The invention relates to an apparatus and a method for detecting, in particular, the outline, the orientation and the location of a three-dimensional product resting by gravity on a work surface in one of two possible positions, which are an upright position or an upside-down position.

The invention relates more particularly to the sorting and storing of blister-packs for ophthalmic lenses, also called contact lenses.

BACKGROUND OF THE INVENTION

An example of such a blister-pack design is described and shown in document US-5.609.246, which relates to a blister-pack for an ophthalmic lens with a lower part with a general shape of a hollow shell that is open in its upper face and a top lid for covering and closing a hollow chamber comprising the ophthalmic lens and a sterile preservation solution.

The upper covering and closing lid is substantially flat and sealed in a removable fashion on the lower shell.

The lower shell is generally made of a transparent or translucent plastic, whereas the upper lid is, for example, made of aluminium foil that prevents, in particular, the passage of light.

The design of this type of blister-pack is such that it is normally configured to rest “upright” on a substantially horizontal surface, with its lower shell resting on this surface, and its upper covering and closing lid oriented upwards.

The upper closing and covering lid is roughly flat so that the blister-pack can also rest in an “upside down” position on said horizontal surface, with its shell oriented upwards.

These blister-packs feature many variants in terms of design, dimensions and shape, so that, when viewed from above, they have different peripheral outlines, the outline corresponding substantially to that of the upper peripheral edge of the lower shell and, by complementarity, to that of the upper covering and closing lid.

Therefore, the outline can be rectangular with rectilinear sides, rectangular with two rounded convex opposite side, generally elliptical, etc. For each blister-pack it is therefore possible to identify a specific outline as well as a main axis enabling determination of the angular orientation of the blister-pack about a vertical axis.

On its free upper face, the upper covering and closing lid features a list of information, of data and of decorative elements that are specific to each blister-pack, and that constitutes a set of individual information that enables identification of each blister-pack.

When the blister-pack is resting in an upright position, the visible information can, in particular, comprise an identification bar code, a commercial brand, an alphanumerical identification relating to the type of ophthalmic lens contained in the blister-pack, the ophthalmic correction parameters, the expiry date, etc.

It is therefore possible to consider identifying individually and in an automated manner any blister-pack, in particular by“reading” at least a part of this information.

In order to automate the various steps of sorting, storing, batch- preparation, shipping, etc. it has been necessary to implement automated and robotised installations that require the ability to use, reliably, means to store and transfer the concerned blister-packs.

It appears that the automated handling and treatment, as well as the storage of this type of product are made particularly complex by its design and the variety of its shapes and dimensions.

This is, in particular, the case when the purpose is the automated sorting of bulk batches of such blister-packs to subsequently place each blister- pack upright in a transport and storage receptacle, open in its top part, the receptacle having the smallest possible dimensions to allow the storage of the largest amount possible of sorted and individualised blister-packs in a storage facility.

Each receptacle is delimited by several vertical walls that retain laterally a blister-pack placed on the bottom wall, and the outer face of at least one of the side walls features an identification marking of the receptacle, in particular by optical reading.

Furthermore, these operations of sorting and pairing each blister- pack with a receptacle must be conducted at a high frequency, for example of more than a thousand blister-packs per hour.

Document US5568715 proposes determining whether each automatically-filled blister-pack actually contains an ophthalmic lens, using an image-analysis method of each blister-pack by transparent illumination through the translucent shell to achieve maximum contrast and uniformity, each blister- pack having been positioned upright in a known position with respect to a support, itself arranged in a known and fixed position with respect to the image acquisition means. This document does not provide any information relating to the processing of bulk batches of blister-packs.

SHORT SUMMARY OF THE INVENTION

The invention proposes a method for determining the outline and the location of a three-dimensional product resting by gravity on a work surface in one of two possible positions, which are an upright position or an upside- down position, the method comprising:

- a step of acquiring a first image enabling determination of at least the outline in a top view of the product;

- a step of analysing this first image to recognise the outline of the product;

- a step of acquiring a second image of a top view of the product;

- a step of analysing this second image to determine the upright or upside-down position of the product.

