Patent Publication Number: US-2012026263-A1

Title: Image forming apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 USC 119 from Japanese Patent Application No. 2010-170693 filed Jul. 29, 2010, the disclosure of which is incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image forming apparatus. 
     2. Related Art 
     Japanese Patent Application Laid-Open No. 2000-118840 discloses a blanking plate on which image-formed sheets of paper discharged from an image forming apparatus or the like are stacked. In a case in which a predetermined number of sheets of paper are stacked on the blanking plate, another blocking plate is stacked on the stacked sheets of paper so as not to press the stacked sheets, thereby suppressing an image formed on a sheet of paper from being transferred to another sheet of paper. 
     In the related art, since image-formed sheets of paper are sequentially stacked, it is considered that the sheets of paper come in close contact with each other and thus the sheets of paper are not adapted to the surrounding environment. 
     SUMMARY OF THE INVENTION 
     The present invention is to effectively adapt stacked sheets of paper to the surrounding environment (perform seasoning) and to stabilize the posture of the stacked sheets of paper. 
     According to a first aspect of the invention, there is provided an image forming apparatus including: an image forming apparatus main body that ejects ink droplets onto a sheet of paper to form an image; and a seasoning device that is disposed in a discharge unit to which the sheet of paper having an image formed thereon by the image forming apparatus main body is discharged, wherein the seasoning device includes a separation section that separates stacked sheets of paper on which images are formed into a sheet bundle, an air blowing member that blows air toward an end portion of the sheet bundle separated by the separation section, and a moving member that moves a position at which the air is blown to the end portion of the sheet bundle by the air blowing member in an up and down direction in which the sheets of paper are stacked. 
     According to this configuration, the separation member separates (makes) the stacked sheets of paper image being formed into the sheet bundle. The air blowing member blows air to an end portion of the sheet bundle separated (made) by the separation member so as to blow the air between the stacked sheets of paper. The moving member moves the position at which the air is blown to the end portion of the sheet bundle by the air blowing member in an up and down direction in which the sheets of paper are stacked. 
     In this way, by moving the position at which the air is blown in the up and down direction, it is possible to effectively adapt the stacked sheets of paper to the surrounding environment and to stabilize the posture of the stacked sheets, compared with the case in which air is simultaneously blown to all of the stacked sheets of paper. 
     A second aspect of the invention provides the image forming apparatus according to the first aspect, in the aspect, the apparatus further includes a first controller that controls an air volume of the air blowing member, and the first controller sets the air volume of the air blowing member when the air is blown toward the end portion at a lower side of the sheet bundle to be larger than the air volume of the air blowing member when the air is blown toward the end portion at an upper side of the sheet bundle. 
     According to this configuration, the first controller sets the air volume (quantity) of the air blowing member when the air is blown to the lower side end portion of the sheet bundle to be larger than the air volume of the air blowing member when the air is blown to the upper side end portion of the sheet bundle. Accordingly, it is possible to efficiently blow air to the sheets of paper on the lower side to which the weight of the sheets of paper of the upper side is loaded and thus to effectively adapt the sheet bundle to the surrounding environment. 
     A third aspect of the invention provides the image forming apparatus according to the first aspect, in the aspect, the apparatus further includes a second controller that controls an air pressure of the air blowing member, and the second controller sets the air pressure of the air blowing member when the air is blown toward the end portion at a lower side of the sheet bundle to be higher than the air pressure of the air blowing member when the air is blown toward the end portion at an upper side of the sheet bundle. 
     According to this configuration, the second controller sets the air pressure of the air blowing member when the air is blown to the lower side end portion of the sheet bundle to be larger than the air pressure of the air blowing member when the air is blown to the upper side end portion of the sheet bundle. Accordingly, it is possible to efficiently blow air to the sheets of paper on the lower side to which the weight of the sheets of paper of the upper side is loaded and thus to effectively adapt the sheet bundle to the surrounding environment. 
     A fourth aspect of the invention provides the image forming apparatus according to the third aspect, in the aspect, an air nozzle of the air blowing member is a variable air nozzle, of which an opening area is variable, and the second controller changes the air pressure of the air nozzle by changing the opening area of the variable air nozzle. 
