Patent Application
20070120312
Electronic document publishing often demands more than a stack of paper in an output tray of an office printer. Typically, a plurality of duplex printed sheets are bound into finished documents by a publishing system that prints and finishes books. Publishing systems perform operations such as collating, binding, folding, trimming, stapling, etc. These finishing operations are typically performed on all of the sheets in a book at one time, which generally requires the use of high forces and powerful motors. Consequently, the systems adapted to perform these functions are relatively expensive and often exceed the cost of other desktop or office printers. As such, known publishing systems are not generally well suited for use in low-cost desktop bookmaking.
In order to lower the cost of publishing systems, the forces within the publishing system are typically decreased or minimized. Accordingly, sheet-wise folding systems have developed in which individual sheets are folded and subsequently accumulated rather than folding the entire stack of sheets at one time. However, booklets folded by conventional low-force publishing systems oftentimes do not exhibit crisp fold lines, which contributes to the creation of undesirable pillowing or puckering of the booklet sheets around the spine of the booklet. Since pillowing is generally indicative of a low-quality booklet, a publishing system is desired that includes a folding apparatus that utilizes low magnitude forces and while also decreasing pillowing the bound documents output from the publishing system.
One aspect of the present invention relates to a book finishing station configured to process a media sheet. The book finishing station includes a support apparatus, a clamping apparatus, and a heating element. The clamping apparatus is spaced from the support apparatus. During use, a media sheet is positioned between the support apparatus and the clamping apparatus, and the support apparatus is configured to move toward the clamping apparatus to clamp the media sheet between the support apparatus and the clamping apparatus. The heating element is coupled with one of the support apparatus and the clamping apparatus and is configured to apply heat to the media sheet near a fold line defined by the media sheet.
In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “down,” “over,” “above,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
In one embodiment, finishing system 12 includes at least one finishing station configured to decrease pillowing in bound document 14 by applying heat at and/or near a fold line of individual ones or more than one of the sheets within bound document 14. In one embodiment, heat is provided at and/or near the fold line when the fold line is initially formed in each sheet. In one embodiment, heat is provided over the fold line of each sheet as it is accumulated on a stack of sheets supported over a saddle for further finishing.
The application of heat at and/or near the fold line produces an improved or more crisp fold line, which subsequently decreases pillowing in the final bound document 14. More specifically, heating the sheet generally serves to reduce rigidity of paper polymer fibers that comprise the sheet. The decreased fiber rigidity allows the sheet to be more easily manipulated or formed, in this case, folded or smoothed over other sheets. Accordingly, in one embodiment, when the sheet fibers are heated the fold line can be more crisply defined and/or the sheet can be more smoothly formed over other sheets in a sheet stack. When the fold of the sheet and/or the extension of the sheet on the sheet stack are improved, the amount of pillowing in the associated bound document being formed is decreased accordingly.
In one embodiment, the moisture content of the sheet may also be altered to increase the quality of the fold under generally lower forces. In one embodiment, the sheet may be a least partially wet prior to folding to encourage formation of more crisp fold line. In one embodiment, heating and or wetting the sheets being folded also allows thicker or coated sheets to be more easily foldable, which thereby, decreases the forces generally required to fold such sheets.
During use and as indicated by arrow 26, one or more sheets 20 are received from printer 10 (illustrated in
In one embodiment, folding station 22 includes a heating element 40, a fold blade 42, a carriage assembly 44, and a drive mechanism 46. Drive mechanism 46 is configured to move carriage assembly 44 toward fold blade 42 to fold one or more sheets 20 (illustrated in
In one embodiment, fold blade 42 is made of metal or any other suitable material and is shaped as a substantially flat strip having a generally rectangular cross-sectional profile at its free edge 48. In other embodiments, fold blade 42 is formed having other cross-sectional profiles, such as a rounded, triangular, concave, or convex cross-sectional profile, at free edge 48. In one embodiment, fold blade 42 is supported by a blade holder 50 and laterally extends in a direction substantially perpendicular to the sheet path, which is generally indicated in
In one embodiment, heating element 40 extends over free edge 48 of fold blade 42. Heating element 40 is a strip heater, a wire heater, or any other heating element suitable for providing heat to sheet(s) 20 passing through folding station 22. In one embodiment, heating element 40 is coupled to a heat or electricity source 54. In one embodiment, heating element 40 is configured to heat sheet 20 to relax the fibers of each sheet 20, thereby, permitting a sharper and more crisp fold line to be produced and pressed into each sheet 20. In one embodiment, each sheet 20 is heated to a temperature between about 150° C. and about 200° C. In one embodiment, the temperature at which sheet 20 is heated is selected to be sufficiently low to avoid reflowing toner or ink previously printed to sheets 20. In one embodiment, sheet 20 is heated to a glass transition temperature (Tg) of polymeric fiber components within the sheet, if any. The glass transition temperature is generally a temperature at which a polymeric material transitions from a hard and brittle state to a state allowing for plastic deformation of the polymeric material. In other embodiments, sheet 20 is heated to a temperature below or above the glass transition temperature of any polymeric fiber components within sheet 20.