According to other characteristics of the method:

- the analysis step of the first image enables determination of the orientation from the top view of the product and/or its geometric centre of gravity;

- the analysis step of the first image enables determination of the location of the product on the work surface;

- the analysis step of the second image enables determination of the orientation from the top view of the product and/or its geometric centre of gravity;

- the analysis step of the second image enables determination of the location of the product on the work surface;

- the analysis step of the second image enables identification of at least some information among the individualised information relating to the product that is visible when the product is in an upright position;

- the step of acquiring a first image is achieved by illuminating the product from below through a transparent or translucent work surface by means of a first source for underneath lighting the product through the work surface, and by acquiring this first image by means of a top camera arranged above the work surface;

- the step of acquiring a second image is achieved by illuminating the product from above, and by acquiring this second image by means of a camera arranged above the work surface; - the step of acquiring the first image and the step of acquiring the second image are achieved by image acquisition using a shared top camera arranged above the work surface;

- the product is a blister-pack containing an ophthalmic lens and comprising a lower shell and an upper closing lid;

- the blister-pack contains an ophthalmic lens.

The invention proposes an apparatus for the implementation of the method for detecting the outline and the location of a three-dimensional product according to the invention, this apparatus comprising:

- means to produce a first image enabling determination of at least the outline of the product;

- means to acquire this first image;

- means to analyse this first acquired image to recognise the outline of the product;

- means to produce a second top view image of the product;

- means to acquire this second image;

- means to analyse this second image to determine the upright or upside-down position of the product.

According to other characteristics of the apparatus:

- the means to produce a first image and the means to analyse this first acquired image enables determination of the orientation from a top view of the product and/or of its geometric centre of gravity;

- the means to produce a first image and the means to analyse this first acquired image enables determination of the location of the product on the work surface;

- the means to produce a second image and the means to analyse this second acquired image enables determination of the orientation from a top view of the product and/or of its geometric centre of gravity;

- the means to produce a second image and the means to analyse this second acquired image enables determination of the location of the product on the work surface;

- the means to produce a second image and the means to analyse this second acquired image enables identification of at least some information among the individualised information relating to the product that is visible when the product is in an upright position;

- the means to produce the first image comprises a transparent or translucent work surface, and a first source for lighting underneath the product through the work surface, and the means to acquire this first image comprising a top camera arranged above the work surface; - the means to acquire a second top view image of the product comprises a camera arranged above the work surface;

- the means to acquire a first image and the means to acquire a second top view image of the product comprises a shared camera arranged above the work surface;

- the means to produce a second image comprise a second light source above the product resting on the work surface;

- the work surface belongs to a vibrating plate controlled to vary the position of the product on the work surface;

- the surface comprises a controlled articulated arm for gripping of a product comprising means to change the angular orientation of the gripped product by rotation about a vertical axis;

- the apparatus comprises a station where the product is deposited in a transport receptacle, after the step whereby the articulated arm grips the product and corrects its orientation;

- the apparatus comprises the means to successively control the means to acquire a first image, then the means to acquire a second image and to repeat this successive command after each operation whereby a product is gripped by the articulated arm;

- the product is a blister-pack containing an ophthalmic lens and comprising a lower shell and an upper closing lid.

BRIEF DESCRIPTION OF THE FIGURES Other characteristics and advantages of the invention will be made clearer upon reading the following detailed description, with reference to the appended drawings, in which:

- figure 1 is a schematic and perspective view of the main components of an embodiment example of an apparatus according to the invention ;

- figure 2 is a view similar to that of figure 1, which shows some of the components of figure 1;

- figure 3 is a schematic and perspective top view of an example of a blister-pack for an ophthalmic lens shown in the“upright” position;

- figure 4 is a perspective view similar to that of figure 3 wherein the blister-pack is shown in the“upside down” position;

- figure 5 is a top view of the blister-pack shown in figure 3;

- figure 6 is an example of a first image acquired according to the invention showing a series of blister-packs to be sorted and stored; - figure 7 is an example of a second image acquired according to the invention showing the same series of blister-packs as that shown in figure 6, in the same positions, orientations, and locations;

- figure 8 is a schematic and perspective view that shows the apparatus of figure 1 associated with an adjacent conveyor for the transport and storage of receptacles for blister-packs with a handling articulated and robotised arm;

- figure 9 is a schematic and perspective view of the conveyor of figure 8 with two receptacles each containing one blister-pack;

- figure 10 is a top view of a receptacle containing a blister-pack of the same type as that shown in figures 3 to 5;

- figure 11 is a schematic cross-section view of the main components of the installation shown in figure 2.

DETAILED DESCRIPTION OF THE FIGURES

In the following description, elements featuring identical structures or similar functions are designated by the same references.

In the following description, the longitudinal, vertical and transversal orientations are designated by the “L, V, T” trihedron of the figures. A horizontal plane is thereby defined and extends longitudinally and transversally. The longitudinal axis is oriented from the back to the front.