     According to this configuration, the second controller changes the air pressure of the air nozzle by changing the opening area of the variable air nozzle of the air blowing member. In this way, it is possible to change the air pressure of the air blowing member with a simple structure. 
     A fifth aspect of the invention provides the image forming apparatus according to the third or fourth aspect, in the aspect, the second controller controls the moving member such that a moving speed at which the position at which the air is blown is moved in the up and down direction is set so that the moving speed, at a time when the position is moving on the end portion at the lower side of the sheet bundle, is slower than the moving speed, at a time when the position is moving on the end portion at the upper side of the sheet bundle. 
     According to this configuration, the second controller controls the moving member such that a moving speed at which the position at which the air is blown is moved in the up and down direction is set so that the moving speed, at a time when the position is moving on the end portion at the lower side of the sheet bundle, is slower than the moving speed, at a time when the position is moving on the end portion at the upper side of the sheet bundle. Accordingly, it is possible to efficiently blow air to the sheets of paper on the lower side to which the weight of the sheets of paper of the upper side is loaded and thus to effectively adapt the sheet bundle to the surrounding environment. 
     A sixth aspect of the invention provides the image forming apparatus according to any one of the first to fifth aspects, in the aspect, the apparatus further includes a temperature and humidity adjusting unit that adjusts temperature and humidity, and the air blowing member blows normal-temperature and normal-humidity air adjusted by the temperature and humidity adjusting unit to the end portion of the sheet bundle. 
     According to this configuration, the air blowing member blows normal-temperature and normal-humidity air adjusted by the temperature and humidity adjusting unit to the end portion of the sheet bundle. Accordingly, it is possible to suppress the deformation of the sheets, for example, compared with the case in which warm air is blown. 
     A seventh aspect of the invention provides the image forming apparatus according to any one of the first to sixth aspects, in the aspect, the air pressure of the air blowing member is set to a static pressure which is equal to or greater than 500 Pa. 
     According to this configuration, the air pressure of the air blowing member is set to a static pressure which is equal to or greater than 500 Pa. Accordingly, it is possible to satisfactorily blow air between the sheets of paper overcoming the pressure loss between the sheets of paper (it is possible to improve the air blowing efficiency). 
     An eighth aspect of the invention provides the image forming apparatus according to any one of the first to seventh aspects, in the aspect, the separation section is curved in a convex shape toward the upper side as viewed from an air blowing direction of the air blowing member. 
     According to this configuration, the separation member is curved in a convex shape toward upper side as viewed in the air blowing direction of the air blowing member. Accordingly, if the curl of the sheets of paper is strong, it is possible to regulate the sheet plane of the sheet end portion in the air blowing direction to be parallel to the air blowing direction, thereby stabilizing the ventilation between sheets of paper. 
     A ninth aspect of the invention provides the image forming apparatus according to any one of the first to seventh aspects, in the aspect the separation section is curved in a convex shape toward the lower side as viewed from an air blowing direction of the air blowing member. 
     According to this configuration, the separation member is curved in a convex shape toward lower side (in a concave shape) as viewed in the air blowing direction of the air blowing member. Accordingly, when the curl of the sheets of paper is strong, it is possible to regulate the sheet plane of the sheet end portion in the air blowing direction to be parallel to the air blowing direction, thereby stabilizing the ventilation between sheets of paper. 
     According to the above-mentioned configurations of the invention, it is possible to effectively adapt the stacked sheets of paper to the surrounding environment and to stabilize the posture of the stacked sheets. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will be described in detail with reference to the following drawings, wherein: 
         FIG. 1  is a side view illustrating a seasoning device according to a first embodiment of the invention; 
         FIG. 2  is a front view illustrating the seasoning device according to the first embodiment of the invention; 
         FIG. 3  is a plan view illustrating the seasoning device according to the first embodiment of the invention; 
         FIG. 4  is a side view illustrating the seasoning device according to the first embodiment of the invention; 
         FIG. 5  is a perspective view illustrating a housing and the like used in the seasoning device according to the first embodiment of the invention; 
         FIG. 6  is a diagram schematically illustrating an image forming apparatus used for the seasoning device according to the first embodiment of the invention; and 
         FIGS. 7A and 7B  are perspective views illustrating an air blower and the like used in a seasoning device according to a second embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A seasoning device  58  and an image forming apparatus  10  according to a first embodiment of the invention will be described below with reference to  FIGS. 1 to 6 . Arrow UP in the drawings represents an upside in a vertical direction. 
