Abstract:
An image forming system including a binding section that generates a stack of sheets by accumulating a plurality of sheets and that binds by wrapping the stack of sheets with a cover sheet in the shape of a horizontal U, the image forming system comprising:
       a measurement section to measure the thickness of the stack of sheets;   a spine cover width determining section to determine a spine cover width in the cover sheet based on the thickness of the stack of sheets measured by said measurement section; and   an image forming section to form on the cover sheet a front cover image and a back cover image separating them by a spacing equal to said spine cover width.

Description:
[0001]    This application is based on Japanese Patent Applications No. 2006-17341 filed on Jan. 26, 2006 in Japanese Patent Office, the entire content of which is hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an image forming system that binds a stack of sheets by wrapping it with a cover page in the shape of a horizontal U. 
         [0004]    2. Description of the Related Art 
         [0005]    Binding apparatuses are known (see Patent Document 1) that carry out simple binding of a stack of a plurality of sheets on which images have been formed by a copying machine, or a printer, etc., by wrapping the stack of sheets with a cover page bent in the shape a horizontal U. An outline of a general binding technology is as follows. Firstly, a stack of sheets is prepared by accumulating and aligning a plurality of sheets on which images have been formed. Next, an adhesive such as gum, etc., is coated on one surface of the accumulated and aligned stack of sheets. Further, the cover sheet is conveyed and made to stop at a prescribed position, and the cover sheet is adhered to the surface of the stack of sheets on which the adhesive has been coated. Using this procedure, the stack of sheets and the cover sheet become bonded thereby forming a book. 
         [0006]    An example of a book formed by a binding apparatus is shown in  FIG. 1 .  FIG. 1(   a ) shows the state in which the cover sheet S 2  has not been folded, and  FIG. 1(   b ) shows the state in which the cover sheet S 2  has been folded. S 3  is constituted by the plurality of sheets S 1  and the cover sheet S 2 , and is the form in which the cover sheet S 2  wraps the stack of sheets S 1  in the form of a horizontal U. In the following, S 3  is called a wrapped book. In the final form of the wrapped book S 3 , the side edge part S 1 E of the sheets S 1  and the side edge part S 2 E of the cover sheet S 2  are aligned. The cove sheet S 2  has, as is shown in  FIG. 1(   a ), a front cover area a, a spine cover area b, and a back cover area c. 
         [0007]      FIG. 2  shows a development drawing of the cover sheet S 2 . As is shown in  FIG. 2 , the front cover image G 1  has been formed in the front cover area a, and a back cover image G 2  has been formed in the back cover area c, and the front cover image G 1  and the back cover image G 2  are separated at a spacing X. The spine cover area b is present in between the front cover area a and the back cover area c, and the width of the spine cover area b (hereinafter referred to as the spine cover width) varies depending on the number of sheets S 1  in the book. In other words, it is necessary to determine exactly the spine cover width in order to form the front cover image G 1  and the back cover image G 2  at accurate positions on the cover sheet S 2 . 
         [0008]    As a method of determining the spine cover width, there is the method disclosed in Patent Document 2. In the technology described in Patent Document 2, the size of the spine cover part of the cover sheet is calculated using the data related to the thickness of one sheet, the data related to the toner thickness based on the amount of toner used per sheet, and the number of sheets. 
         [0009]    Patent Document 1: Japanese Unexamined Patent Application Open to Public Inspection No. 2005-335262 
         [0010]    Patent Document 2: Japanese Unexamined Patent Application Open to Public Inspection No. Hei 10-167557 
         [0011]    However, since the spine cover width is affected by the variations in the thickness of one sheet of paper, the amount of curling of the sheet, etc., in the method of calculating it based on the data described in Patent Document 2 and the number sheets, it is not possible to determine exactly the spine cover width, and it is not possible to form the cover sheet image, etc., at an accurate position in the cover sheet. 
       SUMMARY 
       [0012]    Therefore, the purpose of the present invention is to provide an image forming system and an image forming apparatus that increase the accuracy of the spine cover width, and can form the front cover image and the back cover image at more appropriate positions in the cover sheet. 
         [0013]    In order to achieve the above objective, an image forming system according to one preferred embodiment of the present invention is an image forming system including a binding section that generates a stack of sheets by accumulating a plurality of sheets and that binds by wrapping the stack of sheets with a cover sheet in the shape of a horizontal U, the image forming system comprising: 
         [0014]    a measurement section to measure the thickness of the stack of sheets; 
         [0015]    a spine cover width determining section to determine a spine cover width in the cover sheet based on the thickness of the stack of sheets measured by said measurement section; and 
         [0016]    an image forming section to form on the cover sheet a front cover image and a back cover image separating them by a spacing equal to said spine cover width. 
