Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
  • G02C7/00—Optical parts
  • G02C7/02—Lenses; Lens systems ; Methods of designing lenses
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B3/00—Simple or compound lenses
  • G02B3/02—Simple or compound lenses with non-spherical faces
  • G02B3/08—Simple or compound lenses with non-spherical faces with discontinuous faces, e.g. Fresnel lens
• • G—PHYSICS
  • G02—OPTICS
  • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
  • G02C2202/00—Generic optical aspects applicable to one or more of the subgroups of G02C7/00
  • G02C2202/16—Laminated or compound lenses
• • G—PHYSICS
  • G02—OPTICS
  • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
  • G02C2202/00—Generic optical aspects applicable to one or more of the subgroups of G02C7/00
  • G02C2202/20—Diffractive and Fresnel lenses or lens portions

Definitions

• the present invention relates to a patch for attachment to a face of an optical component to modify an optical power thereof. It also relates to an optical element and a pair of glasses that incorporate such a pellet, as well as a method of manufacturing the pellet. It may be useful to adapt the power of an optical component according to a particular use thereof. This may be the case, for example, to adapt a glass of sun protection glasses to the ametropia of a carrier of this glass.
• the power of an optical component refers to the vergence of this element, and is commonly expressed in diopters.
• the pellet includes a Fresnel lens which is formed of a series of Fresnel zones disposed one inside the other parallel to a smooth face of the pellet. These zones have jumps in height between two successive zones that are greater than five times an average wavelength of visible light, the jumps in height being measured in a direction perpendicular to the tangent of the smooth face.
• the pellet itself has an optical power which results from the refraction of the light rays on both sides of the pellet in each Fresnel zone. This optical power of the chip is added to that of the optical component to which it is applied.
• the use of a Fresnel lens shape reduces the thickness of the pad to achieve a fixed power change, compared to an additional lens that would be contiguous to the optical component.
• pellets have an initial planar shape, and must be curved when applied to the curved surface of an ophthalmic lens or lens.
• This deformation of the pellet at the moment of its application to the lens or to the ophthalmic lens creates distortions of an image formed through the lens or glass, once the lens or glass is provided with the wafer, as well as optical aberrations.
• Such defects are particularly troublesome for ophthalmic application, since an object then appears with variable deformation when viewed through different locations of the glass.
• the distortions of the image vary dynamically when the observed object moves in the field of view or when the wearer of the glass turns his head following the object of the gaze. These image distortions are very troublesome.
• these defects are all the more important as the optical power change provided by the chip is high.
• the existing pellets are designed to be applied to a glass by turning the face of the pellets opposite the glass which has the jumps in height.
• the smooth face of each pellet which is located on the side opposite to the jumps in height, allows adhesion of the pellet on the glass by capillarity or electrostatic effect.
• the face of the pellet which is exposed to soiling is then that which comprises jumps height. But it can not be cleaned simply because of its relief, and soil deposits that form in high jumps cause significant light diffusion. They also greatly degrade the quality of an image formed through the glass provided with the pellet, by locally deforming the wavefront light.
• a diffractive optical lens comprising a lower surface having an aspheric curve and an upper surface having a quasi-parabolic curve, said upper surface further including a plurality of diffractive streaks. These diffractive stripes are shaped in accordance with a Fresnel diffraction formula.
• the optical lenses as described are intended to be used as instrumental lenses, such as lenses that can be found in electronic devices such as cameras, projectors, or scanners. These optical lenses constitute diffractive optical elements. Such lenses can not be used in ophthalmic optics because of their design. Indeed a diffractive lens brings chromaticism, this one being more and more important with the corrective power which one creates at the level of the lens. As a result, the use of a diffractive lens as described in this patent application is not capable of providing a solution to the technical problem of the present invention.
• An object of the present invention is to provide an optical power modification patch that does not have the disadvantages mentioned above.
• the invention provides a pellet of the type described above, and which is intended to be fixed on a curved surface of an optical component to modify the power thereof.
• modifying means either the contribution of an optical power to an optical component not comprising power, or a variation of the optical power to an optical component already comprising its own optical power.
• the pellet has a generally convex shape in addition to the jumps in height that are present between the Fresnel zones.
