EP2247407A1

EP2247407A1 - Method for preparing an ophthalmic lens with specific machining of the fitting rib thereof

Info

Publication number: EP2247407A1
Application number: EP09715200A
Authority: EP
Inventors: Ahmed Haddadi
Original assignee: Essilor International Compagnie Generale dOptique SA
Current assignee: EssilorLuxottica SA
Priority date: 2008-01-28
Filing date: 2009-01-09
Publication date: 2010-11-10
Anticipated expiration: 2029-01-09
Also published as: EP2247407B9; WO2009106765A1; FR2926896A1; FR2926896B1; US20100309430A1; US8556419B2; ATE515367T1; EP2247407B1

Abstract

A method of preparing an ophthalmic lens for mounting in a surround of an eyeglass frame includes an acquisition step of acquiring a first longitudinal profile of the surround and an orientation parameter of the first longitudinal profile relative to a horizon line or a verticality line of the surround, and an edging step of edging the ophthalmic lens so as to form a generally profiled engagement ridge of desired section that extends along a second longitudinal profile (25) that is derived from the first longitudinal profile and of orientation that is derived from the orientation parameter. The method includes a determination step of determining at least one singular portion (Z1-Z12) of the second longitudinal profile as a function of the orientation parameter. During the edging step, the engagement ridge is locally pared away in the singular portion.

Description

PROCESS FOR PREPARING AN OPHTHALMIC LENS WITH SPECIFIC MACHINING OF SA

BOOT RIB

TECHNICAL FIELD TO WHICH THE INVENTION REFERS

The present invention relates generally to the field of eyewear and more specifically to the preparation of ophthalmic lenses for interlocking in circled spectacle frame surrounds.

TECHNOLOGICAL BACKGROUND

The technical part of the optician's profession is to mount a pair of corrective ophthalmic lenses on a frame of rimmed spectacles selected by a wearer. This assembly is broken down into three main operations:

the acquisition of the shape of the inner contours of the frames of the frame,

the centering of each lens, which consists of positioning and orienting each lens correctly facing each eye of the wearer, then

- The machining of each lens which consists of cutting or contouring its contour to the desired shape, given the shape of the surrounds and defined centering parameters.

The practical objective of the optician is to cut the ophthalmic lens so that it can mechanically and aesthetically adapt to the shape of the corresponding entourage of the selected frame, while ensuring that the lens exercises at best the optical function for which it was designed.

The machining operation comprises in particular, in the case of rimmed frames, a beveling step for forming on the edge of the lens an interlocking rib, commonly called bevel, adapted to fit into a groove, commonly called a sucker, which runs along the inner face of the corresponding entourage of the mount.

In particular, the two acquisition and machining operations must be carried out carefully so that the lens can perfectly fit into its surroundings, effortlessly and "first time", that is to say without requiring resumption of machining.

To acquire the shape of the bezel, it is generally used a contour reading device having a feeler which comes to raise the shape of the bezel. However, at the end of this probing, there are errors in raising the shape of the contour. These errors are inherent to the reading device which may have insufficient resolution, assembly defects or be damaged or unregulated. In addition, the deformations of the frame during the probing of the bezel (due to the support of the probe on the bezel) also generate errors. At the end of the machining operation, clipping errors are also observed, so that the effective shape of the edge of the lens does not correspond exactly to the desired shape. These errors are also inherent in the trimming apparatus which may have insufficient resolution, assembly defects or a worn-out wheel. In addition, the bending deformations of the lens (due to the support of the grinding wheel against the edge of the lens during its machining) also generate errors, as well as the phenomena of expansion of the lenses during their machining.

Ultimately, in view of these errors and inaccuracies, a lens thus machined has a contour that rarely corresponds exactly to the outline of the bezel of his entourage. It may then be too large, which forces the optician to perform a tedious recovery of the machining of the nesting rib, too small.

In order to increase the rate of correctly cut lenses "at first glance", it is known to correct the defects of acquisition and trimming devices, so as to increase their resolutions and that they take into consideration a larger number of parameters. It is also known to calibrate these devices at short intervals. However, these methods are long, complex and expensive to implement. The parameters currently taken into consideration are also not exhaustive. As a result, the rate of properly machined lenses of the "first shot" is unsatisfactory to date.

In addition, the lenses considered as mountable in their surroundings are, to a large extent, slightly too large compared to their surroundings, so that once nested in their surroundings, they are mechanically constrained. As a result, these lenses are weakened and their treatment layers are likely to degrade more rapidly. In addition, these mechanical stresses slightly modify the optical characteristics of the lens, which can cause discomfort for the wearer.

It is also known to acquire the shapes of the bezels of the surroundings of an eyeglass frame by means of a database register comprising a plurality of records each associated with a model of glasses. eyeglass frames. However, due to manufacturing dispersions, it is observed that two spectacle frames of the same model never have exactly the same shape. Therefore, the shapes acquired in the database are generally slightly different from the actual shapes of the bezel crates selected by the wearer. As a result, the lenses machined according to these acquired shapes are not always mountable in the surroundings of the selected frame, so that it is often necessary to resume the machining of their interlocking ribs.

It is also known to acquire the shape of the bezel of an entourage of an eyeglass frame according to the previously acquired shape of the bezel of the other entourage of this spectacle frame, assuming that the two surrounds are symmetrical. However, due to manufacturing dispersions, it is observed that the two surrounds of the same spectacle frame are never really symmetrical. Consequently, the shape deduced by symmetry is generally slightly different from the actual shape of the bezel of the second circle. As a result, the lens machined according to this form deduced is not always mountable in the second surround of the frame, so that it is often necessary to resume machining its nesting rib.

OBJECT OF THE INVENTION In order to overcome the aforementioned drawbacks of the state of the art, the present invention proposes a process for preparing ophthalmic lenses making it possible to increase the probability that these lenses fit together correctly "at first glance" in their surrounded without being subjected to excessive mechanical stress. More particularly, there is provided a method for preparing an ophthalmic lens for mounting in an environment of a spectacle frame, comprising a step of acquiring a first longitudinal profile of said surround and a parameter of orientation of this first longitudinal profile relative to a horizon line or verticality of said entourage around an axis of orientation substantially perpendicular to a mean plane of said entourage, and a step of trimming the ophthalmic lens with formation on its edge. a generally profiled interlocking rib having a desired section and extending along a second longitudinal profile which is derived from the first longitudinal profile and whose orientation relative to the ophthalmic lens about said orientation axis is deduced from said parameter of orientation.

According to the invention, the method comprises a step of determining minus a singular portion of the second longitudinal profile as a function of said orientation parameter, and during the trimming step, the interlocking rib is formed to have a narrowed section in width and / or height on said singular portion. In a variant, during the trimming step, the interlocking rib is formed so that the second longitudinal profile is deductible from the first longitudinal profile by a mathematical law which is different on said singular portion than for the rest of the second longitudinal profile. , so that the average radius of curvature of this singular portion of the second longitudinal profile is increased with respect to the average radius of curvature that this singular portion would have presented if the mathematical law had been, on this singular portion, the same as for the rest the second longitudinal profile.

This compensates for the errors inherent in the operation of the reading and trimming apparatuses, not by increasing the accuracy of these devices, but rather by taking these errors into account by cutting off the interlocking rib in singular portions that are particularly sensitive to assembly of the lens with its mount.

