Abstract:
An image-forming device includes: a main device body; a plurality of process cartridges; a fixing unit; a tray; a switchback conveying path; and a reverse conveying unit. The plurality of process cartridges are detachably mounted in the main device body. The process cartridges are arranged in a row in the main device body when the process cartridges are mounted in the main device body. Each process cartridge has an image-carrying member that transfers a developer image carried thereon to a sheet by opposing the sheet. The fixing unit is provided in the main device body and fixes the developer image to the sheet after the image has been transferred thereto. The tray is provided in the main device body and supports the sheet after the developer image has been fixed thereon. The switchback conveying path is provided in the main device body and guides the sheet from the fixing unit to the tray, while switching a conveying direction of the sheet. The reverse conveying unit is disposed in the main device body along the switchback conveying path and reverses the conveying direction of the sheet.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority from Japanese Patent Application No. 2005-77567 filed Mar. 17, 2005. The entire content of this priority application is incorporated herein by reference.  
       TECHNICAL FIELD  
       [0002]     The disclosure relates to an image-forming device, and particularly to a tandem type image-forming device.  
       BACKGROUND  
       [0003]     A vertical tandem type laser printer is disclosed in Japanese unexamined patent application publication No. 2003-186348. The vertical tandem type laser printer is one type of electrophotographic image-forming device.  
       SUMMARY  
       [0004]      FIGS. 1 and 2  show the structure of a conceivable laser printer of the vertical tandem type.  
         [0005]     As shown in  FIGS. 1 and 2 , the conceivable laser printer  100  includes four process cartridges  103  to correspond to the four colors used in image formation. Each process cartridge  103  has a photosensitive drum  101  and a toner-accommodating section  102 . The process cartridges  103  are accommodated in a main device body  104  of the laser printer  100  so as to be stacked vertically.  
         [0006]     The laser printer  100  further includes a paper cassette  105  disposed in a lower section of the main device body  104  for accommodating a paper  106 , and a conveying belt  107  disposed in a front section of the main device body  104  for conveying the paper  106  supplied from the paper cassette  105  in an upward direction. The process cartridges  103  are disposed so that the photosensitive drums  101  oppose the conveying belt  107 . The conveying belt  107  is retained in a cover  108  disposed on the front surface of the main device body  104  that is capable of opening and closing on the front surface. By opening the cover  108  together with the conveying belt  107  as shown in  FIG. 2 , the process cartridges  103  are exposed, enabling the user to replace the process cartridges  103 , resolve paper jams, and the like. An exposure device  109  for irradiating light on the photosensitive drums  101  is disposed on the rear side of the process cartridges  103 . The laser printer  100  further includes a fixing unit  110  and a discharge tray  111  disposed in a top section of the main device body  104 .  
         [0007]     With this construction, after the paper  106  conveyed upward along the conveying belt  107  passes through the fixing unit  110 , the paper  106  curves toward the rear side of the main device body  104  to be discharged onto the discharge tray  111 .  
         [0008]     However, since the laser printer  100  described above discharges the paper  106  toward the rear of the main device body  104 , it is difficult to retrieve the paper  106  after image formation. Retrieving the paper  106  becomes increasingly difficult when an original-reading unit is mounted on top of the discharge tray  111 . While it is conceivable to provide the discharge tray  111  on the front side of the fixing unit  110  so that the paper  106  curves toward the front to be discharged after passing through the fixing unit  110 , this configuration discharges the paper  106  onto the discharge tray  111  with the image formation surface face up. As a result, the order of pages is reversed when printing a plurality of sheets consecutively. Furthermore, the discharge tray  111  extends forward from the front of the device in this case, increasing the depth dimension of the overall image-forming device.  
         [0009]     As described above, the conceivable laser printer of the vertical tandem type suffers from various problems due to restrictions in the layout of the device related to paper conveyance.  
         [0010]     In view of the foregoing, it is an object of the invention to provide an image-forming device capable of resolving the various problems described above by increasing the amount of freedom in layout design related to paper conveyance.  
