Method for determining the shape of the groove in the eyeglass frame rim

Abstract

This invention relates to a method for determining the shape of a groove (16) in an eyeglass frame rim (11), the method comprising: - obtaining the shape of a longitudinal profile of the groove; - calculating or indicating a cross section (S) to be probed along said longitudinal profile. j The position (θ) j The steps include: ) and - moving the moving detector within the slot to measure the cross section (S). j The steps of detecting at least a portion of )

Description

Technical Field

[0001] This invention relates generally to the field of eyeglass manufacturing, and more specifically to the machining of ophthalmic lenses.

[0002] More specifically, the present invention relates to a method for determining the shape of a groove in an eyeglass frame rim, an operation that is a prerequisite for edging the lens to be mounted in the rim. Background Technology

[0003] The technical aspect of an optician's work involves fitting a pair of eyeglass lenses into a frame chosen by the customer. This technical aspect can be divided into four main procedures:

[0004] - Obtain the shape of the groove in each of the two lens rims of the eyeglass frame chosen by the future wearer, i.e., obtain the shape of the groove extending inside the lens rims around the frame.

[0005] - Centering each ophthalmic lens involves determining the lens's reference frame using centering marks set on the lens, and then appropriately positioning the previously obtained lens rim profile within the lens's reference frame. This ensures that once the lens is edged to this profile and then installed in the lens frame, it is correctly positioned relative to the customer's corresponding eye and best fulfills the optical functions designed for this purpose.

[0006] - Each lens is blocked, including attaching a blocking accessory to the lens, so that the lens can be easily removed from the centering station and then joined in the edging station without losing the reference frame.

[0007] - Grind the edges of each lens, including machining the lens into the previously centered profile.

[0008] This acquisition operation is of particular interest here.

[0009] This procedure is usually performed by the optician using a reading device.

[0010] Such a reading device typically includes a frame support, a detector movable relative to the support, and an electronic and / or computer unit for controlling the position of the detector relative to the support. Therefore, the electronic and / or computer unit is adapted to acquire the coordinates of multiple points detected in the grooves around each lens ring of the frame, and then derive control setpoints for machining tools based on these coordinates.

[0011] Optimized reading instruments capable of measuring the cross-sectional shape of the groove are also known from the art (see, for example, document FR 2751433). Such measurement is useful for creating a bevel around the lens suitable for inserting the lens ring.

[0012] This measurement is usually performed at the bottom of the mirror ring because it is easier to detect the cross-section of the bevel in that area.

[0013] However, this reading operation is not accurate enough to produce a perfect lens bevel, thus posing a risk of mechanical interference between the lens and the frame. Summary of the Invention

[0014] In this context, the present invention provides a method for determining the shape of a groove in an eyeglass frame rim, the rim comprising a front and a back, with a temple attached to the back side, the method comprising:

[0015] - The steps to obtain the shape of the longitudinal contour of the slot, and

[0016] - The step of probing at least a portion of at least one cross-section of the slot by moving a mobile detector within the slot.

[0017] Prior to the detection step, the method includes a step of calculating or indicating the orientation of the cross-section to be detected along the longitudinal contour, and

[0018] In the detection step, only the rear portion of the cross section is detected, and the rear portion is closer to the back of the lens ring than the rest of the cross section.

[0019] Thanks to this invention, a better approximation of the 3D shape of a groove can be determined by using a simple detection device to read the shape of at least the most characteristic cross-section of what is considered the groove shape.

[0020] Preferably, at least two cross sections are read.

[0021] For example, the present invention enables users of the forming apparatus to measure or estimate the height difference between the front and back of the groove in a small number of cross sections of each lens ring, so that the mating bevel can be machined based on these height differences.

[0022] This operation can be performed without special tools and does not take much time.

[0023] The measurement results are then input into the forming device, which machines the bevel of the lens into a non-uniform cross-section, thereby avoiding mechanical interference between the lens and the frame.

[0024] More precisely, the height difference between the front and rear edges of the groove is typically observed to vary continuously around the lens ring. Therefore, the height difference in each section of the lens ring can be easily estimated based on measurements taken at three or more different sections of the lens ring.

[0025] Furthermore, the height difference can be measured between the front and rear edges of the mounting groove where obstructions (temples, bridge, nose pads) form on the lens rim. Correspondingly, since these obstructions typically deform the lens rim, their presence affects the measured height difference. Therefore, by taking this difference into account during lens machining, the risk of interference between the lens and the obstruction can be potentially reduced. This is particularly advantageous because such interference can deform the frame, exert mechanical stress on the lens, or even prevent the lens from being installed in the rim.

[0026] This process ensures that the geometry of the processed lens will not cause any deformation of the front of the frame due to interference between the lens and the rear area.

[0027] Other preferred features of the present invention are as follows:

[0028] - The operator manually points out the location of the cross section through a human-machine interface.

[0029] - The position of the cross section is automatically calculated based on the shape of the longitudinal profile.

