Patent Publication Number: US-8109311-B2

Title: Bookbinding apparatus and image forming system

Description:
RELATED APPLICATION 
     The present application is based on Patent Application No. 2008-308310 filed at the Japan Patent Office on Dec. 3, 2008 and which is hereby incorporated herein in its entirety. 
     TECHNICAL FIELD 
     The present invention relates to an image forming system and a Bookbinding apparatus. 
     The image forming system includes an image forming apparatus for forming an image on a sheet and a bookbinding apparatus for receiving the sheet onto which the image forming apparatus has formed the image and performing a bookbinding process on the sheet. 
     BACKGROUND 
     In a printing field called POD (print on demand), the image forming system configured by the image forming apparatus and the bookbinding apparatus creates a book without using a printing plate. 
     For example, as disclosed in Unexamined Japanese Patent Application Publication No. 2008-80603, many of the bookbinding apparatuses for POD use a gluing apparatus as a device for bookbinding the sheet bundle with a binding process. Since the structure of the gluing apparatus is simple and small, the gluing apparatus is suitable for combining into the image forming apparatus. 
     In Unexamined Japanese Patent Application Publication No. 2008-80603, a temperature of an adhesive storage section heater, a temperature of an application device heater and a temperature of adhesive are separately detected in an application apparatus that includes the adhesive storage section heater and the application device heater. The above mentioned adhesive storage section heater and the above mentioned application device heater are separately controlled based on the detection temperature. Thus, the temperature of the adhesive in the adhesive storage section becomes even and the adhesive is quickly melted. 
     In Unexamined Japanese Patent Application Publication No. H10-35138, a warm-up time is shortened and the power consumption is controlled by having different number of heaters for the warm-up time and an application time. 
     Also as pointed out in Unexamined Japanese Patent Application Publication No. H10-35138, shortening of the wait time, which is from when the adhesive heating device is turned on to when the adhesive is melted and becomes ready to be applied, is a technical object needed to be solved in the bookbinding apparatus using a gluing apparatus. 
     The wait time is the time from when a heating device for heating the adhesive is turned on to when the temperature of the adhesive rises to the temperature in which the adhesive become applicable, namely, a warm-up time. In Unexamined Japanese Patent Application Publication No. 2008-80603 and Unexamined Japanese Patent Application Publication No. H10-35138, the warm-up time is shortened by using a plurality of heaters as the heating device and controlling the plurality of heaters separately. 
     However, there is a limitation in such warm-up time shortening device. Thus, the warm-up time cannot be shortened enough. 
     As described above, in the warm-up, the adhesive is heated until the temperature of the adhesive reaches the application temperature. Therefore, the application temperature is set as a standard of the control. The warm-up completes when the adhesive temperature is detected to have reached the standard temperature. 
     In such warm-up control, in order to shorten the warm-up time, the speed of raising the temperature needs to be increased. Therefore, there is a need to increase the power of the heater. Thus, an increase in power consumption cannot be avoided. 
     In Unexamined Japanese Patent Application Publication No. 2008-80603, the plurality of heaters is separately controlled so that the adhesive temperature is uniformly raised and the warm-up time can be shortened. However, in order to shorten the warm-up time, the number of heaters or the power of the heater needs to be increased. Since Unexamined Japanese Patent Application Publication No. H10-35138 is in the similar manner, a heater that is turned on only at the warm-up time is needed. Thus, since there is large power consumption during the warm-up, the maximum power of the apparatus becoming large cannot be avoided. 
     SUMMARY 
     The aspects of the present invention are any one of the bookbinding apparatus or the image forming system described as follows. 
     1. A bookbinding apparatus for bookbinding a sheet with adhesive comprising: 
     an adhesive tank for storing adhesive; 
     a first heater for heating the adhesive; 
     a second heater for heating the adhesive; 
     a first adhesive temperature sensor for detecting temperature of the adhesive at a first position; 
     a second adhesive temperature sensor for detecting temperature of the adhesive at a second position that differs from the first position; 
     an agitation member for agitating the adhesive in the adhesive tank; and 
     a control device, 
     wherein the control device operates the agitation member after the first heater and the second heater are turned on, turns off the second heater and continues to have the first heater on after the second heater has been turned off when the second adhesive temperature sensor detects that adhesive temperature has reached a first temperature that is higher than an application temperature, and completes a warm-up when the first adhesive temperature sensor detects that adhesive temperature has reached the application temperature. 
