The invention relates to the manufacturing of a lens such as an ophthalmic lens, and a system for the manufacturing of such an ophthalmic lens.
It is well known that lenses, and in particular spectacle lenses, comprise an ophthalmic substrate having geometrical features adapted to the wearer.
Some coatings can be added on the ophthalmic substrate to obtain a finished ophthalmic lens. The coatings are for instance an anti-abrasive coating to increase the abrasion resistance of the lens, and/or an anti-reflective coating to decrease the reflection of light and/or an anti-soiling coating applied over the anti-reflective coating.
One known method to manufacture an ophthalmic substrate is described in European patent application EP 2 093 018, in which a single blocking piece is provided for surfacing and edging the ophthalmic substrate.
The blocking piece is made from a plastic material moulded in a single piece and is configured to receive an optical substrate, also named blank.
The blocking piece has a reception zone of the blank which is delimited by a peripheral outline and which has a diameter similar to the diameter of the blank.
The blank is mounted and fixed to the blocking piece, a first face of the blank facing a mounting face of the blocking piece.
The system formed by the blank and the blocking piece is then mounted on a surfacing machine for the surfacing of a second face of the blank, the second face being opposite to the first face.
Next, a step of surfacing of the second face of the blank is carried out.
The system formed by the blocking piece and the blank whose second face is machined is then transferred to an edging machine (for instance a grinder) for the edging of a peripheral edge of the blank, which edge links the first and second faces of the blank.
Next, a step of edging of the edge of the blank is carried out. During, the step of edging, the outline of the single blocking piece is further machined.
A substantial portion of the single blocking piece is removed because the step of edging generally machines the blank from a maximum first diameter, for instance equal to around 70 mm, to a maximum second diameter smaller than the first diameter, for instance 30 mm. The second face and the outline of the blank are thus machined in order to form the ophthalmic lens (or at least the ophthalmic substrate) which is cut and has a shape similar to a shape of the spectacle frame on which the ophthalmic lens is configured to be mounted.
The single blocking piece made from plastic material is thus here a disposable blocking piece.
The invention is directed to a method of manufacturing an ophthalmic lens, comprising a step of surfacing and a step of edging, the method being simple, convenient and economical to carry out.
The invention accordingly provides a method of manufacturing an ophthalmic lens having a first face, a second face opposite to said first face and a peripheral outline linking said first and second faces, the method comprising the following steps:
wherein said machining support unit comprises a surfacing member and an edging member separable from said surfacing member, said surfacing member having a cavity defining an internal space in which said edging member is located during said step of surfacing, said surfacing member and edging member being configured so that said substrate is mounted and blocked on said machining support unit in a first predetermined position for the surfacing of said upper face and for the edging of said peripheral edge, and, between said steps of surfacing and edging, the method further comprises the step of withdrawing said surfacing member from said machining support unit by retaining said substrate on said edging member.
Thanks to the method according to the invention, the substrate is only once positioned, is blocked for the step of surfacing and is not unblocked for the step of edging. This is the removal of the surfacing member which allows the step of edging to be carried out.
The positioning of the substrate in the first predetermined position on the machining support unit, in other words relative to the surfacing member and relative to the edging member, is even retained after the step of surfacing so that the step of edging can be directly carried out. The positioning reference is thus not lost between surfacing and edging, by virtue of which the method according to the invention allows to improve the quality of the ophthalmic lens.
Contrarily to the disposable blocking piece of the state of the art described above, the machining support unit used in the method according to the invention is reusable.
The method of manufacturing according to the invention is thus precise, simple, convenient and economical to carry out.
According to features preferred as being very simple, convenient and economical for embodying the method according to the invention:
The invention further provides a system for the manufacturing of an ophthalmic lens having a first face, a second face opposite to said first face and a peripheral outline linking said first and second faces, said system comprising:
wherein said machining support unit comprises a surfacing member and an edging member separable from said surfacing member, said surfacing member has a cavity defining an internal space in which said edging member is configured to be located during said surfacing of said upper face, said surfacing member and edging member are configured so that said substrate is mounted and blocked on said machining support unit in a first predetermined position for said surfacing of said upper face and for said edging of said peripheral edge, and said surfacing member and edging member are further configured so that said surfacing member is able to be withdrawn from said machining support unit by retaining said substrate on said edging member for said edging of said peripheral edge.
