Abstract:
A medium clamping device includes: a first circularly-moving body having a circumferential surface harder than a recording medium, a longer length in a direction orthogonal to a circularly-moving direction than the recording medium in a first direction; a second circularly-moving body where the recording medium passes between the surfaces of the two circularly-moving bodies in a second direction crossing the first direction; a load applying section applying a load to at least one of the two circularly-moving bodies to clamp the recording medium; a belt member surrounding the surface of at least one of the two circularly-moving bodies, at a place outside an area touching the recording medium when the recording medium passes; and a belt-member-protecting member which is aligned with the belt member in a recording-medium-passing direction, includes a portion closer to a recording-medium-passing path than the belt member to protect the belt member from contacting the recording medium.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2009-280535, filed Dec. 10, 2009. 
       BACKGROUND 
       [0002]    (i) Technical Field 
         [0003]    The present invention relates to a medium clamping device and an image forming device. 
         [0004]    (ii) Related Art 
         [0005]    There is a medium clamping device provided in an image forming device. 
       SUMMARY 
       [0006]    According to an aspect of the invention, a medium clamping device includes: 
         [0007]    a first circularly moving body that has a circumferential surface moving circularly and harder than a recording medium with a surface where an image is formed, and that has a longer length in a direction orthogonal to a circularly moving direction of the circumferential surface than a length in a first direction of the surface of the recording medium; 
         [0008]    a second circularly moving body that has a circumferential surface moving circularly and harder than the recording medium, and that has a longer length in a direction orthogonal to a circularly moving direction of the circumferential surface of the second rotating body than the length in the first direction of the surface of the recording medium, where the recording medium passes between the circumferential surface of the first circularly moving body and the circumferential surface of the second circularly moving body in a second direction crossing the first direction; 
         [0009]    a load applying section that clamps, by applying a load to at least one of the first circularly moving body and the second circularly moving body, the recording medium by the load by using the first circularly moving body and the second circularly moving body; 
         [0010]    a belt member that surrounds the circumferential surface of at least one of the first circularly moving body and the second circularly moving body, at a place outside an area touching the recording medium when the recording medium passes, and that is softer than the circumferential surface and is thinner than the recording medium; and 
         [0000]    a belt member protecting member that is aligned with the belt member in a direction of passing for the recording medium, that includes a portion closer to a path of passing for the recording medium than the belt member, and that protects the belt member from contacting the recording medium. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
           [0012]      FIG. 1  is a schematic structural diagram that illustrates an embodiment of the image forming device according to the present invention; 
           [0013]      FIG. 2  is a perspective diagram of the deburring device that is an exemplary embodiment of the medium clamping device according to the present invention; 
           [0014]      FIG. 3  is a perspective diagram that illustrates a state in which the device main unit of the deburring device illustrated in  FIG. 2  is being drawn from the support section; 
           [0015]      FIG. 4  is a perspective view of the device main unit illustrated in  FIG. 3 ; 
           [0016]      FIG. 5  is a sectional view that illustrates a schematic structure of the inside of the device main unit illustrated in  FIG. 4 ; 
           [0017]      FIG. 6  is an enlarged sectional view of the edge of the paper sheet; 
           [0018]      FIG. 7  is a perspective view of the device main unit illustrated in  FIG. 4 , when viewed from another angle; 
           [0019]      FIG. 8  is a diagram for describing the structure of the roll support system; 
           [0020]      FIG. 9  is a diagram for describing the retraction movement of the roll; 
           [0021]      FIG. 10  is a diagram that illustrates the upper deburring roll and the lower deburring roll; 
           [0022]      FIG. 11  is a diagram that illustrates the belt member; 
           [0023]      FIG. 12  is a plane view that illustrates the positions of the guide member, the deburring roll and the auxiliary conveyance rolls in the device main unit; 
           [0024]      FIG. 13  is a perspective view of the guide member; 
           [0025]      FIG. 14  is an exploded perspective view of the support section illustrated in  FIG. 2 ; 
           [0026]      FIG. 15  is a perspective view of the support section in an assembled state. Further,  FIG. 16  is a perspective view of the support section in the assembled state when viewed from another angle; 
           [0027]      FIG. 16  illustrates a state in which the deburring driving motor and the gear are attached to the support section illustrated in  FIG. 15 ; 
           [0028]      FIG. 17  is a cross-sectional view for describing a structure of supporting the device main unit by using the support section; 
           [0029]      FIG. 18  is a graph that illustrates the burr heights of the paper sheet before and after the processing by the deburring device; 
           [0030]      FIG. 19  is a graph that illustrates the amount of scratches produced on the belt of the fixing device in the image forming device; 
           [0031]      FIG. 20  is a graph that illustrates the operating sound in each condition of the belt member; 
           [0032]      FIG. 21  is a graph that illustrates the ratio between the vibration in the frame of the deburring device and the vibration in the support frame of the image forming device, in the image forming device of the example 1; and 
           [0033]      FIG. 22  is a graph that illustrates the ratio between the vibration in the frame of the device main unit and the vibration in the support frame of the image forming device, in the comparative example. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Exemplary embodiments of the invention will be described below with reference to the drawings. 