[0030] - After the step of calculating or indicating the orientation of the cross section, the detector moves automatically without sliding directly along the slot to reach that orientation.

[0031] - After the step of calculating or indicating the orientation of the cross section, the detector moves automatically to reach that orientation by sliding along the slot.

[0032] - The longitudinal profile includes four angular sectors of equal extent, including the upper angular sector, the lower angular sector, the nasal angular sector, and the temporal angular sector.

[0033] - The cross section is located in the nasal angle sector or the temporal angle sector.

[0034] - During the calculation or indication step, calculate or indicate the positions of at least two sections of the groove.

[0035] - During the detection step, the at least two cross sections are detected by moving the mobile detector in the slot between two different planes.

[0036] - Calculate the shape of at least one undetected section of the groove based on the shape of the detected section.

[0037] -The entire 3D shape of the groove is calculated based on the shape of the probed cross section, for example by interpolation.

[0038] - A single cross-section of the inclined plane is probed, and it is assumed that the shape of each cross-section of the groove is the same as the shape of the probed cross-section.

[0039] -If the detector is only able to detect a portion of the cross section, the shape of the remaining portion of the cross section is calculated based on the shape of the detected portion.

[0040] The steps of obtaining the shape of the longitudinal profile of the groove and probing at least a portion of the cross section are performed by a reading device. Between these two steps, the position of the frame in the reading device is modified such that the detector can probe the entire cross section during the step of probing the cross section.

[0041] - The method includes the step of storing data related to the shape of the longitudinal profile and / or the shape of the cross section in a register, in which each entry is associated with an eyeglass frame model or model category.

[0042] - The step of obtaining the shape of the longitudinal profile of the groove is performed by a reading device during the probing operation, and wherein the step of probing at least a portion of the cross section is performed during an operation different from the probing operation.

[0043] - The lens ring includes a front and a rear, with a temple attached to the rear side. During the step of probing at least a portion of the cross section, only the rear portion of the cross section is probing, which is closer to the rear of the lens ring than the rest of the cross section.

[0044] The present invention also relates to a method for machining a lens to be mounted in an eyeglass frame, the method comprising:

[0045] - A first operation, which includes performing the method as defined above by means of a reading device.

[0046] - A second operation, which includes determining grinding parameters based on the shape of the longitudinal profile and the shape of each probed section, and

[0047] - A third operation, comprising grinding the lens with an edging machine according to the edging parameters to form a bevel along at least a portion of the lens's contour.

[0048] The grinding parameters cause the shape of at least one specific cross-section of the bevel to depend on the cross-section of the groove being probed.

[0049] Preferably, the inclined surface includes a front side and a rear side, wherein the height of the front side is different from the height of the rear side in the specific cross section, and the difference is determined according to the shape of the cross section detected by the groove.

[0050] Preferably, the grinding parameters cause the shape of the specific cross-section of the bevel to depend on one of the following data:

[0051] - The angle between the front and rear sides of the groove embedded in the cross-section of the probe.

[0052] - The depth of the groove on the cross-section of the probe.

[0053] -The inclined plane is located longitudinally within the thickness of the lens frame on the cross-section of the probe.

[0054] - The skew angle (i.e., its slope) of the groove in the cross section of the probe, for example, relative to the average plane of the mirror ring. Attached Figure Description

[0055] The following description, with reference to the accompanying drawings and by way of non-limiting examples, makes clear the scope of the invention and the ways in which it may be practiced.

[0056] In the attached diagram:

[0057] - Figure 1 It's a 3D model of an eyeglass frame with lenses.

[0058] - Figure 2 yes Figure 1 A three-dimensional diagram of a portion of the lens rim of an eyeglass frame.

[0059] - Figure 3 It is a 3D image of an ophthalmic lens.

[0060] - Figure 4 yes Figure 3 A stereoscopic image of a portion of an ophthalmic lens.

[0061] - Figure 5 It is a three-dimensional drawing of an instrument used to read the contours of eyeglass frame rims, in order to Figure 1 The eyeglass frame is shown in the first configuration, mounted therein.

[0062] - Figure 6 yes Figure 5 A detailed view of a part of the appliance, to Figure 1 The eyeglass frames are shown in a second configuration.

[0063] - Figure 7 yes Figure 1 A view of the lens rim of the eyeglass frame and four cross-sections of the lens rim.

[0064] - Figure 8 yes Figure 1 The cross-section of the lens rim of the eyeglass frame and Figure 3 A cross-sectional view of an ophthalmic lens.

[0065] - Figure 9 It is joined to Figure 1 A view of the detector within the lens rim of the eyeglasses frame.

