Abstract:
An envelope filling apparatus is an apparatus for inserting a sheet of paper into an envelope having a flap, including envelope feed means, an air nozzle for blowing air into an envelope fed by the envelope feed means from an open end of the envelope to open the open end, and sensing means for detecting that the open end of the envelope has been opened. The apparatus further includes insertion means for inserting a sheet of paper into an envelope from an open end, if the sensing means has detected that the open end of the envelope has been opened after the air nozzle is actuated, and removal means for removing an envelope from a transport route, if the sensing means does not detect that the open end of the envelope has been opened after the air nozzle is actuated and the insertion means is not actuated. The apparatus can detect whether a front and a back as well as forward and backward ends of an envelope into which a sheet of paper is to be inserted are placed properly for sheet insertion without requiring complicated and expensive means and cumbersome man-hours.

Description:
1. FIELD OF THE INVENTION 
       [0001]    The present invention relates to an envelope filling apparatus which is, for example, installed adjacent to an image forming apparatus or the like for inserting a printed sheet of paper discharge from the image forming apparatus or the like into an envelope fed to a prescribed position. Particularly, the invention relates to an envelope filling apparatus capable of properly determining whether the front and back as well as the forward and backward ends of an envelope in the feed position are placed in a state fit for sheet insertion without introduction of a complicated and expensive facility. 
       2. DESCRIPTION OF RELATED ART 
       [0002]    For example, business enterprises and other organizations may deliver to users and the like by mail print pieces and the like in envelopes containing necessary information according to various purposes such as notice and contact statement, advertising statement, billing statement, and others to users, organization members, etc. To do this, it is necessary to insert the print pieces and the like into envelopes. This workload becomes very large depending on the number of users to receive them and the number of types of documents to send out. Therefore, it is desirable to perform envelope filling work for folding and inserting a document into an envelope efficiently by using an automated machine. 
         [0003]    JP-A No. Hei 5-92841 discloses an envelope feed controller for types of envelopes which senses incorrect positioning of an envelope in regard to the front and back as well as the forward and backward ends of the envelope and prevents erroneous printing. Some means for sensing the front and back as well as the forward and backward ends of an envelope are disclosed, including mechanical sensing means based on a weight difference between one side of an envelope with flaps and the other side without flaps and the use of a device for sensing the thicknesses of the parts of an envelope with a transmission sensor, a distance sensor using laser, or the like. 
         [0004]    JP-A No. Hei 6-60244 discloses a mechanism for depositing money in an envelope for an automatic teller machine. This mechanism is intended to reduce faults in a transport path and to improve user operability and prevent erroneous operation. Following a shutter, an image sensor is installed to read letters and graphics on the surface of an envelope. The thus read letters and graphics are compared to standard envelope data and subjected to screening. The front and back of an envelope and its forward and backward ends are distinguished, the position of a print head is corrected by a position shifting mechanism, and control is performed for printing in a correct position on the envelope surface. 
         [0005]    According to the invention described in JP-A No. Hei 5-92841, the mechanical sensing means for detecting the front and back of an envelope based on a weight difference between one side of an envelope with flaps and the other side without flaps is incapable of sensing With accuracy due to individual difference of envelopes. All the sensing means including this mechanical sensing means in the invention described in JP-A No. Hei 5-92841 are complicated and expensive, thus resulting in rather a high price of the apparatus as a whole. Like the sensing means in the invention described in JP-A No. Hei 5-92841, in the way of sensing that directly senses the presence of flaps, the front and back of an envelope can be perceived, but the forward and backward ends of an envelope cannot be determined correctly. 
         [0006]    According to the invention described in the above-mentioned JP-A No. Hei 6-60244, since letters and graphics printed or transcribed on the surface of an envelope are necessary, printing on envelopes needs to be performed, consuming man-hours. Further, there is a possibility of printing on a wrong side. 
         [0007]    With the foregoing problems in view, an object of the present invention is to provide an envelope filling apparatus capable of correctly sensing and determining whether the front and back as well as the forward and backward ends of an envelope into which a sheet of paper is to be inserted are placed properly for sheet insertion without requiring complicated and expensive means and cumbersome man-hours. 
       SUMMARY OF THE INVENTION 
       [0008]    According to a first aspect of the invention, an envelope filling apparatus for inserting a sheet of paper into an envelope with its open end having a flap is provided, the apparatus including: 
         [0009]    envelope feed means for feeding an envelope oriented in a fixed orientation to a prescribed position; 
         [0010]    an air nozzle for blowing air into an envelope fed by the envelope feed means from the open end of the envelope to open the open end; and 
         [0011]    sensing means installed above an envelope fed by the envelope feed means for detecting that the open end of the envelope has been opened. 
