Method and a device for monitoring the external integrity of cigarettes

• US 6,181,372 B1
• Filed: 06/10/1997
• Issued: 01/30/2001
• Est. Priority Date: 06/10/1996
• Status: Expired due to Fees

• Current Assignee: Gdspa
• Original Assignee: GD SPA (Is Company SRL)
• Inventors: Neri, Armando, Di Stefano, Giuseppe, Chini, Stefano
• Primary Examiner(s): Kelley, Chris S.
• Assistant Examiner(s): VO, TUNG T
• Application Number:
  US08/872,133
• Time in Patent Office: 1,330 Days
• Field of Search: H04/N.718, 348/128, 348/152, 348/159, 131/280, 131/281, 131/21.R, 250/223, 221/135, 73/82, 738/56, 209/73, 256/237
• US Class Current: 348/128
• CPC Class Codes: A24C 5/3412 by means of light, radiation or electrostatic fields A24C5/3406 takes precedence
• CPC Class Codes: G01N 21/952 Inspecting the exterior surface of cylindrical bodies or wires G01N21/956 takes precedence

Abstract

The external integrity of cigarettes is verified by a method that involves directing single cigarettes, carried on a conveyor, along a route of which one section affords a monitoring path equipped with a line scan camera; the advancing cigarette can be made selectively to rotate about its longitudinal axis while the camera, a solid state type using CCD arrays, makes a succession of scans on respective closely ordered parallel lines, which are pulsed at a programmed frequency and synchronously with the movement of the cigarette in such a way that each successive scan line will fall on one and the same generator of the cylindrical surface. Repeated scanning of the same limited surface area eliminates quality control errors attributable to the presence of particulates in the space between the cigarettes and the camera.

Claims

1. A method for monitoring the external integrity of cigarettes, comprising the steps of:

advancing single cigarettes in a predetermined feed direction by means of a conveyor, each accommodated within a relative seat afforded by the conveyor and made to follow a path of which one section is a monitoring path;

examining external characteristics of the cigarettes while in movement along the monitoring path using at least one set of multiline optical scanning means positioned along the monitoring path, such as will execute a plurality of pulsed optical scans at successive intervals;

performing each pulsed scan on a same single given generator line of the cylindrical surface of the cigarette, during the movement of the cigarette along the monitoring path, so determining a surface swept by the given generator line, the surface being formed by a cluster of parallel lines disposed one alongside another;

performing each pulsed scan by the at least one multiline optical scanner more than once, sequentially and synchronously with the movement of the same single given generator line of the cylindrical surface of the cigarette along the monitoring path in the feed direction;

comparing each scanned image of each generator line with a reference image, assigning to the image a positive mark if the scanned image is dissimilar to the reference image, and assigning a negative mark to the image if the scanned image is in accordance with the reference image;

determining a ratio between the positive marks and the negative marks of the scanned images, in the event of the ratio exceeds a reprogrammable preset value, generating an output signal; and

rejecting the corresponding cigarette if the output signal is generated.

2. A method as in claim 1, comprising the further steps of enforcing a rotation of each cigarette about its own longitudinal axis in a given direction at least when crossing the scan lines, and of synchronizing the scan lines with the movements of the cigarette along the feed direction and in rotation about its own axis in such a way that the same generator is scanned repeatedly.

3. A method as in claim 1, comprising the further steps of enforcing a rotation of each cigarette about its own longitudinal axis in a given direction at least when crossing the scan lines, and of synchronizing the scan lines with the movements of the cigarette along the feed direction and in rotation about its own axis in such a way that the same generator is scanned repeatedly, wherein the optical scanning means comprise at least one solid state camera capable of multiline scanning.

4. A method as in claim 2, wherein use is made of a plurality of optical scanning means distributed along the monitoring path, comprising the further step of causing the cigarette to rotate about its own longitudinal axis when advancing between one set of optical scanning means and the next in order to allow the examination of more than one generator presented by each cigarette.

5. A device for monitoring the external integrity of cigarettes, comprising:

a conveyor affording a plurality of seats caused to advance in a feed direction along a predetermined path of which one section is a monitoring path, each accommodating a relative cigarette disposed with its longitudinal axis transverse to the feed direction;

at least one set of optical scanning means positioned along the monitoring path and designed to examine the external characteristics of at least one generator presented by each cigarette advancing along the monitoring path, wherein the optical scanning means are of a type such as will execute a plurality of discrete scans on a respective plurality of lines disposed parallel with and alongside one another in a cluster;

timing means by which the operation of the optical scanning means is synchronized with the movement of the conveyor in such a way that the plurality of scans will fall on one and the same generator of each advancing cigarette;

a comparing device in which each scanned image of each generator line is compared with a reference image, assigning a positive mark if the scanned image is dissimilar to the reference image, and assigning a negative mark if the scanned image is in accordance with the reference image;

an output device determining a ratio between the positive marks and the negative marks of the scanned images, and generating an output signal, in the event of the ratio exceeds a reprogrammable preset value; and

a device for rejecting the corresponding cigarette if the output signal is generated.

