Package inspection system

• US 4,972,494 A
• Filed: 09/22/1988
• Issued: 11/20/1990
• Est. Priority Date: 02/26/1988
• Status: Expired due to Fees

• Current Assignee: R J Reynolds Tobacco Company (R. J. Reynolds Tobacco)
• Original Assignee: R J Reynolds Tobacco Company (R. J. Reynolds Tobacco)
• Inventors: Wright, David L., Madding, James G. Jr., deMey, Charles F. III, Hawley, Nancy H., Clark, Shannun W., Collett, William R., White, Kenneth W., McConnell, Bain C., Henderson, Calvin W., Lassiter, Wallace R., Warren, Michael A.
• Primary Examiner(s): Boudreau, Leo H.
• Assistant Examiner(s): Razavi, Michael
• Application Number:
  US07/247,556
• Time in Patent Office: 789 Days
• Field of Search: 209/535, 250/223 R, 250/223.2, 382/8, 382/12, 358/106, 358/105, 358/107
• US Class Current: 382/143
• CPC Class Codes: B65B 19/28 Control devices for cigarette or cigar packaging machines
• CPC Class Codes: G06T 2207/30108 Industrial image inspection
• CPC Class Codes: G06T 7/001 using an image reference approach

Abstract

The invention provides package inspection systems which are capable of high speed sensing and evaluation of package integrity as packages are continuously conveyed in the manufacturing process. The systems are capable of measuring predetermined parameters of packages, e.g. cigarette packages, comparing the measured parameters with predetermined values, evaluating from the measured parameters the integrity of the packages and determining whether such packages are acceptable or, alternatively, should be rejected. The system can additionally obtain and store data on sensed package parameters for evaluating long-term and short-term manufacturing trends. In various embodiments of the invention, the system can inspect a single or plural package side(s), employing a single or plural line scan or area array camera(s) and may employ special optics to enable plural package side images to be obtained using a single camera. The invention also provides improved conveying systems for package inspection and master part detect systems which can be employed to obviate the need for synchronization between the inspection system and the conveying system.

Claims

1. An apparatus for evaluation for positional integrity of packaging elements in a package structure comprising:

(a) a package inspection station including an inspection wall;

(b) a conveyor for transporting a plurality of spaced identical packages sequentially along a conveying path through said inspection station and past said inspection wall, said inspection being positioned vertically of and adjacent said conveying path; and

(c) retaining means at said inspection station for urging said packages against said inspection wall as said packages pass through said inspection station to thereby provide constant positional alignment of said packages against said inspection wall;

(d) a position sensor to detect the presence of the package structure to be evaluated at the package inspection station, and to produce a sensing signal;

(e) at least one light source to illuminate the package structure;

(f) recording means comprising at least one camera which responds to said sensing signal to produce camera output signals representing images of the package aligned against said inspection wall at the package inspection station, at least one camera being optically perpendicularly aligned to a surface of the package and said inspection wall while obtaining said package images; and

(g) analysis means responsive to the camera output signals for evaluating said package images.

2. The apparatus as defined in claim 1 wherein the light source is a polarized light source.

3. The apparatus as defined in claim 2 wherein said recording means includes a polarizing filter which is cross polarized to the polarized light source.

4. The apparatus as defined in claim 1 wherein said package inspection station contains a rear wall retaining guide having a light colored portion and a dark colored portion.

5. The apparatus as defined claim 1 wherein said analysis means is a computer.

6. The apparatus as defined in claim 1 wherein said package structure is a cigarette package.

7. The apparatus of claim 1, wherein said camera is a line scan camera.

8. The apparatus of claim 1, wherein said camera is a video camera.

9. The apparatus of claim 1, wherein said recording means includes a plurality of video cameras for obtaining images of corresponding surfaces of the package structure.

10. The apparatus of claim 9, wherein said analysis means includes image processor means responsive to said plurality of cameras for producing a single composite image of said package.

11. The apparatus of claim 10, wherein said analysis means includes means for comparing signals representing segments of said composite image with predetermined standard signals representing a desired package configuration and for producing error signals when the composite image of said package differs from the desired package configuration.

12. The apparatus of claim 11, wherein said light source comprises a strobe light responsive to said sensing signal to illuminate said package.

13. The apparatus of claim 1, wherein said one camera is a line scan camera, said apparatus further including:

a plurality of position detectors for sensing the position of said package structure in said inspection station and producing a plurality of corresponding position sensing signals, said line scan camera being responsive to said position sensing signals to produce line camera output signals corresponding to line images of said package structure.

14. The apparatus of claim 13, wherein said analysis means includes means for comparing standard signals representing desired pack age line scan patterns with said camera output signals and for producing error signals when said package structure line images differ from said desired package line scan patterns.

15. The apparatus as defined in claim 1 wherein the recording means is a camera which records views of one or more sides of a cigarette package.

16. The apparatus as defined in claim 1 wherein the recording means are at least two cameras which each view a separate portion of the package.

17. A package inspection system for evaluation of packages for defects comprising:

(a) conveying means for transporting a plurality of packages having proximate and remote sides along a conveying path past a single inspection station along said conveying path,

(b) a plurality of position sensors sequentially located along said conveying path to detect the presence of a package at said plurality of sequentially located positions sensors, said plurality of position sensors defining a plurality of corresponding package inspection positions at said package inspection station;

(c) trigger signal means responsive to selected ones of said plurality of position sensors for generating trigger signals;

(d) camera means responsive to said trigger signal means for producing an output signal representing on image pattern for at least a portion of one side of the package at each of said package inspection positions corresponding to said selected ones of said plurality of position sensors;

(e) storage means for recording the output signals produced by the camera means at each of said package inspection positions corresponding to said selected ones of said plurality of position sensors; and

(f) means for comparing the recorded output signals with reference pattern signals to obtain error signals representing package defects.

18. The package inspection system as defined in claim 17 wherein the camera means is at least one line scan camera.

19. The package inspection system as defined in claim 17 wherein said inspection station includes a stationary inspection wall, said plurality of package inspection positions being different package positions at said inspection wall.

20. The package inspection system as defined in claim 19 further comprising retaining means to provide constant positional alignment of said package against said inspection wall.