EP1606078A1 - Method for trimming a spectacle lens - Google Patents

Method for trimming a spectacle lens

Info

Publication number
EP1606078A1
EP1606078A1 EP04742330A EP04742330A EP1606078A1 EP 1606078 A1 EP1606078 A1 EP 1606078A1 EP 04742330 A EP04742330 A EP 04742330A EP 04742330 A EP04742330 A EP 04742330A EP 1606078 A1 EP1606078 A1 EP 1606078A1
Authority
EP
European Patent Office
Prior art keywords
lens
face
points
coordinates
meridian
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP04742330A
Other languages
German (de)
French (fr)
Other versions
EP1606078B1 (en
Inventor
Laurent Guillermin
Ludovic Jouard
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EssilorLuxottica SA
Original Assignee
Essilor International Compagnie Generale dOptique SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Essilor International Compagnie Generale dOptique SA filed Critical Essilor International Compagnie Generale dOptique SA
Publication of EP1606078A1 publication Critical patent/EP1606078A1/en
Application granted granted Critical
Publication of EP1606078B1 publication Critical patent/EP1606078B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B9/00—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor
    • B24B9/02—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground
    • B24B9/06—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain
    • B24B9/08—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass
    • B24B9/14—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass of optical work, e.g. lenses, prisms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B47/00—Drives or gearings; Equipment therefor
    • B24B47/22—Equipment for exact control of the position of the grinding tool or work at the start of the grinding operation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B41/00—Component parts such as frames, beds, carriages, headstocks
    • B24B41/06—Work supports, e.g. adjustable steadies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B9/00—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor
    • B24B9/02—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground
    • B24B9/06—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain
    • B24B9/08—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass
    • B24B9/14—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass of optical work, e.g. lenses, prisms
    • B24B9/148—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of glass of optical work, e.g. lenses, prisms electrically, e.g. numerically, controlled

Definitions

  • the present invention relates to the machining of an outline of spectacle lens to adapt it to the frame circle which is to receive it.
  • a spectacle lens called a lens, whether or not it is corrective, comes from a part which has all the optical qualities required for its use and in particular an optical center which will be called center of the lens. This part is most often of circular outline, of a sufficient diameter so that one can register there all the possible forms of periphery corresponding to the immense variety of the circles or entourages of frames existing on the market.
  • Trimming is the machining operation which consists in making the contour of the lens adapted to the shape of the frame which receives it.
  • This peripheral machining implements a tool in which the lens is clamped in the vicinity of its center between two holding accessories and in general driving in rotation of the lens around an axis which passes through it, while a grinding wheel realizes generally in two phases, the desired contour.
  • the lens clamping accessories are in the form of pads which, pressed against the two concave and convex faces of the lens, generate stresses and deformations of the latter. The machining of the contour is therefore carried out on a lens deformed under stress which, in the relaxed state, will affect a different shape therefore a different contour from that machined.
  • the invention therefore relates to a method for carrying out the precise trimming of a lens in order to allow its mounting in a determined frame circle, according to which the lens is held between two clamping pads, in a defined and known position in a reference frame linked to the pads and the grinding of the periphery of the lens is controlled along a trajectory whose programmed end part corresponds on the lens to the shape of the frame circle.
  • the method comprises:
  • the statement of the coordinates of the points of the deformed face will be carried out after a rough outline has been produced.
  • the deformation of the lens under the effect of tightening, varies with the amount of material involved and in particular with the dimension along the radius of this lens.
  • there are different deformations of the lens depending on whether the periphery of the latter is near or far from the center.
  • the mathematical representation of the shape of the face of the lens is carried out by the mathematical approximation of the shape of at least one meridian arc of this lens, that is to say say the line of the surface (for example convex) of the lens which runs between the center of this one and any point of this surface (one could say the orthodromic arc between the center and the point considered) and in particular a point of the programmed contour of the frame circle in the undeformed state of the lens.
  • the first reading comprises the probing of the points of the above-mentioned face of the lens belonging to at least one meridian arc, in an area close to the above-mentioned trace, in order to determine a mathematical approximation of the shape of this meridian arc
  • the second reading concerns points of this meridian arc already palpated in order to determine a mathematical approximation of the shape of this arc, correlated to the first approximation
  • the calculation and the correction aforementioned consist in calculating the value of the coordinates of the point of the meridian arc belonging to the programmed contour of the circle of ture in the mathematical representation of the meridian arc under deforming stress and to correct the terminal part of the trajectory of the grinding wheel by a coefficient drawn from the difference between the programmed coordinates and the calculated coordinates of this point of intersection.
  • the programmed contour of the mounting circle actually corresponds to a cylindrical envelope whose generatrices, parallel to the axis of tightening of the lens, build on this outline.
  • generatrices parallel to the axis of tightening of the lens, build on this outline.
  • a clipping of the glass requires the creation of a relief on the edge of the lens (either in the hollow for the passage of a strapping link or in a bump to enter the bezel of the frame circle).
  • This relief is produced by the shape of the edge of the grinding wheel which must therefore be controlled in position along the above-mentioned direction in order to keep it always opposite the edge of the lens. To allow this piloting and this in a precise way, it is therefore advisable to ver the coordinates of the points of the projection of the contour programmed on the lens and in particular the coordinate along the tightening axis of each of these points.
  • This reading can be carried out under one or the other of the tightening conditions of the lens and by a calculation carried out from this reading and mathematical representations of the probing surface of the lens, the parameters of this piloting in position along the tightening direction to take account of the deformation of the lens during its trimming. These parameters are in addition to those which, as said previously, determined the final trajectory of the grinding wheel in the control of the machine.
  • FIG. 1 is a diagram illustrating a device for trimming a spectacle lens
  • FIG. 2 is a diagram illustrating the different phases of the method according to the invention. DETAILED DESCRIPTION OF THE INVENTION
  • a substantially circular lens 1 is clamped between two pads 2 and 3 so that it can be rotated about an axis 4 which passes through the center C of the lens 1.
  • the pads 2 and 3 are fitted with known clamping cylinders 5, one of which is rotated around the axis 4 in the direction A.
  • a grinding wheel 6 for trimming the lens is carried by a support 7 capable of moving it away or bringing it closer (arrow B) to the axis 4 according to a defined program. nor by the contour 8 which it is sought to obtain, and of course the angular displacement of this lens around the axis 4.
  • the trimming device also comprises a probing unit 9 thanks to which the coordinates can be noted in the reference system of the device, of a plurality of points belonging for example to the convex face la of the lens 1.
  • the probing device 9 makes it possible to note the coordinates of the points belonging to the contour 8 that it is sought to obtain, that is to say to the trace of the contour of the frame on the face 1a of the lens 1 when the this one is not subjected to any constraint, therefore in a condition of weak tightening between the pads 2 and 3 represented by the part 2A of figure 2.
  • the coordinates of arcs such as 10, 11, 12 and 13 which are orthogonal meridian arcs extending in the vicinity of the above trace 8.
  • the meridians 10, 12 and 11, 13 are intersecting at the point of intersection of the convex face la of the lens with the axis 4 passing through the center C.
  • the trimming is done conventionally, that is to say that the displacement relative to the axis 4 of the grinding wheel 6 is programmed to progressively reach the profile 8 which has been previously entered into the machine by a copying of the periphery of the chosen frame reported in the reference of the machine, therefore of the lens.
  • the feeler device 9 makes it possible to specify the coordinate along the axis 4 of each point of the final contour of the lens in order to control the position of the grinding wheel along this axis for carrying out a lief on the edge of the lens.
  • the invention consists of a method which makes it possible to obtain the desired profile by trimming the deformed lens under stress. To do this, a plurality of points are taken, two meridian arcs 10, 12 and 13, 11 in a state of weak tightening of the lens which does not cause its deformation. This reading is carried out with the probing device 9 and the coordinates of the points, known in the reference system of the apparatus represented in FIG. 1, make it possible to obtain a mathematical representation in this reference system, of the meridians which comprise on the one hand the arcs 10, 12 and on the other hand the arcs 11, 13.
  • This mathematical representation can be for example a circle which will be one of the large circles of the convex surface la of the lens if the latter is spherical or which can be a mathematical approximation of polynomial form of degree four for example. We have in fact realized that this refinement was sufficient for the precision that we seek in the dimensions of lenses to be obtained.
  • the device 9 in addition to the probing of the meridian arcs, the device 9 proceeds to probing the trace 8 on the lens in its second tightening condition, which makes it possible to determine a law of variation (non-linear interpolation) of the coefficient of correction between two noted meridians.
  • a refinement of the method according to the invention consists in carrying out the readings on the lens deformed by a strong pressure between the pads 2 and 3, after having carried out a rough grinding of the lens.
  • a strong pressure between the pads 2 and 3 there may be along the contour 8 to be obtained, to remove a lot of material at the periphery of the lens.
  • the removal of this material modifies the deformation of the lens with equal tightening so that the readings made before any grinding as in part 2B of FIG. 2, can turn out to be different from those which one realizes after having roughed the part and thus lead to a mathematical representation of the lens which is not representative of the real state of the lens in end of trimming, therefore lead to an incorrect correction of the grinding path.
  • part 2C of Figure 2 there is shown the lens 1 which has undergone a rough roughing.
  • the second probing on, for example, the meridian arcs is carried out on the lens thus pre-cut with the drawback that the meridian arcs are no longer very long, in particular outside the final contour, which can lead to poorer accuracy.
  • the final contour obtained was much closer to the desired contour than when the probing of the lens was carried out. deformed as in part 2B of FIG. 2.
  • part 2C of this figure there are the same references as those previously used to designate identical elements.
  • This part 2C of FIG. 2 shows the probe 9 describing on the lens in its second tightening condition, the programmed theoretical trajectory corresponding to the contour 8 of the frame circle in the frame of reference of the lens. It can be seen that the location of the probing does not correspond to the corrected trajectory, which introduces an error in the position of the grinding wheel in the direction of axis 4, this error resulting in an incorrectly placed relief on the edge of the lens.
  • the mathematical representation of the lens in the two tightening states makes it possible to provide the reading 8 with the correction Z which is suitable for correct machining of the edge of the lens.