         [0012]    A second aspect of the invention resides in the envelope filling apparatus according to the first aspect, wherein the air nozzle is configured to blow air toward a position corresponding to a flap of an envelope placed in the prescribed position by the envelope feed means. 
         [0013]    A third aspect of the invention resides in the envelope filling apparatus according to the first aspect, further including retaining means for retaining a flap of an envelope placed in the prescribed position by the envelope feed means. 
         [0014]    A fourth aspect of the invention resides in the envelope filling apparatus according to the second or third aspect, further including: 
         [0015]    insertion means for inserting a sheet of paper into an envelope from an open end, if the sensing means has detected that the open end of the envelope has been opened after the air nozzle is actuated; and 
         [0016]    removal means for removing an envelope from a transport route, if the sensing means does not detect that the open end of the envelope has been opened after the air nozzle is actuated and the insertion means is not actuated. 
         [0017]    A fifth aspect of the invention resides in the envelope filling apparatus according to the forth aspect, further including: 
         [0018]    two pairs of envelope rolling rollers disposed in two (fore and rear) positions just before and after spacing which is shorter than a length of an envelope in a stage following the position of the envelope fed by the envelope feed means, wherein the envelope rolling rollers convey an envelope containing a sheet of paper inserted therein to a prescribed position for discharge and guide an envelope containing no sheet of paper to a prescribed position for discharge; 
         [0019]    wherein the removal means includes a separator having a fulcrum point in the center of an envelope transport path between the two pairs of envelope rolling rollers and a mechanism adapted such that, after an envelope containing no sheet of paper is conveyed by the envelope rolling rollers until the longitudinal center of the envelope comes to the fulcrum point of the separator, the envelope rolling rollers in each of the two pairs are separated from each other to release the nipping of the envelope, and the envelope is let fall in an underneath position for removal by rotating around the fulcrum point by its own weight. 
         [0020]    A sixth aspect of the invention resides in the envelope filling apparatus according to the fifth aspect, wherein the removal means rotates the envelope rolling rollers in the rear position reversely to normal rotation for conveying an envelope downstream, when letting the envelope fall in the position for removal by rotating around the fulcrum point by its own weight. 
         [0021]    According to the envelope filling apparatus of the first aspect, when the envelope feed means feeds an envelope oriented in a fixed orientation to a prescribed position, the air nozzle blows air into the envelope from its open end and the air expands the envelope, thereby opening the open end. When the sensing means installed above an envelope detects that the open end of the envelope has been opened, the operation of inserting a sheet of paper into the envelope can be performed using the result of the detection, so that the sheet of paper can be inserted into the envelope properly. If the sensing means installed above an envelope does not detect that the open end of the envelope has been opened after the air nozzle is actuated, this means that the open end of the envelope is not placed with the flap down in the position toward which air is blown by the air nozzle and air from the air nozzle has not entered the envelope. It is thus detected and determined that the front and back as well as the forward and rearward ends of the envelope are not placed in a state not fit for sheet insertion. Accordingly, using such result of the detection by the sensing means, the operation of removing the envelope from the process or a similar operation can be performed without performing the operation of inserting a sheet of paper into the envelope. 
         [0022]    According to the envelope filling apparatus of the second aspect, in the effect achieved by the envelope filling apparatus of the first aspect, because air from the air nozzle is blown toward a position corresponding to the flap of the envelope place in the prescribed position by the envelope feed means, if the front and back as well as the forward and rearward ends of the envelope are placed properly for sheet insertion, the air hitting against the inner face of the flap presses the flap and fixates the position of the envelope and the air hitting against the flap enters the envelope and expands the envelope. If the front and back as well as the forward and rearward ends of the envelope are placed improperly for sheet insertion, the air from the air nozzle does not enter the envelope. 
         [0023]    According to the envelope filling apparatus of the third aspect, in the effect achieved by the envelope filling apparatus of the first aspect, because the retaining means retains the flap of the envelope placed in the prescribed position by the envelope feed means before the air nozzle performs air injection, the envelope can be expanded by injecting air so that the air will enter the open end instead of directing the air injected from the air nozzle directly toward the inner face of the flap and it is avoided that the envelope is displaced by the farce of the air. 
         [0024]    According to the envelope filling apparatus of the fourth aspect, in the effect achieved by the envelope filling apparatus of the second or third aspect, if the sensing means has detected that the open end of the envelope has been opened after the air nozzle is actuated, the insertion means is actuated to insert a sheet of paper into the envelope from the open end. If the sensing means does not detect that the open end of the envelope has been opened after the air nozzle is actuated and the insertion means is not actuated, the removal means is activated to remove the envelope from the transport route. 
