Abstract:
When a sheet is brought into a sheet storage section ( 12 ), a fan  126  creates an air current towards the sheet storage part ( 12 ), and when the sheet is discharged from the sheet storage section ( 12 ), the fan stops air blow. Whereby, the conveyance of the sheet to the sheet storage section ( 12 ) is guided, and discharging of the sheet from the sheet storage section is smoothly carried out.

Description:
TECHNICAL FIELD 
     The present invention relates to an intermediary conveyance device and an image forming system including the intermediary conveyance device. 
     PRIOR ART 
     In operation to convey a sheet and stack a plurality of the sheets, when a sheet conveyed subsequently (a successive sheet) is stacked on a sheet (a precedent sheet) conveyed and stacked in advance, there is a problem that the successive sheet contacts with the precedent sheet and alignment of a plurality of sheets stacked is disturbed. 
     In the Patent Document 1(Japanese Patent No. 2931447), in order to solve the above problem, a laminar air is flowing between an obverse surface of the sheet stacked on the sheet discharging table and a reverse surface of the sheet to be subsequently discharged.
     Patent Document 1: Japanese Patent No. 2931447   

     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
     According to the conveyance and sheet discharging method disclosed in Patent Document 1, misalignment due to contact between the sheet stacked in advance and the sheet subsequently discharged is obviated. 
     However, in case the conveyance and sheet discharging method described in the Patent document 1 is applied to an intermediary conveyance device which receives a sheet from a processing apparatus in an upstream side and discharge the sheet towards a processing apparatus in a downstream side, there are problems described as follow. 
     In the intermediary conveyance device the sheet has to be delivered from the apparatus in the upstream side and discharged to the apparatus in the downstream side. When the sheet is brought into the sheet storing section of the intermediary conveyance device, it is effective that the sheet is guided by an air current so as to convey the sheet smoothly. 
     However, in the intermediary conveyance device, since the sheet is discharged towards the processing apparatus in the downstream side, there is a case that the aforesaid air current affects discharging of the sheet, and the sheet cannot be discharged smoothly. 
     Also, in case the intermediary conveyance apparatus having the sheet aligning device performs the aligning process inside the intermediary conveyance apparatus and conveys the sheet to the processing apparatus in downstream side, the aligning process is disturbed by the aforesaid air current. 
     The present invention has one aspect to solve the above problems in the intermediary conveyance apparatus. 
     Means to Resolved the Problem 
     An object of the present invention is achieved by the following. 
     Item 1: An intermediary conveyance apparatus having a sheet storing section to store a sheet, a sheet entering section to convey the sheet to the sheet storing section and a sheet discharging section to discharge the sheet stored in the sheet storing section, including: a blower device to blow air to the sheet storing section; and an intermediary conveyance control device to control the blower device, wherein the intermediary conveyance control device controls the blower device to blow air to the sheet storing section when the sheet is conveyed from the sheet entering section to the sheet storing section, and to stop air blow to the sheet storing section when the sheet is discharged from the sheet storing section via the sheet discharging section.
 
Item 2: An intermediary conveyance apparatus having a sheet storing section to store a sheet, a sheet entering section to convey the sheet to the sheet storing section and a sheet discharging section to discharge the sheet stored in the sheet storing section, including: a blower device to blow air to the sheet storing section; a sheet aligning device to align the sheet stored in the sheet storing section; and an intermediary conveyance control device to control the blower device and the sheet aligning device,
 
     wherein the intermediary conveyance control device controls the aligning device and the blower device to blow air to the sheet storing section when the sheet is conveyed from the sheet entering section to the sheet storing section, and to stop air blow to the sheet storing section when an aligning process by the sheet aligning device is completed. 
     Item 3: The intermediary conveyance apparatus of item 1, wherein the sheet aligning device performs longitudinal aligning. 
     Item 4: The intermediary conveyance apparatus of any one of items 1 to 3, wherein the sheet storing section stores a plurality of the sheets. 
     Item 5: The intermediary conveyance apparatus of any one of items 1 to 4, wherein the intermediary conveyance control device control the blower section to blow air to the sheet storing section when the plurality of the sheets are stored in the sheet storing section and to stop air blow when the plurality of the sheets are not stored in the sheet storing section.
 