Carriage assembly 44 extends substantially parallel to and above fold blade 42. Carriage assembly 44 is coupled with drive mechanism 46. Drive mechanism 46 is configured to selectively move carriage assembly 44 toward fold blade 42. In another embodiment, carriage assembly 44 is substantially stationary and fold blade 42 alternatively moves toward carriage assembly 44.
In one embodiment, carriage assembly 44 includes a housing 60, fold rollers 62, and one or more pinch foot 64. Housing 60 is configured to retain fold rollers 62 and at least one pinch foot 64 and is coupled with drive mechanism 46. In one embodiment, housing 60 extends parallel to fold blade 42 and is made of any suitable material, such as metal or plastic.
Fold rollers 62 are rotatably attached to an interior portion of housing 60. Two fold rollers 62 are included in the embodiment of carriage assembly 44 illustrated in
In one embodiment, no fold roller 62 is included within folding station 22. In one embodiment, carriage assembly 44 includes additional or other devices or assemblies for forming sheet 20 around fold blade 42 to form a fold within sheet 20. In one embodiment, no fold roller 62 is included in carriage assembly 44.
Each pinch foot 64 is configured to clamp against fold blade 42, and is resiliently mounted to an internal portion of housing 60. For example, each pinch foot 64 is attached to housing 60 with a pinch spring 66 as illustrated in
As illustrated in
During use of folding station 22, one or more of sheets 20 enter folding station 22 and are generally jogged and/or aligned in any suitable method to facilitate proper placement of sheet(s) 20 for folding and heating. Once sheet(s) 20 is positioned, drive mechanism 46 moves carriage assembly 44 toward sheet 20 and fold blade 42. As carriage assembly 44 is moved toward fold blade 42, sheet 20 is clamped and secured between fold blade 42 and each pinch foot 64, more particularly, pinch groove 68. In one embodiment, as carriage assembly 44 progresses further toward fold blade 42, each pinch foot 64 is forced back into housing 60 against springs 66, while maintaining pressure on sheet 20 against fold blade 42 due to the action of pinch springs 66. In one embodiment, when sheet 20 is clamped between fold blade 42 and pinch grooves 68, sheet 20 is secured relative to folding station 22 to define a fold position and to ensure proper alignment of sheet 20 relative to fold blade 42.
In one embodiment, a fold line 70 (best seen in
Upon folding sheet 20, drive mechanism 46 or other biasing force moves carriage assembly 44 away from fold blade 42, which also moves pinch foot 64 and fold rollers 62 away from fold blade 42. Although described above as moving carriage assembly 44 relative to the generally stationary fold blade 42, in other embodiments, carriage assembly 44 is substantially stationary, drive mechanism 46 is coupled to fold blade 42, and fold blade 42 is moved relative to carriage assembly 44. Other such alterations or additions to the folding station 22 described above are also contemplated.