         [0017]    Further, an image forming system according to another preferred embodiment of the present invention is an image forming system including a binding section that generates a stack of sheets by accumulating a plurality of sheets and that binds by wrapping the stack of sheets with a cover sheet in the shape of a horizontal U, the image forming system comprising: 
         [0018]    an input section to input a value of a spine cover width in the cover sheet; 
         [0019]    a measurement section to measure the thickness of the stack of sheets; 
         [0020]    a spine cover width determining section to determine a spine cover width in the cover sheet in an input mode in which the spine cover width determining section determines the spine cover width in the cover sheet based on the value of the spine cover width inputted by said input section or in a measurement mode in which said spine cover width determining section determines the spine cover width based on the thickness of the stack of sheets measured by said measurement section; 
         [0021]    an image forming section to form on the cover sheet a front cover image and a back cover image separating them by a spacing equal to the spine cover width; and 
         [0022]    a control section to carry out switching between the input mode and the measurement mode of said measurement section when a plurality of books are to be bound, wherein said control section controls spine cover determining operation by said spine cover width determining section to operate in the input mode at least for the first book of the plurality of books to be bound. 
         [0023]    Further, an image forming system according to yet another preferred embodiment of the present invention is an image forming system including a binding section that generates a stack of sheets by accumulating a plurality of sheets and that binds by wrapping the stack of sheets with a cover sheet in the shape of a horizontal U, the image forming system comprising: 
         [0024]    an input section to input a value of a spine cover width in the cover sheet; 
         [0025]    a measurement section to measure the thickness of the stack of sheets; 
         [0026]    displaying section to display the value of the spine cover width that has been input by said input section and the result of the measurement of the thickness of the stack of sheets measured by said measurement section; 
         [0027]    a spine cover width determining section to determine a spine cover width in the cover sheet; 
         [0028]    a control section to control said measurement section to measure the thickness of the stack of sheets, and to control said displaying section to display the value of the spine cover width in the cover sheet inputted by said input section and the thickness of the stack of sheets measured by said measuring section after the measurement, and when a value of the spine cover width is inputted again by said input section or when the value of the spine cover width in the cover sheet that has already been inputted by said input section after displaying the value of the spine cover width in the cover sheet inputted by said input section, said control section controls said spine cover determining section to determine the spine cover width in the cover sheet based on the value of the spine cover width inputted again or the value of the spine cover width in the cover sheet that has already been inputted; and 
         [0029]    an image forming section to form on the cover sheet a front cover image and a back cover image separating them by a spacing equal to the spine cover width in the cover sheet determined by said determining section. 
         [0030]    According to an image forming system of the present invention, it is possible to increase the accuracy of the spine cover width, and to form the front cover image and the back cover image at more appropriate positions in the cover sheet. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]      FIG. 1  is a detailed diagram of the wrapped book S 3 . 
           [0032]      FIG. 2  is a development diagram of the cover sheet s 2 . 
           [0033]      FIG. 3  is a center cross-section diagram of an image forming apparatus. 
           [0034]      FIG. 4  is an explanatory diagram showing the process of coating an adhesive on the stack of sheets S 1 . 
           [0035]      FIG. 5  is a detailed diagram of the display screen in the operation section A 4 . 
           [0036]      FIG. 6  is a detailed diagram of the display screen in the operation section A 4 . 
           [0037]      FIG. 7  is a detailed diagram of the display screen in the operation section A 4 . 
           [0038]      FIG. 8  is a detailed diagram of the display screen in the operation section A 4 . 
           [0039]      FIG. 9  is a block diagram of the control section in the image forming system. 
           [0040]      FIG. 10  is an explanatory diagram showing the relationship of outputting the images and the sheets S 1  and the cover sheet S 2  in the wrapped book S 3 . 
           [0041]      FIG. 11  is a flow chart showing the operation of measuring the thickness of the stack of sheets S 1 . 
           [0042]      FIG. 12  is an explanatory diagram related to the operation of the first gripping plate  502  and the second gripping plate  503 . 
           [0043]      FIG. 13  is a flow chart describing the operation of determining the spine cover width. 
           [0044]      FIG. 14  is an explanatory diagram of the spine cover width input mode in the operation section A 4 . 
           [0045]      FIG. 15  is a flow chart showing the binding operations using the input mode and the measurement mode. 
           [0046]      FIG. 16  is an explanatory diagram of the spine cover width input mode in the operation section A 4 . 
           [0047]      FIG. 17  is a flow chart showing the binding operations in which the spine cover width can be input again or can be set again. 
