Optical inspection apparatus for moving articles
First Claim
Patent Images
1. An apparatus for optically inspecting articles, comprising:
- means for moving articles successively past an inspection station;
scanning camera means mounted at the inspection station for repeatedly scanning a viewing area extending transversely across the inspection station at a selected scan speed and frequency to visually inspect the articles as the articles pass through the viewing area;
means for directing radiant energy onto the articles within the viewing area;
said scanning camera means having an array of photo-electric transducers for receiving radiant energy through a viewing lens having an optical axis intersecting the viewing area, in which each photo-electric transducer is focused on a transverse segment of the viewing area for generating an electrical signal which corresponds to the magnitude of radiation received by the photo-electric transducer from its corresponding transverse segment of the viewing area;
threshold means for generating article data signals by comparing the magnitude of the electrical signal produced by each transducer and a threshold reference value;
and control means operatively connected to the scanning camera means, said control means including viewing off-axis angle correcting means for varying the relationship between the threshold reference value and the electrical signals during each scan in relation to the angular distance between the transverse segment of the viewing area corresponding to each transverse segment of the viewing area being observed by each transducer and the camera optical axis.
2 Assignments
0 Petitions
Accused Products
Abstract
An optical inspection system for articles moved by a conveyor, in which photo-electric transducers of one or more cameras are directed onto a transverse viewing area to detect light variations in individual articles. A threshold system permits correction for light signals in relation to the angular distance between the article being observed and the camera optical axis. A two-step inspection involves first detecting anomalous light levels, and subsequently detecting the size of each defect.
49 Citations
22 Claims
-
1. An apparatus for optically inspecting articles, comprising:
-
means for moving articles successively past an inspection station; scanning camera means mounted at the inspection station for repeatedly scanning a viewing area extending transversely across the inspection station at a selected scan speed and frequency to visually inspect the articles as the articles pass through the viewing area; means for directing radiant energy onto the articles within the viewing area; said scanning camera means having an array of photo-electric transducers for receiving radiant energy through a viewing lens having an optical axis intersecting the viewing area, in which each photo-electric transducer is focused on a transverse segment of the viewing area for generating an electrical signal which corresponds to the magnitude of radiation received by the photo-electric transducer from its corresponding transverse segment of the viewing area; threshold means for generating article data signals by comparing the magnitude of the electrical signal produced by each transducer and a threshold reference value; and control means operatively connected to the scanning camera means, said control means including viewing off-axis angle correcting means for varying the relationship between the threshold reference value and the electrical signals during each scan in relation to the angular distance between the transverse segment of the viewing area corresponding to each transverse segment of the viewing area being observed by each transducer and the camera optical axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. An apparatus for optically inspecting articles to detect shade variation defects in the articles, comprising:
-
means for moving the articles in a plurality of transversely spaced lanes successively past an inspection station; two scanning cameras mounted adjacent opposite sides of the inspection station, in which the cameras have optical axes that are directed downward and oppositely inward for repeatedly scanning a viewing area extending transversely across the inspection station at a selected scan speed and frequency to visually inspect the articles as the articles pass through the viewing area; means for directing radiant energy onto the articles within the viewing area; each of said scanning cameras having an array of photo-electric transducers for receiving radiant energy from the viewing area for generating electrical signals, the magnitude of which correspond to the magnitude of radiation received by the photo-electric transducers; threshold means responsive to the magnitude of the electrical signals for generating article defect signals by comparing the magnitude of the electrical signal produced by each transducer and a threshold reference value; control means operatively connected to the scanning cameras for synchronizing the scanning of the two cameras to detect shade variation defects in the articles; said control means including; (a) memory storage means having a number of storage elements associated with each camera corresponding to a prescribed number of angular increments of the viewing area as viewed by each camera; (b) lane registration means for loading lane identification logic information into the number of storage elements in relationship to the lateral location of the lanes with respect to the angular increments; (c) memory read means for reading out the lane logic information; (d) timing means operatively connected to the scanning cameras and the memory read means for synchronizing the scanning of the viewing area by both cameras and the read out of the lane logic information; and (e) logic means responsive to the generation of the electrical signals from the scanning cameras and the reading out of the lane logic information for detecting in which lane a defective article occurs. - View Dependent Claims (13, 14, 15, 16, 17, 18)
-
-
19. An apparatus for optically inspecting articles, comprising:
-
means for moving the articles successively past an inspection station; scanning camera means mounted at the inspection station for repeatedly scanning a transverse viewing area extending transversely across the inspection station at a selected scan speed and frequency to visually inspect the articles as the articles pass through the viewing area; means for directing radiant energy onto the articles within the viewing area; said scanning camera means having an array of photo-electric transducers for receiving radiant energy through a viewing lens having an optical axis intersecting the viewing area in which each photo-electric transducer is focused on a transverse segment of the viewing area for generating an electrical signal which corresponds to the magnitude of radiation received by the photo-electric transducer from its corresponding transverse segment of the viewing area; shade comparator means for comparing the individual electrical signals generated by each transducer to a reference defect shade signal, and for generating an output signal when a defect is detected; a plurality of register means for counting output signals associated with individual articles; and size comparator means for monitoring the individual register means and for generating an electrical signal when the count for a register means exceeds a preset value. - View Dependent Claims (20, 21, 22)
-
Specification