Abstract:
The system and method for binding documents as described creates documents having features such as tabs, finger indexes, tear-out cards, and windows. These features are desirable for both their appearance and functionality and are easily added to a document during sheet-by-sheet processing. A sheet-wise binding system includes a sheet transport path for transporting a plurality of printed sheets in a sheet-wise manner and a punch configured to punch a feature into at least one of the sheets traveling through the sheet transport path. A stacking system is provided for stacking the punched and unpunched sheets and a binding system for binding the stacked sheets is used to form a finished document. A controller is programed to control the sheet transport path and the punch to create the features in selected sheets and at selected locations in the sheets according to a punch schedule.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of U.S. application Ser. No. 09/831,768 filed May 14, 2001 which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a binding system for creating documents with sheet-wise formation of document features, and more particularly, the invention relates to a sheet-wise punching system for creating features such as tabs and finger indexes in the sheets of a document. 
     2. Background Information 
     Automated saddle stitch booklet makers are currently used to bind many sheets of duplex printed material into a finished booklet. The currently known booklet making machines perform operations such as stapling, folding and trimming of sheets. Generally these booklet making machines perform these functions on many sheets at a time requiring high forces, powerful motors, and dangerous cutting devices. Such booklet making machines are expensive, often exceeding the cost of desktop or office printers. As such, known booklet making machines are not well suited for use in low cost desktop booklet making. 
     Accordingly, there is a need for electronic desktop publishing machines for forming booklets which are compact, low cost, high quality and suitable for use with desktop laser and ink jet printers. 
     In conventional booklet making machines the booklets are first assembled, stapled, and folded and then the edges of the sheets are trimmed together to achieve a finished and flush edge to the sheets. The final trimming process for formation of books may also include the addition of trimmed features to the edges of the sheets, such as indexing tabs and/or finger indexes. However, the trimming of the sheets of an entire book at one time to form these indexing features requires complicated and expensive trimming equipment increasing the cost and size of a booklet maker. 
     U.S. Pat. No. 6,099,225 describes a booklet maker and a booklet making process in which sheets are trimmed by an individual sheet trimming operation to reduce the force needed for trimming. According to this booklet making process, the sheets are trimmed to length first and, then folded, assembled, and stapled. The trimming of individual sheets allows the use of smaller and less expensive trimming systems for edge trimming. 
     However, it would be desirable to provide a booklet maker which can take advantage of sheet-wise trimming with the additional option to perform trimming of individual sheets to create features, such as indexing tabs, finger indexes, tear out cards, and windows. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a sheet-wise binding system and a method of binding sheets in which features are punched into sheets in a sheet-wise manner prior to binding the sheets into a book or booklet. 
     In accordance with one aspect of the present invention, a sheet-wise binding system includes a sheet transport path for transporting a plurality of printed sheets in a sheet-wise manner, a punch configured to punch a feature into at least one of the sheets traveling through the sheet transport path, a stacking system for stacking the punched and unpunched sheets, and a binding system for binding the stacked sheets to form a finished document. A controller is programed to control the sheet transport path and the punch to punch the feature in some of the sheets and not punch the feature in others of the sheets according to a punch schedule. 
     In accordance with another aspect of the present invention, a method of binding sheets includes the steps of delivering a plurality of sheets to a punch in a sheet-wise manner; punching at least one of the sheets with the punch to form a feature according to a punching schedule; stacking punched and unpunched sheets from the punch; and binding the stacked sheets to form a document. 
     In accordance with a further aspect of the present invention, a sheet-wise binding system includes a sheet transport path for transporting a plurality of printed sheets in a sheet-wise manner, a trimmer configured to trim the edges of the sheets traveling through the sheet transport path to form a saw tooth edge feature, a stacking system for stacking the trimmed sheets, and a binding system for binding the stacked sheets to form a finished document. A controller is programed to control the sheet transport path and the trimmer to trim the edges of the sheets at a varying location according to a trim schedule to create the saw tooth edge feature. 
     The present invention provides the advantage of a more compact and less expensive apparatus for use in creating features, such as indexing tabs and finger indexes in a book or booklet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described in greater detail with reference to the preferred embodiments illustrated in the accompanying drawings, in which like elements bear like reference numerals, and wherein: 
         FIG. 1  is a perspective view of steps of formation of a tab feature on a document sheet; 
         FIG. 2  is a perspective view of a document having two tab features located at a binding station; 
         FIG. 3  is a perspective view of the steps of formation of a finger index feature on a plurality of sheets of a document; 
         FIG. 4  is a top view of the edges of a sequence of sheets forming a semi-spherical finger index feature; 
         FIG. 5  is a perspective view of a portion of a document showing the semi-spherical finger index feature; and 
         FIG. 6  is a perspective view of a portion of a document having a plurality of finger index features forming a sawtooth edge. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention relates to systems and methods for the creation of documents having features, such as tabs, finger indexes, tear out cards, and windows. The finger indexes formed by the present invention are the type which are often found in large dictionaries to allow a user to open to a particular section of the book. These finger indexes are desirable for both their decorative appearance and functionality and yet finger indexes are primarily found in expensive books due to the complex procedures for making these features. The present invention allows these finger indexes and other features to be made at a lower cost for incorporation in all kinds of documents. 