• the smooth face of the pellet has an initial curvature which corresponds substantially to the shape of the curved surface of the optical component intended to receive said pellet.
• the face of the pellet which includes the jumps in height also has a mean curvature which also corresponds to said curved surface of the optical component. It is this face of the pellet which includes the jumps in height which is intended to be brought into contact with the curved surface of the optical component.
• An optical power modification patch according to the invention is therefore not flat, but has a generally convex shape, for example substantially spherical, in addition to jumps in height.
• the pellet With this initial curved shape, the pellet is only slightly deformed, or not deformed, when it is applied to the surface of an optical component which is itself substantially curved. The pellet then creates little or no image distortion, or optical aberration, when an object is observed through the optical component provided with the pellet.
• the comfort of use of the optical component is not degraded by the chip, even for a chip that makes a significant optical power change that may be greater than 30 diopters in absolute value at the level of the chip in itself. even.
• optical component means visors such as helmet visors and ophthalmic lenses.
• visors such as helmet visors and ophthalmic lenses.
• optical lenses means lenses adapted in particular to a spectacle frame or to a mask such as a ski mask or a diving mask, as well as masks whose function is to protect the eye and / or correcting the view, these lenses being chosen from afocal, unifocal, bifocal or progressive addition lenses.
• mask such as solar masks, is meant a lens consisting of a single piece and intended to be positioned in front of both eyes. Such ophthalmic lenses or visors may be optionally tinted.
• optical components within the meaning of the invention may optionally have one or more functions that do not provide the application of one or more coatings and may especially be chosen from photochromic, anti-reflective, anti-fouling, anti-shock and anti-scratch coatings. , polarizing and antistatic.
• the invention is particularly suitable for corrective or non-corrective ophthalmic lenses.
• the jumps in height between successive Fresnel zones are located on a generally convex face of the pellet.
• the face of the pellet which is exposed to soiling is that which is smooth. It can therefore be easily cleaned.
• the face of the pellet which includes the jumps in height is then protected from dirt by the lens against which it is applied.
• the modification of the optical power that is provided by the pellet is then permanent, and is not affected by dirt deposits.
• the average radius of curvature of the pellet is between 135 mm (millimeters) and 53 mm.
• Such a radius of curvature corresponds to the shape of the posterior face, or concave face, of many spectacle lenses.
• the jumps in height between successive Fresnel zones have substantially constant amplitudes within a circle of 10 mm radius surrounding the optical center of the patch.
• the face of the pellet which includes the jumps in height then has a constant height of reliefs in a central part of this face. This further contributes to ensuring that no image distortion or optical aberration is caused by the chip when it is applied against an optical component on the side of the jumps height.
• the invention also comprises a patch in which the jumps in height between successive Fresnel zones have substantially constant amplitudes over the entire surface of said patch.
• the invention thus comprises the different possible combinations between jumps of variable height between Fresnel zone and jump of constant height between constant Fresnel zone on all or part of the surface of the patch.
• the invention also relates to an optical element which comprises a basic optical component and a patch as described above, fixed on the component.
• the face of the pellet which has the jumps in height is turned towards the base component within the optical element, to protect this face against soiling.
• the pellet may be attached to the component by a layer of material having adhesive properties capable of providing permanent cohesion between said pellet and said optical component.
• the basic optical component may be an ophthalmic lens.
• an ophthalmic lens is tinted or partially reflective and optionally has optical properties capable of correcting an ametropia.
• the pellet is then little visible and does not reduce the aesthetics of a pair of glasses that includes the lens, when applied to the concave or posterior face of the lens.
• the invention also relates to a pair of spectacles which comprises minus a lens and a pellet as described above, which is fixed on the lens.
• the pellet is fixed on the posterior surface of the lens.
• Such a pair of spectacles may be of the type of ametropia corrective glasses, tinted or not, or glasses or non-corrective sun protection mask, in particular.
• the invention finally relates to a method of manufacturing an optical power modification pad as described above, from a thermoplastic material.
• FIG. 1a is a perspective view of a pellet according to the invention.