[0066] - Figure 10 Is Figure 1 A view of two contours detected inside the lens rim of the eyeglass frame, and

[0067] - Figure 11 yes Figure 3 A cross-sectional view of the edge of an ophthalmic lens. Detailed Implementation

[0068] Figure 1 A spectacle frame 10 with two lens rings 11 (or frames) is shown. Each lens ring is used to receive an ophthalmic lens and is positioned in front of the corresponding eye of the wearer when the frame is worn. The two lens rings 11 are connected together by a bridge 12. Each lens ring is also fitted with a nose pad 13 suitable for resting on the wearer's nose and a temple 14 suitable for resting on the wearer's ear. Each temple 14 is hinged to the corresponding lens ring by a hinge 15.

[0069] like Figure 2 As shown, each lens rim 11 of the eyeglass frame 10 has an inner side surface including an inner engagement groove (commonly referred to as a groove 16). In this embodiment, the groove 16 presents a V-shaped axial cross-section having a front side surface 16A, a rear side surface 16B, and a bottom edge 17. The groove is defined by a front edge 18 and a rear edge 19. In variations, the groove can naturally have another shape; for example, the groove can be arc-shaped.

[0070] For each mirror ring 11, a mean plane P1 and a mean axis A1 are defined. The mean plane P1 is defined as the plane closest to the set of points constituting the bottom edge 17 of the groove 16. The coordinates of this plane can be obtained, for example, by applying the least squares method to the coordinates of multiple points on the bottom of the groove. The mean axis A1 is defined as an axis perpendicular to the mean plane P1 and passing through the centroid (center of mass) of the points constituting the bottom edge 17 of the groove 16.

[0071] The cross section S of each lens ring 11 j Defined as a lens ring 11 and an orientation angle θ about an average axis A1. j plane P2 j The cross-section.

[0072] Each section S j Limited lens section P j In this embodiment, each cross-section P j Including the front edge 18 and the back edge 19 in plane P2 j The two parallel line segments corresponding to the traces in the middle, and the front side 16A and rear side 16B in plane P2 jThe two V-shaped line segments corresponding to the trace in the image.

[0073] Mirror ring section P j The shape can vary around the contour of each lens ring 11.

[0074] In particular, such as Figure 7 and Figure 8 As shown, the front edge 18 and the back edge 19 are respectively separated from the average axis A1 by a first distance and a second distance. The difference between these distances is called the offset height G. j .

[0075] Offset height G j It can be limited to the front edge 18 in the section S under consideration. j The maximum distance between the trace and the average axis A1 and the second largest distance between the trace and the rear edge 19 in the section S j The difference between the maximum distance between the trace in the curve and the average axis A1.

[0076] However, here, the offset height G j Preferably, the measurement is not radially relative to the average axis A1, but along the bisector direction F. j Measurement. In practice, the curvature of the front lens should be approximately equal to the curvature of the frame (that is, parallel to the bisector direction F). j ).

[0077] Since the nose pad 13 and hinge 15 are fastened to the rear edge 19, the presence of the nose pad and hinge may affect the shape of that rear edge. Therefore, it can be understood that the nose pad 13 and hinge 15 may affect the offset height G. j It has an impact. For example... Figure 2 As shown, the groove 16 in each section S j The opening angle D in j The angle is defined as the distance between the trace of the front side 16A and the trace of the rear side 16B.

[0078] The eyeglass frame 10 can also be chamfered. Therefore, the groove 16 is skewed, i.e., twisted. Therefore, as... Figure 2 As shown, each cross section S of the groove 16 j It exhibits its own tilt angle. This tilt angle varies along the groove 16 at each section S. j The angle C used in this context is called the deflection angle. j To quantify. Skew angle C j The angle bisector F corresponding to slot 16 j The angle between the axis perpendicular to the average axis A1 in the average plane P1 of the mirror circle 11.

[0079] like Figure 3 and Figure 4As shown, the ophthalmic lens 20 has a front optical surface 21, a rear optical surface 22, and an edge surface 23.

[0080] Ophthalmic lenses 20 have optical and geometric features.

[0081] Among its optical characteristics, the spherical diopter of the lens is specifically defined. Spherical diopter is a quantity that characterizes and quantifies the "magnifying" effect of a lens on a beam of light under consideration. The point where the magnifying effect of the lens is zero (i.e., for a lens with only spherical diopter, the point where the incident and transmitted rays have the same axis) is called the optical center.

[0082] The edge surface 23 of the lens initially presents a circular outline. Figure 3 However, the lenses are designed to be shaped to match the corresponding rims of the eyeglass frame 10 so that the lenses can be engaged within the rims.

[0083] like Figure 4 As shown, the lens is more precisely designed to have a joining ridge 26 (or bevel) defined by a front edge 28 and a rear edge 29 on its edge surface 23. The joining ridge 26 described herein has a V-shaped cross section, with a top edge 27 extending along the edge surface 23 of the lens, and front side surfaces 26A and rear side surfaces 26B on either side of the top edge 27.

[0084] In the variation, the edge surface of the ophthalmic lens can be formed to have a cross-section with a certain other shape.

[0085] Just like lens ring 11, a mean plane and a mean axis A2 can be defined for the lens. The mean plane can be defined as a plane orthogonal to the optical axis of the lens. The mean axis A2 can be defined as an axis perpendicular to the mean plane and passing through the centroid of the point that forms the top edge 27 of the inclined plane 26.

