Abstract:
A system for inspecting the closures of packaged products employing lasers and receivers to scan multiple sides of a package thereby measuring and determining a pass/fail status of a parameter of a package closure. In one embodiment, the system employs two lasers each emitting a beam that crosses one another, as well as a product inspection path.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application Ser. No. 61/409,009 filed Nov. 1, 2010 entitled Raised Vial Stopper Detection System, which is hereby incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to product packaging and, more particularly relates to the inspection of packaging closures. 
       BACKGROUND OF THE INVENTION 
       [0003]    In most industries, the quality and preservation of packaged goods depend to a large extent upon the quality of the packaging of the goods. One important aspect of package quality is the effectiveness of the closure at sealing the product in the container and protecting it from outside elements. An improperly set closure may allow air and other elements into the container and in contact with the product thereby resulting in product contamination, spoilage and/or a reduction in quality or freshness or other adverse effects. Closure set may also affect other aspects of product packaging, such as the application of a safety seal around the closure, or packaging and product stacking. 
         [0004]    Today, automation processes are commonplace for filling containers and packages with a product and securing closures on the containers and packages. Modern equipment can fill containers and apply closures at rates from 100 to 2000 containers per minute and beyond. After a product, such as a solid, liquid, or gas, is dispensed into a container and a closure is applied to the opening of the container and secured. Safety seals and/or tamper-proof devices may be applied to the container and/or closure before or after the closure is secured to the container. 
         [0005]    One example of such an automated process is the packaging and closure of pharmaceuticals and other medical related substances into vials. Medical vials are provided in a range of shapes and can be, for example, from 1 to 100 milliliters in volume. During the packaging process, a product is automatically dispersed into an empty, sterile vial; a stopper is inserted into the opening of the vial; and the stopper is secured to the vial by capping the vial and stopper with, for example, an aluminum cap or covering. The filling of the vial and the placement of the stopper in the vial are typically performed in a more highly controlled environment than the environment, such as an aseptic room, in which the stopper and vial are capped. For obvious health reasons, a significant concern within the medical industry is the sterility and maintained sterility of packaged pharmaceuticals and other medical related substances. 
         [0006]    Of growing concern is the potential contamination of packaged medical substances that may result from stoppers that are not properly set into the vial and the subsequent improper capping and contamination of the product during the capping step.  FIG. 1A  shows an example of a stopper  12  that is properly set into a vial  14 .  FIGS. 1B and 1C  show examples of stoppers  12  that are not properly set within vials  14 . Of particular note is that the stopper  12  shown in  FIG. 1A  is inserted into the vial  14  such that there is little or no gap  16  between a lower surface  22  of flange  18  of the stopper  12  and the rim  20  of the vial  14  as compared to the gaps  16  shown in  FIGS. 1B and 1C . The vial  14  and stopper  12  shown in  FIG. 1B  have a significant, substantially uniform gap  16  and the vial  14  and stopper  12  shown in  FIG. 1C  have a significant, cocked or non-uniform gap  16 . 
         [0007]    In an attempt to increase product packaging quality and safety, devices have been developed that employ vision-based techniques to monitor certain aspects of the packaged product, such as the height of a lid or cap attached to a product container; the uniformity of the lid or cap upon a container; and, in the case of medical vials, the gap between a lower surface of a stopper flange and the rim of the vial. However, vision-based systems have proved problematic for a number of reasons. First, the varying depth of field as the vial passes in front of the camera affects inspection tolerances. Second, fluctuating lighting sources affect image quality thereby leading to less repeatable data. Third, the need to image around the diameter of the vial-stopper interface requires a complex system employing multiple cameras and/or a complex imaging system. Finally, changes in vial sizes, profiles, color, and stopper shapes require alterations to the vision-based system thereby complicating set-up and operation of the system. 
         [0008]    Examples of such vision-based closure inspection systems are described in U.S. Pat. No. 6,654,117 to Reading and U.S. Pat. No. 6,473,170 to Schafer which are herein incorporated by reference. 