Abstract

The invention relates to a method for carrying out the precise trimming of a lens ( 1 ), whereby the lens is held between two clamping plates ( 2, 3 ) in a given position and the grinding of the periphery of the lens ( 1 ) is controlled along a trajectory, the last programmed part of which corresponds to the form ( 8 ) desired for the lens. The method comprises a first scanning under weak clamping conditions of a number of points on one face of the lens with scanning of the coordinates of the points ( 8 ), forming the trace on said face of the mounting circle, a second scanning, with a significant level of clamping which corresponds to that used on trimming the lens of a second number of points on said face of the lens, an approximate mathematical representation of the face of the lens for each of the two clamping conditions, a calculation of the coordinates for the deformation of the contour of the lens on said face of the lens in the second clamping condition to correct the last programmed part of the grinding trajectory.

Description

Procédé de détourage d'un verre de lunette. Method for trimming a spectacle lens.
La présente invention concerne l'usinage d'un contour de verre de lunette pour l'adapter au cercle de monture qui doit le recevoir.The present invention relates to the machining of an outline of spectacle lens to adapt it to the frame circle which is to receive it.
ARRIERE PLAN DE L'INVENTION Un verre de lunette, appelé lentille, qu'il soit ou non correcteur, est issu d'une pièce qui possède toutes les qualités optiques requises pour son usage et no- tamment un centre optique qu'on appellera centre de la lentille. Cette pièce est le plus souvent de contour circulaire, d'un diamètre suffisant pour qu'on puisse y inscrire toutes les formes possibles de périphérie correspondant à l'immense variété des cercles ou entourages de montures existant sur le marché.BACKGROUND OF THE INVENTION A spectacle lens, called a lens, whether or not it is corrective, comes from a part which has all the optical qualities required for its use and in particular an optical center which will be called center of the lens. This part is most often of circular outline, of a sufficient diameter so that one can register there all the possible forms of periphery corresponding to the immense variety of the circles or entourages of frames existing on the market.
Le détourage est l'opération d'usinage qui consiste à réaliser le contour de la lentille adapté à la forme de la monture qui la reçoit. Cet usinage périphérique met en œuvre un outillage dans lequel la lentille est serrée au voisinage de son centre entre deux accessoires de maintien et en général d'entraînement en rotation de la lentille autour d'un axe qui la traverse, alors qu'une meule réalise en général en deux phases, le contour désiré . Les accessoires de serrage de la lentille se présentent sous la forme de patins qui, pressés contre les deux faces concave et convexe de la lentille, engendrent des contraintes et des déformations de cette dernière. L'usinage du contour est donc réalisé sur une lentille déformée sous contrainte qui, à l'état relâché, affectera une forme différente donc un contour différent de celui usiné .Trimming is the machining operation which consists in making the contour of the lens adapted to the shape of the frame which receives it. This peripheral machining implements a tool in which the lens is clamped in the vicinity of its center between two holding accessories and in general driving in rotation of the lens around an axis which passes through it, while a grinding wheel realizes generally in two phases, the desired contour. The lens clamping accessories are in the form of pads which, pressed against the two concave and convex faces of the lens, generate stresses and deformations of the latter. The machining of the contour is therefore carried out on a lens deformed under stress which, in the relaxed state, will affect a different shape therefore a different contour from that machined.
Pour traiter les petites lentilles de forme oblongue, en assurant correctement l'entraînement en ro- tation de la lentille au cours du détourage, il est nécessaire d'utiliser des patins de forme oblongue. Il est en effet contre-indiqué et en tout cas inefficace d'appliquer une pression importante avec un patin de révolution de petite dimension. Or, le serrage asymétrique résultant de l'emploi de patins oblongs engendre imman- quablement une déformation de la lentille.To treat small oblong shaped lenses, ensuring correct rotation of the lens during trimming, it is necessary to use oblong shaped pads. It is indeed contraindicated and in any case ineffective to apply significant pressure with a small size skid of revolution. However, asymmetric tightening resulting from the use of oblong pads inevitably generates a deformation of the lens.
OBJET DE L'INVENTION Par la présente invention, on entend prendre en compte cette déformation en améliorant le processus de détourage d'une lentille, notamment en prévoyant une phase de ce processus par laquelle on détermine un facteur de correction du contour réalisé par meulage pour qu'à l'état relâché la lentille soit détourée au contour désiré et imposé par le cercle de monture, avec une tolérance acceptable. BREVE DESCRIPTION DE L'INVENTIONOBJECT OF THE INVENTION By the present invention, it is intended to take this deformation into account by improving the process of trimming a lens, in particular by providing a phase of this process by which a factor of correction of the contour produced by grinding is determined for that in the relaxed state the lens is cropped to the desired contour and imposed by the frame circle, with an acceptable tolerance. BRIEF DESCRIPTION OF THE INVENTION
A cet effet, l'invention a donc pour objet un procédé pour réaliser le détourage précis d'une lentille aux fins de permettre son montage dans un cercle de monture déterminé, selon lequel on maintient la lentille en- tre deux patins de serrage, dans une position définie et connue dans un repère de référence lié aux patins et on commande le meulage de la périphérie de la lentille le long d'une trajectoire dont la partie terminale programmée correspond sur la lentille à la forme du cercle de monture. Selon l'invention, le procédé comprend :To this end, the invention therefore relates to a method for carrying out the precise trimming of a lens in order to allow its mounting in a determined frame circle, according to which the lens is held between two clamping pads, in a defined and known position in a reference frame linked to the pads and the grinding of the periphery of the lens is controlled along a trajectory whose programmed end part corresponds on the lens to the shape of the frame circle. According to the invention, the method comprises:
- un premier relevé dans une condition de serrage faible d'une pluralité de points appartenant à une face de la lentille,a first reading in a weak clamping condition of a plurality of points belonging to one face of the lens,
- un second relevé, dans une condition de serrage important nécessaire au détourage de la lentille, d'une autre pluralité de points appartenant à la face susdite,- a second reading, in an important tightening condition necessary for trimming the lens, of another plurality of points belonging to the above-mentioned face,
- à partir des relevés susdits, une représentation mathématique approchée de la face de la lentille susdite pour chacune des deux conditions de serrage, - un calcul, au moyen des représentations mathématiques susdites, des coordonnées de points de la transformée de la trace de la forme programmée du cercle de monture sur ladite face de la lentille, transformée ré- sultant de la déformation de la lentille selon un modèle connu lors du passage de la première à la deuxième condition de serrage,- from the abovementioned readings, an approximate mathematical representation of the face of the aforesaid lens for each of the two tightening conditions, a calculation, by means of the abovementioned mathematical representations, of the coordinates of points of the transform of the trace of the programmed shape of the frame circle on said face of the lens, transform resulting from the deformation of the lens according to a known model when switching from the first to the second tightening condition,