These singular portions are zones of interference between the bevel and the surrounding of the frame during the engagement of the lens in its surroundings. Their positions are, according to the invention, deduced from the orientation of the second longitudinal profile relative to the reference frame of the spectacle frame. This deduction can therefore be easily performed with the aid of a simple calculation algorithm, so that the deduction step can be implemented particularly quickly. The trimming of the interlocking rib in these portions allows that once the lens is nested in its surroundings, the nesting rib is not in contact with the bezel on its entire periphery but rather that there appear spaces between the engagement rib of the lens and the bezel of the entourage of the frame, at the level of said singular portions. Therefore, these singular portions are so-called portions of freedom that induce a free play between the nesting rib and the bezel.

Consequently, if the interlocking rib has erroneously been machined to an outline that is slightly too large compared to the outline of the bezel, these spaces allow the surround to locally deform to compensate for this machining error. In this way, the lens can be nested in its surroundings, without the latter inducing excessive mechanical stress on this lens.

To trim the interlocking rib, it is possible to locally narrow the section of the engagement rib of the lens at the singular portions of the second longitudinal profile. We understand then that the nesting rib will be able to engage deeper in the bezel of the entourage at these singular portions.

It is also possible, to trim the interlocking rib, to calculate the shape of the second longitudinal profile in a particular way at the singular portions of the second longitudinal profile, so that the radius of curvature of the second longitudinal profile is locally increased. In this way, during the clipping step, the lens is locally milled more deeply to reveal, when mounting the lens in the surrounding area, the slight space between the frame and the edge of the frame. lens. DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

The description which follows, with reference to the accompanying drawings, given by way of non-limiting example, will make it clear what the invention consists of and how it can be achieved.

In the accompanying drawings: FIG. 1 is a perspective view of a device for reading bezel contours of eyeglass frames;

FIG. 2 is a diagrammatic view of an ophthalmic lens held in a trimming apparatus provided with a beveling wheel;

- Figures 3 to 5 are side views of three beveling wheels; FIG. 6 is a front view of a non-cut-away ophthalmic lens, on which is represented a longitudinal profile of a bezel of an entourage of an eyeglass frame, a longitudinal profile of a nesting rib that the ophthalmic lens will present after trimming, and a boxing frame circumscribing the longitudinal profile of the interlocking rib; - Figures 7A and 7B are sectional views of the slices of two ophthalmic lenses cut in two different embodiments;

FIGS. 8A and 8B are cross-sectional views of a nesting rib of an ophthalmic lens fitted into a bezel of an eyeglass frame at a section located outside a singular portion and a section located in a singular portion; and

FIGS. 9 to 16 are plan views of the longitudinal profile of the interlocking rib of the ophthalmic lens of Figure 6 and its singular portions.

The present invention aims to facilitate and improve the quality of the interlocking of an ophthalmic lens in a surrounding of a spectacle frame.

We will therefore be more particularly eyeglass spectacle frames 10 (Figure 1) having two surrounds 11 which are connected to each other by a bridge and which are each equipped with a branch. Conventionally, each surround 11 is internally traversed by a generally profiled groove, generally in the form of dihedron, commonly known as a bezel. This bezel extends along a curvilinear longitudinal profile 12. Such a bezel 13 is shown in section in FIG. 8A.

This longitudinal profile 12 corresponds to one of the strands of the bezel, which extends on one and / or the other of the sides of this bezel and which is substantially parallel or coincides with the bottom edge of the bezel.

We can define with respect to this longitudinal profile 12 a horizon line

A2 (Figure 6) which is substantially horizontal when the eyeglass frame 10 is carried by the wearer in the orthostatic position, that is to say when the wearer is standing and he holds his head straight. The horizon line A3 here corresponds more particularly to the straight line which passes opposite the two pupils of the wearer.

It is also possible to define with respect to each surround 11 an average plane which is orthogonal to the two branches of the spectacle frame 10 when they are in the deployed position and which is tangent to the bridge of this frame. Finally, it is possible to define a line of verticality A3 (FIG. 6) which is substantially vertical when the spectacle frame 10 is carried by the wearer in an orthostatic position and which passes through the plane of symmetry of the eyeglass frame.

As shown in Figure 2, the ophthalmic lens 20 has a front optical face 21 convex and a concave rear optical surface 22, and a peripheral edge 23 whose initial contour 2OA (Figure 6) is generally circular.

As shown in FIGS. 7A, 7B and 8A and 8B, this ophthalmic lens is intended to include, after machining its edge 23, an engagement rib 24 extending along a longitudinal profile 25; 27 curvilinear whose shape allows the nesting of the ophthalmic lens 20 in the entourage 11 corresponding spectacle frame 10.

This longitudinal profile 25; 27 corresponds to a line running along the edge 23 of the lens and which joins a defined point of each cross section of the nesting rib 24. Each of these points is here defined by a rule which is uniform for the whole cross-sections of the interlocking rib 24. By way of example, the longitudinal profile 25 may correspond to one of the strands of the interlocking rib 24, which extends over one and / or the other flanks of this interlocking rib and which is substantially parallel or coincident with the top of the nesting rib. As shown in FIG. 6, a box frame 26 can be defined relative to the longitudinal profile 25.

This boxing frame 26 is more precisely defined as the rectangle which, on the one hand, is circumscribed to the orthogonal projection of the longitudinal profile deduced

25 in the plane of the initial contour 2OA, and which, on the other hand, has two sides parallel to the horizon line A2 and two sides parallel to the line of verticality

A3.

This boxing frame 26 has, at the intersection of its two diagonals, a geometric center C1 through which passes a central axis A1 of the lens (Figure 2), also called orientation axis or blocking axis. The central axis A1 is substantially normal to the average plane of the surrounding 11 considered and passes through the geometric center C1. Device

To prepare such a lens, it is known to use a contour reading device 1 such as for example that shown in Figure 1. This device comprises an upper cover 2 covering the entire device except for a central upper portion accessible to the user, in which the spectacle frame 10 is arranged.

The contour reading device 1 is intended to record the shape of the contours of the bezels 13 of the surrounding areas 11 of this eyeglass frame 10. It comprises for this purpose a set of two jaws 3, one of which is movable, which are provided with movable studs 4 for clamping between them the eyeglass frame 10 in order to immobilize it.

In the space left visible by the central upper opening of the hood

2, a chassis 5 is visible. A plate (not visible) can move in translation on the frame 5 along a transfer axis D1. On this plate is rotatably mounted a turntable 6. This turntable 6 is therefore able to take two positions on the transfer axis D1, opposite each of the two surrounds 11 of the spectacle frame 10.

The turntable 6 has an axis of rotation B1 defined as the normal axis to the front face of the turntable 6 and passing through its center. It is adapted to pivot about this axis relative to the plate. The turntable 6 further comprises an oblong slot 7 in the form of an arc of a circle through which a probe 8 protrudes. This probe 8 comprises a support rod 8A with an axis perpendicular to the plane of the front face of the turntable 6 and, at its free end, a feeler pin 8B with an axis perpendicular to the axis of the support rod 8A. This finger 8B is intended to follow by sliding or possibly rolling the bottom of the bezel 13 of each of the two surrounds 11 of the eyeglass frame 10, moving along the light 7.

The contour reading apparatus 1 comprises actuating means (not shown) adapted, firstly, to slide the support rod 8A along the lumen 7 in order to modify its radial position R with respect to the B1 rotation axis of the turntable 6, a second part, to vary the TETA angular position of the turntable 6 about its axis of rotation B1, and, thirdly, to position the feeler finger 8B of probe 8 at an altitude Z more or less important with respect to the plane of the front face of the turntable 6. Each point palpated by the end of the feeler finger 8B of the probe 8 is then located in a corresponding cylindrical coordinate system. The coordinates of each probed point of the bezel 13 are then denoted rai, tetaai, za ,.