Item 6: The intermediary conveyance apparatus of any one of items 1 to 5, wherein the sheet storing section reverses the sheet in a way that a conveyance direction of the sheet when the sheet is conveyed from the sheet entering section opposes a conveyance direction of the sheet when the sheet is discharged from the sheet discharging section.
 
Item 7: The intermediary conveyance apparatus of any one of items 1 to 6, wherein the intermediary conveyance control section controls the blower device based on a sheet detection signal of a sensor provided at the sheet entering section.
 
Item 8: The intermediary conveyance apparatus of any one of items 1 to 7, wherein the blower device includes a restriction member to restrict an air current, wherein the intermediary conveyance control device controls the restriction member so as to start and stop air blow to the sheet storing section.
 
Item 9: The intermediary conveyance apparatus of any one of items 1 to 8, wherein the sheet storing section stores the sheet in a vertical state and the blower device is provided with a fan disposed above the sheet storing section.
 
Item 10: The intermediary conveyance apparatus of item 9, further comprising: a conveyance path to convey the sheet from the sheet entering section to the sheet discharging section without passing through the sheet storing section, and a guide member configuring the conveyance path is provided with a hole through which the air current from the fan goes.
 
Item 11: The intermediary conveyance apparatus of any one of items 1 to 10, wherein the sheet conveyance section is provided with a guide member for restriction to move the sheet stored in the sheet storing section to a sheet discharging side.
 
Item 12: An image forming system, having an image forming apparatus, the intermediary conveyance apparatus of any one of items 1 to 11, and a post-processing apparatus, to convey the sheet from the image forming apparatus to the post processing apparatus via the intermediary conveyance apparatus, wherein the image forming apparatus includes a linear sheet discharging function, a reversal sheet discharging function and a main control device, the intermediary conveyance apparatus includes a linear conveyance function and a reversal conveyance function, the main control device selects the linear sheet discharging function or the reversal sheet discharging function, and the intermediary conveyance control apparatus selects and uses the linear conveyance function or the reversal conveyance function based on information acquired from the main control device.
 
Item 13: The image forming system of item 12, wherein the intermediary conveyance control device selects the linear conveyance function or the reversal conveyance function based on at least one item of information from the main control device regarding image forming mode in the image forming apparatus, a size of the sheet, a kind of the sheet, an environment and post-processing in the post-processing apparatus.
 
     Effect of the Invention 
     According to the present invention, when the sheet is brought into the sheet storing section, since the sheet is guided by the air current towards the sheet storing section generated by a blower, the sheet is conveyed to the sheet storing section smoothly. 
     When the sheet is conveyed form the sheet storing section to the sheet conveyance section, since the air blast ceases the sheet is discharged smoothly. 
     As a result, conveyance and discharge of the sheet in the intermediary conveyance device is carried out smoothly, high speed conveyance is possible irrespective of size and kind of the sheet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an entire structure of the image forming system related to an embodiment of the present invention. 
         FIG. 2  is an explanatory diagram of the conveyance path when an intermediary conveyance apparatus B is viewed from a perpendicular direction with respect to a conveyance direction. 
         FIG. 3  is an explanatory diagram of a fan and a conveyance path when an intermediary conveyance apparatus B is viewed from a perpendicular direction with respect to a conveyance direction. 
         FIG. 4  is a front cross-sectional view of the intermediary conveyance apparatus B. 
         FIG. 5  is a front cross-sectional view of the intermediary conveyance apparatus B. 
         FIG. 6  is a front cross-sectional view of the intermediary conveyance apparatus B. 
         FIG. 7  is a front cross-sectional view of the intermediary conveyance apparatus B. 
         FIG. 8  is a front cross-sectional view of the intermediary conveyance apparatus B. 
         FIG. 9  is a front cross-sectional view of the intermediary conveyance apparatus B. 
         FIG. 10  is a front cross-sectional view of the intermediary conveyance apparatus B. 
         FIG. 11  is a front cross-sectional view of the intermediary conveyance apparatus B. 
         FIG. 12  is a block section of a control system of the intermediary conveyance apparatus B. 
         FIG. 13  is a timing chart of an operation of the intermediary conveyance apparatus B. 
     