         [0009]    What is needed in the art is a closure monitoring system that is simple to operate and set-up; that can easily be adjusted for variation in vial shape and size; as well as stopper shape and size; that easily detects packages or vials with missing closures or stoppers; and that has increased accuracy and throughput. 
       OBJECTS AND SUMMARY OF THE INVENTION 
       [0010]    The object of the present invention is to provide a package closure monitoring system and related method that addresses the above described problems with the current art. The present invention achieves this objective by providing an inspection system for inspecting the closures of packaged products that employs one or more lasers and associated receivers to scan multiple sides of a package as a package is transposed along a product inspection path. Accordingly, the system of the present invention measures and determines the pass/fail status for certain parameters of a package closure. 
         [0011]    In one embodiment, the system employs two lasers each emitting a beam that crossed one another, as well as a product inspection path. The lasers are triggered by an encoder associated with the product inspection path. The encoder is, in turn, associated with a sensor that signals the encoder when a packaged product intended for inspection has been sensed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which 
           [0013]      FIGS. 1A-1C  are side elevation views of vials with stoppers inserted therein. 
           [0014]      FIG. 2  is a plan view of a portion of a detection system according to an embodiment of the present invention. 
           [0015]      FIG. 3  is a plan view of a portion of a detection system according to an embodiment of the present invention. 
           [0016]      FIG. 4  is a side elevation view of a portion of a detection system according to an embodiment of the present invention. 
           [0017]      FIGS. 5A and 5B  are plan views of a portion of a detection system according to an embodiment of the present invention. 
           [0018]      FIGS. 6A and 6B  are plan views of a portion of a detection system according to an embodiment of the present invention. 
           [0019]      FIGS. 7A-7C  are views of a portion of a detection system according to an embodiment of the present invention. 
           [0020]      FIG. 8  is a diagram of the relationship between various components of a detection system according to an embodiment of the present invention. 
           [0021]      FIG. 9  is a flow diagram of the logic path of a detection system according to an embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0022]    Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements. 
         [0023]    It is noted that while the following description describes the present invention with respect to the invention&#39;s application to the detection of stoppers that are improperly placed or set into vials, this particular application of the invention is described only to facilitate comprehension of the present invention and is not intended to be limiting. One having ordinary skill in the art will understand that the present invention can be used for the monitoring and detection of closures for a multitude of container types. 
         [0024]    Broadly speaking, and with reference to  FIGS. 1A-1C  and  2 , a detection system  10  measures the gap  16  between the lower surface  22  of the flange  18  of the stopper  12  and the rim  20  of the vial  14  by employing sensors and measurement devices arranged such that the presence of the vial  14  and the stopper  12  inserted into the vial  14  are detected, the stopper gap  16  is measured, and a gap pass/fail determination is made. More particularly, the system  10  employs one or more pairs of lasers and associated receivers that scan a portion of the vial  14  and stopper  12  as the vial  14  and stopper  12  are displaced across one or more light paths spanning between the one of more pairs of lasers and receivers. 
         [0025]    As shown in  FIG. 2 , in one embodiment of the present invention a detection system  10  employs a first in-feed  40  in which vial  14  is displaced in a direction indicated by arrow  42 ; a star wheel  38  that rotates in a direction indicated by the arrow  44 ; an inspection star wheel  36  that rotates in a direction indicated by the arrow  46 ; an inspection station  34  below which or through which the inspection star wheel  36  rotates; and an out-feed  48  through which vial  14  exits the system  10  in a direction indicated by arrow  50 . It will be noted that the various directions indicated by arrows  42 ,  44 ,  46 , and  50  are broadly regarded as a product inspection path. 
