Abstract:
A method and system for dynamically adjusting the placement of internal content material to optimally position the content material relative to a wrapped enclosure, and obviate the requirement to out-sort the assembled envelope. Upon assembly, a detection system visually images each envelope in predetermined regions of interest (ROIs). A controller captures the image data for comparison with a set of predefined position data and issues a feedback signal indicative of a directional change which drives an error signal to zero. The correction signal is used by the phase nip roller assembly to adaptively adjust the position of the content material by incrementally adjusting, advancing or retarding, the phase-nip roller assembly, i.e., forward or aft. A predefined number of envelopes is selected to acquire a running average of the image data.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to mailpiece fabrication systems, and, more particularly, to a method and system for dynamically adjusting the position of internal content material while wrapping the content material during assembly, 
       BACKGROUND OF THE INVENTION 
       [0002]    Mailpiece fabrication systems such as mailpiece inserters and mailpiece wrappers are typically used by organizations such as banks, insurance companies, and utility companies to periodically produce a large volume of mail, e.g., monthly billing or shareholders income/dividend statements. In many respects, mailpiece inserters are analogous to automated assembly equipment inasmuch as sheets, inserts and envelopes are conveyed along a feed path and assembled in, or at, various modules of the mailpiece inserter. That is, the various modules work cooperatively to process the sheets until a finished mailpiece is produced. 
         [0003]    Mailpiece inserters include a variety of apparatus/modules for conveying and processing a substrate/sheet material along the feed path. Commonly mailpiece inserters include apparatus/modules for (i) feeding and singulating printed content in a “feeder module”, (ii) accumulating the content to form a multi-sheet collation in an “accumulator”, (iii) folding the content to produce a variety of fold configurations such as a C-fold, Z-fold, bi-fold and gate fold, in a “folder”, (iv) feeding mailpiece inserts such as coupons, brochures, and pamphlets, in combination with the content, in a “chassis module” (v) inserting the folded/unfold and/or nested content into an envelope in an “envelope inserter”, (vi) sealing the filled envelope in “sealing module” and (vii) printing recipient/return addresses and/or postage indicia on the face of the mailpiece envelope at a “print station”. 
         [0004]    In lieu of modules for inserting and/or sealing the content material into an “envelope”, some mailpiece fabrication systems employ a wrapping system operative to encapsulate the mailpiece content in an outer wrapping material or substrate. Therein, the content material is fed into a substrate/wrap having a pressure-activated adhesive deposited thereon to enclose/seal the content material in a tubular-shaped envelope wrap. More specifically, the content material is fed into a wrapping module which receives a supply of substrate material from a web of rolled material. Before being fed to the wrapping module, an adhesive application module deposits a polymeric adhesive in a predefined two-dimensional pattern on the substrate material. As the substrate material is folded by the wrapping system, an envelope pocket is produced for receipt of the content material. 
         [0005]    More specifically, the supply of substrate material is fed from beneath the deck of the wrapping module and turned downstream to define an open-end for accepting a supply of content material. As the substrate and content material is pulled downstream, a one or more guides fold the substrate material inwardly such that the outboard edge portions overlap. Furthermore, a tube-shaped wrap is produced around the content material as the substrate material is drawn together downstream of the open end. The content-filled tubular structure then is passed under a series of pressure rollers to cause the pressure-activated adhesive to form a series of individual pockets having content material in each. Thereafter, the wrapping module includes a cutting roller to separate the content-filled pockets into separate envelopes. 
         [0006]    To obtain the throughput advantages of a mailpiece fabrication system, and especially one employing a wrapping system, it is important to maintain the reliability and minimize the downtime of the fabrication system. While a variety of mailpiece fabrication errors can occur to adversely impact throughput, one of the more frequent sources originates from the handling apparatus of the wrapping module. More specifically, difficulties arise when placing the content material into the open end of the tube-shaped wrap such that the content material is placed into and remains at the proper location relative to adhesive deposited along the peripheral edges of the mailpiece. 
         [0007]    For example, if the content material shifts longitudinally, i.e., in the direction of the feed path, as the wrapping material is folded over content material, then the edges of the content material may be trapped in one of the bond lines forming the pocket of the envelope. Thereafter, when the tube-shaped wrap is rolled through the pressure rollers and cut into envelopes by the cutting roller, there is no reliable method or system to identify when an envelope has been improperly fabricated. 
         [0008]    Should a positioning error occur in the phase nip roller, many envelopes may be incorrectly fabricated before identification and eradication of the error. Inasmuch as the processing error may go unnoticed during mailpiece fabrication, the potential exists for many mailpieces may be delivered with internal content material adhesively bonded to the external wrapping material. Additionally, since the content material may prevent proper sealing of the envelope, a mailpiece may remain open during delivery. As a result, confidential or sensitive information contained in the mailpieces may be inadvertently compromised. 