     Entire Configuration 
     As shown in  FIG. 6 , an image forming apparatus  10  includes a paper feed unit  12  that feeds a sheet of paper P as a recording medium to an apparatus body  10 A, a process liquid applying unit  14  that applies a process liquid to an image forming surface of the sheet of paper P, an image forming unit  16  that forms an image on the sheet of paper P, a drying unit  18  that reduces the moisture of (dries) the sheet of paper P so as to enhance strength of image layer of an image-formed portion in which an image is formed, a fixing unit  20  that fixes the formed image to the sheet of paper P, and a discharge unit  22  to which the sheet of paper P is discharged. 
     The sheets of paper P are stacked on the paper feed unit  12  and the sheets of paper P are sent out to the apparatus body  10 A by the paper feed unit  12  sheet by sheet. A feed tray  24  guiding the sheet of paper P sent out from the paper feed unit  12  to the apparatus body  10 A is disposed downstream side in the transporting direction of the sheet of paper P (hereinafter, simply referred to as “downstream side”) with respect to the paper feed unit  12 . A feed drum  26  rotating and transporting the sheet of paper P along the outer circumferential surface thereof is disposed in the apparatus body  10 A downstream side with respect to the feed tray  24 . The sheet of paper P is transported to the process liquid applying unit  14  by the feed drum  26 . 
     The process liquid applying unit  14  includes a process liquid applying drum  28 , with rotating, receiving the sheet of paper P transported by the feed drum  26  and transporting the sheet of paper P along the outer circumferential surface thereof. Specifically, a holding member  30  holding the end of the sheet of paper P is disposed on the outer circumferential surface of the process liquid applying drum  28 . According to this configuration, the sheet of paper P is transported downstream side by means of the rotation of the process liquid applying drum  28  in the state in which the end of the sheet of paper P is held by the holding member  30 . 
     A process liquid applying device  32  applying the process liquid to the image forming surface of the sheet of paper P transported by the process liquid applying drum  28  is disposed above the process liquid applying drum  28 . The process liquid has an effect of reacting with liquid droplets to be described later to aggregate a coloring material (pigment) and to promote the separation of the coloring material (pigment) from the solvent. 
     A transporting drum  34 , with rotating, receiving the sheet of paper P transported by the process liquid applying drum  28  and transporting the sheet of paper P to the image forming unit  16  is disposed downstream side with respect to the process liquid applying drum  28 . 
     The image forming unit  16  includes an image forming drum  36 , with rotating, receiving the sheet of paper P transported by the transporting drum  34  and transporting the sheet of paper P along the outer circumferential surface thereof. A liquid droplet ejecting head  38  ejecting liquid droplets of ink or the like to the sheet of paper P transported by the image forming drum  36  to form an image on the sheet of paper P is disposed above the image forming drum  36 . The liquid droplet ejecting head  38  is a so-called full-line head having an ink ejecting range corresponding to the maximum width of the sheet of paper P. In this embodiment, the liquid droplet ejecting heads  38  of four colors of Y (Yellow), M (Magenta), C (Cyan), and K (Black) as exemplary basic colors are arranged in the circumferential direction of the image forming drum  36 . 
     A transporting drum  40  receiving the sheet of paper P transported by the image forming drum  36  and transporting the sheet of paper P to the drying unit  18  is disposed downstream side with respect to the image forming drum  36 . 
     The drying unit  18  includes a drying drum  42 , with rotating, receiving the sheet of paper P transported by the transporting drum  40  and transporting the sheet of paper P along the outer circumferential surface thereof. A halogen heater  44  and a warm air nozzle  46  as an example of a drying member are disposed above the drying drum  42 . While the sheet of paper P is being transported by the drying drum  42 , the moisture contained in the sheet of paper P is reduced (dried) by means of the heat from the halogen heater  44  and the warm air from the warm air nozzle  46  so as to enhance the strength of image layer of the image-formed portion in which an image is formed. Accordingly, the strength of image layer of the image formed on the sheet of paper P is improved. 