       [Image Forming Device] 
       [0035]      FIG. 1  is a schematic structural diagram that illustrates an embodiment of the image forming device according to the present invention. 
         [0036]    An image forming device  1  illustrated in  FIG. 1  forms a toner image by forming an electrostatic latent image with a toner and developing the electrostatic latent image, and then transfers and fixes the toner image to a paper sheet, thereby finally forming an image of the fixed toner image on the paper sheet. Incidentally, this image forming device  1  accepts not only a paper sheet—i.e. a paper recording medium, but a resinous recording medium represented by an OHP sheet. However, the following description will be provided by using the paper recording medium as a representative example unless otherwise specified. The image forming device  1  is a tandem type of color printer in which six image forming sections  10 A,  10 B,  10 C,  10 D,  10 E and  10 F that respectively form images of mutually different colors are disposed in parallel. The image forming device  1  is capable of printing a single-colored image in a single-color mode and a color image formed by toner images of plural colors in a full-color mode. For example, among the six image forming sections  10 A through  10 F, the four image forming sections  10 C,  10 D,  10 E and  10 F correspond to yellow (Y), magenta (M), cyan (C) and black (K), respectively, and the remaining two image forming sections  10 A and  10 B correspond to spot colors except these YMCK colors. The spot colors include, for example, colors that are not easy to precisely express by the combination of YMCK, such as a color that represents a corporate color of a particular company, pastel colors, and transparent colors for luster. The image forming device  1  includes six toner cartridges  18 A,  18 B,  18 C,  18 D,  18 E and  18 F that contain toners of the colors corresponding to the image forming sections  10 A through  10 F, respectively. 
         [0037]    Since the six image forming sections  10 A through  10 F have similar structures, the image forming section  10 F corresponding to black will be described as representing these six image forming sections. The image forming section  10 F includes a photoreceptor  11 , a charging device  12  that charges the surface of the photoreceptor  11 , an exposure device  13  that irradiates the photoreceptor  11  with exposure light based on an image signal supplied externally, a developing device  14  that develops the surface of the photoreceptor  11  with a toner, and a primary transfer device  15  that transfers the toner image to an intermediate transfer belt  20 . The photoreceptor  11  has a surface in the shape of a cylinder and rotates in the direction of an arrow “a” around an axis of the cylinder. 
         [0038]    Further, the image forming device  1  includes the intermediate transfer belt  20  to which the toner image is transferred from the photoreceptor  11  of each of the image forming sections  10 A through  10 F, a secondary transfer device  30  that transfers the toner image from the intermediate transfer belt  20  to a paper sheet, a fixing device  40  that fixes the toner on the paper sheet, a decurler  50  that corrects a curl of the paper sheet, and a paper conveyance section  60  that conveys the paper sheet along a conveyance course  1  and a front-and-back inversion course R 2 . Furthermore, the image forming device  1  includes paper containers  71  and  72  that contain the paper sheet (s), a deburring device  80  that removes a burr of the paper sheet before image formation, a posture correcting section  73  that corrects the posture of the paper sheet. The image forming device  1  further includes a cooling device  74  that cools the paper sheet after the toner image is fixed, an output paper container  69  that receives the paper sheet after the image formation by the image forming device  1  is completed, and a controller  90  that controls each section of the image forming device  1 . 