         [0011]     In order to attain the above and other objects, the invention provides an image-forming device including: a main device body; a plurality of process cartridges; a fixing unit; a tray; a switchback conveying path; and a reverse conveying unit. The plurality of process cartridges are detachably mounted in the main device body. The process cartridges are arranged in a row in the main device body when the process cartridges are mounted in the main device body. Each process cartridge has an image-carrying member that transfers a developer image carried thereon to a sheet by opposing the sheet. The fixing unit is provided in the main device body and fixes the developer image to the sheet after the image has been transferred thereto. The tray is provided in the main device body and supports the sheet after the developer image has been fixed thereon. The switchback conveying path is provided in the main device body and guides the sheet from the fixing unit to the tray, while switching a conveying direction of the sheet. The reverse conveying unit is disposed in the main device body along the switchback conveying path and reverses the conveying direction of the sheet. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     In the drawings:  
         [0013]      FIG. 1  is a cross-sectional view of a conceivable laser printer when a cover is closed thereon;  
         [0014]      FIG. 2  is a cross-sectional view of the conceivable laser printer in  FIG. 1  when the cover is open;  
         [0015]      FIG. 3  is a cross-sectional view of a laser printer according to one illustrative aspect of the invention when a cover is closed thereon;  
         [0016]      FIG. 4  is a cross-sectional view of the laser printer in  FIG. 3  when the cover is open;  
         [0017]     FIGS.  5 ( a ) through  5 ( g ) are cross-sectional views illustrating successive steps in a continuous printing process of the laser printer; and  
         [0018]      FIG. 6  is an explanatory diagram illustrating a simplified version of a paper-conveying path. 
     
    
     DETAILED DESCRIPTION  
       [0019]     A vertical tandem type color laser printer according to an illustrative aspect of the invention will be described with reference to  FIGS. 3 and 4 .  
         [0020]      FIGS. 3 and 4  show a general structure of a laser printer  1  according to this aspect.  FIG. 3  shows the laser printer  1  when a cover  14  is in a closed state, while  FIG. 4  shows the laser printer  1  when the cover  14  is in an open state. The terms “upward”, “downward”, “upper”, “lower”, “above”, “below”, “beneath”, “front”, “rear”, “right”, and “left” and the like will be used throughout the description assuming that the laser printer  1  is disposed in an orientation in which it is intended to be used. In use, the laser printer  1  is disposed as shown in  FIG. 3 .  
         [0021]     As shown in the drawings, the laser printer  1  includes a main casing  2 ; a paper cassette  4  disposed in a bottom section of the main casing  2  for accommodating sheets of a paper or other recording medium  3  in a stacked state, the paper cassette  4  capable of being pulled out of the main casing  2  in a forward direction; a feeding roller  5  disposed above a front end of the paper cassette  4  for conveying the paper  3  upward; and a feeding path  7  formed above the feeding roller  5  along which the paper  3  is conveyed from the feeding roller  5 . Although not shown in detail in the drawings, a paper sensor is disposed along the feeding path  7  for detecting the leading edge and trailing edge of the paper  3 . Based on these detection results, it is possible to determine the length and the like of the paper  3 .  
         [0022]     An access opening  8  is formed in the front surface of the main casing  2 . A cartridge-accommodating section  9  is formed inside the main casing  2  to the rear of the access opening  8 . Four process cartridges  10  corresponding to the colors black, cyan, magenta, and yellow are mounted in the cartridge-accommodating section  9  of the main casing  2  in a vertically stacked arrangement. More specifically, the process cartridges  10  are stacked in a slanted direction so as to be positioned progressively rearward from bottom to top.  
         [0023]     Each of the process cartridges  10  includes a toner-accommodating section  11  having a box shape for accommodating a toner, a photosensitive drum  12  on which an electrostatic latent image is formed, and a developing device (not shown) for developing the electrostatic latent image formed on the photosensitive drum  12  into a visible image with toner. Each process cartridge  10  is mounted in the cartridge-accommodating section  9  so that the photosensitive drum  12  faces the access opening  8  side and the toner-accommodating section  11  faces the rear side.  
         [0024]     The cover  14  is disposed on the front surface of the main casing  2  and is capable of opening and closing over the access opening  8 . In general, the cover  14  has a thick plate-shape with a shaft part  14 A provided on the lower end thereof. The shaft part  14 A is attached to the main casing  2  near the lower edge of the access opening  8  so that the cover  14  can rotate about the shaft part  14 A. The cover  14  can be moved between a closed position shown in  FIG. 3  in which the cover  14  covers the access opening  8 , and an open position shown in  FIG. 4  in which the cover  14  is rotated down from the front side of the main casing  2  so that the access opening  8  is exposed.  
