Device for capturing a standardized image of a spectacle lens and method for creating a digital file representative of the outline of an ophthalmic lens

Abstract

The invention relates to a device (10) for capturing a standardized image of a spectacle lens, comprising: - a housing (11) comprising a flat surface (14) configured to support an image capture means, the flat surface being provided with an opening having dimensions corresponding to the dimensions of an objective lens of the image capture means, - a base (12), which can be removed from the housing, comprising a flat surface (13): - configured to be positioned inside the housing, parallel to the flat surface of the housing, and - comprising at least one two-dimensional barcode, configured to identify image capture parameters dependent on the image capture means, and - comprising a catadioptric coating.

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION: STANDARDIZED PHOTOGRAPHIC DEVICE FOR AN EYEGLASS LENS AND METHOD FOR CREATING A DIGITAL FILE REPRESENTATIVE OF THE CONTOUR OF AN EYEGLASS LENS

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] The present invention relates to a device for standardized image capture of a spectacle lens and a method for creating a digital file representing the contour of a spectacle lens. The present invention is applicable to the field of eyewear, and more specifically to generating a file compatible with the tools used by an optician (for example, in the standard ORNA format).

[0005] STATE OF THE ART

[0006] Historically, the geometric shape of optical lenses for spectacles was determined based on a pre-existing frame (see, for example, US patent 5139373 by Gerber Optical).

[0007] Since the advent of electromechanical tracing / sensors more than fifty years ago, as described in US patent 355739, opticians have been able to automatically trace the shape of a lens from a frame. An evolution of this process has involved recording the data digitally on a computer, as described, for example, in US patent 5139373.

[0008] Another development in this process involved allowing the use of a different lens as a reference shape (for example, a "demonstration lens" provided by the frame manufacturer) to determine the dimensions and shape of the lens. Such a process is described, for example, in patent application FR2854268 A. In this latter process, it is the shadow of the lens projected onto a frosted surface that is measured.

[0009] Another development in methods for determining the geometric parameters of glass has involved using specially developed optical instruments, arranged and calibrated to work together. For example, a camera other than the one specified by the manufacturer cannot be used, and the same applies to the lighting and other components involved. Such a device is illustrated in document US9743833.

[0010] The prior art indicates that geometric measurements of the shape and dimensions of a glass can be performed:

[0011] - either by an electromechanical process which has the disadvantage of a significant measurement time (several minutes) due to the motorized movement of mechanical elements,

[0012] - either by an optical process which has the disadvantage of inseparably coupling, in a monolithic configuration: a fixed camera, a mechanical support, a lighting device and software designed to operate together in an all-in-one configuration. SUMMARY OF THE INVENTION

[0013] The present invention aims to overcome all or part of these drawbacks. The method and device of the present invention are designed to determine the shape and dimensions of a spectacle lens outline in order to generate a file compatible with the tools used by an optician (for example, in the standard ORNA format). This file can then serve as input for software enabling the 3D modeling of a frame adapted to the lens for 3D printing of this frame. The goal here is to extract the geometric (shape, dimensions) and non-optical (refractive index, focal length, correction, etc.) parameters of a spectacle lens.

[0014] The present invention makes it possible in particular to determine the shape and dimensions of an optical lens for glasses without a pre-existing frame in order to create a frame from the optical lenses.

[0015] BRIEF DESCRIPTION OF THE FIGURES

[0016] Other advantages, purposes and particular features of the invention will become apparent from the following non-limiting description of at least one particular embodiment of the device and method of the present invention, with reference to the accompanying drawings, in which:

[0017] Figure 1 schematically represents, in side view, a first particular embodiment of the device that is the subject of the present invention,

[0018] Figure 2 schematically represents, in top view, the casing of the first embodiment of the present invention,

[0019] Figure 3 schematically represents, in top view, the base of the first embodiment of the present invention,

[0020] Figure 4 schematically represents, in the form of a flowchart, a first embodiment of a process that is the subject of the present invention,

[0021] Figure 5 schematically represents a particular embodiment of a device that is the subject of the invention.

[0022] Figure 6 represents a radial section of a glass frame circle,

[0023] Figure 7 represents a spectacle lens, viewed perpendicular to its optical axis. Figure 8 represents a spectacle frame adapted to receive and retain the lens illustrated in Figure 2.

[0024] Figure 9 represents, in the form of a flowchart, the steps of a particular embodiment of the process which is the subject of the invention.

[0025] DESCRIPTION OF IMPLEMENTATION METHODS

[0026] This description is not exhaustive, as each feature of one embodiment can advantageously be combined with any other feature of any other embodiment. The term "and / or," as used in this document and in the claims, shall be understood as meaning "one or the other or both" of the elements thus combined, i.e., elements that are present conjunctively in some cases and disjunctively in others. Multiple elements listed with "and / or" shall be interpreted similarly, i.e., "one or more" of the elements thus combined. Other elements may optionally be present, other than those specifically identified by the "and / or" clause, whether or not they are related to those specifically identified elements.Thus, by way of non-limiting example, a reference to "A and / or B", when used in conjunction with an open language such as "including", may refer, in one embodiment, to A only (possibly including elements other than B); in another embodiment, to B only (possibly including elements other than A); in yet another embodiment, to A and B (possibly including other elements); etc.

[0027] As used herein in the description and in the claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" should be interpreted as inclusive, meaning the inclusion of at least one, but also more than one, of a number or list of items, and optionally, additional unlisted items. Only terms explicitly stating the contrary, such as "only one of" or "exactly one of," or, when used in the claims, "consisting of," refer to the inclusion of only one item from a number or list of items.

[0028] As used in this description and in the claims, the expression "at least one," with reference to a list of one or more elements, should be understood as meaning at least one element chosen from one or more elements in the list of elements, but not necessarily including at least one of each element specifically listed in the list of elements and not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements to which the expression "at least one" refers, whether or not they are related to those specifically identified elements.Thus, by way of non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") may refer, in one embodiment, to at least one, possibly including more than one, A, without B present (and possibly including elements other than B); in another embodiment, to at least one, possibly including more than one, B, without A present (and possibly including elements other than A); in yet another embodiment, to at least one, possibly including more than one, A, and at least one, possibly including more than one, B (and possibly including other elements); etc.

[0029] In the claims, as well as in the description below, all transitive expressions such as "comprising", "including", "carrying", "having", "containing", "implying", "holding", "composed of", and others, shall be understood as open, that is, as meaning "including, but not limited to". Only the transitive expressions "consisting of" and "consisting essentially of" shall be understood as closed or semi-closed transitive expressions, respectively.

[0030] It should be noted from the outset that the figures are not to scale.

[0031] Figures 1, 2 and 3 show a device 10 for taking a standardized photograph of a spectacle lens 20 which comprises:

[0032] - a housing 11 comprising a flat surface 14 configured to support an image capture means 30, the flat surface 14 being provided with an aperture 15 of dimensions corresponding to the dimensions of a lens 31 of the image capture means 30,

[0033] - a base 12, removable from the housing 11, comprising a flat surface 13:

[0034] - configured to be positioned inside the housing 11, parallel to the flat surface 14 of the housing 11, and

[0035] - comprising at least one two-dimensional barcode, 17, 18, configured to identify shooting parameters dependent on the image capture means 30 and

[0036] - comprising a catadioptric coating 16.

[0037] The housing 11 is preferably of the form of a perforated parallelepiped, one face of which is entirely perforated to receive the base 12. The opposite face 14 has the opening 15. Such a shape allows the base 12 to be placed on a flat surface of a piece of furniture, for example, and then the image capture means 30 to be placed on the opposite face 14 by positioning the lens 31 opposite the opening 15 to capture an image of the glass 20 placed on the catadioptric coating 16 of the base 12.

[0038] In variants, the housing 11 can have any shape known to a person skilled in the art as long as the base 12 has a flat surface 13 parallel to the flat surface 14 of the housing 11.

[0039] The housing 11 can be made by the optician using a 3D printer or any other machining process.

[0040] Preferably, the opening 15 is rectangular in shape. In other embodiments, the opening may have any shape known to a person skilled in the art.

[0041] The aperture is preferably centered with respect to the edges of the flat surface 14. Preferably, the aperture is of dimensions corresponding to the dimensions of average lenses of digital cameras integrated into mobile phones, for example into intelliphones (“Smartphones” in English), or into digital tablets.