Thanks to the removability of the surfacing member from the machining support unit, the system according to the invention is thus configured so that the substrate is only once positioned, is blocked for a step of surfacing and is not unblocked for a step of edging. Only the surfacing member has to be removed from the machining support unit to directly carry out the step of edging.
The positioning of the substrate in the first predetermined position on the machining support unit, in other words relative to the surfacing member and relative to the edging member, is retained even after the removal of the surfacing member from the machining support unit. The positioning reference is thus not lost between surfacing and edging, by virtue of which the method according to the invention allows to improve the quality of the ophthalmic lens.
Contrarily to the disposable blocking piece of the state of the art described above, the machining support unit of the system according to the invention is reusable.
The system according to the invention is thus precise, simple, convenient and economic.
According to features preferred as being very simple, convenient and economical for embodying the system according to the invention:
The description of the invention now continues with a detailed description of a preferred embodiment given hereinafter by way of non-limiting example and with reference to the appended drawings. In these drawings:
This machine 1 is configured for machining by turning (surfacing) an upper face 12 of an ophthalmic substrate 10 in order to form a second face of an ophthalmic lens, including a surface of a progressive lens further having toric and/or prismatic components.
To this end, the machine 1 comprises a surfacing tool 8 and a control unit 2 comprising a microprocessor 3 having a memory 4, in particular a non-volatile memory, allowing it to load and store software, in other words a computer program, which when it is executed in the microprocessor 3, allows the implementation of a manufacturing method according to the invention.
This non-volatile memory 4 is for example of the ROM (“read only memory”) type.
The control unit 2 further comprises a memory 5, in particular a volatile memory, allowing data to be stored during the execution of the software and the implementation of the method.
This volatile memory 5 is for example of the RAM or EEPROM type (respectively “random access memory” and “electrically erasable programmable read only memory”).
The machine 1 further comprises a glazed aperture 6 suitable for allowing the upper face 12 of the substrate 10 on which the machine 1 is operating to be viewed.
This glazed aperture 6 makes it possible, during the implementation of the method, for a user of the machine 1 to monitor the satisfactory progress of the method by viewing the substrate 10 in the machine 1.
The machine 1 can also be configured for polishing the upper face 12 and for edging a peripheral edge 13 of the ophthalmic substrate 10 in order to form the ophthalmic lens.
To this end, the surfacing tool 8 has to be replaced by a polishing tool and/or an edging tool.
In variant, the polishing machine and/or the edging machine are (is) distinct from the surfacing machine and the polishing machine and/or the edging machine are (is) substantially similar to the surfacing machine, except that there is no surfacing tool but a polishing tool and/or an edging tool.
The system 60 comprises the ophthalmic substrate 10, a fastening (or fixation) member 20 and a machining support unit 65.
The ophthalmic substrate 10 comprises the upper face 12, a lower face 11 opposite to the upper face 12 and the peripheral edge 13 linking the lower and upper faces 11 and 12.
The ophthalmic substrate 10 has here a diameter equal to about 70 mm.
The lower face 11 is configured to form a first face, also named front face, of the ophthalmic lens.
The upper face 12 is configured to form (after surfacing) a second face, also named rear face, of the ophthalmic lens.
The second face is opposite to the first face.
The peripheral edge 13 is configured to form (after edging) a peripheral outline of the ophthalmic lens, the peripheral outline linking the first and second faces.
Here, the lower face 11 of the substrate 10 is convex. The lower face 11 comprises optical properties (for instance simple for a single vision lens or complex for a progressive lens), and already forms the front face of the ophthalmic lens. That is why the substrate 10 is here named ophthalmic substrate. Such ophthalmic substrate 10 can also be named semi-finished blank.
The fastening member is formed by an adhesive film 20 which has a first adhesive face 21 and a second adhesive face 22 opposite to the first adhesive face 21.
The first adhesive face 21 is configured to be fixed on the machining support unit 65 and the second adhesive face 22 is configured to be fixed on the lower face 11 of the ophthalmic substrate 10. The adhesive film 20 is deformable.
The machining support unit 65 is configured to receive the ophthalmic substrate 10 for surfacing the upper face 12 and further for edging the peripheral edge 13.
The machining support unit 65 comprises a surfacing member 40 and an edging member 30.
The edging member 30 is made from a plastic material moulded in a single piece.
The edging member is formed by a pin 30 which comprises a circular flange having a lower face 31, an upper face 32 opposite to the lower face 31 and a peripheral outline 33 linking the lower and upper faces 31 and 32.