         [0039]    The intermediate transfer belt  20  is a belt-shaped endless member supported by belt support rolls  21 ,  22  and  23 , and circulates in the direction of an arrow “b” that passes by the image forming sections  10 A through  10 F and the secondary transfer device  30  in this order. Here, the combination of the image forming sections  10 A through  10 F, the intermediate transfer belt  20 , the secondary transfer device  30  and the fixing device  40  is an example of the image forming section according to the present invention. 
         [0040]    The paper conveyance section  60  conveys the paper sheet along the conveyance course R 1  and the front-and-back inversion course R 2 . The paper conveyance section GO includes drawing rolls  61  and  62  that draw paper sheets from the paper containers  71  and  72 , respectively, a registration roll  64  that sends each of the paper sheets to the secondary transfer device  30  in timing for the transfer of the toner image by the secondary transfer device  30 , belt conveyance devices  65  that convey the paper sheet from the secondary transfer device  30  to the fixing device  40  while making the paper sheet cling to the outer surfaces of the belt conveyance devices  65 , an output roll  66  that outputs the paper sheet to the outside of the image forming device  1 , and conveyance rolls  68  that are respectively disposed along the conveyance course R 1  and the front-and-back inversion course R 2  and convey the paper sheets. Incidentally, in  FIG. 1 , only a part of the conveyance rolls  68  in the image forming device  1  is indicated by a reference character for easy viewing. 
         [0041]    The paper conveyance section  60  conveys the paper sheet from each of the paper containers  71  and  72  along the conveyance course R 1  passing through the deburring device  80 , the posture correcting section  73 , the secondary transfer device  30 , the fixing device  40 , the cooling device  74  and the decurler  50  sequentially. When double-sided printing is executed in the image forming device  1 , the paper conveyance section  60  conveys the paper sheet along the front-and-back inversion course R 2  diverging from the conveyance course R 1  and returning to the conveyance course R 1 . Subsequently, the paper sheet is turned back and then turned upside down in the front-and-back inversion course R 2 . The paper sheet after being turned upside down returns to the conveyance course R 1 , subsequently passes through the deburring device  80  and the posture correcting section  73  again, and the toner image is transferred by the secondary transfer device  30  to the reverse side of the paper sheet, namely the side to which the toner image is yet to be transferred. 
         [0042]    A basic operation of the image forming device  1  illustrated in  FIG. 1  will be described. The description will be provided by taking the image forming section  10 F corresponding to black (K) as a representative example. The photoreceptor  11  is driven to rotate in the direction of the arrow “a”, and a charge is applied to the surface of the photoreceptor  11  by the charging device  12 . The exposure device  13  forms an electrostatic latent image on the surface of the photoreceptor  11  by irradiating the photoreceptor  11  with exposure light based on an image signal supplied externally. To be more specific, the exposure device  13  forms the electrostatic latent image on the surface of the photoreceptor  11  by emitting the exposure light based on data corresponding to black in the image signal. The developing device  14  forms a toner image by developing the electrostatic latent image with a black toner. The developing device  14  of the image forming section  10 F is supplied with the toner by the toner cartridge  18 F. The photoreceptor  11  retains the toner image upon formation of the toner image. The toner image formed on the surface of the photoreceptor  11  is transferred to the intermediate transfer belt  20  by the primary transfer device  15 . 