         [0025]    According to the envelope filling apparatus of the fifth aspect, in the effect achieved by the envelope filling apparatus of the fourth aspect, if the front and back as well as the forward and rearward ends of an envelope are placed properly and a sheet of paper has been inserted into the envelope, the envelope rolling rollers convey the envelope to the prescribed position for discharge. If the front and back as well as the forward and rearward ends of an envelope are placed improperly and no sheet of paper has been inserted into the envelope, after the envelope rolling rollers convey the envelope containing no sheet of paper until the longitudinal center of the envelope comes to the fulcrum point of the separator, the envelope rolling rollers in each of the two pairs are separated from each other to release the nipping of the envelope. The envelope falls in the underneath position for removal by rotating around the fulcrum point by its own weight. At this time, the envelope drops with the open end and flap up and the closed bottom end down. Thus, disadvantage such as damaging the flap when the envelope drops is avoided and the envelope removed as an empty one can be returned to the envelope feed means and used again for sheet insertion. 
         [0026]    According to the envelope filling apparatus of the sixth aspect, in the effect achieved by the envelope filling apparatus of the fifth aspect, by rotating the envelope rolling rollers in the rear position reversely to normal rotation for conveying an envelope downstream, the rotation of the envelope around the fulcrum point by its own weight is intensified. This can further ensure that the envelope falls in the position for removal with the heavier bottom end down and the lighter open end and flap up. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  is an overall structural diagram of an envelope filling apparatus of a first embodiment; 
           [0028]      FIG. 2  is a structural diagram of sheet insertion means and its periphery in the envelope filling apparatus of the first embodiment, when viewed from the right side in  FIG. 1 ; 
           [0029]      FIG. 3A  is a cross sectional view of the sheet insertion means holding a rolled sheet, when viewed from a perspective parallel to an axis line, in the envelope filling apparatus of the first embodiment, and  FIG. 3B  is a perspective view of the sheet insertion means, when viewed from a perspective perpendicular to the axis line; 
           [0030]      FIG. 4  an enlarged view of envelope feed means and a retaining means in the envelope filling apparatus of the first embodiment; 
           [0031]      FIGS. 5A to 5C  are sequential operation diagrams in a case where envelope rolling rollers in the first embodiment operate as removal means; 
           [0032]      FIG. 6  is a diagram indicating a central position of an envelope which is removed in the first embodiment; and 
           [0033]      FIG. 7  is a timing diagram with regard to the operations of respective parts representing actions in the first embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0034]    An envelope filling apparatus  1  pertaining to an embodiment relates to an envelope filling apparatus which is installed adjacent to a paper collection tray or the like of an image forming apparatus or the like. If an envelope fed to a prescribed position is placed in a fixed orientation (in regard to its front and back and forward and rearward ends) fit for sheet insertion, the apparatus can insert a printed sheet of paper discharged from the image forming apparatus or the like into the envelope by insertion means and convey it to a prescribed position. If the orientation of the envelope is not proper, the apparatus can remove the envelope from the line without inserting a sheet of paper into the envelope. 
         [0035]    The image forming apparatus  100  shown in  FIG. 1  is comprised of an image forming unit, not shown, which forms an image such as letters and graphics on a sheet of paper with a prescribed size and a paper collection tray  5  in which sheets of paper having an image formed thereon discharged from the image forming unit are stacked. In  FIG. 1 , a sheet of paper having an image formed thereon is discharged from the image forming unit of the image forming apparatus  100  assumed to be present in front in the view of  FIG. 1  along a vertical direction in the view toward the paper collection tray  5  present in the back in the view. 
         [0036]    As is shown in  FIG. 1 , downstream of the paper collection tray  5  with respect to a direction of sheet discharge, that is, further in the back of the paper collection tray  5 , insertion means  6  is provided adjacent to the tray. The insertion means  6  rolls a sheet of paper P around an axis line which is parallel to the view and horizontal, moves the sheet of paper P parallel to the axis line in a transverse direction (indicated by arrow A) in the view, and inserts the sheet into an envelope E. 
         [0037]    As is shown in  FIG. 2  and  FIG. 3 , the insertion means  6  is comprised of a cylindrical cover  7  for keeping a sheet of paper P rolled and a roll-up roller  8  disposed coaxially with and inside the cover  7  for rolling up a sheet of paper P inside the cover  7 . 
         [0038]    As is shown in  FIG. 2  and  FIG. 3 , in the peripheral surface of the outer cover  7  of the insertion means  6 , a slit-like opening  9  is formed parallel to the axis line, which allows a sheet of paper P being fed to enter the insertion means. Of both end faces of the cover  7 , one end face facing the open end  18  of an envelope includes an open discharge outlet  10  from which a part of a sheet of paper P rolled and carried inside the cover  7  protrudes. The central axis of the cover  7  coincides With the axis line of the roll-up roller  8  which turns to roll up a sheet of paper P. 