         [0025]     An endless conveying belt  15  is extended along the inner surface of the cover  14  and has a vertical orientation when the cover  14  is in the closed position. The conveying belt  15  conveys the paper  3  fed from the feeding roller  5  along the feeding path  7  upward so that one surface of the paper  3  (the surface facing rearward) sequentially opposes each of the photosensitive drums  12 . Transfer rollers  13  (shown in  FIG. 6 , but omitted from the other drawings) are provided on the inside of the conveying belt  15  for opposing each of the photosensitive drums  12  and applying a transfer bias therebetween. As a result, of the transfer bias applied by the transfer rollers  13 , toner images formed on the photosensitive drums  12  are sequentially transferred onto the paper  3 .  
         [0026]     When the cover  14  is opened, the conveying belt  15  is displaced forward together with the cover  14 , exposing the front side of the photosensitive drums  12 . At this time, it is possible to mount or remove the process cartridges  10  via the access opening  8 . Further, opening the cover  14  facilitates operations for resolving paper jams and the like.  
         [0027]     An exposure device  16  is provided in the main casing  2  on the rear side of the cartridge-accommodating section  9 . The exposure device  16  includes a case  17  within which are provided laser light-emitting units (not shown), a polygon mirror  19  that is driven to rotate, various lenses  20  and reflecting mirrors  21 , and the like. As illustrated by the broken line in  FIG. 3 , the laser light-emitting units of the exposure device  16  emit laser beams based on image data for each color, and the laser beams are irradiated onto the surfaces of the respective photosensitive drums  12 , forming electrostatic latent images thereon.  
         [0028]     A fixing unit  23  is disposed in the main casing  2  above the conveying belt  15  when the cover  14  is in the closed position. The fixing unit  23  includes a heating roller  24  and a pressure roller  25  for fixing a toner image transferred onto the paper  3  to the surface of the paper  3  with heat while conveying the paper  3  downstream. A pair of reverse-conveying rollers  26  capable of rotating in both forward and reverse directions is disposed in the main casing  2  rearward of the fixing unit  23 , A discharge tray  27  is also provided in the main casing  2  above the fixing unit  23  for receiving the paper  3  after image formation. The discharge tray  27  extends toward the front of the main casing  2  and slopes slightly upward toward the front edge. A pair of discharge rollers  28  is disposed near the rear edge of the discharge tray  27  for conveying the paper  3  onto the discharge tray  27 .  
         [0029]     A switchback conveying path  30  (indicated by a dotted line in  FIGS. 3 and 4 ) is formed in the laser printer  1  for guiding the paper  3  conveyed from the fixing unit  23  to the discharge tray  27  after reversing directions. As will be described below, the switchback conveying path  30  includes an advancing path  30 A, a paper-retracting section  30 B, and a discharging path  30 C.  
         [0030]     The advancing path  30 A leads from a nip position between the heating roller  24  and pressure roller  25  in the fixing unit  23  to a nip point N between the reverse-conveying rollers  26  and substantially describes an arc shape with the curve of the arc on the top side. The paper-retracting section  30 B extends vertically downward from the nip point N of the reverse-conveying rollers  26 . The paper-retracting section  30 B is a slit-shaped space provided in the main casing  2  on the rear side of the exposure device  16  in which the paper  3  can be temporarily received when switching directions. The discharging path  30 C extends upward from the nip point N of the reverse-conveying rollers  26 , sharing the same path with the advancing path  30 A up to a branch point B. At the branch point B, the advancing path  30 A branches off of the discharging path  30 C in a direction sloping upward and forward, while the discharging path  30 C continues upward from the branch point B, curves forward toward the discharge rollers  28  at the top of the main casing  2 , and continues onto the discharge tray  27 .  