The contour reading apparatus 1 furthermore comprises an electronic and / or computer device 9 making it possible, on the one hand, to drive the actuating means of the contour reading apparatus 1, and, on the other hand, to acquire and record the coordinates rai, tetaai, zaι of each point palpated of the bezel 13.

In order to prepare the ophthalmic lens 20, it is also known to use a trimming apparatus 30 which is not the subject of the present invention. Such a clipping device, well known to those skilled in the art, is for example described in US 6,327,790 or marketed by the applicant under the trademark Kappa CTD.

As shown in Figure 2, such a trimming apparatus 30 generally comprises support means here formed by shafts 31 for holding and rotating the ophthalmic lens 20 around a locking pin A1 coincides with the central axis of the lens. Such a clipping apparatus further comprises clipping means here formed by a machining tool 32 rotatably mounted about an axis of rotation A4 which is here substantially parallel to the blocking axis A1, but which could also be inclined with respect to this axis .

The machining tool 32 and / or the shafts 31 are provided with two relative mobilities, including a radial mobility for modifying the spacing between the axis of rotation A4 and the blocking axis A1, and translational mobility. axial along an axis parallel to the blocking axis A1.

The trimming apparatus 30 further comprises an electronic and / or computer device (not shown) which is provided, on the one hand, with communication means with the electronic and / or computer device 9 of the contour reading device. 1, and, secondly, means for controlling the mobilities of the shafts 31 and of the machining tool 32. This electronic and / or computer device makes it possible in particular to control, for each angular position of the lens 20 around of the locking pin A1, the radial spacing between the machining tool 32 and the locking pin A1, as well as the axial position of the edge 23 of the lens relative to the working surface of the machining tool 32.

As shown more particularly in FIG. 3, the machining tool 32 is in this case constituted by a main grinding wheel 33 of shape, that is to say having, in the hollow, in the manner of a negative, a machining profile complementary to that to be obtained in relief on the side 23 of the lens to be machined. This main grinding wheel 33 is here of revolution about the axis of rotation A4 and is provided with a beveling groove 34 capable of forming on the flank 23 of the lens 20 an interlocking rib 24 (FIG. 8A) of complementary shape . The diameter of the main grinding wheel will preferably be less than 25 millimeters. This interlocking rib 24 is most often made to present, in cross section, a profile in the form of a dihedral, that is to say in the shape of an inverted V, which is why the interlocking rib 24 is commonly called bevel. Of course, this interlocking rib may have different shapes in cross section, such as for example semicircular or rectangular shapes.

Alternatively and with reference to Figure 4, it can be provided that the machining tool comprises a wheel set comprising, in addition to the aforementioned main wheel 33, an auxiliary beveling wheel 35 provided with a beveling groove 36 depth and / or width less than the depth and / or width of the beveling groove 34 of the main grinding wheel 33. This small beveling groove 36 may for example have a depth and a width 0.3 mm below the depth and width of the bevelling groove 34 of the main wheel 33.

In another variant, as shown in FIG. 5, it may be provided that the machining tool 32 comprises a grinder 37 having a cylindrical central portion 40 of revolution about the axis of rotation A4, and, on the other hand, other of this central portion 40, two end portions 38, 39 conical of revolution about the axis of rotation A4 and arranged back-to-back. These two end portions 38, 39 will then be able to successively machine the two sides of the engagement rib 24 of the ophthalmic lens 20. Of course, it will also be possible for these two end portions to be arranged facing each other. at a distance from each other.

The machining tool may be of another type. It may in particular be formed by a cutter or a knife rotatably mounted about the axis of rotation A4. Knife means a tool having, in the manner of a flat wick, a central shaft on each side of which radially extend, in the same plane, two blades whose opposite free edges are able to machine the blade. slice of the ophthalmic lens.

Preparation process

The process for preparing the ophthalmic lens is carried out in four main steps. It comprises in particular a step of acquiring the shape of a longitudinal profile 12 of the bezel 13 (called the acquired longitudinal profile), a deduction step, depending on the shape of this acquired longitudinal profile 12, of the shape of the a longitudinal profile 25 of the interlocking rib 24 (called the longitudinal profile deduced), a step of determination on this longitudinal profile deduced from singular portions Z1-Z56, and a step of trimming the ophthalmic lens 20 in a particular manner in the singular portions Z1-Z56.

During a first step of acquiring the shape of an acquired longitudinal profile 12 of the bezel 13, the spectacle frame 10 chosen by the future carrier is engaged in the reading apparatus 1 (FIG. 1). For this, the frame 10 is inserted between the pads 4 of the jaws 3, so that one of its entourages 11 is ready to be probed in a path starting by the insertion of the probe 8 between the two studs 4 enclosing the lower part of this entourage, then following the outline of the bezel 13 of this entourage 11.

More precisely, the electronic and / or computer device 9 defines as zero the angular position and the altitude of the probe 8 when the feeler finger 8B is disposed between the two aforementioned studs 4. Once the spectacle frame 10 is fixed and the probe 8 in contact with the bezel 13, the electronic and / or computer device 9 controls the rotation of the turntable 6 so that the feeler finger 8B of the probe 8 moves continuously along the bottom of the bezel 13. The preservation of the contact of the feeler finger 8B with the bottom of the bezel 13 is provided by the actuating means which exert on the probe 8 a radial return force directed towards the bezel 13. This radial return force and thus prevents the feeler finger 8B goes up along one or the other of the sides of the bezel 13 and it does not come out of it. Consequently, the feeler 8 is controlled in angular position around the axis of rotation B and is guided according to its radial coordinate and according to its altitude thanks to the shape here V of the bezel 13.

The electronic and / or computer device 9 raises during the rotation of the turntable 6 the spatial coordinates rai, tetaai, zai of a plurality of points of the acquired longitudinal profile 12 of the bezel 13, for example 360 points, to memorize a precise digital image of this profile. This image, in orthogonal projection in the plane of the initial contour 27 of the ophthalmic lens 20, is shown in dotted line in FIG.

Given the position of the frame 10 in the reading apparatus 1, whose two surrounds 11 extend along the transfer axis D1, the electronic and / or computer device 9 can acquire an orientation parameter of this profile. acquired longitudinal 12 with respect to the A2 skyline around the central axis A1. Here, orientation parameter comprises the coordinates ra _9i tetaa _9i za _9i and ra ₂ 7i, 7i tetaa _2, ₂₇ i za two points of the acquired longitudinal profile 12 (the straight line passing through these two points is indeed parallel to the horizon line).

As a variant, the electronic and / or computer device 9 can acquire the orientation parameter of this acquired longitudinal profile 12 with reference, not to the horizon line, but rather to the line of verticality A3. According to this variant, the orientation parameter may comprise the coordinates rai, tetaai, zai and rai ₃ i, tetaaiβi, za ₁₈ i of two of the points of this acquired longitudinal profile 12 (the line passing through these two points is in fact parallel at the line of verticality).

To acquire the spatial coordinates of the 360 points of the acquired longitudinal profile 12, one can alternatively use a database register. In this variant, the database register comprises a plurality of records each associated with a referenced type of spectacle frames (that is to say, a shape or model of a spectacle frame). More specifically, each record includes an identifier that corresponds to the referenced type of eyeglass frames, and an array of values referencing the spatial coordinates of 360 characteristic points of the shape of the longitudinal profiles of the eyeglass frame bezels of the referenced type (the value of the parameter orientation is in particular deductible from these coordinates). Thus, in this variant, in order to acquire the spatial coordinates ra ,, tetaa ,, za ,, points of the acquired longitudinal profile 12, the operator searches the database for the record whose identifier corresponds to the spectacle frame. selected by the wearer (for example by means of the barcode of the frame). Then, the values referenced in this record are then read and transmitted to the electronic and / or computer device of the trimming apparatus 30.