         [0039]    As is shown in  FIG. 2 , the opening  9  of the cover  7  is in a position relative to the leading end of the sloped paper collection tray  5  of the image forming apparatus  100 . Above the opening  9  of the cover  7 , an end fence  11  being at an acute angle to the feed direction of a sheet of paper P is installed, fixed to the apparatus frame which is not shown. This end fence  11  serves to guide a sheet of paper P being fed across the paper collection tray  5  to the opening  9  of the cover  7 . 
         [0040]    As is shown in  FIG. 2  and  FIG. 3 , the peripheral surface of the inner roll-up roller  8  of the insertion means  6  is provided with a clamp plate  12  as means for holding back the leading edge of a sheet of paper P which is going to be fed from the opening  9  of the cover  7 . The clamp plate  12  is installed in a slit-like groove  13  formed in the roll-up roller  8 . This groove  13  is formed such that it is parallel to the axis line at the peripheral surface and oriented intersecting with the radial direction of the roll-up roller  8  in its depth direction. The clamp plate  12  can be projected from and retracted into the slit-like groove  13 , as appropriate, by drive means such as a solenoid which is not shown, and thus can hold back the leading edge of a sheet of paper P onto the peripheral surface of the roll-up roller  8  and release it, when appropriate. 
         [0041]    As is shown in  FIG. 2 , as turning means, a rotary motor M 1  is installed on the axis line of the roll-up roller  8 , so that the roll-up roller  8  is configured to be allowed to turn in a prescribed roll-up direction when the cover  7  and the roll-up roller  8  are set in a position to receive a sheet of paper P. Therefore, by setting the cover  7  and the roll-up roller  8  in a prescribed position to receive a sheet of paper P, retaining the leading edge of a sheet of paper P being fed by the clamp plate  12 , and turning the roll-up roller  8  around the axis line by the rotary motor M 1 , the sheet of paper P is pulled in the cover  7  and can be wrapped around the peripheral surface of the roll-up roller  8 . 
         [0042]    As is shown in  FIG. 1 , the cover  7  is equipped with motion means for causing a reciprocal motion of the cover  7  and the roll-up roller  8  along the axis line. The motion means is comprised of an insert motor M 2 , a crank plate  14  placed on the rotary shaft of the insert motor M 2  and rotating in a clockwise direction in the view of  FIG. 1 , and an interlocking member  15  which connects the crank plate  14  to the other end of the cover  7 . The cover  7  in which the roll-up roller  8  is installed is guided so that it can reciprocate in the axis line direction by guide means not shown. Thus, by driving the insert motor M 2  and rotating the crank plate  14 , the rotation of the crank plate  14  is transmitted to the cover  7  by the interlocking member  15 , and the cover  7  and the roll-up roller  8  can make a direct motion reciprocating in a horizontal direction in the view of  FIG. 1 . 
         [0043]    Also, as is shown in  FIG. 1 , the crank plate  14  is provided with an insert motor H-point switch (marked H in  FIG. 1 ) and an insert motor S-point switch (marked S in  FIG. 1 ) in two 180-degree opposite positions in the rotational direction, as means for sensing the position of the cover  7  driven by the insert motor M 2 . The insert motor H-point switch is turned ON when the guide cover  7  is in a home position farthest from an envelope. E, whereas the insert motor S-point switch is turned ON when the guide cover  7  is in a set position where it has been inserted deepest into an envelope. 
         [0044]    A relationship in dimensions among the cover  7  and the roll-up roller  8  in the insertion means  6  and a sheet of paper P is defined as is shown in  FIG. 3 . That is, if the dimension of a sheet of paper P in a direction perpendicular to the feed direction of a sheet of paper P is assumed to be the width (sheet width) L of a sheet of paper P, a roller width L R , which is the dimension of the roll-up roller  8  along the axis line direction, should be 0.6 L or more and a cover width L C , which is the dimension of the cover  7  along the axis line direction, should be 1.2 L R =0.72 L, where a relationship among the dimensions is L&gt;L C &gt;L R . As is shown in  FIGS. 3A and 3B , hence, the roll-up roller  8  is completely accommodated in the cover  7  without projecting outside the cover  7  and, when a rolled sheet of paper P is held between the cover  7  and the roll-up roller  8 , a part of the rolled sheet of paper P will protrude from the discharge outlet  10  of the cover  7 . 