           [0048]      FIG. 18  is a flow chart describing the alarm operations at the time the spine cover width is input. 
           [0049]      FIG. 19  is an explanatory diagram of the alarm messages in the operation section A 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0050]      FIG. 3  is a center cross-section diagram of an image forming apparatus. 
         [0051]    The image forming system has an image forming apparatus (image forming section) A and a binding apparatus (binding section) B. 
         [0052]    The image forming apparatus A forms images on sheets using the electro-photographic method, and has an image forming section A 1 , an original document conveying section A 2 , and an image reading section A 3 . In the image forming section A 1 , a charging unit  2 , an exposure unit  3 , a developing unit  4 , a transfer unit  5 A, a separator unit  5 B, and a cleaning unit  6  are placed around a drum-shaped photoreceptor body  1 , and each of the processes of charging, exposure, developing, and transferring are carried out, and toner images are formed on the sheets S 1  and the cover sheet S 2 . The sheets S 2  that are the intermediate sheets when wrapped by the cover sheet S 2  if binding is done are stored in two sheet feeding trays  7 A, and the cover sheets  32  are stored in the sheet feeding tray  7 B and in the cover sheet storage section  80  of the binding apparatus B. One sheet each of the sheets S 1  and the cover sheet S 2  are discharged at a time from the sheet feeding trays  7 A and  7 B and are transported to the image forming section A 1 . The sheet S 1  and the cover sheet S 2  on which toner images have formed are subjected to fixing process by passing through the fixing unit  8 . The sheet S 1  and the cover sheet S 2  that have been fixed are discharged to outside the image forming apparatus A by the sheet discharge rollers  7 C. 
         [0053]    The binding apparatus B accumulates a plurality of sheets S 1  sent from the image forming apparatus A thereby making a stack of sheets, affixes a cover sheet S 2  on this stack of sheets by wrapping the stack of sheets with the cover sheet S 2  in the shape of a horizontal U thereby preparing a book. The binding apparatus B has a sheet reversing section  40 , an accumulation section  50 , a coating section  60 , and a joining section  90  that affixes a cover sheet on the stack of sheets, and, in addition, it also has a conveying section  10 , a sheet discharge tray  20 , a cover sheet storage section  80 , and a book discharging section  100 . The sheets S 1  conveyed from the image forming apparatus A to the binding apparatus B are either discharged to the sheet discharge tray  20  via the sheet discharge path  12  or are conveyed to the sheet reversing section  40  by the selection gate  11  provided in the conveying section  10 . The sheets S 1  are discharged to the sheet discharge tray  20  when no book binding is to be done in the binding apparatus B. When a book binding operation is to be made in the binding apparatus B, the sheets S 1  are conveyed to the sheet reversing section  40  via the conveying path  13 , and after being switched back in the sheet reversing section  40 , they are conveyed to the accumulation section  50 . In the accumulation section  50 , a set number of sheets S 1  is accumulated, the accumulation section rotates when the number of sheets S 1  accumulated reaches a set number, and the stack of sheets S 1  is held in an almost vertical position. Next, an adhesive material is coated by the coating section  60  on the bottom surface of the stack of sheets S 1  which is the spine part of the book to be prepared, and a cover sheet S 2  is contacted with and adhered to the stack of sheets S 1 . The wrapped book S 3  prepared by adhering the cover sheet S 2  to the stack of sheets S 1  is discharged to the book discharging section  100 . 
         [0054]      FIG. 4  shows the process of coating an adhesive on the stack of sheets S 1 . 
         [0055]    The second gripping member  503  is moved towards the sheet S 1  by the motor M 1  which is the moving means, and when the second gripping member  503  pushes against the sheet S 1  with a constant pressure, the increase in the driving torque of the motor M 1  is detected by the driving torque detection sensor (not shown in the figure), and the movement of the second gripping member  503  is stopped. Because of this configuration, the stack of sheets S 1  is gripped strongly between the first gripping member  502  and the second gripping member  503 . The amount of movement of the second gripping member is measured by an encoder, and is stored in a storage section such as a RAM, etc. The detailed contents related to the method of measuring the thickness of a stack of sheets S 1  are described later. 
         [0056]    At the stage when the stack of sheets S 1  is gripped by the first gripping member  502  and the second gripping member  503 , the receiving plate  506  is rotated by 90 degrees by a driving mechanism (not shown in the figure), and recedes as is shown in  FIG. 4(   b ). At the stage in which the receiving plate  506  has receded, the coating roller  62  and the bottom surface SA of the stack of sheets S 1  are not in contact with each other (see  FIG. 4(   c )). 