         [0043]    The five image forming sections  10 A through  10 E corresponding to the colors except black also respectively form toner images corresponding to the respective colors in a manner similar to the image forming section  10 F corresponding to black. The intermediate transfer belt  20  is supported by the belt support rolls  21  through  23  and circulates in the direction of the arrow “b”. The image forming sections  10 A through  10 F transfer the toner images of the respective colors to the intermediate transfer belt  20  where the toner images are superimposed. In this way, the toner images according to the image data are formed on the intermediate transfer belt  20 , and the intermediate transfer belt  20  moves while retaining the toner images. 
         [0044]    Meanwhile, the paper sheets in the paper containers  71  and  72  are taken out by the drawing rolls  61  and  62 , and then conveyed along the conveyance course R 1  in the direction of an arrow “c” by the conveyance roll  68  and the registration roll  64  toward the secondary transfer device  300 . The burr removing device  80  disposed in the conveyance course R 1  removes a burr present at an edge of the paper sheet, and the posture and the position of the paper sheet are corrected by the posture correcting section  73 . The secondary transfer device  30  transfers the toner images on the intermediate transfer belt  20  to the paper sheet, by applying a bias potential for transfer between the intermediate transfer belt  20  and the paper sheet. The toner images are finally transferred to the paper sheet by the secondary transfer device  30  in this way. The paper sheet is then further conveyed in the direction of an arrow “d” by the belt conveyance devices  65 , and the toner images transferred to the surface of the paper sheet are fixed by the fixing device  40 . In this way, the image is formed on the paper sheet. The fixing device  40  has a fixing belt  410  to raise thermal capacity. The paper sheet with the surface where the image is formed is cooled by the cooling device  74 , and then a curl of the paper sheet is corrected by the decurler  50 . Subsequently, the paper sheet is output by the output roll  66 . 
         [0045]    When a double-sided printing mode is performed in the image forming device  1 , the paper conveyance section  60  conveys, along the front-and-back inversion course R 2 , a paper sheet after being conveyed along the conveyance course R 1 . Along the front-and-back inversion course R 2 , the paper conveyance section  60  turns the paper sheet upside down and then conveys the paper sheet along the conveyance course R 1  again. Meanwhile, when output of a paper sheet after being turned upside down is designated, although this is not the double-sided printing, the paper conveyance section  60  temporarily retracts, up to a midpoint of the front-and-back inversion course R 2 , the paper sheet after being conveyed along the conveyance course R 1 . Subsequently, the paper conveyance section  60  conveys the paper sheet in the reverse direction and then outputs the paper sheet. The output paper sheet is then laid in the output paper container  69 . 
       [Deburring Device] 
       [0046]      FIG. 2  is a perspective diagram of the deburring device that is an exemplary embodiment of the medium clamping device according to the present invention. 
         [0047]    The deburring device  80  illustrated in  FIG. 2  is disposed below the image forming sections  10 A,  10 B,  10 C,  10 D,  10 E and  10 F and the secondary transfer device  30  in the image forming device  1  illustrated in  FIG. 1 . The deburring device  80  is attached to a support frame F (see  FIG. 1 ) that supports the entire structure of the image forming device  1 . The deburring device  80  includes a device main unit  80 A and a support section  80 B that supports the device main unit  80 A. The deburring device  80  further includes a motor unit  800  (see  FIG. 16 ) that will be described later. 
         [0048]    The support section  80 B is attached to the support frame F of the image forming device  1  and supports the device main unit  80 A while allowing the device main unit  80 A to be removable from the image forming device  1 . A direction in which the device main unit  80 A conveys a paper sheet is referred to as a conveyance direction X (or, a passing direction X). Further, a direction that extends along the width of the conveyed paper sheet and crosses the conveyance direction X is referred to as a widthwise direction Y. Furthermore, a direction that crosses the conveyance direction X and the widthwise direction Y is referred to as a vertical direction Z. 
         [0049]      FIG. 3  is a perspective diagram that illustrates a state in which the device main unit of the deburring device illustrated in  FIG. 2  is being drawn from the support section. 