    
    
     DESCRIPTION OF THE SYMBOLS 
     
         
           11  Sheet entering section 
           12  Sheet storing section 
           13  Sheet detection section 
           123  Sheet stopper 
         R 1 , R 2 , R 6  and R 7  Roller pairs 
         R 3 , R 4  and R 5  Rollers 
         G 1 , G 2 , G 3 , G 4 , G 5  and G 6  Guide sections 
           9 A Main control device 
           9 B Intermediary conveyance control device 
         SE Sensor 
       
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will be described with reference to the drawings without the present invention being restricted by the drawings thereof. 
       FIG. 1  is an entire structure of an image forming system related to an embodiment of the present invention. 
     [Image Forming System] 
     An image forming apparatus A shown by the figure is provided with an image reading section  1 , an image processing section  2 , an image writing section  3 , an image forming section  4 , a sheet conveyance device  5  and a fixing device  6 . 
     The image forming section  4  is configured with a photoconductive drum  4 A, a charging device  4 B, a developing device  4 C, a transfer device  4 D and a separation device  4 E and a cleaning device  4 F. 
     The sheet conveyance device  5  is provided with a sheet feeding cassette  5 A, a first sheet feeding device  5 B, a second sheet feeding device  5 C, a conveyance device  5 D, a sheet discharging device  5 E and an automatic duplexing unit (ADU)  5 F. 
     On a front side of an upper section of the image forming apparatus A, an operation display device  8  configured with an input device and a display device is disposed. At the upper section of the image forming apparatus A, an automatic document feeding apparatus DF is disposed. At a sheet discharging device  5 E side i.e. left side surface of the image forming apparatus A in the figure, an intermediary conveyance apparatus B is connected and a post-processing apparatus FS is further connected at a left side thereof. 
     A document is placed on the document table of the automatic document feeding apparatus DF and images of the document on one side or both sides are read via an optical system of the image reading section  1 . An analogue signal having been subject to photoelectric conversion is sent to the image writing section  3  after processing such as analogue processing, A/D conversion, shading correction and image compression in the image processing section  2 . 
     In the image writing section  3 , the photoconductive drum  4 A of the image forming section  4  is irradiated with an output light from a semiconductor laser so as to form a latent image. In the image forming section  4 , processing such as charging, exposing developing, transferring, separating and cleaning are conducted. 
     On a sheet S fed from a first sheet feeding device  5 B, an image is transferred via a transfer device  4 D. The sheet S carrying the image is fixed via the fixing device  6  and conveyed to the intermediary conveyance apparatus B from the sheet discharging device  5 E. Or, a sheet S after being subject to one side image processing conveyed to the automatic duplexing unit (ADU)  5 F is subject to both side image processing in the image forming section  4 , after that the sheets is discharged via the sheet discharging device  5 E and conveyed to the intermediary conveyance apparatus  13 . 
     A main control device  9 A disposed in the image forming apparatus A and the intermediary conveyance control device  9 B disposed in the intermediary conveyance apparatus B are connected with a communication circuitry  9 C to transmit and receive a input signal and a control signal. 
     A large capacity sheet feeding apparatus LT configured with a sheet stacking device  7 A and a first sheet feeding device  7 B conveys a large amount of the sheets S and sent to the image forming apparatus A. 
     Meanwhile, the large capacity sheet feeding apparatus LT can be connected with the intermediary conveyance apparatus B to be described, so that a large amount of the sheet S stored in the large capacity sheet feeding apparatus LT can be sent to the intermediary conveyance apparatus B directly. 
     In the intermediary conveyance apparatus B is a conveyance device to pass the sheets from the image forming apparatus A to the post-processing apparatus FS without reducing the productivity of the entire system in case a difference of processing ability exists between the image forming apparatus A and the post-processing apparatus. 
     The post-processing apparatus FS is provided with a conveyance section  20  to convey the sheet S and a coversheet K discharged from the intermediary conveyance apparatus B, a folding section  21  to perform folding such as double folding and triple folding for the sheet S and the coversheet K and a sheet discharging tray  22  to which a small amount of the sheets S are discharged and an sheet discharging tray  23  to which a large amount of the sheets S and the coversheet K are discharged. 