         [0057]    Next, as is shown in  FIG. 4(   d ), the coating section  60  in which is stored the adhesive material  63  rises up and the coating roller  62  comes into contact with the bottom surface SA of the stack of sheets S 1 , and the adhesive material  63  is coated on the bottom surface SA of the stack of sheets S 1  because of the coating section  60  moving along the bottom surface SA of the stack of sheets S 1 . The coating roller  62  is driven by the motor M 2 . 
         [0058]    Next, the method of making settings for the book binding operation in the operation section are described below referring to  FIG. 5  to  FIG. 8 . 
         [0059]      FIG. 5  to  FIG. 8  are the detailed drawings of the display screen in the operation section A 4 . 
         [0060]      FIG. 5  shows the basic screen of the operation section A 4  that is the display section and the input section. When carrying out a book binding operation, to begin with the application function button A 41  is pressed. When the application function button A 41  is pressed, the settings screen related to the application function is displayed as shown in  FIG. 6 , and next the finishing operation button A 42  is pressed in the settings screen. When the finishing operations button A 42  is pressed, the settings screen related to the finishing operations is displayed as shown in  FIG. 7 . When wanting to carry out book binding operation of wrapping the cover sheet S 2  over the sheets S 1  as is shown in  FIG. 1 , the PERFECT BINDING button A 43  is to be pressed in the settings screen. When the wrap stitching button A 43  is pressed, the settings screen related to wrap stitching is displayed as is shown in  FIG. 8 , and the settings are completed when the presence or absence of cover sheet printing, cover sheet printing surface, presence or absence of cover sheet cutting, etc., are set and the OK button is pressed in this screen. 
         [0061]      FIG. 9  is a block diagram of the control section in the image forming system. 
         [0062]    The image forming apparatus A is connected to PC which is a terminal such as a personal computer and to the binding apparatus B. When the image is input to the print controller A 5  from the PC via communication lines such as a LAN, etc., the CPU  101 , which is the control section and the spine cover determining section, causes the DRAM control IC  102  and the compression and decompression IC  103  to operate, and the input image is stored in the compression memory within the image memory  104 . On the other hand, if the image is input after an original document is read in by the image reading section A 3 , the input image is processed by the read processing section  108 , and is then stored in a similar manner in the compression memory within the image memory  104 . When forming the stored images on a sheet S 1 , etc., the compressed image is decompressed by the compression and decompression IC  103  and is expanded in the page memory within the image memory  104 . Next, based on the image memory expanded in the page memory, the CPU  101  controls the image formation control section within the image forming section A 1 , and the image is formed on the sheet S 1 , etc. Apart from the image memory  104 , the CPU  101  is connected to a program memory  105  that stores the programs carrying out the sequence of operations in the image forming system, and to a system memory  106 . The binding apparatus controlling section B 1  of the binding apparatus B is connected to the image formation controls section of the image forming section A 1 , and carries out the book binding operations in relation to the image forming section A 1 . 
         [0063]      FIG. 10  is an explanatory diagram showing the relationship of outputting the images and the sheet S 2  and the cover sheet S 2  in the wrapped book S 3 . 
         [0064]      FIG. 10(   a ) expresses in units of one page the image data in one print job, and such image data is present for N number of pages in all. The first page corresponds to the font cover sheet image, and the last Nth page corresponds to the back cover sheet image. Therefore, the second page up to the (N-1)th page are output as the intermediate sheets S 1  that are wrapped by the cover sheet S 2  (see  FIG. 10(   b )). Next, the front cover sheet image of the first page and the back cover sheet image of the Nth page are output to the cover sheet S 2 . At the time of outputting the front cover sheet image and the back cover sheet image to the cover sheet S 2 , firstly, the front cover sheet image and the back cover sheet image compressed in the image memory  104  are decompressed, and are expanded in the page memory of the image memory  104  as is shown in  FIG. 10(   c ). Since it is necessary to acquire a spine cover area in between the front cover sheet area and the back cover sheet area as is shown in  FIG. 2 , the spine cover width X determined by the CPU  101  is inserted in between the front cover sheet image and the back cover sheet image within the page memory. Thereafter, image formation is done on the cover sheet S 2  based on this image information. 
         [0065]    The spine cover width X in the cover sheet S 2  corresponds to the thickness of the stack of sheets S 1 , and unless this spine cover width X is determined accurately, it is not possible to form the front cover sheet image and the back cover sheet image at an accurate position in the cover sheet S 2 . In view of this, it is desirable that the thickness of the stack of sheets S 1  is measured, and the spine cover width X is determined based on the result of this measurement. 
         [0066]    The operation of measuring the thickness of the stack of sheets S 1  is explained here referring to  FIG. 11  and  FIG. 12 . 