- une correction de chacun des points de la trajectoire programmée de meulage définie par l'écart entre les coordonnées programmées et les coordonnées calculées. C'est grâce au passage par des représentations mathématiques d'une face de la lentille que l'on peut parvenir à corriger la trajectoire de détourage. En effet, seule une représentation mathématique de cette face ou d'une pluralité de lignes de cette face permet d'obtenir la valeur des coordonnées d'un point immobile sur cette surface mais ayant bougé avec elle dans le repère du poste de travail lors du changement de la condition de serrage. Il est alors possible de former des mo- dèles représentant la réalité physique des phénomènes engendrés par la modification du serrage. Par exemple on peut considérer que la modification de forme se fait sans modification de l'aire de la surface de la face objet des relevés (face palpée), si bien que l'arc qui, sur cette face relie le point considéré à un centre de la lentille, sera de longueur identique pour les deux conditions de serrage. Si ce point appartient au contour de la lentille c'est-à-dire à la forme programmée du cercle de monture dans le repère de référence, il constituera le point, aux coordonnées connues par le calcul, par lequel devra passer la meule de détourage alors que la lentille est déformée par le serrage. Ces coordonnées, rapportées aux coordonnées d'une trajectoire théorique qui correspond au détourage d'une lentille non déformée, permettent de déterminer un coefficient correcteur de cette trajectoire théorique .- a correction of each of the points on the programmed grinding path defined by the difference between the programmed coordinates and the calculated coordinates. It is through the passage through mathematical representations of one face of the lens that we can manage to correct the clipping path. Indeed, only a mathematical representation of this face or of a plurality of lines of this face makes it possible to obtain the value of the coordinates of a point stationary on this surface but having moved with it in the reference frame of the work station during the change of the tightening condition. It is then possible to form models representing the physical reality of the phenomena generated by the modification of the tightening. For example we can consider that the modification of shape is done without modification of the surface area of the face object of the surveys (palpated face), so that the arc which, on this face connects the point considered to a center of the lens, will be of identical length for the two tightening conditions. If this point belongs to the contour of the lens, that is to say to the programmed shape of the frame circle in the reference frame, it will constitute the point, at the coordinates known by the calculation, through which the clipping wheel will have to pass. while the lens is deformed by tightening. These coordinates, compared to the coordinates of a theoretical trajectory which corresponds to the clipping of an undeformed lens, allow to determine a correction coefficient for this theoretical trajectory.
De manière préférée, le relevé des coordonnées des points de la face déformée sera réalisé après qu'un détourage d'ébauche aura été réalisé. En effet, la déformation de la lentille, sous l'effet du serrage, varie avec la quantité de matière mise en jeu et notamment avec la dimension suivant le rayon de cette lentille. Ainsi, pour un effort de serrage identique appliqué au centre de la lentille, on constate des déformations différentes de la lentille selon que la périphérie de cette dernière est proche ou loin du centre .Preferably, the statement of the coordinates of the points of the deformed face will be carried out after a rough outline has been produced. Indeed, the deformation of the lens, under the effect of tightening, varies with the amount of material involved and in particular with the dimension along the radius of this lens. Thus, for an identical clamping force applied to the center of the lens, there are different deformations of the lens depending on whether the periphery of the latter is near or far from the center.
Dans un mode de réalisation simplifié de l'invention, la représentation mathématique de la forme de la face de la lentille est réalisée par l'approximation mathématique de la forme d'au moins un arc méridien de cette lentille, c'est-à-dire de la ligne de la surface (par exemple convexe) de la lentille qui court entre le centre de celle-ci et un point quelconque de cette surface (on pourrait dire l'arc orthodromique entre le centre et le point considéré) et notamment un point du contour programmé du cercle de monture dans l'état non déformé de la lentille. Plus précisément, dans ce mode de réalisation simplifié du procédé selon l'invention, le premier relevé comprend le palpage des points de la face susdite de la lentille appartenant à au moins un arc méridien, dans une zone voisine de la trace susdite, afin de déterminer une approximation mathématique de la forme de cet arc méridien, le second relevé concerne des points de cet arc méridien déjà palpé afin de déterminer une approximation mathématique de la forme de cet arc, corrélée à la première approximation, tandis que le calcul et la correction susdits consistent à calculer la valeur des coordonnées du point de l'arc méri- dien appartenant au contour programmé du cercle de mon- ture dans la représentation mathématique de l'arc méridien sous contrainte déformante et à corriger la partie terminale de la trajectoire de la meule d'un coefficient tiré de l'écart entre les coordonnées programmées et les coordonnées calculées de ce point d'intersection.In a simplified embodiment of the invention, the mathematical representation of the shape of the face of the lens is carried out by the mathematical approximation of the shape of at least one meridian arc of this lens, that is to say say the line of the surface (for example convex) of the lens which runs between the center of this one and any point of this surface (one could say the orthodromic arc between the center and the point considered) and in particular a point of the programmed contour of the frame circle in the undeformed state of the lens. More specifically, in this simplified embodiment of the method according to the invention, the first reading comprises the probing of the points of the above-mentioned face of the lens belonging to at least one meridian arc, in an area close to the above-mentioned trace, in order to determine a mathematical approximation of the shape of this meridian arc, the second reading concerns points of this meridian arc already palpated in order to determine a mathematical approximation of the shape of this arc, correlated to the first approximation, while the calculation and the correction aforementioned consist in calculating the value of the coordinates of the point of the meridian arc belonging to the programmed contour of the circle of ture in the mathematical representation of the meridian arc under deforming stress and to correct the terminal part of the trajectory of the grinding wheel by a coefficient drawn from the difference between the programmed coordinates and the calculated coordinates of this point of intersection.