     A transporting drum  48  receiving the sheet of paper P transported by the drying drum  42  and transporting the sheet of paper P to the fixing unit  20  is disposed downstream side with respect to the drying drum  42 . 
     The fixing unit  20  includes a fixing drum  50 , with rotating, receiving the sheet of paper P transported by the transporting drum  48  and transporting the sheet of paper P along the outer circumferential surface thereof. A halogen heater  61  for heating (preliminary heating), a fixing roller  63  pressing the sheet of paper P against the fixing drum  50 , and an in-line sensor  65  measuring a check pattern, an amount of moisture, a surface temperature, a gloss level, and the like of the sheet of paper P are disposed to face the outer circumferential surface of the fixing drum  50 . 
     A discharge drum  52 , with rotating, receiving the sheet of paper P transported by the fixing drum  50  and discharging the received sheet of paper P to the outside of the apparatus body  10 A is disposed downstream side with respect to the fixing drum  50 . 
     A guide plate  54  formed in a curved shape so as to guide the sheet of paper P to the outside of the apparatus body  10 A is disposed downstream side with respect to the discharge drum  52 . 
     The sheet of paper P discharged to the outside of the apparatus body  10 A is discharged to a seasoning device  58  disposed in the discharge unit  22  by the discharge drum  52 . The details of the seasoning device  58  will be described later. 
     Main Configuration 
     As shown in  FIG. 1 , the seasoning device  58  includes a housing  60  having a box shape of which the bottom is opened and a blanking device  62  disposed adjacent to the housing  60 . 
     A separation plate section  66  as an example of the separation member separating the sheets of paper P into a sheet bundle  64  is disposed in the housing  60 . The separation plate section  66  is configured to include an upper separation plate  66 A disposed above the sheet bundle  64  and a lower separation plate  66 B on which the sheet bundle  64  is placed. 
     That is, a predetermined number of (for example, 300 to 500) sheets of paper P are stacked and supported on the lower separation plate  66 B to form the sheet bundle  64  and the upper separation plate  66 A is disposed above the sheet bundle  64 . That is, the sheet bundle  64  is housed in a sheet bundle housing space  70  formed between the lower separation plate  66 B and the upper separation plate  66 A. Hereinafter, the sheet bundle  64 , the lower separation plate  66 B which is at the lower of the sheet bundle  64 , and the upper separation plate  66 A which is at the upper of the sheet bundle  64  together is called a sheet bundle unit  72 . 
     As shown in  FIG. 2 , the upper separation plate  66 A and the lower separation plate  66 B has a shape in which the center portion in a width direction (the direction of arrow B shown in  FIG. 2 , which is simply referred to as a width direction) as viewed in an air blowing direction of an air blower  104  as an example of the air blowing member to be described later is raised and both end portions in the width direction are lowered, that is, an upwardly-convex shape (arch shape). 
     As shown in  FIGS. 2 and 3 , four corners of the upper separation plate  66 A protrude in the width direction (protruding portions), and spacers  74  protruding toward the lower separation plate  66 B from the bottom surfaces of the protruding portions are provided. The spacers  74  have a predetermined height H 2  so that even when the lower end portion of the spacer  74  comes in contact with the top surface of the lower separation plate  66 B, a predetermined gap for housing the sheet bundle  64  is guaranteed (ensured) between the lower separation plate  66 B and the upper separation plate  66 A, as described later. 
     As shown in  FIG. 5 , the housing  60  has a box shape of which the bottom is opened. A front side plate  60 A of the housing  60 , which is disposed on the side from which the separation plate section  66  and the sheets of paper P are input to the inside of the housing  60 , is lower in the up and down direction than the other side plates, so as to form an input concave portion  76  in the housing  60 . 
     As shown in  FIG. 1 , a pallet support  78  on which the separation plate section  66  (the sheet bundle unit  72 ) housing the sheet bundle  64  therein is placed is disposed below the housing  60 . Specifically, a pallet  82  having casters  80  is supported on the pallet support  78  and the sheet bundle unit  72  having been subjected to the seasoning (performing of the seasoning is finished) to be described later is placed on the top surface of the pallet  82 . 
