Method of centering an ophthalmic lens on a rimless frame

1. A method of centering a target ophthalmic lens ( 11 , 12 ) of target eyeglasses ( 10 ) on a target frame ( 13 ) of the rimless type presenting a final outline ( 21 ) of known shape, with a bridge ( 14 ) and arms ( 15 , 16 ) fastened to the target lens at anchor points ( 17 , 18 , 19 , 20 ) defined relative to the final outline ( 21 ), the method comprising the steps of:

a) fitting the wearer with presentation eyeglasses ( 30 ) comprising a presentation frame ( 33 ) identical to said target frame ( 13 ) and at least one presentation lens ( 31 , 32 ) associated with the same eye as said target lens;

b) pointing out manually, or identifying automatically, on the presentation lens ( 31 , 32 ) the pupillary point (Pu 2 ) with which the pupil ( 50 ) of the corresponding eye ( 51 ) of the wearer is in register;

c) measuring the pupillary height of the pupillary point (Pu 2 ) of the presentation lens ( 31 , 32 );

d) measuring the pupillary distance or half-distance (Eg, Ed) of the wearer;

e) identifying the optical frame of reference of the target lens ( 11 , 12 ) and in particular the centering point (Pc 1 ) of the target lens ( 11 , 12 ) that is to come into register with the pupil ( 50 ) of the wearer when the wearer is wearing the target eyeglasses ( 10 );

f) transferring the pupillary height and the pupillary distance or half-distance onto the target lens ( 11 , 12 ) from said centering point (Pc 1 ) of the target lens ( 11 , 12 ); and

g) deducing therefrom the centering position of the target lens ( 11 , 12 ) relative to the target frame ( 13 ), or vice versa;

characterized in that, for the presentation lens ( 31 , 32 ) presenting an outline ( 41 ) of shape and/or position relative to the presentation frame differing from the shape and/or position intended for the final outline ( 21 ) of the target lens ( 11 , 12 ) after edging and mounting on the target frame, the following steps are performed:

directly or indirectly measuring in step c), the height (h) of the pupillary point (Pu 2 ) of the presentation lens ( 31 , 32 ) in a frame of reference based on the presentation frame ( 33 ) and independent of the shape of the outline ( 41 ) of the presentation lens ( 31 , 32 ); and

deducing, in step g), the centering position of the target lens ( 11 , 12 ) relative to the target frame ( 13 ), or vice versa, so that the centering point (Pc 1 ), in a frame of reference based on the target frame ( 13 ) corresponding to the frame of reference of the presentation frame ( 33 ), is situated at the same height (h) as the pupillary point (Pu 2 ) in the frame of reference of the presentation frame ( 33 ).

2. A method according to claim 1 , comprising the steps of:

directly or indirectly measuring, in step c), the height difference (h) between the pupillary point (Pu 2 ) of the presentation lens ( 31 , 32 ) and a presentation remarkable point (Pr 2 ) associated with the presentation frame ( 33 ) and physically identifiable on said frame; and

deducing, in step g), the centering position of the target lens ( 11 , 12 ) relative to the target frame ( 13 ), or vice versa, so that a target remarkable point (Pr 1 ) associated with the target frame ( 13 ), corresponding to the presentation remarkable point (Pr 2 ) of the presentation frame, presents the same height difference (h) relative to the centering point (Pc 1 ) as the height difference of the presentation remarkable point (Pr 2 ) relative to the pupillary point (Pu 2 ).

3. A method according to claim 2 , in which the presentation remarkable point (Pr 2 ) of the presentation frame ( 33 ) is an anchor point of said frame on the presentation lens ( 31 , 32 ).

4. A method according to claim 3 , in which the presentation remarkable point (Pr 2 ) is an anchor point of the bridge ( 34 ) of the presentation frame ( 33 ) on the presentation lens ( 31 , 32 ) concerned.

5. A method according to claim 3 , in which the presentation remarkable point (Pr 2 ) is an anchor point for an arm ( 35 , 36 ) of the presentation frame ( 33 ) on the presentation lens ( 31 , 32 ) concerned.

6. A method according to claim 2 , in which, in step c), the height difference (h) between the pupillary point (Pu 2 ) of the presentation lens ( 31 , 32 ) and the presentation remarkable point (Pr 2 ) of the presentation lens ( 33 ) is measured directly.

7. A method according to claim 2 , including the following steps:

numerically acquiring the shape of the outline of the presentation lens ( 31 , 32 ) and the position of said outline relative to the presentation frame, by outline reading and/or feeling and/or image recognition, or on the basis of an electronic file representative of its shape and position relative to the presentation frame;

measuring, in step c), the height difference (Hb 2 ; Hsp 2 ) between the pupillary point (Pu 2 ) of the presentation lens ( 31 , 32 ) and a presentation reference point (Pref 2 ) of the outline ( 41 ) of the presentation lens ( 31 , 32 );

performing calculation, taking account of the known shape of the outline ( 41 ) of the presentation lens ( 31 , 32 ) and of the known position of said outline ( 41 ) relative to the presentation frame ( 33 ), to deduce the height (H 2 ; H′ 2 ) of said presentation reference point (Pref 2 ) in the frame of reference associated with the presentation frame ( 33 ); and

deducing therefrom the height (h) of the pupillary point (Pu 2 ) of the presentation lens ( 31 , 32 ) in the frame of reference of the presentation frame ( 33 ).

