Method of manufacturing an ophthalmic lens

Abstract

The invention relates to a method of manufacturing an ophthalmic lens (10) to be mounted into a frame, comprising: - a step of acquiring an optical prescription for a future wearer of the ophthalmic lens and information about the ophthalmic lens and / or said future wearer and / or said frame, - a step of calculating surface machining instructions for machining at least one optical face (11) of the ophthalmic lens, said surface machining instructions being determined so that the ophthalmic lens, once surface-machined, meets said optical prescription, and - a surface machining step, during which said at least one optical face of the ophthalmic lens is surface-machined according to said surface machining instructions. According to the invention, during said calculating step, said surface machining instructions are calculated so that said optical face of the ophthalmic lens, once surface-machined, comprises a mark (20) resulting from said surface machining step and forming a code associated with said information.

Description

Technical Field

[0001] This invention relates to ophthalmic lenses intended for installation in eyeglass frames.

[0002] More specifically, the present invention relates to a method for manufacturing ophthalmic lenses, a process for inspecting ophthalmic lenses manufactured by the method, and an ophthalmic lens manufactured by the method. Background Technology

[0003] Preparing an ophthalmic lens for mounting in an eyeglass frame chosen by the wearer involves the following five main operations:

[0004] - The ophthalmic lens is shaped into a standard form (at the end of this process, the lens is called a "semi-finished lens").

[0005] - Machining one of the optical surfaces of an ophthalmic lens so that its optical power equals the desired optical power (using the term "surface finishing operation").

[0006] - Obtain the outline of one of the lens rims or one of the lenses of the eyeglass frame selected by the customer (the future wearer of the eyeglass frame).

[0007] - Centering the lens involves properly positioning and orienting the contour on the lens so that, once assembled, the lens will be centered relative to the pupil of the wearer's corresponding eye.

[0008] - The lens is edged, which involves cutting the lens along the centered contour so that the lens mechanically and satisfactorily matches the shape of the selected frame while performing its designed optical functions as much as possible.

[0009] Applying markings to ophthalmic lenses can be very useful, for example, to identify the lens during its manufacturing process.

[0010] Many documents describe the apparatus and methods for applying this label.

[0011] For example, document US 9625743 describes a lens with a front surface onto which a QR code is printed directly. This QR code stores information in digital form that can be used to machine the lens along the contour corresponding to one of the frames. In a variant, this QR code is printed on a sticker affixed to the lens.

[0012] The main drawback of this solution is that printing QR codes requires specific tools (ink pad or printer), which is both expensive and time-consuming.

[0013] Furthermore, lenses are typically coated, for example, with an anti-reflective coating, before edging. During this coating process, there is a risk that the markings may be covered by the coating, causing them to lose their intended function. Summary of the Invention

[0014] It is therefore an object of the application to provide a solution to apply a marking on a lens at a lower cost.

[0015] According to the application, the above-mentioned object is achieved by means of a method for manufacturing an ophthalmic lens, the method comprising:

[0016] - a step of acquiring an optical prescription for a future wearer of the ophthalmic lens and information about the ophthalmic lens and / or said future wearer and / or said frame,

[0017] - a step of calculating surface machining instructions for machining at least one optical face of the ophthalmic lens, said surface machining instructions being determined so that the ophthalmic lens, once surface-machined, meets said optical prescription, and

[0018] - a surface machining step during which said at least one optical face of the ophthalmic lens is surface-machined according to said surface machining instructions,

[0019] wherein, during said calculating step, said surface machining instructions are calculated so that said optical face of the ophthalmic lens, once surface-machined, comprises a marking, the marking resulting from said surface machining step and forming a code associated with said information.

[0020] In other words, the marking of the lens is done during the surface machining operation, so that it does not require any additional tool, thereby reducing the cost.

[0021] This solution also reduces the complexity of the operation and does not require any additional time to be performed.

[0022] Another advantage of this solution is that the marking is not visible to the user, so that it can be positioned inside the contour of the lens once edged, that is to say in the part of the semi-finished lens that will not be removed during the edging operation. This marking can therefore also be used after the manufacture of the eyeglasses, for example as a kind of warranty.