[0042] The distance between the flat surface 13 of the base 12, when the base is assembled to the housing 11, and the flat surface 14 of the housing 11 is called "height". When the housing 11 is parallelepiped in shape, the dimension of the longest side of the flat surface 14 is called "length" and the dimension of the shortest side of the flat surface 14 is called "width".

[0043] For example, the parallelepiped-shaped box 11 has a length of 162 mm, a width of 117 mm, and a height of 190 mm. The "thickness" is the dimension of the solid body of the cross-section of the faces of the box 11. The thickness is, for example, 5 mm. The mass of such a box 11 is, for example, 300 g.

[0044] Preferably, the housing 11 and the base 12 are made of material that is at least partially opaque.

[0045] For example, the color and thickness of the housing 11 and the base 12 are configured to: - be sufficiently opaque to external light to require the user to activate a light source, for example a flash, from the image capture means 30, to take the picture and

[0046] - transparent to outside light to allow maximum contrast at the level of each two-dimensional barcode, 17 and 18.

[0047] Preferably, the case 11 and the base 12 are made of polylactic acid (acronym "PLA") of a uniform green color.

[0048] The "side wall" of the housing 11 refers to the walls other than the flat surface 14 and the opening to receive the base 12.

[0049] In some embodiments, the housing 11 has side walls with openings that allow limited external light to pass through. These embodiments increase the contrast of the glass edges and barcodes while reducing unwanted reflections and shadows on the glass.

[0050] Compared to solid side panels, 3D printing time is accelerated and the amount of material needed to manufacture the housing 11 is reduced. Furthermore, this produces better contrast in the image captured at markers 17 and 18.

[0051] In some embodiments, the side walls of the housing 11 have openings in front of which are fixed light diffusers of the "tracing paper", frosted transparent plastic, or frosted glass type.

[0052] In other embodiments, the flat surface 14 printed by additive manufacturing has a concave shape representing a predetermined model of a mobile phone or tablet. The optician can then embed the predetermined mobile phone or tablet 30 so that the camera 31 aims at the center of the lens 20.

[0053] In these embodiments, the glass is positioned at the center of the field of view of the lens 31. The shape produced by additive manufacturing is custom-adapted to the mobile phone model. These embodiments also allow for parallelism between the edges of the sensor and those of the flat surface 13, thus eliminating the rotation correction step in the process 50 that is the subject of the present invention.

[0054] In some embodiments, the color of the housing 11 is close to the maximum spectral sensitivity range of the image capture means 30 while also being close to the maximum emission spectrum of the light source(s) located outside the housing 11. For example, a yellow housing 11 could be suitable if the yellow chosen is selected from all possible metameric yellows to be spectrally close to the green corresponding to the maximum sensitivity of the Bayer filters applied to the sensors of most lenses 31, while having a spectrum whose peak is close to the peak emission of the sun.

[0055] In other embodiments, the housing 11 is fixed to the base 12. The housing then includes a removable side door or a side drawer for inserting the lens into the housing. The flat surface 13 can also form the internal part of a drawer that is opened to place the lens inside and closed to take the photograph.

[0056] In other embodiments, the housing 11 is height-adjustable by means of several telescopic elements or sliding strips and retaining pins. This has the advantage of allowing the optimal height to be used for a given lens 31, thus minimizing distortion.

[0057] The device of the present invention also includes the base 12, also called "plate", on which the catadioptric coating 16 is fixed. The catadioptric coating 16 is preferably a rectangle centered on the center of the flat surface 13. Preferably, the rectangle forming the catadioptric coating has two sides of at least 60mm and two sides of at least 70mm.

[0058] In some embodiments, the catadioptric coating has a straight line segment 19 serving as a horizontal reference for the positioning of the lens 20.

[0059] The base 12 has a rectangular parallelepiped shape with a promontory forming the flat surface 13 and a shoulder of dimensions corresponding to the thickness of the housing to receive the openwork face of the housing 11. When the housing 11 and the base 12 are assembled, the device 10 has a rectangular parallelepiped shape, the face with the opening 15 being opposite the face with the base 12.

[0060] The flat surface 13 of the base 12 has at least one two-dimensional barcode, 17 or 18, also called a contrasting geometric pattern or "markers". Preferably, each marker, 17 or 18, is configured to encode a unique identifier representing its position on the flat surface 13. In some embodiments, the unique identifier allows the distance between each barcode and / or the distance from the horizontal reference mark 19 to be determined.

[0061] In some embodiments, the flat surface 13 has at least three two-dimensional barcodes, 17 or 18, representing different codes. Each code represents the unique identifier of the two-dimensional barcode 17 or 18. The presence of three two-dimensional barcodes, 17 or 18, allows, in the same way as the dots of a QR code (registered trademark), the determination of an orientation of the captured image.

[0062] Preferably, the flat surface 13 has five two-dimensional barcodes, 17 and 18, representing different codes, four of which are placed at the corners of a rectangle, the fifth being placed on one of the sides of the rectangle, preferably one of the longer sides. Preferably, the rectangle corresponds to the shape of the retroreflective coating 16. Preferably, the two-dimensional barcode 18 is placed midway between two two-dimensional barcodes 17 placed at the corners of the longer side.

[0063] The two-dimensional barcodes, 17 and 18, are configured to identify shooting parameters dependent on the image capture medium 30. Preferably, the two-dimensional barcodes, 17 and 18, are configured to:

[0064] - calculate the homographic transformation to apply to correct the image when it undergoes distortion due to perspective; the rectangle of the flat surface 13 then appears as a trapezoid,

[0065] - calculate the image scale, that is, the number N of pixels in the image covering a distance of 1 mm of the captured scene,

[0066] - calculate the correction for optical distortion of the image and / or

[0067] - evaluate whether the lighting intensity is sufficient, based on the readability of said markers by the image processing software.

[0068] Preferably, the two-dimensional barcodes, 17 and 18, are configured to determine an angle of rotation of the lens 31 with respect to the flat surface 13, so as to align the sides of this plate with those of the lens 31. To do this, the marker 18, placed between two corners of one of the longer-dimensional sides of the rectangle, indicates the origin of the angles for making angular measurements.

[0069] Preferably, the operator, for example an optician, places the lens with a pre-marked "N" (presumably referring to a specific marking or marking), which is familiar to the professional. A reminder on the reflector sheet informs the optician that once the lens is in place, the horizontal line on the lens must align with the horizontal line on the reflector. A reminder on the reflector itself helps the optician remember that, viewed from above, when the "N" is on the right half of the lens, it is a right-handed lens, and if the "N" is on the left half, it is a left-handed lens. For example, the top right of the reflector might be marked "N->D" and the top left "G<-N".

[0070] Preferably, the two-dimensional barcodes, 17 and 18, are configured to determine the upper part of the ophthalmic lens. The lens is then positioned so that the portion of the lens near the rim of the glasses, configured to be placed near the user's brow bone, is oriented towards the side of the rectangle containing three markers, 17 and 18.

[0071] In some embodiments, the flat surface 13 has four markers, 17 or 18, for determining the homographic transformation. A number greater than four markers, 17 or 18, provides redundancy that enhances the robustness and precision of the method 50 that is the subject of the present invention. Similarly, markers in addition to the centered marker 18 between the two corners of the longer side of the rectangle further increase the robustness and precision of determining the angular correction to be applied.

[0072] In some embodiments, the flat surface 13 has at least one marker, 17 or 18, in the form of a continuous band of contrasting patterns. In some embodiments, the image capture means 30 is configured to provide the image to image processing software which performs the steps of the process 40 described below to detect the outline of the glass, calculate its dimensional measurements and record these and the shape of the glass in a standard file, for example orna, and allowing it to be sent, saved and used locally, or preferably on a remote server.

[0073] The device of the present invention is configured to be compatible with a camera 31 associated with a portable device 30, such as a smartphone or tablet, equipped with lighting, for example a flash. The portable device 30 rests on the upper face 14 of the housing 11, so that the lens 31 and the flash can aim at the flat surface 13 through the opening 15 provided on the upper face 14 by obstructing the opening.

[0074] In some embodiments, the device of the present invention comprises the image capture means 30. The optical parameters related to the lens are then predetermined.

[0075] Preferably, the captured image is then processed by image processing software that detects the outline of the glass, calculates its dimensions, and saves these measurements, along with the shape of the glass, in a standard file (e.g., ORNA) that can be sent to a remote server. This software is hosted and runs on a remote server (a "web app").

[0076] In this preferred embodiment, the measurement of the shape and dimensions of the glass takes place according to the steps described below.