• FIG. 1b and 1c are respective sectional views of two pellets according to the invention
• FIG. 2a and 2b are sectional views of two ophthalmic lenses, adapted to be adapted to a pair of glasses, provided with pellets according to Figures 1b and 1c;
• FIG. 3 is a diagram illustrating variations in height jumps for a tablet according to the invention.
• FIG. 4 illustrates a convention for measuring a wetting angle;
• FIG. 5 schematically illustrates the principle of manufacture of a pellet according to the invention.
• a tablet 1 according to the invention has a generally domed shape, or cup.
• the pellet has a spherical cap shape, with an average radius of curvature which may be of the order of 66 mm (millimeters) for example. This radius of mean curvature is advantageously between 88 mm and 53 mm
• the pellet 1 constitutes a Fresnel lens: it is formed of a succession of Fresnel zones which are concentrically arranged contiguously, for example 100 to 200 zones. These zones, referenced 2 in the figures are coaxial crowns which are oriented and centered along an optical axis marked z. The z axis then passes through an optical center of the pellet, which is located thereon and is denoted by O.
• each Fresnel zone corresponds to a lens portion, and the thickness of the pellet 1 varies. continuously within this zone in a radial direction, denoted r, in a plane perpendicular to the z axis.
• one of the surfaces of the pellet 1 has a height jump parallel to the z axis, referenced 3. Its amplitude is noted ⁇ z. It is specified that the jumps in height 3 which are present between successive zones 2 are superimposed on the general shape of the pellet 1, this general shape being curved, possibly approximately spherical, according to the invention.
• the jumps of height 3 correspond to discontinuities in height of the convex face of the pellet 1, referenced Sl
• a Fresnel zone 2 has a radial dimension which is denoted ⁇ r, measured perpendicularly to the z axis.
• the concave face of the pellet 1, referenced S2 is then smooth, e denotes the average thickness of the pellet 1, between the faces S1 and S2. It is measured perpendicular to the S2 face.
• the thickness e is less than 2 mm and may be between 0.5 and 0.7 mm. The increase in weight of an optical element comprising the patch 1, which is due to the latter, is then limited.
• the Fresnel zones 2 are dimensioned so that the amplitudes ⁇ z of the jumps of height 3 are at least equal to five times one. average wavelength of visible light.
• the amplitudes of the jumps in height 3 can be between 5 microns (micrometers) and 250 microns. In this way, because of the short length of coherence of the light Naturally, no interference is perceptible that would occur between portions of a light beam that pass through different areas.
• the pellet 1 has a purely refractive optical effect, which is related to the shape of the surfaces S1 and S2 in each zone 2, and produces no visible diffractive effect.
• the amplitudes of the jumps in height 3 between successive Fresnel zones may be variable over at least a portion of the surface of the patch while maintaining a substantially spherical profile on the surface (S1). In this case, the amplitude ⁇ z is greater at the periphery of the pellet than in its central zone.
• the amplitude of these jumps can be between 5 microns and 250 microns; in the case where the jumps in height between successive Fresnel zones are constant over the entire surface (S1) then they may be between 5 microns and 100 microns; and in the case where the jumps in height between successive Fresnel zones have substantially constant amplitudes within a circle (C) of 10 mm radius surrounding the optical center of the patch (O), the amplitude in of a circle (C) may be between 5 ⁇ m and 50 ⁇ m, and the variable amplitude of the height jumps outside this circle (C) to a peripheral part of the lens may be between 5 ⁇ m and 250 ⁇ m.
• the radial dimension ⁇ r of each zone 2 then depends on the optical power of the pellet 1 and the amplitude ⁇ z of the height jumps 3. In the preceding conditions, and for an optical power of the pellet 1 less than 12 diopters, ⁇ r may be between 10 ⁇ m and 2 mm.
• the pellet 1 may have a positive or negative vergence, depending on the direction of variation of its thickness in the direction r, within each Fresnel zone 2.
• FIGS. 1b and 1c respectively correspond to a convergent or divergent pellet .
• the variation of the thickness of the pellet inside each zone 2 may be, in particular, a quadratic function of r.
• FIGS. 2a and 2b show two ophthalmic lenses that are adaptable to a pair of spectacles that are provided, on their posterior faces SO, or concave faces, pellets according to Figures 1b and 1c, respectively. It is understood that each of these pellets can be used in the same way with the lens of the other figure, and that the combinations illustrated are only taken as examples.
• the lens of FIG. 2a, referenced 10 may be a sun protection lens with zero optical power, since it has two parallel faces.
• the pellet 1 then gives it a non-zero power, which makes it possible to correct an ametropic defect of a wearer of the lens. In this way, the patch 1 makes it possible to adapt any sun protection lens to a carrier having an ametropia.
• the pair of spectacles comprising such a lens 10 may then be chosen by the wearer according to his aesthetics, his color, or the shape of the associated frame.