     On the other hand, the blanking device  62  inputting the separation plate sections  66  to the inside of the housing  60  includes a separation plate support  84  on which the separation plate sections  66  including the upper separation plate  66 A and the lower separation plate  66 B are placed. The lower separation plates  66 B and the upper separation plates  66 A are alternately placed on the separation plate support  84 . The separation plate support  84  goes up and down so that the uppermost separation plate section  66  (two plates, that is, the lower separation plate  66 B and the upper separation plate  66 A) is located at a height corresponding to the input concave portion  76  of the housing  60 . 
     The blanking device  62  includes input rods  86 A and  86 B pressing the end portions of the uppermost separation plate section  66  (end portions of the lower separation plate  66 B and the upper separation plate  66 A) in the direction of arrow C and inputting the separation plate section  66  to the inside of the housing  60  through the input concave portion  76 . The blanking device  62  includes a guide member not shown in the drawings so as to prevent the careless inclination or dropping of the separation plate section  66  and to smoothly input the separation plate section  66  to the inside of the housing  60 . 
     As shown in  FIG. 5 , a pair of separation plate lowering devices  88  supporting and lowering the input separation plate section  66  are disposed on the inner surface of the housing  60 . 
     Each separation plate lowering device  88  includes an endless lowering belt  90  and a driving pulley  92  and a driven pulley  94  that are disposed in lined up manner in the up and down direction and on which the lowering belt  90  is wound. Support pieces supporting the separation plate section  66  are arranged vertically at a constant interval on the outer circumferential surface of the lower belt  90 . Specifically, the support pieces  96  support the side portions of the separation plate section  66  (the side portions of the lower separation plate  66 B and the side portions of the upper separation plate  66 A) input to the inside of the housing  60 . 
     Here, the relative position in the up and down direction of the support pieces  96  are set so that the spacer  74  do not contact with the lower separation plate  66 B in a state in which the lower separation plate  66 B and the upper separation plate  66 A are supported by the support pieces  96 . 
     The driving pulley  92  is connected to a driving shaft (not shown in the drawings) and is rotationally driven in the direction of arrow R 1  (see  FIG. 2 ) by the use of a driving motor (not shown in the drawings). By means of this rotational driving, the lowering belt  90  is circulated and moved and the lower separation plate  66 B and the upper separation plate  66 A are lowered at a constant lowering speed while maintaining a predetermined gap therebetween. 
     At this time, the lowering-amount (lowering speed) is set depending on the increasing speed in height of the sheets of paper P by the sequential housing of the sheets of paper P in the housing  60 . 
     On the other hand, as shown in  FIGS. 1 ,  3  and  5 , six openings  100  extending in the up and down direction are formed in the front side plate  60 A, disposed on the side from which the sheets of paper P are input, of the housing  60 , and six openings  102  extending in the up and down direction to face the openings  100  are formed in a rear side plate  60 B facing the front side plate  60 A. Six blowers  104  blowing air to the end portion of the sheet bundle  64  housed in the housing  60  through the openings  100  are disposed. 
     Moving members  106  as an example of the moving member (see  FIG. 4 ) moving the six blowers  104  along the openings  100  extending in the up and down direction are disposed. 
     A first controller  108  (see  FIG. 3 ) controlling the air blowers  104  and the moving members  106  are provided. The first control unit  108  controls the driving of the air blowers  104  so that the air volume (quantity) by which air is blown to the lower end portion of the sheet bundle  64  by the air blowers  104  is larger than the air volume by which air is blown to the upper end portion of the sheet bundle  64 . 
     As shown in  FIGS. 2 and 3 , in the state in which the separation plate section  66  is input to the inside of the housing  60  and the sheets of paper P are placed on the lower separation plate  66 B, both end sides facing in the width direction of the sheets of paper P go along the outer circumferential surfaces of the lowering belts  90  and both end sides facing in the depth direction of the sheets of paper P go along the front side plate  60 A and the rear side plate  60 B. That is, the lowering belts  90 , the front side plate  60 A, and the rear side plate  60 B have an air-leakage preventing guiding function. Accordingly, the air blown from the air blowers  104  is blown between the sheets of paper P of the sheet bundle  64  through the openings  100  formed in the front side plate  60 A and is discharged to the outside through the openings  102  formed in the rear side plate  60 B. 