A disadvantage generally found when using this acquisition method is that, since two frames of the same type rarely have exactly the same shape, the spatial coordinates acquired in the database may be slightly different from the actual coordinates of the data. corresponding points of the bezel. However, thanks to the invention and as will be explained below, these slight differences will not induce problems of nesting of the ophthalmic lens 20 in the entourage 11 of the frame 10 selected by the wearer.

In another variant, the acquisition of point coordinates of the acquired longitudinal profile can be performed in a plane, for example on a photo of the wearer. According to this variant, at first a digital photograph of the wearer equipped with his spectacle frame is acquired. Then, in a second step, we note on the acquired photo the shape of the inner contour of each surround of the eyeglass frame, for example by means of an image processing software. We thus deduce the coordinates ra ,, tetaa, of a plurality of points of the acquired longitudinal profile. This picture also shows the position of the horizon line defined as the line passing through the two pupils of the wearer.

During a second step of deducing the shape of an inferred longitudinal profile 25, the shape of the vertex ridge of the interlocking rib 24 is calculated so that this rib can to nest in the bezel 13 previously palpated. This shape will thus make it possible to determine an instruction to trim the ophthalmic lens 20.

This deduction step may be performed by calculation means of the electronic device and / or computer hosted by the contour reading device 1 or those of the trimming apparatus 30, or by those of any other device capable of communicating with one and / or the other of these devices. two devices 1, 30. In this second step, the calculation means determine, as a function of the spatial coordinates ra ,, tetaa ,, za, points of the acquired longitudinal profile 12, the shape of the longitudinal profile deduced 25 (FIG. ), that is to say the shape that will present the top edge of the interlocking rib 24 after trimming. This form will allow the calculating means of the electronic and / or computer device hosted by the trimming apparatus 30 to derive a trimming radius setpoint and an axial trimming setpoint of the ophthalmic lens 20.

The derived longitudinal profile 25 is here defined by 360 points whose spatial coordinates are denoted rs ,, tetas ,, zs ,. The deduced longitudinal profile 25 is deduced from the acquired longitudinal profile 12 in the sense that it is defined to be either merged with it or deviated from it by a constant projection gap in the mean plane. More precisely, the coordinates rsj, tetas ,, ZSj of the 360 points of the longitudinal profile deduced 25 are calculated from the coordinates ra ,, tetaa ,, za, of the 360 points of the acquired longitudinal profile 12 according to the following mathematical law: For i = j and j ranging from 1 to 360, rs _j = ra, + k; tetas, = teta, ZS ₁ = za, + f (tetas,).

This mathematical law therefore has two components rsj, tetas, in the mean plane which are uniform. More precisely, the constant k is computed in a conventional manner according to the architectures of the contour reading apparatus 1 and the contouring apparatus 30, as well as to the shapes of the cross sections of the bezel of the frame and throat environment. This constant k makes it possible in particular to take account of the fact that, once the lens is nested in the surrounding area, the apex of the interlocking rib (corresponding to the longitudinal profile deduced 25) is never in contact with the bottom of the bezel (corresponding to the acquired longitudinal profile 12) but is slightly offset relative to the latter (Figures 8A and 8B).

The function f (tetas,) can be chosen as zero or constant or variable, to take into account a possible difference between the general camber of the lens and the bezel of the frame. The choice of this function makes it possible particular to modify the axial position of the engagement rib 24 on the edge 23 of the ophthalmic lens 20, so that the interlocking rib 24 extends along the front optical face of the lens or rather middle of his slice. The positioning (also called centering) of this longitudinal profile deduced 25 on the ophthalmic lens 20 is conventionally performed as a function of an optical reference system of the ophthalmic lens 20 and the previously acquired orientation parameter. Such positioning is for example disclosed in EP1866694. During a third step, the calculation means proceed to the detection of at least one singular portion Z1-Z12 (FIG. 9) of the longitudinal profile deduced as a function of said orientation parameter.

This detection will subsequently machine the ophthalmic lens 20 such that its nesting rib 24 is ideally in contact with the bezel 13 outside the singular portions (see FIG. 8A) and out of contact with this bezel 13 in these portions. singular (see Figure 8B). It is thus understood that the interlocking rib 24 will be machined in a conventional and uniform manner out of the singular portions of the longitudinal profile 25 deduced, so that the nesting rib 24 fits into the bezel 13, and it will be machined in a particular and non-uniform manner in the singular portions of the longitudinal profile deduced 25, so that ideally the interlocking rib 24 does not fit completely in the bezel 13.

The sections of the interlocking rib 24 in which contact with the bezel 13 are expected to be called bearing sections, while the sections of the interlocking rib 24 in which it is expected that it will not There is no contact with the bezel 13 are called sections of freedom. These sections of freedom are so named because if the lens is not properly cut and has a contour too large compared to that of the entourage 11 corresponding, this entourage is free to deform at these sections of freedom to marry the shape of the nesting rib. In this sense, the singular portions could also be called portions of freedom.

The determination of the positions of the singular portions Z1-Z13 of the derived longitudinal profile can be carried out in various ways.

For example, with reference to FIG. 9, the calculation means may define a polygon 26 inscribed or circumscribed at the first or second longitudinal profile 12, 25; 27 and oriented relative thereto around said central axis A1 according to said orientation parameter, then associating each point of this polygon 26 with a point of the longitudinal profile deduced 25 according to a given correspondence rule, and finally determining each singular portion Z1-Z12 as a portion comprising a singular point P2, P5, P8, P11 whose associated point on said polygon 26 is angular.

As represented in FIG. 9, the polygon corresponds here to the boxing frame 26. A point of the longitudinal profile deduced 25 is then defined as being associated with a point of the boxing frame 26 if these two points comprise the same angular position around the box. central axis A1, that is to say if these two points are located on the same line passing through the geometric center C1 of the boxing frame 26. The calculation means then deduce the positions on the longitudinal profile deduced from four points singular P2, P5, P8, P11, whose associated points on the boxing frame 26 correspond to the four corners of this frame. These four singular points are thus located at the intersections of the longitudinal profile deduced with the diagonals of the boxing frame 26.

Once these four singular points have been defined, the calculation means here further define eight other singular points P1, P3, P4, P6, P7, P9, P11, P12 situated on either side of each of the four singular points P2. P5, P8, P11 previously defined, at a distance dO of these here equal to 5 millimeters in curvilinear abscissa along the longitudinal profile deduced 25.

The calculation means deduce therefrom the positions of twelve singular portions Z1-Z12 of the derived longitudinal profile 25 which correspond to the parts of this profile which are centered on the twelve singular points P1-P12 and which have lengths less than 10 millimeters, here equal at 5 millimeters. It will be noted in FIG. 9 that the singular portions Z1-Z12 of the derived longitudinal profile 25 are situated close to the particularly curved zones of this longitudinal profile deduced 25. The particular machining of the interlocking rib 24 in these singular portions Z1- Z12 will thus give the entourage 11 (out of contact with the engagement rib 24) a free play which will make it possible to catch any machining errors of the ophthalmic lens, as will be explained in more detail later.

