OPTICAL INSPECTION STATION FOR DETECTING LIGHT-REFLECTING DEFECTS

• US 20100128120A1
• Filed: 10/24/2007
• Published: 05/27/2010
• Est. Priority Date: 10/24/2006
• Status: Active Grant

• Current Assignee: Tiama
• Original Assignee: Tiama
• Inventors: Garin, Jean-Francois
• Granted Patent: US 9,885,666 B2
• Time in Patent Office: Days
• US Class Current: 348/135
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G01N 21/9054 Inspection of sealing surface and container finish

Abstract

The invention relates to an optical inspection station (1) comprising: an illumination system (6) capable of delivering a series of light beams illuminating an inspection region of the object at various angles of incidence; a camera (8) equipped with a lens for producing images of the inspection region during rotation of the object (2); and a unit for analyzing and processing the images taken by the camera so as to detect the presence of reflecting defects in the images. According to the invention, the optical inspection station includes a series of optical elements (11) for deflecting, in the air, rays reflected by the inspection region, these being placed between the inspection region and the lens so as to form, in each image, a series of views of the inspection region taken at different angles of viewing.

Claims

1. Optical inspection station (1) to detect light-reflecting defects shown by a transparent or translucent hollow object (2) driven in rotation about its axis of symmetry (A), the inspection station comprising:

a lighting system (6) able to supply a series of light beams illuminating an inspection area (Z) of the object at different angles of incidence,

a camera (8) equipped with a lens (9) producing images of the inspection area during rotation of the object,

and an analysis and processing unit of the images taken by the camera to detect the present of reflective defects in the images,

characterized in that it comprises a series of optical elements (11) deflecting into air the rays reflected by the inspection area (Z), arranged between the inspection area (Z) and the lens (9), so as to form a series of views of the inspection area in each image, these views taken at different viewing angles.

2. Optical inspection station according to claim 1, characterized in that the optical deflection elements (11) are arranged either side of the optical viewing axis (V) of the camera.

3. Optical inspection station according to claim 1, characterized in that the optical deflection elements (11) are arranged symmetrically relative to the optical viewing axis (V) of the camera.

4. Optical inspection station according to claim 1, characterized in that the optical deflection elements (11) arranged on one same side of the optical viewing axis (V) of the camera have angles of optical deflection that differ from each other.

5. Optical inspection station according to claim 1, characterized in that the optical deflection elements (11) consist of spherical lenses, cylindrical lenses, prisms or mirrors.

6. Optical inspection station according to claim 5, characterized in that the optical deflection elements (11) consist of Fresnel prisms or Fresnel lenses.

7. Optical inspection station according to claim 1, characterized in that the lighting system (6) and the optical deflection elements (11) are arranged on the same side relative to the object.

8. Optical inspection station according to claim 1, characterized in that it comprises optical deflection elements (11) arranged side by side in a horizontal direction, to detect vertical surface cracks.

9. Optical inspection station according to claim 1, characterized in that the lighting system (6) and the optical deflection elements (11) are arranged either side of the object.

10. Optical inspection station according to claim 1, characterized in that it comprises optical deflection elements (11) that are superimposed in a vertical direction, to detect horizontal surface cracks.

11. Optical inspection station according to claim 1, characterized in that the image analysis and processing unit (20) ensures a comparison between the data extracted from the views of the images taken so as to distinguish reflected beams of stationary type from those of mobile type corresponding to defects of the object.

12. Installation to inspect transparent or translucent hollow objects (2), comprising means (3) to rotate the objects, characterized in that it comprises at least one inspection station (1) conforming to claim 1.