6. A device as in claim 5, wherein the conveyor comprises a transfer wheel rotatable about its own axis, of which the periphery affords a plurality of seats accommodating the cigarettes, and means operating synchronously with the optical scanning means, by which each cigarette occupying a respective seat is caused to rotate about its own longitudinal axis when crossing the scan lines.

7. A device as in claim 5, wherein the conveyor comprises a transfer wheel rotatable about its own axis, of which the periphery affords a plurality of seats accommodating the cigarettes, and means operating synchronously with the optical scanning means, by which each cigarette occupying a respective seat is caused to rotate about its own longitudinal axis when crossing the scan lines, the optical scanning means comprising at least one solid state camera capable of multiline scanning.

8. A device as in claim 5, comprising a plurality of optical scanning means distributed along the monitoring path, serving in operation respectively to examine a single generator of each advancing cigarette, also means of conventional embodiment by which each cigarette occupying a respective seat is caused to rotate about its own longitudinal axis when advancing between one set of optical scanning means and the next.

9. A method for monitoring the external integrity of cigarettes, comprising the steps of:

advancing single cigarettes in a predetermined feed direction by a conveyor, each accommodated within a relative sea afforded by the conveyor and made to follow a path of which one section is a monitoring path;

examining external characteristics of the cigarettes while in movement along the monitoring path using at least one multiline optical scanner positioned along the monitoring path, such as will execute a plurality of pulsed optical scans at successive intervals;

performing each pulsed scan on a same single given generator line of the cylindrical surface of the cigarette, during the movement of the cigarette along the monitoring path, so determining a surface swept by the give generator line, the surface being formed by a cluster of parallel lines disposed one alongside another;

performing each pulsed scan by the at least one multiline optical scanner more than once, sequentially and synchronously with the movement of the movement of the same single given generator line of the cylindrical surface of the cigarette along the monitoring path in the feed direction;

comparing each scanned image of each generator line with a reference image, assigning to the image a positive mark if the scanned image is dissimilar to the reference image, and assigning a negative mark to the image if the scanned image is in accordance with the reference image;

determining a ratio between the positive marks and the negative marks of the scanned images, in the event of the ratio exceeds a reprogrammable preset value, generating an output signal; and

rejecting the corresponding cigarette if the output signal is generated.

10. A method as in claim 9, comprising the further steps of enforcing a rotation of each cigarette about its own longitudinal axis in a given direction at least when crossing the scan lines, and of synchronizing the scan lines with the movements of the cigarette along the feed direction and in rotation about its own axis in such a way that the same generator is scanned repeatedly.

11. A method as in claim 9, comprising the further steps of enforcing a rotation of each cigarette about its own longitudinal axis in a given direction at least when crossing the scan lines, and of synchronizing the scan lines with the movements of the cigarette along the feed direction and in rotation about its own axis in such a way that the same generator is scanned repeatedly, wherein the optical scanner comprises at least one solid state camera capable of multiline scanning.

12. A method as in claim 10, wherein use is made of a plurality of optical scanners distributed along the monitoring path, comprising the further step of causing the cigarette to rotate about its own longitudinal axis when advancing between one optical scanner and the next in order to allow the examination of more than one generator presented by each cigarette.

13. A device for monitoring the external integrity of cigarettes, comprising:

a conveyor affording a plurality of seats caused to advance in a feed direction along a predetermined path of which one section is a monitoring path, each accommodating a relative cigarette disposed with its longitudinal axis transverse to the feed direction;

at least one optical scanner positioned along the monitoring path and designed to examine the external characteristics of at least one generator presented by each cigarette advancing along the monitoring path, wherein the optical scanner is of a type such as will execute a plurality of discrete scan on a respective plurality lines disposed parallel with and alongside one another in a cluster;

a timing mechanism to synchronize the operation of the optical scanner with the movement of the conveyor in such a way that a plurality of scans will fall on one and the same generator of each advancing cigarette;

a comparing device in which each scanned image of each generator line is compared with a reference image, assigning a positive mark if the scanned image is dissimilar to the reference image, and assigning a negative mark if the scanned image is in accordance with the reference image;

an output device determining a ratio between the positive marks and the negative marks of the scanned images, and generating an output signal, in the event of the ratio exceeds a reprogrammable preset value; and

a device for rejecting the corresponding cigarette if the output signal is generated.