     2. An image forming system comprising: 
     an image forming apparatus for forming an image on a sheet, and 
     a bookbinding apparatus according to item “1” for performing a bookbinding process on the sheet ejected from the image forming apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an entire configuration of an image forming system pertaining to an embodiment of the present invention. 
         FIG. 2  illustrates a configuration of a main section of a bookbinding apparatus pertaining to an embodiment of the present invention. 
         FIG. 3  illustrates a configuration of an adhesive application section. 
         FIG. 4  illustrates an arrangement of a roller heater. 
         FIG. 5  illustrates a block diagram of a control system for performing a heat control of adhesive in the bookbinding apparatus pertaining to an embodiment of the present invention. 
         FIG. 6  illustrates a flow chart of a heat control process. 
         FIG. 7   a  illustrates a graph indicating a temperature of the adhesive at the time of warm-up. 
         FIG. 7   b  illustrates a graph indicating a temperature of the adhesive at the time of warm-up. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereafter, the present invention will be described in reference to an embodiment. However, the present invention is not limited to the embodiment. 
       FIG. 1  illustrates an entire configuration of an image forming system related to an embodiment of the present invention. 
     An image forming system illustrated in the embodiment includes an image forming apparatus “A” and a bookbinding apparatus “B”. In this embodiment, a booklet storage apparatus “C” for storing a booklet being a bound book is connected to a latter stage of the above mentioned bookbinding apparatus “B”. The booklet storage apparatus “C” conveys and loads a booklet S 3  ejected from the bookbinding apparatus “B” onto a cart  92 . 
     &lt;Image Forming Apparatus “A”&gt; 
     The image forming apparatus “A” forms an image according to an electrophotography process. The image forming apparatus “A” includes an image forming device in which a charging device  2 , an image exposure device  3 , a development device  4 , a transfer discharge device  5  and a cleaning device  6  are arranged in a periphery of a rotatable photoreceptor  1 . 
     With respect to the image forming device, after the charging device  2  has performed a uniform charge on the surface of the photoreceptor  1 , the image exposure device  3  uses a laser beam to perform an exposure scan and forms a latent image based on image data, and the development device  4  performs a reversal development of the latent image and forms a toner image on the surface of the photoreceptor  1 . 
     A sheet “S” sheet-fed from a sheet storage device  7 A is sent to a transfer position. After the transfer discharge device  5  has transferred the toner image onto the sheet “S” at the transfer position, an electric charge of the sheet “S” is eliminated. Then the sheet “S” is separated from the photoreceptor  1 . The conveyance device  7  conveys the sheet “S”. Further, the fixing device  8  performs a heat fixing process on the sheet “S”. Then the sheet “S” is ejected by the sheet ejection roller  7 C. 
     In case when the image formation is performed on both sides of the sheet “S”, a conveyance switching device  7 D conveys the sheet “S” onto which the fixing device has performed the heat fixing to a conveyance path branched from a normal sheet ejection path. The reverse conveyance device  7 E switches back the sheet “S” to reverse the front and back of the sheet “S”. Then the reverse conveyance device  7 E conveys the sheet “S” to the transfer position again. An image is formed on the backside of the sheet “S” at the transfer position. 
     The sheet “S” onto which the fixing device  8  has performed a fixing process and the image has been formed is ejected from the sheet ejection roller  7 C to outside the apparatus. The sheet “S” ejected from the sheet ejection roller  7 C is sent into the bookbinding apparatus “B”. 
     The cleaning device  6  removes the development agent remaining on the surface of the photoreceptor  1  after the image processing has been performed to prepare for the next image formation. 
     An operation display section  9  that includes an input device and a display device is arranged on the upper section of the image forming apparatus “A”. 
     &lt;Bookbinding Apparatus“B”&gt; 
     The bookbinding apparatus “B” will be described using  FIGS. 1 and 2 .  FIG. 2  illustrates a configuration of a main section of the bookbinding apparatus. 
     The bookbinding apparatus “B” is configured by a sheet conveyance section  10 , a sheet delivery section  20 , a sheet bundle storage section  30 , a sheet bundle conveyance section  40 , an adhesive application section  50 , a cover sheet feed section  60 , a cover sheet cutting section  70 , a cover sheet holding section  80  and an operation display section  90 . 
     The sheet “S” introduced to the sheet conveyance section  10  from the image forming apparatus “A” is conveyed to the sheet delivery section  20 , to the sheet bundle storage section  30  or to the cover sheet holding section  80  by a plurality of conveyance rollers and a conveyance path-switching gate. 