         [0026]    In operation, the vial  14  enters the system  10  through the in-feed  40  that, for example, leads from a lyophilyzation autoloader. The vial  14  is displaced in the direction of arrow  42  such that the vial  14  is engaged by the star wheel  38 . In certain embodiments, the vial  14  may enter the system  10  through an alternative or second in-feed  52  that, for example, leads from a liquid filler and is displaced in the direction of arrow  54  towards the star wheel  38 . Once the vial  14  is engaged by the star wheel  38 , the vial  14  is displaced by the star wheel  38  in the direction of arrow  44  towards the inspection start wheel  36 . The vial  14  is then engaged by the inspection star wheel  36  and disengaged from the start wheel  38  and is displaced by the inspection star wheel  36  in the direction of arrow  46 . While engaged by the inspection star wheel  36 , the vial  14  is displaced through or below the inspection station  34  during which time the inspection station  34  measures the gap  16  between the vial  14  and stopper  12 . 
         [0027]    If, based upon the gap measurements obtained and analyzed by the inspection station  24 , the gap  16  is determined to be within a predetermined acceptable range, the vial  14  is disengaged from the inspection star wheel  36  so as to exit the system  10  through the out-feed  48  in the direction of arrows  58  and  50 . The out-feed  48  may, for example, lead the vial to a capper station. If, based upon the gap measurements obtained and analyzed by the inspection station  24 , the gap  16  is determined to be outside of a predetermined acceptable range, the vial  14  is disengaged from the inspection star wheel  36  so as to displace the vial  14  in the direction of arrow  56  along a reject path to a reject turn table or other holding location, not shown. 
         [0028]    Turning next to the configuration and related operation of the inspection station  34 , as shown in  FIG. 3  the inspection station  34  employs a laser  60 , emitting a light along path  62  that is received by a receiver  64 . The inspection station  34  may employ one or more laser  60  and receiver  64  pairs, for example, in the embodiment shown in  FIG. 3 , the inspection station  34  employs two of the laser  60  and receiver  64  pairs positioned such that the light paths  62  of the two pairs of lasers  60  and receivers  64  cross one another to form a 90 degree angle. The laser  60  and receiver  64  pairs are further oriented such that their respective light paths  62  form an angle  70  of approximately 45 degrees with a line  66  that is substantially perpendicular to the product inspection path  68  of the vial  14  that is engaged by inspection star wheel  36  rotating in the direction of arrow  46 . For the sake of clarity,  FIG. 3  shows a single vial  14  as it is displaced along the product inspection path  68  relative to the laser  60  and receiver  64  pairs of the inspection station  34 . 
         [0029]    The laser  60  may, for example, be a laser micrometer that employs a multi-wavelength laser having a linearity of approximately plus-or-minus 0.1 percent. The receiver  64  may, for example, employ an integrated L-CCD, linearized-charged coupled device or other suitable digital imaging devices. The laser  60  and receiver  64  may, for example, have a sampling rate of 980 microseconds, a repeatability of 5 micrometers (0.02 Mil), a resolution of 5 micrometers (0.02 Mil), and employ an I-DSP parallel computing chip. Suitable laser micrometers are produced by a variety of manufacturers including the Keyence Corporation, Osaka, Japan. 
         [0030]      FIG. 4  is a simplified diagram showing the light path  62  of the laser  60  relative to the vial  14  and stopper  12  as the vial  14  is displaced through the inspection station  34 . The laser  60  and/or the receiver  64  are not shown. As shown, the light path  62  forms a defined vertical plane. As the vial  14  and stopper  12  are displaced in the direction  46  toward the stationary light path  62 , the portions of the light path  62  are disrupted or interfered by the flange  18  and the neck  24  of the stopper  12  and by the vial  14 . The gap  16  is measured based upon the portion of the light path  62  that is not disrupted by the flange  18  of the stopper  12  and the vial  14 . 