         [0009]    A need, therefore, exists for a system for dynamically adjusting the position of content material to prevent the need to out-sort improperly fabricated/unsealed envelopes in a mailpiece fabrication system. 
       SUMMARY OF THE INVENTION 
       [0010]    A method and system for dynamically adjusting the placement of internal content material to optimally position the content material relative to a wrapped enclosure, and obviate the requirement to out-sort the assembled envelope. Upon assembly, a detection system visually images each envelope in predetermined regions of interest (ROIs). A controller captures the image data for comparison with a set of predefined position data and issues a feedback signal indicative of a directional change which drives an error signal to zero. The correction signal is used by the phase nip roller assembly to adaptively adjust the position of the content material by incrementally adjusting, advancing or retarding, the phase-nip roller assembly, i.e., forward or aft. A predefined number of envelopes is selected to acquire a running average of the image data. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The accompanying drawings illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description given below serve to explain the principles of the invention. As shown throughout the drawings, like reference numerals designate like or corresponding parts. 
           [0012]      FIG. 1  is a schematic top view of a mailpiece fabrication system including content fabrication modules, wrapping material preparation modules including an adhesive application and detection system, a wrapping system, content material detection and position control modules and a plurality of finishing modules. 
           [0013]      FIG. 2  is an enlarged schematic top view of the relevant portions of the mailpiece fabrication system according to the present invention including a wrapping system and a content material detection and position control system of the present invention. 
           [0014]      FIG. 3  is a broken-away perspective view of an adhesive application and detection system disposed on opposing surfaces of a mailpiece wrapping material. 
           [0015]      FIG. 4  is a graphical depiction of the absorbance of a polymer adhesive as a function of wavelength from zero to one-thousand nanometers (0 nm-1000 nm) in wavelength. 
           [0016]      FIG. 5  is a broken-away perspective view of the content material detection system according one embodiment of the invention an optical imaging system for determining the spatial relationship of the content material relative to the overlying wrapping material. 
           [0017]      FIG. 5   a  is a graphical depiction of the transmission characteristics (i.e., the percent transmission vs. wavelength in nanometers (nm)) of a high pass filter used in conjunction with the optical imaging system of the content material detection system. 
           [0018]      FIG. 6  is a broken-away perspective view of the content material detection system according to another embodiment of the invention which employs feedback from the content material detection system to incrementally adjust the longitudinal position of the content material relative to the wrapping material. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    The present invention is directed to a system and method for dynamically positioning the placement of content material into a wrapping system. envelopes for use in a mailpiece fabrication system. The method/system examines each envelope in predetermined regions of interest to determine the spatial relationship between the internal content material and one or more points of reference indicative of the internal bounds of a sealing adhesive. While the invention is described in the context of a paper-based wrapping system, i.e., a system which is fed by a paper web, for creating finished mailpieces, the invention is equally applicable to other mailpiece fabrication systems wherein adhesive is applied to a substrate material used to produce an envelope. Consequently, the detailed description and illustrations are merely indicative of an embodiment of the invention, and, accordingly, the invention should be broadly interpreted in accordance with the appended claims. 
         [0020]    Before discussing some of the more relevant details of the system and method of the present invention, a brief overview of a mailpiece fabrication system will be provided.  FIGS. 1 and 2  depict a schematic block diagram of a mailpiece fabrication system  10  according to the present invention wherein: (i) a supply of content material  212  is produced by a variety of upstream content fabrication modules  200 , (ii) a wrapping system  300  receives a supply of wrapping material  412 , i.e., from a plurality of wrapping material preparation modules  400 , and (iii) a plurality of finishing modules  500  complete the mailpiece fabrication process including weighing, metering and printing postage indicia on each wrapped envelope. Before the supply of wrapping material  412  is conveyed to the wrapping system  300 , an adhesive application system  600  and adhesive detection system  700  prepare the substrate material  414  for being wrapped/sealed around the content material  212 . More specifically, the adhesive application system  600  deposits a sealing adhesive  612  (see  FIG. 3 ) about the periphery of the envelope  14  to wrap and enclose content material  212  therein. 
         [0021]    The output of the wrapping system  300  is a series of wrapped envelopes  14  which, if properly wrapped, proceed to the finishing modules  500  where delivery data such as a mailpiece destination/return address is added. According to one embodiment of the invention, a content material detection system  100  is provided to examine the spatial relationship of the content material  212  to the sealing adhesive  612  to determine if the content material has been properly wrapped. According to another embodiment of the invention, a position control system  800  is provided to adaptively control the position of the content material  212  relative to the sealing adhesive  612  for the purpose of ensuring the efficacy of the peripheral seal and output efficiency of the wrapping system  300 . 