[0077] Figure 4 shows a succession of specific steps in a process 50 for creating a digital file representing the outline of a spectacle lens 20, which includes the following steps:

[0078] -capture 41 of a representative image of a glass 20 positioned in a housing 11 assembled to a base 12 of a device 10, by an image capture means 30 whose lens 31 is placed on the aperture 15 of the housing 11,

[0079] - determination 43 of the shooting parameters of the captured image depending on the image capture method 30,

[0080] - Image correction 45 according to the determined shooting parameters, - Extraction 47 of a curve defining the contour of the glass,

[0081] - Definition 48 of a rectangle circumscribing the extracted curve,

[0082] - Calculation of 49 coordinates of a predetermined number of points on the curve.

[0083] In some embodiments, an application implementing the steps of the process 50 which is the subject of the present invention is hosted and executed locally by means of image capture 30 rather than on a remote server.

[0084] In some embodiments, the capture step 41 is performed by an image capture application previously installed on the image capture means 30, outside of said application. In these embodiments, the image is first captured and then loaded into the application for processing. The method 50 of the present invention may include a manipulation phase prior to the capture step 41. Such a phase includes:

[0085] - a step involving opening the case 11,

[0086] - a step of tracing a horizontal line on the glass 20,

[0087] - a step of placing the glass approximately in the center of the catadioptric coating 16 surrounded by the markers, 17 and 18, so that the horizontal line of the glass is superimposed on the horizontal line 19 marked on catadioptric coating 16, and - a step of closing the housing 11.

[0088] During this handling phase, the opening and tracing steps can be reversed.

[0089] Capture step 41 may include at least one of the following steps:

[0090] - launching an image capture application on the image capture means 30, - positioning the image capture means 30 on the flat surface 14 of the housing 11 so that the lens 31 and the flash can aim at the flat surface 13 through the opening 15 provided on the upper face 14 by obstructing the opening,

[0091] - Activating the flash of the image capture device 30 manually or automatically within the application,

[0092] - Image capture from the application, in a manner known to those skilled in the art. In process 40, steps 42 to 50 represent image processing steps. These image processing steps are carried out locally by computer means of the image capture device 30 or on a remote server.

[0093] Preferably, the process 40 includes, prior to the step of determining the shooting parameters of the captured image 43, a step of adapting the contrast of the captured image 42.

[0094] During adaptation step 42, several contrast levels are applied to the captured image using image processing, and one contrast level is selected. The selected contrast level is the first level at which each two-dimensional barcode 17 and 18 can be read and decoded. Preferably, the contrast level is adapted in steps.

[0095] In some embodiments, if no contrast level can be selected, the process notifies the user that a new image capture must be performed. Such notification may take the form of displaying an error message, for example. In particular, such a situation may occur if the flash has not functioned, resulting in an image that is too dark to be processed correctly later.

[0096] The step 43 for determining shooting parameters preferably includes at least one step 44 for comparing the image of each captured two-dimensional barcode with a graphical representation of each two-dimensional barcode and a step 44 for calculating at least one representative value of at least: - a homography,

[0097] - a distortion and

[0098] - a rotation.

[0099] For example, a two-dimensional barcode is generally composed of black and white square cells. In case of distortion, the cells will have a different shape; for example, the cell will no longer be a square, but a rounded square. By comparing the captured image to the original image of the two-dimensional barcode, it is possible to quantify each distortion and apply an opposing distortion through image processing to correct these defects due to image capture.

[0100] For example, determination step 43 includes at least one of the following steps: - calculation of the homographic transformation of the captured image due to perspective, - calculation of the image scale,

[0101] - calculation of the optical distortion of the image and / or

[0102] - calculation of a rotation angle of the objective 31 with respect to the flat surface 13.

[0103] In some embodiments, the method of the present invention implements an algorithm for calculating the uniformity of lighting based on the clear bands left free of any pattern on the lower plate. Evaluating the uniformity of lighting ensures that there is no risk of reflection that could obscure the outline of the glass and prevent its detection. If a risk of reflection obscuring the outline of the glass is detected, the method notifies the user that a new image capture must be performed with a different positioning of the image capture means.

[0104] Preferably, the captured image correction step 45 includes at least one rotational straightening step 46, one homographic straightening step 46, and / or one distortion correction step 46 for the captured image based on the calculated representative value. Preferably, when the process 40 includes a distortion correction step 46 and a homographic straightening step 46, the distortion correction step precedes the homographic straightening step.

[0105] For example, the 46th step of the rotating image rectification is based on the five markers to determine the angular orientation of the camera sensor relative to the edges of the lower face supporting the glass /

[0106] For example, the distortion correction step is based on the five markers and the edges of the bottom face.

[0107] In some embodiments, the distortion correction 45 can be achieved by calculating the difference between an expected reference image and a real image, extracting the offset vectors between paired points on these two images (optical flow) and calculating, from these vectors, a distortion correction matrix over the whole image.

[0108] In some embodiments, distortion correction 45 can be achieved by pre-calibrating camera models on the market, recording these pre-calibrations in a database, asking the optician user to enter the model of phone or tablet used, and then applying the correction parameters thus pre-established for that specific device model.

[0109] In some embodiments, distortion correction can be achieved by associating one or more distortion measurements with an optimal shooting height, thus determining the 3D printing height of the casing. Alternatively, this optimal casing height, which limits distortion, can be determined using a database that associates optimal heights with commercially available smartphone and tablet models. In some embodiments, image dynamic range can be increased and noise reduced by multiplexing several shots, a technique known to those skilled in the art as High Dynamic Range (HDR).

[0110] Extraction step 47 is performed on the corrected image. Extraction 47 of the glass contour provides a table of values ​​containing the absolute Cartesian coordinates, relative to the origin of the image coordinates, of each point of this contour.

[0111] During definition step 48, a rectangle is calculated. The rectangle is defined to be tangent to the contour on each side, without intersecting the extracted contour. In other words, the rectangle encompasses the lens and its center, that is, the origin point of the lens. Definition step 48 includes an application step of a process known as "boxing," commonly referred to as "squaring" or "boxing," and familiar to those skilled in the art of optics and eyewear.

[0112] The definition step 48 provides horizontal dimensions called "hbox" and vertical dimensions called "vbox" of said rectangle.

[0113] During calculation step 49, the absolute Cartesian coordinates of each point of the contour are converted into coordinates relative to the origin point of the glass.

[0114] Preferably, the Cartesian coordinates are converted into polar coordinates of each point on the contour relative to the origin of the lens. During this conversion step, distances are measured between the point on the contour and the origin of the lens, and the angle between a point on the contour and the horizontal is measured for all points on the contour.

[0115] Preferably, the process 40 of the present invention further comprises a generation step 50 of a standardized digital file representing the contour of the glass from the coordinates of the calculated points.

[0116] During generation step 50, the polar coordinates are recorded in at least one table of values. For each angle increment of 0.9 degrees, corresponding to 400 points distributed over 360 degrees, the index corresponding to that angle is found in the table of angles, and the distance for the desired angle is interpolated. An ORNA standard file is generated by concatenating all the interpolated distances thus found, the angle values ​​being implicit in this file. In optional embodiments, the method of the present invention includes an optional step of processing such a file. The ORNA file can then be saved locally on the portable device, or sent and saved to a server, or sent to another application that automatically performs 3D modeling of the frame adapted to the measured lens for manufacturing said frame by a 3D printer.

[0117] In some embodiments, the area inside the glass can be used to determine other geometric parameters of the glass such as: thickness, relief of the glass and / or three-dimensional shape of the glass.

[0118] In preferred embodiments, the process 40 of the present invention comprises a manufacturing phase 90 of a lens frame from the standardized digital file, by additive printing. This manufacturing phase 90 is described below with reference to Figure 9.

[0119] Figure 5 shows a device 60 for manufacturing a frame for a pair of glasses from at least one lens to be inserted into it, which includes:

[0120] - a computer system 61 configured to represent, in at least two dimensions, the outline of at least one lens and to provide a file containing information representative of this outline,

[0121] - a calculation method 62 for the eyeglass frame adapted to receive and retain each lens, based on the representation of each lens contour,

[0122] - a control means 64 of a manufacturing machine 63 of the calculated mount and - possibly, a slicing means 65 (“slicer” in English).

[0123] In the preferred case where the manufacturing machine 63 is a 3D printer, the device 60 ensures the printing of a frame for a pair of eyeglasses tailored to the shape of the lenses.