Dans ce qui précède on a évoqué l'hypothèse selon laquelle la face palpée se déforme, entre les deux conditions de serrage, à aire constante c'est-à-dire sans allongement ou rétrécissement d'une dimension surfacique quelconque. D'autres modèles sont envisageables tel par exemple que celui selon lequel la déformation de la lentille entre deux états de serrage est à aire constante pour une surface virtuelle interne contenant les « fibres neutres » de la lentille, sa face convexe subissant un allongement par rapport à cette « surface neutre » et la face concave, un rétrécissement. Une quantification de cet allongement peut être alors prise en compte dans le calcul des corrections.In the foregoing, reference has been made to the hypothesis that the palpated face deforms, between the two clamping conditions, at a constant area, that is to say without elongation or shrinkage of any surface dimension. Other models are conceivable such as that according to which the deformation of the lens between two tightening states is at constant area for an internal virtual surface containing the “neutral fibers” of the lens, its convex face undergoing an elongation with respect to to this "neutral surface" and the concave face, a narrowing. A quantification of this elongation can then be taken into account in the calculation of the corrections.
On notera que, dans ce qui précède, le contour programmé du cercle de monture (ou la trajectoire théorique de la meule pour sa réalisation) correspond en réalité à une enveloppe cylindrique dont les génératrices, parallèles à l'axe de serrage de la lentille, s'appuient sur ce contour. En d'autres termes, on ne s'est pas sou- cié dans ce qui précède, de la coordonnée de chaque point de ce contour selon la direction de cet axe ou de ces génératrices. Pour être complet, un détourage de verre demande la réalisation d'un relief sur le chant de la lentille (soit en creux pour le passage d'un lien de cer- clage soit en bosse pour pénétrer dans le drageoir du cercle de monture) . Ce relief est réalisé par la forme du chant de la meule qu'il faut donc piloter en position le long de la direction susdite pour le maintenir toujours en face du chant de la lentille. Pour permettre ce pilo- tage et ce de manière précise, il convient donc de rele- ver les coordonnées des points de la projection du contour programmé sur la lentille et notamment la coordonnée le long de l'axe de serrage de chacun de ces points. Ce relevé peut être réalisé dans l'une ou l'autre des condi- tions de serrage de la lentille et par un calcul réalisé à partir de ce relevé et des représentations mathématiques de la surface de palpage de la lentille, on détermine les paramètres de ce pilotage en position le long de la direction de serrage pour tenir compte de la déforma- tion de la lentille lors de son détourage. Ces paramètres s'ajoutent à ceux qui, comme dit précédemment, ont déterminé la trajectoire finale de la meule dans la commande de la machine.It will be noted that, in the foregoing, the programmed contour of the mounting circle (or the theoretical trajectory of the grinding wheel for its production) actually corresponds to a cylindrical envelope whose generatrices, parallel to the axis of tightening of the lens, build on this outline. In other words, we have not worried in what precedes, of the coordinate of each point of this contour according to the direction of this axis or these generatrices. To be complete, a clipping of the glass requires the creation of a relief on the edge of the lens (either in the hollow for the passage of a strapping link or in a bump to enter the bezel of the frame circle). This relief is produced by the shape of the edge of the grinding wheel which must therefore be controlled in position along the above-mentioned direction in order to keep it always opposite the edge of the lens. To allow this piloting and this in a precise way, it is therefore advisable to ver the coordinates of the points of the projection of the contour programmed on the lens and in particular the coordinate along the tightening axis of each of these points. This reading can be carried out under one or the other of the tightening conditions of the lens and by a calculation carried out from this reading and mathematical representations of the probing surface of the lens, the parameters of this piloting in position along the tightening direction to take account of the deformation of the lens during its trimming. These parameters are in addition to those which, as said previously, determined the final trajectory of the grinding wheel in the control of the machine.
D'autres caractéristiques et avantages de l'invention ressortiront de la description d'un mode de réalisation du procédé de détourage d'une lentille de lunette donné ci-après à titre non limitatif. BREVE DESCRIPTION DES DESSINS Il sera fait référence aux dessins annexés, parmi lesquels :Other characteristics and advantages of the invention will emerge from the description of an embodiment of the trimming method for a spectacle lens given below without implied limitation. BRIEF DESCRIPTION OF THE DRAWINGS Reference will be made to the appended drawings, among which:
- la figure 1 est un schéma illustrant un appareillage de détourage d'une lentille de lunette,FIG. 1 is a diagram illustrating a device for trimming a spectacle lens,
- la figure 2 est une schéma illustrant les différentes phases du procédé selon l'invention. DESCRIPTION DETAILLEE DE L'INVENTION- Figure 2 is a diagram illustrating the different phases of the method according to the invention. DETAILED DESCRIPTION OF THE INVENTION
De manière connue, comme représenté aux figures, une lentille 1 sensiblement circulaire, est serrée entre deux patins 2 et 3 de manière à pouvoir être entraînée en rotation autour d'un axe 4 qui passe par le centre C de la lentille 1. Les patins 2 et 3 équipent des vérins de serrage 5 connus, dont l'un est animé d'un mouvement de rotation autour de l'axe 4 dans le sens A.In known manner, as shown in the figures, a substantially circular lens 1 is clamped between two pads 2 and 3 so that it can be rotated about an axis 4 which passes through the center C of the lens 1. The pads 2 and 3 are fitted with known clamping cylinders 5, one of which is rotated around the axis 4 in the direction A.
Une meule 6 de détourage de la lentille est portée par un support 7 susceptible de l'éloigner ou de la rapprocher (flèche B) de l'axe 4 selon un programme défi- ni par le contour 8 que l'on cherche à obtenir, et bien entendu le déplacement angulaire de cette lentille autour de 1 ' axe 4.A grinding wheel 6 for trimming the lens is carried by a support 7 capable of moving it away or bringing it closer (arrow B) to the axis 4 according to a defined program. nor by the contour 8 which it is sought to obtain, and of course the angular displacement of this lens around the axis 4.
Le dispositif de détourage comporte également une unité de palpage 9 grâce à laquelle on peut relever les coordonnées dans le système de référence de l'appareil, d'une pluralité de points appartenant par exemple à la face convexe la de la lentille 1. En particulier, le dispositif de palpage 9 permet de relever les coordonnées des points appartenant au contour 8 que l'on cherche à obtenir c'est-à-dire à la trace du contour de la monture sur la face la de la lentille 1 lorsque celle-ci n'est soumise à aucune contrainte, donc dans une condition de serrage faible entre les patins 2 et 3 représentée par la partie 2A de la figure 2. Il permet ainsi de relever les coordonnées d'arcs tels que 10, 11, 12 et 13 qui sont des arcs méridiens orthogonaux s 'étendant au voisinage de la trace 8 susdite. Les méridiens 10, 12 et 11, 13 sont sécants au point d'intersection de la face convexe la de la lentille avec l'axe 4 passant par le centre C.The trimming device also comprises a probing unit 9 thanks to which the coordinates can be noted in the reference system of the device, of a plurality of points belonging for example to the convex face la of the lens 1. In particular , the probing device 9 makes it possible to note the coordinates of the points belonging to the contour 8 that it is sought to obtain, that is to say to the trace of the contour of the frame on the face 1a of the lens 1 when the this one is not subjected to any constraint, therefore in a condition of weak tightening between the pads 2 and 3 represented by the part 2A of figure 2. It thus makes it possible to note the coordinates of arcs such as 10, 11, 12 and 13 which are orthogonal meridian arcs extending in the vicinity of the above trace 8. The meridians 10, 12 and 11, 13 are intersecting at the point of intersection of the convex face la of the lens with the axis 4 passing through the center C.
