Lens inspection
AssigneeNovartis AG
InventorsRoger Biel, Joachim Linkemann, Livio Fornasiero, Ingolf Braune
Life of this patent
Estimating the term…
Abstract
The invention enables more objective defect evaluation of ophthalmic lenses, especially contact lenses, to take place through the combination of the schlieren method with the transmitted light method, with the result that the advantages of these two different systems are combined. The schlieren method is in a position to illustrate the edge of a contact lens and its ruptures, in high contrast, for the CCD camera. Likewise, tears and surface defects can be made visible. Using the transmitted light method, the bubbles may be suitably prepared for the camera.
Claims25
Device for the automatic inspection of ophthalmic lenses, especially contact lenses, using a light source for illumination, a holding device for the lens, an observation beam with an attached imaging device for taking a picture of the lens and an image analysing equipment to further analyse the image of the lens, characterised in that the observation beam consists of a dark-field observation (2) and a bright-field observation (3), and an imaging device is attached both to the dark-field observation (2) and the bright-field observation (3), whereby the two imaging devices can simultaneously take a picture of the contact lens (4) and then pass this picture to the image analysing equipment which processes the two images.
Process for inspecting an ophthalmic lens or a contact lens (4), whereby the lens is illuminated, an image of the lens is taken by an imaging device and is subsequently analysed by image analysing equipment by automatic image-processing methods, characterised in that the lens is observed on a dark field (2) and a bright field (3) simultaneously and the images of the lens on a dark field and bright field are simultaneously taken by the imaging device and transmitted to the image-processing unit.
Dependencies are inferred from the claim text.