[0124] The computer means 61 determines the shape of the outline of the glass 70 shown in figure 7 and saves it in a file of standardized format as described opposite figure 4.

[0125] The optician also determines the 73 distance between the lenses, either by taking a measurement on the old frame, or by reading this distance on a branch of the old frame.

[0126] The manufacturing machine 63 can use different materials, either subtractively, for example by grinding wood or a plastic material, or additively, for example with a 3D printer using a material-curing laser or a nozzle-type printing system with a plastic material. In an embodiment where the manufacturing machine is a 3D printer, the material is preferably PLA (polylactic acid, a plant-based plastic) or ABS (acronym for acrylonitrile butadiene styrene, a thermoplastic polymer) for reasons of flexibility. Preferably, the 3D printer prints with a bio-based, biodegradable, and / or recyclable material. The computing means 62 is preferably the programmable logic controller integrated into the computer system.The control means 64 is a programmable computer system, for example a calculator, a computer, or an online server. In variants, the computing means 62 and the control means 64 are combined into a single computer system, possibly integrated into the computer system 61.

[0127] The slicing means 65 is suitable for the case where the control means 64 generates an "stl" file representing the 3D mount. The slicing means 65 retrieves this stl file to perform the slicing and generates a "gcode" file which it sends to the manufacturing machine 63.

[0128] The calculation means 62 and the control means 64 jointly perform steps 91 to 97 illustrated in figure 9. The slicing means 65 performs step 100 illustrated in figure 9.

[0129] The steps described below are described after step 50 in which a standardized digital file is generated representing, in at least two dimensions, the outline of a first glass and, possibly, of the second glass, if it has a different shape from the first glass.

[0130] In step 91, the computing means 62 determines and stores the representation of the second glass if only one glass has been represented. This representation of the second glass is the reflection of the representation of the single glass shown with respect to an axis perpendicular to the horizontal axis of the glass.

[0131] In step 92, the computing means 62 positions the contour representations of the two lenses in the memory of computer 64 so that their distance corresponds to the distance of the lenses on the old frame and their horizontal axes are common. For example, it saves this scan in "Orna" or "xml" format on the hard drive of computer 64.

[0132] In step 93, the computer 64 determines the circles 76 surrounding the lenses by incorporating the grooves corresponding to the counter-bevels of the lenses. These circles can have a variable thickness around the edge of the lens, depending on aesthetic choices made by the user or the optician, particularly if it is desired that the new frame resemble the original damaged frame as closely as possible.

[0133] During step 94, the computer 64 determines a bridge shape 77 between the rims. This bridge shape can be constant for all frames to be manufactured or can depend on the type of the old frame and / or the age of the glasses wearer. For example, the optician enters an indication of whether the old frame was metal or plastic, and whether the frame was semi-rimless. Thus, the bridge of the new frame can vary depending on the type of the original frame. For example, a "key-nose" bridge is preferentially used for a lens spacing of at least 21 mm. Similarly, for children, whose noses do not have the same curvature as an adult's, the bridge, positioned more in the middle of the lens height 20 than for an adult, compensates for the difference in morphology. Of course, the wearer's aesthetic preference can optionally be taken into account.

[0134] In step 95, the computer 64 determines a tenon shape 78 to support each hinge. The shape of this tenon is aesthetically consistent with the shape of the bridge. This shape preferably includes a recess to house a fixed part of the hinge, for example, a standardized metal hinge. Alternatively, this fixed part of the hinge is integrated into the tenon and includes at least one vertical through-hole to accommodate a pivot shaft for the part of the hinge integrated into or supported by a branch. Note that the width of the tenon (width measured in the horizontal direction in Figure 8) corresponds to the distance between the circle and the hinge. This distance is standardized in a preferred mode. However, it can be slightly modified to accommodate aesthetic adjustments.It is noted that the positions of the hinges preferentially correspond to an angle between the deployed arms and the plane of inclination of the lenses of approximately 8 degrees.

[0135] In step 96, computer 64 determines the shapes of the temples to ensure aesthetic consistency with the bridge, tenons, and rims, and optionally with a specific aesthetic choice. Alternatively, the temples are standardized or not manufactured by the production machine. In this case, step 96 is not performed.

[0136] Optionally, during a step 97, the computer 64 determines the color or color distribution of the frame, for example based on a color indication of the old frame or aesthetic choices made by the wearer.

[0137] The mount to be manufactured 75 is thus completely designed in the memory of the computer 14, in three dimensions, at the end of step 97.

[0138] Of course, depending on the embodiment, the order of steps 98 to 104 may vary. Similarly, in the case of a clip-on sunglass lens, the determinations of the tenons, hinges, and temples will be replaced by a determination of the part of the frame intended to receive the clip positioning mechanism.

[0139] It should be noted that, for frames made from a flexible material, the curvature of the frame is determined by the lenses. The optician gently heats the frame to allow the lenses to be clipped in. It is at this stage that the frame acquires its curvature, because the heat makes it more flexible and allows it to conform to the curvature of the lens. In some variations, the bridge and / or rims are designed to promote a curvature of approximately 4° between the mean planes of the lenses.

[0140] In the case where the manufacturing machine 63 uses a rigid material, for example wood, metal or a rigid plastic material, the computer means performs a three-dimensional representation of the end of the counter-bevel of at least one glass 70. The shape of the glass 70 is then provided in the form of a three-dimensional representation.

[0141] Further details of embodiments of the device that is the subject of the invention are given below.

[0142] A particular embodiment of the manufacturing phase of the process that is the subject of the invention is broken down into several steps occurring in the following chronological order:

[0143] - step 98: software builds a mesh to be used by the manufacturing machine; - step 99: this same software generates a 3D model description file usable by manufacturing machines (a non-limiting example of which is a file in ".stl" format);

[0144] - step 100: depending on the manufacturing process used, an intermediate software called a "slicer" (also called slicing software or slicing software) between the previous software and the manufacturing machine can retrieve the file generated in step 99 to convert it into manufacturing instructions specific to the machine used;

[0145] - step 101: the manufacturing file, generated as appropriate in step 99 or 100, is sent by the control means, by any means of communication (radio or wired, recording on a memory medium or removable electronic device connected directly to the computer) to the manufacturing machine;

[0146] - Step 102: The manufacturing machine reads the received file and uses the description of the 3D model it contains to physically manufacture the frame generated in steps 91 to 97. This manufacturing machine can use any material transformation process at its disposal. This material transformation process may include, but is not limited to, 3D printing, plastic injection molding, CNC machining (Computer Numerical Control), laser engraving, etc. This machine can use any material, such as plastic, metal, or wood; optionally, the optician performs a surface finishing step on the frame, such as deburring, or a heat or chemical treatment to improve the polished appearance of the frame.

[0147] - step 103: The optician attaches the temples. These temples have already been manufactured in advance by any process whatsoever or are manufactured by the manufacturing machine used in step 40 or a similar machine;

[0148] - step 104: the optician positions the lenses in the frame and hands the pair of glasses to the wearer.

[0149] The frame generated by this process is thus adapted to the wearer's lenses, to the wearer's own characteristics and to those of the frame to be repaired or replaced, since it corresponds to the dimensions of his lenses and to the data provided by the optician.

[0150] In some embodiments, the calculation means estimates or measures a difference between the actual perimeter of the glass contour at the end or at the foot of its counter-bevel, in three dimensions due to its curvature, and the perimeter in two dimensions represented by the data provided by the computer means 61. Indeed, when the computer means 61 provides data representing the contour of a glass only in one plane, this induces a first difference between these perimeters.

[0151] Alternatively or complementarily, in embodiments, the calculation means estimates or measures a difference between the actual perimeter of the glass contour at the end or at the foot of its counter-bevel, in three dimensions due to its curvature, and the perimeter of a two-dimensional print, that is to say a print in which the front face of the future frame being printed is tangent to the plane on which the additive printing is carried out, the first printing planes including all of this front face.

[0152] Indeed, when printing is done in two dimensions, this introduces a second difference. Each of these first and second differences can cause the frame to break when it is mounted on the lens.

[0153] In these embodiments, the calculation method estimates or measures the actual perimeter based on:

[0154] - the curvature of the contour of the counter-bevel of the lens, measured in a plane tangent to this contour and including the optical axis of the lens, this curvature being able to be estimated from the average curvature of the lenses, between four degrees and six degrees or from the curvature measured by an operator,

[0155] - the form factor of the glass, the ratio between the largest and smallest dimensions of the glass outline.