     The tabs, windows, and tear out card features formed by the present invention are particularly useful for reports, manuals, brochures, and other documents. Windows may be used for viewing a title through a front cover of a document. Tabs are used for indexing of chapters or sections. Tear out cards are commonly used to allow envelopes and postcards to be removed from a document without damaging the document. All of the punched features formed by the present invention are formed in a sheet-by-sheet or sheet-wise manner prior to binding of the sheets into a final document. In contrast, known punching methods for forming features are performed on a finished document all at once. Alternatively, some known methods require that separately prepared sheets be collated into a document prior to binding. The sheet-by-sheet formation of the punched features of the present invention can be added to a desktop publishing booklet making system with minimal additional hardware and cost. Examples of the types of booklet making systems for which the present invention is particularly useful are described in U.S. Pat. No. 6,099,225, which is incorporated herein by reference in its entirety. 
       FIG. 1  illustrates the steps for forming one or more tabs on a document sheet by punching and/or cutting away excess material to form the tabs. As shown in  FIG. 1 , a sheet  100  is passed along a sheet transport path by a precision paper drive  130  to a punch  102  used to form a tab  110  on a leading and/or trailing edge of the sheet. The punch  102  first punches material  112  at a first side of a tab  110 . In a second punching step the punch  102  is moved in a Y direction to punch material  114  at second side of the tab  110 . After punching both sides of the tab  110 , a remainder of the excess material  116  is removed by either the punch  102  or by another cutter to create an edge of the sheet  100  with a flush edge except for the extending tab  110 . The punched and trimmed excess material  112 ,  114 ,  116  cut by the punch and/or cutter is discarded. The removal of the excess material  116  which is not cut by the punch is preferably removed by a rotary or other paper trimming cutter which is a part of the sheet trimming hardware of the booklet maker. 
     The tab formation process of  FIG. 1  is performed on a printed set of sheets with some of the sheets being punched to form tabs and some of the sheets being trimmed without the formation of tabs. The printer prints information on the sheets at a known location which will become the tab  110 . Information about the location of the printed information is communicated to the binding system for formation of the tab  110  at a desired location so that the printed information appears on the tab. 
     According to one embodiment, the punching operation for formation of the tabs  110  is performed once the sheet has been positioned at a desired punch position in the sheet transport path by the precision paper drive  130 . The sheet  100  is preferably movable in an X direction substantially perpendicular to the edge on which the tab is to be formed and the punch  102  is preferably movable in a Y direction substantially parallel to the edge. The controlled motion of the sheet in the X direction locates the paper so that the cutting edge of the punch  102  is at a specified location to form the edge of the finished document. The motion of the punch in the Y direction locates the tab and allows the punch to move to both sides of the tab  110  for punching sheet material at both sides of the tab. Alternatively, the punch  102  may be movable in both the X and Y directions to position the tab  110 . 
     Alternatively, the punching may be performed by more than one punch  102 , the punch may be fixed, and/or the sheet may be moved through one or more of a plurality of punching stations. According to a further alternative embodiment, the punching operation may be performed by a single punch extending along the whole or a part of the edge and having a tab shaped cut out. 
     The punch  102 , the sheet transport path, and associated sheet advancing mechanisms  130  are controlled by a controller  120 . The controller  120  is programed with information about the sheet numbers which are selected to receive tabs  110  and the locations of the tabs on the sheets. 
     The punching system according to the present invention may include a polygonal shaped punch  102  and a punch plate  140  having a cut out  142  with a shape corresponding to the shape of the punch  102 . In accordance with the embodiment illustrated in  FIG. 1 , the punch  102  and punch plate  140  are movable in the Y direction in a coordinated manner. Alternatively, the punch plate  140  may be a fixed plate having a plurality of holes  142  to receive the punch  102 . 
     After the tab formation and trimming processes are completed, a plurality of sheets with and without tabs are assembled in a stacked arrangement at a binding station as shown in FIG.  2 . The tabs  110  are preferably preprinted with indexing information prior to cutting away the excess material to form the tabs. The tabs  110  are preferably formed on sheets of card stock or other heavy weight paper for durability with the untabed pages of the documents formed on regular paper. The card stock for the tabs can be loaded into an alternate input tray of the printer and printed along with the regular sheets. The printing and collating of the sheets is automatic and controlled by the software of the controller or the associated printer. Alternatively, the tabs  110  may be formed on sheets of the same material as the untabed pages of the document. The punching system according to the present invention eliminates the need for expensive pre-tabbed or pre-notched card stock. 
       FIG. 2  illustrates a plurality of sheets  100  with and without tabs  110  stacked on a saddle  200  for binding.  FIG. 2  illustrates a binding system in the form of a movable stapler  202  mounted on a rod  204  above the saddle  200  for stapling the folded and stacked sheets  100  at a plurality of locations along a spine of the document. The saddle  200  may include an active or passive clinch mechanism for operation with the stapler  202 . Although a stapler binding system has been shown, any of the know binding systems may be used for binding the stacked sheets including using glue or adhesive, stapling, spiral binding, plastic comb binding, and any other binding methods. 