The upper face 32 is configured to partially form a mounting face of the machining support unit 65.
This upper face 32 has a general curved-shape which matches at least partially with the shape of the lower face 11 of the ophthalmic substrate 10.
The pin 30 further comprises a block 34 which protrudes from the lower face 31.
The block 34 comprises a lateral wall which extends from the lower face 31.
The block 34 further comprises a beveled portion 38 at least partially circular and linked to the cylindrical lateral wall 35.
The block 34 further comprises a notch 37 diametrically formed in the cylindrical lateral wall 35.
The block 34 further comprises a bearing face 36 at a free end of the block 34 (at the opposite of the lower face 31).
The pin 30 is configured to be accommodated in the surfacing member 40.
The pin 30 is further configured to be separable from this surfacing member 40.
The surfacing member is formed by a ring 40 made from a plastic material moulded in a single piece.
The ring 40 comprises a body 41 having a generally cylindrical shape.
The body 41 comprises a cylindrical lateral wall 42 which defines an internal lateral face 52 and a free edge 44.
The body 41 further comprises a tapered wall 43 linked to the cylindrical lateral wall 42 at the opposite of the free edge 44.
The body 41 further comprises a bottom wall 45 linked to the tapered wall 43 at the opposite of the cylindrical lateral wall 42.
The tapered wall 43 and the bottom wall 45 define an internal bottom face 53 of the ring 40.
The internal lateral face 52 and the internal bottom face 53 (the latter being tapered) define an internal space of a cavity 51 of the ring 40.
The internal lateral face 52 and the internal bottom face 53 further partially form the mounting face of the machining support unit 65, together with the upper face 32 of the pin 30.
The internal bottom face 53 is configured to have a shape which partially matches with the shape of the lower face 11 of the ophthalmic substrate 10.
It should further be noted that the internal lateral face 52 is configured to have a shape which partially matches with the shape of the peripheral edge 13 of the ophthalmic substrate 10.
The body 41 further comprises a base 46 configured to be mounted on a surfacing machine and on an edging machine as shown in
The base 46 comprises a lateral wall 47 linked to the bottom wall 45, a tapered wall 46 linked to the lateral wall 47 and a bearing face 49 at a free end of the base 46, the free end being opposite to the bottom wall 45.
The base 46 further comprises a slot 50 diametrically formed on the tapered wall 48.
The slot 50 forms two notches in the tapered wall 48 and a centrally opening between these two notches.
The body 41 further comprises a recess formed in the internal bottom face 53, the recess forming a housing 62 configured to receive the pin 30.
The housing 62 comprises a wall 55 linked to the internal bottom face 53, a bottom 56 linked to the wall 55 at the opposite of the internal bottom face 53 and two grooves 57 formed in the bottom 56.
Each groove 57 has a bottom 59 and the two grooves 57 are separated from each other by a rib 58.
It should be noted that the housing 62 belongs to the cavity 51 which defines an internal space in which the pin 30 is configured to be located.
We will now describe in detail the system 60 having the ophthalmic substrate 10, the adhesive film 20 and the machining support unit 65 (in other words the pin 30 together with the ring 40) which are assembled.
The pin 30 is accommodated in the housing 62 of the ring 40.
The lower face 31 of the pin 30 faces the bottom 56.
The block 34 is partially introduced in the grooves 57, the bearing face 36 of the block 34 coming into abutment against the bottom 59 of the grooves 57, and the rib 58 is received in the notch 37.
The pin 30 is thus mounted and positioned in a predetermined position in the ring 40.
As mentioned above, the mounting face of the machining support unit 60 is here formed by the internal bottom face 53 of the ring 40 and by the upper face 32 of the pin 30.
The adhesive film 20 is fixed by its first adhesive face 21 on the upper face 32 of the pin 30.
The adhesive film 20 has here a diameter which is slightly smaller than the diameter of the pin 30.
The ophthalmic substrate 10 is mounted on the mounting face of the machining support unit 65. The lower face 11 of the ophthalmic substrate 10 faces the internal bottom face 53 of the ring 40 and further faces the second adhesive face 22 of the adhesive film 20 together with the upper face 32 of the pin 30.
The adhesive film 20 is thus partially located on the mounting face and is sandwiched between the machining support unit 65 and the lower face 11 of the ophthalmic substrate 10.
The peripheral edge 13 of the ophthalmic substrate 10 partially faces the internal lateral face 52 of the ring 40.