         [0022]    The overall operation of the mailpiece fabrication system  10  is coordinated, monitored and controlled by a system controller  50 . While the mailpiece fabrication system  10  is described and illustrated as being controlled by a single system processor/controller  50 , it should be appreciated that each of the modules  100 - 600  may be individually controlled by one or more processors. Hence, the system controller  50  may also be viewed being controlled by one or more individual microprocessors. 
       Upstream Content Fabrication Modules 
       [0023]    In the described embodiment, the upstream content fabrication modules  200  include a feeder  210  containing a stack  214  of pre-printed sheets of content material  212 . The pre-printed sheets of content material  212  are separated in the feeder  210  by a singulating apparatus  216  which uses a combination of guides  217 , drive belts  218 , and a stone roller  219  to retard the upper portion of the stack  212  while the lowermost sheet in the stack  212  is “singulated” or separated from the underside of the stack  212 . 
         [0024]    Next, the content material  212  is conveyed to a scanner  220  which reads information contained on select sheets of the content material  212  to provide mailpiece processing information to the controller  50 . For example, a Beginning Of Collation (BOC) mark  222  may be read by a scanner  224  to indicate which sheet of content material  212 , in a series of sheets being conveyed along a feed path FP, is the first sheet of a collation. These marks  222 , also known as scan codes, are typically located in the margins of the content material  212  and are used to provide a myriad of information relating to the subsequent processing of the content material  212 . 
         [0025]    Scan codes  222  can provide information regarding whether a particular collation is to be folded, stitched, or stapled. Alternatively, a scan code can provide information regarding whether a particular mailpiece insert will be added to a particular sheet of content material  212  or to a collation of sheets of content material  212 . Additionally, the scan code can provide information regarding the type of mailpiece being fabricated, i.e., whether the content material contains sensitive or confidential information. For example, some content material  212  may contain a recipient&#39;s social security number, credit card account information or private health information (protected under the HIPPA laws). 
         [0026]    Once scanned, the sheets of content material  212  may then be grouped in an accumulator module  230  to produce a stacked collation of content material  212 . A collation is typically produced by retarding the motion of select sheets in a pocket  232  of the accumulator module  230 . Accordingly, the large stack of pre-printed sheets  212  which was singulated upstream by the feeder  210  may now be grouped together in smaller stacks to form one or more collations. 
         [0027]    The content material  212 , whether stacked into a collation or remaining as a single sheet, may be conveyed to a folding module  240  operative to fold the content material into a particular fold configuration. More specifically, the folding module  240  manipulates the content material around a plurality of press rollers  242  to produce various fold configurations, e.g., a bi-fold, C-fold, Z-fold or gate-fold configuration. Depending upon the processing information obtained from the scan codes  222 , the fold module  240  may introduce a fold configuration into the content material  212  or pass the content material  212  unaffected to a chassis module  250 . 
         [0028]    The chassis module  250  performs one of the more important functions of the content fabrication modules  200  inasmuch a variety of additional information can be added to the content material  212  by way of mailpiece inserts  252 , e.g., coupons, advertisements, solicitations, etc. Therein, a mailpiece insert  252  may be added by one of a series of overhead feeders  254   a ,  254   b ,  254   c ,  254   f ,  254   e ,  254   f , and dropped onto a select piece of content material  212  as it passes beneath the overhead feeders  254   a ,  254   b ,  254   c ,  254   f ,  254   e ,  254   f . Inasmuch as the system controller  50  knows the specific processing requirements and location of each piece of content material  212 , i.e., location along the feed path, the overhead feeders  254   a ,  254   b ,  254   c ,  254   f ,  254   e ,  254   f  may selectively add inserts to build the content material  212  for a particular mailpiece recipient. For example, a specific advertisement, targeted to one mailpiece recipient, may be added by one of the feeders  254   a ,  254   b ,  254   c ,  254   f ,  254   e ,  254 , while a coupon offering may be added to the content material  212  of another mailpiece recipient by another of the feeders  254   a ,  254   b ,  254   c ,  254   f ,  254   e ,  254   f.    
         [0029]    The content material  212  is then passed to a buffer module  270  through a right angle turn module (RAT)  260 . Depending upon the space available for the various upstream content fabrication modules  200 , the RAT  260  may, or may not, be required. The buffer module  270 , on the other hand, performs another one of the more critical operations inasmuch as it serves as the “traffic manager” for the mailpiece fabrication system  10 . More specifically, the buffer module  270  employs one (1) in-feed buffer gate G 0  and five (5) buffer gates G 1 -G 5  to coordinate the timing of the content material  212  from the chassis module  250  to the wrapping system  300 . Such coordination is necessary to eliminate gaps or “dry-holes” when delivering content material  212  to the wrapping system  300 . 