Si le matériau qui constitue la lentille 1 est suffisamment rigide et/ou si l'épaisseur de la lentille est suffisamment importante, on peut appliquer à celle-ci un effort de serrage qui n'entraîne pratiquement pas de contraintes donc de déformation de cette lentille. Dans ces conditions le détourage se fait classiquement, c'est- à-dire que le déplacement par rapport à l'axe 4 de la meule 6 est programmé pour atteindre progressivement le profil 8 qui a été préalablement entré dans la machine par un copiage de la périphérie de la monture choisie rapporté dans le repère de la machine, donc de la lentille. Le dispositif de palpage 9 permet dans ce cas de préciser la coordonnée suivant l'axe 4 de chaque point du contour final de la lentille pour piloter la position de la meule le long de cet axe pour la réalisation d'un re- lief sur le chant de la lentille.If the material constituting the lens 1 is sufficiently rigid and / or if the thickness of the lens is sufficiently large, a clamping force may be applied thereto which practically does not cause any stress, therefore deformation of this lens . Under these conditions, the trimming is done conventionally, that is to say that the displacement relative to the axis 4 of the grinding wheel 6 is programmed to progressively reach the profile 8 which has been previously entered into the machine by a copying of the periphery of the chosen frame reported in the reference of the machine, therefore of the lens. In this case, the feeler device 9 makes it possible to specify the coordinate along the axis 4 of each point of the final contour of the lens in order to control the position of the grinding wheel along this axis for carrying out a lief on the edge of the lens.
Mais dans la plupart des cas, l'effort de serrage des patins induit une déformation de la lentille qui n'est pas négligeable par rapport à la forme de cette lentille sans serrage. On comprend de la partie 2B de la figure 2 que si on procède comme dit précédemment sur la lentille déformée, on obtiendra après relâchement de l'effort de serrage une lentille dont le contour 8' ne correspond pas au contour désiré 8. La lentille sera trop grande.But in most cases, the clamping force of the pads induces a deformation of the lens which is not negligible compared to the shape of this lens without clamping. It is understood from part 2B of FIG. 2 that if one proceeds as said above on the deformed lens, one will obtain, after release of the clamping force, a lens whose contour 8 'does not correspond to the desired contour 8. The lens will be too big.
L'invention consiste en un procédé qui permet d'obtenir le profil désiré par détourage de la lentille déformée sous contrainte. Pour ce faire on procède à un relevé d'une pluralité de points deux arcs méridiens 10, 12 et 13, 11 dans un état de faible serrage de la lentille qui n'entraîne pas de déformation de celle-ci. Ce relevé est réalisé avec le dispositif de palpage 9 et les coordonnées des points, connues dans le système de référence de l'appareillage représenté à la figure 1, permet- tent d'obtenir une représentation mathématique dans ce système de référence, des méridiens qui comprennent d'une part les arc 10, 12 et d'autre part les arcs 11, 13. Cette représentation mathématique peut être par exemple un cercle qui sera un des grands cercles de la surface convexe la de la lentille si celle-ci est spherique ou qui peut être une approximation mathématique de forme po- lynomiale de degré quatre par exemple. On s'est en effet rendu compte que ce raffinement était suffisant pour la précision que l'on recherche dans les dimensions de len- tilles à obtenir.The invention consists of a method which makes it possible to obtain the desired profile by trimming the deformed lens under stress. To do this, a plurality of points are taken, two meridian arcs 10, 12 and 13, 11 in a state of weak tightening of the lens which does not cause its deformation. This reading is carried out with the probing device 9 and the coordinates of the points, known in the reference system of the apparatus represented in FIG. 1, make it possible to obtain a mathematical representation in this reference system, of the meridians which comprise on the one hand the arcs 10, 12 and on the other hand the arcs 11, 13. This mathematical representation can be for example a circle which will be one of the large circles of the convex surface la of the lens if the latter is spherical or which can be a mathematical approximation of polynomial form of degree four for example. We have in fact realized that this refinement was sufficient for the precision that we seek in the dimensions of lenses to be obtained.
Avec cette représentation mathématique de deux méridiens, ou plus si on le souhaite sachant que les relevés sont consommateurs de temps et qu'il convient de trouver le meilleur compromis entre la précision à at- teindre et le temps passé pour l'obtenir, il est facile de calculer la longueur qui sépare par exemple le centre C par lequel passent les deux méridiens des points d'intersection 10a, lia, 12a et 13a. de ces méridiens avec la trace 8 du contour à réaliser. En formant l'hypothèse que la longueur de ces méridiens ne varie pas lorsque la lentille se déforme (on est donc dans une déformation surfacique à surface ou aire conservée, donc dans une déformation linéaire à longueur conservée) , on sait que le bord final de la len- tille détourée sera, à l'endroit de chaque méridien, distant du centre d'une longueur de l'arc égale à celle calculée. Ainsi, si on procède à nouveau à un relevé des arcs tels que 10, 11, 12 et 13 sur la face extérieure la de la lentille alors que celle-ci est déformée sous l'effet d'un effort de serrage important et nécessaire à son usinage tel que représenté en partie 2B de la figure 2, on peut à nouveau trouver une représentation mathématique de ces méridiens s 'exprimant par exemple sous la forme de l'équation d'un cercle ou d'un polynôme encore une fois de degré quatre, et en imposant à cette équation une valeur qui correspond à la longueur d'arc calculée précédemment, on trouvera les coordonnées dans le repère de l'outillage de détourage des points par où la meule devra passer pour que, en dernier lieu, lorsque la len- tille sera soustraite à ces contraintes de compression, le bord de cette lentille soit confondu avec la trace 8 susdite. Ce point calculé est représenté en 8 ' ' à la partie 2B de la figure 2, ce qui permet de déterminer la valeur E de laquelle on doit modifier la commande de la meule 6 par rapport à sa programmation qui a été faite, la lentille étant supposée indéformée et indéformable.With this mathematical representation of two meridians, or more if desired, knowing that the readings are time consuming and that it is necessary to find the best compromise between the precision to be reached and the time spent to obtain it, it is easy to calculate the length which separates for example the center C through which the two meridians pass the points of intersection 10a, 11a, 12a and 13a. of these meridians with trace 8 of the contour to be produced. By forming the hypothesis that the length of these meridians does not vary when the lens deforms (we are therefore in a surface deformation with a preserved surface or area, therefore in a linear deformation with preserved length), we know that the final edge of the clipped lens will be, at the location of each meridian, distant from the center with a length of the arc equal to that calculated. Thus, if we again carry out a reading of the arcs such as 10, 11, 12 and 13 on the external face 1a of the lens while the latter is deformed under the effect of a significant clamping force and necessary to its machining as represented in part 2B of figure 2, one can again find a mathematical representation of these meridians being expressed for example in the form of the equation of a circle or a polynomial once again of degree four, and by imposing on this equation a value which corresponds to the arc length calculated previously, one will find the coordinates in the reference frame of the clipping tool of the points through which the grinding wheel will have to pass so that, lastly, when the lens will be subtracted from these compression stresses, the edge of this lens is merged with the aforementioned trace 8. This calculated point is represented in 8 '' in part 2B of FIG. 2, which makes it possible to determine the value E by which the control of the grinding wheel 6 must be modified in relation to its programming which has been made, the lens being supposed to be undeformed and undeformable.