         [0031]     An original-reading unit  31  is disposed above the discharge tray  27  so as to cover a part of the same. The original-reading unit  31  is a flatbed scanner configured of a main body  31 A, and an automatic document feeder (ADF)  32  disposed above the main body  31 A. The user lifts the ADF  32  upward to expose a document-supporting surface formed on top of the main body  31 A. The original-reading unit  31  can read images from various documents placed on top of the document-supporting surface. A control panel  33  is also disposed on a top surface of the main body  31 A that protrudes forward from the ADF  32 . The control panel  33  enables the user to specify various operations to perform with the laser printer  1 . The main body  31 A of the original-reading unit  31  is fixed to the main casing  2  and cannot be withdrawn from a position above the discharge tray  27 .  
         [0032]     Next, operations of the laser printer  1  during continuous printing will be described. FIGS.  5 ( a ) through  5 ( g ) illustrate multiple stages in a continuous printing operation performed by the laser printer  1 . In the following description, it will be necessary to differentiate one sheet of the paper  3  from a sheet conveyed after this sheet. Hence, these sheets will be referred to as a first sheet  3 A and a second sheet  3 B, respectively.  
         [0033]     When the laser printer  1  begins the continuous printing operation, the feeding roller  5  feeds the first sheet  3 A from the paper cassette  4  to the conveying belt  15  via the feeding path  7 . As the conveying belt  15  conveys the first sheet  3 A upward, toner in each color is sequentially transferred from each photosensitive drum  12  onto the first sheet  3 A. Subsequently, the first sheet  3 A is conveyed through the fixing unit  23 , at which time the toner image on the first sheet  3 A is fixed to the first sheet  3 A by heat. In this example, the paper  3  is conveyed at a constant velocity by the conveying belt  15  and fixing unit  23 . This constant velocity will be denoted as V 1  (mm/sec). In the meantime, while the first sheet  3 A is being conveyed by the conveying belt  15 , the feeding roller  5  feeds the second sheet  3 B at a prescribed timing. The prescribed timing is set such that a gap G (mm) is formed between the trailing edge of the first sheet  3 A and the leading edge of the second sheet  3 B.  
         [0034]     As the first sheet  3 A passes through the fixing unit  23 , the advancing path  30 A of the switchback conveying path  30  guides the leading edge of the first sheet  3 A rearward (see  FIG. 5 ( a )). Before the leading edge of the first sheet  3 A reaches the nip point N between the reverse-conveying rollers  26 , the reverse-conveying rollers  26  are driven to rotate in a forward rotation for conveying the paper  3  downward. The rotational speed of the reverse-conveying rollers  26  on the peripheral surfaces thereof is set to the velocity V 1 . Therefore, when the leading edge of the first sheet  3 A arrives at the nip point N, the first sheet  3 A maintains the velocity V 1  while being conveyed into the paper-retracting section  30 B (see  FIG. 5 ( b )).  
         [0035]     After the trailing edge of the first sheet  3 A subsequently passes the branch point B where the advancing path  30 A branches from the discharging path  30 C (see FIG.  5 ( c )) and before the trailing edge of the first sheet  3 A reaches the nip point N of the reverse-conveying rollers  26 , the reverse-conveying rollers  26  begin rotating in reverse. Consequently, the conveying direction of the first sheet  3 A is reversed from a downward direction to an upward direction in what is referred to as a switchback operation so that the trailing edge side of the first sheet  3 A is conveyed onto the discharging path  30 C (see  FIG. 5 ( d )). At this time, the rotational speed of the reverse-conveying rollers  26  on the peripheral surface thereof, that is, the conveying velocity of the first sheet  3 A in the reverse direction, is set to a conveying velocity V 2  (mm/sec). Hence, the first sheet  3 A is guided upward and subsequently curved in a forward direction toward the discharge rollers  28  along the discharging path  30 C (see  FIG. 5 ( e )). The discharge rollers  28  then discharge the first sheet  3 A onto the discharge tray  27  at the same velocity V 2  (see  FIG. 5 ( f )). At this time, the first sheet  3 A is discharged with the image formation surface facing downward. By setting the conveying velocity V 2  of the first sheet  3 A for the reverse direction to a value greater than the velocity V 1  of the first sheet  3 A prior to reversal, it is possible to reduce the amount of time required to discharge the paper  3 A after the printing operation is begun.  