         [0030]    In operation, the buffer module  270  receives input from the controller  50  regarding the flow of content material  212  from the chassis module  250  and determines the requisite speed of the wrapping system  300  to ensure that the supply of content material  212  is smooth and uninterrupted. Based upon the anticipated acceleration of the wrapping system  300 , the controller invokes various algorithms to ensure that the wrapping system  300  is not exposed to accelerations which may rupture, tear or fail the supply of wrapping material  412 . As a result reliability and throughput of the mailpiece fabrication system  10  is optimized. 
         [0031]    In addition to optimizing throughput, the buffer module  270  ensures that content material  212  is properly “matched” with a supply of pre-printed wrapping material  312  and the resulting wrapped envelope contains the content material for which it was intended. 
         [0032]    From the buffer module  270 , the content material is passed to an input conveyor  280  at a right-angle for delivery to the wrapping system  300 . The input conveyor  280  is conventional in its construction and includes pairs of drive fingers  282  which are driven by belts (also not shown) through elongate slots  284  in a transport deck  286 . The drive fingers  282  engage a trailing edge of the content material  212  to convey the content material along the deck  285 . To prevent the sudden impact of the fingers  282  from disrupting the registration of the content material  212 , the input conveyor  280  includes a pair of drive rollers (not shown) to accelerate the content material  212  before being acted on by the drive fingers  282 . That is, the drive rollers are operative to accelerate the content material  212  such that the drive fingers  282  engage the trailing edge at nearly the same speed/velocity as the content material  212 . As such, a smooth transition occurs to prevent misalignment of the content material  212 , e.g., a collation of sheets including one or more inserts, upon changing direction and velocity. 
         [0033]    The content material  212  is then conveyed downstream to a phase nip roller assembly  810 , which according to the present invention, is a component of the position control system  800 , and functions to deliver the content material  212  to the wrapping system  300 . More specifically, the phase nip roller  810  centers and matches the velocity of the content material  212  relative to the supply of wrapping material  412 . It should be appreciated that the delivery of content material  212  from the content fabrication modules  200  to the wrapping system  300  is a critical to the workings of the mailpiece fabrication system  10 . The control and timing thereof is discussed in greater detail below in a section entitled “Content Material Detection and Position Control Systems”. 
       Mailpiece Envelope System 
       [0034]    In  FIG. 2 , the wrapping system  300  receives content material from the input conveyor  280  and phase nip roller  810  of the position control system  800 . Furthermore, the wrapping system  300  receives wrapping material  412  from the wrapping material preparation modules  400 . With respect to the latter, prepared wrapping material  412  is fed to an upper conveyance deck  306  of the wrapping system  300  from a series of rollers  308  disposed beneath the deck  306 . By “prepared” is meant that the wrapping material  300  may have address or advertisement information pre-printed on a face of the wrapping material. Furthermore, the wrapping material  300  may pre-cut to a particular envelope configuration, i.e., including windows for viewing internal information printed on the wrapped content material, and/or have adhesive deposited in select areas. 
         [0035]    The wrapping material  412  is drawn vertically upward (i.e., normal to the plane of the conveyance deck  306 ), across an upstream edge  310  of the deck  306  and horizontally downstream, i.e., in the direction of arrow FD, along the surface of the conveyance deck  306 . As the wrapping material  412  is drawn over the upstream edge  310 , the outboard edge portions  412 O of the wrapping material  412  are pulled across a pair of guide rods  320  such that the outboard edge portions  412 O converge at a point P and overlap. As such, the wrapping material  412  produces an “open-end” for accepting the content material  212  from the phase nip roller  810 . Furthermore, a tube-shaped wrap  412 T is formed around the content material  212  as the wrapping material  412  is drawn together downstream of the open-end. 
         [0036]    In the described embodiment, several pieces of content material  212  have been laid into the open end of the tube-shaped wrapping material  412 T and spaced-apart by a pitch distance PI, i.e., the distance from the leading edge of one piece of content material  212   a  to the leading edge of the subsequent piece of content material  212   b . Once wrapped, the tube-shaped wrapping material  412 T is compressed by a triage of press rollers  330  to produce a strip  412 S of sealed mailpiece envelopes. The strip  414 S of sealed mailpiece envelopes is then is cut to produce individual wrapped envelopes  14  by a rotary cutter  336 . 
         [0037]    Thereafter, each of the wrapped envelopes  14  is transported from the rotary cutter  336  on a vacuum deck  338  which is controlled to separate each wrapped envelope  14  by a predetermined separation distance. Once again, the distance between successive leading edges is the pitch distance PI of the wrapped envelopes  14 . 