14. A device as in claim 13, wherein the conveyor comprises a transfer wheel rotatable about its own axis, of which the periphery affords a plurality of seats accommodating the cigarettes, and a rotating mechanism operating synchronously with the optical scanner, by which each cigarette occupying a respective seat is caused to rotate about its own longitudinal axis when crossing the scan lines.

15. A device as in claim 13, wherein the conveyor comprises a transfer wheel rotatable about its own axis, of which the periphery affords a plurality of seats accommodating the cigarettes, and a rotating mechanism operating synchronously with the optical scanner, by which each cigarette occupying a respective seat is caused to rotate about its own longitudinal axis when crossing the scan lines, the optical scanner comprising at least one solid state camera capable of multiline scanning.

16. A device as in claim 13, comprising a plurality of optical scanners distributed along the monitoring path, serving in operation respectively to examine a single generator of each advancing cigarette, and a rotating mechanism by which each cigarette occupying a respective seat is caused to rotate about its own longitudinal axis when advancing between one optical scanner and the next.

17. A method of monitoring the external integrity of cylindrical objects, comprising the steps of:

advancing single cylindrical object along a monitoring path at a determined rate by a conveyor, each cylindrical object accommodated within a relative seat of the conveyor;

examining external characteristics of at least one of the cylindrical objects using at least one multiline scanner positioned along the monitoring path, the scanner adapted to execute a plurality of pulsed scans at successive time intervals, each of the pulsed scans parallel to one another and spaced apart from each other by a determined distance;

performing a plurality of pulsed scan on the cylindrical object, object, whereby the time and distance spacing of the plurality of pulsed scans is set to correspond to the rate of movement of the cylindrical object along the monitoring path such that each of the plurality of pulsed scans falls on a same single given generator line of an external surface of the cylindrical object.

18. A method as in claim 17 and comprising the further steps of:

comparing each scanned image of the single given generator line with a reference image, assigning to the image a first mark if the scanned image is dissimilar to the reference image, and assigning a second mark to the image if the scanned image is in accordance with the reference image;

determining a ratio between a sum of the first marks and a sum of the second marks and rejecting the cylindrical object if the ratio exceeds a predetermined value.

19. A method as claim 18, comprising the further steps of:

rotating the cylindrical object cigarette at a predetermined rate about its own longitudinal axis in a given direction along a portion of the monitoring path, and

synchronizing the rate of rotation of the cylindrical object with the rate of movement along the monitoring path such that each of the plurality of pulsed scans falls on the same single given generator line of the cylindrical object.

20. A method as in claim 19, wherein use is made of a plurality of optical scanners distributed along the monitoring path, wherein the cylindrical object rotates when advancing between one optical scanner and the next in order to allow the examination of more than one line generator of the cylindrical.

21. A method as claim 20, wherein the optical scanner comprises at least one solid state camera capable of multiline scanning.

22. A device for monitoring the external integrity of cylindrical objects, comprising:

a conveyor adapted to advance at a predetermined rate in a feed direction along a predetermined monitoring path, the conveyor including a plurality of seats each adapted to accommodate a relative cylindrical object disposed with its longitudinal axis transverse to the feed direction;

at least one scanner positioned along the monitoring path adapted to examine external characteristics of at least one line generator of an external surface of a cylindrical object advanced along the monitoring path, wherein the scanner is adapted to execute a plurality of pulsed scans at successive time intervals, each of the pulsed scans parallel to one another and spaced apart from each other by a determined distance;

a timing mechanism to synchronize the operation of the optical scanner with the movement of the conveyor in such a way that the plurality of scans will fall on a same single line generator of the advancing cylindrical object.

23. A device as in claim 22 and further comprising,

a comparing device in which each scanned image of each generator line is compared with a reference image, the comparing device assigning a first mark if the scanned image is dissimilar to the reference image, and assigning a second mark if the scanned image is in accordance with the reference image;

an output device determining a ratio between a sum of the first marks and a sum of the second marks and generating an output signal if the ratio exceeds a preset value; and

a rejection device for rejecting the corresponding cylindrical object if the output signal is generated.

24. A device as in claim 23, wherein the conveyor comprises a transfer wheel rotatable about its own axis, and having at a periphery thereof a plurality of seats adapted to accommodate the cylindrical object, and a seat rotating mechanism for rotating each of the cylindrical objects at a predetermined rate about its own longitudinal axis operating synchronously with the rate of movement along the monitoring path such that each of the plurality of pulsed scans falls on the same single given line generator of the cylindrical object.

25. A device as in claim 24, and further comprising a plurality of optical scanners distributed along the monitoring path, each adapted respectively to examine a different single line generator of each advancing cylindrical object, whereby each cylindrical object is rotated by the seat rotating mechanism when advancing between one optical scanner and the next.

26. A device as in claim 25, the optical scanner comprising at least one solid state camera capable of multiline scanning.