On notera à ce propos que la programmation susdite correspond en réalité à la définition d'une partie terminale d'une trajectoire entre la meule et la lentille animée de son mouvement de rotation A autour de l'axe 4 ; l'autre partie (initiale) de cette trajectoire résulte d'une programmation d'approche.It will be noted in this connection that the above programming actually corresponds to the definition of a terminal part of a trajectory between the grinding wheel and the lens animated by its rotational movement A around the axis 4; the other (initial) part of this trajectory results from an approach programming.
On a décrit ci-dessus le palpage et la représentation mathématique de deux méridiens. On obtient donc une correction pour quatre points du contour. Or, il est entendu qu'il faut corriger le contour sur sa longueur continue. Plusieurs méthodes sont alors disponibles pour obtenir un coefficient de correction pour chacun des points du contour. Une première d'entre elles consiste à pratiquer une interpolation linéaire entre chacune des valeurs E obtenues au droit des méridiens de palpage. Cette méthode donne de bons résultats lorsque la lentille possède des faces concaves et convexes dont les surfaces sont de révolution autour de l'axe 4. Dans le cas où la face concave est une face cylindrique ou torique, la lentille n'est plus de révolution autour de l'axe qui passe par son centre et une interpolation linéaire entre les quatre points de mesure peut être de précision insuffisante. Dans ce cas, à l'état déformé représenté par la partie 2B de la figureThe probing and the mathematical representation of two meridians have been described above. We therefore obtain a correction for four points of the contour. However, it is understood that the contour must be corrected over its continuous length. Several methods are then available to obtain a correction coefficient for each point of the contour. A first of these consists in practicing a linear interpolation between each of the E values obtained in line with the probing meridians. This method gives good results when the lens has concave and convex faces whose surfaces are of revolution around the axis 4. In the case where the concave face is a cylindrical or toric face, the lens is no longer of revolution around the axis which passes through its center and a linear interpolation between the four measurement points may be of insufficient precision. In this case, in the deformed state represented by part 2B of the figure
2, outre le palpage des arcs méridiens, on procède par le dispositif 9 à un palpage de la trace 8 sur la lentille dans sa deuxième condition de serrage, ce qui permet de pouvoir déterminer une loi de variation (interpolation non linéaire) du coefficient de correction entre deux méridiens relevés .2, in addition to the probing of the meridian arcs, the device 9 proceeds to probing the trace 8 on the lens in its second tightening condition, which makes it possible to determine a law of variation (non-linear interpolation) of the coefficient of correction between two noted meridians.
Un raffinement du procédé selon l'invention consiste à procéder aux relevés sur la lentille déformée par une forte pression entre les patins 2 et 3 , après avoir procédé à un meulage d'ébauche de la lentille. Comme on le constate à la figure 1, il peut y avoir selon le contour 8 à obtenir, à retirer beaucoup de matière en périphérie de la lentille. Le retrait de cette matière modifie à serrage égal la déformée de la lentille si bien que les relevés réalisés avant tout meulage comme à la partie 2B de la figure 2, peuvent s'avérer différents de ceux que l'on réalise après avoir ébauché la pièce et donc conduire à une représentation mathématique de la lentille qui n'est pas représentative de l'état réel de la len- tille en fin de détourage, donc conduire à une correction erronée de la trajectoire de meulage. A la partie 2C de la figure 2, on a représenté la lentille 1 qui a subi un ébauchage grossier. Le deuxième palpage sur par exemple les arcs méridiens est réalisé sur la lentille ainsi pré- taillée avec l'inconvénient que les arcs méridiens ne sont plus très longs, notamment à l'extérieur du contour final, ce qui peut conduire à une moins bonne précision dans l'approximation mathématique des formes. On a cependant constaté que malgré le manque d'espace permettant de procéder à des relevés assez nombreux pour obtenir une approximation mathématique importante, le contour final obtenu s'approchait beaucoup plus du contour désiré que lorsque l'on avait procédé au palpage de la lentille déformée comme à la partie 2B de la figure 2. A la partie 2C de cette figure, on retrouve les mêmes références que celles précédemment utilisées pour désigner des éléments identiques .A refinement of the method according to the invention consists in carrying out the readings on the lens deformed by a strong pressure between the pads 2 and 3, after having carried out a rough grinding of the lens. As can be seen in Figure 1, there may be along the contour 8 to be obtained, to remove a lot of material at the periphery of the lens. The removal of this material modifies the deformation of the lens with equal tightening so that the readings made before any grinding as in part 2B of FIG. 2, can turn out to be different from those which one realizes after having roughed the part and thus lead to a mathematical representation of the lens which is not representative of the real state of the lens in end of trimming, therefore lead to an incorrect correction of the grinding path. In part 2C of Figure 2, there is shown the lens 1 which has undergone a rough roughing. The second probing on, for example, the meridian arcs is carried out on the lens thus pre-cut with the drawback that the meridian arcs are no longer very long, in particular outside the final contour, which can lead to poorer accuracy. in the mathematical approximation of forms. However, it has been found that despite the lack of space allowing numerous enough readings to obtain a large mathematical approximation, the final contour obtained was much closer to the desired contour than when the probing of the lens was carried out. deformed as in part 2B of FIG. 2. In part 2C of this figure, there are the same references as those previously used to designate identical elements.
Sur cette partie 2C de la figure 2 on a représenté le palpeur 9 décrivant sur la lentille dans sa deuxième condition de serrage, la trajectoire théorique programmée correspondant au contour 8 du cercle de monture dans le référentiel de la lentille. On constate que le lieu du palpage ne correspond pas à la trajectoire corrigée, ce qui introduit une erreur de position de la meule dans la direction de l'axe 4, cette erreur ayant pour conséquence une réalisation incorrectement placée d'un relief sur le chant de la lentille. La représentation mathématique de la lentille dans les deux états de serrage permet d'apporter au relevé 8 la correction Z qui convient à un usinage correct du chant de la lentille. This part 2C of FIG. 2 shows the probe 9 describing on the lens in its second tightening condition, the programmed theoretical trajectory corresponding to the contour 8 of the frame circle in the frame of reference of the lens. It can be seen that the location of the probing does not correspond to the corrected trajectory, which introduces an error in the position of the grinding wheel in the direction of axis 4, this error resulting in an incorrectly placed relief on the edge of the lens. The mathematical representation of the lens in the two tightening states makes it possible to provide the reading 8 with the correction Z which is suitable for correct machining of the edge of the lens.