       Wrapping Material Preparation Module (Adhesive Application and Detection) 
       [0038]    In  FIG. 2 , the supply of wrapping material  412  is prepared as a flat-pattern substrate which is rolled into a web of substrate material  414 . The flat pattern substrate may include pre-printed information such as recipient and sender address information (not shown) or may be pre-cut to include windows (also not shown) for viewing mailpiece address information printed on the content material  212 . 
         [0039]    In the described embodiment, the substrate material  414  is conveyed over a series of re-directing rollers  308  which direct the substrate material  414  downwardly passed an adhesive application system  600  and upwardly toward the deck  306  (see  FIG. 1 ) of the wrapping system  300 . The adhesive application system  600  includes a bank of application nozzles  610  for depositing a thin line/film of adhesive  612  on the substrate material  414  as it moves passed each of the nozzles  610 . A supply of the adhesive  612  is contained in a pressure vessel  616  for feeding each of the application nozzles  610 . The vessel  616  is heated to a temperature of about two hundred degrees Fahrenheit (200° F.) by a conventional electric heating element  618  and pressurized to an internal pressure of about between about thirty to ninety PSI (30-90 lb/in 2 ) by a hydraulic pump  620 . 
         [0040]    Additionally, the application nozzles  610  are mounted to a carriage assembly  626  which moves toward or away from the substrate material  414  in the direction of arrows NM by a linear actuator  628 . More specifically, the application nozzles  610  are mounted to cross-member  632  bearing mounted to a pair of guide rails  636 . Furthermore, the guide rails  636  are orthogonal to and disposed beneath the re-directing rollers  308 . 
         [0041]    Each time the wrapping system  300  demands a supply of wrapping material  412 , the linear actuator  628  moves the bank of application nozzles  610  toward the substrate material  414  to deposit adhesive  612 . The deposition of adhesive can be as straightforward as depositing a line of a predetermined thickness on the substrate material  414  as the substrate is conveyed across the head of each nozzles  610 . Generally, the lines of adhesive  612  run parallel or orthogonal to the feed path FP of the substrate material  414 . The gaps or breaks in the lines of adhesive  612  are predefined by the mail run data, i.e., the file containing mailpiece fabrication data, and made to effect a particular seal configuration when the wrapping material  414  is folded and cut by the wrapping system  300 . Consequently, the gaps and breaks are fixed, i.e., the spacing therebetween are generally constant. 
         [0042]    Notwithstanding the conventional manner for depositing adhesive  612 , commonly owned, co-pending patent application entitled “Adaptive Adhesive Application (AAA) System”, discloses an adhesive application system  100  which is variable to improve reliability and reduce the maintenance required in connection with the wrapping system  300  and other modules  100 - 800 . More specifically, in the co-pending AAA System, the inventors discovered that by selectively controlling the nozzles  610 , and the process for depositing the adhesive, cross-contamination to other modules, e.g., the rotary cutter  336 , can be significantly reduced. 
         [0043]    Irrespective the requirement to control the flow of adhesive as described in the preceding paragraph, there is still a need to determine if the adhesive has been properly applied. For example, should the lack of adhesive prevent closure of the envelope, there is a chance that hundreds of envelopes  14  may be improperly sealed. While the lack of forming a proper enclosure may be relatively inconsequential for some envelopes  14 , for others containing confidential information, e.g., a social security number, credit card number or bank account information, the legal liabilities can be significant for the mailer. 
         [0044]    In the described embodiment and referring to  FIGS. 2 and 3 , an adhesive detection system  700  determines whether the adhesive  612  was: (i) applied to the substrate material  414 , (ii) applied at the proper location, and/or (iii) was applied in the proper quantity. The system  700  comprises a source  110  of ElectroMagnetic (EM) energy  712 , in at least the short UV range, to illuminate the surface  414   s  of the substrate material  414 , i.e., select regions  616  where the adhesive  612  is anticipated to be deposited. A source of EM energy  712  suitable for irradiating the surface  414   s  with UV light may be a short UV Light Emitting Diode (LED) or series short UV LEDs. Furthermore, a fluorescent UVC germicidal lamp may be used to illuminate the substrate  414 . Any known illumination can be used, such as, UV lasers, as long as they emit EM energy in the short UV range. By “short UV” range means between one-hundred (100 nm) to about three-hundred nanometers (300 nm). Preferably still, a short UV range means between two-hundred forty nanometers (240 nm) to about two-hundred eighty nanometers (280 nm). 
         [0045]    The wrapping material or substrate  414  is a conventional fiber reinforced, resin impregnated white paper which, when irradiated with short UVC energy, emits or fluoresces EM energy in the visible light range (i.e., a higher wavelength) of between about four-hundred nanometers (400 nm) to eight hundred nanometers (800 nm). While the wrapping material  414  emits energy in the visible light range when irradiated with short UVC energy, the polymeric adhesive  612  absorbs the most or all of the UVC energy. Consequently, the polymeric adhesive  612  can be viewed as blocking the UV energy from reaching the underlying substrate material  414 . 
