Patent Publication Number: US-7590380-B2

Title: Bookbinding apparatus and bookbinding method

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a bookbinding apparatus and a bookbinding method. 
   2. Description of the Related Art 
   Bookbinding apparatuses for biding a book using a sheet bundle composed of a plurality of pages of sheets (paper) have been known. 
   In a bookbinding apparatus, sheet bundles, each composed of a plurality of pages of sheets, are once accumulated in an accumulating space so as to produce a bound book by pasting and stapling the sheet bundle. 
   Various bookbinding methods have been proposed. As an example, a casing-in bookbinding method is known, in which the center of a cover sheet with a size larger than that of the sheet bundle (A4 sheet bundle versus A3 cover sheet, for example (Japanese Industrial Standard)) is glued at an end of the sheet bundle so as to wrap the cover sheet around the sheet bundle (see Japanese Patent Laid-Open No. 2004-155152, for example). 
   In the bookbinding apparatus, during printing, an interrupting factor for interrupting the printing may occur. In this case, after the printing has been interrupted and the interrupting factor has been resolved, the printing process may be restarted. When the interrupting factor for interrupting the printing is generated, part of sheets already printed may be accumulated in the accumulating space. Upon restarting the printing process, it may be economically desirable to use the already printed sheets for bookbinding to reduce paper waste. However, if any defect (sheet damage and contaminated paper) is present in the already printed sheets caused by the printing interruption or other reasons, a defective bound book may be produced as a result of using the defected printed sheets. 
   SUMMARY OF THE INVENTION 
   An embodiment of the present invention has been made in view of the problems mentioned above, and it provides an improved bookbinding apparatus and bookbinding method. 
   According to an aspect of the present invention, an embodiment is directed to a bookbinding apparatus and bookbinding method capable of selecting the priority, when an interrupting factor for interrupting a printing job is generated, between the use of the already printed sheet bundle accumulated in the accumulating space during printing interruption and no use of the already printed sheet bundle. 
   As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate numerous embodiments, features and aspects of the invention and, together with the description, serve to explain the principles of the invention. 
       FIG. 1  is a drawing showing an exemplary configuration of a bookbinding system (bookbinding apparatus) according to an embodiment of the present invention. 
       FIG. 2  is a block diagram showing components of a printing apparatus  105  according to an embodiment of the present invention. 
       FIG. 3  is a sectional view of the printing apparatus  105  according to an embodiment of the present invention. 
       FIG. 4  is a drawing showing the configuration of an operation unit  204  included in the printing apparatus  105  according to an embodiment of the present invention. 
       FIGS. 5A to 5D  are drawings showing examples of operating screens displayed in the liquid crystal display shown in  FIG. 4  according to an embodiment of the present invention. 
       FIGS. 6A to 6C  are drawings showing examples of operating screens displayed in the liquid crystal display shown in  FIG. 4  according to an embodiment of the present invention. 
       FIGS. 7A to 7D  are drawings showing examples of operating screens displayed in the liquid crystal display shown in  FIG. 4  according to an embodiment of the present invention. 
       FIG. 8  is a drawing showing the configuration of a casing-in bookbinding apparatus according to an embodiment of the present invention. 
       FIG. 9  is a drawing showing a configuration of a computer terminal according to an embodiment of the present invention. 
       FIG. 10  is a drawing of a software configuration of a computer terminal according to an embodiment of the present invention. 
       FIG. 11  is a drawing of a display screen for setting printing conditions by a printer driver according to an embodiment of the present invention. 
       FIG. 12  is a drawing of a screen displayed when a property button is pushed down in a property setting screen of the printer driver according to an embodiment of the present invention. 
       FIG. 13  is a drawing of a screen displayed when a finish tab is selected in the property setting screen of the printer driver according to an embodiment of the present invention. 
       FIG. 14  is a flowchart of a bookbinding process according to an embodiment of the present invention. 
       FIG. 15  is a flowchart of the bookbinding process according to an embodiment of the present invention. 
       FIG. 16  is a flowchart showing a printing restart process when the printing is interrupted according to an embodiment of the present invention. 
       FIG. 17  is a table showing the printing interruption factors and treating methods for the factors according to an embodiment of the present invention. 
       FIG. 18  is a table showing the number of sheets stacked on an accumulation tray during the printing interrupting and treating methods for the number according to an embodiment of the present invention. 
       FIG. 19  is a table showing the number of sheets stacked on an accumulation tray during the printing interrupting and treating methods for the number according to an embodiment of the present invention. 
       FIG. 20  is a drawing showing a display screen for allowing a user to designate whether the sheets stacked on the accumulation tray are used or not according to an embodiment of the present invention. 
   

   DESCRIPTION OF THE EMBODIMENTS 
   The present invention will now be described in detail with reference to the drawings showing various embodiments thereof. In the drawings, elements and parts which are identical throughout the views are designated by identical reference numerals, and duplicate description thereof is omitted. 
   Embodiments of the present invention will be described below with reference to the drawings. 
   First Exemplary Embodiment 
   (Entire Configuration of Bookbinding System (Bookbinding Apparatus)) 
     FIG. 1  is a drawing of an exemplary configuration of a bookbinding system (bookbinding apparatus) according to an embodiment of the present invention. 
   Referring to  FIG. 1 , a printing apparatus  105  performs print processing on a sheet based on image data as well as conveys printed sheets to a stacker  104 . The stacker  104  places the printed sheets conveyed from the printing apparatus  105  on a stack tray (not shown). The stacker  104  can also convey the sheets conveyed from the printing apparatus  105  to a casing-in bookbinding apparatus  103  without placing them on the stack tray. The casing-in bookbinding apparatus  103  places a plurality of sheets S conveyed from the printing apparatus  105  via the stacker  104  on an accumulating tray  42 , which will be described later with reference to  FIG. 8 , as a sheet bundle S 1 . Then, the sheet bundle S 1  placed on the accumulating tray  42  is wrapped with a cover sheet S 2  placed on a cover sheet stack tray  70 , which will be described later with reference to  FIG. 8 , so as to produce a casing-in book. 
   The casing-in bookbinding apparatus  103  can also convey the sheet S conveyed from the stacker  104  to a saddle-stitched bookbinding apparatus  102  without placing it on the accumulating tray  42 . The saddle-stitched bookbinding apparatus  102  produces a saddle-stitched book by executing the saddle stitching on the sheet bundle S 1  composed of a plurality of the sheets S conveyed from the printing apparatus  105  via the casing-in bookbinding apparatus  103 . The saddle-stitched book produced in the saddle-stitched bookbinding apparatus  102  is conveyed to a paper cutter  101  for executing the cutting on the book. 
   In  FIG. 1 , the bookbinding system (bookbinding apparatus)  2000  includes the printing apparatus  105 , the stacker  104 , the casing-in bookbinding apparatus  103 , the saddle-stitched bookbinding apparatus  102 , and the paper cutter  101 ; alternatively, a different combination of devices may be employed. The bookbinding system (bookbinding apparatus)  2000  according to an embodiment can be constructed by combining at least the printing apparatus  105  with the casing-in bookbinding apparatus  103 . 
   (Control Configuration of Printing Apparatus) 
     FIG. 2  is a block diagram showing components of the printing apparatus  105  according to an embodiment of the present invention. 
   Referring to  FIG. 2 , a scanner unit  201  optically reads a plurality of manuscripts (images printed on a sheet such as paper) so as to produce image data as well as executes image processing, such as shading correction processing, on the read image data. Then, the scanner unit  201  stores the image data for a plurality of pages having the image processing executed thereon in a hard disk (HDD)  209  as one printing job. An external I/F  202  receives the printing job including the image data for a plurality of pages from the computer terminal  233  connected to the printing apparatus  105  via a network  232 . A printer unit  203  performs printing on a plurality of sheets based on the printing job stored in the hard disk  209 . Since the printing job is composed of image data of a plurality of pages, a plurality of the image data are printed on the plurality of the sheets, respectively. An operating unit  204  receives various instructions from an operator of the printing apparatus  105  so as to establish various settings on the printing apparatus  105  by transmitting the received instructions to a memory controller  206 . 
   A CPU  205  writes the program read from an ROM  207  on an RAM  208  so as to control the entire bookbinding system  2000  including the printing apparatus  105  by executing the program using the RAM  208 . In the ROM  207 , a program is stored for interpreting PDL (page description language) code data received by the external I/F  202  from an external device as a printing job. Furthermore, in the ROM  207 , a program is stored for producing data printable in the printer unit  203  after the PDL code data are interrupted. The memory controller  206  controls access to the ROM  207 , the RAM  208 , and the hard disk  209  from each element. 
   A compression-expansion unit  210  can execute compression processing on the image data stored in the RAM  208  and the hard disk  209  using various compression systems such as a JBIG (joint bi-level image experts group) and a JPEG (joint photographic experts group). The compression-expansion unit  210  can also execute to expand the image data compressed by the various compression systems. 
   A rotation unit  231  rotates image data when it is necessary upon executing the printing by transmitting the image data stored in the hard disk  209  to the printer unit  203 . The rotation unit  231  can rotates the image data at an arbitrary angle such as 180°, at which the image data are reversed in the vertical direction, and 90°. The rotation angle of the rotating processing executed by the rotation unit  231  can be established from the CPU  205 . 