• the lens of Figure 2b, referenced 11, corresponds to a correction of myopia, since it is thinner at its center than at its periphery.
• the patch 1 then makes it possible to adapt the strength of the correction as a function of the degree of myopia of the wearer.
• the pellet 1 is placed on the glass 11 so as to superpose the respective optical axes of the glass and the pellet. An identical function is obtained with a corrective lens of hyperopia.
• the pellet 1 is applied to the posterior surface SO of the lens 10 or 11, which is smooth. This operation can be done directly by the practitioner on the pair of glasses in which the lens is mounted on the frame chosen by the wearer.
• the jumps of height 3 preferably have substantially constant amplitudes within a circle C of radius R c surrounding the center O. In this way, the pellet 1 can be applied more easily against the surface SO of the lens, at least in a central zone of the pellet, inside the circle C.
• FIG. 3 represents an example of variation of the amplitudes ⁇ z of the jumps of height 3 in the radial direction r.
• the amplitudes ⁇ z of the jumps 3 are constant and the radial dimension ⁇ r of the zones 2 decreases for zones 2 of larger and larger.
• the jumps of height 3 may have amplitudes ⁇ z which increase, in particular to avoid making areas 2 which would have radial dimensions ⁇ r very short.
• R c may be equal to 10 mm, for example, and the amplitudes ⁇ z of the jumps of height 3 may be equal to 40 ⁇ m inside circle C.
• the wafer 1 is adhered to the SO face of the lens 10 or 11, with a layer of adhesive material 20 disposed between the wafer 1 and the lens.
• the adhesive material 20 which is used advantageously has, in the liquid state, a wetting angle on the pellet 1 which is less than 90 °.
• FIG. 4 illustrates the convention adopted here for measuring the wetting angle ⁇ of the adhesive material 20 on the material of the wafer 1. Under these conditions, the adhesive material 20 penetrates to the bottom of the jumps of height 3 without retaining of air bubble.
• Several types of adhesive material may be used, in particular a radiation-polymerizable or thermal-curing adhesive or latex-type adhesive. Particularly successful embodiments of the invention have been obtained with an acrylate-based glue and polymerizable by UV irradiation.
• Respective values substantially equal to 1, 59 and 1, 50 for the material of the pellet 1 and for the adhesive material 20 have made it possible to obtain optical power changes greater than 6 diopters, in absolute values, or even greater than 12 diopters .
• the lens 10 or 11 may be made of any material commonly used in the ophthalmic industry, to correct an ametropia or to achieve sun protection.
• the material of the ophthalmic lens can thus be of mineral or organic type. As an indication but not limiting, mention may be made as organic material that can be used in the context of the invention the materials conventionally used in optics and ophthalmia.
• substrates of the polycarbonate type are suitable; polyamide; polyimides; polysulfones; copolymers of poly (ethylene terephthalate) and polycarbonate; polyolefins, especially polynorbomene; polymers and copolymers of diethylene glycol bis (allyl carbonate); (meth) acrylic polymers and copolymers, especially polymers and (meth) acrylic copolymers derived from bisphenol-A; thio (meth) acrylic polymers and copolymers; urethane and thiourethane polymers and copolymers; Epoxy polymers and copolymers and polymers and copolymers episulfide.
• a pellet according to the invention may advantageously be produced by injection of a transparent thermoplastic material, for example based on polycarbonate, into an injection mold.
• the mold is fed, in a manner known per se, by a device for compressing and injecting the material, which comprises a compression screw and a heating device.
• Figure 5 schematically illustrates such a mold 100.
• Two inserts, referenced 101 and 102 are placed in the mold.
• the insert 101 defines the face S1 of the pellet 1 which comprises the jumps in height, and the insert 102 defines the smooth face S2. They are arranged vis-à-vis and separated by a space 103 which corresponds to the pellet 1.
• the thermoplastic material is then injected into the mold 100 by an injection nozzle 104, so as to fill the space 103.
• the pellet 1 can be recovered.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Health & Medical Sciences (AREA)
• Ophthalmology & Optometry (AREA)
• General Health & Medical Sciences (AREA)
• Eyeglasses (AREA)
• Diffracting Gratings Or Hologram Optical Elements (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=36952016

Family Applications (1)

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Citations (4)

Family Cites Families (18)

• 2006
  • 2006-06-07 FR FR0605059A patent/FR2902200B1/fr active Active
• 2007
  • 2007-05-29 US US12/303,630 patent/US8210677B2/en active Active
  • 2007-05-29 WO PCT/FR2007/051340 patent/WO2007141440A1/fr not_active Ceased
  • 2007-05-29 BR BRPI0711960-7A patent/BRPI0711960B1/pt active IP Right Grant
  • 2007-05-29 CN CN2007800213186A patent/CN101467076B/zh active Active
  • 2007-05-29 JP JP2009513733A patent/JP2009540347A/ja active Pending
  • 2007-05-29 EP EP07766108A patent/EP2024765A1/de not_active Withdrawn

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