The lower face 11 of the ophthalmic substrate 10 comes into abutment against the second adhesive face 22 of the adhesive film 20.
Thus, the ophthalmic substrate 10 is mounted and fixed to the machining support unit 65, thanks to the internal lateral face 52 and the internal bottom face 53 (for the positioning); and thanks to the upper face 32 of the pin 30 together with the second adhesive face 22 of the adhesive film 20 (for the fixing).
The internal lateral face 52, the internal bottom face 53 and the housing 62 of the ring 40 together with the pin 30 are configured so that the ophthalmic substrate 10 is mounted and blocked (fixed) on the machining support unit 65 in a first predetermined position for the surfacing of the upper face 12 and for the edging of the peripheral edge 13.
The first predetermined position is defined by an alignment of a first reference point of the ophthalmic substrate 10 with a first geometrical center of the ring 40 and further by an alignment of a second reference point of the ophthalmic substrate 10 with a second geometrical center of the pin 30.
The first reference point is in the upper face 12 of the ophthalmic substrate 10 and corresponds to a rotation center of this ophthalmic substrate 10 relative to a first machining referential of the surfacing machine; and the second reference point of the ophthalmic substrate 10 corresponds to an optical center and/or a boxing center of this ophthalmic substrate 10 relative to a geometrical shape of the ophthalmic lens to obtain and relative to a second machining referential of the edging machine. The first machining referential and the second machining referential can be identical or distinct.
The machining support unit 65 is configured so that the ring 40 is able to be removed from the machining support unit 65 by retaining the ophthalmic substrate 10, the adhesive film 20 and the pin 30, after the surfacing of the upper face 12, and for the edging of the peripheral edge 13.
We will now describe the method for manufacturing the ophthalmic lens in reference to
The method comprises a step 100 of providing a semi-finished blank (SF1) here formed by the ophthalmic substrate 10.
The method further comprises a step 110 of providing a machining support unit 65 for surfacing and edging the ophthalmic substrate 10.
The machining support unit 65 comprises a surfacing ring 40 and an edging pin 30.
The method further comprises a step 120 of mounting the ophthalmic substrate 10 on the machining support unit 65 in the first predetermined position and blocking (or fixing) the ophthalmic substrate 10 on this machining support unit 65, here by the intermediary of the adhesive film 20.
In this first predetermined position, the lower face 11 of the ophthalmic substrate 10 faces the mounting face (the upper face 32, the internal lateral face 52 and the internal bottom face 53) of the machining support unit 65.
The method further comprises a step 130 of surfacing the upper face 12 of the ophthalmic substrate 10 in order to obtain a surfaced ophthalmic substrate 10.
The method may further comprise a step 135 of polishing the upper face 12 surfaced of the ophthalmic substrate 10 in order to obtain a polished surfaced ophthalmic substrate 10.
The method further comprises a step 140 of withdrawing the surfacing ring 40 from the machining support unit 65 by retaining the ophthalmic substrate 10 together with the pin 30 (the adhesive film 20 being sandwiched between the ophthalmic substrate 10 and the pin 30), in the first predetermined position of the ophthalmic substrate 10 relative to the pin 30.
The method further comprises a step 150 of edging the peripheral edge 13 of the ophthalmic substrate 10 in order to obtain the ophthalmic lens.
The method may further comprise a step of coating the upper face 12 of the ophthalmic substrate 10, for instance with an anti-reflective coating or a photochromic coating or a polarizing coating, to form for instance a top-coat or a hard coat, between the steps of surfacing and edging or after these steps.
The method may further comprise a step of coating the lower face 11 of the ophthalmic substrate 10, for instance with an anti-reflective coating or a photochromic coating or a polarizing coating, to form for instance a top-coat or a hard coat, after the steps of surfacing and edging.
The method further comprises a step 160 of unblocking the ophthalmic lens (or the ophthalmic substrate 10 surfaced and edged) from the pin 30 and thus from the adhesive film 20.
The machining support unit 65 is thus reusable for another method of manufacturing of an ophthalmic lens.
This ophthalmic lens comprises the first face formed from the lower face 11, the second face formed from the surfaced upper face 12 and the peripheral outline formed from the edged peripheral edge 13.
In variants that are not illustrated:
It should be more generally noted that the invention is not limited to the described and represented examples.
Filing Document | Filing Date | Country | Kind |
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PCT/IB2013/000438 | 1/9/2013 | WO | 00 |