   An option I/F  230  is an interface of the CPU  205  for communicating with the stacker  104 , the casing-in bookbinding apparatus  103 , the saddle-stitched bookbinding apparatus  102 , and the paper cutter  101 , which are optional apparatuses connected to the printing apparatus  105 . The respective stacker  104 , the casing-in bookbinding apparatus  103 , the saddle-stitched bookbinding apparatus  102 , and the paper cutter  101  have a CPU (not shown) for controlling its internal operation. Then, the CPU  205  of the printing apparatus  105  controls the stacker  104 , the casing-in bookbinding apparatus  103 , the saddle-stitched bookbinding apparatus  102 , and the paper cutter  101  by transmitting a control command for controlling the CPU of each optional apparatus via the option I/F  230 . 
   (Configuration of Printing Apparatus) 
   Next, with reference to  FIG. 3 , the configuration of the printing apparatus  105  according to an embodiment will be described. 
   The printing apparatus  105  generally includes the scanner unit  201  and the printer unit  203 . The scanner unit  201  feeds sheets stacked on a document feed unit  250  one by one sequentially in a stacking order from the top to a platen glass  211 . Then, the document feed unit  250  discharges the sheet on a discharge tray  219  after the reading operation by the scanner unit  201  is finished. When a document sheet is conveyed on the platen glass  211 , the scanner unit  201  lights a lamp  212  so as to start an optical unit  213  to move, so that the document sheet is scanned from the below while being radiated. The reflected light from the document is led to a CCD image sensor (referred to as a CCD below)  218  via a plurality of mirrors  214  to  216  and a lens  217 , so that scanned document images are read by the CCD  218  as image data. The image data read by the CCD  218  are stored in the hard disk  209  after a predetermined image processing is performed thereon. 
   The printer unit  203  outputs a laser beam corresponding to the image data read out of the hard disk  209  from a laser radiation unit  322  driven by a laser driver  321 . On a photosensitive drum  323  radiated with the laser beam, electrostatic latent images are formed in accordance with the laser beam. A developing unit  324  allows a developer (toner, for example) to adhere on the electrostatic latent images. 
   On the other hand, a sheet S is fed from any one of cassettes  311  to  314  and a manual feed tray  315  simultaneously with the irradiation initiation of the laser beam, and conveyed to a transfer unit  325  via a conveying path  331 . The manual feed tray  315  is provided with a sheet detection sensor  315   a  for detecting a sheet s placed thereon. The transfer unit  325  transfers the developer adhered on the photosensitive drum  323  onto the sheet S. The sheet S having the developer transferred thereon is conveyed by a conveying belt  326  to a fixing unit  327  for being heated in the fixing unit  327 . The developer on the sheet S is thereby fixed on the sheet S. The sheet S having the developer fixed thereon is conveyed to the stacker  104  via conveying paths  335  and  334 . Upon conveying the sheet S to the stacker  104 , when the sheet S is conveyed after the sheet S is inverted, the CPU  205  controls the printer unit  203  in leading the sheet S to conveying paths  336  and  338 . Thereafter, the sheet S is conveyed in the reverse direction to the stacker  104  via conveying paths  337  and  334 . 
   (Configuration of Casing-In Bookbinding Apparatus) 
   Next, with reference to  FIG. 8 , an exemplary configuration of the casing-in bookbinding apparatus  103  will be described. 
   The casing-in bookbinding apparatus  103  includes at least a conveying and aligning unit  21  for conveying and aligning the sheet S, an adhesive coating unit  22 , and a cutting unit  23 . The cutting unit  23  can cut the sheet bundle S 1  along three sides other than the bonded side. 
   The conveying and aligning unit  21  includes a first conveying path T 1  for conveying the sheet S conveyed via the stacker  104  and second and third conveying paths T 2  and T 3  branched from the first conveying path T 1 . The first conveying path T 1  is provided with conveying roller pairs  25 . On the downstream side of the conveying roller pair  25 , a switching flapper  27  is provided at a bifurcation point between the second conveying path T 2  and the third conveying path T 3  for switching the conveying path. 
   In such a conformation of the conveying paths, when the CPU  205  selects a normal discharge mode, the sheet S, which is conveyed into the casing-in bookbinding apparatus  103  from the printing apparatus  105  via the first conveying path T 1 , is led to the third conveying path T 3  by the switching flapper  27 . Then, the sheet S is conveyed to the saddle-stitched bookbinding apparatus  102  via a plurality of the conveying roller pairs  25  provided in the third conveying path T 3 . On the other hand, when the CPU  205  selects a casing-in bookbinding mode, the sheet S is lead to the second conveying path T 2  by the switching flapper  27 , and further conveyed onto the accumulating tray  42  forming the aligning area of the conveying and aligning unit  21 . The accumulating tray  42  includes a receiving unit  42   a  for receiving the sheet S. A predetermined number of the sheets S are placed in an inclined state on the receiving unit  42   a  so as to form one sheet bundle S 1 . 
   When a sheet bundle S 1  composed of a predetermined number of sheets is formed, the receiving unit  42   a  is downwardly moved by a predetermined distance toward a position P 1  (direction of arrow a), and then, it is positioned at a position P 2  by being moved in a direction perpendicular to the initial moving direction (direction of arrow b) (diagonally downward) by a predetermined distance. The receiving unit  42   a  is moved by a movement mechanism (not shown in detail). 
   At the position P 2 , there are provided grippers (conveying means)  55   a  and  55   b  for holding ends of the sheet bundle S 1  placed on the receiving unit  42   a . The grippers  55   a  and  55   b  direct the gripped sheet bundle S 1  in substantially the vertical direction (erect the sheet bundle S 1  in substantially the vertical direction). Then, while the substantial vertical direction being maintained (one side of the sheet bundle S 1 , at which an adhesive is to be applied as will be described later, is downward directed), the grippers  55   a  and  55   b  downward move the sheet bundle S 1  toward an adhesive applying unit  22 . 
   Then, the sheet bundle S 1  is substantially vertically positioned at a predetermined position on a coating region in the movement path of a bonding unit  66 . Then, the bonding unit  66 , which has been put at a standby position, is moved to a predetermined starting position of the coating region. Thereafter, in a state that a coating roller is normally rotated so as to come in contact with the edge side of the sheet bundle S 1 , the bonding unit  66  is moved relative to the sheet bundle S 1  from the starting position toward a predetermined turn back position. Thereby, an adhesive is uniformly applied at the edge side of the sheet bundle S 1  by the coating roller having the adhesive in a container  66   a  carried on its surface. 
   When the bonding unit  66  reaches the above-mentioned turn back position, the coating roller is stopped normally rotating while the bonding unit  66  is stopped moving. Thereafter, the bonding unit  66  starts moving from the predetermined turn back position toward the starting position in a state that the coating roller is reversely rotated for this time. At the time when the bonding unit  66  again reaches the starting position, the coating roller is stopped reverse rotating as well as the bonding unit  66  is stopped moving. When such a reciprocating movement is repeated twice, for example, the adhesive coating is completed. 
   Upon completion of applying the adhesive on the edge side of the sheet bundle S 1 , the bonding unit  66  is moved to the standby position or a replenishing position so as to secure the conveying path for the sheet bundle S 1 . Then, along the substantial vertical conveying path (in an intersecting direction with the movement direction of the bonding unit  66 ), the sheet bundle S 1  gripped by the grippers  55   a  and  55   b  is downward moved toward a cover sheet bonding unit  60 . 
   During applying the adhesive to the edge side of the sheet bundle S 1  in such a manner, a cover sheet S 2  has been already conveyed to the cover sheet bonding unit  60  from a cover-sheet accumulation tray  70  and placed on standby. The back side of a backbone region  1002  is positioned at a predetermined position of the cover sheet bonding unit  60  intersecting the substantial vertical conveying path of the sheet bundle S 1 . The edge side of the sheet bundle S 1  having the adhesive coated thereon is pushed onto the positioned cover sheet S 2  in the vertical direction from the above by the grippers  55   a  and  55   b . In this state, the sheet bundle S 1  is further moved in the downward vertical direction by the grippers  55   a  and  55   b  leaving its edge side being attached to the cover sheet S 2  due to the adhesive, so that the sheet bundle S 1  is pushed onto a slidable abutment plate located below the cover sheet bonding unit  60 . Then, the cover sheet S 2  and the sheet bundle S 1  are pressed from both sides in an abutted state to the abutment plate by slidable back-folding plates. Thereby, creases are formed on the cover sheet S 2  in accordance with the thickness of the sheet bundle S 1 . 
   Then, after the abutment plate slides outside so as to form a conveying path for the sheet bundle S 1 , the grippers  55   a  and  55   b  deliver the sheet bundle S 1  with the cover sheet S 2  bonded thereon over to the cutting unit  23  in the below. 
   Next, the cutting unit  23  will be described. 
   Reference numeral  120  denotes a cutting unit; numeral  121  a rotating table; numeral  122  a rotatable gripper for gripping the sheet bundle S 1  on the rotating table  121 . The cutting unit  120  includes a cutting blade  120   a , a movable presser bar for pressurizing the end of the sheet bundle S 1  during cutting, a fixed presser bar, and a presser bar movement mechanism for driving these bars. 
