US 11,796,418 B2
Contact lens defect analysis and tracing system
Ya'akob Bin Mohamed, Singapore (SG); and Bee Chuan Tan, Singapore (SG)
Assigned to EMAGE VISION PTE. LTD., Singapore (SG)
Filed by EMAGE VISION PTE. LTD., Singapore (SG)
Filed on Oct. 14, 2021, as Appl. No. 17/501,368.
Claims priority of application No. 10202010191P (SG), filed on Oct. 14, 2020.
Prior Publication US 2022/0178787 A1, Jun. 9, 2022
Int. Cl. G01M 11/02 (2006.01); G01N 21/958 (2006.01); G06T 7/00 (2017.01)
CPC G01M 11/0278 (2013.01) [G01M 11/0257 (2013.01); G01N 21/958 (2013.01); G06T 7/0004 (2013.01); G01N 2021/9583 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A defect analysis and tracing system for clear and cosmetic contact lenses using rear projection, comprising;
a glass cuvette curved to hold a contact lens;
a pair of illumination modules directed towards the cuvette for back and front Illumination;
a diffuser mounted on a horizontal swivel arm to aid in diffusing the Backlit illumination when required;
a rotary wheel mounted with at least two optical filters;
a first optical module focussed at the contact lens for capturing an aberration free image;
a beam splitter to split the beam of light for capturing the image by a computer at one stage and for projection of the image on to a viewing screen at the second stage;
a first camera connected to a computer for image capturing at a first stage, and second camera at a second stage for capturing images from the viewing screen;
a gauge holder for mounting a precision calibration made of glass for measurement of various dimensions and defects of the object under inspection;
a second optical module mounted after the calibration gauge to project an overlaid image of the contact lens and the calibration pattern on the gauge, on to a viewing screening;
a large viewing screen on which the image is projected for accurate measurement of various features of the contact lens.