As a variant and with reference to FIG. 10, to determine the positions of the singular portions Z14-Z17 of the derived longitudinal profile 25, the calculation means distribute these singular portions on this profile, starting from a starting point determined as a function of said orientation parameter, so that they are evenly spaced around the central axis A1. More particularly, the calculation means select from among the 360 points of the longitudinal profile deduced 25 a starting singular point P15, which is here located at 45 degrees with respect to the horizon line A2 around the central axis A1 (for example the point of index j = 46). They then select as singular points P16, P17, P14 the three points of this deduced longitudinal profile 25 which, with the starting singular point P15, are spaced two by two around the central axis A1 of an equal separation angle E1. at 90 degrees.

The calculation means deduce therefrom the positions of the singular portions Z14-Z17 of the derived longitudinal profile 25 which correspond to the parts of this profile which are centered on the singular points P14-P17 and which have lengths equal to 10 millimeters.

It will be noted that here, too, the singular portions Z14-Z17 of the derived longitudinal profile 25 are located near the particularly curved zones of this longitudinal profile deduced 25. As a variant and with reference to FIG. 11, to determine the positions of the singular portions Z18-Z33 of the longitudinal profile deduced 25, the calculation means can distribute on the longitudinal profile deduced 25 a plurality of singular points P18-P33 in positions which depend on the geometry of a third longitudinal profile 26, whose form is function from that of the longitudinal profile deduced 25.

More precisely, the calculation means can distribute, from a singular starting point whose position is a function of the orientation parameter, a plurality of singular portions Z21-Z31 on the longitudinal profile deduced so that the zones corresponding third longitudinal profile 26 are regularly spaced curvilinear abscissa along the third longitudinal profile 26.

In the variant embodiment shown in FIG. 11, the calculation means select sixteen first singular points P118-P133 regularly spaced along the boxing frame 26 (which forms the third longitudinal profile), of the same length d1, starting from a singular point P118 starting at the vertical of the geometric center C1, below the horizon line A2 (index point j equal to 1). This singular starting point P118 is therefore chosen according to the orientation parameter, so that the line passing through this singular point and the geometric center C1 is parallel to the line of verticality A3. Then, the calculation means establish a rule of correspondence between the points of this boxing frame 26 and the points of the longitudinal profile deduced 25. For this purpose, a point of the profile deduced longitudinal 25 is defined as being associated with a point of the boxing frame 26 if these two points comprise the same angular position around the central axis A1, that is to say if these two points are located on the same straight line by the geometric center C1 of the boxing frame 26. The calculation means then deduce the positions on the longitudinal profile deduced from sixteen second singular points P18-P33 associated with the first sixteen singular points P118-P 133 of the boxing frame 26. Finally, the calculation means define as singular portions Z18-Z33 of the longitudinal profile deduced 25 the sixteen parts of this profile which are centered around these second singular points P18-P33 and which have predetermined lengths, for example equal to 6 millimeters.

Given the large number of singular portions (here equal to sixteen and at least ten), we observe that a portion of these singular portions are located near the particularly curved areas of the longitudinal profile deduced 25. In a variant and in reference in FIG. 12, to determine the positions of the singular portions Z34-Z38 of the derived longitudinal profile 25, the calculation means can position a predetermined number of singularly spaced singular portions along the abscissa along the longitudinal profile deduced 25, starting from a starting point determined according to said orientation parameter.

More precisely, the calculation means select from among the 360 points of the longitudinal profile deduced a starting singular point P34, which is here located vertically from the geometric center C1, below the horizon line (the index point j = 1). They then select as singular points P34-P38 the points of this profile which are spaced from each other in curvilinear abscissa of the same distance d2, for example equal to one thirtieth of the total length of the longitudinal profile deduced 25.

The calculation means then deduce the positions of the thirty singular portions Z34-Z38 of the derived longitudinal profile 25 which correspond to the parts of this profile which are centered on the thirty singular points P34-P38 and which have lengths for example equal to one-sixtieth of the total length of the longitudinal profile deduced 25.

Note that here too, given the large number of singular portions, a portion of these singular portions are located near the particularly curved areas of the longitudinal profile deduced 25.

Alternatively and with reference to FIG. 13, to determine the positions Z39-Z47 singular portions of the longitudinal profile deduced 25, the calculation means define a polygon 28 inscribed in the longitudinal profile deduced 25 or in the acquired longitudinal profile 27 and oriented relative thereto about said axis of orientation A1 in according to said orientation parameter, then they determine each singular portion Z39-Z47 as a portion having a point belonging to said polygon 28.

More specifically, the calculation means select from among the 360 points of the longitudinal profile deduced 25 a starting point P39, which is here located vertically from the geometric center C1, below the horizon line (the index point j equal to 1). They then calculate from this singular starting point P39 the position of the vertices of a polygon 28 which is inscribed in the longitudinal profile deduced 25, whose side number is at least eight (here equal to nine) and whose the sides have identical lengths. They then select as singular points P39-P47 of the longitudinal profile deduced 25 points of this profile which are located at the vertices of this polygon.

The calculation means then deduce the positions of the singular portions Z39-Z47 of the derived longitudinal profile 25 which correspond to the parts of this profile which are centered on the singular points P39-P47 and which have lengths for example equal to 5 millimeters. Given the large number of sides of this polygon, it is observed that a portion of the singular portions are located near the particularly curved areas of the longitudinal profile deduced 25.

As a variant and with reference to FIG. 14, in order to determine the positions of the singular portions Z48-Z51 of the derived longitudinal profile 25, the calculation means define a polygon 26 circumscribing the longitudinal profile deduced 25 or the acquired longitudinal profile 27 and oriented relative to each other. thereto about said A1 orientation axis according to said orientation parameter, then they determine each singular portion Z48-Z51 as a portion having a point belonging to said polygon 26. More specifically, the calculation means determine on the longitudinal profile deduced the positions of the four singular points P48-P51 which also belong to the boxing frame 26.

The calculation means then deduce the positions of four singular portions Z48-Z51 of the derived longitudinal profile 25 which correspond to the parts of this profile which are centered on the singular points P48-P51 and which have lengths for example equal to 5 millimeters. Note that the singular portions Z48-Z51 of the longitudinal profile deduced 25 are located near the particularly curved areas of this longitudinal profile deduced 25.

As a variant and with reference to FIG. 16, to determine the positions of the singular portions Z53-Z56 of the derived longitudinal profile 25, the calculation means determine the position of an inclined frame 29 which is circumscribed to the longitudinal profile deduced 25 and whose four sides are oriented at 45 degrees to the horizon line. Then, they determine on the longitudinal profile deduced 25 the positions of the four singular points P53-P56 of this profile which also belong to the inclined frame 29.

The calculation means then deduce the positions of the singular portions Z53-Z56 of the derived longitudinal profile 25 which correspond to the parts of this profile which are centered on the singular points P53-P56 and which have lengths for example equal to 5 millimeters. It will be noted that here too, the singular portions Z53-Z56 of the longitudinal profile deduced 25 are located near the particularly curved zones of this longitudinal profile deduced 25.

As a variant and with reference to FIG. 15, to determine the position of a singular portion Z52 of the derived longitudinal profile 25, the calculation means acquire the coordinates of the point of intersection P102 of two tangents T1, T2 with the longitudinal profile deduced 25 at two points P100, P101 positioned on this profile as a function of said orientation parameter, then they determine said singular portion Z52 as a portion comprising the point of the second longitudinal profile 25 which is closest to said intersection point P102 or which has an orientation about said central axis A1 identical to that of said intersection point P102.

