EP3943240A1 - Appareil et procédé de centrage - Google Patents

Appareil et procédé de centrage Download PDF

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Publication number
EP3943240A1
EP3943240A1 EP20305854.0A EP20305854A EP3943240A1 EP 3943240 A1 EP3943240 A1 EP 3943240A1 EP 20305854 A EP20305854 A EP 20305854A EP 3943240 A1 EP3943240 A1 EP 3943240A1
Authority
EP
European Patent Office
Prior art keywords
centering
lens
outlines
ophthalmic lens
markings
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.)
Pending
Application number
EP20305854.0A
Other languages
German (de)
English (en)
Inventor
Laurent Roussel
Hugues AMEURLAIN
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
Priority to EP20305854.0A priority Critical patent/EP3943240A1/fr
Priority to US18/015,494 priority patent/US20230249308A1/en
Priority to CN202180061020.8A priority patent/CN116194249A/zh
Priority to BR112023000250A priority patent/BR112023000250A2/pt
Priority to PCT/EP2021/061901 priority patent/WO2022017657A1/fr
Priority to CN202121380370.4U priority patent/CN214846114U/zh
Publication of EP3943240A1 publication Critical patent/EP3943240A1/fr
Pending legal-status Critical Current

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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
    • B24B13/00—Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories therefor
    • B24B13/005—Blocking means, chucks or the like; Alignment devices
    • B24B13/0055—Positioning of lenses; Marking of lenses
    • 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
    • B24B9/144—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 the spectacles being used as a template