         [0046]    Additionally, the system  700  includes an EM energy detection device  720  operative to detect energy  722  reflected from the surface  414   s  of the substrate material  414  in the visible light range of between about four-hundred nanometers (400 nm) to eight hundred nanometers (800 nm). An EM detection device  720  suitable for practicing the invention includes a light-to-voltage sensor used to collect the light emitted from the substrate  414  and convert the light to an analog voltage. Any other energy detection methods can be used such as, a photocathode or a CCD/Vision system. 
         [0047]      FIG. 4  depicts a graph  750  of the optical absorbance of the polymer adhesive  612 , i.e., the response detected by the EM detection device  720 , as a function of wavelength. The cross-hatched area  760  under curve reveals the absorbance of the polymeric adhesive  612  in the short UV range. In the described embodiment, the amplitude of the response reaches a maximum value of about 0.6 on a scale of energy absorbance with an adhesive film thickness of 0.05 mm using a Perkin Elmer Lambda 900 Spectrophotometer. 
         [0048]    The system controller  50 , or a processor dedicated to the adhesive detection system  700 , is operative to analyze the response of the EM energy detection device  720 . The detection system  720  determines when the EM energy  750  emitted is below a threshold level signaling the absorbance of energy by the adhesive  612 . The threshold level will generally be determined by a calibration step at system start-up, however, in the described embodiment, a threshold level of about 0.5 may be suitable for detecting the presence of adhesive on the substrate material  414 . 
         [0049]    To facilitate detection, optical brighteners are often incorporated, or can be added, into the substrate material  414  such that the combined effect augments the effectiveness of the adhesive detection system  700 . More specifically, such brighteners increase the signal that the EM detection device  720  receives. The Perkin Elmer Lambda 900, is equipped with an integrating sphere to collect all light from the sample. 
       Content Material Detection and Position Control Systems 
       [0050]    In addition to a system  700  which detects the presence, location and quantity of adhesive  612  on the substrate material  414 , the present invention monitors the efficacy, reliability and output of the wrapping system. In  FIG. 5 , a content material detection system  100  is provided comprising an imaging device  20  for optically imaging each of the wrapped envelopes  14  to determine the spatial relationship between the internal content material  414  and one or more points of reference indicative of the internal bounds of the sealing adhesive  612 , a means for providing a cue when the spatial separation between the content material  414 E and the point of reference  612 E is less than a threshold value. 
         [0051]    More specifically, the optical imaging system  20  includes a camera system  22  disposed on one side of a wrapped envelope  14  and a light source  26  disposed on the other side of the wrapped envelope  14 . The camera system  33  captures two images of each wrapped envelope  14  while the envelope  14  is in motion. The two captured images are shown in  FIG. 3  as the leading edge and trailing edge regions of interest LE ROI  and TE ROI , respectively. The displacement of individual envelopes  14  are tracked along the feed path FP using conventional photocell event/encoder based means (not shown) enabling both images to be captured at the proper envelope locations to provide the two desired leading and trailing edge regions of interest, LE ROI , TE ROI . The exposure time for each image is sufficiently small to provide a clear, non-blurred image of the moving envelope  14 . Ideally, each leading edge and trailing edge regions of interest LE ROI  and TE ROI , contains a cut envelope edge  212 E and a content material edge  412 E, with margin on either side. 
         [0052]    The light source  26  is sufficiently bright to transmit sufficient light energy to transmit across or though two thicknesses of the wrap material  412  so that the camera system  22  can detect the transmitted light energy. An optical diffuser  28  may be employed over the light source  26  to produce more uniform light before passing through the envelope  14 . Additionally, the light source  26  is sufficiently bright to enable the use of a suitably high lens “f-stop”, thereby providing an acceptable depth of field for envelopes of variable thickness. In a preferred embodiment, the light source  26  is strobed with the exposure of the camera  22 , to allow a higher illumination intensity to transmit through variable envelope thicknesses. Within the region of interest (ROI), the content material  212  will decrease the amount of light transmitted such that the content material  212  will appear darker than the surrounding area, i.e., where the thickness of the wrapping material  414  is only two sheets in thickness. 