     A numeral  24  denoted a sheet feeding tray to supply the coversheet K to be added to the sheet S discharged from the image forming apparatus A. 
     The sheet S conveyed from the image forming apparatus A to the post-processing apparatus FS via the intermediary conveyance apparatus B is conveyed horizontally, and discharged to sheet discharging trays  22  and  23  without being processed. 
     Or, the sheet S conveyed to the post-processing apparatus FS is conveyed to the folding section  21  and after folding processing via folding section  21 , the sheet S is discharged to the sheet discharging tray  23 . 
     Further, in the same manner, the coversheet K fed from the sheet feeding tray  24  is discharged to the sheet discharging try  23  with or without having been subject to folding process. 
     In the embodiment in the figure, the post-processing apparatus FS performs folding processing, and the post-processing apparatus having functions to perform various kinds of processing can be connected after the intermediary conveyance apparatus B. 
     Also, a plurality of the conveyance apparatus can be connected after the intermediary conveyance apparatus B. 
     As the post-processing apparatus, one having one or more functions such as a perforation processing, stapling processing, and book binding processing can be connected at the downstream sided of the intermediary conveyance apparatus B. 
       FIGS. 2 and 3  show main structures of the intermediary conveyance apparatus B related to the embodiment of the present invention.  FIG. 2  is an explanatory diagram of the conveyance path when viewing the intermediary conveyance apparatus B from a direction perpendicular to the conveyance path, and  FIG. 3  is an explanatory diagram of a fan and a conveyance path when viewing the intermediary conveyance apparatus from a conveyance direction. 
     &lt;Structure of Intermediary Conveyance Apparatus B&gt; 
     The intermediary conveyance apparatus B is provided with a sheet entering section  11 , sheet storing section  12  and sheet discharging section  13  ( FIG. 1 ). 
     As  FIG. 2  shows, the sheet entering section  11  receives and conveys the sheet discharged form the image forming apparatus A and the sheet storing section  12  to receive the sheet from the sheet entering section  11  and reverse a conveyance direction can store a plurality of the sheets. The sheet discharging section  13  discharges the sheet whose conveyance direction is reversed via the sheet storing section  12 . 
     The intermediary conveyance apparatus B has a conveyance mode in which the sheet from the sheet entering section  11  is discharged from the sheet discharging section  13  via the sheet storing section  12  and a conveyance mode in which the sheet is conveyed from the sheet conveyance section  11  to the sheet discharging section  13  and discharged from the sheet discharging section  13 . 
     As  FIG. 2  shows, the sheet entering section  11  is provided with a roller pair R 1 , a roller pair R 2 , a roller R 3 , and guide members  120 , G 1 , G 2  and G 3 . The guide member  120  is a fixed guide member to guide the sheet horizontally, and the guide members G 1  and G 2  are a guide member to guide the sheet from a horizontal state to a vertical state. The guide member G 1  is a stationary guide member. 
     The guide member G 2 , the roller R 4  and the guide member G 5  configure an integral rotatable block centering around an axis X 1 , and the block is driven by a solenoid SOL 2  (refer to  FIG. 12 ) to rotate. 
     The guide members G 2  and G 5  guide the sheet and configure a restriction member to restrict a direction of an air current generated by a fan  126 . 
     The roller R 4  in contact with and rotated by the roller R 5 , and the roller R 5  is driven by a motor M 2  to rotate. 
     The roller pairs R 1  and R 2  and the roller R 3  are driven by a motor M 1  (refer to  FIG. 12 ) to rotate. The roller R 3  is supported by an unillustrated lever which rotates around an axis of a lower roller of the roller pair R 2  and displaced by rotation of the lever driven by the solenoid SOL  1  (refer to  FIG. 12 ). 
     The roller R 4  is configured with four rollers R 4 A, R 4 B, R 4 C and R 4 D as  FIG. 3  shows. 
     The rollers R 4 B and R 4 C located in a center section in the width direction (a direction perpendicular to the sheet conveyance direction) are in contact with the roller R 3 , and the rollers R 4 A and R 4 D at both end sections are in contact with the roller R 5 . 
     The rollers R 3  and R 4  are disposed at an end of the downstream side of the conveyance path formed by the guide members G 1  and G 2 , and the guide member G 3  is disposed at a downstream side of the roller R 3 . 