Definitions

  • the present invention generally relates to the field of eyeglasses.
  • a centering apparatus including:
  • the technical part of the work of an optician which consists in mounting a pair of ophthalmic lenses in a spectacle frame selected by a customer, may be split into four main operations:
  • centering and blocking operations are more particularly of interest.
  • apparatuses are generally configured in the same way, with means for holding the ophthalmic lens, optical means for centering the ophthalmic lens, and blocking means for depositing the blocking accessory on the lens.
  • the optical centering means include a camera and a screen on which the optician may observe the lens superposed on a centering reticle, thereby allowing him to move the lens with respect to this reticle so as to center it correctly.
  • the blocking means for their part include an arm that is stationary and that supports the blocking accessory.
  • the lens support is movable along an axis parallel to the axis of the camera, so that the optician can press the lens and its support towards the blocking accessory when the lens is centered.
  • the position of the blocking accessory on the lens then depends on the position of the lens with respect to the reticle.
  • This reticle has usually a cross shape, that is perfectly adapted when the lens markings comprise a point or a cross to be centered on the reticle.
  • lens markings have sometimes shapes that make the centering operation difficult to implement.
  • lens markings can be round micro-engravings, very numerous, and distributed along concentric circles.
  • the present invention provides a centering apparatus as disclosed in the introduction, having a reticle (named “centering target”) that comprises two coaxial and parallel outlines.
  • These outlines have a shape that depends on the shape of the lens markings.
  • the lens markings are formed by round micro-engravings, very numerous, and distributed along concentric circles, these outlines are circular and designed to be placed on either sides of one of the concentric circles, which enables to center more accurately the lens relative to the reticle.
  • a reticle composed of at least two outlines could be applied to lenses whose micro-engravings have (or are distributed along a contour having) a round shape, a square shape, or at least an enclosing shape (not a cross for example).
  • the invention also applies to a method for centering an ophthalmic lens, comprising steps of:
  • the ophthalmic lens comprises centering markings and the method comprises, before or during the step of manually modifying the position of the ophthalmic lens, a step of adjusting the distance between the two outlines as a function of the geometry of said centering markings.
  • these two steps of manually modifying the position of the ophthalmic lens and of adjusting the distance between the two outlines are performed simultaneously by the optician.
  • the optician shall first position roughly the lens so that it could be possible to adapt the scale of the outlines to the size of the centering marks.
  • the optician can use them to position the lens more accurately.
  • the centering markings comprising patterns distributed along a contour centered on a point, the distance between said two outlines is adjusted so as to be comprised between once and twice the pattern width, said width being radially measured relative to said point.
  • the centering markings comprise patterns distributed along concentric circles, and each outline has a circular shape.
  • Figure 1 shows an example of centering-blocking apparatus 1.
  • Such an apparatus is used by an optician to prepare an ophthalmic lens for edging to a given outline, with a view to mounting this ophthalmic lens in a spectacle frame selected by a customer.
  • This apparatus is generally used after the optician has acquired the shape of the outline C1 to which the lens must be edged (see Fig.2 ). This apparatus is then employed to carry out the operations of centering and blocking the ophthalmic lens.
  • the objective of the centering operation is to locate the frame of reference of the ophthalmic lens, and to determine the position that the aforementioned outline must occupy in this frame of reference so that the lens, once edged to this outline then mounted in the spectacle frame, is suitably centered facing the corresponding eye of the customer (in order to fulfil as best as possible the optical function for which it was designed).
  • the objective of the blocking operation is to place an accessory (called the "blocking accessory”) on the ophthalmic lens, thereby making it easier to provide a stable coordinate system allowing the position of the frame of reference of the lens to be located after it has been transported from the centering-blocking apparatus 1 to an edging apparatus.
  • an accessory called the "blocking accessory”
  • the ophthalmic lens 100 to be edged is shown in Figure 2 .
  • This lens has two optical faces (namely a convex front face and a concave back face) and an edge, the shape of which is initially circular.
  • the shapes of the front and back faces of this ophthalmic lens 100 are designed such that the lens has optical characteristics allowing defects in the vision of the customer to be corrected.
  • the ophthalmic lens 100 includes a first optical correction for providing correct vision to the wearer at a determined distance, and a second optical correction for changing the natural evolution of Myopia.
  • the first optical correction consists, in our example, in a spherical power for providing correct far vision to the wearer (for looking at objects situated at more than 6 meters).
  • This first optical correction could also include a cylindrical and/or a prismatic power.
  • the optical center of the lens is defined as the point of the lens where the light rays are not deviated when they pass through the lens.
  • the centering point P1 of the ophthalmic lens 100 that is the point where the blocking accessory has to be deposited, is formed by this optical center.
  • the centering point P1 is formed by the geometric center (called “boxing center”) of a virtual rectangular box circumscribing the outline C1 along which the lens will be edged.
  • the centering and blocking apparatus 1 shall inform the edging apparatus in which point the blocking accessory is positioned.
  • the second optical correction provides an additional optical feature. This correction is specifically designed to limit or to stop the evolution of myopia.
  • the ophthalmic lens 100 contains to this end microlenses.
  • Such an ophthalmic lens is described in document WO2019166654 .
  • the ophthalmic lens 100 is provided with centering markings 110 allowing its frame of reference to be located.
  • markings may take the form of temporary marks printed in ink and/or permanent marks engraved into the lens (micro-engravings are spoken of).
  • Provisional markings generally allow the optical frame of reference of the lens to be suitably located prior to its mounting in the spectacle frame whereas permanent markings allow the nature and characteristics of the ophthalmic lens to be identified and, after the provisional markings have been removed, the exact location of said lens to be identified or reestablished.
  • the ophthalmic lens 100 has only permanent markings for determining the centering point P1 of the lens.
  • these micro-engraved markings 110 are each round, they are very numerous, and they are distributed along concentric circles about the centering point P1 of the ophthalmic lens 100.
  • the lens comprises more than three circles. Each circle comprises more than ten markings 110.
  • the markings of a single circle have all the same diameter D2. Here, all the markings have the same diameter D2. This diameter is lower than 1 mm.
  • these centering markings 110 are formed by the contours of the microlenses that are engraved in one of the optical faces of the lens to fulfill the second optical correction.
  • the ophthalmic lens 100 is intended to be centered and blocked manually.
  • the centering-blocking apparatus 1 includes for this purpose at least:
  • This centering-blocking apparatus may have several shapes.
  • the holder could be fixedly mounted on the chassis and the blocking means could include a movable arm that is manually maneuverable so that the optician can force the arm to deposit the blocking accessory on the lens.
  • the blocking means 30 are fixedly mounted on the chassis 10, and it is the holder 20 that is movably mounted on the chassis 10.
  • the represented centering-blocking apparatus 1 can now be briefly described.
  • the chassis 10 includes a dome 11.