         [0067]      FIG. 11  is a flow chart showing the operation of measuring the thickness of the stack of sheets S 1 , and  FIG. 12  is an explanatory diagram related to the operation of the first gripping plate  502  and the second gripping plate  503 . In order to make the method of measurement easy to understand, the unnecessary members have been omitted in  FIG. 12 . 
         [0068]      FIG. 12(   a ) shows the state in which the stack of sheets S 1  has not been accumulated between the first gripping member  502  and the second gripping member  503 , and both gripping members are in the inclined condition. Further, the second gripping member  503  is at the initial position. In this condition, the measurement operation of measuring the initial spacing A between the first gripping member  502  and the second gripping member  503  is carried out. To begin with, when the power supplies of the binding apparatus, etc., within the image forming system area switched ON (Step S 1  in  FIG. 11) , the program measuring the initial spacing A is read out from the program memory  105 , and the CPU  101  executes the measurement operations. The CPU  101  drives the motor M 1  and moves the second gripping member  503  towards the first gripping member  502  (Step S 2  in  FIG. 11 ). Next, it detects whether or not the drive torque of the motor M 1  has reached a prescribed torque value using the driving torque detection sensor (not shown in the figure) (Step S 3  in  FIG. 11 ). When the drive torque of the motor M 1  is detected to have reached the prescribed value, the movement of the second gripping member  503  is stopped (Step S 4  in  FIG. 11 ). When the movement of the second gripping member  503  has stopped, the first gripping member  502  and the second gripping member  503  are in the condition in which they are in contact with each other as is shown in  FIG. 12(   b ). Since the amount of movement of the second gripping member has been measured by the encoder  509 , this amount of movement becomes the initial spacing A between the first gripping member  502  and the second gripping member  503  (Step S 5  in  FIG. 11) . The measured initial spacing A is stored in the system memory  106 . When the measurement of the initial spacing is completed, the second gripping member  503  is returned to its initial position in order to accumulate the stack of sheets S 1  (Step S 6  in  FIG. 11 ). Next, when the accumulation of the stack of sheets S 1  is completed (Step S 7  in  FIG. 11 ), the unit is rotated with the shaft  501  as the center, so that the first gripping member  502  and the second gripping member  503  change from the inclined position to an almost vertical position while maintaining the initial spacing A between the two gripping members. Next, the program for measuring the thickness of the stack of sheets S 1  is read out from the program memory  105 , and the measuring operations by the measurement section B 2  of the binding apparatus B are executed. To do this, to start with, the second gripping member  503  is moved towards the first gripping member  502  (Step S 8  in  FIG. 11 ). Next, a detection is made as to whether or not the drive torque of the motor M 1  has reached a prescribed torque value using the driving torque detection sensor (Step S 9  in  FIG. 11 ). When the drive torque of the motor M 1  is detected to have reached the prescribed value, the movement of the second gripping member  503  is stopped (Step S 10  in  FIG. 11 ). When the movement of the second gripping member  503  has stopped, the second gripping member  503  and the stack of sheets S 1  are in the condition in which they are in contact with each other as is shown in  FIG. 12(   d ). The amount of movement (B in  FIG. 12(   c )) of the second gripping member has been measured by the encoder  509  (Step S 11  in  FIG. 11) . Next, the value of the initial spacing A that has already been measured is read out from the system memory  106 , and the thickness of the stack of sheets S 1  is calculated by subtracting the amount of movement B from the initial spacing A (Step S 12  in  FIG. 11 ). Although the method of measurement shown in  FIG. 12  is one in which the thickness of the stack of sheets S 1  is measured by moving the second gripping member  503  using a motor M 1 , it is not necessary to restrict to the mode of moving the second gripping member  503 , but it is also possible to have a mode in which the first gripping member  502  is moved. In addition, it is also possible to have a mode of measuring the thickness of the stack of sheets S 1  in which a motor and an encoder are connected to both the first gripping member  502  and the second gripping member  503  and the thickness of the stack of sheets S 1  is measured by moving both the gripping members. 
         [0069]    Further, in the present preferred embodiment, although the descriptions have been given that the program for measuring the initial spacing A is read out from the program memory  105  and the CPU  101  carries out the measurement operations, it is also possible to store the program for measuring the initial spacing A in the program memory (not shown in the Figure) that has been provided in the binding apparatus control section B 1  of the binding apparatus B, and the program is read out from that program memory, and the measurement operations are carried out by the binding apparatus control section B 1 . 
         [0070]    Next, the operation of determining the spine cover width is described using the flow chart shown in  FIG. 13 . 