Figures 3 to 5 show an example of a blister-pack BP for an ophthalmic lens constituted of a lower shell 20 made of a transparent or translucent plastic material that delimits a lower chamber 22, in this case delimited by a flat lower wall 24 configured to rest on a horizontal surface, and by a side wall 26.

The side wall 26 is extended by a peripheral annular upper edge 28 that extends in a horizontal plane and that delimits an open flat horizontal upper face 29 of the lower shell 20.

This open upper face 29 is closed by a lid 30 that is glued and removable to access the ophthalmic lens contained in the chamber 22.

The lid 30 comprises an external upper face 32 that is substantially flat.

The side profile of the edge 28 defines the outline C of the blister- pack BP from a top view, as shown in figure 5.

From a top view, the blister-pack BP is therefore characterised by the shape and dimensions of its outline C, and by the surface delimited by its outline C. The outline C in this case has a general rectangular shape with substantially semi-circular convex rounded opposite smaller sides.

The outline C features a main axis A that is in this case an axis of symmetry.

Other geometric and physical parameters of a blister-pack, such as the blister-pack BP, comprise its weight, its geometric centre of gravity, etc.

For the purpose of simplifying representation in figures 3 and 5, the outline or the peripheral edge of the lid 30 corresponds, in this case, exactly to the outline C of the blister-pack BP.

However, the dimensions of the lid 30 can be slightly smaller than that of the peripheral annular edge 28 so that there is a clearance between these two outlines, for example along the perimeter of the lid 30.

Figure 10 shows a receptacle B for the transport, transfer, and storage of an individualised blister-pack BPi, which is, in this case, a blister- pack similar to the blister BP that has just been described.

The dimensions of the receptacle B are such that it is configured to contain any type of blister-pack to be stored in an automated manner.

The receptacle B is, for example, a unit formed by moulding of a plastic material and it has a rectangular cuboid shape.

The receptacle B comprises a bottom wall 40 and four side walls 42 and 44, by pairs of opposite walls.

The upper face 46 of the receptacle B is vertically open upwards so as to allow the introduction of a blister-pack vertically from the top.

At least one of the vertical side faces, in this case a greater face 44, comprises an individualised identification marking of the receptacle B, here in the form of a bar code MB that can be read, in a known manner, by any camera designed for that purpose.

As can also be seen in figure 10, the upper face 32 of the lid 30 of the blister-pack BPi housed in the receptacle B comprises various information relating to the blister-pack and its content, in particular including, but not limited to, the following: a bar code MBPi; the commercial brand 48 of the manufacturer; the expiry date 50 for the use of the ophthalmic lens; the data 52 relating to the optical and dimensional characteristics of this ophthalmic lens; etc.

Each blister-pack BPi therefore comprises an individualised marking in the form of a bar code MBPi, which, together with the bar code MB of the receptacle B enables an unequivocal pairing of a blister-pack BPi with a receptacle B to which it is associated for the duration of storage. In other words, the reading of the marking MB of the receptacle B also enables identification of the blister-pack BPi it contains, to which it was paired during the“filling” of the receptacle B with said blister-pack BPi.

For the automated filling of a receptacle with a blister-pack from a bulk batch of blister-packs of all types and models, they have to be taken one- by-one and individually recognised, to associate each gripped blister-pack with a receptacle.

For this purpose, the invention proposes an apparatus such as that shown, in particular, in figures 1, 2 and 11.

Figures 1 and 2 show an apparatus 50 according to the invention that enables selecting and individually gripping blister-packs BPi from a bulk batch of blister-packs to be sorted, for the purpose of subsequently pairing each gripped blister-pack with an associated storage receptacle.

The apparatus 50 comprises a lower supporting frame 52 that carries a work table 54 above which the main components, units and subunits of the apparatus are arranged.

The work table 54 extends globally longitudinally and essentially comprises a rear section 58 and a front section 60.

The invention also comprises a vibrating storage hopper 62 that is arranged vertically above the rear section 58 of the lower work table 54.

The storage hopper 62 is configured to receive the batch bulk of blister-packs and its front-end face 64 is open to enable, in a known manner, to progressively evacuate, in limited quantities, a series of blister-packs that leave the hopper 62, falling vertically out of the hopper 62.

The front section 60 of the lower work table 54 is a work tray that comprises an upper work surface 66 with a rectangular shape, which, when the work tray is stopped, extends in a horizontal plane.

The work table 54 comprises means - not shown - to vibrate the work tray 60 so as to “shake” the blister-packs resting on the work surface 66, in particular to turn them over.