     For the embodiment illustrated in  FIGS. 1 and 2  in which each of the sheets  100  is folded and bound at the center of the sheet the punch system should be capable of punching both the leading and trailing edges of the sheets. A punch system for punching both leading and trailing edges of the sheets is illustrated by way of example in  FIG. 3  which will be discussed below. 
       FIG. 3  illustrates the steps for formation of a finger index on a plurality of sheets of a document. As shown in  FIG. 3 , the sheets  300  are transported along a sheet transport path to the location of a leading edge punch  302  and a trailing edge punch  306  which form notches  304  and  308  on the edges of the sheets. The punches  302  and  306  are each provided with a punch plate  340  and  342  as in the embodiment of FIG.  1 . The punches  302  and  306  are controlled by a controller  320  which determines whether or not a notch is to be formed and a location for notching each sheet  300  in the Y direction based on the location of the sheet in the finished document. As shown in  FIG. 3 , the leading and trailing edges of the sheets  300  are notched by the punches  302  and  306  having polygonal shapes to create polygonal shaped finger notches or indexes on the sheets. The punches  302  and  306  may be the same shape as the punch  102  used in  FIG. 1  allowing the same punching system to be used for creating either tabs or finger indexes. 
     After the leading and trailing edges of the sheets  300  have been punched the sheets are passed to a stacking system such as a tray or saddle which collects the sheets for binding. The sheets are then bound with a binding system, such as the stapler unit shown in FIG.  2 . The last full sheet in the stack adjacent to the punched sheets forming the finger index is preferably printed to identify a chapter, section, or other location in the document. The printing in the finger index can be viewed along an edge of the completed document. Information about the location and sheet numbers of the printed finger index information is transmitted to the binding system to correctly locate the finger index notches. 
       FIGS. 4 and 5  illustrate the formation of a semi-spherical shaped finger index cavity by punching the edges of successive sheets  410 A,  410 B,  410 C with a semi-circular or circular punch positioned at a position such that a gradually changing amount of sheet material is removed. As shown in  FIG. 4 , a first sheet  410 A of the finger index  400  is positioned in the punch and punched to form a substantially semi-circular notch  404 A on the edge of the sheet. A second sheet  410 B is punched by the punch to make a smaller notch  404 B and a third sheet  410 C and subsequent sheets are punched to make progressively smaller notches  404 C. Although the notching of three sheets has been shown, any number of sheets may be notched at gradually varying notch depths to form a stack of sheets  500  with a finger index  510  as shown in FIG.  5 . The resulting finger index  510  is useful for identifying lettered or numbered sections of a document or for other indexing. For example, the finger index of  FIGS. 4 and 5  is particularly useful for dictionaries, address books, and phone books. 
       FIG. 6  illustrates a plurality of stacked sheets  600  cut to form a sawtooth effect at the edge of a document. The sawtooth index  610  shown in  FIG. 6  may be formed using the systems and methods described above with respect to  FIGS. 3-5 . By trimming the entire edge or a portion of the edge of a document the sawtooth effect can provide an easy chapter index. Printing can be done on the visible sheet to provide chapter or section information as illustrated in  FIGS. 5 and 6 . 
     The punching system and method of the present invention may be used for other notching and hole punching operations to add features to documents in a sheet-by-sheet manner. For example, the punching system and method may be used to form tear out cards or tear out pages by forming a line of perforations on a sheet. The perforations may be formed by a perforated punching wheel which operates in a manner similar to a rotary cutter or by other known punching methods. The invention may also be used to punch windows  220 , as shown in  FIGS. 1 and 2 , such as a window for viewing a title through a cover of a booklet. 
     Precision positioning for punching and/or trimming of each sheet is achieved by a sheet transport system having a precision drive system such as those used in a low cost desktop printer. The formation of features according to the present invention is preferably used in combination with a trimming operation which trims each sheet to a unique and precise length so that the edge of the assembled document is flat except for the tabs and indexing features. The trimming operation is more important in folded booklets than in bound book type documents. 
     According to one embodiment, the controller  120 ,  320  employs an edge sensor, such as an optoelectronic sensor to sense an edge of a sheet. The sheet is moved precisely with respect to the sensed position of the edge to punch the sheet for formation of the features according to a schedule provided by the controller. 
     Although the invention has been described as employing a process of punching and trimming followed by folding, stacking, and binding, the order of the process steps may be varied as long as the formation of the features is performed on individual sheets prior to binding. 
     The systems used to load, align, register, and staple sheets in the binding system according to the present invention are those that are known to those in the field of desktop and commercial printers. 
     The invention may be used for making documents of any size. The term document as used herein is intended to mean documents of all sizes from small booklets of only a few sheets to large books with hundreds of pages. 
     The operation of a desktop booklet maker including the stacking, folding, stapling, and other operations is described in further detail in U.S. Pat. No. 6,099,225 and International Publication No. WO 00/18583 both of which are incorporated herein by reference in their entirety. 
     While the invention has been described in detail with reference to the preferred embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made and equivalents employed, without departing from the present invention.