[0023] Other advantageous features of the application are as follows:

[0024] - said calculating step comprises a sub-step of determining an intermediate file from said optical prescription, a sub-step of encoding said acquired information, and a sub-step of determining said surface machining instructions from said intermediate file and the encoded information,

[0025] - the marking comprises an array of discontinuous areas, the form and / or the position of which form said code,

[0026] - each discontinuous region is formed by a microlens whose optical power is different from the optical power of said optical face of the ophthalmic lens,

[0027] - the mark comprises an array of continuous regions, the form of which and / or their position form said code,

[0028] - the array of continuous regions stores said information in a digital form,

[0029] - said information comprises one of the following elements: lens serial number, wearer information (for example wearer identity), optical prescription, lens optical information, lens model, lens manufacturer identification,

[0030] - the method comprises the steps of acquiring the shape of the contour along which the ophthalmic lens is to be edged, and centering the acquired contour with respect to the ophthalmic lens, said mark being positioned inside said contour.

[0031] The application also relates to a method of controlling an ophthalmic lens manufactured by the manufacturing method described above, comprising the steps of:

[0032] a) capturing a raw image of at least one portion of said ophthalmic lens showing said mark, and

[0033] b) processing the raw image acquired in step a) in order to decode the information associated with the code formed by said mark.

[0034] Preferably, this method comprises a step c) of verifying the ophthalmic lens according to the decoded information.

[0035] The application also relates to an ophthalmic lens comprising two optical faces and adapted to be mounted into a frame in order to be worn by a future wearer, wherein at least one of said two optical faces comprises a mark forming a code associated with information about the ophthalmic lens and / or said future wearer and / or said frame and resulting from an operation of surface processing of the whole of said optical face of the ophthalmic lens.

[0036] Other advantageous features of the lens are as follows:

[0037] - the mark comprises an array of discontinuous regions, the form of which and / or their position form said code,

[0038] - each discontinuous region is formed by a microlens whose optical power is different from the optical power of said optical face of the ophthalmic lens,

[0039] - the mark comprises an array of continuous regions, the form of which and / or their position form said code,

[0040] - the array of continuous regions stores said information in a digital form. Attached Figure Description

[0041] The following description, with reference to the accompanying drawings and by way of non-limiting examples, clarifies the scope of the invention and the ways in which it is practiced.

[0042] In the attached diagram:

[0043] - Figure 1 It is a view of an image of a surface-processed lens acquired by a light sensor.

[0044] - Figure 2 yes Figure 1 Detailed view of Area II,

[0045] - Figure 3 yes Figure 2 The same source view as the view shown, and

[0046] - Figure 4 It is a table showing the correspondence between letter codes and Braille codes. Detailed Implementation

[0047] The present invention relates primarily to a method of manufacturing an ophthalmic lens that enables the lens to perform an optical function for correcting optical defects in a patient who is a future wearer of eyeglasses comprising a frame and the ophthalmic lens.

[0048] In summary, this manufacturing method includes a first operation of obtaining an optical prescription F1 for a future wearer, the optical prescription being provided by the wearer's optometrist.

[0049] This manufacturing method includes a second operation of shaping the material to obtain a semi-finished lens. This semi-finished lens has a standard shape and therefore does not exhibit the desired power derived from the optical prescription F1.

[0050] The third operation involves machining at least one of the optical surfaces of the semi-finished lens using machining tools, such that the latter's optical power equals the required optical power. This operation is referred to as the "surface finishing operation." In this step, the surface-finished lens 10 includes two optical surfaces 11, 12 and an edge 13 having a circular profile C1 around the principal axis A1 (see...). Figure 1 ).

[0051] The fourth operation is to machine the edge of the lens so that the edged lens has a profile C2 that matches the shape of the corresponding frame rim. This operation includes obtaining the shape of the frame rim profile, positioning this profile C2 in the lens reference system, and cutting the lens along this profile C2.

[0052] Then, during the final operation, the ground lenses and frames are assembled into a pair of glasses.

[0053] This invention mainly relates to the third operation.

[0054] This operation can be performed using a CNC freeform surface machining machine. The term "CNC" refers to all the hardware and software used to provide motion commands for all parts of the surface machining machine.

[0055] This type of surface finishing machine is well-known to technicians.

[0056] We can only explain that such a machine typically includes a spindle that carries surface processing tools, a support that holds semi-finished lenses, and a computing and control command unit (hereinafter referred to as the "computing unit") equipped with a data processing system that includes a microprocessor equipped with memory that allows it to load and store software packages (also known as computer programs) that, when executed in the microprocessor, enable the implementation of the manufacturing method.