[0086] Axial section S' of ophthalmic lens 20 i The lens is defined as being aligned with the optical axis A2 and forming an orientation angle θ' about the optical axis. i The cross section of half-plane P3.

[0087] Each axial section S' of ophthalmic lens 20 i Limited lens section P' i In this example, each cross-section P' i This includes two parallel line segments corresponding to the traces of the front edge 28 and the rear edge 29 in the half-plane P3, and two V-shaped line segments corresponding to the traces of the front side 26A and the rear side 26B in the half-plane P3.

[0088] In the following text, when the axial section S' of lens 20 i angular position θ' iThe cross section S of the frame 10 j angular position θ j When they are the same, their cross sections are said to be "corresponding".

[0089] To implement the method of the present invention, a shape reading device is required. This shape reading device includes apparatus well known to those skilled in the art and does not specifically constitute the subject matter of the described invention. For example, the shape reading device described in patent EP 0750 172 can be used.

[0090] Figure 5 This is an overall view of the shape reading device 100 presented to its user. The device has a top cover 101 that covers the entire device except for the top central portion in which the eyeglass frame 10 is placed.

[0091] The shape reading device 100 is mainly used to read the shape of the bottom edge of the groove of each lens ring 11 of the eyeglass frame 10.

[0092] Figure 5 The illustrated reading device 100 has a set of two chucks 102, wherein at least one of the chucks 102 is movable relative to the other, such that the chucks 102 can move toward or away from each other to form a clamping device. Each chuck 102 is also provided with two clamping members, each clamping member consisting of two studs 103, which are movable to clamp the eyeglass frame 10 between them, thereby preventing the eyeglass frame from moving.

[0093] Structure 104 can be seen in the visible space left by the central opening at the top of cover 101. A plate (not visible) can be translated along the transfer axis A3 on structure 104. A turntable 105 is pivotally mounted on the plate. Therefore, the turntable 105 is adapted to occupy two positions along the transfer axis A3: a first position and a second position. In the first position, the center of the turntable 105 is positioned between the two pairs of studs 103 holding the right lens rim of the eyeglass frame 10; in the second position, the center of the turntable 105 is positioned between the two pairs of studs 103 holding the left lens rim of the eyeglass frame 10.

[0094] The turntable 105 has a rotation axis A4 defined as an axis perpendicular to the front surface of the turntable 105 and passing through its center. The turntable is adapted to pivot relative to a plate about said axis. The turntable 105 also has an arcuate elongated groove 106 through which the detector 110 can move. The detector 110 includes: a support rod 111 whose axis is perpendicular to the front surface plane of the turntable 105; and a detection finger 112 at its free end, whose axis is perpendicular to the support rod 111. The detection finger 112 is designed to slide or possibly roll along the bottom edge of the groove of each lens ring 11 of the eyeglass frame 10 to follow the bottom edge.

[0095] The shape reading device 100 includes an actuation device (not shown) adapted to: firstly slide a support rod 111 along a groove 106 to modify its radial position relative to the axis of rotation A4 of the turntable 105; secondly change the angular position of the turntable 105 about its axis of rotation A4; and thirdly position the probe finger 112 of the detector 110 at a higher or lower height relative to the front plane of the turntable 105.

[0096] In summary, the detector 110 has three degrees of freedom: a first degree of freedom R, which is constituted by the ability of the detector 110 to move radially relative to the axis of rotation A4 due to its freedom to move along the arc formed by the slot 106; a second degree of freedom θ, which is constituted by the ability of the detector 110 to pivot about the axis of rotation A4 by means of the rotation of the turntable 105 relative to the plate; and a third degree of freedom Z, which is constituted by the ability of the detector 110 to translate along an axis parallel to the axis of rotation A4 of the turntable 105.

[0097] Each point read by the end of the detector finger 112 of the detector 110 is located in the corresponding coordinate system R. j θ j Z j Chinese identifier.

[0098] The shape reading device 100 also includes an electronic and / or computer device 120, which is used first to control the actuation device of the shape reading device 100 and second to acquire and store the coordinates of the end of the probe finger 112 of the detector 110.

[0099] The electronic and / or computer device 120 is connected to a human-machine interface, which may be, for example, a touch screen 121.

[0100] During the first operation, the user uses, for example Figure 5 The reading device shown reads one lens ring 11 of the eyeglass frame 10 (the other lens ring is read in the same way and will not be described).

[0101] Initially, the eyeglass frame 10 is inserted between the studs 103 of the chuck 102 of the reading device 100, such that each lens ring 11 of the eyeglass frame is ready to be probed along a path that begins with inserting the detector 110 into an initial position along the left lens ring 11 of the frame, and then passes through the groove 16 of the lens ring 11 to cover the entire circumference of the lens ring 11. The initial position corresponds to a point between the two studs located at the bottom portion of the retaining lens ring.