Claims

REVENDICATIONS
1. Procédé pour réaliser le détourage précis d'une lentille (1) aux fins de permettre son montage dans un cercle de monture déterminé, selon lequel on maintient la lentille entre deux patins de serrage (2, 3) dans une position définie dans un repère de référence lié aux patins et on commande le meulage de la périphérie de la lentille (1) le long d'une trajectoire dont la partie terminale programmée correspond sur la lentille à la forme (8) du contour du cercle de monture, caractérisé en ce qu'il comprend :1. Method for carrying out the precise trimming of a lens (1) in order to allow its mounting in a determined frame circle, according to which the lens is maintained between two clamping pads (2, 3) in a position defined in a reference mark linked to the pads and the grinding of the periphery of the lens (1) is controlled along a trajectory whose programmed end part corresponds on the lens to the shape (8) of the outline of the frame circle, characterized in what he understands:
- un premier relevé dans une condition de serrage faible d'une pluralité de points appartenant à une face de la lentille,a first reading in a weak clamping condition of a plurality of points belonging to one face of the lens,
- un second relevé, dans une condition de serrage important, nécessaire au détourage de la lentille, d'une autre pluralité de points de la face susdite de la lentille, - à partir des relevés susdits, une représentation mathématique approchée de la face de la lentille susdite pour chacune des deux conditions de serrage,- a second reading, in a significant tightening condition, necessary for trimming the lens, of another plurality of points on the above-mentioned face of the lens, - from the above-mentioned readings, an approximate mathematical representation of the face of the said lens for each of the two tightening conditions,
- un calcul, au moyen des représentations mathématiques susdites, des coordonnées de points de la trans- formée de la trace de la forme programmée du cercle de monture sur ladite face de la lentille, transformée résultant de la déformation de la lentille selon un modèle connu lors du passage de la première à la deuxième condition de serrage, - une correction de chacun des points de la trajectoire programmée de meulage définie par l'écart entre les coordonnées programmées et les coordonnées calculées.a calculation, by means of the abovementioned mathematical representations, of the coordinates of points of the transform of the trace of the programmed shape of the frame circle on said face of the lens, transformed resulting from the deformation of the lens according to a known model during the transition from the first to the second tightening condition, - a correction of each of the points of the programmed grinding path defined by the difference between the programmed coordinates and the calculated coordinates.
2. Procédé selon la revendication 1, caractérisé en ce que le premier relevé comprend le palpage des points de cette face appartenant à au moins un arc méri- dien, dans une zone voisine de cette trace, y compris le point d'intersection de cet arc méridien avec cette trace, afin de déterminer une approximation mathématique de la forme de cet arc méridien, en ce que le second re- levé comprend le palpage de points de l'arc méridien déjà palpé afin de déterminer une approximation mathématique de la forme de cet arc, corrélée à la première approximation, et en ce que le calcul et la correction susdits consistent à calculer la valeur des coordonnées du point d'intersection de la trace et de l'arc méridien dans la représentation mathématique de l'arc méridien sous contrainte déformante et à corriger la partie terminale de la trajectoire de la meule d'un coefficient tiré de l'écart entre les coordonnées relevées et les coordonnées calculées de ce point d'intersection.2. Method according to claim 1, characterized in that the first reading comprises the probing of the points of this face belonging to at least one meri arc dien, in an area close to this trace, including the point of intersection of this meridian arc with this trace, in order to determine a mathematical approximation of the shape of this meridian arc, in that the second survey includes probing points of the meridian arc already palpated in order to determine a mathematical approximation of the shape of this arc, correlated to the first approximation, and in that the above calculation and correction consist in calculating the value of the coordinates of the point of intersection of the trace and the meridian arc in the mathematical representation of the meridian arc under deforming stress and to correct the terminal part of the trajectory of the grinding wheel by a coefficient drawn from the difference between the measured coordinates and the calculated coordinates from this point of intersection.
3. Procédé selon la revendication 1 ou la revendication 2, caractérisé en ce que le second palpage est réalisé après une phase de détourage d'ébauche de la lentille. 3. Method according to claim 1 or claim 2, characterized in that the second probing is carried out after a rough trimming phase of the lens.
4. Procédé selon la revendication 2 ou la revendication 3, caractérisé en ce que l'approximation mathématique est une approximation polynomiale.4. Method according to claim 2 or claim 3, characterized in that the mathematical approximation is a polynomial approximation.
5. Procédé selon l'une quelconque des revendications 2 à 4, caractérisé en ce que le palpage des arcs méridien est réalisé sur quatre arcs décalés de 90° autour du centre (C) de la lentille (1) .5. Method according to any one of claims 2 to 4, characterized in that the probing of the meridian arcs is carried out on four arcs offset by 90 ° around the center (C) of the lens (1).
6. Procédé selon la revendication 5, caractérisé en ce que la détermination du coefficient de correction susdit pour chaque point de la trajectoire situé entre deux arcs méridiens palpés adjacents est réalisée par interpolation linéaire.6. Method according to claim 5, characterized in that the determination of the abovementioned correction coefficient for each point of the trajectory situated between two adjacent palpated meridian arcs is carried out by linear interpolation.
7. Procédé selon la revendication 1, caractérisé en ce qu'il comprend un relevé de la trace du contour de la monture sur la face susdite de la lentille. 7. Method according to claim 1, characterized in that it comprises a reading of the trace of the outline of the frame on the aforesaid face of the lens.
8. Procédé selon les revendications 5 et 7, ca- ractérisé en ce que la détermination du coefficient de correction susdit de la trajectoire entre deux arcs méridiens palpés adjacents est réalisé par une formule d'interpolation déterminée à partir des données relevées lors de palpage de cette trace. 8. Method according to claims 5 and 7, ca- characterized in that the determination of the abovementioned correction coefficient of the trajectory between two adjacent palpated meridian arcs is carried out by an interpolation formula determined from the data recorded during probing of this trace.
EP04742330A 2003-03-27 2004-03-24 Method for trimming a spectacle lens Expired - Lifetime EP1606078B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR0303764 2003-03-27
FR0303764A FR2852877B1 (en) 2003-03-27 2003-03-27 METHOD FOR DETOURING A GLASS OF A GLASSES
PCT/FR2004/000720 WO2004087373A1 (en) 2003-03-27 2004-03-24 Method for trimming a spectacle lens

Publications (2)

Publication Number Publication Date
EP1606078A1 true EP1606078A1 (en) 2005-12-21
EP1606078B1 EP1606078B1 (en) 2011-08-03

Family

ID=32947206

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04742330A Expired - Lifetime EP1606078B1 (en) 2003-03-27 2004-03-24 Method for trimming a spectacle lens

Country Status (8)