[0156] This difference is then used by the calculation method to increase the perimeter of the circle of the frame to be printed. This increase can be an addition of the difference or a multiplication by the ratio of the perimeters; both correction methods ensure a correspondence between the perimeter of the printed circle and the actual perimeter of the lens.

[0157] In some embodiments, the device further includes a layer-by-layer additive manufacturing machine. The printing material is a flexible material, and the computing means is configured so that the entire surface of the frame surrounding the lenses is printed from the first layer. Thus, manufacturing can be less expensive, and no rework is necessary for the rims surrounding the lenses. The flexibility of the material constituting these rims ensures the frame's ability to deform and adapt to the lenses of the glasses. In other words, although the lens is three-dimensional and not plane-like, which implies that the frame, once mounted on the lens, will take on a non-planar shape, in these embodiments, the frame rims are printed in two dimensions from the first layer by adding material.The successive planes create a flat mount tangent to the plane on which the printing is carried out by depositing material.

[0158] This avoids having to deal with the imperfections of a three-dimensional print on a flat support, which requires printing temporary supports under the useful printed part that corresponds to the final mount.

[0159] Preferably, the calculation method is configured to enforce a predetermined criterion between:

[0160] - the curvature of each circle surrounding a lens intended to fit within that circle and into a plane tangent to the lens and comprising an axis parallel to the optical axis of that lens,

[0161] - the radial cross-section of each circle, that is, in a plane perpendicular to the plane tangent to the lens and having an axis parallel to the optical axis of the lens, and - the yield strength before breakage of the printing material. This predetermined criterion defines impossible combinations between this curvature, this radial cross-section, and the yield strength before breakage. Thus, although the frame must be deformed to adapt to the lenses, the calculation method anticipates the geometric characteristics of the printed frame and reduces the risk of breakage, while allowing for choices, for example, aesthetic ones, in the definition of this frame. Thus, the radial cross-section of each circle of the frame is, in these embodiments, adapted to the lens, whose contour dictates the bending of the circles according to the curvature indicated above and to the yield strength without breakage of the material used.

[0162] Preferably, the calculation method is configured to define each circle based on the curvature of each lens intended to fit within that circle and within a plane tangent to the lens and having an axis parallel to the optical axis of that lens. Thus, the perimeter of the circle, once deformed to surround the lens, corresponds to the non-planar perimeter of the lens, plus a tolerance, for example, fixed or proportional to that perimeter.

[0163] In some embodiments, the calculation method is configured to estimate the curvature of the lens based on a lens shape factor and a lens curvature. Thus, although the lens outline is represented in two dimensions, the difference between the perimeter of this represented outline and the perimeter of the actual outline can be estimated and taken into account in defining each circle of the frame. The shape factor is minimal when the lens has a perfectly round outline and maximal when the ratio of the larger dimension of the lens outline to its smaller dimension is maximized, for example, in the case of a rectangular lens with a maximum ratio of the longer side to the shorter side. The higher the shape factor and the lens curvature, expressed in degrees, the higher the ratio between the actual perimeter of the lens and the perimeter of the two-dimensionally represented outline.These methods of implementation anticipate this difference and this ratio and thus reduce the risks of breakage of the frame when mounting the frame onto the lens.

[0164] Preferably, the computer means 61 is configured to represent the contour of a counter-bevel formed on the contour of the glass, and the calculation means is configured to:

[0165] -deduct a portion of an estimate of the difference between the contour of the counter-bevel and the contour of the glass outside this counter-bevel,

[0166] - define circles with a drageoir corresponding to this counter-bevel.

[0167] Thus, the counter-bevels can fit into grooves in the frame's circles. Preferably, the device includes the additive manufacturing machine, which produces the lens in successive planes. The computing means is configured so that the groove is uniformly formed in the same successive planes for the entire circle of the frame surrounding the lens. Therefore, the counter-bevel of the lens is located at the same distance from the front surface of the frame once the frame is mounted on the lens. Preferably, the computing means is configured to form a counter-bevel facing the lens in at least one circle of the frame. In this way, the frame simulates the presence of a thread, for example, nylon (registered trademark), for a lens designed to be held by such a thread.

[0168] Preferably, the calculation method is configured to produce two different circles for lenses with different contours. Thus, recycled lenses can be used to create new frames, for example, for the provision of eyeglasses by non-governmental organizations to the poor population of developing countries.

[0169] Preferably, the calculation method is configured to form a circle around each lens, with a portion 79 (see Figure 8, for the right-hand circle) positioned away from the lens contour at the bridge 77 between the lenses 71. This bridge 77 thus presents two arms on each lens (in Figure 3, on a single lens, for illustrative purposes). This allows for additional flexibility to facilitate the insertion of the lenses 71 into the frame 75.

[0170] All subsequent variations follow the process described above.

[0171] In a second variant, process 40 is carried out using both lenses of the frame.

[0172] Preferably, manufacturing phase 90 includes a step during which the optician enters data concerning the glasses into a user interface of a calculation software; this data includes, in particular, the distance between the lenses and, possibly, other data indicated opposite Figure 8.

[0173] In some variations, process 40 results in a topographic data file that can be used by software to convert this data into the format required by a cutting machine, for example, but not limited to, a laser cutter or a CNC machine. This cutting machine can then use this file to custom-cut one or more occlusion filters to dimensions adapted to the wearer's eyeglass lenses. These occlusion filters can be, but are not limited to, Ryser, "Press-On," or self-adhesive solar films.

[0174] In some variations, process 40 is carried out at the bearer's home.

[0175] In one variant, process 40 is carried out in any location other than at the optician's or the wearer's home, provided that said location has the appropriate equipment and software.

[0176] In one of the variants, step 102 is carried out automatically by a machine adapted to this specific task of attaching the branches to the hinges.

[0177] In one variation, steps 101 and 102 are carried out at a shared manufacturing center where the wearer can pick up their finished frames. Alternatively, this center can ship the finished frames to any location approved by the wearer. In other variations, steps 101 and 102 are carried out at the wearer's home or any other location available to them where they have access to a manufacturing machine compatible with this process for having their frames made. If the frames are manufactured outside their home, the wearer can pick them up there after they have been made or have them delivered to any location of their choosing.

[0178] As can be understood from the preceding description, the present invention allows for the rapid and lasting provision of replacement eyeglasses, compared to a makeshift repair. In cases where the old frame has been damaged, this rapid provision reduces the risks associated with potentially hazardous professional or personal activities, such as handling toxic products or operating machinery.

[0179] Figure 6 shows a radial section 67 of a rim of a frame made by implementing the present invention and a portion of a lens 66. In particular, the counter-bevel 68 and the drageor 69 are visible. The offset is the displacement between the outer end (bottom in Figure 6) of the counter-bevel 67 and the inner face (top in Figure 6) of the radial section 66. The radial section 66 of each rim lies in a plane having an axis parallel to the optical axis of the lens and perpendicular to the plane tangent to the lens having an axis parallel to the optical axis of this lens.

[0180] Two variants of the software used to implement manufacturing phase 90 of the process that is the subject of the invention are described below. An import is performed of the file whose extension is "orna" or another format generated by the computer equipment 61 usually used and available to a person skilled in the art.

[0181] We analyze this file and extract two data lists into computer memory: List_OD for the right eye and List_OG for the left eye. Each list contains a sequence of points, and each point consists of the recorded coordinates (in two or three dimensions).

[0182] A list of additional points, `Liste_Section`, stores a predefined shape for the frame section. This `Liste_Section` can originate from a storage medium on the computer running the software. The advantage of defining it on an internal or external storage medium is that it allows a person skilled in the art to redefine these parameters themselves according to evolving professional practices. Similarly, it allows for adapting tolerances to the specific constraints of the material used for 3D printing. These parameters can be modified either directly in the file or through a user interface integrated into the main algorithm. The predefined shape is chosen according to the dimensions known to a person skilled in the art for a correct fit of the lenses in the frame's groove or channel, as shown in the figure below:

[0183] This section is then extruded, that is to say applied, along the contour of the mount by duplication of this section and successive stacking of such sections to constitute each successive layer giving rise to the 3D mesh of the mount, recorded in the computer's memory: Mesh_Mount.

[0184] In the lists Liste_OD and Liste_OG, we select the points located in a predefined area to the left of the right lens and to the right of the left lens, said areas being located in the upper part of the frame.

