System and method for optical reading of markings printed on a face of an ophthalmic lens

Patent metadata

Field	Value
Publication number	US-9574872-B2
Application number	US-201214365271-A
Country	US
Kind code	B2
Filing date	Nov 28, 2012
Priority date	Dec 15, 2011
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A system for the optical reading of markings printed on an ophthalmic lens ( 2 ), includes an image capture device ( 26 ), a light source ( 15 ) and a support ( 18, 31 ) which are configured so that, when the lens is received by the support with a masking element ( 39 ) which covers the markings, the source illuminates the lens while rendering the markings visible to the device; and a mobile element on which the source is fixed and which admits a retracted position where it is distanced from the support and a working position where it surrounds at least partially the support and the source looks at the support and these latter are configured so that the source illuminates a rim ( 34 ) of the lens so that the light penetrates into its mass ( 35 ) and reaches the masking element ( 33 ) through the lens.

First claim

The invention claimed is:

1. An optical system for reading marks printed on a face ( 20 ) of an ophthalmic lens ( 2 ), said system ( 1 ) comprising:
an image capturing device ( 26 );
a light source ( 15 ); and
a holder ( 18 , 31 ) for receiving said ophthalmic lens ( 2 );

with said image capturing device ( 26 ) and said light source ( 15 ) and said holder ( 18 , 31 ) being configured so that, when said ophthalmic lens ( 2 ) is received by said holder ( 18 , 31 ), said light source ( 15 ) illuminates said lens ( 2 ), thereby making said marks ( 21 - 24 ) visible to said image capturing device ( 26 );
characterized in that said system ( 1 ) furthermore comprises a movable element ( 14 ) to which said light source ( 15 ) is fastened, which movable element ( 14 ) has a working position in which said movable element ( 14 ) at least partially encircles said holder ( 18 ) and in which said light source ( 15 ) faces said holder ( 18 , 31 ), and a retracted position in which said movable element ( 14 ) is located a distance away from said holder ( 18 , 31 ), with said light source ( 15 ) and said holder ( 18 , 31 ) being configured so that, in said working position, when said ophthalmic lens ( 2 ) is received by said holder ( 18 , 31 ) with a masking element ( 39 ) that covers said marks ( 21 - 24 ), said light source ( 15 ) illuminates an edge face ( 34 ) of said lens ( 2 ) so that the light penetrates into a bulk ( 35 ) of said lens ( 2 ) and reaches said masking element ( 33 ) through said lens ( 2 ).

2. The system as claimed in claim 1 , characterized in that said light source is formed by at least one lighting strip ( 15 ) that is inclined relative to said edge face ( 34 ) of said lens ( 2 ) depending on a general inclination of said face ( 20 ) of said lens ( 2 ) provided with said printed marks ( 21 - 24 ).

3. The system as claimed in claim 2 , characterized in that said light source is formed by two lighting strips ( 15 ) arranged facing each other and on either side of said face ( 20 ) of said lens ( 2 ) provided with said printed marks ( 21 - 24 ).

4. The system as claimed in claim 1 , characterized in that said light source is formed by two lighting strips ( 15 ) arranged facing each other and on either side of said face ( 20 ) of said lens ( 2 ) provided with said printed marks ( 21 - 24 ).

5. The system as claimed in claim 1 , characterized in that said light source is formed by an annular lighting strip arranged around said lens.

6. The system as claimed in claim 1 , characterized in that said image capturing device is formed by a video camera ( 26 ) provided with an objective ( 37 ) and a sensor ( 36 ) configured to capture the light originating from said light source ( 15 ) and backscattered by said masking element ( 33 ).

7. The system as claimed in claim 1 , characterized in that said holder, in order to receive said ophthalmic lens, comprises a clamping clip ( 28 ) having an open position and a closed position and comprising a receiving space ( 29 ) provided to receive said ophthalmic lens ( 2 ) when said clip ( 28 ) is in its open position.