[0102] In this initial position, the electronic and / or computer device 120 orients the tip θ of the detection finger 112 of the detector 110. j and height Z jIt is limited to being equal to zero.

[0103] After this, the actuation device pivots the turntable 105. As the turntable pivots, the actuation device applies a constant radial force to the detector 110, advancing the detector toward the slot 16, such that the detector finger 112 of the detector 110 slides along the bottom edge 17 of the slot 16 without lifting either the front side 16A or the rear side 16B of the slot 16.

[0104] As the turntable 105 rotates, the electronic and / or computer device 120 reads the three-dimensional coordinates R of multiple points (e.g., 360 points spaced angularly at one-degree intervals) along the bottom edge 17 of the slot 16. j θ j Z j Each point corresponds to the bottom edge 17 of the groove in section S. j The traces in the text basically correspond.

[0105] After the turntable 105 has completed one full revolution, the actuator stops its rotation. At this position, the detector 100 is positioned between two studs holding the bottom portion of the mirror ring.

[0106] The three-dimensional coordinates R of the 360 ​​detected points j TETA j Z j The outline C17 is considered to characterize the bottom edge 17 of the groove 16. Figure 10 (As shown).

[0107] During the second operation, the user uses the reading device 100 to view at least one section S of the lens rim 11 of the eyeglass frame 10. j Perform the reading.

[0108] Therefore, the first step is to determine the cross section S to be probed. j Orientation θ j The process used to determine this orientation will be explained below.

[0109] Then, the detector 110 is positioned in the groove 16 of the mirror ring 11, at the cross section S to be detected. j The upper edge 17 of the groove 16 is abutted against.

[0110] To achieve this, the detector 110 can be slid along the bottom edge 17 of the groove 16 again until the detector reaches the determined cross section S. j Orientation θ j .

[0111] In a variant, the detector 110 can leave the slot and directly reach the previously detected cross-section S belonging to the section to be detected. j point.

[0112] After this, the actuation device raises the detector 110 and then lowers it to abut against the front side 16A and rear side 16B of the slot 16.

[0113] As detector 110 moves, electronic and / or computer device 120 moves along the cross section S of slot 16. j Read the 3D coordinates R of multiple points (e.g., points spaced one millimeter apart). j θ j Z j Each point corresponds to slot 16 in plane P2. j Section S in j The traces are basically corresponding.

[0114] This operation can be performed by continuously sliding the detector along the sides 16A and 16B of the slot 16. In a variant, it can be performed by having the detector successively touch several points on these sides and removing the detector from the slot between each touch.

[0115] This operation can be performed on a single cross-section S of the groove 16. j Executed in or at several different sections S j Executed in China.

[0116] In probing each cross section S j Before that, the cross section S to be probed must be determined. j Orientation θ j .

[0117] Since probing a cross section is a lengthy operation, the goal is to read the minimum number of cross sections.

[0118] Therefore, the cross section S to be detected j Orientation θ j It is not determined randomly.

[0119] In a preferred embodiment, the cross section S to be detected j Orientation θ j Different frame models have different requirements. In other words, each orientation is determined based on the frame model.

[0120] Each orientation is determined by an optician or via electronic and / or computer device 120.

[0121] In the first embodiment, each cross section S to be detected j Orientation θ j The optician will determine this via touchscreen 121.

[0122] To this end, the electronic and / or computer device 120 displays the shape of the outline of the bottom edge 17 of the (previously detected) groove 16 on a touchscreen. The optician can then touch the area of ​​that outline on the screen to indicate the section S to be detected. j .

[0123] In the second embodiment, the optician can rotate the turntable 105 until a good orientation θ is achieved. j The detector 110 is manually positioned at the cross section S to be detected. j middle.

[0124] In these embodiments, the optician can select the section S based on the shape of the bevel 16. j For example, areas where interference might occur can be selected. In variations, the areas where the nose pads and temples are attached to the lens rims can be selected.

[0125] In the third embodiment, each orientation θ is calculated by electronic and / or computer device 120 based on the shape of the contour of the bottom edge 17 of the groove 16. j .

[0126] Therefore, such as Figure 7 As shown, the electronic and / or computer device 120 calculates the position of the outline center (referred to as the "box center") of the bottom edge 17 of the slot 16 and the position of the horizontal rectangle (referred to as the "box rectangle") that circumscribes the outline.

[0127] Regarding the center and rectangle of these boxes, the outline of the bottom edge 17 can be divided into four 90° angular sectors AS1, AS2, AS3, and AS4, namely the upper angular sector AS1, the bottom angular sector AS2, the nasal angular sector AS3, and the temporal angular sector AS4.

[0128] Then, the electronic and / or computer device 120 can detect the two cross sections S to be probed. j The orientation θ of the two sections to be probed is determined by locating them in the nasal horn sector AS3 and the temporal horn sector AS4, respectively. j .