         [0053]    Once the camera  26  captures and stores an image (i.e., commonly referred to as frame grabbing), conventional edge detection algorithms process the digital image data. In the described embodiment, the algorithms determine the edge location of the content material  212 E, the edge location of the envelope  412 E (indicative of the edge location of the sealing adhesive  612 E) and the separation distance therebetween. Examples of these separation distances are shown in  FIG. 3  as dimensions LE GAP  and TE GAP . More specifically, the separation distance LE GAP , TE GAP  may be viewed as the difference between an actual value LL ACT , TL ACT  indicative of the edge location of the content material and a predefined reference value LL MIN , TL MIN  indicative of the edge location the sealing adhesive. While the described embodiment uses an indirect point of reference, i.e., the edge location of the wrapped envelope. to define the location of the sealing adhesive, it should be appreciated that the location of the sealing adhesive may be used directly, to the extent that the imaging device  22  has the imaging power or resolution to do so. 
         [0054]    As mentioned in the preceding paragraph, the values for LL MIN , TL MIN  are predetermined for each mail run job and correspond to the distance between the envelope edge  414 E and the inboard edge of the respective adhesive strip, i.e., glue line, If either LE GAP , or TE GAP , is less than the LL MIN  or TL MIN , then the content material  212  either touches or interposes the sealing adhesive  612 . When the processor  50  determines that the spatial relationship does not meet certain predefined criteria, e.g., that the separation distance is below a threshold value, then a determination is made that the envelope  14  has not been properly wrapped. As a consequence, the envelope  14  is rejected and diverted from the feed path by an out-sort module  180 . 
         [0055]    The edge detection algorithms must measure and determine the relative positions of the content material  212 E relative to the predefined references associated with the wrapping material of the envelope  412 E and/or the sealing adhesive  612 E within a short period of time. That is, when the mailpiece fabrication system operates at full capacity, the content and wrapping materials  212 ,  414  travels at a rapid 70 cm/sec. While conventional edge detection algorithms can perform the requisite analysis and calculations within the available time period, the inventors learned that the use of certain security features know as “obfuscation patterns”, present additional challenges for the content material detection system of the present invention. In the context used herein, obfuscation patterns refer to security features printed on the inside surface of a mailpiece to prevent the human eye from reading/viewing any internal print/images internal to the mailpiece. 
         [0056]    Inasmuch as typical obfuscation patterns absorb light in the visible spectrum to prevent viewing by a human eye, these patterns are far less effective in the near-infrared region of the electromagnetic (EM) spectrum above about 920 nm in wavelength. To facilitate the continued use of conventional obfuscation patterns on wrapping material, the preferred embodiment employs a light source  26  which emits electromagnetic energy at above about nine-hundred and twenty nanometers (920 nm) in wavelength and a long band-pass filter  24  which is compatible with the light source  28  over the lens of the camera  22  of the optical imaging device 20 nm. 
         [0057]      FIG. 5   a  depicts a graph  190  of the optical characteristics of the long band-pass filler  24  wherein the filter  24  transmits ninety percent (90%) of the light energy in the region of the electromagnetic spectrum above about nine-hundred and twenty nanometers (920 nm) in wavelength and suppresses ninety-nine percent (99%) of the light energy below about eight hundred and fifty nanometers (850 nm) in wavelength. The use of these properties in connection with the optical imaging system  20  renders most obfuscation patterns ineffective and enhances the reliability of the inventive content material detection system  100 . 
         [0058]    Another benefit to the use of this wavelength relates to the elimination of eye irritation which may be caused by strobing the high intensity light source  26 . Additionally, the use of an infra-red light source  26  and long band-pass filter  24  prevents the imaging system  20  from detecting print on the outside surface of the wrapping material  412  and being mistakenly identified as an edge, i.e., of either the content or wrapping materials  212 ,  412 . 
         [0059]    The detection system  100  may also be used in conjunction with the position control assembly  800  and used to dynamically adjust the phasing relationship between the collation  212  and the wrapping material  412 . In  FIG. 6 , the content material  212  is merged with the wrapping material  412  at the open end of the tube-shaped wrap  412 T while under the positional control of the phase nip roller assembly  810 . As the content material  212  approaches the wrapping system  300 , it is travelling at a higher velocity than the wrapping material  412 . The phase nip roller assembly  810  includes a drive roller  812  rotationally mounted to a pivot arm assembly  814  capable of rotational movement in the direction of arrows PA. Furthermore, the drive roller  812  is centered within the open end  412 O of the wrapping material  412 . The roller  812  (i) receives the content material  212  from the upstream conveyor  280 , (ii) drives each piece of content material  212  into one of a series of content material stations, i.e., each station defined by and between the sealing adhesive  612   a ,  612   b , and (iii) matches the velocity of content material  212  with the that of the wrapping material  412 . The phase nip roller  812  maintains control of the content material  212  by releasing the trailing edge of the content material  212  into one of the content material stations. More specifically, a drive motor  816  drives the roller  812  in a counterclockwise direction while a linear actuator  820  releasably applies a downward force to effect engagement and release of the content material  212  into the open end  412 O of the wrapping system  300 . While the drive motor  816  may drive the roller  812  using any one of a variety of drive mechanisms, in the described embodiment, the roller  812  is driven by one or more drive belts (not shown) which wrap around the drive shaft of the roller  812 . 