         [0071]    To begin with, the image is input from a PC, etc. (Step S 21 ), and when all the image data in one print job are received, the images of pages 2 to N-1 are formed on the sheets S 1  (Step S 22 ). Next, a judgment is made as to whether or not the sheets S 1  for the pages 2 to N-1 have been accumulated in the accumulation section  50  (Step S 23 ), and when it is judged that the accumulation has been completed (Step S 25 ), the thickness of the stack of sheets S 1  is measured (Step S 24 ) using the measurement method described regarding  FIG. 11  and  FIG. 12 . Next, the images of page 1 and page N are synthesized and expanded in the page memory (Step S 25 ), and a spine cover width according to the thickness of the stack of sheets S 1  calculated in Step S 12  is inserted (Step S 26 ). For this spine cover width, it is possible to take a value equal to the thickness of the stack of sheets S 1  as the spine cover width in the cover sheet S 2 , or else, it is possible to take as the spine cover width a value obtained by adding to the measured thickness of the stack of sheets S 1  an amount corresponding to the thickness of the cover sheet S 2  (for example, 0.1 mm to 2 mm), and if the spine cover width is determined in this manner, in the final condition of the wrapped book S 3 , the side edge part S 1 E of the sheets S 1  and the side edge part S 2 E of the cover sheet S 2  will be aligned. In the condition in which the spine cover width has been inserted, the image to be formed on the cover sheet S 2  will have become complete, and the image formation of this image is carried out on the cover sheet S 2  (Step S 27 ). Next, the binding operations of coating the adhesive material, etc., are carried out (Step S 28 ). The sequence of operations is ended when the output has been completed for the set number of books (Step S 29 ). 
         [0072]    As has been explained above, by measuring the thickness of the stack of sheets, and by determining the spine cover width according to the result of that measurement, it is possible to form the front cover sheet image and the back cover sheet image at accurate positions on the cover sheet S 2 . 
         [0073]    However, according to the method of measurement explained regarding  FIG. 11  and  FIG. 12 , although it is possible to determine accurately the spine cover width, since it is not possible to measure the thickness of the stack of sheets until the image formation on all the sheets S 1  has been completed, it is not possible to carry out the image formation operations on the cover sheet S 2 , and hence it is not possible to achieve improvement in the productivity of producing wrapped books S 3 . Considering this point, it is desirable to execute the input mode at least for the first copy of the book wherein the spine cover width is determined based on the value of the spine cover width that has been input. 
         [0074]    The method of making the settings of the input mode is explained here referring to  FIG. 8  and  FIG. 14 . A spine cover width input mode button A 44  has been provided in the settings screen related to the settings for wrap-stitching shown in  FIG. 8 . When the spine cover width input mode button A 44  is pressed, the settings screen related to the spine cover width input mode is displayed as is shown in  FIG. 14 . When the spine cover width button A 45  is pressed, it is possible to input concretely a numeric value for the spine cover width, and the value of the spine cover width that has been input is displayed in the cover sheet window A 46 . In addition, it is also possible to set whether or not to stop temporarily the book binding operations in the image forming system in order to verify the wrapped book S 3  that has been bound in the input mode. 
         [0075]      FIG. 15  is a flow chart showing the operations of binding using the input mode and the measurement mode. 
         [0076]    To begin with, the spine cover width is entered in the screen of the spine cover width input mode shown in  FIG. 14  (Step S 31 ), and an input is made selecting whether or not to stop temporarily the book binding operations in the image forming system at the point when the first copy of the wrapped book S 3  that has just been bound has been output (Step S 32 ). Next, the printing operation is started (Step S 33 ), when the image is input from the PC, etc. (Step S 34 ), first the images of pages 2 to N-1 are formed on the sheets S 1  (Step S 35 ), and then the images of page 1 and page N are synthesized and expanded in the page memory (Step S 36 ). Further, in case images are to be formed not only on the top surface of the cover sheet but also images are to be formed on the inside surfaces of the cover sheet, first the images of pages 3 to N-2 are formed on the sheets S 1 , next the images of page 1 and page N are synthesized, and finally, the images of page 2 and page N-1 are synthesized and expanded in the page memory. Thereafter, a judgment is made as to whether or not it is the output of the first copy of the book (Step S 37 ), and if it is the