     In case when there is no specification for a bookbinding process, the conveyance path-switching gate is set to directly eject the sheet “S” ejected from the image forming apparatus “A” onto a delivery tray of the sheet delivery section  20 . 
     In case when there is a specification for the bookbinding process, the sheet conveyance section  10  conveys the sheet “S” onto which the image formation has been performed by the image forming apparatus to the sheet bundle storage section  30 . Then a plurality of sheets “S” is accumulated onto the sheet bundle storage section  30 . Thus, a sheet bundle S 1  is formed. 
     The sheet bundle conveyance section  40  conveys the sheet bundle S 1  to a predetermined position. Then the adhesive application section  50  applies adhesive on a spine Sa of the sheet bundle S 1 . 
     A cover sheet S 2  held by the cover sheet holding section  80  is pasted on the spine Sa of the sheet bundle S 1  onto which the adhesive has been applied. The cover sheet S 2  is folded along both edges of the spine Sa of the sheet bundle S 1 . Then a booklet S 3  is created. 
     The sheet bundle storage section  30  includes a sheet loading platen  35 , which is arranged in inclination, a sheet rear edge positioning member  36 , which is capable of moving, and an aligning member  37 , which aligns the sheet in the width direction. 
     The sheet, which has been ejected from the image forming apparatus “A” and sent in by the sheet conveyance section  10 , is sequentially placed on the sheet loading platen  35 . Then a plurality of the sheets forms the sheet bundle S 1 . 
     After the aligning has been performed, the sheet bundle S 1  loaded on the sheet loading platen  35  of the sheet bundle storage section  30  is grasped by a grasping device  41 . In case when the grasping device  41  grasps the sheet bundle S 1 , the drive of a drive device not illustrated moves the sheet rear edge positioning member  36  below the sheet loading platen  35 . Then the sheet rear edge positioning member  36  retracts. 
     After moving to a diagonally lower section illustrated with broken line, the grasping device  41 , which has grasped the sheet bundle S 1  rotates and holds the sheet bundle S 1  in upright state so that the spine Sa of the sheet bundle S 1  onto which the adhesive application process is performed is facing downward. Then the grasping device  41  stops at a predetermined position. 
     On the other hand, a sheet feed device  62  separates and feeds the cover sheet S 2  stored in a cover sheet loading device  61  of the cover sheet feed section  60 . Then conveyance rollers  63 ,  64  and  65  convey the cover sheet S 2 . Further, conveyance rollers  81  and  82  of the cover sheet holding section  80  conveys the cover sheet S 2 . Then the cover sheet S 2  is stopped at a predetermined position. 
     In case when the length of the sheet cover S 2  is longer than a necessary length at the time of performing a wrap bookbinding process to the sheet bundle S 1 , the cover sheet cutting section  70  arranged on the right hand side of the conveyance roller  65  performs a cutting of the cover sheet S 2  so that an excessive portion of the cover sheet S 2  is removed in advance. 
     An adhesive tank  53  is arranged on a moving body  54  held by a cylindrical guide  55 . The adhesive tank  53  moves in the direction that is perpendicular to the sheet surface of  FIG. 2 . The home position of the moving body  54  is at the far side of the bookbinding apparatus. The moving body  54  moves to the near side of the bookbinding apparatus at the time of application. 
     An application roller  51  moves along the spine Sa of the sheet bundle S 1  in the direction perpendicular to the sheet surface of  FIG. 2  by the drive of a motor M and a drive system  52 . 
     The cover sheet holding section  80  moves up and down by an ascending descending device  86 . 
     After the moving body  54  has moved to the near side of the bookbinding apparatus from the home position, the application roller  51  moves back and forth in the direction of arrows W 2  and W 3  (described later, refer to  FIG. 3 ) by the drive of the motor M. Then the adhesive is applied to the spine Sa of the sheet bundle S 1 . 
     After the application is complete, the moving body  54  returns to the home position. Then the cover sheet holding section  80  ascends and pastes the cover sheet S 2  on the spine Sa. “ 83 ” is a pressing member for pasting the cover sheet S 2  onto the spine Sa securely. 
     The booklet S 3  is created by pasting the cover sheet S 2  on the sheet bundle S 1 . Then the booklet S 3  is conveyed by a belt  87  and is ejected to the booklet storage apparatus “C”. 
     &lt;Adhesive Application Section&gt; 
       FIG. 3  illustrates the adhesive application section  50 . 