Although described above as folding each sheet 20 in a sheet-wise manner (i.e. one sheet 20 is folded at a time), in other embodiments, any number of the plurality of sheets 20 are punched and folded at one time. In one embodiment, the number of the plurality of sheets 20 folded at one time includes more than one and less than all of sheets 20. In this respect, although the forces used to fold more than one sheet 20 are generally greater than the forces used to fold a single sheet 20, the forces are still generally smaller than conventional forces used to fold all of sheets 20 in a single operation. In one embodiment that folds a portion of sheets 20 including more than one sheet 20 at one time, the heat applied to sheets 20 may only impact one of the portion of sheets 20 (i.e., the sheet nearest fold blade 42). However, application of heat to one or more of sheets 20 still serves to increase the crispness of fold line 70 and, therefore, of spine 18 (illustrated in
As generally illustrated in
Supplemental heating apparatus 74 includes a support assembly 80, a heating element 82, and a drive mechanism 84. Support assembly 80 supports heating element 82, and drive mechanism 84 is any suitable mechanism configured to drive movement of support assembly 80 toward and away from sheets 20 accumulated on saddle 72. In one embodiment, support assembly 80 includes at least one arm 86 and a heating platform 88 that supports heating element 82. Each arm 86 is an elongated member having a first end 89 rotatably mounted to a substantially stationary frame or other member (not illustrated for clarity) within finishing system 12. Accordingly, each arm 86 is configured to rotate about the connection between arm 86 and finishing system 12 as generally indicate by arrow 90.
Heating platform 88 is secured to and extends from a second end 91 of arm 86 opposite first end 89. In one embodiment in which supplemental heating apparatus 74 includes two arms 86 spaced from one another, heating platform 88 extends between second ends 91 of the two arms 86. In one embodiment, heating platform 88 is formed in a substantially V-shape to form two planar surfaces 92 and 94 angularly positioned relative to one another to correspond with a angular geometry of saddle 72. In particular, the V-shape of heating platform 88 is configured to fit over pointed end 78 of saddle 72 and to press against any sheets 20 accumulated thereon.
Heating element 82 is any suitable element configured to provide heat to sheets 20 as will be further described below. In one embodiment, heating element 82 includes one or more pad or strip heaters 96 secured to or embedded within planar surfaces 92 and 94. In one embodiment, heating element 82 is configured to heat sheet 20 to relax the fibers of each sheet 20, thereby, facilitating formation of a more crisp fold line 70 and/or formation or smoothing of sheet 20 over other sheets 20 in sheet stack 76. In one embodiment, saddle 72 is additionally continuously or periodically heated to facilitate formation of a crisp fold line 70 in the one or more of the first sheets 20 placed on saddle 72.
In one embodiment, each sheet 20 is heated to a temperature between about 150° C. and about 200° C. In one embodiment, the temperature at which sheet 20 is heated is selected to be sufficiently low to avoid reflowing the toner or ink previously printed to sheets 20. In one embodiment, heating element 82 heats sheet 20 to a glass transition temperature (Tg) of polymeric fiber components within sheet 20, if any. In other embodiments, heating element 82 heats sheet 20 to a temperature below or above the glass transition temperature of any polymeric fiber components of sheet 20. Although described above as including a heating element 40 and 82 on each of folding station 22 and sheet accumulating station 24, in one embodiment, a heating element 40 or 82 is only included in one of folding station 22 and sheet accumulating station 24.
As each sheet 20 is added to sheet stack 76 on saddle 72, supplemental heating apparatus 74 rotates, as generally indicated by arrow 90, or otherwise moves about the connection with a finishing system frame to move heating platform 88, and therefore, heating element 82 towards pointed end 78 of saddle 72. In particular, heated element 82 is moved to contact the one sheet 20 most recently disposed on saddle 72 (i.e., the outermost sheet 20). Heating element 82 applies heat to outermost sheet 20 relaxing the sheet fibers to improve fold line 70 and to smooth and form sheet 20 over any sheets 20 previously accumulated on saddle 72. In one embodiment, supplemental heating apparatus 74 is also configured to apply heat to sheets 20 with a desired pressure to further encourage formation of a well-defined fold line 70 configured to decrease pillowing of the final bound document 14.
Once heat has been applied to sheet 20 for a desired time, arm 86 rotates in the opposite direction to return to a position away from saddle 72 such that additional sheets 20 may be accumulated on saddle 72. In one embodiment, heat element 82 applies heat to sheet 20 for less than about one second. Any other suitable heating apparatus configured to move heating element 82 relative to saddle 72 in a rotational or non-rotational manner may be used as an alternative to supplemental heating apparatus 74.