output of the first copy, the spine cover width is inserted between the front cover sheet image and the back cover sheet image using the value of the spine cover width input in the operation section A 4  (Step S 38 ). Since the image in the cover sheet S 2  gets completed when the spine cover width is inserted, the image forming is carried out on the cover sheet S 2  based on this image (Step S 39 ). Next, the binding operations such as coating the adhesive material, etc., are carried out (Step S 40 ). Although not shown in the flow in  FIG. 15 , between steps S 39  and S 40 , the thickness of the stack of sheets S 1  is measured according to the method of measurement described regarding  FIG. 11  and  FIG. 12 . In Step S 41 , a judgment is made as to whether or not the output of the first copy has been completed, and if it is judged that the output of the first copy has been completed, a judgment is made as to whether or not the temporary stop operation has been set in the operation section A 4  (Step S 42 ), and if temporary stop has not been set, the image forming system continues to carry out the output of the second and subsequent copies of the book without making a temporary stop of the operations. If a temporary stop has been set, the binding operations in the image forming system are stopped temporarily, the settings verification screen corresponding to that shown in  FIG. 14  is displayed in the operation section A 4  (Step S 43 ), and the user is prompted to verify the finish of the wrapped book S 3  prepared in the input mode. Thereafter, when the Start button is pressed (Step S 44 ), the binding operations for the second and subsequent copies are restarted. At the time of executing the binding operations for the second and subsequent copies, since the thickness of the stack of sheets S 1  has already been measured, the mode changes to the measurement mode, the spine cover width is inserted based on the result of that measurement (Step S 45 ), and the image formation of the cover sheet (Step S 46 ) and the binding operations are executed (Step S 47 ). Further, for this spine cover width, it is possible to take a value equal to either the input value of the spine cover thickness or the measured value of the thickness of the stack of sheets S 1  as the spine cover width in the cover sheet S 2 , or else, it is possible to take as the spine cover width a value obtained by adding to the input value of the spine cover width or the measured thickness of the stack of sheets S 1  an amount corresponding to the thickness of the cover sheet S 2  (for example, 0.1 mm to 2 mm). 
         [0077]    In this manner, by carrying out binding operations for the first copy in the input mode, it is possible to achieve improvement in the productivity of producing the wrapped book S 3 , and since the operations are executed in the measurement mode of determining the spine cover width using the result of measurement of the thickness of the stack of sheets S 1  for the second and subsequent copies, it is possible to form the front cover sheet image and the back cover sheet image at accurate positions in the cover sheet S 2 . 
         [0078]    Further, there is the need that the user may want to prepare the final wrapped book S 3  while confirming the finish after inputting the spine cover width. In this case, it is desirable that carry out binding operations that permit inputting the spine cover width several times. 
         [0079]      FIG. 16  is an explanatory diagram of the spine cover width input mode in the operation section A 4  which is different from that of  FIG. 14 . 
         [0080]    When the spine cover width input mode button A 44  is pressed in the settings screen related to the settings for wrap-stitching shown in  FIG. 8 , a settings screen is displayed as is shown in  FIG. 16  which is different from that shown in  FIG. 14 . When the spine cover width button A 45  is pressed, it is possible to input concretely a numeric value for the spine cover width, and the value of the spine cover width that has been input is displayed in the cover sheet window A 46 , which is identical to the case shown in  FIG. 14 , but a detection window A 47  has been provided next to the cover sheet window A 46 . The result of measurement of the thickness of the stack of sheets S 1  is displayed in this detection window A 47 , and it is possible to input again the spine cover width by pressing the spine cover width button A 45  based on this displayed value. In addition, the Change Setting button A 48 , which is the button for inputting the value again, makes it possible to set the value of the result of measurement displayed in the detection window A 47  as it is as the value of the spine cover width, and hence it becomes easy to set again the spine cover width. When the Change Setting button A 48  is pressed, the values in the cover sheet window A 45  and the detection window A 47  become identical. 
         [0081]      FIG. 17  is a flow chart showing the binding operations in which the spine cover width can be input again or can be set again. 
