Patent ID: 8205986

Claim:
A method for generating a trimming setpoint for trimming an ophthalmic lens ( 30 ) in order to fit it in a surround ( 21 ) of a half-rim spectacle frame ( 20 ), comprising the steps consisting in: a) acquiring the planar coordinates (ρ 1 , θ 1 ) of a plurality of first points (P 1 ) characterizing the shape of a first longitudinal profile ( 50 ) of said surround ( 21 ); b) determining the spatial coordinates (ρ 1 , θ 1 , z 2 ) of second points (P 2 ) of a second longitudinal profile ( 51 ) obtained from a projection of said first longitudinal profile ( 50 ) onto a predetermined reference surface, c) calculating the perimeter length (I 2 ) of said second longitudinal profile ( 51 ), d) determining the spatial coordinates (ρ 1 , θ 1 , z 3 ) of third points (P 3 ) of a third longitudinal profile ( 52 ) obtained from a projection of the first or of the second longitudinal profile ( 50 , 51 ) on a curved surface deduced from a shape parameter of the ophthalmic lens ( 30 ), e) correcting the spatial coordinates (ρ 1 , θ 1 , z 3 ) of the third points (P 3 ), so as to equalize the perimeter length (I 3 ) of the third longitudinal profile ( 52 ) with the perimeter length (I 2 ) of the second longitudinal profile ( 51 ), f) deducing said trimming setpoint from said corrected spatial coordinates (ρ 4 , θ 4 , z 4 ).