Indeed, as seen in figures 1 and 2, a blister-pack can be placed in the upright position (BPr) or be placed upside down (BPv).

When the work tray 60 is vibrated, the blister-packs“jump” and fall onto the work surface 66 in one or the other of the two positions, upright or upside down.

The vibrating of the work tray 60 also enables distribution of a series of blister-packs - which have fallen from the hopper 62 - on the work surface 66.

The apparatus 50 also comprises a side support frame 68 that is arranged here along one of the longitudinal sides of the lower frame 52. At its upper end, the side frame 68 supports a horizontal upper plate 70.

As can be seen in figures 2 and 11, in its centre, the upper plate 70 carries a camera 71 for image acquisition purposes, which, through a central hole 72, enables acquisition (or capture) of digital pictures from a top view of the work surface 66, which is delimited by a square (or rectangular) perimeter; the field of view of the camera corresponding to the dimensions of the work surface 66.

As shown schematically in figure 11 and, according to the invention, to allow the acquisition of images for the purpose of capturing in succession two different images of the work surface and the blister-packs it supports, the work surface 66 is transparent or translucent and it can be illuminated from below, by means for example of a first controlled light source LS1 that is arranged inside the work tray 60.

The first light source LS1 is controlled in a synchronised manner with the camera 71 to generate a light “flash” from underneath the work surface 66 and the corresponding acquisition of a first image I M 1.

According to the invention, to allow the acquisition of images aiming at capturing successively two different images of the work surface and the blister-packs it supports, the upper plate 70 houses a second controlled light source LS2, which is arranged inside the upper plate and illuminates from above the work surface 66, here for example through the lower wall 74 of the upper plate 70, which is transparent.

The second light source LS2 is controlled in a synchronised manner with the camera 71 to generate a light “flash” from above the work surface 66 and the corresponding acquisition of a second image IM2.

To individually take each blister-pack BPr placed in the upright position on the work surface 66, the apparatus also comprises an articulated and robotised arm 80, for example of the type described and shown in document EP-B1 -1.188.863.

Its design enables it to carry, at its free end, a gripping head 82 comprising, in particular, a suction cup 84 for the gripping of a facing blister- pack, in a controlled manner and by suction, and evidently for the release of a product that has been gripped or captured by the suction cup.

Furthermore, the gripping head 82 is able to move vertically in both directions under the effect of a cylinder with a vertical rod 86.

The design of the robotised arm 80 enables movement of the gripping head 82 in a horizontal plane and, in particular, to any precise location above the work surface 66, in particular to bring the gripping head 82 on top of a blister-pack that is to be gripped or captured. As can be seen in figure 8, along the longitudinal side of the lower frame opposite the side frame 68, the apparatus 50 comprises a horizontal conveyor 88 with a conveyor belt 90 travelling longitudinally from back to front following the direction of arrow F.

The conveyor 88 carries and guides a series of receptacles B to be filled, individually, with a blister-pack.

The station where a receptacle is filled - or where a blister-pack is placed in a receptacle - corresponds to the position of the receptacle B0, located furthest to the right, and immobilised in a controlled manner in this position. The immobilisation or stopping in this filling position of a receptacle is performed by blocking, in a longitudinal position, by a controlled sliding transversal finger 92.

After having been filled with a blister-pack at the station “B0”, the receptacle is released by the finger 92 and then travels in a longitudinal forward direction to a B1 position and beyond, to another station, not shown, comprising a side camera for the identification of the receptacle, and a top camera, for the identification of the blister-pack contained in the receptacle B.

As can be seen in figure 6, the first captured image IM1 is obtained by illumination from below of a series of seventeen blister-packs that have been poured onto the work surface 66 from the hopper 62 and that have been randomly distributed in terms of their location on the surface, in terms of their upright or upside down position, and in terms of their orientation.

In these conditions, the image acquisition with “backlighting” provides a first “black and white” image IM1 that reveals the continuous, accurate and exact outline C of each blister-pack, with the exception of overlapping blister-packs (here in the form of three overlapping blister-packs).

A step is performed whereby the outline C of the blister-pack BPi is recognised by analysis of this first image I M 1.

The analysis of this first digital image IM1 using known and conventional image analysis methods can allow - at least for blister-packs that do not overlap - to conduct a comparison with data contained in a database to recognise each blister-pack.