         [0045]    As is shown in  FIG. 1 , with respect to the transport direction, envelope feed means  16  is provided downstream of and adjacent to the insertion means  6 . The envelope feed means  16  feeds an envelope by serially moving up a stack of multiple sheets of envelopes E with moving up/down means like an elevator. Each time an envelope E at the top of the stack is used, the moving up/down means moves up a bundle of envelopes E by a necessary distance so that an envelope at the top is always set in the insertion position. It is detected by envelope sensing means  17  that an envelope E at the top has been positioned in the insertion position. Envelopes E stacked in the envelope feed means  16  are oriented so that their open ends  18  are oriented upstream and face the discharge outlet  10  of the cover  7  of the insertion means  6  and their flaps  19  are present on the downside with the open ends  18  being visible from above. 
         [0046]    That is, it is assumed that envelopes E are stacked and set in the envelope feed means  16  in a fixed orientation (in regard to their front and back as well as forward and rearward ends), as stated above, which is considered as a normal state. 
         [0047]    As is shown in  FIG. 1 , above the top envelope E among the envelopes E stacked in the envelope feed means  16 , an air nozzle  20  is installed as month opening means to open the open end  18  of the envelope E. The air nozzle  20  is means for blowing air into an envelope E to open the open end  18  of the envelope E at the top. After the open end  18  of the envelope E is opened by air from the air nozzle  20 , by moving the insertion means  6  holding a rolled sheet of paper P inside it in the axis line direction (indicated by arrow A), the sheet of paper P protruding from the discharge outlet  10  of the cover  7  of the insertion means  6  and a part of the discharge outlet  10  side of the cover  7  of the insertion means  6  are inserted into the envelope E from the open end  18 . 
         [0048]    According to the embodiment shown in  FIG. 1 , the air nozzle  20  is configured to blow air toward the upper surface of the flap  19  extending upstream the open end  18  of the envelope E placed in the prescribed position. Thus, if the envelope feed means  16  positions an envelope E in the normal orientation as stated above and the envelope is properly oriented with the flap  19  on the downside extending upstream (toward the insertion means  6 ) in the longitudinal direction, air from the air nozzle  20  hits against the inner face of the flap  19  (the upper surface of the flap of the top envelope positioned properly) and fixates the envelope E, and then enters the envelope E from the open end  18 . Therefore, even if the envelope E is not retained by special means, the envelope E is not moved by the air. The envelope E expands as the air enters the envelope E and becomes ready for insertion of a sheet of paper P into it by the insertion means  6 . 
         [0049]    However, as is shown in  FIG. 4  as a modification example, retaining means  30  for envelopes E which can move up and down and move back and forth in the directions of arrows shown in  FIG. 4  may be installed adjacent to the upstream side of the envelope feed means  16 , thereby keeping the envelope E in the prescribed position of envelope feed means  16  and retaining it in place when the air nozzle  20  is actuated. In this case, the air nozzle  20  does not need to blow air toward the upper surface of the flap  19  extending upstream the open end  18  of the envelope E and can be configured to blow air from a more upstream point and the degree of freedom of arranging components of the apparatus increases. Because envelopes E are retained, there is no possibility of moving the envelope E even by fairly strong air injection of the air nozzle  20 . Thus, increased air injection power or injection time of the air nozzle  20  may be used to further ensure that the envelope E expands by the air. 
         [0050]    As is shown in  FIG. 1 , correct envelope position sensing means  21  is installed above and in the upstream side of the envelope feed means  16 . The correct envelope position sensing means  21  is adapted to sense the vicinity of the open end  18  of the top envelope E placed in the sheet insertion position in the envelope feed means  16 . When the air nozzle  20  is actuated and air enters the envelope E from the open end  18 , the envelope E expands by the air, as shown in  FIG. 1 , and the open end  18  side is raised and becomes closer to the correct envelope position sensing means  21 . The correct envelope position sensing means  21  detects a change in the distance to the open end  18  and can detect that the open end  18  of the envelope E has opened and become a state fit for sheet insertion by the insertion means  6 . 
         [0051]    As is shown in  FIG. 1 , a pickup roller  22  is installed above and in the downstream side of the envelope feed means  16 . The pickup roller  22  can move up and down, as appropriate, by drive means not shown, and is rotatable by drive means not shown. After a sheet of paper P is inserted into the top envelope E in the envelope feed means  16 , the pickup roller  22  comes in contact with the upper surface of the envelope E in the downstream side, while rotating, so that it can make the envelope E travel downstream. 
         [0052]    As is shown in  FIG. 1 , envelope rolling rollers  23  which nip the envelope E in which a rolled sheet of paper P has been inserted and convey the envelope downstream are installed downstream of the envelope feed means  16 . The envelope rolling rollers  23  nip and press the rolled sheet of paper P contained in the envelope E along with the envelope E, while rolling the envelope E. As a result, the rollers discharge the envelope containing the sheet of paper P folded to a size up to the inner dimensions of the envelope. The envelope rolling rollers  23  are two pairs of upper and lower rollers disposed along the transport direction. Upstream ones are referred to as first envelope rolling rollers  23   a  and downstream ones are referred to as second envelope rolling rollers  23   b . The length in the axial direction of each envelope rolling roller  23  is larger than the width of an envelope E. Spacing between the first envelope rolling rollers  23   a  and the second envelope rolling rollers  23   b  in the transport direction is shorter than the length of an envelope E. 