8. The system as claimed in claim 1 , characterized in that said holder, in order to receive said ophthalmic lens, comprises a receiving space ( 29 ) provided to receive at least partially a positioning and centering pin ( 33 ) to which is fastened said ophthalmic lens ( 2 ), with said masking element ( 33 ) being interposed between said pin ( 31 ) and said lens ( 2 ).

9. The system as claimed in claim 1 , characterized in that it furthermore comprises a reference test pattern ( 40 ) provided for calibrating said image capturing device ( 26 ).

10. The system as claimed in claim 1 , characterized in that said masking element is formed by an opaque film ( 33 ) configured to at least partially cover said face ( 20 ) of said lens ( 2 ) provided with said printed marks ( 21 - 24 ).

11. The system as claimed in claim 1 , characterized in that it furthermore comprises a frame ( 3 ) having a base ( 5 ) on which said holder ( 18 , 31 ) rests in order to receive said lens ( 2 ), and a back wall ( 7 ) connected to said base ( 5 ) and on which said image capturing device ( 26 ) is mounted, and with said movable element ( 14 ) being mounted on said frame ( 3 ).

12. The system as claimed in claim 11 , characterized in that it furthermore comprises a cover ( 4 ) having a stationary element ( 13 ) and said movable element ( 14 ) translationally movable relative to said stationary element ( 13 ), with said cover ( 4 ) having opaque walls.

13. An optical method for reading marks printed on a face ( 20 ) of an ophthalmic lens ( 2 ), using a system ( 1 ) as claimed in claim 1 , said method comprising the following steps:
providing an ophthalmic lens ( 2 ) having on a face ( 20 ) printed marks ( 21 - 24 ) covered with a masking element ( 33 );
in a retracted position of a movable element ( 14 ) of said system ( 1 ), in which position said movable element ( 14 ) is located a distance away from a holder ( 18 , 31 ) of said system ( 1 ) in order to receive said lens ( 2 ), introducing ( 101 ) said lens ( 2 ) at least partially into said holder ( 18 , 31 );
moving ( 102 ) said movable element ( 14 ) from its retracted position to a working position in which a light source ( 15 ) of said system ( 1 ), which light source ( 15 ) is borne by said movable element ( 14 ), is brought near to an edge face ( 34 ) of said lens ( 2 );
activating ( 103 ) said light source ( 15 ) in order to illuminate said edge face ( 34 ) of said lens ( 2 ) so that the light penetrates into a bulk ( 35 ) of said lens ( 2 ) and reaches said masking element ( 33 ) through said lens ( 2 ); and
capturing ( 104 ), via an image capturing device ( 26 ) of said system ( 1 ), said light that is backscattered by said masking element ( 33 ).

14. The optical reading method as claimed in claim 13 , characterized in that it furthermore comprises the following steps:
determining ( 106 ), from the image capture, a value of a positioning discrepancy (E) between said marks ( 21 - 24 ) printed on said face ( 20 ) of said lens ( 2 ) and said holder ( 18 , 31 );
comparing ( 108 ) said determined discrepancy value (E) to a preset discrepancy threshold value (ES); and
generating ( 109 ) characterizing information for an alarm when the determined discrepancy value (E) is higher than or equal to the preset discrepancy threshold value (ES).

15. The optical reading method as claimed in claim 14 , characterized in that said discrepancy value (E) is representative of a translational distance and/or a rotational distance and/or a radial distance.

16. The optical reading method as claimed in claim 15 , characterized in that said discrepancy value (E) is representative of a combination of at least two of said translational, rotational and radial distances.

Assignees

• Dubois Frederic
• Essilor Int

Inventors

• Dubois Frederic

Classifications

• G01M11/0207 Primary

  Details of measuring devices · CPC title

• G01B11/14 Primary

  for measuring distance or clearance between spaced objects or spaced apertures (G01B11/26 takes precedence; rangefinders G01C3/00) · CPC title

• G01M11/0214

  Details of devices holding the object to be tested · CPC title

• G01M11/0278

  Detecting defects of the object to be tested, e.g. scratches or dust (investigating the presence of flaws or contamination on materials by optical means G01N21/88) · CPC title