     A temperature and humidity adjusting unit  110  (see  FIG. 4 ) adjusting the temperature and the humidity of the wind (air) blown to the sheets of paper P by the air blowers  104  is provided so that normal-temperature and normal-humidity air (having a constant temperature in the range of 5° C. to 35° C. and a constant humidity in the range of 45% RH to 85% RH) is blown to the end portion of the sheet bundle  64 . 
     Operation and Effect 
     As shown in  FIG. 6 , the sheet of paper P fed from the paper feed unit  12  is transported along the outer circumferential surfaces of the rotating feed drum  26  and the rotating process liquid applying drum  28 . In the process liquid applying unit  14 , the process liquid applying device  32  applies a process liquid to the image forming surface of the sheet of paper P transported along the outer circumferential surface of the process liquid applying drum  28 . 
     The sheet of paper P to which the process liquid has been applied is sent to the transporting drum  34  and is transported along the outer circumferential surfaces of the rotating transporting drum  34  and the rotating image forming drum  36 . In the image forming unit  16 , the liquid droplet ejecting heads  38  of the respective colors eject the liquid droplets of ink or the like to the image forming surface of the sheet of paper P transported by the image forming drum  36  to form an image on the sheet of paper P. 
     The sheet of paper P having an image formed on the image forming surface thereof is sent to the transporting drum  40  and is transported along the outer circumferential surfaces of the rotating transporting drum  40  and the rotating drying drum  42 . In the drying unit  18 , the sheet of paper P transported by the drying drum  42  is dried by means of the heat from the halogen heater  44  and the warm air blown from the warm air nozzle  46 . That is, the moisture contained in the sheet of paper P is reduced (dried), thereby enhancing the strength of image layer of the image-formed portion in which the image has been formed. 
     The sheet of paper P which is made to be to a high temperature by means of the heat from the halogen heater  44  and the warm air blown from the warm air nozzle  46  is sent to the transporting drum  48  and is transported along the outer circumferential surfaces of the rotating transporting drum  48  and the rotating fixing drum  50 . In the fixing unit  20 , the halogen heater  61  disposed to face the fixing drum  50  fixes the image formed on the sheet of paper P onto the sheet of paper P by means of heat. The sheet of paper P transported by the fixing drum  50  is pressed against the fixing drum  50  by the fixing roller  63  and passes through the portion facing the in-line sensor  65 . The in-line sensor  65  measures a check pattern, an amount of moisture, a surface temperature, a gloss level, and the like of the sheet of paper P passing therethrough. 
     The sheet of paper P having been subjected to the measurement by the in-line sensor  65  is sent to the discharge drum  52 , is transported along the outer circumferential surface of the rotating discharge drum  52 , is guided by the guide plate  54 , and is discharged to the discharge unit  22  outside the apparatus body  10 A. 
     In this embodiment, the printing speed is 2700 rph and thus images are formed on 2700 sheets per hour. 
     As shown in  FIG. 1 , the sheet of paper P discharged to the discharge unit  22  passes through the upper portion of the blanking device  62 , passes through the input concave portion  76 , and is stacked on the top surface of the lower separation plate  66 B disposed in the housing  60 . 
     As shown in  FIG. 2 , the lowering belt  90  is circulated by means of the driving power of the driving pulley  92 , and the lower separation plate  66 B that is supported by the support pieces  96  and on which the sheets of paper P having an image formed thereon are sequentially stacked is lowered. 
     At a time in which a predetermined number of (for example, 300 to 500) sheets of paper P are stacked as the sheet bundle  64  on the lower separation plate  66 B, as shown in  FIG. 1 , the input rods  86 A and  86 B input the upper separation plate  66 A and the lower separation plate  66 B placed on the separation plate support  84  to the inside of the housing  60 . 
     Accordingly, the input upper separation plate  66 A is disposed above the lower separation plate  66 B on which the sheet bundle  64  is placed. The first controller  108  drives the six blowers  104 . The air flow formed by the driving of the air blowers  104  is blown between the sheets of paper P of the sheet bundle  64  disposed between the lower separation plate  66 B and the upper separation plate  66 A through the openings  100  formed in the front side plate  60 A. The air blown between the sheets of paper P is discharged to the outside through the openings  102  formed in the rear side plate  60 B. In this way, the air is made to pass between the sheets of paper P, thereby adapting the sheets of paper P to the surrounding environment (performing seasoning). Here, in the embodiment, “performing seasoning” is, concretely, to adjust moisture content of the sheets of paper P (between the sheets of paper P), and the seasoning device  58  is a device to performing seasoning. 
