) are configured to partially encircle the reading zone (5) with their concave luminous wall (31), and are preferably installed in height offset with said plurality of cameras and inclined at an angle to illuminate with incident radiation (I) said marking.

12. Reading method according to one of claims 9 to 11, in which the reading zone (50) comprises an obstacle (51) comprising a adherent part in a trajectory of the convex object and being configured to weakly resist the passage of said convex object (1), and said obstacle generates at least partial rotation of said object by friction between its said adherent part and the object moving in contact with said adherent part, and when the object continues its movement and passes said obstacle (51).

13. Device (10) for reading a marking on a convex object (1) of circular cylindrical shape at the level of said marking, said device comprising at least one camera or optical reader (4) and lighting (3) installed at the level of a reading zone of a conveyor belt, characterized in that the lighting (3) defines a concave luminous wall (31) having a curvature substantially following a curvature of said convex object (1) at the level of its marking, and preferably said lighting is inclined at an angle (a) with respect to an observation axis of said at least one camera or optical reader.

14. Reading device (10) according to claim 13, wherein the lighting (3) lighting (3) comprises a plurality of light sources (33) arranged along a curved line (32) defining a curvature of said concave light wall (31) and being installed independently or fixed together on a support (30).

15. Reading device according to claim 14, wherein said plurality of light sources (33) is fixed on a support (30) having a concave wall (31) allowing said plurality of light sources (33) to be arranged along said curved line (32), and preferably incorporates a light diffusing screen (33) also matching the shape of said concave wall (31).

16. Device (10) for reading a marking according to one of claims 13 to 15, said device comprising a plurality of cameras (4) and at least two of said lightings (3), each lighting defining a concave light wall in the shape of a semicircle or an arc of a circle.

17. Reading device (1) according to one of claims 13 to 16, said device comprising a marking reading program (P) executable on a control terminal (T), at least one presence detector (6), a plurality of cameras (4), and at least two of said lightings (3), and -said plurality of cameras (4) and said at least two lights (3) are configured to activate simultaneously upon detection of an object by said object detector, and -said plurality of cameras is configured to transmit photos taken upon detection of an object to said marking reading program (P).

18. Kit (10) for reading a marking on a convex object (1), said device comprising at least one lighting (3) comprising a plurality of light sources arranged along a curved line in a support (30), and configured to illuminate with a concave light wall in the shape of a semicircle or an arc of a circle, and preferably at least one camera (4) or an optical reader and / or a marking reading program (P) executable on a control terminal.

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