[0057] According to the present invention, the manufacturing method includes not only obtaining an optical prescription F1 for a future wearer of the ophthalmic lens, but also obtaining information F2.

[0058] This information F2 relates to ophthalmic lenses and / or future wearers and / or frames. The purpose of this acquisition is to store this information F2 on the lens by means of markings 20 machined on the lens during surface processing operations (i.e., by means of surface processing tools).

[0059] This information F2 may include one or more data. For example, this information may include one or more of the following data:

[0060] - Lens serial number,

[0061] - Wearer information (wearer's identity, age, lens wearing history, etc.)

[0062] - Optical prescription F1,

[0063] - Lens optical characteristics (materials, optical refractive index, etc.)

[0064] - Lens model

[0065] - Lens batch identification (when lenses of similar shape are processed in batches).

[0066] - Lens manufacturer's logo...

[0067] In the following example, information F2 includes only the lens serial number. This lens serial number (here, "00312") consists of five digits.

[0068] Based on the base curve of the semi-finished lens, prescription F1, and information F2, the calculation unit performs the step of calculating surface processing instructions F4 for machining at least one of the optical surfaces 11 of the ophthalmic lens 10.

[0069] Here we can assume that only the front side 11 needs to be machined. However, in a variant, only the back side can be machined. In another variant, both sides can be machined.

[0070] In the non-limiting example disclosed herein, this calculation step includes three sub-steps.

[0071] The first sub-step includes determining the intermediate document F3 based on the optical prescription F1, thereby taking into account the base curve of the semi-finished lens.

[0072] This intermediate file F3 is calculated using a well-known method, in such a way that if the lens is machined using this file, it will take on a shape that enables it to perform the optical functions it is designed to perform.

[0073] Then, complete this intermediate file F3.

[0074] Therefore, during the second sub-step, information F2 is encoded.

[0075] In our example, information F2 is encoded using Braille codes.

[0076] The correspondence table between each letter and its associated code is as follows: Figure 4 As shown. According to this Braille code, each letter can be encoded with six dots, and each number can be encoded with four dots.

[0077] In our example, the information F2 consists of five digits. Therefore, in our example, each digit is encoded using four points distributed at the corners of a square. Figure 4 As shown, each point can be mathematically represented by the coefficient "1" of the 2-2 matrix (no points are represented by empty coefficients).

[0078] In variations and more general ways, we can use a 2-3 matrix to represent points that encode a letter or a number.

[0079] In our example, for simplicity, we can think of it as follows: to encode information F2, the computational unit generates five 2-2 matrices and derives from them... Figure 3 The image shown comprises five components 21-25, each of which is associated with one, two, three, or four points, and each is associated with one of the 2-2 matrices.

[0080] Each component is distributed in a rectangle with a height of Δ2 = 1.7 mm and a width of Δ1 = 1.1 mm, and two adjacent components are spaced δ1 = 0.5 mm apart.

[0081] Once machined onto the front 11 of the lens, these components form an image known as “mark 20”.

[0082] Finally, the third sub-step involves determining the surface processing instructions F4 based on the intermediate file F3 and the encoded information. More specifically, the image is embedded in the intermediate file F3 such that once surface processed, the lens includes markings 20.

[0083] In other words, the surface processing instruction F4 is calculated such that once the optical surface 11 of the ophthalmic lens 10 is surface-processed, it includes a mark 20 generated by the surface processing step and forms a code associated with the information F2.

[0084] Then, the final step involves surface processing of the optical surface 11 of the ophthalmic lens 10 according to this surface processing instruction F4.

[0085] Then, the surface processing instruction F4 is sent to the surface processing machine, and the front side 11 of the lens is machined according to this instruction F4.

[0086] Because the same tool is used, the mark 20 is formed on the front side 11 of the lens, simultaneously with the rest of the front side 11.

[0087] In the variant where only the back side is surface-finished, mark 20 is of course machined onto this back side.

[0088] In another variant where both surfaces are surface-finished, mark 20 can be machined on either or both surfaces of the lens.

[0089] Marker 20 can be of any shape, provided that the embedded code can be decoded by a decoding device.

[0090] exist Figure 1 The first embodiment is illustrated in the figure. In this embodiment, the marker 20 comprises a discontinuous array of regions whose form and / or position form the code.