     As shown in  FIG. 4 , the controller  108  controls the moving member  106  to move the position at which the air is blown to the end portion of the sheet bundle  64  in the up and down direction in which the sheets of paper are stacked. The controller  108  controls the driving of the air blowers  104  so that the air volume when the air is blown to the lower side end portion of the sheet bundle  64  by the air blowers  104  is larger than the air volume when the air is blown to the upper side end portion of the sheet bundle  64  by the air blowers  104 . The sheet bundle  64  is lowered while being subject to seasoning by means of the circulating movement of the lowering belts  90 . The controller  108  lowers the up and down movement range of the air blowers  104  according to (corresponding to) the lowering movement of the sheet bundle. The up and down moving period (cycle) is preferably in the range of 1 second to 60 seconds. 
     When the lowering belt  90  is further circulated, the lower separation plate  66 B on which the sheet bundle  64  is placed is released from the supporting of the support pieces  96  and the lower separation plate  66 B is placed on the top surface of the pallet  82 . The upper separation plate  66 A released from the supporting of the support pieces  96  is disposed so as to cover the sheet bundle  64  from the upside of the placed lower separation plate  66 B. 
     Here, by bringing the spacers  74  provided at the upper separation plate  66 A into contact with the top surface of the lower separation plate  66 B, the weight of the upper separation plate  66 A is prevented from being loaded onto the sheet bundle  64 . Then, the sheet bundle unit  72  having been subjected to the seasoning (performing of the seasoning has been finished) is transported by the pallet  82  and is moved to a storage space. By repeating the above-mentioned processes, the plural sheet bundle units  72  having been subjected to the seasoning are transported by the pallet  82  and are moved to a storage space. 
     As described above, by moving the position at which air is blown by the air blowers  104  in the up and down direction, it is possible to effectively adapt the stacked sheet bundle  64  to the surrounding environment (perform seasoning), compared with the case in which air is simultaneously blown to the entire sheet bundle (in which the position at which air is blown is not moved in the up and down direction). 
     By moving the position at which air is blown by the air blowers  104  in the up and down direction, it is possible to increase the number of sheets of paper which can be simultaneously processed (subject to seasoning), compared with the case in which air is simultaneously blown to the entire sheet bundle. 
     By moving the position at which air is blown by the air blowers  104  in the up and down direction, it is possible to stabilizer the posture (attitude) of the stacked sheets of paper P, compared with the case in which air is simultaneously blown to the entire sheet bundle. 
     The first controller  108  sets the air volume of the air blower  104  when the air is blown to the lower side end portion of the sheet bundle  64  to be larger than the air volume of the air blower  104  when the air is blown to the upper side end portion of the sheet bundle  64 . Accordingly, it is possible to efficiently blow the air to the lower side sheets of paper P on which the weight of the upper side sheets of paper P is loaded, thereby effectively adapting the sheet bundle  64  to the surrounding environment. 
     The first controller  108  sets the air volume of the air blower  104  when the air is blown to the lower side end portion of the sheet bundle  64  to be larger than the air volume of the air blower  104  when the air is blown to the upper side end portion of the sheet bundle  64 . Accordingly, it is possible to reduce the air volume blown to the upper side sheets of paper P on which the weight of the sheets of paper P is not loaded, thereby stabilizing the posture of the sheets of paper P. 
     Since the air blowers  104  blow the normal-temperature and normal-humidity air adjusted by the temperature and humidity adjusting unit  110  to the end portion of the sheet bundle  64 , it is possible to suppress the deformation of the sheets of paper P, compared with the case in which warm air or compressed air is blown. That is, since the image-non-formed portion (white background) is further dried with the warm air, so it is difficult to alleviate the deformation of the sheets. Since the air blowing efficiency between the sheets of paper P may be improved with the compressed air (of 10 kPa or more) but the air in a compressor is dehumidified to become dry air, the image-non-formed portion (white background) is further dried, whereby it is difficult to alleviate the deformation of the sheets of paper P. 