8. A method according to claim 7 , including, in step c), performing calculation, taking account of the known state of the outline of the presentation lens ( 31 , 32 ) to determine the height difference between the presentation reference point (Pref 2 ) and said presentation remarkable point (Pr 2 ), and deducing therefrom the height difference (h) between the pupillary point (Pu 2 ) of the presentation lens ( 31 , 32 ) and said presentation remarkable point (Pr 2 ).

9. A method according to claim 7 , in which the presentation reference point (Pref 2 ) associated with the presentation lens ( 31 , 32 ) is the lowest point of the outline ( 41 ) of the presentation lens ( 31 , 32 ).

10. A method according to claim 7 , in which the presentation reference point (Pref 2 ) associated with the presentation lens ( 31 , 32 ) is the point of the outline of the presentation lens ( 31 , 32 ) that is situated vertically below the pupillary point (Pu 2 ).

11. A method according to claim 1 , in which the final outline ( 21 ) of the target lens ( 11 , 21 ) is selected from a database corresponding to the selected target frame ( 13 ).

12. A method according to claim 1 , in which the final outline ( 21 ) of the target lens ( 11 , 12 ) is selected by deforming the outline ( 41 ) of the presentation lenses ( 31 , 32 ).

13. A device for implementing the method according to claim 7 , the device comprising measurement means suitable for identifying the optical frame of reference of the target lens ( 11 , 12 ), input or acquisition means for inputting or acquiring the shape of the outline ( 21 ) of the target lens ( 11 , 12 ), and an electronic and/or computer system designed to perform the transfer and the deduction of steps f) and g) from the frame of reference of the target lens ( 11 , 12 ) identified in step e) by the measurement means and from the shape of the outline ( 21 ) of the target lens ( 11 , 12 ) acquired with the help of said input or acquisition means.

14. A device according to claim 13 , in which the electronic and/or computer system is designed to execute calculation of the height (H 2 ; H′ 2 ) of the presentation reference point (Pref 2 ) in the frame of reference associated with the presentation frame ( 33 ), and to deduce from said calculation the height (h) of the pupillary point (Pu 2 ) in the frame of reference associated with the presentation frame ( 33 ).

15. A device for implementing the method according to claim 1 , the device comprising measurement means suitable for identifying the optical frame of reference of the target lens ( 11 , 12 ), input or acquisition means for inputting or acquiring the shape of the outline ( 21 ) of the target lens ( 11 , 12 ), and an electronic and/or computer system designed to perform the transfer and the deduction of steps f) and g) from the frame of reference of the target lens ( 11 , 12 ) identified in step e) by the measurement means and from the shape of the outline ( 21 ) of the target lens ( 11 , 12 ) acquired with the help of said input or acquisition means.

16. A method according to claim 1 , including the following steps:

numerically acquiring the shape of the outline of the presentation lens ( 31 , 32 ) and the position of said outline relative to the presentation frame, by outline reading and/or feeling and/or image recognition, or on the basis of an electronic file representative of its shape and position relative to the presentation frame;

measuring, in step c), the height difference (Hb 2 ; Hsp 2 ) between the pupillary point (Pu 2 ) of the presentation lens ( 31 , 32 ) and a presentation reference point (Pref 2 ) of the outline ( 41 ) of the presentation lens ( 31 , 32 );

performing calculation, taking account of the known shape of the outline ( 41 ) of the presentation lens ( 31 , 32 ) and of the known position of said outline ( 41 ) relative to the presentation frame ( 33 ), to deduce the height (H 2 ; H′ 2 ) of said presentation reference point (Pref 2 ) in the frame of reference associated with the presentation frame ( 33 ); and

deducing therefrom the height (h) of the pupillary point (Pu 2 ) of the presentation lens ( 31 , 32 ) in the frame of reference of the presentation frame ( 33 ).

17. A method according to claim 8 , in which the presentation reference point (Pref 2 ) associated with the presentation lens ( 31 , 32 ) is the lowest point of the outline ( 41 ) of the presentation lens ( 31 , 32 ).

18. A method according to claim 8 , in which the presentation reference point (Pref 2 ) associated with the presentation lens ( 31 , 32 ) is the point of the outline of the presentation lens ( 31 , 32 ) that is situated vertically below the pupillary point (Pu 2 ).

19. A method according to claim 16 , in which the presentation reference point (Pref 2 ) associated with the presentation lens ( 31 , 32 ) is the lowest point of the outline ( 41 ) of the presentation lens ( 31 , 32 ).

20. A method according to claim 16 , in which the presentation reference point (Pref 2 ) associated with the presentation lens ( 31 , 32 ) is the point of the outline of the presentation lens ( 31 , 32 ) that is situated vertically below the pupillary point (Pu 2 ).