         [0036]     In the meantime, after the first sheet  3 A passes the branch point B, the second sheet  3 B arrives at the nip point N between the reverse-conveying rollers  26  and begins the same switchback conveyance operation described for the first sheet  3 A (see FIGS.  5 ( f ) and  5 ( g )). In other words, the second sheet  3 B is guided into the paper-retracting section  30 B by the reverse-conveying rollers  26  at the velocity V 1  and is subsequently discharged along the discharging path  30 C onto the discharge tray  27  at the velocity V 2 .  
         [0037]     Next, an example of settings for conveying velocities V 1  and V 2  of the sheets  3 A and  3 B prior to the switchback and after the switchback, respectively, and for the gap G formed between the first sheet  3 A and the second sheet  3 B will be described with reference to  FIG. 6 .  FIG. 6  is an explanatory diagram in which the conveying path for the paper  3  has been simplified.  
         [0038]     As shown in  FIG. 6 , the gap between the trailing edge of the first sheet  3 A and the leading edge of the second sheet  3 B along the sheet conveying path when the trailing edge of the first sheet  3 A arrives at the branch point B is the gap G (mm). Here, P (mm) will denote the length of the sheets  3 A and  3 B along the sheet conveying direction. From this position, the time required for the leading edge of the first sheet  3 A (the edge farthest into the paper-retracting section  30 B) to pass the branch point B when conveyed in reverse by the reverse-conveying rollers  26  is P/V 2 . If this time P/V 2  is smaller than a time G/V 1  required for the leading edge of the second sheet  3 B to reach the branch point B, then the first sheet  3 A and second sheet  3 B will not interfere with each other. Hence, the following equation can be derived. 
 
 P/V 2≦ G/V 1  (A) 
 
 This can be rewritten as: 
 
 V 1· P/V 2≦ G   (B) 
 
 Hence, it is possible to avoid conflict between the first sheet  3 A and second sheet  3 B by setting values for the conveying velocities V 1  and V 2  and the gap G between the first sheet  3 A and second sheet  3 B to satisfy Equation (B) above. When V 1  equals V 2 , G must be set to satisfy the following equation. 
 
P≦G  (C) 
 
         [0039]     In the vertical tandem type laser printer  1  described above, the paper  3  is guided along the switchback conveying path after an image has been fixed thereon before being discharged onto the discharge tray  27 . This configuration increases the layout freedom with respect to the conveyance of the paper  3 , thereby achieving a more convenient image-forming device by resolving the various problems in the conceivable configuration described above.  
         [0040]     Since the paper  3  is discharged onto the discharge tray  27  with the image formation surface face down, the page order is maintained when printing a plurality of pages in succession.  
         [0041]     Further, since the sheets of paper  3  are discharged in a direction toward the front side of the laser printer  1 , on which side the cover  14  is provided, establishing this side as the front of the laser printer  1  facilitates operations for retrieving the paper  3  from the discharge tray  27  and for mounting and removing the process cartridges  10 . In addition, the paper cassette  4  is removed from the main casing  2  through the same front side of the laser printer  1 , thereby facilitating operations for loading the paper  3  in the paper cassette  4 .  
         [0042]     Further, the switchback conveying path  30  is configured to switch conveying directions of the paper  3  on the rear side of the fixing unit  23  (toward the side of the laser printer  1  opposite the side on which the cover  14  is provided). This configuration enables the discharge tray  27  to be provided deeper in the main casing  2  (farther rearward) than when the paper  3  is conveyed along a forward curving path from the fixing unit  23  and is discharged onto a tray. Accordingly, it is possible to reduce the amount that the discharge tray  27  protrudes on the front side of the laser printer  1  (the cover  14  side).  
         [0043]     The paper-retracting section  30 B functioning to receive the paper  3  during the switchback operation is disposed inside the main casing  2 . This construction prevents the paper  3  from coming into contact with and potentially being soiled by objects outside the device during the switchback operation.  
         [0044]     Since the paper  3  is discharged toward the same surface side on which the cover  14  is provided (forward), the paper  3  can be retrieved more easily from the discharge tray  27 , even when the original-reading unit  31  is disposed above the discharge tray  27  so as to cover the same, than when the paper  3  is discharged in a direction away from the cover  14  (rearward).  
         [0045]     Discharging the paper  3  in a forward direction toward the surface on which the cover  14  is disposed is particularly convenient in laser printers  1  having an original-reading unit that cannot be withdrawn for retrieving the paper  3  from the discharge tray  27 .  