More particularly here, the calculation means firstly select the two points P100, P101 of the longitudinal profile 25 located in the temporal portion of this profile, above the horizon line and oriented with respect thereto around of the central axis A1 of 30 and 60 degrees (index points j equal to 121 and 151). Then, in a second step, the calculation means determine the positions of the tangents T1, T2 to the longitudinal profile deduced at these two points P100, P101 and they deduce the angular position around the central axis A1 of the intersection point. P102 of these two tangents T1, T2. Finally, in a third step, the calculation means define as singular point P52 of the longitudinal profile deduced 25 the point having a position angular identical to that of the point of intersection P102.

The calculation means then deduce the position of the singular portion Z52 of the derived longitudinal profile 25 which corresponds to the portion of this profile which is centered on the singular point P52 and which has a length for example equal to 10 millimeters.

According to another variant not shown, to determine the positions of singular portions of the longitudinal profile deduced 25, the calculation means read the record of the database register which contains here, in addition to the coordinates of points representative of the shape of the longitudinal profile. acquired 27, the coordinates of points representative of the shape of the longitudinal profile deduced 25 as well as the positions of each singular portion on this longitudinal profile deduced 25.

Finally, during a fourth and last step, the trimming apparatus 30 trims the ophthalmic lens 20. This step will be described here with reference to FIG. 9.

According to a first embodiment of the invention, the support shafts 31 of the lens and / or the trimming tool 32 are driven according to a clipping radius setpoint which differs from the initially planned trimming radius setpoint (according to the longitudinal profile deduced 25) in the singular portions Z1-Z12.

For this purpose, the calculation means correct the shape of the longitudinal profile deduced in these singular portions Z1-Z12.

To obtain the coordinates of 360 characteristic points of this new longitudinal profile deduced 27, the calculation means reduce the values of the radial coordinates rsj points of the initial deduced longitudinal profile located in the singular portions Z1-Z12. This reduction is made in such a way that the new longitudinal profile deduced 27 is continuous, that it has neither angular points nor cusp points, and that it deviates in each singular portion Z1-Z12 by more than 0.05 millimeter and less than 0.3 millimeter of the initial longitudinal profile deducted. The reduction is here made such that the maximum deviation between the new longitudinal profile deduced 27 and the initial derived longitudinal profile is equal to 0.1 millimeter.

By angular point is meant a point of a profile to which the two half-tangents form a non-flat angle. By curb point is also meant a point of a profile to which the two half-tangents are opposite. In summary, the aforementioned mathematical law making it possible to determine the coordinates of the points of the initial longitudinal profile deduced according to those of the points of the acquired longitudinal profile 12 is corrected in the singular portions in order to obtain the coordinates of the points of the new longitudinal profile deduced 27. This mathematical law is therefore different for the portions. singular Z1-Z12 and for the remainder of the new longitudinal profile 27, so that the average radius of curvature of each singular portion Z1-Z12 of the new profile 27 is increased relative to the average radius of curvature of the initial profile 25 in this singular portion Z1-Z12.

Finally, the lens is cut off in a conventional manner, by means of the main grinding wheel 33 of the trimming apparatus 30, such that the apex of the interlocking rib 24 (FIG. 7A) extends according to the new longitudinal profile. deducted 27. The nesting rib 24 is then profiled, that is to say that it has a uniform section over its entire length.

Finally, if we consider the visual equipment comprising the eyeglass frame 10 and the ophthalmic lens 20 fitted into the corresponding surrounding 11 of this frame, it is observed that the engagement rib 24 of the lens has, on the one hand , sections (Figure 8A), located outside the singular portions, at which it is in contact with the bezel 13, alternated with, on the other hand, sections (Figure 8B), located in the singular portions, at which it is out of contact with the bezel.

Therefore, when the probing of the bezel and / or the clipping of the lens are imperfectly made and that, therefore, the contour of the lens is slightly too large compared to that of the entourage 11, the space located at the level of singular portions allows the entourage to deform, so that the lens remains mountable in the entourage.

Advantageously, it will be possible, after the determination step, to store the shape of the new longitudinal profile deduced 27 in a database register. For this purpose, the register may comprise a plurality of records each of which is associated with a type or model of glasses frames referenced and contains the shape of a new longitudinal profile deduced 27 common to the frames of this type or this model. The storage in the register of the shape of the new longitudinal profile deduced 27 will then be performed by searching in this register a record corresponding to the mount concerned and by writing in this record the shape of the new longitudinal profile deduced 27. In this way, when subsequently trimming an ophthalmic lens for mounting in a mount of the same type or the same model, the calculating means can acquire in the register the shape of this new longitudinal profile deduced 27, so as to directly machine the lens according to this profile.

According to a second embodiment of the invention, the support shafts 31 of the lens and / or the trimming tool 32 are controlled so that the section of the interlocking rib 24 is locally narrowed in width and / or in height (Figure 7B) in the singular portions Z1-Z12.

More specifically, the support shafts 31 of the lens and / or the trimming tool 32 are controlled according to the first longitudinal profile 25, so as to produce on the edge 23 of the lens 20 a profiled engagement rib 24, that is to say of uniform section, except in the singular portions Z1-Z12.

This embodiment has a particular advantage. Indeed, the fact of only decreasing the size of the section of the interlocking rib 24 without modifying the instruction of clipping radius makes it possible to ensure that the distance between the foot of the nesting rib 24 (part of the edge 23 of the lens bordering the interlocking rib 24) and the inner face of the surrounding 11 of the spectacle frame 10 is uniform all around the lens. As a result, no unsightly gap appears between the edge of the lens and the inner face of the surround 11. Preferably, the contouring of the ophthalmic lens 20 comprises a first machining step of the interlocking rib 24 with a uniform section and a second phase of trimming of the interlocking rib 24 in each singular portion Z1-Z12.

Here, the first machining phase is carried out by means of the main grinding wheel 33 of shape (represented in FIG. 3) according to the longitudinal profile deduced 25, while the second phase is produced by means of the auxiliary grinding wheel 35 ( shown in Figure 4).

During this second phase, the bevelling groove 36 of the auxiliary beveling wheel 35 is brought into contact with the engagement rib 24, at one end of a first singular portion. Then the support shafts 31 of the lens and / or the trimming tool 32 are controlled so that the beveling groove 36 can machine and reduce the height and width of the interlocking rib 24 in this singular portion. This control is carried out so that the height and the width of the engagement rib 24 are reduced by at most 0.3 millimeters and that the engagement rib 24 does not have any discontinuity, in particular at the ends of each singular portion Z1-Z12.

Finally, considering the visual equipment formed by the ophthalmic lens 20 cut away, it is observed that its interlocking rib 24 has a narrowed section in width and / or height in the singular portions Z1-Z12. It is further observed that this narrowing width and / or height of the interlocking rib 24 is between 0.05 and 0.3 millimeter.

Moreover, it can be seen that, if the section of the interlocking rib 24 has been narrowed in height, the longitudinal profile deduced 25 along which this nesting rib 24 extends is slightly deformed at said singular portions.

This mode of contouring of the ophthalmic lens 20 is not limiting. The trimming of the interlocking rib 24 may in particular be made in a different manner.

For example, it may be realized during a second pass of the main grinding wheel 33, moving it in a direction substantially parallel to the central axis A1 locking the lens, transversely offset from the longitudinal profile Deduced 25. More precisely, during this second pass, the support shafts 31 of the lens and / or the trimming tool 32 can be controlled in each singular portion Z1-Z12 so as to shift progressively axially (according to the invention). central axis A1) relative to the position they had during the first pass of the main grinding wheel 33. Thus, during this second pass, one of the flanks of the interlocking rib 24 is machined by one flanks of the beveling groove 34 of the main grinding wheel 33, which has the effect of reducing the height and the width of the interlocking rib 24.