     The guide member G 3  is rotatable around an axis X 2  and driven by a solenoid SOL 3  (refer to  FIG. 12 ) to rotate. 
     Meanwhile, the meanings of the upstream and downstream sides are based on the sheet conveyance direction. 
     The sheet storing section  12  is provided with a pair of stationary sheet retaining boards  121  being parallel each other and extending in a vertical direction, a width aligning device  122  and a sheet stopper  123 . 
     In the sheet entering section  11 , the front end of the sheet conveyed comes to contact with the sheet stopper  123  and stops, and then the sheet is held in a vertical state with the sheet holding board  121 . 
     The sheet aligning device  122  is a device to align the sheet in the width direction. The sheet aligning device  122  is driven by a motor M 3  (refer to  FIG. 12 ) to be reciprocated in the width direction of the sheet so as to bookend the sheet. 
     The sheet stopper  123  being guided by a vertical guide bar  124  is driven by a motor M 4  (refer to  FIG. 12 ) and the belt  125  so as to move up and down. 
     The stopper  123  moves up and down in accordance with the size of the sheet besides it moves in a sheet conveyance process to be described. 
     The sheet discharging section  13  is provided with a pair of guide members  120  representing a stationary guide member, a fixed guide member G 4 , movable guide members G 5 , G 6 , a roller R 5  and roller pairs R 6  and R 7 . The guide member G 6  moves while being supported by an unillustrated lever which is driven by the solenoid SOL 4  (refer to  FIG. 12 ) so as to rotate around the axis X 3 . 
     A numeral  126  denotes a fan to send the air current to the sheet entering port section of the sheet storing section  12 . 
     The fan  126  is configured with two fans  126 A and  126  B disposed in parallel in the width direction as  FIG. 3  shows. The two fans  126 A and  126 B generate an even air flow in the width direction. 
     At the guide member  120  configuring the conveyance path, multiple openings (holes)  12 A are disposed in a uniform distribution in the width direction as  FIG. 3  shows, and an air flow from the fan  126  flows to a downstream side via the openings  120 A. 
     A numeral  127  denotes a changeover gate driven by a solenoid SOL 5  (refer to  FIG. 12 ) to change whether the sheet is conveyed horizontally or conveyed to the sheet storing section  12 . 
     A numeral  128  denotes a longitudinal aligning board driven by a solenoid SOL 4  (refer to  FIG. 12 ) to restrict an upper end of the sheet to be. The guide member G 6  and the longitudinal aligning board  128  are configured with an integral member. When the solenoid SOL  4  is turned off, the longitudinal aligning board appears in the sheet conveyance path so as to stop the upper end of the sheet to be conveyed. 
     When the solenoid SOL 4  turns on, the longitudinal aligning board  128  is retracted from the sheet conveyance path, and the guide member G 6  rotates around the axis X 3  so as to open the space between the opposing guide member G 4  and forms the sheet conveyance path. 
     &lt;Operation of Intermediary Conveyance Apparatus&gt; 
     An operation of the intermediary conveyance apparatus B will be described with reference to  FIGS. 4 to 13 . 
       FIGS. 4 to 11  are cross-sectional views of the intermediary conveyance apparatus B showing stages  1  to  8  in the operation to convey the sheet. 
       FIG. 12  is a block diagram of a control system of the intermediary conveyance apparatus B, and  FIG. 13  shows a timing chart of the operation of the intermediary conveyance apparatus B. 
     An intermediary conveyance control device  9 B disposed in the intermediary conveyance apparatus B conducts control operation shown in  FIG. 13  based on information from a main control device  9 A disposed in the image forming apparatus A and a sheet detection signal of a sensor SE disposed at the sheet entering section  11 . 
     A starting timing of each section in  FIG. 13  is determined by sheet detection signal of the sensor SE. 
     In  FIG. 13 , to perform discharging drive, the motor M 2  operates to drive the roller R 5  to perform stopping member drive, stop member drive and to perform longitudinal aligning board drive, the solenoid SOL  4  operates to retract the longitudinal aligning board  128  from a aligning position 
     In  FIG. 13 , the stopping member drive is described by operation of the motor M 4  i.e. obverse rotation, reverse rotation and stop, and in an initial sate, the sheet stopper  123  is at a height shown in  FIG. 4 . 
     After the motor M 4  performs an operation shown by “ascent”, the sheet stopper  123  is set at an ascended height, and after the motor M 4  performs an operation shown by “descent” the sheet stopper  123  is set at a descended height. 