  • This dome 11 has a sidewall the top face of which is apertured with a large circular aperture centered on a main axis A1 that here is vertical. It also includes a bottom that lies in a horizontal plane and that closes the back of the sidewall. It lastly includes, at mid-height, a false bottom 14.
  • This false bottom 14 is visible through the large circular aperture 12. It has in its center a circular hole centered on the main axis A1.
  • the blocking means 30 (which are designed to hold the blocking accessory 200) includes a vertical shaft that is centered on the main axis A1. This vertical shaft has a lower end that is secured to the chassis and a free upper end for accommodating the blocking accessory 200.
  • the holder 20 is a transparent and vertical tube mounted on the chassis 10 so as to be able to slide along the main axis A1.
  • the upper end 22 of the holder 20 is circular and extends in a horizontal plane, such that it is suitable to support the ophthalmic lens 100.
  • This holder 20 is more precisely mounted so as to be movable between:
  • An elastic element suitable for automatically returning the holder 20 to the centering position, is provided inside the dome 11.
  • the holder could comprise three protruding pins forming a tripod for accommodating the ophthalmic lens.
  • the centering means 40 are intended to observe the ophthalmic lens 100 along a viewing axis A2 that is parallel (here coincident) with the main axis A1.
  • these centering means 40 include here means 50 for illuminating the ophthalmic lens 100 and means 60 for viewing the ophthalmic lens 100 illuminated by the illuminating means 50.
  • the illuminating means 50 are distributed all around the holder 20, so as to generate light of grazing incidence on the optical face of the lens that is placed on the holder 20 (here on the convex front face, in which the centering markings 110 are engraved).
  • These illuminating means 50 in this instance include a plurality of light-emitting diodes that are regularly distributed around the holder 20.
  • the viewing means 60 comprise a mirror 63 that is inclined at 45° with respect to the main axis A1 and that allows the image of the ophthalmic lens 100 to be redirected toward the objective 61 of a digital video camera 62.
  • This mirror 63 allows the centering-blocking apparatus 1 to be made more compact.
  • the digital video camera 62 is then designed to acquire an image of the ophthalmic lens 100 and to transmit it to a viewing screen 70 that is oriented toward the face of the optician.
  • This viewing screen 70 may be of any kind (for instance LCD, TFT). It is preferably mounted onto the chassis 10 but it could be remoted from it.
  • the optician may observe in real-time on this viewing screen 70 the image of the ophthalmic lens 100, in which the centering markings 110 provided on the lens clearly appear.
  • the centering-blocking apparatus also comprises a processing unit programmed to help the optician in centering the ophthalmic lens 100.
  • the processing unit comprises a central processing unit (CPU), a memory and input/output components.
  • CPU central processing unit
  • the processing unit stores information used in the process described below. It stores in particular a computer application, consisting of computer programs comprising instructions, the execution of which allowing the implementation by the processing unit of the method described below.
  • This processing unit is connected to the viewing screen 70 so as to display a reticle superimposed to the images acquired by the camera 62.
  • a reticle is defined as a centering target or as a fixed coordinate system that indicates the position of the blocking accessory 200.
  • this reticle comprises two coaxial and parallel outlines 150, 151.
  • Each outline is preferably a line (a curve or a succession of segments) extending along a closed contour.
  • the outer outline 151 is the image of the inner outline 150 after a homothety.
  • each outline 150, 151 here has a circular shape.
  • each outline 150, 151 would have a square shape.
  • These outlines 150, 151 are displayed on the viewing screen 70 in the form of solid lines, but they could be displayed in the form of dotted lines or dashed lines.
  • the outlines have a size that cannot be changed. But in a preferred embodiment, the size of at least one of the outlines 150, 151 is modifiable. Here the size of both outlines are modifiable.
  • the size of the centering markings 110 displayed on the viewing screen 70 can vary because of scale modifications due to the lens power; so, depending on the lens spherical power, the distance between the outlines can change.
  • lenses of different brands may show centering markings having different sizes, that is why it is advantageous to enable the size of the outlines to be scalable.
  • the radius R1 of the inner outline 150 is adjustable and the distance D1 between the two outlines 150, 151 is also modifiable.
  • the two outlines 150, 151 can be sized so that:
  • the distance D1 between the two outlines 150, 151 has to be adjusted so as to be comprised between once and twice the diameter of the engraved microlenses.
  • the optician is sure to have well centered the lens relative to the blocking accessory 200.
  • the apparatus 1 comprises an HMI (Human-Machine Interface) enabling the optician to manually modify the sizes of the outlines 150, 151 displayed on the viewing screen 70.
  • HMI Human-Machine Interface
  • This HMI can be formed by the screen if the latter is a touch screen.
  • two buttons associated to each outline are displayed, one for increasing the size of the associated outline and the second to decrease its size.
  • processing means are programmed to:
  • processing means are programmed to determine in a first step, the shape and the position of each centering marking 110.
  • a cross-shape reticle is displayed on the screen.
  • the exact shape of this reticle depends on the shape of the centering markings. In other words, the shape of the reticle depends on the lens kind:
  • the processing means determine the shape of the detected closed contour (here, this shape is circular). Then, they determine the mean diameter of one of the detected circles along which markings are distributed, and the diameters of these markings. Finally, they display on the screen two outlines 150, 151 adapted to the shapes of the centering markings.
  • the processing means are programmed to propose a reticle shape that is adapted to the family of the current lens and that is selected among six different shapes.
  • the centering-blocking apparatus 1 is used by the optician in the following way.
  • the optician loads a blocking accessory 200 on the vertical shaft.
  • the optician deposits the ophthalmic lens 100 on the upper end 22 of the holder 20, in such a way that the convex front face of the lens bears against this holder 20.
  • the camera 60 acquires images of the lens and these images are displayed on the viewing screen 70. These images are displayed together with the two outlines 150, 151.
  • the sizes and shapes of the two outlines 150, 151 are automatically modified to be adapted to the shape of the centering markings 110.
  • the optician manually moves the ophthalmic lens transversely, i.e. by sliding it over the holder 20, until the ophthalmic lens 100 is placed on the axis of the blocking accessory 200.
  • the optician observes the images of the ophthalmic lens 100 on the viewing screen 70, which images are displayed in superposition with the outlines 150, 151.
  • the optician then seeks in this step to place the two outlines 150, 151 on each side of a single circle of centering markings 110.
  • the sizes of the two outlines can be manually modified by the optician in order to achieve this aim.
  • the optician presses the ophthalmic lens 100 downward, while taking care not to move it transversely, so as to lower the holder 20.
  • This operation allows the lens to bear against a double-sided self-adhesive provided on the blocking accessory 200. In this way, the latter automatically bonds to the lens, in a desired position (with a precision better than half a millimeter).
  • This invention also applies to an automatic blocking system (having a motorized arm that can deposit the blocking accessory to a specific point of the lens and having centering means helping the optician with the camera's help to manually position the lens taking into account this blocking point).
  • the holder could take a different form from that shown in the figures. It could thus take the form of a tripod mounted so as to be able to slide on the chassis in a plane orthogonal to the main axis A1.
  • the centering and blocking apparatus may operate automatically for centering and blocking the lens (without the help of the optician).
  • the use of two outlines enables the centering of the lens by the processing means to be more accurate.
EP20305854.0A 2020-07-24 2020-07-24 Appareil et procédé de centrage Pending EP3943240A1 (fr)