     The adhesive application section  50  includes the adhesive tank  53  for storing adhesive N that has been melted and liquefied, an application roller  51  as an agitation member that agitates the adhesive N, a regulating member  503 , a regulating member  504 , a tank heater H 1  being a first heater for heating the adhesive, a roller heater H 2  being a second heater for heating the adhesive, an adhesive temperature sensor TS 1  being a first temperature sensor for detecting temperature of the adhesive in the adhesive tank and a remaining amount sensor  506 . 
     The agitation member for agitating the adhesive is configured by the application roller  51  in the embodiment illustrated. However, an adhesive application member and an agitation member may be configured separately. 
     As illustrated, the tank heater H 1  is arranged at the bottom section of the adhesive tank  53 . Then the tank heater H 1  heats the entire adhesive tank  53 . 
     As illustrated in  FIG. 4 , the roller heater H 2  heats a shaft  51 A of the application roller  51 . The shaft  51 A is structured by metal. The heat of the shaft  51 A heats the entire application roller  51 . Then the adhesive on the application roller  51  is heated. 
     A supplying device delivers the adhesive N in a pellet state into the adhesive tank  53 . 
     The adhesive in the pellet state is heated and melted. Then the adhesive in the pellet state becomes the adhesive N that is liquefied. 
     The adhesive is delivered from the supplying device corresponding to a detection signal of the remaining quantity-sensor  506  so that the surface of the adhesive N is maintained at a fixed level. 
     “ 503 ” is a cylindrical regulating member whose cross-section is nearly circular. “ 504 ” is a regulating member. “ 504 ” is fixed by having the both ends of a non-application area screwed onto a plate-shaped holding member  507 . 
     The regulating member  504  includes a main scraping section  504 A and an auxiliary scraping section  504 C. The regulating member  504  is a device for scraping the adhesive so that the adhesive applied onto the spine of the sheet bundle S 1  by the application roller  51  becomes a predetermined thickness. 
     “ 504 D” is a regulating member for regulating an adhesive layer thickness on the application roller  51 . 
     The regulating member  503  is arranged on an opposite side of the above mentioned regulating member  504  having the application roller  51  between the regulating member  503  and the regulating member  504 . The regulating member  503  is a cylindrical bar shaped member for regulating the application thickness of the adhesive. 
     The application roller  51  applies the adhesive on the spine Sa of the sheet bundle by having the drive of the motor M (refer to  FIG. 2 ) move the application roller  51  back and forth along the spine Sa of the sheet bundle in the direction indicated with the arrows W 2  and W 3  while having the drive of a motor not illustrated rotate the application roller  51  in the direction indicated with the arrow W 1 . 
     At the time of a forward movement (in the direction of W 2 ), mainly the regulating member  503  regulates the application amount of the adhesive N. At the time of a backward movement (in the direction of W 3 ), mainly the regulating member  504  regulates the application amount of the adhesive. These regulations form an even adhesive layer on the spine Sa of the sheet bundle. 
     &lt;Control at the Time of the Warm-Up&gt; 
     A warm-up time for the adhesive application section  50 , namely, from the time when the tank heater H 1  is turned on to the time when the adhesive is melted to a state that the adhesive is applicable, requires several minutes to ten minutes. 
     Shortening of a wait time and improving work efficiency are one of the important technical objects in the development of a bookbinding apparatus. 
     In the present invention, the warm-up time has been shortened by using a plurality of heaters and heating the adhesive up to the first temperature that is higher than the above mentioned application temperature with the second heater in the process of heating the adhesive up to an application temperature with the first heater. 
     The above mentioned first temperature is higher than the application temperature. It is preferable that the temperature of the first temperature to be at the maximum temperature that does not deteriorate the adhesive. 
       FIG. 5  illustrates a block diagram of a control system for performing a heat control of the adhesive in the bookbinding apparatus pertaining to an embodiment of the present invention.  FIG. 6  illustrates a flow chart of a first example of a heat control process. 
     A control device CR controls ON and OFF of the tank heater H 1  and the roller heater H 2  based on an output of a adhesive temperature sensor TS 1  being a first adhesive temperature sensor for detecting the temperature of the adhesive in the adhesive tank  53  and on an output of a adhesive temperature sensor TS 2  being a second adhesive temperature sensor for detecting the temperature of the adhesive on the application roller  51 . 