[0185] The selected points are moved along the normal to the curve at each point. The two curve arcs thus formed are stored in memory in two lists: List_AD and List_AG.

[0186] We use a parametric extrapolation or interpolation method such as the Bézier method, or a spline method such as the Catmull-Rom method or the Hermite polynomial method. This method allows us to close the curve sketched in the previous step to form the bridge between the two glasses.

[0187] The list of points forming the bridge curve, List_Bridge, integrates List_AD and List_AG and adds the points calculated by interpolation or parametric extrapolation; it is stored in the computer's memory.

[0188] An extrusion along the Oz axis, performed from the bridge plane by successive stackings, defines a 3D mesh of the bridge stored in memory: Bridge_Mesh.

[0189] To create the frame's tenons, the same principle is used as for creating the bridge: in a predefined area on the upper right edge of the right lens and the upper left edge of the left lens, points from the curve are extracted from the List_OG and List_OD. These points are saved in two new lists: Tenon_OD and Tenon_OG.

[0190] By extrusion along the Oz axis, the different stacked planes for each tenon are recorded in two memory areas: Mesh_Tenon_OD and Mesh_Tenon_OG.

[0191] Predefined hinge meshes, Hinge_Mesh_OD and Hinge_Mesh_OG, are imported from a storage medium (ROM) of the computer or already defined in the body of the program and are combined in RAM with the mesh of each of the tenons.

[0192] All the meshes thus created: Mesh_Mount, Mesh_Bridge, Mesh_Tenon_OD, Mesh_Tenon_OG, Mesh_Hinge_OD and Mesh_Hinge_OG, are then grouped within the same memory area: Mesh_Mount_Complet.

[0193] This record, Maillage_Monture_Complet, is then:

[0194] - either converted into a file whose format (STL type or other) is compatible with the input formats accepted by commercial slicing software, which slicer aims to transform the STL format file into a file made up of codes interpretable by the electronics of a 3D printer (typically, but not exclusively, a gcode format);

[0195] - either directly converted, within a final step of the algorithm described above, into a file consisting of codes interpretable by the electronics of a 3D printer (typically, but not exclusively, a gcode format); The software described above can be hosted by a computer within an optician's shop, by a remote server or directly in an electronic control board of a 3D printer.

[0196] A second variant of the software is described below.

[0197] We import the outlines from the orna file, or equivalent, (fields taken into account: -FILENAME, OMAV, DBM, HBOX, VBOX, TRCFMT, R, A):

[0198] - variant with only one or two contours (completed by symmetry if necessary) - reading the list of radii

[0199] - reading the optional list of ray angles (otherwise they are calculated regularly from 0 to 360°)

[0200] - reading the distance from the center of the left eye to the center of the right eye

[0201] - reading the distance between the lenses

[0202] - lens size (hbox + vbox).

[0203] We calculate 2D positions of the mount elements, which can be modified using the algorithm's parameters:

[0204] - width and support points of the nose (top starting point, top midpoint, bottom starting point, bottom midpoint)

[0205] - thicknesses and extension of the tenons

[0206] - total width of the frame.

[0207] We detect impossible geometric constraints.

[0208] We model in two dimensions using closed splines:

[0209] - Calculation of a closed spline curve based on radial sampling of glasses (simplification and acceleration, the error between the spline and the sampling is adjustable)

[0210] - calculation of the bridge based on a closed spline and anchor points on the left and right circles (see diagram).

[0211] We perform an extrusion of a profile along the 3D spline (a "sweep" operation of a 2D shape perpendicular to a path in space, here the support splines):

[0212] - partial semi-circular profile for the nose

[0213] - partial semi-circular profile (external) for the circle and straight with a groove for the drageoir (adjustable).

[0214] Plates are added along the circles (position, length, height, adjustable offset).

[0215] Hinges are defined with an external chamfered (rounded) profile and internal turns with adjustment angles.

[0216] We create a virtual assembly of:

[0217] - left eye, right eye, defacement

[0218] - nose (bridge)

[0219] - plates - tenons and hinges.

[0220] We perform an export, according to one of the following formats:

[0221] - STL (faceted approximation)

[0222] - STEP (a mathematically pure shape CAD file)

[0223] - SVG 2D (without facets).

[0224] The advantages of this second variant compared to the first are:

[0225] - the absence of facets in the generated shape may lead to an adjustment of the printing precision during the last step, that of the generation of the file for 3D printing (STL file);

[0226] - the generation of a pure mathematical form is compatible with industrial CAD software (STEP format) and therefore allows machining by processes other than 3D printing;

[0227] - Similarly, this pure mathematical form allows a 3D vector view (therefore able to be enlarged infinitely; SVG file) of the generated mount to be presented for validation by a person skilled in the art before 3D printing.

[0228] To highlight these advantages, as well as the dimensions chosen in practice, here is a list of parameters that can be modified and their default values:

[0229] -stl file (optional): path of the STL file to generate - step file (optional): path of a STEP file to export -svg file (optional): alternate SVG file to export to - log file (optional): log file to output to (instead of stdout)

[0230] - Frame thickness (mm) - Optional thickness seen from side (Default: 3.2)

[0231] - rim-offset mm offset applied to OMA radii (Default: -0.1), offset applied to the OMA radii (default: -0.1)

[0232] - Rim precision (mm) of OMA curve (1mm is good) (Default: 1.0)

[0233] - rim-width-mid mm thickness of the circles seen from face (Default: 2.4), thickness of the circles seen from front (Default: 2.4)

[0234] - rim-width-outer mm optional thickness of the top & bottom circles seen from side (Default: 1.6), optional thickness of the top and bottom circles seen from the side (Default: 1.6) - hinge-hole-size mm hinge hole size (consider a +0.2mm margin) (Default: 2.65) hinge hole size (consider a +0.2mm margin) (Default: 2.65)

[0235] - Hinge-hole-rot degree: rotation of hinge holes on their axis (Default: 5)

[0236] - hinge-pos mm y-coordinate of hinges (Default: 8), y-coordinate of hinges (Default: 8) - hinge-outwards mm outwards displacement of the hinge (origin is the outer circle edge) (Default: 4), outwards displacement of the hinge (origin is the outer circle edge) (Default: 4)

[0237] - Hinge thickness (mm margin around the hinge holes) (Default: 2.4)

[0238] - temple-height mm temple height (sets hinge height) (Default: 6.5), temple height (sets the hinge height) (Default: 6.5)

[0239] - hinge-flare mm, hinge thinning (Default: 1) - hinge-edge-rounding mm, hinge edge rounding (Default: 2)

[0240] - bridge-top-start mm, y-coordinate of bridge top sides (Default: 21), y-coordinate of the upper sides of the bridge (Default: 21)

[0241] - bridge-top-center mm, y-coordinate of bridge top center (Default: 11), Y-coordinate of the bridge top center (Default: 11)

[0242] - bridge-top-flat mm bridge top flat width (Default: 4), width of the bridge top flat (Default: 4)

[0243] - bridge-bot-start mm, y-coordinate of bridge bottom sides (Default: -9), Y-coordinate of the bottom sides of the bridge (Default: -9)

[0244] - bridge-bot-center mm, y-coordinate of bridge bottom center (Default: 10), Y-coordinate of the center of the bottom of the bridge (Default: 10)

[0245] - bridge-bot-flat mm bridge bottom flat width (Default: 3), width of the flat bottom of the bridge (Default: 3)

[0246] - bridge-inset mm inset of bridge sides (0 to be tangent to the circles) (Default: 2), Inset of the bridge sides (0 to be tangent to the circles) (Default: 2)

[0247] - rim-bezel-height mm, height of the bezel (Default: 1.8),

[0248] - rim-bezel-depth mm depth of the candy dish (Default: 0.8),

[0249] - pad-position mm vertical offset of the pads on the iso line (Default: -2)

[0250] - Pad length (mm) (Default: 15)

[0251] - pad-depth mm pad depth (Default: 4.5)

[0252] - pad thickness mm (Default: 1.8)

[0253] - pad-flare-angle deg, pad flare angle (Default: 20)

[0254] - Total width mm optional, overrides hinge 'outwards' width (custom), replaces the "outwards" hinge width (custom),

[0255] - bridge-width mm optional, overrides OMAdbl definition (custom), replaces the OMAdbl definition (custom),

[0256] - bridge-pos mm optional, overrides bridge vertical position (0 is centered), replaces the vertical position of the bridge (0 is centered)

[0257] - box-height mm optional, overrides OMA box height, replaces the OMA box height - box-width mm optional, overrides OMA box width, replaces the OMA box width.