   When the sheet bundle S 1  with the cover sheet S 2  bonded thereon is delivered to the cutting unit  23  by the grippers  55   a  and  55   b , the sheet bundle S 1  is conveyed toward the cutting blade  120   a  in the vertical direction. When the sheet bundle S 1  is conveyed to the cutting blade  120   a , the gripper  122  is driven so that the sheet bundle S 1  is pinched between the gripper  122  and the rotating table  121 . 
   Then, the cutting blade  120   a  moves to a predetermined position for waiting to form a space necessary for the rotation and movement of the sheet bundle S 1  on the basis of the thickness information of the sheet bundle S 1 . Then, the cutting blade  120   a  cuts one edge side of the sheet bundle S 1 . 
   When the one edge side is cut, the presser bar and the cutting blade  120   a  move again to a predetermined position for waiting to form a space necessary for the rotation and movement of the sheet bundle S 1  on the basis of the thickness information of the sheet bundle S 1 . Then, the rotating table  121  and the gripper  122  are again driven so that the sheet bundle S 1  clamped between the rotating table  121  and the gripper  122  is rotated (by an angle of 18 0 °) and moved to a position capable of cutting an edge side to be cut by the cutting blade  120   a . Then, the cutting blade  120   a  cuts one edge side of the sheet bundle S 1 . By the same operation, the third edge side of the sheet bundle S 1  is cut. 
   Upon completion of cutting the three edge sides in such a manner, the rotating table  121  is returned to an original position, and the sheet bundle S 1  clamped between the rotating table  121  and the gripper  122  is conveyed to an accommodation unit  34  via a discharge roller  123 . In this case, the sheet bundle S 1  discharged by the discharge roller  123  is compressed into the accommodation unit  34 , and is accommodated in a substantially vertically erected state while downwardly directing the edge side having the adhesive coated thereon. In the description below, the sheet bundle S 1  with the cover sheet S 2  bonded thereto is referred to as a bound book S 3 . 
   (Configuration of Operation Unit) 
   Next, with reference to  FIG. 4 , the operation unit  204  included in the printing apparatus  105  will be described. 
   The operation unit  204  includes a hard key group  4 - 240  having various hard keys  4 - 241  to  4 - 246 . The operation unit  204  also includes a dot-matrix liquid crystal display  4 - 250  made of a liquid crystal display device. The liquid crystal display  4 - 250  includes a touch panel formed in the front. When an operator of the printing apparatus  105  pushes the key display, the operation unit  204  detects the key entry so as to send a signal corresponding to the key entry to the CPU  205 . The CPU  205  executes the operation in accordance with the received signal by controlling the printing apparatus  105  on the basis of the program stored in the ROM  207 . 
   The key  4 - 243  is a power supply key for turning on/off the power supply; the key  4 - 244  an energy saving key for turning on/off a safe mode; the start key  4 - 241  a key for allowing an operator to instruct the scanner unit  201  to start various processes such as reading images on a document; and a stop key  4 - 242  a key for allowing an operator to instruct the bookbinding system  2000  including the printing apparatus  105  to stop the operation being executed. 
   The key group  4 - 245  includes ten keys 0 to 9 for the entry of the number of copies, the zoom magnification, and so forth; and a clear key for clearing the entry. The number of copies inputted with the key group  4 - 245  is displayed on the liquid crystal display  4 - 253 . The reset key  4 - 246  is a key for returning the setting conditions, which are set by an operation via the liquid crystal display  4 - 250  and the hard key group  4 - 240 , to an original state. 
   The liquid crystal display  4 - 250  displays operation states of the bookbinding system  2000  by the instruction from the CPU  205 . On the liquid crystal display  4 - 250 , touch keys are also displayed. In the liquid crystal display  4 - 250 , the key  4 - 252  is for selecting a cassette having the sheet S placed thereon for use in printing by the printing apparatus  105 . When the key  4 - 252  is pushed by an operator, the CPU  205  controls the operation unit  204  in displaying a sheet selection screen shown  FIG. 5A  on the liquid crystal display  4 - 250 . 
   With a key group  4 - 271  of the sheet selection screen shown in  FIG. 5A , any one of the cassettes  311  to  315  is selected for use in printing. When a close key  4 - 270  is pushed by an operator, the CPU  205  closes this display screen so as to return it to the display screen of  FIG. 4  for displaying the selected cassette on the display  4 - 251 . 
   Keys  4 - 258  and  4 - 262  shown in  FIG. 4  are for adjusting the density. The CPU  205  makes the density to be adjusted by these keys display on a display  4 - 263 . A key  4 - 259  is for turning on/off the automatic density adjusting function; a key  4 - 261  is for setting a mode such as a picture mode and a text mode. 
   Keys  4 - 254  and  4 - 255  are for setting the direct and the contraction/expansion, respectively. When the key  4 - 255  is pushed down, the CPU  205  allows the liquid crystal display  4 - 250  to display a magnification display screen shown in  FIG. 5B , enabling the magnification to be set in detail. When the magnification is selected with a key group  4 - 273  of the magnification display screen shown in  FIG. 5B  and a close key  4 - 272  is pushed down by an operator, the CPU  205  closes this display screen so as to return it to the display screen of  FIG. 4  for displaying the set magnification on the display  4 - 264 . 
   A key  4 - 257  is a double sided key, and when the key  4 - 257  is pushed down, the CPU  205  allows the liquid crystal display  4 - 250  to display a double-sided printing setting screen shown in  FIG. 5C . The setting the double-sided printing will be described below with reference to  FIG. 5C . 
   Referring to  FIG. 5C , a key  4 - 280  is for setting the double-sided printing on a sheet using a document having images printed only on one side (referred to as an one-sided document below); a key  4 - 281  is for setting the double-sided printing on a sheet using a document having images printed on both sides (referred to as a double-sided document below); a key  4 - 283  is for setting the one-sided printing on a sheet using a double-sided document; and a key  4 - 284  is for setting the page series double-sided printing. 
   A key  4 - 285  is for making effective the setting set by an operator in the double-sided printing setting screen shown in  FIG. 5C . When this key is pushed down, the CPU  205  makes effective the setting in the double-sided printing setting screen shown in  FIG. 5C  so as to return the liquid crystal display  4 - 250  to the screen of  FIG. 4 . A key  4 - 282  is for canceling the setting set in  FIG. 5C , and when this key is pushed down, the CPU  205  cancels the setting in the double-sided printing setting screen shown in  FIG. 5C  so as to return the liquid crystal display  4 - 250  to the screen of  FIG. 4 . 
   A key  4 - 286  is for enabling a user to set the detail. When the key  4 - 286  is pushed down by the user, the CPU  205  allows the liquid crystal display  4 - 250  to display the screen shown in  FIG. 5D . The detailed setting of the double-sided printing will be described below with reference to  FIG. 5D . 
   Referring to  FIG. 5D , a key  4 - 290  is a setting key for making the sheet S printed by the printing apparatus  105  lateral serial pictures; a key  4 - 291  is a setting key for making the sheet S vertical serial pictures. When with the key  4 - 290  or  4 - 291 , the kind of the double-sided printing is selected and a close key  4 - 292  is pushed down, the CPU  205  closes this display screen and returns the liquid crystal display  4 - 250  to the screen of  FIG. 5C . 
   As shown above, with the double-sided printing setting screen shown in  FIG. 5C  and the double-sided printing detailed setting screen shown in  FIG. 5D , the double-sided printing is enabled. 
   A key  4 - 256  on the displayed screen of  FIG. 4  is a sorter key for allowing a user to instruct the display of the operation unit  204  to display the setting screen for instructing a sheet processing apparatus  230  to execute the sheet processing by the user. 
   When the key  4 - 256  is pushed down by an operator, the CPU  205  shifts the liquid crystal display  4 - 250  of the operation unit  204  to a screen shown in  FIG. 6C , which will be described later. Then, the CPU  205  brings up candidates (casing-in binding and saddle-stitching binding) of the sheet processes executable by the sheet processing apparatus  230  to the operator. 
   The CPU  205  receives the instruction to execute desired sheet processing from an operator via the sheet processing setting screen shown in  FIG. 6C . Then, the CPU  205  controls the bookbinding system  2000  in executing the bookbinding processing selected by the operator via the sheet processing setting screen. 
   The procedure of the bookbinding setting will be described below with reference to  FIGS. 6A to 6C . 
   Methods for inputting image data for a plurality of pages used in printing the sheet S include a method inputting the image data from the scanner unit  201  (referred to as a first input method) and a method inputting the image data from the computer terminal  233  (referred to as a second input method). Then, in the description below, the two inputting methods will be described, respectively. 
   (Procedure of Bookbinding Setting—First Inputting Method) 
     FIGS. 6A to 6C  are drawings of examples of an operation screen displayed on the liquid crystal display  4 - 250  of the operation unit  204  shown in  FIG. 4 . 
     FIG. 6A  shows an application mode screen displayed on the liquid crystal display  4 - 250  by the CPU  205  in accordance with the pushing by an operator of the key  4 - 260  on the operation screen shown in  FIG. 4 . 