         [0082]    The operations in Steps S 51  to S 56  are identical to the operations of the Steps S 31  to S 36  described regarding  FIG. 15 . In Step S 57 , the spine cover width is inserted between the front cover sheet image and the back cover sheet image based on the value of the spine cover width input in the operation section A 4 . Since the image in the cover sheet S 2  gets completed when the spine cover width is inserted, the image forming is carried out on the cover sheet S 2  based on this image (Step S 58 ). Next, the binding operations such as coating the adhesive material, etc., are carried out (Step S 59 ), a judgment is made as to whether or not the output for the set number of copies has been completed (Step S 60 ), and the binding operations are ended if it is judged that the output for the set number of copies has been completed. If it is judged that the output for the set number of copies has not been completed in Step S 60 , a judgment is made as to whether or not temporary stop is active (Step S 61 ). If no temporary stop has been specified, the image forming system continues the binding operations for the next and subsequent copies. If a temporary stop has been specified, the spine cover width value that has been input and the result of measurement of the thickness of the stack of sheets S 1  are displayed in the operation section A 4  (Step S 62 ), and the settings screen of  FIG. 16  is displayed. Next, a judgment is made as to whether or not the spine cover width is to be input again after observing the wrapped book S 3  that has actually been output (Step S 63 ). When the spine cover width is input again by pressing the spine cover width button A 45  or the Change Setting button A 49 , that value that has been input again is set as the spine cover width for the next and subsequent copies (Step S 64 ), and if the spine cover width is not input again, the spine cover width that has already been input is set again as the spine cover width for the next and subsequent copies (Step S 65 ). When the input of whether or not to make a temporary stop is made (Step S 66 ) and then the Start button is pressed again (Step S 67 ), the book binding operations are started in the image forming system. In this manner, the operations from Step S 55  to Step S 67  are repeated until the output for the set number of copies has been completed. Further, for this spine cover width, it is possible to take a value equal to either the input value of the spine cover thickness or the measured value of the thickness of the stack of sheets S 1  as the spine cover width in the cover sheet S 2 , or else, it is possible to take as the spine cover width a value obtained by adding to the input value of the spine cover width or the measured thickness of the stack of sheets S 1  an amount corresponding to the thickness of the cover sheet S 2  (for example, 0.1 mm to 2 mm). 
         [0083]    As has been explained above, by executing the binding operations shown in  FIG. 17 , it is possible to input the spine cover width several times, and it is possible for the user to input the spine cover width and verify the finish of the resultant wrapped book S 3 , and then to prepare the final wrapped book S 3 . 
         [0084]    As is shown in  FIG. 16 , the result of measurement of the thickness of the stack of sheets S 1  is displayed in the detection window A 47 , and it is possible to input again the spine cover width based on this displayed value by pressing the spine cover width button A 45  (Step S 63  in  FIG. 17 ). At the time of inputting again the spine cover width, if the user inputs by mistake a value for the spine cover width that is far different from the result of measurement, the front cover sheet image and the back cover sheet image are formed at positions far different from the correct positions on the cover sheet S 2 , and hence the wrapped book that is output will be wasted. In view of this, it is desirable that an alarm is given to the user when the input value of the spine cover width is widely different from the result of measurement of the thickness of the stack of sheets S 1 . 
         [0085]      FIG. 18  is a flow chart describing the alarm operations at the time the spine cover width is input. 
         [0086]    To begin with, the thickness of the stack of sheets S 1  is measured using the method of measurement described regarding  FIG. 11  and  FIG. 12  (Step S 71 ), and the spine cover width that has been input and the result of measurement of the stack of sheets S 1  are displayed in the operation section A 4  (Step S 72 ). Thereafter, when the user inputs again or sets again the spine cover width using the operation section A 4  (Step S 73 ), the spine cover width value that has been input again or set again is compared with the thickness of the stack of sheets S 1  that has been measured (Step S 74 ). Although the binding operations are carried out if these are not different from each other by more than a prescribed value (Step S 78 ), if they are different by more than the prescribed value, an alarm message is displayed in the operation section A 4  as is shown in  FIG. 19  (Step S 75 ). Although in the present preferred embodiment the operation section A 4  is functioning as an alarm section, it is also possible to emit an alarm sound. In addition, in case the alarm message is displayed by the operation section A 4 , it is also possible to make the display screen red in order to make the user realize the alarm. After the alarm message is output, a judgment is made as to whether or not the spine cover width is input or not (Step S 76 ). As is shown in  FIG. 19 , the print execute button A 49  and the Re-input spine cover width button A 50  are displayed, and if the print execute button A 49  is pressed, the binding operations are carried out as it is with the spine cover width value for which the alarm was generated (Step S 78 ), and if the Re-input spine cover width button A 50  is pressed, the settings screen shown in  FIG. 16  is displayed thereby making it possible to set the spine cover width again. After the Re-input spine cover width button A 50  button is pressed and the spine cover width has been set again, the binding operations are carried out with that spine cover width value that has been set again (Step S 77 ). 
         [0087]    By carrying out the operations shown in  FIG. 18  in this manner, it is possible to give an alarm to the user if the input value of the spine cover width and the result of measurement of the thickness of the stack of sheets S 1  are widely different, and hence it is possible to prevent the formation of a wrapped book S 3  that becomes a waste. 
         [0088]    Although the content of the present invention was explained in  FIG. 3  to  FIG. 17  based on an image forming system with a binding apparatus B and an image forming apparatus A connected together, similar results are provided even when the binding apparatus B and the image forming apparatus A are integral thereby constituting a single image forming apparatus. In other words, the present invention can be realized in a similar manner to that of an image forming system even in an image forming apparatus that is provided with a binding section and an image forming section.