         [0031]      FIGS. 5A and 5B  show an example of the scan patterns  70  obtained from the inspection station  34  as the vial  14  is displaced through a single light path  62 . As the vial  14  travels in the direction of arrow  46  through the inspection station  34 , multiple scans take place, represented by the series of lines of a scan pattern  72 . It is noted that an individual scan pattern may, for example, comprise of 10 to 20 individual scans or, in some embodiments 1 to 100 individual scans. As a leading side  74  of the vial  14  passes through the light path  62  measurements are obtained in a first region  78 . As a trailing side  76  of the vial proceeds through the light path  62  measurements are obtained in a second region  80 . The laser  60  and receiver  64  obtain numerous measurements through the light path  62 . From these individual scan patterns, the largest measured values will be captured and used for gap pass/fail determination. 
         [0032]      FIGS. 6A and 6B  show an example of the scan patterns  70  obtained from the inspection station  34  as the vial  14  is displaced through two light paths  62 . As the vial  14  travels in the direction of arrow  46  through the inspection station  34 , the laser  60  and receiver  64  pairs obtain numerous measurements through the light path  62 . As a leading side  74  of the vial  14  passes through the light path  62  measurements are obtained in the first region  78  and a third region  82 . As a trailing side  76  of the vial proceeds through the light path  62  measurements are obtained in the second region  80  and a fourth region  84 . 
         [0033]    As will be noted, when two laser  60  and receiver  64  pairs are employed in the inspection system  34 , four approximately equally dispersed regions  78 ,  80 ,  82 , and  84  around the neck  24  of the stopper  12  are measured. It will be appreciated that increasing the number of laser  60  and receiver  64  pairs, for example from two pair, as shown in  FIGS. 3 and 6A  and  6 B, to three or four pairs will further increase the number of regions scanned and thereby the uniformity of the measurements around the neck  24  of the stopper  12 . 
         [0034]    As also shown in  FIGS. 5B and 6B , the scan patterns  72  of the regions  78 ,  80 ,  82 , and  84  do not include scans of the outermost circumference or portion of the flange  18  of the stopper  12  and, correspondently, do not include scans of the outer most circumference or portion of the rim  20  of the vial  14 . Stated alternatively, the scan patterns  72  do not sample to the outer most extremes of the flange  18  of the stopper  12  or the rim  20  of the vial  14 . As shown in  FIGS. 1A-1C  and  4 , an outer portion of the rim  20  of the vial  14  and the flange  18  of the stopper  12  may employ rounded, beveled, or otherwise non-planar transitions from a substantially horizontal plane to a substantially vertical plane. If these rounded edges are included within the scan pattern  72 , the measurements obtained approximate these edges may be greater than the proximate interior measurements and thereby adversely result in incorrect pass/fail determinations. For example, inclusion of these rounded edges may result in measurements and subsequent determination of gaps  16  that are greater or larger than is actually the circumstance. Accordingly, inclusion of the rounded edge portions may result in artificially high measurements of gaps  16  that are outside of the acceptable gap  16  threshold, thereby unnecessarily increasing the packaging loss of the product being packaged. It will be appreciated that as a greater number of laser  60  and receiver  64  pairs are employed in the inspection station  34 , the angle formed by intersecting light paths  62  of the respective pairs will decrease. 
         [0035]    In certain embodiments, for example, in applications in which the system  10  is utilized to inspect irregularly shaped and/or actuated vessels or closures, it may be desirable to position the laser  60  and receiver  64  pairs in a non-uniform or irregularly spaced orientation. 
         [0036]    In certain other embodiments, the inspection system  10  according to the present invention employs an inspection system having the above described laser  60  and receiver  64  pairs in combination with a laser line scanner. The laser line scanner is configured to scan a top surface of the stopper  12  to determine a height of the stopper  12  within the vial  14 . The top mounted laser line scanner provides a method to indirectly measure the gap  16  completely around a diameter of the vial  12 . The line scanner is mounted with the laser pointed down and the line scan perpendicular to the direction of the travel of the vial  12 . As the vial passes through the laser line, the device provides hundreds of relative height measurements across the top surface of the stopper. This is performed simultaneously with the scans performed by the laser  60  and receiver  64  pairs described above. Combined with the known gap measurements from the aforementioned scans performed by the laser  60  and receiver  64  pairs, additional gap values are extrapolated around the full diameter of the vial  12 . This provides a more detailed analysis of the entire gap  16 . Suitable laser line scanners are available from numerous sources including Micro-Epsilon, Raleigh, N.C., and Schmitt Industries, Portland, Oreg., under the Acuity product name. 