   The key  601  on the screen of  FIG. 6A  is for setting a bookbinding mode (casing-in bookbinding or saddle-stitched bookbinding). When the key  601  is pushed down by an operator, the CPU  205  allows the liquid crystal display  4 - 250  to display the document size selection screen shown in  FIG. 6B . 
     FIG. 6B  is an operation screen for designating the document size used in printing the sheet S to be a regular text of the bound book S 3  bound in a bookbinding mode. A key group  602  on the screen of  FIG. 6B  includes designating keys for allowing an operator to set the size of the document sheet to be a regular text. For example, when “A4 size” on the screen of  FIG. 6B  is pushed down and then, “next” is pushed down, the CPU  205  allows the liquid crystal display  4 - 250  to display the operation screen shown in  FIG. 6C . 
     FIG. 6C  is an operation screen for setting the kind of the bookbinding. By pushing down a casing-in bookbinding key  603  on the screen of  FIG. 6C , an operator can designate the casing-in bookbinding. On the other hand, by pushing down a saddle-stitched bookbinding key  604  on the screen of  FIG. 6C , the operator can designate the saddle-stitched bookbinding. When the operator designates the casing-in bookbinding by pushing down the casing-in bookbinding key  603 , the CPU  205  allows the liquid crystal display  4 - 250  to display the screen shown in  FIG. 7A . 
     FIG. 7A  is a screen for designating the bound book S 3  formed as whether left opening or right opening. When a left opening key  701  is pushed down and then, a key  703  is pushed, the CPU  205  designates a left opening bookbinding mode. On the other hand, when a right opening key  702  is pushed down and then, the key  703  is pushed, the CPU  205  designates a right opening bookbinding mode. Then, by the pushing down the key  703 , the CPU  205  allows the liquid crystal display  4 - 250  to display the screen shown in  FIG. 7B . 
     FIG. 7B  is a screen for designating the size of the cover sheet S 2  used as a cover sheet for forming the bound book S 3  and the feed source of the cover sheet S 2 . According to the embodiment, since the cover sheet S 2  is placed on the cover sheet stack tray  70 , after a sheet selection key  704  is pushed, with the screen (not shown) displayed on the liquid crystal display  4 - 250 , the cover sheet stack tray  70  is to be designated.  FIG. 7B  is a screen for designating the size of the sheet S used for a regular text for forming the bound book S 3  and also for the feed source of the sheet S. When the sheet selection key  704  is pushed down, the CPU  205  allows the liquid crystal display  4 - 250  to display the screen shown in  FIG. 5A  and makes the operator designate to feed the sheet S from any one of the cassettes  311  to  315 . When the key  706  pushed down after the cover sheet S 2  and the sheet S are selected via the sheet selection keys  704  and  705 , the CPU  205  establishes the setting about the cover sheet S 2  and the sheet S. Then, the CPU  205  allows the liquid crystal display  4 - 250  to display the screen shown in  FIG. 7C . 
     FIG. 7C  is a screen for setting the reading of the document sheet, by the scanner unit  201 , used in printing the sheet bundle S 1  to be a regular text of the bound book S 3 . A key  707  is for setting the size of the document sheet used in printing the sheet bundle S 1 . When the key  707  is pushed down, the CPU  205  allows the screen of  FIG. 6B  to be displayed and an operator to designate the size of the document sheet. When the operator designates the size of the document size, the CPU  205  fixes the document size. A key  708  is for designating that the document used in printing the sheet bundle S 1  is the double-sided printed document sheet. When the operator pushes the key  708  down, the scanner unit  201  reads the both sides of the document as image data so as to obtain the image data for two pages from one document sheet. Then, after a key  709  is pushed down, the CPU  205  allows the liquid crystal display  4 - 250  to display the screen shown in  FIG. 7D . 
     FIG. 7D  is a screen for setting that whether the sheet bundle S 1  to be a regular text of the bound book S 3  is double-sidedly printed using a re-feed sheet conveying path  332  or not. When a key  710  is pushed down, the CPU  205  allows the printer unit  203  to print only one side of the sheet S. On the other hand, when a key  711  is pushed down, the CPU  205  allows the printer unit  203  to print both sides of the sheet S. When a key  712  is pushed down, the CPU  205  determines the completion of the setting about the casing-in bookbinding so as to allow the liquid crystal display  4 - 250  to display the screen of  FIG. 6A . 
   (Procedure of Bookbinding Setting—Second Inputting Method) 
   Then, a second inputting method will be described. 
   The second inputting method uses image data inputted from the computer terminal  233  as image data for a plurality of pages used in printing the sheets S. 
     FIG. 9  is a drawing of an exemplary configuration of the computer terminal  233 . 
   Referring to  FIG. 9 , the computer terminal  233  includes a CPU  901  executing processing of mixed documents including graphic forms, images, and tables (including spreadsheet tables) on the basis of a document processing program stored in a programming ROM of a ROM  903  or an external memory  911 . The CPU  901  controls each bus device connected to a system bus  904  correctively. In the programming ROM of the ROM  903  or the external memory  911 , an operating system program (referred to as an OS below), which is a control program of the CPU  901 , and a printer driver (mentioned below) are stored. In a font ROM of the ROM  903  or the external memory  911 , font data used during the document processing are stored. In a data ROM of the ROM  903  or the external memory  911 , various data used during the document processing are stored. An RAM  902  functions as a main memory and a work area of the CPU  901 . 
   A keyboard controller (KBC)  905  controls the key entry from a key board  909  or a pointing device (not shown). A CRT controller (CRTC)  906  controls the displaying of a CRT display (CRT)  910 . A disk controller (DKC)  907  controls the access to the external memory  911  such as a hard disk (HD) and a floppy™ disk (FD). In the external memory  911 , a boot program, various applications, a printer-control command producing program (referred to as a printer driver below) are stored. A printer controller (PRTC)  908  is connected to the printing apparatus  105  via the network  232  so as to control the communication with the printing apparatus  105 . 
     FIG. 10  is a software configuration diagram of the computer terminal  233 . An application  1001 , a graphic engine  1002 , a printer driver  1003 , and a system spooler  1004  exist as software programs stored in the external memory  911 . 
   The application  1001  stored in the external memory  911  is loaded in the RAM  902  for execution. When the printing job is transmitted to the printing apparatus  105  from the application  1001 , the printing (outputting) is performed using the graphic engine  1002  that is executably loaded into the RAM  902 . 
   The data outputted from the graphic engine  1002  is transmitted to the printer driver  1003 . The printer driver  1003  is loaded into an RAM  902  from the external memory  911  and executed by the CPU  901 . Then, the printer driver  1003  converts the data transmitted from the graphic engine  1002  into a control command which can be interpreted by the printing apparatus  105  (a PDL command, for example). The control command is to be outputted to the printing apparatus  105  via the system spooler  1004  loaded into the RAM  902  and the network  232 . This control command will be referred to as a printing job. 
   In order to produce the printing job by the printer driver  1003 , printing processing conditions in the printing apparatus  105  (the kind of the sheet for printing and the double-sided or one-sided printing, etc.) have to be established. These are set from a window generally provided by the printer driver  1003  (the menu displayed on the CRT  910 ). Then, the printer driver  1003  adds the contents set by an operator of the computer terminal  233  to the printing job via the window as the printing processing conditions. 
     FIG. 11  is a drawing of a window for setting the printing processing conditions by the printer driver  1003  installed into the computer terminal  233 . 
   During producing document by the application  1001 , the computer terminal  233  allows the CRT  910  to display the setting screen of  FIG. 11  by activating the printer driver  1003 . 
   Referring to the setting screen of  FIG. 11 , an operator (worker) of the computer terminal  233  operates a printer-name selection box  1101  using a pointing device (not shown). By this operation, the printing apparatus  105  or another printing apparatus is selected as a target of the printing job transmitted by the computer terminal  233 . In  FIG. 11 , the computer terminal  233  selects the printing apparatus  105 . The operator of the computer terminal  233  also operates a printing-range selection box  1102  using the pointing device. Thereby, a desired page among documents produced by the application  1001  is determined as a printing range to be printed by the printing apparatus  105 . When the operator selects “all”, the printer driver  1003  is to print the entire documents produced by the application  1001 . When the operator selects “present page”, the printer driver  1003  is to print the page presently displayed on the CRT  910  among a plurality of document pages produced by the application  1001 . When the operator selects “designated pages”, the printer driver  1003  is to print the pages inputted in an edit box  1103  among a plurality of document pages produced by the application  1001 . Also, the printer driver  1003  is to print the number of copies inputted in a printing-copy number setting box  1104  by the operator. 
   Then, when completing the setting of printing processing conditions of the printing job to be transmitted to the printing apparatus  105 , the operator of the computer terminal  233  pushes an OK button  1106  down. Thereby, the printer driver  1003  starts producing the printing job. In addition, when stopping the producing the printing job, the operator of the computer terminal  233  pushes a cancel button  1107  down. 
     FIG. 12  is a drawing of a screen displayed when a property button  1105  is pushed down in a printer-driver property setting screen of  FIG. 11 . In addition,  FIG. 12  illustrates a screen displayed when a page setting tab is selected. 