For each known model of blister-pack to be sorted, the database contains data comprising, in particular, its geometric outline C from a top view, with its dimensions, an orientation and position of the main axis with respect to the outline C, the surface delimited by the outline C, the geometric centre of gravity of the blister-pack, etc.

Regardless of the need to rely on this database, and given the precision of the first image IM1 in “black and white”, an analysis of this first image enables, for each blister-pack, calculation of its geometric centre of gravity, the orientation of its main axis A and its location in the plane of the image.

Therefore, a step is performed whereby the orientation, from a top view, of the blister-pack BPi and/or its geometric centre of gravity is determined.

A step is therefore performed whereby the location of each blister- pack BPi is determined on the work surface 66.

When the analysis of the first image is completed, each blister- pack thereby recognised is recorded as a blister-pack to grip on the work surface 66, along with its various geometric data.

Unrecognised blister-packs are then evacuated from the work surface 66.

However, the analysis of the first image IM1 does not enable determination of whether a recognised blister-pack is in an upright position or in an upside-down position.

Therefore, the method for determining the position and orientation of each blister-pack in an upright position requires a second image acquisition enabling capture of a second digital image IM2, such as that shown in figure 7.

This second image IM2 is obtained by illuminating from above the series of seventeen blister-packs that have been poured onto the work surface 66, and without their positions, locations, orientations etc. having been changed since the acquisition of the first image I M 1.

As is shown schematically in figure 6, the lighting conditions from above the work surface 66 of the blister-packs present on the surface are such that the outlines of each blister-pack can be “blurred”, and even “not visible”. This is due to the constitution of the blister-packs and the materials used for the lower shell 20 and for the lid 30 which, among other factors, result in reflection phenomena that are detrimental to the accuracy of the image.

However, the analysis of the second image IM2 enables easily determining whether each blister-pack - which has already been recognised - is in an“upright” position or in an“upside down” position.

A step is therefore performed whereby the upright or upside-down position of the blister-pack BPi is determined by analysis of this second image IM2.

The analysis step of the second image IM2 enables performing a step whereby at least some information among the individualised information relating to the blister-pack BPi that is visible when the product is in an upright position is identified;

Therefore, following this double successive analysis of two acquired images IM1 and IM2, the processing and analysis means of the images enables determination of a set of eleven “upright” blister-packs BPr that are gripped by suction by means of the suction cup 84 that will cooperate with the substantially-flat external upper face 32 of the lid 30.

Inversely, the double analysis of the images enables determination of the set of six “upside down” blister-packs BPv that cannot be gripped by suction by means of the suction cup 84 because of the complex and irregular profile of the lower shell 24 oriented upwards.

Furthermore, for each recognised and upright blister-pack BPr its geographic location and angular orientation in the plane of its main axis, and possibly the position of its geometric centre of gravity, are known.

If these parameters are not determined during the analysis of the first image I M 1 , they can be determined during the processing and analysis of the second captured image IM2.

The processing of a series of blister-packs on the work surface 66 can then continue by means of the articulated robotised arm 80 that will grip or capture individually and successively each of the blister-packs BPr in the upright position, or at least those among these BPr blister-packs that do not overlap.

In addition to the transfer of each blister-pack above an empty receptacle“B0” as shown in figure 8, the gripping head 82 performs an angular reorientation of the gripped blister-pack so that its main axis is oriented substantially in parallel with the greater longitudinal dimension of the receptacle, before the blister-pack is deposited in the receptacle.

Optionally, between each individual gripping of a blister-pack, the step of acquiring two successive images IM1 and IM2 can be repeated to verify that the gripping of the blister-pack has not caused changes to the other blister- packs of the series being processed.

When the recognised blister-pack gripping operations are completed, the remaining blister-packs that are on the work surface 66 are shaken, in particular to cause them to turn over, so that a new group of “upright” blister-packs can be obtained.

When it is deemed that the number of blister-packs remaining on the work surface is insufficient 66, the pouring of a new series of blister-packs BPr and BPv is performed onto the work surface 66.

Each blister-pack housed in its associated receptacle is then brought to the station, not shown, comprising a side camera for the identification of the receptacle and a top camera for the identification of the blister-pack contained in the receptacle B. This identification is carried out by reading all or part of the various information relating to the blister-pack and to its content present on the upper face 32 of the lid 30 (bar code MBPi; commercial brand 48 of the manufacturer; expiry date 50; data relating to the optical and dimensional characteristics of the lens, etc.).

The invention is not limited to the processing of blister-packs, of the type mentioned above, containing each exclusively one or several ophthalmic lenses, a blister-pack being able to contain any other type of object.