     The blower device is configured with the fan  126  and the guide members G 2  and G 5  representing restriction members to restrict a direction of the air current. Operation of the blower device includes operating the solenoid SOL 2 , displacing the guide members G 2  and G 5 , and changing the air current from a direction W 1  to a direction W 2 . 
     Longitudinal aligning is an aligning process to align the sheet in the conveyance direction. The longitudinal aligning board drive is indicated by on and off of the solenoid SOL 4  to drive the longitudinal aligning board  128 . 
     As described above, while the solenoid SOL 4  is on, the longitudinal aligning board  128  is retracted from the sheet conveyance path. 
     Longitudinal aligning is performed by ascending the sheet stopper  123  while the longitudinal aligning board appears in the sheet conveyance path so as to contact the upper end of the sheet with the longitudinal aligning board  128 . Incidentally, the sheet aligning device in the present embodiment is configured with the longitudinal aligning board  128 , the solenoid SOL 4 , the sheet stepper  123 , the motor M 4 , the width aligning device  122  and the motor M 3 . 
     In  FIG. 13 , ascent of the sheet stopper  123  between stages  5  and  6  shows a longitudinal aligning process. 
     As  FIG. 13  shows, longitudinal aligning is performed while the blower device is stopped. Further specifically, the blower device is stopped until aligning is completed. 
     Numerals  1  to  8  in  FIG. 13  correspond to stages  1  to  8  shown by  FIGS. 3 to 10 . 
     In the sheet conveyance process of the intermediary conveyance apparatus B to be described, the fan  126  operates continuously and the air current is switched between the direction W 1  to guide conveyance of the sheet and the direction W 2  not to guide conveyance of the sheet and not to disturb aligning of the sheet and discharging of the sheet from the sheet storing section  12 . 
     Incidentally, the blower device in  FIG. 13  can be turned on and off by tuning on and off the fan  12 , instead of changing the directions of the air current by the air current restriction device (guide members G 2  and G 5 ) as the embodiment. 
     The air current flowing in the direction shown by W 1  conveys the sheet smoothly in the entering port section of the sheet storing section  12  and the sheet storing section  12 , and the lower end of the sheet reaches to the sheet stopper  123  unfailingly. 
     The roller pairs R 1  and R 2  and the roller R 3  continuously rotates by driving the motor M 1 . 
     As  FIG. 4  shows, the first sheet S 1  discharged form the image forming apparatus A is conveyed horizontally via the roller pairs R 1  and R 2  to the sheet conveyance section  11  and detected by the sensor SE (stage  1 ). 
     At a sheet entering step showing in  FIG. 4 , the rollers R 3 , R 4  and R 5  are in contact each other and the roller pairs R 1  and R 2  and the roller R 3  is driven by the motor M 1  to rotate so as to convey the sheet S 1 . 
     In a sheet entering stage, the air current from the fan  126  flows downward as a wave shaped arrow W 1  shows so that a resistance of the guide member with respect to the sheet S 1  is reduced. 
     In a process of conveyance of the sheet S 1  from the sheet entering section  11  to the sheet storing section  12 , falling of the sheet S 1  may be interrupted by a resistance due to frictions of the guide members G 1 , G 2  and G 5 , and sheet retaining board  121 . However, by the air blow shown by the arrow W 1 , conveyance of the sheet S 1  is conducted smoothly. 
     A direction of the air current shown by the arrow W 1  is a direction restricted by the guide members G 2  and G 5 . 
     As a result of sheet entering shown by  FIG. 4 , as  FIG. 5  shows, the sheet S 1  stops by contacting with the sheet stopper  123  and the sheet S 1  goes into a state shown by  FIG. 5  (stage  2 ). 
     Next, the sheet S 1  goes into a state shown by  FIG. 6  (stage  3 ). 
     In  FIG. 6 , the roller R 3  is displaced by rotation of a lever which rotates in an anticlockwise direction around a shaft of a lower roller of the roller pair R 2  by operating the solenoid SOL 1 , and a moving block configured with the guide members G 2  and G 5 , and the roller R 4  rotates around the axis X 1  in an anticlockwise direction by driving the solenoid SOL 2 . 
     As a result, as  FIG. 6  shows, a gap between the roller R 3  and the roller R 4  is formed and a gap between the roller R 4  and the roller R 5  is formed. Also, angles of the guide members G 2  and G 5  change. 
     Due to the change of the guide members G 2  and G 5 , the direction of the air current by the fax  126  changes as the air current W 2 . 
     The direction of the air current W 2  veers the air current away from the sheet storing section  12 , as a result the air current in the sheet conveyance path disappears. 
