Image analysis – Applications – Manufacturing or product inspection
Patent
1994-02-22
1996-09-03
Mancuso, Joseph
Image analysis
Applications
Manufacturing or product inspection
382141, 382149, G06K 900
Patent
active
055531580
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a data processing device for images of an article having an axis of rotation, applicable in particular to the inspection of machined parts, food cans and beer cans.
2. Description of the Related Art
Devices for inspection of articles of revolution known up to the present time generally have a linear camera which receives an image of a generatrix of the revolving article and thresholds, generally two in number, common to all the photosensitive points of the linear camera. If the thresholds are exceeded an error signal is output.
These devices therefore require an initial calibration for each series of identical articles treated and a recalibration upon every change in series. Furthermore, the light illuminating the article must be of uniform intensity and isotropic. Otherwise, the reflections of light off of the articles cause detections of defects and produce an erroneous inspection result.
For these various reasons, the devices known at the present time are limited to a rough inspection which tolerates the less noticeable defects of relatively cylindrical articles which do not have convergent reflections.
The amount of image data to be treated during an inspection excludes the use of data processing software which uses all of the image data.
SUMMARY OF THE INVENTION
The present invention is directed at overcoming these drawbacks by providing a device which stores, for each photosensitive point of the image detector, the average of the brightnesses observed during a complete revolution of the article inspected and applies thresholds as a function of this average.
In this way, reflections are compensated for and calibration of the device is not necessary.
The object of the present invention is thus a data device for processing the data of linear images of generatrices of an article having an axis of revolution, the images being detected by a linear image detector having photosensitive points and the device being characterized by the fact that it has a memory and a calculator, the calculator being adapted to calculate, for each point of the linear image detector, data values of images coming from the point during a complete revolution of the article and to store the average value in the memory.
The description which follows, read with reference to the accompanying drawing and given by way of illustration and not of limitation, will make it possible better to understand the advantages, purposes and characteristics of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a schematic view of a system for the inspection of bodies of revolution which incorporates the device in accordance with the invention;
FIG. 2 shows an electronic diagram of the device according to the invention .
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to FIG. 1, a linear camera 1 having a linear image detector 3 and a lens 2 is provided for forming an image of a generatrix of an article of revolution 4 on the image detector 3. The article 4, which has an axis of revolution XX', is rotatably supported by a drive shaft 6 and rotated by a motor 5. An electronic signal connector 7 is connected, via an electric cable 9, to a signal input 8 of an analog-digital converter 16 which is electrically connected to an image data processing card 12. The image data processing card 12 is connected, by an electric cable 13, to a computer 14 having connectors 15 and to a display card 17, which is connected by a connector 10 to a monitor 11.
The linear camera 1 is electronic thereby providing through the connector 7, electronic signals representative of the image received by the image detector 3, which is linear and has photosensitive points. The lens 2 is of a known type. The image detector 3 is parallel to the axis of revolution XX' of the article 4. The motor 5 and the drive shaft 6 are of known types. The other elements are of known type, with the exception of the image data processing card 12, which i
REFERENCES:
patent: 4701612 (1987-10-01), Strugill
patent: 4941191 (1990-07-01), Miller et al.
patent: 4958223 (1990-09-01), Juvinall et al.
patent: 5034990 (1991-07-01), Klees
patent: 5204911 (1993-04-01), Schwatz et al.
patent: 5214713 (1993-03-01), Juvinall
patent: 5305391 (1994-04-01), Gomibuchi
patent: 5369713 (1994-11-01), Schwartz et al.
patent: 5392359 (1995-02-01), Futamura et al.
Est. Gilles Lerouz
Mancuso Joseph
Shalwala Bipin
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