[0091] The discontinuity in height of each discontinuous region along its contour at the point on the front 11 (the height is measured along the main axis A1): when the front is viewed in a cross section in a plane that includes the main axis A1 and passes through the center of one of the discontinuous regions, the representative curve of the front 11 in this plane presents corner points on each side of the discontinuous region.

[0092] In other words, a discontinuous region can be defined as a region bounded by an edge (here, a circle) or as a region along the contour where the optical power of the lens changes discontinuously.

[0093] In the example shown in the figure, each discontinuous region is formed by microlenses 21A-25A.

[0094] Each microlens 21A-25A has a circular profile, but in variations, this profile can be square, elliptical, or other shapes.

[0095] Each microlens 21A-25A has an optical power different from that of the annular region surrounding the front 11 (which produces a discontinuity).

[0096] The power of the microlens needs to be small enough so that the wearer will not perceive a difference in power between the microlens and the annular region when wearing the lens, but at the same time, the difference must be large enough to be detected by the decoding device.

[0097] The absolute value of the difference between the optical power of each microlens and the optical power of the corresponding annular region is preferably greater than 1.5 diopters. In a variant, if the device used for decoding mark 20 is capable of performing very accurate measurements, a difference of less than 1.5 diopters can be used.

[0098] In another embodiment not shown in the figure, the mark 20 may include a continuous array of regions whose form and / or position form the code.

[0099] We can provide an example. In this example, area 11 on the front of the lens includes a continuous change in optical power. These changes are greater than those of the rest of the lens. Within this area, the optical power is presented at high and low levels. The high level may correspond to the black squares of a QR code (or the lines of a barcode), while the low level may be associated with the white squares of a QR code. In our example, these levels are 0.1 mm apart.

[0100] In this example, the contiguous area array stores information F2 in digital form. The significance of this is that the QR code is associated with binary code that can be used to store information F2, or with an identifier associated with this information. For example, the QR code could store the address of the database record where information F2 is stored.

[0101] Preferably, in both embodiments, the mark 20 is positioned inside the contour C2.

[0102] Because of this feature, mark 20 is retained on lens 10 after the edging operation, so that information F2 can be used not only for the edging operation, but also for mounting the lens to the frame rim and for after-sales service.

[0103] To avoid discomfort to the wearer, mark 20 is positioned in the upper part of the lens.

[0104] For this reason, the marker is positioned at a distance from contour C2 less than 50% of the minimum distance between the geometric center of the contour and contour C2. This geometric center (also known as the "box center") is defined here as the center of the horizontal rectangle circumscribed by contour C2.

[0105] In this manufacturing process step, the ophthalmic lens 10 includes a mark 20 that forms a code associated with information F2 and is generated by an operation of surface finishing the entire front surface 11.

[0106] Due to this manufacturing process, the wearer cannot see mark 20 when wearing his glasses. However, this mark 20 must be visible to users who want to obtain information F2 (such as opticians).

[0107] To read mark 20, the user can use a specific optical device or a non-specific device equipped with a light sensor.

[0108] The specific optical device may be, for example, the fabrication apparatus disclosed in document US 2010228375. In practice, this apparatus includes a light sensor and an image processing unit suitable for detecting the mark 20.

[0109] The non-specific device can be a mobile telecommunications device, such as a portable desktop computer, mobile phone, or tablet computer, which includes a light sensor and an image processing unit.

[0110] In both embodiments, the image processing unit must be programmed to be adapted to decode information F2.

[0111] More precisely, the image processing unit must be programmed to perform a method of controlling the ophthalmic lens 10 by implementing the following steps: acquiring (by means of a light sensor) an original image Img1 of at least a portion of the ophthalmic lens 10 displaying the mark 20 (see the first step). Figure 1 The second step involves processing this original image Img1 to decode the information F2 associated with the Braille code formed by the mark 20.

[0112] The second step includes the following sub-steps:

[0113] - Detect the position of the contour of each microlens 21A-25A.

[0114] - Components 21-25 that identify the microlenses, each of which is associated with a number according to a Braille code.

[0115] - Determine the number and location of microlenses for each component.

[0116] - Generate a binary matrix whose coefficient is 1 if the associated component includes a microlens at the corresponding location, and 0 otherwise.

[0117] - exist Figure 4 Read the numbers associated with this matrix from the table.

[0118] - Derive information F2 from it.

[0119] Once the F2 information is decoded, it can be used in various ways.