         [0053]    As is shown in  FIG. 1 , a filled envelope tray  24  is installed downstream of the envelope rolling rollers  23  and an envelope E (filled envelope E) into which a sheet of paper is inserted, after being rolled, is discharged to this tray. 
         [0054]    In the present embodiment, if the top envelope E in the envelope feed means  16  is normally oriented with the flap  19  being on the downside and the open end  18  facing toward the insertion means  6 , the air nozzle  20  opens the open end  18  and the insertion means  6  can insert a sheet of paper into the envelope. In that case, the above envelope rolling rollers  23  convey the envelope E and discharge it to the filled envelope tray  24 . Otherwise, after the air nozzle  20  is actuated, if the correct envelope position sensing means  21  does not detect that the open end  18  of the envelope E has opened and the insertion means  6  is not actuated, the orientation of the envelope E is regarded as incorrect. Consequently, removal means is configured to separate this empty envelope E from the transport route and remove it to a prescribed position. 
         [0055]    The removal means is comprised of a separator  40  having a fulcrum point  41  in the center of the envelope transport path between the above two pairs of envelope rolling rollers  23   a ,  23   b  which operate in a different way than normal conveyance operation as will be described later. Further, an envelope travel distance sensing means  31  which detects the travel distance of an envelope E is disposed between the above two pairs of envelope rolling rollers  23   a ,  23   b . A box-type container  50  for receiving, an envelope E removed and dropped from the envelope rolling rollers  23  is disposed under the above two pairs of envelope rolling rollers  23   a ,  23   b . The corners of the bottom of the container  50  are formed into curved surfaces  50   a  to alleviate a dropping impact on an envelope E dropped. In the vicinity of the top opening of the container  50 , discharged envelope sensing means  33   a  is installed under the first envelope rolling rollers  23   a  and discharged envelope sensing means  33   b  is installed under the second envelope rolling rollers  23   b.    
         [0056]    Then, among actions taking place in the above-described structure, a paper P rolling up operation and an insertion operation to insert rolled paper P into an envelope by the insertion means  6  are described with reference to  FIGS. 1 through 3B . 
         [0057]    As is shown in  FIG. 2 , a sheet of paper P having an image formed thereon is discharged from the image forming apparatus  100  onto the paper collection tray  5 , while it is guided by side fences  101 . Once a number of sheets to be inserted into one envelope E have been discharged, a sheets feed pawl  25  of the paper collection tray  5 , while moving from upstream to downstream in the paper discharge direction, pushes the rear edges of the sheets of paper P on the paper collection tray  5  to convey them to the insertion means  6 . The sheets of paper P are guided by the side fences  101  and fed into the cover  7  from the opening  9  of the cover  7  of the insertion means  6  set in the paper receiving position. Then, the sheets hit against the lower part of the clamp plate  12  of the roll-up roller  8 . Even if the sheets of paper P moved by the sheets feed pawl  25  protrude above the clamp plate  12 , because the end fence  11  is attached to the top end of the clamp plate  12 , the sheets of paper P hit against the end fence  11  and then are guided to the lower part of the clamp plate  12 . 
         [0058]    When the clamp plate  12  is actuated, it holds back the forward edges of the sheets of paper P between it and the peripheral surface of the roll-up roller  8 . The rotary motor M 1  is driven to turn the roll-up roller  8  and the sheets of paper P are pulled in the cover  7 . Once the roll-up roller  8  has rotated in one turn, as shown in  FIG. 3A , the holding back of the sheets of paper P by clamp plate  12  is released. Depending on the type, thickness, and the number of the sheets of paper P, the sheets of paper P spread in a circle by their resilience, contact the inner wall of the cover  7 , remaining rolled in a cylindrical form, then are held by the inner wall. As is shown in  FIG. 1  and  FIG. 3B , one end part of the sheets of paper P rolled in a cylindrical form protrudes out of the discharge outlet  10  of the cover  7 . 
         [0059]    As is shown in  FIG. 1 , in the insertion means  6  set in the paper receiving position, when the sheets of paper P are held in a cylindrical form as described above and become ready to be inserted, the air nozzle  20  is actuated to blow air to the open end  18  of an envelope E and the air expands the envelope E and opens the open end  18 . 