[0129] For example, the first section can be located on the bisector of the nasal horn sector AS3, and the other section can be located on the bisector of the temporal horn sector AS4.

[0130] In fact, such as Figure 7 As shown, interference problems between the lens and the frame rim typically occur near these sections. In contrast, interference problems generally do not occur in the upper corner sector AS1 and the lower corner sector AS2.

[0131] In the variation, the two cross sections S can be determined in other ways. j Orientation θj For example, if the electronic and / or computer device 120 detects that the outline of the bottom edge 17 of the recess 16 is clearly rectangular, the section can be selected as belonging to the ray that passes through the upper corner of the rectangle from the center of the box. In practice, interference problems typically occur in the areas where the temples and nose pads are attached, and these areas are usually located near these corners.

[0132] like Figure 9 As shown, due to the shape of the detector 110 and the shape of the mirror ring 11, it is sometimes impossible to make the detector 110 slide along the entire side of both sides of the groove 16.

[0133] In this case, there are two solutions to obtain the entire cross section S of the groove 16. j The shape.

[0134] The first solution involves making the detector slide only on the portion PA1 of section Sj that can be detected by detector 110.

[0135] Then, since the cross section is known to be V-shaped, the shape of the remaining part of the cross section Sj can be calculated based on the shape of the detected part PA1 (which is formed by extending the detected line segment to form V).

[0136] The results of the first solution may not be as accurate as those of the second solution, but they are clearly usable.

[0137] like Figure 6 As shown, the second solution involves tilting the frame 10 within the reading device 100 in such a way that the entire cross-section S can be detected by the detector 110. j .

[0138] exist Figure 1 In the configuration shown, the two lens rims 11 of the frame are blocked by two pairs of studs 103, thereby horizontally securing the eyeglass frame 10 in the reading device 100. In this novel configuration (used when the outline of the bottom edge 17 of the groove 16 has been detected), the optician tilts the frame so that only one lens rim 11 is blocked by the stud 103. In this position, the orientation of the lens rim 11 allows the entire cross-section S to be detected. j .

[0139] To accurately determine the 3D shape of the groove 16, a possible solution is to probe a large number of cross-sections S. j However, as explained above, this operation may take too long to execute.

[0140] Therefore, the solution for accurately determining this 3D shape here includes determining the shape based on the probed cross section S. j The shape of the undetected section is calculated from the shape of the cross section.

[0141] In the first embodiment, since only one cross-section is known, it can be assumed that all cross-sections of the groove 16 along the contour C17 of the bottom edge 17 of the groove 16 are identical. Therefore, if only one cross-section S of the inclined surface 16 is probed... j Then it is assumed that the shape of each cross section of the groove 16 is the same as the shape of the probe cross section.

[0142] However, since the actual cross-sectional shape of the groove 16 is not the same, the second embodiment below is preferred.

[0143] In this second embodiment, a limited number of cross-sections are probed. This number is preferably between two and six. For example, four cross-sections located on the bisectors of the four corner sectors AS1-AS4 can be probed.

[0144] Then, the entire 3D shape of the groove 16 is calculated based on the shape of these probed cross-sections Sj, for example, by interpolation. In a preferred embodiment, the interpolation takes into account the shape of the profile of the bottom edge 17 of the groove 16.

[0145] This step in the instruction manual explains how to perform the interpolation.

[0146] exist Figure 2 In the embodiment shown, the groove is V-shaped, such that at a specific cross-section S j Three points are needed to limit V:

[0147] -The first point A located on the bottom edge 17 j ,

[0148] - The second point B is located at the intersection between the rear edge 19 and the rear side surface 16B of the groove 16. j ,as well as

[0149] - The third point C is located at the intersection between the front edge 18 and the front side surface 16A of the groove 16. j .

[0150] Note that point A j The coordinates are known across the entire frame outline, while point B... j Coordinates and point C j The coordinates are known only at the section being read.

[0151] Undetected section S located between the two detected sections S1 and S2 j Interpolation can be performed as follows.

[0152] To estimate point B j and point C j At section S j The coordinates in the diagram can be obtained using a known point A. jThe coordinates of points B1 and C1 in section S1, and the coordinates of points B2 and C2 in section S2.

[0153] Point B j Located on the interval [B1', B2'], where:

[0154] -B1' is its relative to point A j The position of point B1 is equal to the position of point A1, and

[0155] -B2' is its relative to point A j The position of point B2 is equal to the position of point A2.

[0156] Point B j The position on the interval [B1', B2'] depends on the cross section S. j angular position θ on the lens ring profile j Comparison of the angular positions θ1 and θ2 of sections S1 and S2.

[0157] More specifically, point B1 and point B j The distance between them should be equal to the distance between points B1 and B2 multiplied by the number of terms α, where:

[0158] A = |θ1 - θ j | / |θ1-θ2|.

[0159] Point C can be determined in the same way. j The coordinates.

[0160] In this step, the three-dimensional coordinates R of 360 points probed along the bottom edge 17 of the groove 16 are determined. j TETA j Z j It is known.