         [0037]    The detection system  10  according to one embodiment of the present invention is described in greater detail below through description of certain steps of its operation and with reference to  FIGS. 7A-7C ,  8 , and  9 .  FIGS. 7A-7C  show the progression of a vial  14  through an inspection station  34 .  FIG. 8  is a simplified diagram showing the relationship of various components of the inspection station  34 , and  FIG. 9  is a flow diagram showing a generalized logic flow diagram of the system  10 . 
         [0038]    As a starting point, once the vial  14  is engaged by the inspection star wheel  36 , the vial is displaced in the direction of arrow  46  towards the inspection station  34 . See box  110  of  FIG. 9 . As the vial  12  approaches the inspection station  34 , a sensor  86 , for example, an image or photo or optical sensor detects the leading side  74  of the stopper  12 . See box  120  of  FIG. 9 . At this point, a reference for an encoder  88  associated with the inspection star wheel  36 , for example, a high speed position tracking encoder, is set or otherwise designated to be zero or another unique identifier. See box  130  of  FIG. 9 . As the vial  12  continues to move through the inspection station  34 , the encoder  88  will increment with reference to the predetermined reference or start point. See box  140  of  FIG. 9 . When the encoder  88  of the inspection star wheel  36 , and thereby the vial  14  engaged with the inspection star wheel  36 , reaches a predetermined Start Read 1 position, a high speed count module  94  of the control system  90  triggers the lasers  60  and the receivers  64  to start scanning the vial  14  at regions  78  and  82 . See boxes  150   a,    150   b,    160   a,  and  160   b  of  FIG. 9 . 
         [0039]    Based upon the scans obtained by the lasers  60  and the receivers  64  as the vial  14  moves through the light paths  62 , an edge detection module  96  of the control system  90  will detect edge transitions created by the lower surface  22  of the flange  18  of the stopper  12  and the rim  20  of the vial  14 . See box  115  of  FIG. 9 . The lasers  60  and associated receivers  64  will also continuously measure the gap  16  and will store the greatest measured value obtained during the individual scan patterns  72  in the measurement module  92  of the control system  90 . As the vial  14  continues to move through the light path  62 , an End Read 1 position is sensed by the encoder  88 . The End Read 1 position is the point where the leading side  74  of the neck  24  of the stopper  12  enters the light path  62 . No measurements are obtained once the neck  24  of the stopper  12  is within the light path  62 . The measured gaps  16  are evaluated and stored by the control system  90 . See boxes  170   a,    170   b,    180   a,    180   b,    190   a,  and  190   b  of  FIG. 9 . 
         [0040]    As the vial  14  continues to move through the light path  62 , the vial  14  reaches the Start Read 2 position. See boxes  200   a  and  200   b  of  FIG. 9 . The Start Read 2 position is the position in which the trailing side  76  of the neck  24  of the stopper  12  passes through the light path  62 . At the Start Read 2 position the high speed count module  94  triggers the lasers  60  and associated receivers  64  to again start continuously measuring the gap  16 . See boxes  210   a  and  210   b  of  FIG. 9 . As the vial continues to move through the light path  62 , the End Read 2 position is reached at which point the high speed count module  94  will then trigger the lasers  60  and associated receivers  64  to stop scanning and will store the greatest measured values obtained during the individual scan patterns  72  in the measurement module  92  of the control system  90 . No further measurements are obtained. See boxes  220   a,    220   b,    230   a,    230   b,    240   a,    240   b,    250   a,    250   b  and  250   c  of  FIG. 9 . 