         [0060]    Phasing between the content material  212  and the wrapping material  412  is presently set with a job parameter. By “phasing” is mean the timing and delivery of the content material  212  into the open end of the wrapping material  412  such that the content material is generally centered between successive strips of adhesive  612   a ,  612   b  and/or the envelope edges LE, TE which are cut downstream by the rotary cutter  336 . This predefined position data is typically determined during set up of a specific job run using a trial and error method. After a mail run job is started, there are a number of matters that can cause the content material  212  to drift from a centered location inside the tube shaped wrapping material  412 T. These include imperfect set of the job run, paper slippage at higher speeds, and elongation of the wrapping material  412  under high tensile loads. 
         [0061]    The position control system  800 , therefore analyzes the output of the content material detection system  100 , i.e., comparing the image data to the set of predefined position data, to produce a phase nip correction signal. The correction signal is used by the phase nip roller assembly  810  to adaptively adjust the position of the content material  212  by incrementally adjusting the he phase-nip roller assembly. 
         [0062]    The output of the leading and trailing edge gap values, LE GAP , TE GAP  can be processed during machine runtime to fine tune the location/placement of the content material  212  to correct for content material  212  drift while still providing the out-sort capability for envelopes that fall below one of the threshold values. For example in one implementation of the method, the use of a moving average of the leading and trailing edge gap values, LE GAP , TE GAP , may be employed. After a first number of envelopes n, of a job run, the moving averages of the leading and trailing edge gap values, LE GAP , TE GAP  are computed. The number n, can be any value, e.g., one-hundred (100) envelopes where increasing the number will reduce the rate of change of the averages. Based on the moving averages, the phase parameter can be corrected by a small amount. Thereafter, a new moving average is computed for each envelope and the phase nip correction value can be computed as follows: 
         [0000]      LE Moving Average(LE Gap1+LE Gap2+LE Gap3+ . . . LE Gap n )/ n   (Eq. 1)
 
         [0000]      TE Moving Average=(TE Gap1+TE Gap2+TE Gap3+ . . . TE Gap n )/ n   (Eq.2)
 
         [0000]      Phase Nip Correction Value=(LE Moving Average)−(TE Moving Average)  (Eq. 3)
 
         [0063]    Therefore as the content material  212  shifts downstream during a job fun the LE Moving Average will decrease and the TE Moving Average will increase. This results in a negative Phase Nip Correction Value, thereby shifting the content material  212  upstream with respect to the wrapping material  412 , in a direction towards the nominal center of the tube-shaped wrap  412 T. Similarly, as the content material  212  shifts upstream during a job, the Phase Nip Correction Value will become positive and will also shift the content material  212  towards the center of the wrapping material. 
         [0064]    Since this method always effects a shift of the content material  212  towards the center of the tube-shaped wrap  412 T, the threshold values of LL MIN  and TL MIN  can still be used as threshold values for out-sorting envelopes that are considered to have poor content material  212  placement. When the actual LE GAP  and TE GAP  values are less than these threshold values, i.e., LL MIN  and TL MIN , it is preferred to discard them for use in the moving average calculations (Equations 1 and 2), as they fall outside the scope of acceptable envelopes  14  and should not adversely effect proper content material  212  placement. 
       Finishing Modules 
       [0065]    Once the individual wrapped envelopes  14  are cut, the mailpieces are completed by a series of finishing modules  500 . The finishing modules may, inter alia, include a scale  510 , a meter  520 , a printer  520  and a tray or bin  530  for collecting the mailpieces. The scale  510  determines the weight of each mailpiece, but may also include a scanner to determine the size/volume of the mailpiece. Once the size/weight of the mailpiece has been determined a postage meter determines the postage required for delivery of the mailpiece. The printer  530  applies the postage indicia to the mailpiece and any other mailpiece information which may be required, e.g., destination and/or return address information. Finally, the mailpieces may be accumulated in a tray or bin for ease of delivery. 
         [0066]    It is to be understood that all of the present figures, and the accompanying narrative discussions of preferred embodiments, do not purport to be completely rigorous treatments of the methods and systems under consideration. For example, while the invention describes an interval of time for completing a phase of sorting operations, it should be appreciated that the processing time may differ. A person skilled in the art will understand that the steps of the present application represent general cause-and-effect relationships that do not exclude intermediate interactions of various types, and will further understand that the various structures and mechanisms described in this application can be implemented by a variety of different combinations of hardware and software, methods of escorting and storing individual mailpieces and in various configurations which need not be further elaborated herein.