Method for coating lenses with lenslets with an improved control on power shift
The disclosure relates to a method for coating an optical lens having a main surface at least partly covered with lenslets. The optical lens is dipped in a coating fluid, withdrawn to reach an initial position defined so that said main surface faces towards a first, horizontal, direction, and the coating fluid coating said optical lens is dried. After withdrawing the optical lens and before or while drying the coating fluid, the optical lens is tilted to a final position defined so that said main surface faces upwards towards a final direction having an angle comprised between 80° and 100° with respect to the first direction, the first and final directions defining a vertical plane. Alternately or in combination, while withdrawing said optical lens, part of the coating fluid is removed from the optical lens by sliding said optical lens along a mechanical blade.
1 . A method for coating an optical lens having a main surface at least partly covered with lenslets, the method comprising:
dipping said optical lens in a coating fluid;
withdrawing said optical lens from the coating fluid to reach an initial position defined so that said main surface faces towards a first, horizontal, direction; and
drying the coating fluid coating said optical lens;
wherein the method comprises, after withdrawing the optical lens and before or while drying the coating fluid, tilting the optical lens to a final position defined so that said main surface faces upwards towards a final direction having an angle comprised between 80° and 100° with respect to the first direction, the first and final directions defining a vertical plane.
2 . The method according to claim 1 , wherein tilting the optical lens to the final position comprises:
tilting the optical lens from the initial position to an intermediate position defined so that said main surface faces upwards towards a second direction within said vertical plane, the second direction having an angle comprised between 105° and 125° with respect to the first direction, then
tilting the optical lens from the intermediate position to the final position.
3 . The method according to claim 1 , wherein withdrawing the optical lens from the coating fluid is conducted at a constant withdrawal speed.
4 . The method according to claim 1 , wherein withdrawing the optical lens from the coating fluid is conducted at a progressively decreasing withdrawal speed.
5 . The method according to claim 1 , wherein the method comprises, after withdrawing and before tilting the optical lens, waiting a predetermined amount of time equal to at most 3 seconds to allow part of the coating fluid coating the optical lens to drip.
6 . The method according to claim 1 , wherein tilting the optical lens is conducted according to a smooth continuous movement.
7 . The method according to claim 1 , wherein drying the coating fluid coating the optical lens comprises controlling a temperature at the main surface of the optical lens.
8 . The method according to claim 1 , wherein drying the coating fluid coating the optical lens comprises controlling a gas flow rate at the main surface of the optical lens.