         [0046]     The conveying velocity V 2  may be set greater than the conveying velocity V 1 . That is, the conveying velocity of the paper  3  after the paper  3  has passed through the fixing unit  23  may be set greater than the conveying velocity prior to passing through the fixing unit  23 . More specifically, the conveying velocity of the paper  3  after the entire part of the paper  3  has passed through the fixing unit  23  may be set greater than the conveying velocity before the entire part of the paper  3  has passed through the fixing unit  23 . Accordingly, the time required for the paper  3  to be discharged onto the discharge tray  27  after the fixing operation can be reduced.  
         [0047]     Further, by switching the conveying velocity of the reverse-conveying rollers  26  at the same time the conveying direction is switched, the configuration of the conveying mechanism can be simplified compared to a configuration for switching the conveying direction and conveying velocity at separate times. Here, the conveying mechanism includes a drive motor for producing a driving force, and a gear mechanism or the like for transmitting the driving force to the conveying rollers, for example.  
         [0048]     Further, by satisfying Equation B described above, the first sheet  3 A and second sheet  3 B will not interfere with each other in the switchback operation during continuous printing. By minimizing the gap G between the first sheet  3 A and second sheet  3 B within the allowable range for satisfying the Equation (B), it is possible to shorten the time required for completing the entire printing operation.  
         [0049]     While the invention has been described in detail with reference to the above aspect thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention.  
         [0050]     For example, the following variations are possible.  
         [0051]     (1) While the process cartridges are arranged vertically in the above description, the process cartridges may instead be arranged along a slant, for example, such that the lowest process cartridge is closest to the front side, while the upper process cartridges are shifted sequentially toward the rear side.  
         [0052]     (2) While a paper-retracting section for receiving sheets during the switchback operation is provided inside the main device body of the image-forming device in the above description, the switchback operation may be performed while exposing the sheets outside the main device body.  
         [0053]     (3) While the conveying velocity of the sheets is increased in the above description upon switching the conveying direction of the sheets (during the switchback operation), the conveying direction and conveying velocity of the sheet may be switched separately.  
         [0054]     For example, the conveying velocity may be increased directly after the sheet has passed through the fixing unit. In other words, the conveying velocity may be increased directly after the entire part of the sheet has passed through the fixing unit.  
         [0055]     More specifically, in this modification, similarly to the above description, the paper  3  is conveyed at the constant velocity V 1  by the fixing unit  23 . As the sheet  3  passes through the fixing unit  23 , the advancing path  30 A of the switchback conveying path  30  guides the leading edge of the sheet  3  rearward. It is noted that the distance along the advancing path  30 A between the fixing unit  23  and the nip point N between the reverse-conveying rollers  26  is smaller than the length P of the sheet  3 . Before the leading edge of the sheet  3  reaches the nip point N between the reverse-conveying rollers  26 , the reverse-conveying rollers  26  are driven to rotate in a forward rotation for conveying the paper  3  downward. At this time, the rotational speed of the reverse-conveying rollers  26  on the peripheral surfaces thereof is set to the velocity V 1 . Therefore, when the leading edge of the sheet  3  arrives at the nip point N, the sheet  3  maintains the velocity V 1  while being conveyed into the paper-retracting section  30 B. Thereafter, the trailing edge of the sheet  3  passes the fixing unit  23 . In other words, the entire part of the sheet  3  has passed the fixing unit  23 . Directly after the trailing edge of the sheet  3  passes the fixing unit  23 , the rotational speed of the reverse-conveying rollers  26  on the peripheral surface thereof, that is, the conveying velocity of the sheet  3  in the downward direction, is changed to the conveying velocity V 2  (mm/sec). Then, the trailing edge of the sheet  3  reaches the branch point B. After the trailing edge of the sheet  3  passes the branch point B and before the trailing edge of the sheet  3  reaches the nip point N of the reverse-conveying rollers  26 , the reverse-conveying rollers  26  begin rotating in reverse. Consequently, the conveying direction of the sheet  3  is reversed. At this time, the rotational speed of the reverse-conveying rollers  26  on the peripheral surface thereof, that is, the conveying velocity of the sheet  3  in the reverse direction, is maintained at the conveying velocity V 2  (mm/sec).