         [0060]    When the insert motor M 2  of the insertion means  6  is actuated, it moves the cover  7  and the roll-up roller  8  holding the sheets of paper P in a cylindrical form toward the envelope E and inserts the sheets of paper P along with the cover  7  and the roll-up roller  8  into the envelope E. When the insertion means  6  has inserted the sheets of paper P up to the farthest point in the envelope E, the pickup roller  22  and the envelope rolling rollers  23  start to operate and start to convey the envelope E downstream. 
         [0061]    The envelope rolling rollers  23  nip and convey the envelope E downstream, whereas the insert motor M 2  of the insertion means  6  moves the cover  7  and the roll-up roller  8  in a direction of withdrawal from the envelope E. Thereby, the sheets of paper P are removed from the cover  7  and the roll-up roller  8  within the envelope E, forwarded downstream along with the envelope E, pressed within the envelope E, and spread and folded to a size defined by the dimensions of the envelope E. 
         [0062]    Given that, in this way, sheets of paper Pare rolled up in a cylindrical form and inserted into an envelope E by the insertion means  6  and the envelope E is nipped and conveyed by the envelope rolling rollers  23 , the work of pressing and folding the sheets of paper P within the envelope E can be performed efficiently and surely in a simple process using the compact apparatus structure. 
         [0063]    Among actions taking place in the above-described structure, the separating action of the removal means which removes an envelope E into which no sheet of paper P has been inserted will be described next with reference to  FIG. 1 ,  FIGS. 5A to 5C , and  FIG. 6 . 
         [0064]    As previously described, if the position of an envelope E is incorrect, no sheet of paper P is inserted into the envelope E. Then, the envelope E containing no sheet of paper E is conveyed downstream by the pickup roller  22  shown in  FIG. 1  and further conveyed by the first envelope rolling rollers  23   a , while the envelope travel distance sensing means  31  shown in  FIG. 1  detects the travel distance of the envelope E. When the longitudinal center of the envelope E shown in  FIG. 6  (indicated by a center line C) has come to the fulcrum point  41  of the separator  40 , as is shown in  FIG. 5A , the envelope rolling rollers  23  stop their driving. 
         [0065]    As is shown in  FIG. 5B , of the first envelope rolling rollers  23   a  and the second envelope rolling rollers  23   b , the upper rollers and the lower rollers move upward and downward respectively and go apart from each other. This brings the envelope E in a state where the longitudinal center of the envelope E is supported only by the fulcrum point  41  of the separator  40 . 
         [0066]    As is shown in  FIG. 6 , for an unused envelope E, its top end (upstream in the transport direction in this example), i.e., the open end  18  is open with the flap  19  being not closed and its bottom end  26  (downstream in the transport direction in this example) is pasted and closed. When comparing the weights of both sides with respect to the longitudinal center line C, the side of the top end with the flap  19  is lighter and the side of the closed bottom end  26  is heavier. 
         [0067]    Consequently, as is shown in  FIG. 5C , when the upper and lower rollers of the first envelope tolling rollers  23   a  and the second envelope rolling rollers  23   b  separate, the envelope. E supported only by the fulcrum point  41  of the separator  40  becomes unbalanced such that the bottom end which is relatively heavy descends and the top end with the flap  19  which is relatively light ascends. 
         [0068]    Further, as is shown in  FIG. 5C , when the upper and lower rollers of the first envelope rolling rollers  23   a  and the second envelope rolling rollers  23   b  separate, at the same time, the first envelope rolling rollers  23   a  start to rotate forward (as in normal roller operation) and the second envelope rolling rollers  23   b  start to rotate reversely (reverse to normal rotation). Thereby, the inclination of the envelope E with the flap  19  end ascending and the bottom end descending is intensified by the rotations of the first envelope rolling rollers  23   a  and the second envelope rolling rollers  23   b . Eventually, the envelope E drops with the flap  19  up invariably. Dropping and keeping of the envelope E in the container  50  are detected by the discharged envelope sensing means  33   a ,  33   b.    
         [0069]    In this way, an envelope E dropped from the envelope rolling rollers  23  drops inside the container  50  with the flap  19  up invariably. This prevents the flap  19  from being broken or damaged due to its collision with the bottom of the container  50 . Envelopes E thus collected in the container  50  can be set again and used in the envelope feed means  16 , properly aligned in normal orientation. 
         [0070]    The apparatus of the present embodiment is provided with a controller  200  for controlling and driving the above-described components as shown in  FIG. 1  comprehensively. The function of the controller is to receive signals from the sensors and the like in the apparatus and operate the insertion means  6  and the removal means as described above, based on a program prestored in a storage means. Moreover, its function is to control the respective parts of the apparatus as will be described blow. 