     In  FIG. 13 , changeover of the blower device from a high level to a low level and from the low level to the high level is described by on and off of the solenoid SOL 2  which displaces the guide member G 2  and G 5 . When the solenoid is turned on, the air blow stops (OFF) and when turning off the solenoid, the air blow starts (ON). 
     Since the direction of the air current is changed as the result of changing the guide members G 2  and G 5 , as  FIG. 13  shows, the timing of changing the guide members G 2  and G 3  and the timing of changing the direction of the air current coincide. 
     In the stage shown by  FIG. 6 , the sheet stopper  123  slightly ascends by the positive rotation of the motor M 4 , and the guide member G 3  rotates in the clockwise direction around the axis X 2 . By ascending the sheet stopper  123 , the upper end of the sheet S 1  ascends to a position higher than a lower end of the guide member G 5 . 
     By rotating the guide member G 3 , the sheet S 1  is moved to a left side board of the sheet retaining board  121 . Also, by aforesaid rotation of the guide members G 2  and G 5 , the direction of the air current changes as shown by W 2 , thus the sheet S 1  retained by the sheet stopper  123  cannot be blown by the air. 
     As  FIG. 6  shows, the upper end of the sheet S 1  ascends to the position higher than the lower end of the guide member G 5  without contacting with the guide member G 5 . 
     In a state of  FIG. 6 , the motor M 3  operated so that the width aligning device  122  aligns the sheet S 1  in the width direction. 
     Next the intermediary conveyance apparatus B goes into a state shown by  FIG. 7  (stage  4 ). 
     The state of the intermediary conveyance apparatus B in  FIG. 7  is the same as that of in  FIG. 4  except that the sheet stopper  123  is elevated. 
     In  FIG. 7 , the second sheets S 2  is nipped by the roller pair R 2  and rollers R 3  and R 4  to be conveyed. 
     In  FIG. 7 , the rollers R 3 , R 4  and R 5  contact each other and the air current shown by the arrow W 1  guides the second sheet S 2  and leads it into the sheet storing section  12 . As a result, the second sheet S 2  enters into the sheet storing section  12  smoothly. 
     As  FIG. 13  shows, immediately after the stage  4 , by rotating the motor M 4  in a reverse direction, the sheet stopper  123  descends and is set at a position where the sheet S 2  is received, thus the intermediary conveyance apparatus B goes into a stage  5  shown by  FIG. 8 . 
     The stage  5  shown by  FIG. 8  is the same as that in  FIG. 4 . In  FIG. 8 , two sheets S 1  and S 2  are retained by the sheet stopper  123 . 
     Immediately after the stage  5 , the motor M 4  operates to ascend the sheet stopper  123 . 
     As a result, the intermediary conveyance apparatus B goes into a state of  FIG. 9  (stage  6 ). In the  FIG. 9  the roller R 3  displaces and the moving block configured with the guide members G 2  and G 5  and the roller R 4  rotates in the anticlockwise direction around the axis X 1 . By the above rotation, a gap between the rollers R 3  and R 4 , and a gas between the rollers R 4  and R 5  are formed. Then as a result of ascent of the sheet stopper  123 , the upper ends of the two sheets S 1  and S 2  ascend to be higher than the rollers R 4  and R 5 . 
     In  FIG. 9 , the air current flows in a direction of the arrow W 2 , and veers away from the sheets S 1  and S 2 , thus ascending of the sheets S 1  and S 2  is not interrupted by the air current. 
     As  FIG. 9  shows, the gap is formed between the rollers R 4  and R 5  to release nipping of the sheet and the sheet stopper  123  ascends in a state where the upper ends of the sheets S 1  and S 2  are stopped by the longitudinal aligning board  128 . Whereby, the upper end of the sheets S 1  and S 2  are aligned and longitudinal aligning is performed. 
     In  FIG. 9 , the guide member G 3  rotates in the clockwise direction so as to move the sheets S 1  and S 2  to left side wall of the sheet retaining board  121 . 
     In  FIG. 9 , a third sheet S 3  enters via the roller pair R 1 . 
     In  FIG. 9 , the motor M 3  operates and the width aligning device  122  aligns the sheet S 2  in the width direction. 
     Next, the intermediary conveyance apparatus B goes into a state shown by  FIG. 10  (stage  7 ). The state shown by  FIG. 10  is the same as the state in  FIG. 4  except that the sheet stopper  123  is elevated. 
     In  FIG. 10 , the upper ends of the sheets S 1  and S 2  go above the rollers R 4  and R 5 , and the rollers R 4  and R 5  nip the sheets S 1  and S 2 . 
     Immediately after the stage  7 , solenoid SOL 4  operates so that the longitudinal aligning board  128  is retracted from the conveyance path and the guide member G 6  rotates in the clockwise direction. Whereby, an discharging conveyance path is formed. 
     In the state shown by  FIG. 11 , the roller R 5  and the roller pairs R 6  and R 7  rotate to discharge the sheets S 1  and S 2 . 