     As illustrated in  FIG. 3 , the adhesive temperature sensor TS 1  contacts the adhesive N and detects the adhesive temperature. The adhesive temperature sensor TS 2  is arranged inside the application roller  51 . The adhesive temperature sensor TS 2  indirectly detects the temperature of the adhesive on the application roller  51  by detecting the temperature of the application roller  51 . 
     In STEP ST 1 , the tank heater H 1  and the roller heater H 2  are turned on. Then the heating starts. 
     In STEP ST 2 , whether a detection temperature of the adhesive temperature sensor TS 1  has reached to a melting point (for example, 90 degrees Celsius) of the adhesive N being the second temperature that is lower than the application temperature is monitored. In case when the detection temperature of the adhesive temperature sensor TS 1  has reached the second temperature, a rotation control of the application roller  51  starts in STEP TS 3 . 
     The starting time of the rotation control of the application roller  51  may be set to a prescribed period of time after the heater has been turned on in STEP ST 1 . This prescribed period of time can be determined from an experimental result of the experiment conducted in advance for measuring the time from when the heater turned on to when the adhesive temperature has reached the melting point. 
     When the application roller  51  is attempted to rotate before the adhesive temperature reaches the melting point, a large load is put on the motor being the drive source of the roller. This leads to a corruption of the motor. Thus, the application roller  51  rotates smoothly in the liquefied adhesive N by having the application roller  51  stopped until the adhesive temperature reaches the melting point and having the application roller  51  rotate after the adhesive temperature has reached to the melting point. 
     The rotation control of ST 3  is an intermittent drive control that repeats a rotation and a stop of the application roller  51  at an interval of two to three seconds. 
     The rotation control of ST 3  agitates the adhesive N well so that the adhesive N in the adhesive tank  53  is quickly and uniformly heated. In particular, the adhesive on the application roller  51  and the adhesive N in the adhesive tank  53  are mixed. 
     In STEP ST 4  following STEP ST 3 , the adhesive temperature sensor TS 2  monitors whether the temperature of the application roller  51  has reached the maximum temperature or not. In case when the temperature of the application roller  51  has reached the maximum temperature, the roller heater H 2  is turned off. 
     The maximum temperature of the application roller  51  is the maximum temperature in which the adhesive N does not deteriorate. For example, the maximum temperature may be set to 185 degrees Celsius. 
     In case when the roller temperature has reached the maximum temperature (Yes on ST 4 ), the roller heater H 2  is turned off (ST 5 ). The tank heater H 1  continues to be power on even when the roller heater H 2  is turned off. 
     In the following STEP ST 6 , whether the detection temperature of the adhesive temperature sensor TS 1  has reached the application temperature or not is monitored. 
     For example, the application temperature may be set to 165 degrees Celsius. 
     As a result of the temperature monitoring in STEP ST 6 , in case when the temperature of the adhesive N in the adhesive tank  53  has reached the application temperature, the warm-up completes. 
     Although not illustrated in  FIG. 6 , the roller heater. H 2  is turned off after the completion of the warm-up. Then the on and off of the tank heater H 1  is controlled to maintain the temperature of the adhesive N in the adhesive tank  53  to the application temperature. 
     The change in the adhesive temperature during the warm-up is illustrated in  FIG. 7 . 
       FIG. 7  ( a ) illustrates the change in the adhesive temperature in the conventional control.  FIG. 7   b  illustrates the change in the adhesive temperature in the control pertaining to an embodiment of the present invention. 
     The conventional control will be described first. 
     Conventionally, the application roller  51  had been stopped during the warm-up. The tank heater H 1  and the roller heater H 2  have also been used in conventional control. 
     In  FIG. 7   a , at time to, the tank heater H 1  and the roller heater H 2  are turned on, and the heating starts. 
     Since the adhesive on the application roller  51  is heated by the tank heater H 1  and the roller heater H 2 , the rising rate of the temperature of the adhesive on the roller is higher than the rising rate of the temperature of the adhesive in the adhesive tank  53 . Thus, as indicated by a curved line L 1 , the temperature of the adhesive on the application roller linearly and abruptly rises. 
     At time t 1  when the temperature of the adhesive on the application roller  51  has reached the application temperature u 0 , the roller heater H 2  changes from a continuously turned on state to a turned on and off state. The temperature of the adhesive on the application roller  51  is maintained at the application temperature u 0  by the on and off control after the time t 1 . 
     On the other hand, as a curved line L 2  indicates, the temperature of the adhesive in the adhesive tank  53  moderately rises. Then the temperature of the adhesive in the adhesive tank  53  reaches to the application temperature u 0  at time t 2 . 