[0258] The "frame thickness" is the thickness in millimeters of the frame when viewed from the side. The default value is chosen to account for the material's rigidity and elasticity. The frame is thin enough for fast printing, yet rigid enough to securely hold the lenses.

[0259] Regarding the following variables:

[0260] - rim-offset mm offset applied to OMA radii (Default: -0.1)

[0261] - rim-precision mm precision of OMA curve (1mm is good) (Default: 1.0)

[0262] - rim-width-mid mm thickness of the circles seen from face (Default: 2.4)

[0263] - rim-width-outer mm optional thickness of the top & bottom circles seen from side (Default: 1.6)

[0264] The circle settings shown here correspond to the front view of the frame. The rim-width-mid thickness, here 2.4 mm, is chosen to allow for cold-clipping of the lenses. A frame that is too thick is unsightly and makes lens insertion too difficult. Conversely, a frame that is too thin tends to break when the lenses are being fitted.

[0265] Regarding the variables:

[0266] - hinge-hole-size mm hinge hole size (consider a +0.2mm margin) (Default: 2.65) - hinge-hole-rot deg rotation of hinge holes on their axis (Default: 5)

[0267] - hinge-pos mm y-coordinate of hinges (Default: 8)

[0268] - hinge-outwards mm outwards displacement of the hinge (origin is the outer circle edge) (Default: 4)

[0269] - hinge-thickness mm margin around the hinge holes (Default: 2.4)

[0270] They are related to the configuration of the hole that must receive the metal hinge, itself selected for reasons of strength and commercial availability.

[0271] The hole size allows the hinge to be pressed securely into place. This is achieved without heating the material. With these parameter values, the hinges remain "sealed" once installed without the need for screws or glue to secure them in the frame. This creates a "cold clip" effect within the frame.

[0272] A five-degree rotation is chosen here to allow the arms to overlap when bent. This is a parameter that depends on the hinge model used. This default value was selected after several test prints.

[0273] The height of the tenon, as seen from the front view where the hinge hole is located, is chosen primarily for aesthetic reasons. Eight mm corresponds to the height from the ISO boxing reference.

[0274] The distance between the rim and the hole (4mm) is a default setting selected to ensure sufficient resistance when the frame is under tension as the temples are pushed against their end during opening and placement on the wearer's face. A larger value increases leverage, excessively deforming the frame (due to the flexibility of the material used). A smaller value results in an overall narrower frame, preventing a proper fit of the frame to the customer's face (deviating from the original frame width measured by feel, which has temples closer to 6-7mm on average).

[0275] The material margin surrounding the hole is set here by default to 2.4 mm to allow proper support for the hinge in order to promote cold sealing to ensure good support of the hinge in the face.

[0276] Regarding the variables:

[0277] - temple-height mm temple height (sets hinge height) (Default: 6.5)

[0278] - Position of the lower part of the tenon resulting from the other adjustments

[0279] - hinge-flare mm hinge thinning (Default: 1)

[0280] - hinge-edge-rounding mm

[0281] - hinge edge rounding (Default: 2)

[0282] These values ​​correspond to the rounding of the tenon in front view, and result from an aesthetic choice.

[0283] Regarding the variables:

[0284] - bridge-top-start mm

[0285] - y-coordinate of bridge top sides (Default: 21)

[0286] - bridge-top-center mm

[0287] - y-coordinate of bridge top center (Default: 11)

[0288] - bridge-top-flat mm bridge top flat width (Default: 4)

[0289] - bridge-bot-start mm

[0290] - y-coordinate of bridge bottom sides (Default: -9)

[0291] - bridge-bot-center mm

[0292] - y-coordinate of bridge bottom center (Default: 10)

[0293] - bridge-bot-flat mm bridge bottom flat width (Default: 3)

[0294] - bridge-inset mm inset of bridge sides (0 to be tangent to the circles) (Default: 2). All values ​​are chosen so that the bridge always has a sufficiently strong structure to contain the deformation induced by the opening of the temples and by the placement of the frame on the face.

[0295] The settings allow us to take into account the multiple scenarios related to the two variables which induce constraints on the generation of the 3D model, namely the distance between the two lenses and the shape of the lenses.

[0296] Regarding the variables:

[0297] - rim-bezel-height mm

[0298] - height of the candy dish (1.8)

[0299] - rim-bezel-depth mm depth of the candy dish (Default: 0.8)

[0300] - pad-position mm vertical offset of the pads on the iso line (Default: -2) - pad-length mm length of the pads (Default: 15)

[0301] - pad-depth mm pad depth (Default: 4.5)

[0302] - pad thickness mm (Default: 1.8)

[0303] - pad-flare-angle deg

[0304] - brake pad caster angle (Default: 20)

[0305] The position of the nose pads is adjusted here to avoid interfering with the bridge position. The thickness of the pads is set to 1.8 mm to ensure they do not exceed the frame thickness (2.4 mm) in the front view profile. The other parameter values ​​were chosen after several impressions to achieve a comfortable fit. The relationships between these parameter values ​​are detailed in a nose pad conversion table based on the type of nose bridge or frame, as described in the previous document.

[0306] Examples of the criteria governing the completion of this lookup table include:

[0307] - A smaller lens corresponds to a larger offset, to compensate for the reduced flexibility of the frame, with the same radial section.

[0308] - A lens with a more rectangular shape factor corresponds to a larger offset to compensate for the curvature of the contour, with the same radial section.

[0309] - A lens with a more rectangular shape factor corresponds to a smaller radial cross-section, to increase the flexibility of the lens contour in bending.

[0310] An example of a lookup table showing offset relative to the probed shape is given below:

[0311] [Table 1]

[0312]

[0313] An example of a table showing the offset correspondence with respect to lens power is given below:

[0314] [Table 2]

[0315]

[0316]

[0317] Note that these correspondence tables may prohibit certain colors (which correspond to more limited elasticities before breakage) for certain combinations of radial section, glass shape, glass curvature, ...

[0318] Below is an example of a correspondence table for the geometry of the plates in relation to the shape factor of the lens and therefore of the frame.

[0319] [Table 3]

[0320] An example of the relationship between the curvature of the lens, which can be high in the case of sunglasses and can influence the tolerance to be added to the lens contour to define the frame's internal contour and compensate for the curvature, is given below: [Table 4]

[0321]

[0322] DESCRIPTION OF THE INVENTION

[0323] According to a first aspect, the present invention relates to a standardized imaging device for a spectacle lens, which comprises:

[0324] - a housing comprising a flat surface configured to support an image capture device, the flat surface being provided with an opening of dimensions corresponding to the dimensions of a lens of the image capture device,

[0325] - a base, removable from the case, comprising a flat surface:

[0326] - configured to be positioned inside the case, parallel to the flat surface of the case, and

[0327] - comprising at least one two-dimensional barcode, configured to identify shooting parameters dependent on the image capture method and

[0328] - featuring a catadioptric coating.

[0329] The device of the present invention makes it possible, in particular, to capture an image of a lens using any image capture device and to determine its outline through subsequent digital image processing. The catadioptric coating, in particular, reflects light and thus increases the contrast between the lens outline and the coating.

[0330] The present invention aims to eliminate the need for any moving mechanical parts, such as the probing arm required in a mechanical or optical probe, the camera, or the optical glass to be measured. Therefore, there is no mechanical wear and tear, nor is there any need for maintenance or replacement of parts. Furthermore, image contour determination is accelerated.

[0331] The present invention also aims to overcome the interdependence of elements existing in monolithic configurations, all of which are involved in taking geometric measurements of the ophthalmic lens. In particular, the device of the present invention is suitable for any image capture purpose. Image capture can be performed by opticians equipped with smartphones of different brands and / or models without limiting the accuracy of the measurement.

[0332] The invention increases the contrast of the glass edge compared to prior art methods by enhancing the visibility of the glass edge against the background through the positioning of the glass on a catadioptric surface, with the glass located between the light source and this catadioptric background. The device of the present invention thus offers greater precision than methods using lateral illumination (broad-spectrum or narrow-spectrum, such as lasers), which produce a broadening of the image of the glass edge due to pixel saturation in the camera. Similarly, the precision provided by the device of the present invention is also increased compared to devices using the shadow projected from the glass onto a diffusing frosted surface, which also has the effect of spreading the glass edge across the image obtained due to the diffusion phenomenon produced by the frosted surface.