         [0041]    The Start Read 1 and 2 positions and the End Read 1 and 2 positions are predetermined values entered into the control system  90  during inspection recipe selection. As will be appreciated, these read positions are defined by the specifications of the vials  14  being packaged. For example, a recipe for a 2 milliliter vial from a first manufacturer may have a different diameter or rim width than a 2 milliliter vial obtained from a different manufacturer or from a 4 milliliter vial. Once the proper recipe has been selected, the measurement trigger or read position point data is loaded to the high speed counter module  94 . 
         [0042]    The maximum measured values for gaps  16  from each scan pattern  72  obtained from each region  78 ,  80 ,  82 ,  84 , are compared to predetermined pass/fail thresholds and the control system  90  will accept or reject the vial  14  accordingly. See boxes  260 ,  270 , and  280  of  FIG. 9 . The accept and reject status of the vial  14  is loaded into a part tracking shift register of the control system  90  to be used for vial disposition at an accept and reject station of the section system  10 . 
         [0043]    If during the inspection process, the sensor  86  fails to detect a stopper  12 , but edge detection module  94  determines the presence of an edge, a stopper presence module  98  of the control system  90  will determine that the vial  14  is missing a stopper. See boxes  290  of  FIG. 9 . The vial  14  is designated as reject—no stopper, and will be tracked and offloaded to the reject area. 
         [0044]    If an excessive number of rejects is detected, the control system  90  will generate a fault, cycle stop, and display a message indicating ‘Excessive Rejects’. 
         [0045]    During the scanning process, the control system  90  monitors the output of the edge check module  96  in order to verify proper operation of the lasers  60  and the receivers  64 . If, when the lasers  60  and the receivers  64  are triggered to scan, the edge check module  96  output does not transition, the control system  90  will generate a fault, cycle stop, and, for example, display a message indicating laser measurement failure. 
         [0046]    It will be recognized that the consistent positioning of the vial  14  within the inspection start wheel  36  is a significant factor in maintaining the accuracy and repeatability of the gap  16  measurements obtained by the system  10 . Accordingly, in certain embodiments of the present invention, the inspection star wheel  36  employs a “v” shape or a partial multisided geometric shape having planar side that taper to a common point or plane, such as a partial hexagon shaped indentions. Such recesses or indentations function to more easily position each vial  14  into the same relative position within the indentions of the wheel  36 . In certain embodiments, it may be desirable to secure the vial within the indention of the inspection star wheel  36  by engaging the vial  14  with suction or a spring biased retainer. 
         [0047]    In certain embodiments of the present invention, the inspection station  34  of the detection system  10  employs a laser controller  91  that is configured to control certain features and functionality of the laser  60  and the receivers  64 . 
         [0048]    In certain embodiments of the present invention, the control system  90  of the detection system  10  employs a programmable logic controller, PLC or an independent, printed circuit board controller. 
         [0049]    The detection system  10  of the present invention is operable to provide the following advantageous of known vision-based detection systems. The detection system  10  provides increased accuracy, having a standard deviation of 0.03 millimeters as compared to a standard deviation of approximately 0.09 millimeters, approximately one-third the standard deviation of vision/based system. 
         [0050]    The detection system  10  according to the present invention is advantageous over known vision-based inspection systems at least for the reason that the detection system  10  provides improved repeatability and accuracy. Therefore, false rejects are minimized and greater packaging efficiency is achieved. The detection system  10  is also easier to maintain than vision-based systems because the laser is less affected by outside variables such as lighting, product color variation, etc. The detection system  10  provides for simpler system set-up because vision-based systems require specific programming for every product variance. Since the detection system  10  utilizes direct measurement form lasers, the programmed solution is basically “off-the-shelf” and more robust. 
         [0051]    Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.