     After time t 2 , the on and off control is performed on the tank heater H 1 . Thus, the temperature of the adhesive in the adhesive tank  53  is maintained at the application temperature u 0 . 
     In  FIG. 7   b , at time t 0 , the tank heater H 1  and the roller heater H 2  are turned on. Then the heating starts. 
     Since the temperature of the adhesive on the application roller  51  is heated by the tank heater H 1  and the roller heater H 2 , the rising rate of the temperature of the adhesive on the application roller  51  is higher than the rising rate of the temperature of the adhesive in the adhesive tank  53 . Thus, as indicated by a curved line L 3 , the temperature of the adhesive on the application roller linearly and abruptly rises. 
     The roller heater H 2  is turned off at time t 11  when the temperature of the adhesive on the application roller  51  has reached the maximum temperature u 1 . 
     On the other hand, just as an initial straight line section L 4   a  of a curved line L 4 , the temperature of the adhesive in the adhesive tank  53  moderately rises. The temperature of the adhesive in the adhesive tank  53  reaches to the adhesive melting point u 2  at time t 10 . 
     At time t 10  when the temperature of the adhesive in the tank has reached the melting point u 2 , the rotation control of the application roller  51  is started. That is, the application roller  51  repeats rotation and stop to agitate the adhesive N. 
     The rising rate of the temperature of the adhesive in the tank increases by the agitation of the adhesive N just as indicated by the straight line section L 4   b  of the curved line L 4 . 
     As curved lines L 3  and L 4  indicate, time t 11  when the temperature of the adhesive on the application roller  51  reaches the maximum temperature elapses faster than the time that the temperature of the adhesive N in the adhesive tank  53  reaches to the application temperature. Therefore, as illustrated, the tank heater H 1  continues heat even after the roller heater H 2  has been turned off. Thus the temperature of the adhesive continues to rise. 
     After time t 12  when the temperature of the adhesive N in the adhesive tank  53  has reached the application temperature u 0 , the on and off control is performed on the tank heater H 1  and the temperature of the adhesive in the adhesive tank  53  is maintained at the application temperature u 0 . 
     As illustrated in  FIG. 6 , the warm-up is complete when the adhesive temperature sensor TS 1  detects that the temperature of the adhesive N in the adhesive tank  53  reaches the application temperature. 
     In the embodiment of the present invention of  FIG. 7   b , the warm-up is completed at time t 12  that is approximately 10 minutes after the warm-up has started. 
     On the other hand, in the conventional example illustrated in  FIG. 7   a , the warm-up time is 15 minutes. 
     The rotation of application roller  51  contributes to shortening the warm-up time illustrated in  FIG. 7   b . However, the warm-up time can be shortened also by having the roller heater H 2  heats the adhesive on the application roller to the maximum temperature that is higher than the application temperature, and by having the rotation of the application roller  51  mix the high temperature adhesive with the adhesive N in the adhesive tank  53  so that the rising rate of the temperature of the adhesive becomes high. 
     Thus, the warm-up time is significantly shortened by the present invention. 
     In the embodiment illustrated in  FIGS. 6 and 7 , the adhesive N in the adhesive tank  53  and the adhesive on the application roller  51  are mixed by having the application roller  51  being an adhesive supplying member rotate when the temperature of the adhesive N reaches the melting point. 
     However, it is also possible to perform the following control. 
     The tank heater H 1  and the roller heater H 2  are turned on and the warm-up is started. In case when the adhesive temperature sensor TS 2  detects the maximum temperature, the roller heater H 2  is turned off. 
     On the other hand, the tank heater H 1  continues to be on. The tank heater H 1  is turned off when the adhesive temperature sensor TS 1  detects that the temperature of the adhesive N in the adhesive tank  53  has reached the temperature that is slightly lower than the application temperature. The adhesive N is agitated by the rotation of the application roller  51 . Then the warm-up completes. 
     When the high temperature adhesive on the application roller  51  is mixed with the adhesive N, the temperature of the adhesive N rises and reaches to the application temperature. 
     In the image forming system, the wait time of the image forming apparatus “A” is shorter than the wait time of the bookbinding apparatus “B”. Therefore, the bookbinding apparatus “B” influences the work efficiency of the entire image forming system. The present invention shortens the wait time of the bookbinding apparatus “B” and the work efficiency of the image forming system is remarkably improved.