   The operator of the computer terminal  233  operates a document-size selection box  1201  using the pointing device (not shown). By this operation, the printer driver  1003  selects the document size of each page of the document complied by the application  1001 . The size of the document complied by the application  1001  has been generally designated so that this size is automatically selected (A4, in  FIG. 12 ). When the operator selects “same as document size” in an output sheet-size selection box  1202 , the printer driver  1003  selects “A4 size” as a sheet size used in printing (outputting) by the printing apparatus  105 . In addition, the operator can also select a desired sheet size, such as “A3 size” and “B5 size”, other than “same as document size”. In this case, however, the size different from the document size is selected, so that the printer driver  1003  produces the printing job after changing the magnification. Also, the printer driver  1003  sets the number of copies in the printing job in accordance with that inputted by the operator in a copy number selection box  1203 . The printer driver  1003  inputs the printing direction selected by the operator in a printing direction designation box  1204 . 
   When an OK button  1205  is selected by the operator, the selections inputted in the document-size selection box  1201 , the output sheet-size selection box  1202 , the copy number selection box  1203 , and the printing direction designation box  1204  are confirmed. On the other hand, when the operator selects a cancel button  1206 , the selections inputted in the boxes  1201  to  1204  are not confirmed and returned to initial settings established in advance. 
     FIG. 13  is a screen displayed when a finishing tab  1208  is selected in a property setting screen of the printer driver  1003  shown in  FIG. 12 . 
   The operator of the computer terminal  233  operates a printing method selection box  1301  using the pointing device (not shown). By this operation, the printer driver  1003  selects the printing method (one of the printing processing conditions) when the printing job is executed in the printing apparatus  105 . The printing method includes “one-sided printing” printing only one side of the sheet and “double-sided printing” printing both sides of the sheet. 
   The operator of the computer terminal  233  also operates a sheet processing selection box  1304  using the pointing device (not shown). By this operation, the printer driver  1003  selects the kind of the sheet processing to be performed on the sheet which has been printed in the printing apparatus  105 . The kind of the sheet processing includes staple processing, cutting, saddle-stitched binding, and casing-in binding. The stapling is the processing executed by the saddle-stitched bookbinding apparatus  102 , and the stapling is performed on edges of a plurality of the sheets which have been printed in the printing apparatus  105 . The saddle stitching is processing executed by the saddle-stitched bookbinding apparatus  102 , and the stapling is performed on the center portions of a plurality of the sheets which have been printed in the printing apparatus  105  as well as the sheets are folded at the center portions. The cutting is processing executed by the paper cutter  101 , and the cutting is performed on end portions of a plurality of the sheets which have been printed in the printing apparatus  105 . The casing-in binding is processing executed by the casing-in bookbinding apparatus  103 , and a plurality of the sheets S which have been printed in the printing apparatus  105  are wrapped around the cover sheet and bonded thereto so as to obtain the bound book. 
   The operator of the computer terminal  233  also operates a box  1305  using the pointing device (not shown). By this operation, when the interruption is generated in the printing job of the casing-in binding designated as the sheet processing, the printer driver  1003  selects the way how to re-start the processing. The re-starting method of the printing processing includes a method using sheets already accommodated on the accumulating tray  42  and a method without using the accommodated sheets. When the former method is selected, the economy due to use of the already printed sheets takes the precedence. On the other hand, if the latter method is selected, the removal of defective bound books due to no use of the already printed sheets takes the priority. 
   Then, when the operator selects an OK button  1302 , the selections inputted in the printing method selection box  1301  and the sheet processing selection box  1304  are confirmed. On the other hand, if the operator selects a cancel button  1303 , the selections inputted in the printing method selection box  1301  and the sheet processing selection box  1304  are not confirmed and returned to initial settings established in advance. 
   (Executing Procedure of Bookbinding—One-Sided Printing) 
   Next, the flow of the bookbinding according to the first embodiment will be described with reference to  FIG. 14 . Each step in the flowchart of  FIG. 14  is executed by the CPU  205  that reads out the program stored in the hard disk  209  to the RAM  208 . The casing-in binding executed by pushing the casing-in bookbinding key  603  on the screen of  FIG. 6C  is described hereinafter.  FIG. 14  shows the operations when the printing only one side of the sheet S is set in  FIG. 7D . 
   At Step S 1401 , the CPU  205  executes the inputting image data for a plurality of pages. The inputting processing may employ any one of the above-mentioned two methods. When the first method, which inputs image data from the scanner unit  201 , is employed, when a start key  4 - 241  is pushed down, the image data for a plurality of pages are inputted by reading images on documents placed on the document feed unit  250  so as to output them to the printer unit  203 . On the other hand, when the second method using the printing job (image data) received from the computer terminal  233  is employed, the external I/F  202  reads out the image data included in the printing job as a control code by receiving the printing job. Then, the memory controller  206  outputs the read out printing job to the printer unit  203  so that the image data for a plurality of pages are inputted. 
   At Step S 1402 , the CPU  205  determines that the binding mode set by the operator in  FIG. 7C  is whether the opening right binding mode or the opening left binding mode. If it is the opening left binding mode, the process proceeds to Step S 1403 , and if it is the opening right binding mode, the process proceeds to Step S 1414 . 
   Steps S 1403  to S 1407  are printing processes in that the printing job composed of the image data for M pages is performed on a first page, a second, . . . an M−1 th , and an M th  page. Whereas, Steps S 1414  to S 1417  are printing processes in that the printing is performed on an M th  page, an M−1 th , . . . a second, and a first page in the order reverse to the Steps S 1403  to S 1407 . 
   At Step S 1403 , the CPU  205  sets the initial value “1” as a page identification information N for controlling the printing order of the image data for a plurality of pages. The page identification information N is stored in the RAM  208  and is the information readable and writable by the CPU  205 . 
   At Step S 1404 , the CPU  205  allows the printer unit  203  to execute the printing on an N th  page, and the sheet S is conveyed to the stacker  104  after the sheet S is inverted at Step S 1405 . The reason for the inversion is that the sheet S with its printed top surface (face up state) is accumulated on the accumulating tray  42  in a state downwardly directing the printed surface (face down state). Then, the CPU  205  allows a conveying unit (not shown) within the stacker  104  to convey the sheet S to the casing-in bookbinding apparatus  103 . Also, the CPU  205  allows the casing-in bookbinding apparatus  103  to convey the sheet S conveyed from the stacker  104  to the accumulating tray  42 . 
   At Step S 1406 , the CPU  205  adds “1” to the page identification information N and the process proceeds to Step S 1407 . At Step S 1407 , the CPU  205  determines whether the page identification information N becomes M+1, and if N=M+1, the process proceeds to Step S 1408 ; if not, the process returns to Step S 1404 . The M herein is the number of pages of the printing job, and if the printing job is the image data for 10 pages, for example, “10” is established. In the above-mentioned second method, since the printing job is stored in the hard disk  209  in advance so that the number of pages is determined, this page number is set as M. On the other hand, in the first method, the number of pages is not determined in advance. Then, at Step S 1407 , the CPU  205  determines the presence of the document to be sequentially read out by detecting it with a document detecting sensor (not shown) provided in the scanner unit  201 . Specifically, if the CPU  205  determines the absence of the document to be sequentially read out, the process proceeds to Step S 1408 ; if not, the process returns to Step S 1404 . 
   The CPU  205  forms the sheet bundle S by repeating the Steps S 1404  to S 1407  so as to accumulate a plurality of sheets S on the accumulating tray  42 . 
   Steps to be executed when the CPU  205  determines the mode to be the right opening bookbinding mode will now be described. 
   At Step S 1414 , the CPU  205  sets the initial value “1” as the page identification information N for controlling the printing order of the image data for a plurality of pages. 
   At Step S 1415 , the CPU  205  allows the printer unit  203  to execute the printing on an (M−N+1) th  page. The reason for the (M−N+1) th  page is that when the printing job of M pages is performed, the printing starts from the M th  page, which is the last page. In the right opening bookbinding mode, the sheet S is not inverted differently from the left opening bookbinding mode. This is because the printed sheets S are accumulated on the accumulating tray  42  in the face-up state (the state upwardly directing the printed surface). The CPU  205  herein allows the conveying unit (not shown) within the stacker  104  to convey the sheet S to the casing-in bookbinding apparatus  103 . Also, the CPU  205  allows the casing-in bookbinding apparatus  103  to convey the sheet S conveyed from the stacker  104  to the accumulating tray  42 . 
   At Step S 1416 , the CPU  205  increases the page identification information N and the process proceeds to Step S 1417 . At Step S 1417 , the CPU  205  determines whether the page identification information N becomes (M+1), and if N=M+1, the process proceeds to Step S 1408 ; if not, the process returns to Step S 1415 . In the first method, as mentioned above, the number of documents read by the scanner unit  201  is not determined until the entire documents are read out. Then, at Step S 1417 , the CPU  205  determines the presence of the document to be sequentially read out by detecting it with the document detecting sensor (not shown). Specifically, if the CPU  205  determines the absence of the document to be sequentially read out, the process proceeds to Step S 1408 ; if not, the process returns to Step S 1415 . 
   The CPU  205  forms the sheet bundle S 1  by repeating the Steps S 1415  to S 1417  so as to accumulate a plurality of sheets S on the accumulating tray  42 . 