[0161] The three-dimensional coordinates R of several points characterizing the shape of the side surface of the groove 16 j TETA j Z j This is also known.

[0162] In other words, all the data required to machine the edge of the lens 20 to be joined in the lens rim under consideration was obtained.

[0163] Therefore, these data can be processed to determine the grinding parameters that the electronic and / or computer device 120 can transmit to the forming tool.

[0164] According to the invention, these edge-grinding parameters are calculated such that once the lens is edge-grinded, it has a bevel along its entire contour and at least one specific cross-section S' iThe shape in depends on the cross section S of the probe. j The shape of at least one of them.

[0165] In fact, the grinding parameters are calculated to automatically determine the most appropriate geometry for the bevel.

[0166] Several embodiments can achieve this objective.

[0167] exist Figure 8 In the first embodiment shown, the grinding parameters are determined such that once machining is performed, the lens bevel 26 is tilted and its angle varies to maintain alignment with the groove 16 in each cross-section S. j The skew angle C in j equal.

[0168] More specifically, in this embodiment, each section S' of the inclined plane 26 i It exhibits its own tilt angle C' i Inclination angle C' i The angle bisector F' corresponding to the inclined plane 26 i The angle between the axis perpendicular to the average axis A2 in the average plane P'1 of lens 20.

[0169] exist Figure 11 In the second embodiment shown, the edge grinding parameters are determined such that, once machining is performed, the bevel is not tilted, but the front edge 28 and the rear edge 29 are positioned at a radial distance different from the top edge 27 of the bevel (this radial distance is measured from the average axis A2 of the lens).

[0170] At section S' i The difference H' between these distances i It can be equal to the difference between the following two:

[0171] -At the corresponding section S j The radial distance between the central axis A1 and the end of the front side 16A of the groove 16, and

[0172] - at the corresponding section S j The radial distance between the central axis A1 and the end of the rear side 16B of the groove 16.

[0173] However, in the preferred embodiment, the difference H' i Equal to the angle bisector F' of the inclined plane 26 i The difference between two measured distances.

[0174] In other embodiments, more generally, the grinding parameters cause the bevel 26 to be present in each section S' i The shape depends on at least one of the following data:

[0175] -At the corresponding section S j The angle Dj between the front side 16A and the rear side 16B of the central groove 16

[0176] -Groove 16 at section S j Depth in the middle,

[0177] - The position of the bevel 16 in the thickness of the lens rim (expressed as a percentage, 50% corresponds to the center position of the groove in the thickness of the lens rim).

[0178] - Deflection angle C j .

[0179] Once determined, the edging parameters are sent to the edging machine, and the lens 20 is machined to form a bevel 26. Control setpoints for machining the lens are derived based on all received edging parameters.

[0180] This step includes machining the edge surface 23 of the ophthalmic lens 20 to reduce it to the shape of the corresponding lens rim 11 of the eyeglass frame 10, in such a way that once the lens 20 is engaged in its lens rim 11, the front edge 28 and the rear edge 29 of the lens extend around the entire contour of the lens rim at substantially constant distances from the front edge 18 and the rear edge 19 of the left lens rim 11, respectively.

[0181] Therefore, once the machining is completed, the lens is ready to be installed in the corresponding lens ring 11 of the frame 10.

[0182] As explained above, probing each cross-section of the groove is time-consuming. Therefore, a solution to reduce the time required to obtain the shape of these cross-sections is to store the measurement data or grinding parameters in a database register.

[0183] The register may, for example, have a first field for storing an identifier for the frame model (or frame model category). This identifier may be formed from the name of the model. The register may also have other fields for storing measurement data and / or edge grinding parameters.

[0184] This register allows opticians to search the database to see if the frame model is known in the database when they receive the frames.

[0185] If no result is found, the process described above will be executed.

[0186] Conversely, if the corresponding registered information is found, the data stored in that register is read and used to machine the lens. In this case, only the bottom edge 17 of the bevel 16 is read by the reading device 100, without probing the cross-section of the bevel.

[0187] The present invention is by no means limited to the embodiments described and shown.

[0188] For example, in the above embodiment, the reading device 100 successively reads the shape of the longitudinal profile of the bottom edge 17 of the groove and the detected cross section S. j The shape. However, in the variant, only the reading of the bottom edge 17 of the groove can be read first. Subsequently, the shape of the probed cross-section can be read. For example, they can be read during the first step of lens machining, in which case information related to the cross-section may not be needed. To save time, the cross-section can also be probed during the centering process.

[0189] In the above embodiment, the entire cross-section is read (by controlling the detector to slide on both the front side 16A and the rear side 16B of the slot 16). In a variant, only the rear portion of the cross-section of the slot 16 can be probed. In practice, interference problems between the frame and the lens rarely occur on the front side of the bevel. This problem typically occurs on the rear side (see...). Figure 7 Therefore, in this variant, to reduce the time required to probe the cross sections, only the rear portion of these cross sections is probed. For example, this rear portion corresponds to the trace on the rear side 16B of the groove 16.