     By repeating the stages  2  to  8  shown by  FIGS. 5 to 11 , a continuous conveyance where the sheets are discharged from the intermediary conveyance apparatus B two by two. 
     Incidentally, it is possible that after storing one sheet or more than three sheets in a reversal conveyance section, the sheets are discharged. 
     &lt;Operation of Image Forming System&gt; 
     On the sheet discharging tray  23  of the post-processing apparatus FS, the sheets have to be discharged in a ascending order such as first sheet, second sheet . . . with the image surface side down in case of one-side image forming and with odd pages side down in case of two-side image forming. 
     The image forming apparatus A can discharge the sheet with the image surface side up (in case of one-side print) hereinafter called linier sheet discharging, and discharge the sheet with the image surface side down (in case of one-side print) hereinafter called reversal sheet discharging. 
     Also, the intermediary conveyance apparatus B has a linear conveyance function to discharge the sheet without reversing the sheet, and a reversal conveyance function where the sheet is conveyed from the sheet entering section  11  via the sheet storing section  12  to the sheet conveyance section  13  and discharged with reversing the sheet. 
     The image forming system shown in  FIG. 1  can discharge the sheet in order of page number from the post-processing apparatus with a high efficiency by combining the linear sheet discharging function and the reversal sheet discharging function of the image forming apparatus A and the linear sheet conveyance function and the reversal sheet conveyance function of the intermediary conveyance apparatus B. 
     For example, in a post-processing apparatus having a staple device and a shift device, the sheets brought in the post-processing apparatus FS are discharged to the sheet discharging tray  23  in order of entering without being reversed upside down. 
     In the above case, the image forming apparatus A performs the linear sheet discharging where the sheet is conveyed and discharged in a highest speed. In the intermediary conveyance apparatus B, the above reversal conveyance is conducted. As the result, the sheet is conveyed to the post-processing apparatus SF with the image surface side down (in case of one-side print), and the sheet is discharged and stacked in order of ascending with the image surface side down on the discharging sheet tray  23 . 
     Even in case a processable number of the sheets per minute of the post processing apparatus FS is smaller than that of the image forming apparatus A, by storing a plurality of the sheets in the sheet storing section  12  of the intermediary conveyance apparatus B, a difference between processing abilities of the image forming apparatus A and the post-processing apparatus FS is absorbed by the intermediary conveyance apparatus B. 
     There is another case that the image forming apparatus A performs two-side image forming by repeating obverse image forming and reverse image forming alternately. 
     In the above case, the image forming apparatus A conducts linear sheet discharging and the intermediary conveyance apparatus B conducts linear sheet conveyance. 
     By the above conveyance, the sheets are discharged and stacked in order of ascending in a manner that the odd page sides face downward. By providing the linear conveyance function in the intermediary conveyance apparatus B, complication of the conveyance path is obviated as above. 
     The post-processing apparatus FS has at least one of perforation processing, stapling processing, bookbinding processing and shift processing. In accordance with conditions such as the image forming mode (one-side or two-side), a size of the sheet, a kind of the sheet represented by a thick sheet, an environment (temperature and humidity) and processing mode of the post-processing apparatus FS, an optimum combination is selected among the linear sheet discharging or the reversal sheet discharging of the image forming apparatus A and the linear sheet conveyance or the reversal sheet conveyance of the intermediary conveyance apparatus B. 
     For example, whether or not multiple sheets are stored in the sheet storing section  12  and number of the sheets is determined by comparing a sheet processing speed of the image forming apparatus A and a sheet processing speed of the post-processing apparatus FS. 
     Incidentally, the conveyance guide of the sheet to the sheet storing section by the blower device is particularly needed in case the sheet storing section  12  stores multiple sheets, namely in case the sheet is conveyed in a state that the sheet exists in the sheet storing section  12 . 
     Whereby, it is preferable that in case the multiple sheets are not stored in the sheet storing section  12 , the blower device is not operated. 
     In the above case, air blow is ceased by stopping the fan  126 .