   The bookbinding using the sheet bundles S 1  formed on the accumulating tray  42  by repeating the Steps S 1404  to S 1407  and the Steps S 1414  to S 1417  will be described below. The specific operations using the casing-in bookbinding apparatus  103  are the same as those described with reference to  FIG. 8 . 
   The CPU  205  aligns the sheet bundle S at Steps S 1408 , and aligns the sheet bundle S with the cover sheet S 2  at Steps S 1409  by applying an adhesive on an end of the sheet bundle S 1 . On the other hand, the CPU  205  feeds the cover sheet S 2  stacked on the cover sheet accumulating tray. In  FIG. 14 , the cover sheet S 2  is fed (S 1410 ) after the adhesive is applied (S 1409 ); alternatively, the cover sheet S 2  may be fed before the adhesive application. 
   The CPU  205  executes the bookbinding by bonding one end of the sheet bundle S 1  on the back portion of the cover sheet S 2  (back portion of the backbone region  1002 ) at Steps S 1411 . Then, the CPU  205  performs cutting on the sheet bundle S 1  having the cover sheet S 2  bonded thereto at Steps S 1412  and accumulates the sheet bundle S 1  on the accommodation unit  34  at Steps S 1413 . 
   (Executing Procedure of Bookbinding—Double-Sided Printing) 
   The process of the bookbinding according to the first embodiment will now be described with reference to  FIG. 15 . The casing-in bookbinding will be described hereinafter which is executed when the casing-in bookbinding key  603  on the screen of  FIG. 6C  is pushed.  FIG. 15  shows the operations when the double-sided printing of the sheet S is set in  FIG. 7D . 
   Since the Steps S 1501  and S 1502  of  FIG. 15  are the same as the Steps S 1401  and S 1402  of  FIG. 14 , the description is omitted. Also, the Steps S 1510  to S 1515  of  FIG. 15  are the same as the Steps S 1408  to S 1413  of  FIG. 14 , so that the description is omitted. 
   The Steps S 1503  to S 1509  below are the process of printing the printing job of image data for M pages from a first page, . . . to the M th  page. Whereas, the Steps S 1515  to S 1521  are the process printing the job from the M th  page, . . . to the first page in the order reverse to that of the Steps S 1503  to S 1509 . Since the sheet S is double-sided printed in  FIG. 15 , the process is different from that printing the job in the order of from a first page, a second page, a third page . . . . 
   At Step S 1503 , the CPU  205  sets the initial value “1” as the page identification information N. 
   At Step S 1504 , the CPU  205  determines whether the page identification information N is M or less, and if N≦M, the process proceeds to Step S 1505 ; if not, the process proceeds to Step S 1506 . 
   At Step S 1505 , the CPU  205  allows the cassette selected by pushing down the key  705  of  FIG. 7B  to feed the sheet S so as to print the images of the N th  page on the sheet. 
   At Step S 1506 , the CPU  205  determines whether “N−3” is larger than “0”, if it is larger, the process proceeds to Step S 1507 ; if not, the process proceeds to Step S 1508 . At Step S 1507 , the CPU  205  executes printing (N−3) th  page images on the sheet S conveyed from the re-feed sheet conveying path  332 . Numeral “3” herein designates the number of sheets retainable in the printing apparatus  105 . Upon double-sided printing, the printing apparatus  105  executes printing on three sheets continuously fed from the cassette. Thereafter, the printing apparatus  105  alternately repeats the printing images on the sheet S fed from the re-feed sheet conveying path  332  and the printing odd pages images on the sheet S fed from the cassette. By the repeated printing, both sides of the sheet S are printed. 
   At Step S 1508 , the CPU  205  adds “2” to “N” and the process proceeds to Step S 1509 . At Step S 1509 , the CPU  205  determines whether the page identification information N becomes M+5, and if N=M+5, the process proceeds to Step S 1510 ; if not, the process returns to Step S 1504 . 
   The printing order in the printing, which the CPU  205  allows the printer unit  203  to execute, will be described by assuming that the printing job is composed of image data for 10 pages and the cassette  311  is selected in  FIG. 7B . 
   First, the CPU  205  allows the cassette  311  to feed three sheets S, and first page images, third page images, and fifth page images are printed on the three sheets, respectively. The CPU  205  also conveys the three sheets, respectively having the first page images, third page images, and fifth page images printed thereon, to the re-feed sheet conveying path  332 . The sheets S conveyed from the re-feed sheet conveying path  332  are conveyed to the transfer unit  325  with the downward directed printed surface. 
   Then, the sheet S having the first page images printed thereon is conveyed to the transfer unit  325  by the CPU  205 , and the second page images are printed on the opposite side. Thereafter, the sheet S having both the first page images and second page images printed thereon is conveyed to the stacker  104  by the CPU  205 . Continuously, the seventh page images are printed on the sheet S fed from the cassette  311  by the CPU  205 . Then, the sheet S having the third page images printed thereon is conveyed to the transfer unit  325  by the CPU  205 , so that the fourth page images are printed on the opposite side. Then, the ninth page images are printed on the sheet S fed from the cassette  311  by the CPU  205 . Subsequently, the CPU  205  continuously conveys the sheets, respectively having the fifth page images, seventh page images, and ninth page images printed thereon, to the transfer unit  325  from the re-feed sheet conveying path  332 , so that the sixth page images, eighth page images, and tenth page images are printed on these sheets, respectively. 
   As described above, the printing order of image data for a plurality of pages is a page order of 1-3-5-2-7-4-9-6-8-10. 
   The process executed when the CPU  205  determines the mode to be the right opening bookbinding mode at Step S 1502  will be described. 
   At Step S 1516 , the CPU  205  sets the initial value “1” as the page identification information N. 
   At Step S 1517 , the CPU  205  determines whether the page identification information N is M or less, and if N≦M, the process proceeds to Step S 1518 ; if not, the process proceeds to Step S 1519 . 
   At Step S 1518 , the CPU  205  allows the cassette selected by pushing down the key  705  of  FIG. 7B  to feed the sheet S so as to print the images of the (M−N+1) th  page on the sheet. 
   At Step S 1519 , the CPU  205  determines whether “N−3” is larger than “0”, if it is larger, the process proceeds to Step S 1520 ; if not, the process proceeds to Step S 1521 . At Step S 1520 , the CPU  205  executes printing (M−N+4) th  page images on the sheet S conveyed from the re-feed sheet conveying path  332 . Thereafter, the printing apparatus  105  alternately repeats the printing images on the sheet S fed from the re-feed sheet conveying path  332  and the printing images on the sheet S fed from the cassette. By the repeated printing, both sides of the sheet S are printed. 
   At Step S 1521 , the CPU  205  adds “2” to N and the process proceeds to Step S 1522 . At Step S 1522 , the CPU  205  determines whether the page identification information N becomes (M+5), and if N=M+5, the process proceeds to Step S 1510 ; if not, the process returns to Step S 1517 . 
   The printing order in the printing, which the CPU  205  allows the printer unit  203  to execute, will be described by assuming that the printing job is composed of image data for 10 pages and the cassette  311  is selected in  FIG. 7B . 
   First, the CPU  205  allows the cassette  311  to feed three sheets S, and tenth page images, eighth page images, and sixth page images are printed on the three sheets, respectively. The CPU  205  also conveys the three sheets, respectively having the tenth page images, the eighth page images, and the sixth page images printed thereon, to the re-feed sheet conveying path  332 . 
   Then, the sheet S having the tenth page images printed thereon is conveyed to the transfer unit  325  by the CPU  205 , and the ninth page images are printed on the opposite side. Thereafter, the sheet S having both the tenth page images and the ninth page images printed thereon is conveyed to the stacker  104  by the CPU  205 . Continuously, the fourth page images are printed on the sheet S fed from the cassette  311  by the CPU  205 . Then, the sheet S having the eighth page images printed thereon is conveyed to the transfer unit  325  by the CPU  205 , so that the seventh page images are printed on the opposite side. Then, the second page images are printed on the sheet S fed from the cassette  311  by the CPU  205 . Subsequently, the CPU  205  continuously conveys the sheets, respectively having the sixth page images, fourth page images, and second page images printed thereon, to the transfer unit  325  from the re-feed sheet conveying path  332 , so that the fifth page images, third page images, and first page images are printed on these sheets, respectively. 
   As described above, the printing order of image data for a plurality of pages is 10-8-6-9-4-7-2-5-3-1, which is a page order reverse to that of the left opening bookbinding. 
   (Restart Printing During Interruption) 
   The restart printing when the printing is interrupted will now be described. 
     FIG. 16  is a flowchart of the restart printing process when the printing is interrupted. 
   Each step in the flowchart of  FIG. 16  is executed by the CPU  205  of the printing apparatus  105  that reads out the program stored in the hard disk  209  to the RAM  208 . Each step in the flowchart of  FIG. 16  is also executed in parallel with those of  FIGS. 14 and 15 . No interrupting factor generated during executing printing job by the printing apparatus  105  and during bookbinding by the casing-in bookbinding apparatus  103  has been shown in  FIGS. 14 and 15 . However, during the printing and the casing-in bookbinding (correctively referred to as the printing processing below), the interrupting factors such as sheet conveying errors (jamming) may be generated in practice.  FIG. 16  shows that the CPU  205  determines whether the printing interrupting factor is generated during the printing, and the bookbinding system  2000  operates so as to restart the printing. 