[0190] In this variation, only one point on the rear side of the groove can be probed. Then, the shape of the trace on the rear side 16B is assumed to be a line segment passing through that point and the bottom edge 17 of the groove 16.

[0191] In this variant, to detect a point on the rear side of the slot across a large number of cross sections, the detector can be slid along (against) the rear side by rotating the turntable and keeping the detector at a constant distance from the bottom edge 17 of the slot at height Z.

[0192] like Figure 10 As shown, this operation can be performed on the plane (R) j θ j The shape of the outline C17 of the bottom edge 17 of the groove and the shape of the outline C18 passing through the point probed on the rear side 16B of the groove 16 are outlined in the figure.

Claims

1. A method for determining the shape of a groove (16) in an eyeglass frame rim (11), the rim (11) comprising a front and a back, with a temple (14) attached to the back side, the method comprising: - The step of obtaining the shape of the longitudinal contour of the groove (16), and - By moving the moving detector (110) in the slot (16) to at least one section (S) of the slot (16). j The detection steps involve detecting at least a portion of the object. The method is characterized in that, prior to the detection step, it includes calculating or indicating the cross section (S) to be detected along the longitudinal profile. j Orientation (θ) j The calculation or steps are indicated, and During the detection step, only the cross section (S) is examined. j The rear portion of the cross section (S) is probed. j The rest of the lens is closer to the back of the lens ring.

2. The method according to claim 1, wherein, The operator manually points out the location of the cross section through the human-machine interface (121).

3. The method according to claim 1, wherein, The cross section (S) is automatically calculated based on the shape of the longitudinal profile. j The position of ).

4. The method according to claim 1, wherein, In calculating or indicating the cross section (S) j Orientation (θ) j After the calculation or indication step, the detector moves automatically without sliding along the slot (16) directly to the orientation (θ). j ).

5. The method according to claim 1, wherein, In calculating or indicating the cross section (S) j Orientation (θ) j Following the calculation or indication step, the detector moves automatically, sliding along the slot (16) to reach the orientation (θ). j ).

6. The method according to claim 1, wherein, The longitudinal profile includes four angular sectors (AS1, AS2, AS3, AS4) of equal extent, comprising an upper angular sector, a lower angular sector, a nasal angular sector, and a temporal angular sector. The cross-section (S j It is located in the nasal lateral angle sector or the temporal lateral angle sector.

7. The method according to claim 1, wherein: - During the calculation or indication step, at least two cross-sections (S) of the groove are calculated or indicated. j The position of ) and - During the detection step, the at least two cross sections (S) are controlled by moving the moving detector (110) in the slot (16) in two different planes (P2). j ) to conduct detection.

8. The method according to claim 7, wherein, According to the detected cross section (S) j The shape of at least one undetected section of the groove (16) is calculated by the shape of the groove (16).

9. The method according to claim 8, wherein, According to the detected cross section (S) j The shape of the slot (16) is calculated by interpolation to determine the entire 3D shape of the slot (16).

10. The method according to claim 1, wherein, If the detector (110) can only detect the cross section (S) j If a portion (PA1) is probed, the cross section (S) is calculated based on the shape of the probed portion (PA1). j The shape of the rest of the part.

11. The method of claim 1, wherein the method comprises adjusting the shape of the longitudinal profile and / or the cross-section (S) to match the shape of the longitudinal profile and / or the cross-section (S). j The step of storing shape-related data in a register, where each entry is associated with a frame model or model category.

12. The method according to claim 1, wherein, The step of obtaining the shape of the longitudinal profile of the groove (16) is performed by a reading device (100) during the detection operation, and wherein the step of detecting at least a portion of the cross section is performed during an operation different from the detection operation.

13. A method for machining a lens (20) to be mounted in an eyeglass frame rim (11), the method comprising: - A first operation, the first operation comprising performing the method according to claim 1 by means of a reading device (100). - A second operation, the second operation comprising determining the shape of the longitudinal profile and the cross section of each probe (S) j The shape of the edge determines the grinding parameters, and - A third operation, the third operation comprising edging the lens (20) by means of an edging machine according to the edging parameters, so as to form a bevel (26) along at least a portion of the contour of the lens (20). The grinding parameters cause at least one specific cross section (S') of the bevel (26) to be... i The shape of the groove depends on the cross-section (S) of the probe. j ).

14. The method according to claim 13, wherein, The grinding parameters make the specific cross section (S') of the bevel (26) i The shape of () depends on one of the following data: - In the cross section (S) of the probe j The angle (D) between the front side (16A) and the rear side (16B) of the groove (16) described above. j ), - The groove (16) is in the probe section (S) j Depth on ) - The inclined plane (26) is in the probe section (S) j The longitudinal position of the lens in the thickness of the frame. - The groove (16) is in the probe section (S) j The skew angle (C) in ) j ).

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