Ophthalmic device with improved amplitude variation cell
The invention relates to an ophthalmic device including an electrically controllable amplitude variation cell, in particular an electrochromic transmission variation cell. More particularly, the cell ( 3 ) comprises a main convex surface on the front. This arrangement makes it possible for the cell to process a lateral luminous flux (RP), unlike cells in the prior art ( 1 AA).
1. An ophthalmic device comprising:
a cell of electrically controllable variable amplitude, the cell comprising at least a first transparent layer front-side and a second transparent layer back-side, the first and second layers defining therebetween a cavity, the first transparent layer having a main surface, exterior to the cavity, that is convex,
wherein the ophthalmic device includes at least one transparent insert, adhesively bonded to the first and/or second transparent layers of the cell and has an optical power chosen according to an ophthalmic prescription of a wearer of the device.
2. The device as claimed in claim 1 , wherein the cavity has, to within 30%, a constant spacing between said first and second layers.
3. The device as claimed in claim 1 , wherein the cavity is closed and filled with an electrochromic solution, connected to a processing circuit for setting an optical amplitude of the cell.
4. The device as claimed in claim 1 , wherein a face internal to the cavity of at least one of the transparent layers is covered with a conductive coating made of indium tin oxide.
5. The device as claimed in claim 1 , wherein the cell is of electrically controllable variable transmission in order to be, in the visible spectrum:
higher than 80% in a first state, and
lower than 30% in a second state.
6. The device as claimed in claim 5 , wherein the cell is of electrically controllable variable transmission in order to be, in the visible spectrum:
higher than the 85%, in the first state.
7. The device as claimed in claim 5 , wherein the cell is of electrically controllable variable transmission in order to be, in the visible spectrum:
lower than 18%, in the second state.
8. The device as claimed in claim 1 , wherein the cell is connected to a control circuit via a connecting element of thickness smaller than 5 μm and of width smaller than 1000 μm.
9. The device as claimed in claim 1 , furthermore including a frame comprising at least one aperture housing said cell and having a convex curvature front-side, wherein the convex main surface of said transparent layer has a curvature corresponding to the curvature of the frame.
10. The device as claimed in claim 1 , wherein the cell includes at least one transparent layer of curvature chosen to endow the cell with an optical power respecting an ophthalmic prescription of a wearer of the device.