Priority Applications (6)

Application Number Priority Date Filing Date Title
EP20305854.0A EP3943240A1 (fr) 2020-07-24 2020-07-24 Appareil et procédé de centrage
US18/015,494 US20230249308A1 (en) 2020-07-24 2021-05-05 Centering apparatus and process
CN202180061020.8A CN116194249A (zh) 2020-07-24 2021-05-05 定心设备和方法
BR112023000250A BR112023000250A2 (pt) 2020-07-24 2021-05-05 Aparelho e processo de centragem
PCT/EP2021/061901 WO2022017657A1 (fr) 2020-07-24 2021-05-05 Appareil et procédé de centrage
CN202121380370.4U CN214846114U (zh) 2020-07-24 2021-06-21 定心设备

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP20305854.0A EP3943240A1 (fr) 2020-07-24 2020-07-24 Appareil et procédé de centrage

Publications (1)

Publication Number Publication Date
EP3943240A1 true EP3943240A1 (fr) 2022-01-26

Family

ID=72046812

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20305854.0A Pending EP3943240A1 (fr) 2020-07-24 2020-07-24 Appareil et procédé de centrage

Country Status (5)

Country Link
US (1) US20230249308A1 (fr)
EP (1) EP3943240A1 (fr)
CN (2) CN116194249A (fr)
BR (1) BR112023000250A2 (fr)
WO (1) WO2022017657A1 (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1149664A2 (fr) * 2000-04-28 2001-10-31 Nidek Co., Ltd. Dispositif de pose de ventouse
US20020026262A1 (en) * 2000-08-30 2002-02-28 Kabushiki Kaisha Topcon Lens layout setting apparatus for lens grinding process and display apparatus for the same
JP2011161556A (ja) * 2010-02-08 2011-08-25 Topcon Corp 加工可否判定装置
US9645043B2 (en) * 2012-12-21 2017-05-09 Essilor International (Compagnie Generale D'optique) Method for checking the compliance of an optical characteristic of an ophthalmic lens and associated device
US20170163857A1 (en) * 2014-06-23 2017-06-08 Essilor International (Compagnie Générale d'Optique) Ophthalmic lens centring-blocking apparatus
WO2019166654A1 (fr) 2018-03-01 2019-09-06 Essilor International Élément de lentille

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1149664A2 (fr) * 2000-04-28 2001-10-31 Nidek Co., Ltd. Dispositif de pose de ventouse
US20020026262A1 (en) * 2000-08-30 2002-02-28 Kabushiki Kaisha Topcon Lens layout setting apparatus for lens grinding process and display apparatus for the same
JP2011161556A (ja) * 2010-02-08 2011-08-25 Topcon Corp 加工可否判定装置
US9645043B2 (en) * 2012-12-21 2017-05-09 Essilor International (Compagnie Generale D'optique) Method for checking the compliance of an optical characteristic of an ophthalmic lens and associated device
US20170163857A1 (en) * 2014-06-23 2017-06-08 Essilor International (Compagnie Générale d'Optique) Ophthalmic lens centring-blocking apparatus
WO2019166654A1 (fr) 2018-03-01 2019-09-06 Essilor International Élément de lentille

Also Published As

Publication number Publication date
WO2022017657A1 (fr) 2022-01-27
US20230249308A1 (en) 2023-08-10
BR112023000250A2 (pt) 2023-01-31
CN116194249A (zh) 2023-05-30
CN214846114U (zh) 2021-11-23

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