     The lower separation plate  66 B is curved in a convex shape toward upper side as viewed from the air blowing direction from the air blowers  104 . Accordingly, even when the curl of the sheets of paper P is strong, it is possible to regulate the sheet plane at the sheet end portion in the air blowing direction to be parallel to the air blowing direction, thereby stabilizing ventilation between the sheets of paper P. 
     In the state in which the sheets of paper P are stacked on the lower separation plate  66 B, both end portions, facing in the width direction, of the sheets of paper P go along the outer circumferential surfaces of the lowering belts  90 , and both end portions, facing in the depth direction, of the sheets of paper P go along the front side plate  60 A and the rear side plate  60 B. Accordingly, it is possible to suppress the air blown from the air blowers  104  from leaking to an unintended portion, thereby effectively adapting the sheet bundle  64  to the surrounding environment. 
     A seasoning device and an image forming apparatus  10  according to a second embodiment of the invention will be described below with reference to  FIGS. 7A and 7B . Arrow UP in the drawings represents the upside in the vertical direction. The same elements as the first embodiment are referenced by the same reference numerals and signs and description thereof is omitted. 
     As shown in  FIGS. 7A and 7B , an air blower  120  is a sirocco fan (for example, a sirocco fan SAN ACE B97 (9BMB24P2K01) made by SANYO DENKI CO., LTD.) and the air pressure of the blower  120  is set to a static pressure which is equal to or greater than 500 Pa. The air nozzle (air blowing opening) of the air blower  120  employs a variable air nozzle  122  of which the opening area is variable by changing the opening height. 
     A second controller  126  is provided which controls the air blower  120  and a moving member  124 . The second controller  126  sets the air pressure of the air blower  120  when the air is blown to the lower side end portion of the sheet bundle  64  to be higher than the air pressure of the air blower  120  when the air is blown to the upper side end portion of the sheet bundle  64 . Specifically, the opening height of the variable air nozzle  122  is changed to change the air pressure. 
     The second controller  126  controls the moving member  124  to set the moving speed of which the position at which the air is blown is moved in the up and down direction so that the moving speed of the position at the lower side is lower than the moving speed of the position at the upper side. 
     As described above, by setting the air pressure of the air blower  120  when the air is blown to the lower side end portion of the sheet bundle  64  to be larger than the air pressure of the air blower  120  when the air is blown to the upper side end portion of the sheet bundle  64 , it is possible to efficiently blow air to the lower side sheets of paper P on which the weight of the upper side sheets of paper P is loaded, thereby effectively adapting the sheet bundle  64  to the surrounding environment. 
     By setting the moving speed of which the position at which the air is blown is moved in the up and down direction so that the moving speed in the downside is lower than the moving speed in the upside, it is possible to efficiently blow air to the lower side sheets of paper on which the weight of the upper side sheets of paper P is loaded, thereby further effectively adapting the sheet bundle to the surrounding environment. 
     By setting the air pressure of the air blower  120  to a static pressure equal to or greater than 500 Pa, it is possible to satisfactorily acquire a high air blowing efficiency with overcoming the pressure loss between the sheets of paper P. 
     While the specific embodiments of the invention have been described in detail, the invention is not limited to the embodiments, but it will be apparent to those skilled in the art that the invention can be modified in various forms within the scope of the invention. For example, in the above-mentioned embodiments, the sheet plane of the sheet end portion in the air blowing direction is regulated to be parallel to the air blowing direction even when the curl of the sheets of paper P is strong, by curving the lower separation plate  66 B in a convex shape toward upper side as viewed in the air blowing direction. However, by curving the lower separation plate in a concave shape (convex shape toward lower side) as viewed in the air blowing direction (that is, in a state such that the lower separation plate  66 B in  FIG. 2  is curved in a convex shape toward lower side), it is possible to regulate the sheet plane of the sheet end portion in the air blowing direction to be parallel to the air blowing direction even when the curl of the sheets of paper is strong, thereby stabilizing the ventilation between sheets of paper P. 
     Although it has been described in the above-mentioned embodiments that the air blowers  104  and  120  are moved vertically to move the position at which the air is blown to the end portion of the sheet bundle  64  in the up and down direction, the position at which the air is blown may be moved in the up and down direction by vertically swinging the air nozzle of the air blower. 
     The above-mentioned embodiments can be properly combined without departing from the concept of the present invention.