Although primarily described above as applying heat from supplemental heating apparatus 74 to individual ones of sheets 20, in other embodiments, any number of the plurality of sheets 20 to be used in bound document 14 are accumulated between each application of heat from supplemental heating apparatus 74. In one embodiment, a portion of the plurality of sheets 20 including more than one and less than all of sheets 20 are positioned over saddle 72 prior to application of heat to the top sheet 20. In such an embodiment, the heat applied to sheets 20 by supplemental heating apparatus 74 may only impact one of sheets 20 (i.e., the uppermost sheet 20). However, application of heat to one or more of sheets 20 still serves to increase the crispness of fold line 70 and, therefore, of spine 18 (illustrated in
In one embodiment, once all sheets 20 have been accumulated on saddle 72 and have been heated and/or pressed by supplemental heating apparatus 74, sheet stack 76 is stapled or otherwise bound together while on saddle 72. More particularly, in one embodiment staplers (not illustrated) contact sheet stack 76 positioned over pointed end 78 to secure staples through sheet stack 76 along fold line 70. As generally indicated by exit arrow 28, once sheets 20 are bound, the plurality of sheets 20 exit sheet accumulating station 24 as bound document 14. In one embodiment, bound document 14 exiting finishing station 24 is forwarded to another finishing station or output tray 16 (illustrated in
A general method 100 of finishing a bound document 14 is illustrated in
In one embodiment, the support apparatus used in method 100 is fold blade 42, the clamping apparatus is carriage assembly 44, and sheet 20 is heated by heating element 40. In another embodiment, the support apparatus used in method 100 is saddle 72, the clamping apparatus is heating apparatus 74, and the sheet is heated by heating element 82. Use of other suitable devices as the support and clamping apparatus of method 100 are also contemplated. Although method 100 is described as finishing one sheet, it should be understood that the one sheet 20 can be finished individually or while aligned with one or more other sheets 20.
At operation 204, sheet 20 is folded at folding station 22. In particular, drive mechanism 46 drives carriage assembly 44 toward fold blade 42. As carriage assembly 44 moves toward fold blade 42, sheet 20 is pressed against and folded down around fold blade 42 by interaction with pinch foot 64 and fold rollers 62. In one embodiment, as part of operation 204, at operation 206, sheet 20 is heated by heating element 40 to increase the crispness of fold line 70 being formed in sheet 20. In one embodiment where the portion of sheets 20 is greater than one sheet 20, only a few of sheets 20 nearest the heating element 40 are influenced by heating element 40 while the other sheets 20 in the portion of sheets 20 are folded without being heated. In one embodiment, no heating element 40 is included on fold blade 42, and therefore, heat is not applied to sheet 20 during folding at operation 204.
At operation 208, sheet 20 is forwarded to sheet accumulating station 24 and is placed over saddle 72. In one embodiment, sheet 20 is placed over other sheets 20 that have been previously accumulated on saddle 72 to partially form sheet stack 76. As sheets are placed on saddle 72, sheets 20 are jogged or otherwise positioned to align the edges and/or fold lines 70 of each sheet 20 with the edges and/or fold lines of the other sheets 20. In one embodiment, operation 208 includes operation 210 in which after each sheet 20 or portion of sheets 20 is added to saddle 72, supplemental heating apparatus 74 is activated to move heating element 82 into contact with the sheet 20 that is currently positioned outermost on saddle 72.
As heating pads 96 contact outermost sheet 20, outermost sheet 20 is relaxed and formed relatively smoothly over saddle 72 or other sheets 20 positioned between outermost sheet 20 and saddle 72. As such, any puckers or other paper configurations that tend to contribute to pillowing in an end document 14 can be decreased. In one embodiment, method 200 includes heating sheets 20 at both operations 206 and 210. In other embodiments, method 200 includes heating sheets 20 at only one of operations 206 and 210.
Following operation 208, at operation 212 it is determined if all the plurality of sheets 20 to be included in bound document 14 have been folded and accumulated in sheet stack 76. If all sheets 20 have not been folded and accumulated, then operations 202, 204, 208, and 212 are repeated as necessary for another portion of sheets 20 until all sheets 20 have been folded and accumulated into sheet stack 76. In one embodiment, in which multiple portions of sheets 20 are to be included in sheet stack 76, one portion of sheets 20 is received and folded at operations 202 and 204 substantially concurrently with the placement of a different portion of sheets 20 on saddle 72 at operation 208. If, at operation 212, it is determined that all sheets 20 have been folded and accumulated into sheet stack 76 as desired, method 200 continues to operation 214.
At operation 214, sheet stack 76 is bound with staples, adhesive, or other suitable binding device or compound. Once sheet stack 76 is bound, bound document 14 is formed and output to an output tray 16 (illustrated in
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for or combined to form variations of the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