   At Step S 1601 , the CPU  205  determines whether the interrupting factor is generated during the printing processing executed based on the printing job. The interrupting factor herein designates defective operations in the bookbinding system  2000 , such as conveying errors of the sheet S in the conveying paths of the printing apparatus  105  and the stacker  104 . In order to determine the generation of the interrupting factor, the CPU  205  determines whether the conveying error is generated, using a sensor (not shown) provided in the conveying paths  331  to  335  of the printing apparatus  105  (or the conveying path of the stacker  104 ). For example, when the sensor on the conveying path  331  continues to detect a sheet for a predetermined time, the CPU  205  determines that it is the conveying error. Also, in order to determine the generation of the interrupting factor, the CPU  205  determines the defective operation of the bookbinding system  2000 . For example, when receiving the device malfunction as a status from the CPU of the casing-in bookbinding apparatus  103 , the CPU  205  determines that the defective operation is generated in the casing-in bookbinding apparatus  103 . 
   At Step S 1602 , the CPU  205  stops the printing processing by the bookbinding system  2000 . For example, when the printing job is the casing-in bookbinding job, the CPU  205  stops the entire bookbinding system  2000  including the casing-in bookbinding apparatus  103 . 
   At Step S 1603 , the CPU  205  informs an operator of the bookbinding system  2000  about the printing interruption via the display screen (LED, etc.) of the operation unit  204 . Upon this information, it is desirable that the display screen of the operation unit  204  clearly specify the interruption factor. For example, when the conveying defect (jamming) is generated in the conveying path  331  of the printing apparatus  105 , it is desirable to inform this fact along with the removing method of the sheet. 
   At Step S 1604 , the CPU  205  determines whether the interrupted printing job is the casing-in bookbinding job on the basis of the printing processing condition information included in the printing job. For example, when the computer terminal  233  establishes the casing-in bookbinding as a printing processing condition by the printer driver  1003 , the printing job includes the casing-in bookbinding information as the printing processing condition information. When the printing processing condition information includes the casing-in bookbinding, the process proceeds to Step S 1605 ; if not, the process proceeds to Step S 1606 . 
   At Step S 1605 , the CPU  205  determines whether the accumulated sheet is used for restarting printing when the interrupted printing job is the casing-in bookbinding job. The computer terminal  233  adds the disposal method when the casing-in bookbinding is interrupted upon executing the printing job by the printer driver  1003  to the printing processing condition information. When the printing job includes the information that the accumulated sheet is used, the process proceeds to Step S 1606 ; if not, the process proceeds to Step S 1608 . 
   At Steps S 1606  and S 1608 , the CPU  205  determines whether the interrupting factor of the printing has been cancelled or not. For example, when the printing is interrupted due to the conveying sheet defect generated in the conveying path  331  of the printing apparatus  105 , it is determined by the sensor provided on the conveying path  331 . When the sheet S is not detected in the conveying path  331 , the CPU  205  determines that the interrupting factor is cancelled due to the removal of the defective sheet. For example, when the printing is interrupted due to a malfunction generated in the casing-in bookbinding apparatus  103 , the status of the casing-in bookbinding apparatus  103  is to be determined. When receiving a status signal indicating that the apparatus restores the normal state from the CPU of the casing-in bookbinding apparatus  103 , the CPU  205  determines the canceling of the interrupting factor. When the CPU  205  determines the canceling of the interrupting factor at Step S 1606 , the process proceeds to Step S 1607 ; when the CPU  205  determines the canceling of the interrupting factor at Step S 1608 , the process proceeds to Step S 1607 , the process proceeds to Step S 1609 . 
   The operations during the restarting printing will now be described. 
   Step S 1607  is the process executed when the interrupted printing job is not the casing-in bookbinding job or it is the casing-in bookbinding job and the printing is to be restarted using the sheet bundle S 1  accumulated on the accumulating tray  42 . Steps S 1609  and S 1610  are the processes executed when the interrupted printing job is the casing-in bookbinding job and the printing is to be restarted without using the sheet bundle S 1  accumulated on the accumulating tray  42 . 
   First, the operations executed when the printing is restarted using the sheet bundle S 1  accumulated on the accumulating tray  42  will be described. 
   At Step S 1607 , the CPU  205  restarts the printing from the page when the printing is interrupted. The page when the printing is interrupted means herein the page to be sequentially stacked onto the sheet bundles S 1  accumulated on the accumulating tray  42 . When the printing is interrupted, the sheet S already printed by the printing apparatus  105  also exists in the conveying path of the bookbinding system  2000 . When all the sheets existing in the conveying path are removed during the printing interruption, the CPU  205  determines the canceling of the interrupting factor at Step S 1606 . The page when the printing is interrupted may also have another form. For example, it may also be a page, which exists in the printing apparatus  105  when the printing is interrupted, to be discharged onto the stacker  104  in the next. In this case, the sheet already discharged from the printing apparatus  105  is to be conveyed to the accumulating tray  42  after the printing is restarted. Then, the CPU  205  determines the canceling of the interrupting factor when all the sheets existing in the conveying path of the printing apparatus  105  are removed. 
   The operations executed when the printing is restarted without using the sheet bundle S 1  accumulated on the accumulating tray  42  will now be described. 
   At Step S 1609 , the CPU  205  determines whether the sheet bundle S already stacked onto the accumulating tray  42  is removed by an operator of the bookbinding system  2000 . When a sensor (not shown) provided in the accumulating tray  42  does not output the information designating the existing of the sheet S, the CPU  205  determines the removal of the sheet bundle S, and the process proceeds to Step S 1610 . When the printing is interrupted, the sheet S already printed by the printing apparatus  105  also exists in the conveying path of the bookbinding system  2000 . When all the sheets existing in the conveying path are removed during the printing interruption, the CPU  205  determines the canceling of the interrupting factor at Step S 1608 . 
   At Step S 1610 , the CPU  205  restarts the interrupted printing job from the top page. 
   As described above, according to the embodiment, when an interrupting factor is generated for interrupting the printing job, it can be selected whether the economy due to use of the sheets already stacked on the accumulating tray  42  takes the precedence, or the removal of defective bound books due to no use of these sheets takes the priority. 
   When an interrupting factor is generated for interrupting the printing job, it can be determined via the printer driver  1003  whether the sheets already stacked on the accumulating tray  42  are used or not. Thereby, when an operator attaches importance on the economy, the sheet bundles S 1  stacked on the accumulating tray  42  during printing interruption can be used. On the other hand, when the operator dislikes defective bound books, the operator can begin again the printing without using the sheet bundles S 1  stacked on the accumulating tray  42 . 
   In the description above, the method for restarting the printing during the interruption of the casing-in bookbinding is established via the printer driver  1003  of the computer terminal  233 ; alternatively, it may have another form. For example, it may be established (received) via the operation unit  204  of the printing apparatus  105 . In this case, despite the external I/F  202  receives any printing job from the computer terminal  233 , the printing is always restarted by the method established via the operation unit  204 . 
   Second Exemplary Embodiment 
   A second embodiment according to the present invention will be described below. 
   The second embodiment is a modification of the first embodiment and the operations according to this embodiment are the same as those in  FIG. 16 ; however, the operation at Step S 1605  of  FIG. 16  is different from that of the first embodiment. 
   According to the first embodiment, at Step S 1605  of  FIG. 16 , the selection between the use of the accumulated sheet bundle S and no use thereof is made based on the printing condition information included in the printing job or the information established via the operation unit  204 ; whereas, according to the second embodiment, the selection between the use of the accumulated sheet bundle S for forming a bound book and the no use thereof is made in accordance with the printing interrupting factor. 
     FIG. 17  is a table showing the printing interrupting factors and disposal methods corresponding to the factors. The CPU  205  determines whether the accumulated sheet bundle S 1  is used or not with reference to the printing interrupting factor and the table of  FIG. 17 . 
   For example, when the CPU  205  determines the shortage of the developer contained in the developing unit  324  of the printing apparatus  105 , the use of the accumulated sheet is decided. This is because of the large possibility of no sheet defect in the printed sheets stacked on the accumulating tray  42 . 
   For example, when the CPU  205  determines the sheet defect in a conveying path of the printing apparatus  105  or a conveying path of the bookbinding system  2000  other than the printing apparatus  105 , the no use of the accumulated sheet is decided. This is because of the large possibility of the sheet defect, such as damage and contamination, produced when the sheet conveying defect is generated. The selection between the use of the accumulated sheet bundle and the no use thereof may be switched in accordance whether the conveying defect is generated in the printing apparatus  105  or it is generated in a conveying path other than the printing apparatus  105 . For example, when it is generated in the printing apparatus  105 , the use of the accumulated sheet bundle is decided, while when it is generated in other than the printing apparatus  105 , the no use is decided. This is because of the large possibility of the sheet damage and contamination produced when the sheet conveying defect is generated in other than the printing apparatus  105 . 
