Abstract:
A method for calculating a customized progressive addition surface S' ' ' of a progressive addition lens (PAL) made of a material having an optical index of n, the method, comprising at least the successive steps of : a) providing N initial progressive addition surfaces where N ≥ 1, b) calculating N intermediate surfaces S' k by flattening each initial progressive addition surfaces S k , c) calculating a transformed intermediate surface S' ', d) calculating the customized progressive addition surface S' ' ' by cambering the transformed intermediate surface S' '.
Abstract:
A method of calculating an optical system (OS) of an ophthalmic lens according to a given spectacle frame comprising the steps of : • providing geometrical data of the spectacle frame, • providing wearer data, • optimization of the optical system (OS) according to at least the criteria consisting of the geometrical data of the spectacle frame, the wearer data and at least one positioning data, so as to generate at least two optical surfaces (S1, S2).
Abstract:
The invention relates to a method for the optimisation determination of an ophthalmic lens that comprises the steps of : measuring parameters representative of the eye-head behaviour of the wearer; determining a central area on the lens having a diameter (D c ) that depends on the measured parameters representative of the eye-head behaviour; determining a peripheral area on the lens; optimising the lens when worn by the wearer by applying power and astigmatism target values in the central area and target values of a parameter different from the wearer's power in the peripheral area for given watching directions. The invention reduces the thickness of the lens and optimises the wearer's peripheral vision.
Abstract:
La lentille présente une puissance de réfringence prismatique horizontale qui varie progressivement le long de la méridienne principale de progression (MM') avec une addition de puissance prismatique horizontale supérieure à 2 dioptries prismatiques en valeur absolue, cette addition de puissance prismatique horizontale étant définie par la différence entre la puissance de réfringence prismatique horizontale au point de référence (L) de la zone de vision de loin et la puissance de réfringence prismatique horizontale au point (P') de projection du point de référence (P) de la zone de vision de près (VP) sur la verticale passant par le point de référence (L) de la zone de vision de loin.
Abstract:
The present invention relates to a method of and an apparatus for designing an optical lens surface for the manufacture of the optical lens, the method comprising the steps of providing a reference surface S ref , the reference surface S ref being defined by a plurality of surface points P i each surface point P i having a mean sphere Sph (P i ) and a cylinder CyI(P i ); providing at least one modifying surface layer SL mod (ξ 1 ,..., ξ N , x,y) the modifying surface layer SL mod being determined as a function of N adjustment parameters ξ 1 , ξ..., ξ N ; wherein N≥1 and the N adjustment parameters ξ 1 , ξ 4 ,..., ξ N are selected according to the desired optical properties of the optical target; combining the modifying surface layer SL mod with the reference surface S ref to obtain a target optical surface S tar (x,y) according to the expression: S tar (x,y) = S ref (x,y) + SL mod (ξ 1 ,..., ξ N , x,y); such that the value of surface parameter of at least one surface point P i at a first region of the reference surface S ref is modified without modifying a surface parameter of at least one surface point P i at a second region of the reference surface S ref , distanced from the first region.
Abstract:
Un procédé de détermination d'une surface complexe d'une lentille ophtalmique progressive comprend les étapes consistant à : choisir une surface complexe de départ présentant une méridienne principale de progression avec une addition de puissance entre un point de référence en vision de loin et un point de référence en vision de près; sélectionner une bande centrale (10) incluant la méridienne principale de progression; reproduire la bande centrale sélectionnée (10) de part et d'autre de la méridienne 10 principale de progression; construire la surface complexe de la lentille en reproduisant successivement des bandes sélectionnées vers la périphérie de la lentille. Ce procédé permet d'obtenir une lentille avec un astigmatisme, des déviations prismatiques et des distorsions réduits pour un confort accru du porteur.
Abstract:
The invention relates to a method of calculating an optical system (OS), the optical system (OS) being identified by a function (OF), the optical system (OS) comprising a first part (Fl) defined by a first equation (EFl) and a second part (F2) defined by a second equation (EF2), the method comprising: - a generating step (GEN), in which a virtual optical system (VOS) is used to generate a virtual function (VOF); - a modification step (MOD), in which the virtual function (VOF) is modified so as obtain the function (OF); - a calculation step (CAL), in which the second equation (EF2) is calculated from the function (OF), and the first equation (EFl). The invention relates also to a method of manufacturing an optical system (OS).
Abstract:
A method of generating a target surface (I) of an optical lens for the manufacture of the optical lens according to optical lens parameters (II), the method comprising: providing a set of L first surface difference data E(λ j ) each first surface difference data E(λ j ) corresponding to the surface difference between a pre-calculated surface (III) and an initial surface (IV), from which the target surface will be generated, according to the expression: (V) where λ j (j = 1,..., L ) correspond to the optical lens parameters of the pre-calculated optical lenses; providing a set of second surface difference data (VI) corresponding to the surface difference between the target optical surface (I) and the initial surface (VII) by linear interpolation of the first surface difference data E(λ j ) according to the expression: (VIII), where (IX) represents an interpolation coefficient; and; determining the target surface (I) by combining the second surface difference data (vi) and the initial surface(VII) according to the expression: (X).
Abstract:
Un procédé de découpe d'une pastille à appliquer sur un substrat courbe (20) comprend un calcul préalable de longueurs curvilignes (I 1 , I 2 , I 3 ,...) sur le substrat, entre un point de référence (O) et un bord périphérique (B) dudit substrat. Les longueurs calculées sont reportées sur un film plan destiné à constituer la pastille, puis la pastille est découpée en reliant des extrémités (C 1 , C 2 , C 3 ,...) des longueurs reportées. La pastille coïncide alors précisément avec le bord du substrat. Un tel procédé est particulièrement utile pour appliquer un film fonctionnel sur un verre de lunettes, lorsqu'un détourage du verre après que le film a été assemblé avec le verre dégraderait le film.
Abstract:
The invention relates to a lens with a horizontal prismatic refractive power which varies progressively along the principal meridian of progression (MM') with an addition of horizontal prismatic power greater than 2 prismatic dioptres in absolute terms. This addition of horizontal prismatic power is defined by the difference in power of horizontal prismatic refraction at a reference point (L) in the distant field of vision and the power of horizontal prismatic refraction at the point (P') of projection of the point of reference (P) in the near field of vision (VP) onto the vertical passing through the point of reference (L) of the distant field of vision.