In another example, the trimming of the interlocking rib 24 can be achieved using a cylindrical portion of the main grinding wheel 33, by planing the top of the interlocking rib 24, so as to break its edge. top, or even locally remove the interlocking rib 24. In this embodiment, only the height of the interlocking rib 24 is modified.

In another alternative embodiment of the trimming of the ophthalmic lens 20, the roughing and trimming of the interlocking rib 24 may be simultaneously performed.

More particularly, during the beveling of the lens by the main grinding wheel 33, the support shafts 31 of the lens and / or the trimming tool 32 may be controlled so as to present axial reciprocating movements. (along the central axis A1). Thus, these reciprocating movements will plan the two flanks of the interlocking rib 24.

As a variant, the grinder shown in FIG. 5 can also be used to machine the engagement rib 24 in two successive phases, including a machining phase of a first of its flanks and a machining phase of a second of its flanks.

For this purpose, in a first step, the electronic and / or computer device of the trimming apparatus 30 will control the radial mobility of the grinder and / or shafts 31 to position a first conical end portion 39 of the grinder 37 against the side 23 of the lens, the side of its front face. Then, the grinder 37 and the support shafts 31 of the lens will be controlled to form the front flank of the engagement rib 24. Here, this steering will be realized so that the leading edge of the nesting rib 24 is located at a constant distance from the optical front face of the lens 20, except in the singular portions where it will deviate from this face.

In a second step, the electronic and / or computer device of the trimming apparatus 30 will control the radial mobility of the grinder and / or the shafts 31 to position a second conical end portion 38 of the grinder 37 against the slice. the lens, on the side of its back side. Then, the grinder 37 and the support shafts 31 of the lens will be driven to form the trailing edge of the engagement rib 24. Here, this steering will be realized so that the trailing edge of the interlocking rib is located at a constant distance from the front face of the lens, except in the singular portions where it will approach the front face. The nesting rib of the ophthalmic lens will thus present a local narrowing of height and / or width in each singular portion.

According to another variant, the electronic and / or computer device of the trimming apparatus 30 may control the radial mobility of the machining tool and / or the shafts 31 so as not only to reduce in width and / or height the section of the interlocking rib 24 on each singular portion but also to machine the feet of the interlocking rib 24 (by determining the shape of a new longitudinal profile from the longitudinal profile deduced, according to a method of the type of the one mentioned above).

Advantageously, it will be possible to record the shape of the longitudinal profile deduced in a record of the database register, as well as the positions of the singular points on this profile. For that, the The register may have a plurality of records, each of which is associated with a referenced type or model of eyeglass frames and contains the shape of an inferred longitudinal profile common to frames of this type or model. The memorization of the shape of the longitudinal profile deduced 25 will then be achieved by searching in this register a record corresponding to the mount concerned and by writing in this record the shape of the longitudinal profile deduced 25. In this way, when trimming a lens ophthalmic for mounting in a frame of the same model or the same type, the calculating means can acquire in the database the shape of this longitudinal profile deduced 25, so as to directly machine the lens according to this profile and to the trim to singular points.

Following the shaping of this ophthalmic lens, it will be possible to trim a second ophthalmic lens for mounting in a second surround of said spectacle frame 10, forming on its edge a generally profiled nesting rib. This rib will then be made so that it follows a symmetrical longitudinal profile of the longitudinal profile 25; 27 and such that each of its sections has a shape identical to that of the corresponding section (by symmetry) of the interlocking rib 24 of the first lens. Thanks to the invention, if the two surrounds of the eyeglass frame 10 are not perfectly symmetrical while the two lenses have been machined in a symmetrical manner, the spaces between the interlocking ribs of the lenses and the bezels of the surrounds at The level of the singular portions allow the two lenses to be mountable in their surroundings. The present invention is not limited to the embodiment described and shown, but the art can apply any variant within his mind.

This invention will find particularly advantageous application when implemented by customers (opticians) called "outsourcers" subcontracting the manufacture and trimming of lenses.

More specifically, consider here, on the one hand, a customer-side terminal installed on a customer's side for the control of lenses, and, on the other hand, a manufacturer-terminal installed on the side of a lens manufacturer for manufacture and trimming of lenses. The client terminal comprises computer means for recording and transmitting control data of the ophthalmic lens 20, for example via an IP communication protocol (Internet type). This control data includes visual correction prescription data (eg optical power, centering data, etc.) and mount data. The terminal-manufacturer comprises meanwhile IT means for receiving and recording the order data transmitted by the client terminal. It further comprises a device for manufacturing the ophthalmic lens in accordance with the prescription data, comprising, for example, means for molding the lens and / or for machining at least one of the optical faces of the lens. It also includes a device for trimming this ophthalmic lens in accordance with the data relating to the frame. This clipping device is in particular designed to implement the fourth step of the method described above.

The implementation of this method for preparing lenses is here also carried out in four steps.

During the first step, the client determines a reference of the eyeglass frame 10 and then transmits via the terminal-client control data of a lens (the data comprising said reference).

The second step is performed by means of a database register equipping the manufacturer terminal, each record of which is associated with a type of spectacle frames 10 and contains, firstly, a reference of this type of frames. , secondly, the shape of an acquired longitudinal profile 12 common to the surrounding 11 of this type of frames, and, thirdly, an orientation parameter associated with this profile. During this second step, the manufacturer searches in this database register for the shape and the orientation parameter of the acquired longitudinal profile 12 of the spectacle frame selected by the wearer (using the reference determined at the first stage). He then deduces from the shape of this acquired longitudinal profile 12 the shape of the longitudinal profile deduced by a method of the type of that previously stated.

Finally, during the third and fourth steps, the manufacturer determines on this longitudinal profile deduced 25, according to said orientation parameter, at least one singular portion and then it diverts the lens specifically in each singular portion. As before, the lens will be easily mountable "first time" in the frame selected by the wearer. As a result, the lens not be returned to the manufacturer for resumption, which is always long and expensive.

In a variant, provision may be made for the acquisition step of the acquired longitudinal profile 12 to comprise two steps, including a first step of determining by the customer the shape of the acquired longitudinal profile 12 and the associated orientation parameter, for example by probing the surroundings of the eyeglass frame, and a second step of transmitting / receiving control data comprising the shape of the acquired longitudinal profile 12 and the orientation parameter. In this variant, the determination of the positions of the singular portions on the acquired longitudinal profile 12 may indifferently be carried out by the manufacturer or by the customer.

Claims

1. A method for preparing an ophthalmic lens (20) for mounting in an environment (11) of an eyeglass frame (10), comprising: - a step of acquiring a first longitudinal profile (12); ) of said surround (11) and an orientation parameter of said first longitudinal profile (12) relative to a horizon line (A2) or vertical line (A3) of said surround (11) about an axis of orientation (A1) substantially perpendicular to a mean plane of said surround (11), - a step of trimming the ophthalmic lens (20) with formation on its edge (23) of a generally profiled interlocking rib (24) having a desired section and extending along a second longitudinal profile (25) which is derived from the first longitudinal profile (12) and whose orientation relative to the ophthalmic lens (20) about said orientation axis (A1) is deduced from said parameter orientation, characterized in that it comprises a step of determining at least one singular portion (Z1-Z56) of the second longitudinal profile (25) as a function of said orientation parameter, and in that during the clipping step, the nesting rib (24) is formed to have a narrowed section in width and / or height on said singular portion (Z1-Z56).