   When the cassette of the printing apparatus  105  for use in the printing job runs short of stacked sheets (zero sheet, for example), the use of the accumulated sheet bundle is decided. This is because of the large possibility of no sheet defect in the printed sheets stacked on the accumulating tray  42 . 
   When the printing job is interrupted by the instruction of an operator, the use of the accumulated sheet bundle is decided. This is because of the large possibility of no sheet defect in the printing apparatus  105  when the printing is interrupted by the instruction of the operator. 
   As described above, according to the second embodiment, when an interrupting factor is generated for interrupting the printing job, the selection between the use of the accumulated sheet bundle S 1  and no use thereof is made in accordance with the interrupting factor. Thereby, the economy due to use of the sheets already stacked on the accumulating tray  42  and the removal of defective bound books due to no use of these sheets appropriately become compatible with each other in accordance with the interrupting factor. 
   Third Exemplary Embodiment 
   A third embodiment according to the present invention will be described below. 
   The third embodiment is a modification of the first embodiment and the operations according to this embodiment are the same as those in  FIG. 16 ; however, the operation at Step S 1605  of  FIG. 16  is different from that of the first embodiment. 
   According to the first embodiment, at Step S 1605  of  FIG. 16 , the selection between the use of the accumulated sheet bundle S 1  and no use thereof is made based on the printing condition information included in the printing job or the information established via the operation unit  204 ; whereas, according to the third embodiment, the selection between the use of the accumulated sheet bundle S 1  for forming a bound book and the no use thereof is made in accordance with the number of the sheet bundles S 1  accumulated on the accumulating tray when the printing is interrupted. 
     FIG. 18  is a table showing the number of the sheet bundles S 1  stacked on the accumulating tray  42  when the printing is interrupted and stored in the hard disk  209  of the printing apparatus  105  and disposal methods corresponding to the numbers. The CPU  205  determines whether the accumulated sheet bundle S 1  is used or not with reference to the number of the sheet bundles S 1  when the printing is interrupted and the table of  FIG. 18 . 
   Specifically, the CPU  205  counts the number of the sheet bundles S 1  stacked on the accumulating tray  42  from the start of the printing based on the printing job to the interruption of the printing so as to store the counted number of the sheet bundles S in the hard disk  209 . If this number of the sheet bundles S ranges from 1 to 100, the CPU  205  restarts the printing without using the accumulated the sheet bundles S 1 . This is because such a range of the number of the sheet bundles S 1  does not so much deteriorate the economy. On the other hand, if the number of the sheet bundles S 1  ranges from  101  to  200 , the CPU  205  restarts the printing using the accumulated the sheet bundles S 1 . This is because such a range of the number of the sheet bundles S 1  deteriorates the economy so much. In addition, the accumulating tray  42  of the casing-in bookbinding apparatus  103  can stack  200  sheets S thereon as long as the sheet is plain paper. 
   In  FIG. 18 , when the number of the sheet bundles S 1  stacked on the accumulating tray  42  is less than 100, the sheet bundles S 1  stacked on the accumulating tray  42  are not used, while when it is more than 100, the sheet bundles S 1  stacked on the accumulating tray  42  are used. Whereas, in  FIG. 19 , the selection is allowed to an operator. 
   In  FIG. 19 , if the counted number of sheets ranges from 1 to 100 when a printing interrupting factor is generated, the CPU  205  restarts the printing without using the sheet bundles S 1  stacked on the accumulating tray  42 . This is because such a range of the number of the sheets does not so much deteriorate the economy. On the other hand, if the number of the sheets ranges from 181 to 200, the CPU  205  restarts the printing using the accumulated the sheet bundles S 1 . This is because such a range of the number of the sheets deteriorates the economy so much. 
   Furthermore, if the counted number of sheets ranges from 101 to 180 when a printing interrupting factor is generated, the CPU  205  allows an operator of the bookbinding system  2000  to designate whether the sheet bundles S 1  stacked on the accumulating tray  42  is used or the sheet bundle is not used, upon restarting the printing. Specifically, the CPU  205  allows the operation unit  204  to display the screen shown in  FIG. 20  on its display screen. The operator inputs the information designating the restarting the printing using the sheet bundles S stacked on the accumulating tray  42  by pushing down a button  2001  on the screen of  FIG. 20 . On the other hand, the operator inputs the information designating the restarting the printing without using the sheet bundles S stacked on the accumulating tray  42  by pushing down a button  2002  on the screen of  FIG. 20 . When the former is selected, the CPU  205  restarts the printing from the page associated with the printing interrupting factor while when the latter is selected, the CPU  205  restarts the printing from the top page of the printing job. 
   In the description above, the accumulating tray  42  can stack 200 sheets thereon; alternatively, another form may be made. The printing apparatus  105  can employ a plurality of types of the sheet S. The type of the sheet includes a plain sheet, a card board, and a thin sheet. It is assumed that the card board have a thickness twice that of the plain sheet and the thin sheet have a thickness half that of the plain sheet. Thereby, if the accumulating tray  42  can stack 200 plain sheets, it can stack 100 card boards or 400 thin sheets. When with reference to the information designating the type of the sheet S in the printing condition information included in the printing job, the CPU  205  determines the process in accordance with this information, the processing corresponding to the type of the sheet can be accomplished. 
   Specifically, when the type of the sheet S is the card board, if the number of the sheets ranges from 1 to 50, the printing is restarted without using the sheet bundles S 1  stacked on the accumulating tray  42 . On the other hand, when a printing interrupting factor is generated, if the number of the counted sheets ranges from 51 to 100, the CPU  205  restarts the printing using the sheet bundles S 1  stacked on the accumulating tray  42 . 
   Specifically, when the type of the sheet S is the thin sheet, if the number of the sheets ranges from 1 to 200, the printing is restarted without using the sheet bundles S 1  stacked on the accumulating tray  42 . On the other hand, when a printing interrupting factor is generated, if the number of the counted sheets ranges from 201 to 400, the CPU  205  restarts the printing using the sheet bundles S 1  stacked on the accumulating tray  42 . 
   In the description above, the accumulating tray  42  can stack 200 sheets thereon, and the decision between the use of the sheet bundles S 1  stacked on the accumulating tray for restarting the printing and no use thereof is switched at 100-sheets as a break point, for example. However, another form may also be made. Specifically, the break point number may be arbitrarily set by an operator via the operation unit  204 . In this case, the break point may include an arbitrary number such as 20 sheets and 80 sheets. The break point number may also be independently set in accordance with the type of the sheet S. 
   As described above, according to the third embodiment, when an interrupting factor for interrupting the printing job is generated, the selection between the use of the sheet bundles S stacked on the accumulating tray and no use thereof is made for restarting the printing in accordance with the number of the sheets accumulated on the accumulating tray  42 . Thereby, the selection between the economy due to use of the sheets already stacked on the accumulating tray  42  and the removal of defective bound books due to no use of these sheets can be appropriately made. That is, when the number of the sheets is small, even the sheet bundle S 1  is not used, the economy is not affected so much, so that the printing is restarted without using the sheet bundle S 1 . On the other hand, when the number of the sheets is large, if the sheet bundle S 1  is not used, the economy is affected therefrom, so that the printing is restarted using the sheet bundle S 1 . 
   Other Embodiments 
   According to the first to third embodiments described above, in the bookbinding system  2000 , the sheet S conveyed from the printing apparatus  105  is automatically conveyed to the casing-in bookbinding apparatus  103  without operation by an operator. Alternatively, the sheet S may be once discharged onto a discharge tray (not shown) included in the printing apparatus  105  so as to form a sheet bundle S, and the sheet bundle S may be conveyed onto the accumulating tray  42  by the operator. In this case, after the operator accumulates the sheet bundle S 1  onto the accumulating tray  42 , the casing-in bookbinding apparatus  103  executes the casing-in bookbinding using the cover sheet S 2  stacked on the cover sheet stack tray  70 . 
   According to the first to third embodiments, the bookbinding system  2000  includes the casing-in bookbinding apparatus  103  executing the casing-in bookbinding; alternatively, it may have another bookbinding apparatus. For example, it may be a stapling apparatus which executes stapling after the cover sheet S 2  is wrapped around the sheet bundle S 1  without applying an adhesive, instead of bonding a book cover on the backbone region  1002  of the cover sheet S 2  with a laid-out back cover. In this case, the sheet bundle S 1  is aligned with the cover sheet S 2  with stapling wires. It may also be an apparatus, in which a cover sheet with a laid-out book cover is fed from the cover sheet stack tray  70 , so that the sheet bundle S 1  is bound with the cover sheet S 2  with a binder tape. In this case, the sheet bundle S 1  is aligned with the cover sheet S 2  with the binder tape. 
   An end of the present invention is also achieved by feeding a storage medium having a program cord, recorded therein, of the software accomplishing functions of the embodiments described above to a system or an apparatus. In this case, a computer of the system or the apparatus reads out and executes the program cord stored in the storage medium so as to achieve the functions of the embodiments. In this case, the program cord itself read out of the storage medium achieves the functions of the embodiments, so that the storage medium having the program cord stored therein constitutes the present invention. 
   As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims. 
   This application claims the benefit of Japanese Application No. 2006-020970 filed Jan. 30, 2006, which is hereby incorporated by reference herein in its entirety.