[0333] Furthermore, the device which is the subject of the present invention takes only an ophthalmic lens as a reference, to the exclusion of any other reference such as: a spectacle frame, a "demonstration" lens or the drawing of a contour pattern.

[0334] Furthermore, the components required for taking geometric measurements of shape and dimensions in a plane do not require precise mechanical adjustment of the elements as in a monolithic configuration, which would necessitate the expertise of a specialist in the manufacture of optical devices. On the contrary, the components involved in the device that is the subject of the present invention can be assembled and implemented by an optician, who is not typically qualified in the manufacture of optical devices.

[0335] Furthermore, the device of the present invention does not require taking an image of the eye, or of any of its elements (pupil, cornea, etc.), or of any other morphological feature of the face or skull of the eyeglass wearer, which are required in other known prior art methods. Unlike other known prior art methods, the present method is not intended to size lenses or frames according to the morphology or eye of an eyeglass wearer.

[0336] Furthermore, the device of the present invention allows for the measurement of the geometric characteristics of sunglass lenses, as it does not require the camera to use patterns placed on the opposite side of the lens from the camera: the lens is not positioned between specific, contrasting geometric patterns on one side and the camera on the other. The catadioptric background is used to enhance contrast only at the edges of the lens; it is not used to evaluate the area inside the lens.

[0337] Additionally, the device of the present invention, designed to determine 2D geometric parameters (shape and dimensions), requires fewer components and constraints, and is therefore simpler to implement, than known prior art devices designed to measure optical parameters or 3D shapes such as refractive index, optical axis or center, optical correction of the lens (vergence), dispersion, aberrations, three-dimensional shape and dimensions, etc. The present method thus distinguishes itself from all these other known prior art methods by its simplicity of design and implementation for the optician using it.

[0338] Finally, the device that is the subject of the present invention does not require that the glass be placed between a light source, for example a light table with its own integrated lighting device, and the camera.

[0339] In some embodiments, the device of the present invention comprises at least three two-dimensional barcodes representing different codes. These embodiments make it possible to identify the orientation of the image during subsequent image processing.

[0340] In some embodiments, the device of the present invention comprises five two-dimensional barcodes representing different codes, four of which are placed at the corners of a rectangle, the fifth being placed on one of the sides of the rectangle.

[0341] These embodiments allow for the identification of various image distortions caused by image capture parameters and dependent on the image capture device. Furthermore, it is possible to determine any rotation angle resulting from incorrect positioning of the image capture device.

[0342] In some embodiments, the base and the casing are made of material that is at least partially opaque.

[0343] These methods ensure that images are captured under controlled conditions, isolated from any external light or lack of light. The camera body, used in conjunction with the smartphone or tablet in this setup, acts as both an insulator and a light diffuser, homogenizing the external light onto the glass and the reflector without producing reflections.

[0344] The controlled lighting environment inside the camera also acts as a "de-missing" device by forcing the user to activate the flash when taking the picture, thus ensuring lighting along the vertical axis of the camera, placing the reflector in optimal conditions to make the edges of the glass stand out in contrast to the background.

[0345] According to a second aspect, the present invention relates to a method for creating a digital file representing the contour of a spectacle lens, which comprises the following steps:

[0346] - capturing a representative image of a glass positioned in a housing assembled to a base of a device that is the object of the present invention, by an image capture means whose lens is placed on the opening of the housing,

[0347] - Determining the image capture parameters depending on the image capture method,

[0348] - Image correction based on predetermined shooting parameters, - Extraction of a curve defining the contour of the glass,

[0349] - definition of a rectangle circumscribing the extracted curve,

[0350] - Calculation of coordinates of a predetermined number of points on the curve.

[0351] Since the aims, advantages and special characteristics of the process which is the subject of the present invention are similar to those of the device which is the subject of the present invention, they are not recalled here.

[0352] Furthermore, thanks to these provisions, it is possible to optically measure the geometric parameters representing the shape and dimensions of the glass in a plane, otherwise known as "tracing," regardless of the image capture method used. Moreover, the image capture method is interchangeable, without requiring contact and / or movement of the camera and / or the glass.

[0353] The measurements obtained by the method of the invention are performed with a precision equivalent to that obtained with an electromechanical and digital probe such as those predominantly used today. These interchangeable cameras are associated with a display screen in the form of a smartphone or tablet, which are themselves interchangeable.

[0354] In some embodiments, the step of determining shooting parameters includes at least one step of comparing the image of each captured two-dimensional barcode with a graphical representation of each two-dimensional barcode and a step of calculating at least one representative value of at least:

[0355] - a homography,

[0356] - a distortion and

[0357] - a rotation.

[0358] These embodiments allow for the determination of any distortions, rotations, and homographies resulting from image capture. The image can then undergo processing to flatten, straighten, and / or rotate it.

[0359] In embodiments, the captured image correction step includes at least one rotational rectification step, one distortion correction step and / or one homographic rectification step of the captured image based on the calculated representative value.

[0360] These implementation methods make it possible to correct distortions related to image capture.

[0361] In some embodiments, the process which is the subject of the present invention further comprises, prior to the step of determining the shooting parameters of the captured image, a step of adapting the contrast of the captured image.

[0362] These embodiments allow for the clear identification of two-dimensional barcode patterns, making them easier to identify and read.

[0363] In embodiments, the process of the present invention further comprises a step of generating a standardized digital file representing the contour of the glass from the coordinates of the calculated points.

[0364] Thanks to these provisions, a standardized file conforming to standards known to a person skilled in the art is obtained.

[0365] In some embodiments, the process of the present invention further comprises a manufacturing phase of a glass frame from the standardized digital file, by additive printing.

[0366] These methods of implementation make it possible to create a replacement frame adapted to a lens that a user is used to, in a very limited time.

Claims

1. 32 DEMANDS 1. A device (10) for standardized image acquisition of a spectacle lens (20), characterized in that it comprises: - a housing (11) comprising a flat surface (14) configured to support an image capture means (30), the flat surface being provided with an opening (15) of dimensions corresponding to the dimensions of a lens (31) of the image capture means, - a base (12), removable from the housing, comprising a flat surface (13): - configured to be positioned inside the case, parallel to the flat surface of the case, and - comprising at least one two-dimensional barcode (17, 18), configured to identify shooting parameters dependent on the image capture method and - comprising a catadioptric coating (16).

2. Device (10) according to claim 1, which comprises at least three two-dimensional barcodes (17, 18) representing different codes.

3. Device (10) according to claim 2, which comprises five two-dimensional barcodes (17, 18) representing different codes, four of which are placed at the corners of a rectangle, the fifth being placed on one of the sides of the rectangle.

4. Device (10) according to any one of claims 1 to 3, wherein the base (12) and the housing (11) are made of at least partially opaque material.

5. Method (40) for creating a digital file representing the contour of a spectacle lens, characterized in that it comprises the following steps: - capture (41) of a representative image of a glass positioned in a housing (11) assembled to a base (12) of a device (10) of which any one of claims 1 to 4 is the subject, by an image capture means (30) whose lens is placed on the opening (15) of the housing, - determination (43) of the shooting parameters of the captured image depending on the image capture method, - correction (45) of the image according to the determined shooting parameters, - extraction (47) of a curve defining the contour of the glass, - definition (48) of a rectangle circumscribing the extracted curve, - calculation (49) of coordinates of a predetermined number of points on the curve.

6. A method (40) according to claim 5, wherein the step (43) for determining shooting parameters includes at least one step (44) for comparing the image of 33 each two-dimensional barcode captured with a graphical representation of each two-dimensional barcode and a calculation step (44) of at least one representative value of at least: - a homography, - a distortion and - a rotation.

7. Method (40) according to claim 6, wherein the correction step (45) of the captured image comprises at least one rotational rectification step (46), a distortion correction step (46) and / or a homographic rectification step (46) of the captured image as a function of the calculated representative value.

8. Method (40) according to any one of claims 5 to 7, which further comprises, prior to the step of determining (43) the shooting parameters of the captured image, a step of adapting (42) the contrast of the captured image.

9. Method (40) according to any one of claims 5 to 8, further comprising a generation step (50) of a standardized digital file representing the contour of the glass from the coordinates of the calculated points.

10. Method (40) according to any one of claims 5 to 9, which further comprises a manufacturing phase (90) of a glass frame from the standardized digital file, by additive printing.

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