Country Link
US (1) US7253974B2 (en)
EP (1) EP1606078B1 (en)
JP (1) JP4050766B2 (en)
KR (1) KR100707944B1 (en)
CN (1) CN100443261C (en)
AT (1) ATE518621T1 (en)
FR (1) FR2852877B1 (en)
WO (1) WO2004087373A1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5073338B2 (en) * 2007-03-28 2012-11-14 株式会社ニデック Lens fixing cup
CN101391389B (en) * 2007-09-21 2012-05-23 鸿富锦精密工业（深圳）有限公司 Rolling device and method
FR2940161B1 (en) * 2008-12-19 2010-12-31 Essilor Int DEVICE AND METHOD FOR MACHINING AN OPHTHALMIC LENS
FR2950161B1 (en) * 2009-09-14 2011-10-07 Essilor Int METHOD FOR PRODUCING A DISTRIBUTION SETTING OF AN OPHTHALMIC LENS FOR MOUNTING IT ON A SEMI-CIRCLED EYEGLASS FRAME.
FR2962676B1 (en) * 2010-07-13 2012-08-03 Essilor Int METHOD FOR DETOURING AN OPHTHALMIC LENS OF LENSES COMPRISING A COATING FILM
CN102172869B (en) * 2011-03-30 2013-06-19 铁道第三勘察设计院集团有限公司 Vision-based track plate numerical controlled grinder optimization grinding method
JP5342665B2 (en) * 2012-03-12 2013-11-13 ファナック株式会社 Lens shape processing method and lens shape processing apparatus for measuring along spiral measurement path
TWI739569B (en) * 2019-09-06 2021-09-11 明達醫學科技股份有限公司 Method of calibrating eyeglass lens processing apparatus
CN113971262B (en) * 2021-10-22 2023-05-05 西南交通大学 Drill tip chip flute grinding track calculation method

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06325697A (en) * 1993-05-14 1994-11-25 Matsushita Electron Corp Color plasma display panel
JP3241241B2 (en) * 1995-08-09 2001-12-25 三菱重工業株式会社 Hollow gas turbine blades
JP3730406B2 (en) * 1998-04-30 2006-01-05 株式会社ニデック Eyeglass lens processing equipment
US6325697B1 (en) * 1999-11-24 2001-12-04 Glassline Corporation CNC machine tools
CN1223436C (en) * 2002-08-07 2005-10-19 刘康 Grinding method and device for optic lens

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2004087373A1 *

Also Published As

Publication number Publication date
FR2852877B1 (en) 2005-05-06
KR100707944B1 (en) 2007-04-13
CN1764518A (en) 2006-04-26
KR20060005347A (en) 2006-01-17
JP2006514584A (en) 2006-05-11
EP1606078B1 (en) 2011-08-03
FR2852877A1 (en) 2004-10-01
ATE518621T1 (en) 2011-08-15
CN100443261C (en) 2008-12-17
US7253974B2 (en) 2007-08-07
JP4050766B2 (en) 2008-02-20
WO2004087373A1 (en) 2004-10-14
US20070097525A1 (en) 2007-05-03

Similar Documents

Publication Publication Date Title
EP0439394B1 (en) Process for the production of an artificial ophthalmic lens, and corresponding artificial ophthalmic lens
EP2750830B1 (en) Method of surfacing a surface of a spectacle lens
FR2912820A1 (en) Ophthalmic element i.e. spectacle lens, realizing method for correcting peripheral or foveal vision of carrier, involves determining power-distribution to realize correction in zone determined with increased size according to amplitude
EP1606078B1 (en) Method for trimming a spectacle lens
EP2247407B1 (en) Method for preparing an ophthalmic lens with specific machining of the fitting rib thereof
WO2007128904A1 (en) Method and device for trimming a lens by cutting said lens
EP3013594B1 (en) Method and apparatus for producing an ophthalmic lens comprising a step of laser marking in order to produce permanent etchings on one surface of said ophthalmic lens
EP2210703B1 (en) Eyeglass lens processing apparatus
FR2525138A1 (en) APPARATUS FOR MACHINING OPTICAL LENSES
WO2013045769A1 (en) Method for trimming an opthalmic lens
EP2234758B9 (en) Method for preparing an ophthalmic lens with specific machining of the fitting rib thereof
FR2964336A1 (en) METHOD FOR DISTRESSING AN OPHTHALMIC LENS
FR2930050A1 (en) APPARATUS FOR READING THE GEOMETRY OF A CIRCLE OR ARCADE OF EYEGLASS MOUNT AND READING METHOD THEREOF
WO2007065981A2 (en) Grinder auto-calibration method
FR2894504A1 (en) METHOD FOR PRODUCING A DETOURAGE SETTING OF AN OPHTHALMIC LENS
EP1435342B1 (en) Process and apparatus for controlling the polarisation mode dispersion of an optical fibre during drawing
EP1996368A1 (en) Method of controlling a probe for reading the groove in a spectacle frame rim and corresponding reading apparatus
EP2846969A1 (en) Method for cutting-out a multi-layer ophthalmic lens
EP2247408B1 (en) Visual device including an ophthalmic lens having a partially cropped insertion rib, and method for preparing such lens
EP1993797A1 (en) Method for drilling an ophthalmic lens to obtain the desired shape and dimension of a hole to be drilled in said lens
EP2399709A1 (en) Process for the calculation and simulation of a peripheral mounting rib on the edge of a spectacle lens and bevelling process
FR2669265A2 (en) Method for the manufacture of an artificial optical lens, and corresponding artificial optical lens

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20050916

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL LT LV MK

DAX Request for extension of the european patent (deleted)
RIN1 Information on inventor provided before grant (corrected)

Inventor name: JOUARD, LUDOVIC

Inventor name: GUILLERMIN, LAURENTESSILOR INTERNATIONAL

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 602004033770

Country of ref document: DE

Owner name: ESSILOR INTERNATIONAL, FR

Free format text: FORMER OWNER: ESSILOR INTERNATIONAL (COMPAGNIE GENERALE D'OPTIQUE), CHARENTON-LE-PONT, FR

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: FRENCH

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602004033770

Country of ref document: DE

Effective date: 20110929

REG Reference to a national code

Ref country code: NL

Ref legal event code: VDEP

Effective date: 20110803

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20111205

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 518621

Country of ref document: AT

Kind code of ref document: T

Effective date: 20110803

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20111104

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

REG Reference to a national code

Ref country code: IE

Ref legal event code: FD4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

26N No opposition filed

Effective date: 20120504

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602004033770

Country of ref document: DE

Effective date: 20120504

BERE Be: lapsed

Owner name: ESSILOR INTERNATIONAL (COMPAGNIE GENERALE D'OPTIQ

Effective date: 20120331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120331

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20120324

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120331

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120324

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120331

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120331

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20111114

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20111103

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110803

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120324

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040324

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 13

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 14

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 15

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 602004033770

Country of ref document: DE

Representative=s name: 24IP LAW GROUP SONNENBERG FORTMANN, DE

Ref country code: DE

Ref legal event code: R081

Ref document number: 602004033770

Country of ref document: DE

Owner name: ESSILOR INTERNATIONAL, FR

Free format text: FORMER OWNER: ESSILOR INTERNATIONAL (COMPAGNIE GENERALE D'OPTIQUE), CHARENTON-LE-PONT, FR

REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

Owner name: ESSILOR INTERNATIONAL, FR

Effective date: 20180601

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20190325

Year of fee payment: 16

Ref country code: DE

Payment date: 20190327

Year of fee payment: 16

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602004033770

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20201001

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20200331