| 摘要 |
An optical instrument includes: a collimation element (30) having a focal distance; a point light source (25-27) with a wavelength of between 700 and 1000 nm and a diameter less than or equal to a fiftieth of the focal distance, placed at a first focus of the collimation element, so that the light becomes a beam (20) of collimated light; a backscatterer (12); a support for receiving an ophthalmic lens (14), with the collimation element, support and backscatterer being placed so that the beam of collimated light encounters the lens location (15) where micro-etching is present; an image analyzing element (32) and an image capture element (31) linked to the analyzing element and including an objective lens (35) placed at a second focus of the collimation element, which objective lens is developed to provide the analyzing element with images of the backscatterer in order to identify and locate the micro-etching. |
| 主权项 |
1. An optical instrument for identifying and localizing micro-engravings (16) present on an ophthalmic lens (14), including:
a point light source; a collimating member (30), said point light source being placed at a first focal point of said collimating member (30) so that light issued from said point light source becomes, after having passed through said collimating member, a beam (20) of collimated light; a member for sending back light; a holder (13) configured to hold said ophthalmic lens (14) between said collimating member (30) and said member for sending back light; said collimating member (30), said holder (13) and said member for sending back light are placed so that the beam (20) of collimated light issued from said collimating member (30) encounters the location (15) on the ophthalmic lens (14) where micro-engravings (16) are present, passes through said ophthalmic lens (14), encounters said member for sending back light, returns toward said ophthalmic lens (14) and once again passes through said ophthalmic lens (14) then said collimating member (30); an image-exploiting unit (32); and an image-capturing unit (31) connected to said image-exploiting unit (32), which image-capturing unit (31) includes an objective (35) placed at a second focal point of said collimating member, which objective is focused so that the images delivered to the image-exploiting unit (32), which is connected to said image-capturing unit (31), contain a representation of said micro-engravings (16) allowing said micro-engravings (16) to be identified and localized;wherein:
said member for sending back light is a backscatterer (12); said objective (35) of said image-capturing unit (31) is focused in order to deliver to the image-exploiting unit (32) images of the backscatterer (12); said point light source (25-27) has a wavelength λ comprised between 700 and 1000 nm; and said collimating member has a focal length F and said point light source (25-27) has a diameter D smaller than or equal to one fiftieth of the focal length F. |