[0120] For example, if information F2 includes the shape of contour C2, this information can be used in the edging process to cut the surface-finished lens along this contour C2.

[0121] In another example, information F2 can be used during the third step of verifying ophthalmic lens 10 in after-sales service.

[0122] More specifically, users can verify the authenticity of the glasses lenses by scanning mark 20 with their mobile phones and sending the read information F2 to a central server. The central server will then send a message in response confirming the lens's authenticity. In this example, the encoded serial number serves as the warranty number. Therefore, wearers do not need to worry about losing their warranty card.

[0123] We note that, preferably, the marking is completed on the semi-finished lens, then the lens is edged along the final contour, and preferably any treatment is then applied to the lens. Therefore, the marking is completed on the overall core of the lens.

Claims

1. A method of manufacturing an ophthalmic lens (10) to be mounted in an eyeglass frame, comprising: - The steps of obtaining an optical prescription (F1) for the future wearer of the ophthalmic lens (10) and information (F2) about the ophthalmic lens and / or the future wearer and / or the frame. - A calculation step, wherein the calculation step calculates a surface machining instruction (F4) for machining at least one optical surface of the ophthalmic lens (10), the surface machining instruction (F4) being determined such that the ophthalmic lens (10) satisfies the optical prescription (F1) once surface-machined, and - A surface finishing step, during which at least one optical surface of the ophthalmic lens (10) is surface-finished according to the surface finishing instruction (F4). The feature is that, during the calculation step, the surface processing instruction (F4) is calculated such that the optical surface of the ophthalmic lens (10) includes a mark (20) once surface-processed, the mark being generated by the surface processing step to form a code associated with the information (F2), and the mark (20) is formed simultaneously with the rest of the optical surface due to the use of the same tools.

2. The manufacturing method according to claim 1, wherein, The calculation steps include a sub-step of determining an intermediate document (F3) based on the optical prescription (F1), a sub-step of encoding the acquired information (F2), and a sub-step of determining the surface processing instructions (F4) based on the intermediate document (F3) and the encoded information.

3. The manufacturing method according to claim 1, wherein, The mark (20) comprises an array of discontinuous regions whose form and / or position form the code.

4. The manufacturing method according to claim 3, wherein, Each discontinuous region is formed by a microlens (21A - 25A) with an optical power different from that of at least one optical surface of the ophthalmic lens (10).

5. The manufacturing method according to claim 1, wherein, The marker comprises a continuous array of regions whose form and / or position form the code.

6. The manufacturing method according to claim 5, wherein, The continuous region array stores the information in digital form.

7. The manufacturing method according to claim 1, wherein, The information includes one of the following elements: - Lens serial number, - Wearer information - Optical prescription, - Lens optical information, - Lens model - Lens manufacturer's logo.

8. The manufacturing method according to claim 1, comprising the following steps: - Obtain the shape of the contour of the ophthalmic lens to be edged, and - Center the acquired contour relative to the ophthalmic lens. Furthermore, the mark (20) is positioned inside the contour.

9. A method for controlling an ophthalmic lens manufactured by the manufacturing method according to any one of claims 1 to 8, comprising the following steps: a) Capture an original image (Img1) of at least a portion of the ophthalmic lens (10) displaying the mark (20), and b) Process the original image (Img1) obtained in step a) in order to decode the information associated with the code formed by the mark (20).

10. The control method according to claim 9, including step c) verifying the ophthalmic lens (10) based on the decoded information.

11. An ophthalmic lens (10) obtained by the manufacturing method according to claim 1, comprising two optical surfaces and adapted for mounting in a frame for wear by a future wearer, wherein, At least one of the two optical surfaces includes a mark (20) that forms a code associated with information about the ophthalmic lens (10) and / or the future wearer and / or the frame and is generated by an operation of surface processing of the entire optical surface of the ophthalmic lens (10).

12. The ophthalmic lens (10) according to claim 11, wherein, The mark (20) comprises an array of discontinuous regions whose form and / or position form the code.

13. The ophthalmic lens (10) according to claim 12, wherein, Each discontinuous region is formed by a microlens, the optical power of which differs from the optical power of the optical surface of the ophthalmic lens.

14. The ophthalmic lens (10) according to claim 11, wherein, The mark (20) comprises a continuous array of regions whose form and / or position form the code.

15. The ophthalmic lens (10) according to claim 14, wherein, The continuous region array stores the information in digital form.

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