2. Method according to the preceding claim, wherein the width and / or height of the interlocking rib (24) is narrowed by at least 0.05 millimeters in at least one section of each singular portion (Z1-Z56) . 3. Method according to one of the preceding claims, wherein the width and height of the interlocking rib (24) are narrowed by at most 0,

3 millimeters in each singular portion (Z1-Z56).

4. A method for preparing an ophthalmic lens (20) for mounting in an environment (11) of an eyeglass frame (10), comprising: - a step of acquiring a first longitudinal profile (12); ) of said surround (11) and an orientation parameter of said first longitudinal profile (12) relative to a horizon line (A2) or vertical line (A3) of said surround (11) about an axis of orientation (A1) substantially perpendicular to a mean plane of said surround (11), - a step of trimming the ophthalmic lens (20) with forming on its edge (23) a generally profiled interlocking rib (24) having a desired section and extending along a second longitudinal profile (27) which is derived from the first longitudinal profile (12) and whose orientation relative to the ophthalmic lens (20) about said orientation axis (A1) is deduced from said orientation parameter, characterized in that it comprises a step of determining at least one singular portion (Z1-Z56) of the second longitudinal profile (27) as a function of said orientation parameter, and that during from the trimming step, the interlocking rib (24) is formed so that the second longitudinal profile (27) is deductible from the first longitudinal profile (12) by a mathematical law which is different on said singular portion (Z1-Z56 ) for the remainder of the second longitudinal profile (27), so that the average radius of curvature of this singular portion (Z1-Z56) of the second longitudinal profile (27) is increased with respect to the average radius of curvature that this singular portion (Z1-Z56) would have presented if the mathematical law had been, on this singular portion (Z1-Z56), the same as for the remainder of the second longitudinal profile (27).

5. Method according to the preceding claim, wherein said singular portion (Z1-Z56) of the second longitudinal profile (27) has, with respect to the shape that this singular portion (Z1-Z56) would have presented if the mathematical law had been, on this singular portion (Z1-Z56), the same as for the remainder of the second longitudinal profile (27), a difference in at least one point greater than 0.05 millimeter.

6. Method according to one of the two preceding claims, wherein the singular portion (Z1-Z56) of the second longitudinal profile (27) has, with respect to the shape that this singular portion (Z1-Z56) would have presented if the law In this singular portion (Z1-Z56), the mathematics had been the same as for the remainder of the second longitudinal profile (27), a deviation in all points of less than 0.3 millimeters.

7. Method according to one of the three preceding claims, wherein during the trimming step, the interlocking rib (24) is formed to have a section of uniform geometry along the second longitudinal profile (27). .

8. Method according to one of the preceding claims, wherein during the step of trimming, the interlocking rib (24) is formed to have a continuous profile without angular point or cusp.

9. Method according to one of the preceding claims, wherein each singular portion (Z1-Z56) has a length of less than 10 millimeters.

10. Method according to one of claims 1 to 9, wherein, to determine each singular portion (Z1-Z56), defines a polygon (26; 28) inscribed or circumscribed to the first or second longitudinal profile (12, 25). 27) and oriented relative thereto about said orientation axis (A1) as a function of said orientation parameter, each point of which is associated with a point of the second longitudinal profile (25; 27) according to a correspondence rule given, then each singular portion (Z1-Z56) is determined as a portion having a point whose associated point on said polygon (26; 28) is angular.

11. Method according to one of claims 1 to 9, wherein, to determine each singular portion (Z1-Z56), defines a polygon (26; 28; 29) circumscribing the first or second longitudinal profile (12, 25). 27) and oriented with respect thereto about said orientation axis (A1) as a function of said orientation parameter, then each singular portion (Z1-Z56) is determined as a portion having a point belonging to said polygon ( 26; 28; 29).

12. Method according to one of claims 1 to 9, wherein, in the determining step, is positioned a predetermined number of singular portions (Z1-Z56) regularly spaced curvilinear abscissa along the second longitudinal profile (25; 27) from a starting point determined according to said orientation parameter.

13. Method according to one of claims 1 to 9, wherein, in the determining step, is positioned a predetermined number of singular portions (Z1-Z56) regularly spaced about an axis of the lens passing to the interior of the second longitudinal profile (25; 27) from a starting point determined according to said orientation parameter.

14. Method according to one of claims 1 to 9, wherein, in the determining step, one acquires the point of intersection (P102) of two tangents (T1, T2) to the second longitudinal profile (25; 27). at two points (P100, P101) positioned on said second longitudinal profile (25; 27) as a function of said orientation parameter, and then determining said singular portion (Z1-Z56) as a portion having the point of the second longitudinal profile ( 25; 27) which is closest to said point of intersection (P 102) or which has an orientation about said axis of orientation (A1) identical to that of said point of intersection (P102).

15. Method according to one of claims 1 to 9, wherein after the determining step, searching, in a database register whose registration is associated with a type of spectacle frames (10) referenced and containing the shape of the second longitudinal profile (25; 27), a record corresponding to the mount concerned and one writes in this record the positions of each singular portion (Z1-Z56) on the second longitudinal profile (25; 27).

16. Method according to one of the preceding claims, wherein during the acquisition step, a record of a database register is recorded, each record of which is associated with a type of spectacle frames (10). referenced and contains, on the one hand, the shape of the first acquired longitudinal profile (12) of the bezel (13) corresponding to the type of glasses frames referenced, and, on the other hand, said orientation parameter.

17. Method according to one of the preceding claims, comprising a step of shaping a second ophthalmic lens for mounting in a second surround of said spectacle frame (10), forming on its edge an interlocking rib generally profiled which extends along a given symmetrical longitudinal profile of said second longitudinal profile (25; 27) and each section of which has a width and / or height identical to the width and / or height of the corresponding section, by symmetry of the interlocking rib (24) of said first ophthalmic lens (20).

18. The method as claimed in one of the preceding claims, implemented by means of a system comprising, on the one hand, a client terminal installed on the client side and comprising computer means for recording and transmitting data from ophthalmic lens control (20), which control data includes eyeglass frame data (10), and a manufacturer-installed terminal-manufacturer with computer means for receiving and recording the control data transmitted by the client terminal, and a clipping device of this ophthalmic lens manufactured designed to implement said clipping step, said acquisition step comprising:

a step of determining, by the customer, the first longitudinal profile (12) of the surrounding (11) of the spectacle frame (10) and of said orientation parameter, and

a step of transmission by the terminal-client and reception by the terminal-manufacturer of the control data, these data integrating said first longitudinal profile (12) and said orientation parameter.

19. Method according to one of claims 1 to 17, implemented by means of a system comprising, on the one hand, a customer-side terminal installed on the client side and comprising computer means for recording and transmitting data. control data of the ophthalmic lens (20), which control data includes eyeglass frame data (10), and a manufacturer-installed manufacturer's terminal having means computer system for receiving and recording the control data transmitted by the client terminal and a device for trimming the ophthalmic lens manufactured to perform said clipping step, said acquisition step comprising:

a step of determining, by the customer, a reference of the spectacle frame (10),

a step of transmission by the terminal-client and reception by the terminal-manufacturer of the control data, these data integrating said reference, and

a step of searching by the manufacturer-terminal, in a database register, each record of which is associated with a type of spectacle frames (10) and containing a reference of this frame, the first longitudinal profile (12) of the surround (11) of this frame, and said orientation parameter, a record associated with the frame reference concerned.