         [0071]    In the following, descriptions will be provided for the actions to take place in the above described structure, mainly referring to a timing chart of  FIG. 7 , with the focus on the actions to take place in a case where no sheet of paper P is inserted into an envelope E and the envelope E is separated and removed. Symbols t 1  to t 5  referred to in the following description indicate timing in time sequence with regard to  FIG. 7  and numbers in parentheses indicate item numbers relevant to the actions and the like. 
         [0072]    Timing t 1 : The elevator of the envelope feed means  16  operates to set an envelope E in a prescribed insertion position. When the envelope sensing means  17  detects that an envelope E is placed in the normal insertion position and outputs a sensing signal ( 1 ), the air nozzle  20  is actuated to blow air into the envelope E and the air expands the envelope E ( 2 ). 
         [0073]    Timing t 2 : During the actuation of the air nozzle  20  for a predetermined given time T 1 , if the correct envelope position sensing means  21  does not output a sensing signal (when sensing is OFF), denoted as a dotted line in  FIG. 7 , the pickup roller  22  conveys an empty envelope E downstream ( 4 ) and the envelope rolling rollers  23  also start rotation and start to convey the envelope E downstream ( 6 ). 
         [0074]    Although not shown in  FIG. 7 , in a case where the correct envelope position sensing means  21  outputs a sensing signal (when sensing is ON), as supposedly implied by the dotted line in  FIG. 7 , during the actuation of the air nozzle  20  for the given time T 1 , this situation means that the envelope E is placed in the normal orientation and the open end  18  has been opened by air from the air nozzle  20  and, therefore, the insertion means  6  operates to insert the rolled sheets of paper P into the envelope E, as previously described. Then, the pickup roller  22  conveys the envelope E downstream and the envelope rolling rollers  23  further convey the envelope E, while pressing the envelope E. Thereby, the sheets of paper P are pressed and folded within the envelope E and then the envelope E is conveyed to the filled envelope tray  24 . 
         [0075]    Timing t 3 : Upon the elapse of a time T 2  corresponding to the time during which the envelope rolling rollers  23  convey the envelope E by L/2 which is a half the length L of the envelope E, the envelope travel distance sensing means  31  detects the center of the envelope E conveyed by the envelope rolling rollers  23  ( 7 ). The sensing signal issued by the envelope travel distance sensing means  31  causes the pickup roller  22  to stop ( 4 ) and to move upward ( 5 ) (see  FIG. 5B ) and causes the rotation of the envelope rolling rollers  23  to stop ( 6 ) (see  FIG. 5A ). At the same time, this signal causes the first envelope rolling rollers  23   a  and the second envelope rolling rollers  23   b  to move apart from each other ( 8 ) (see  FIG. 5B ) and causes the first envelope rolling rollers  23   a  located relatively nearer to the printer to rotate forward and the second envelope rolling rollers  23   b  located at the discharge side to rotate reversely ( 9 ) (see  FIG. 5C ). 
         [0076]    Timing t 4 : Upon the elapse of at least a given time T 3  during which the state continues where the upper and lower rollers of the first envelope rolling rollers  23   a  and the second envelope rolling rollers  23   b  separate ( 8 ) and the first envelope rolling rollers  23   a  rotate forward while the second envelope rolling rollers  23   b  rotate reversely ( 9 ), the envelope E mounted on the fulcrum point  41  of the separator  40  becomes unbalanced and drops in the container  50 . 
         [0077]    Timing t 5 : When the discharged envelope sensing means  33   a  or  33   b  disposed at the entrance of the container  50  detects the envelope E, its sensing signal triggers the stop of the rotations of the first envelope rolling rollers  23   a  and the second envelope rolling rollers  23   b  ( 9 ). Then, the separate upper and lower rollers of the first envelope rolling rollers  23   a  and the second envelope rolling rollers  23   b  are reverted to contact each other ( 8 ) and the pickup roller  22  is moved down to return to the position where it can convey an envelope downstream ( 5 ). 
         [0078]    As described hereinbefore, according to the embodiment of the present invention, in the envelope filling apparatus  1  provided with the functions of opening the open end  18  of an envelope E placed in a prescribed orientation by air and inserting a sheet of paper P into the envelope E, if the orientation of an envelope E is incorrect, this envelope is separated from envelopes E containing sheets of paper P normally inserted therein. Such envelopes without contents can be removed from the normal insertion and transport route and carried to and collected in another place. To separate such empty envelopes E, a method is used in which the envelope falls by its own weight from the normal route with the flap  19  up which is liable to be damaged by impact. Therefore, this prevents the flap  19  of the separated envelope E from being damaged and the envelope E is stored in the container  50  with the flap  19  up. These envelopes can be served for reuse, when they are set with their front and back being aligned properly in the envelope feed means  16 .