         [0050]    The support section  80 B is provided with rails  891  extending in the widthwise direction Y, and rails  811  extending in parallel with the rails  891  in the widthwise direction Y are provided at an upper part of the device main unit  80 A. The rails  891  of the support section  80 B are formed by bending both edges of the support section  80 B outwardly along the conveyance direction X. Hence, there are two rails  891  provided at both sides of the support section  80 B aligned along the conveyance direction X. The rails  811  of the device main unit  80 A are formed by bending inwardly upper parts at both sides of a frame  81 , which supports the entire structure of the device main unit  80 A, namely, by bending these upper parts in the direction of facing each other. The rails  811  of the device main unit  80 A are provided to correspond to the rails  891  of the support section  80 B. The rails  811  of the device main unit  80 A are on the rails  891  of the support section  80 B. The rails  811  of the device main unit  80 A move while sliding on the rails  891 , so that the device main unit  80 A moves in the widthwise direction Y along which the rails  891  extend. When, for example, removing a paper sheet jamming inside, an operator pulls the device main unit  80 A in the widthwise direction Y so that the device main unit  80 A is removed from the image forming device  1 . Further, the device main unit  80 A is attached to the image forming device  1  by being pushed in along the widthwise direction Y. The frame  81  that supports the structure of the device main unit BOA is provided with projections  812  that position the device main unit  80 A relative to the support section  80 B when the device main unit  80 A is attached. 
         [0051]    The support section  80 B supports the device main unit  80 A via a buffering mechanism incorporated therein, but the structure of the support section  802  will be described later and the device main body  80 A will be described first. 
       [Device Main Unit] 
       [0052]      FIG. 4  is a perspective view of the device main unit illustrated in  FIG. 3 .  FIG. 5  is a sectional view that illustrates a schematic structure of the inside of the device main unit illustrated in  FIG. 4 . 
         [0053]    The device main unit  80 A illustrated in  FIG. 4  and  FIG. 5  includes a pair of deburring rolls  82 A and  82 B, a pair of auxiliary conveyance rolls  83 A and a pair of auxiliary conveyance rolls  83 B, paper guide sections  84  and  85  that guide a paper sheet, a roll support system  86  that supports the deburring roll  82 A that is one of the pair of deburring rolls  82 A and  82 B, and the frame  81  that supports the structure of each part of the device main unit  80 A. Further, the device main unit  80 A includes a paper sensor S that detects the passage of a paper sheet. First, the device main unit  80 A allows the supplied paper sheet to pass between the auxiliary conveyance rolls  83 A and  83 B, while causing the paper guide section  84  to guide the supplied paper sheet. Subsequently, the device main unit BOA allows the paper sheet to pass between the deburring rolls  82 A and  82 B and then causes the paper guide section  85  to guide the paper sheet which is then output. 
         [0054]    The pair of deburring rolls  82 A and  82 B are disposed at positions to vertically sandwich the paper sheet and to face each other. The deburring rolls  82 A and  82 B function as a first circularly moving body (in other words, a first cylindrical body) and a second circularly moving body (in other words, a second cylindrical body), respectively, each having a circumferential surface that moves circularly. Of the deburring rolls  82 A and  82 B, the (lower) deburring roll  82 B disposed at a lower position is a drive roll that is driven to rotate by a deburring driving motor  801  (see  FIG. 16 ). The (upper) deburring roll  82 A is disposed at an upper position and serves as a following roll. When the upper deburring roll  82 A is in contact with the lower deburring roll  82 B, the upper deburring roll  82 A and the lower deburring roll  82 B are driven to rotate in the same direction at the positions where the paper sheet is held in between. Incidentally,  FIG. 4  illustrates a grip  821  that enables the operator to rotate the lower deburring roll  82 B manually so that a paper sheet is removed when a paper jam occurs. 
         [0055]    The pair of auxiliary conveyance rolls  83 A and the pair of auxiliary conveyance rolls  83 B are members that rotate while holding the paper sheet in between thereby conveying the paper sheet. Even in a state in which the deburring rolls  82 A and  82 B are away from each other, which will be described later, the paper sheet is conveyed by the auxiliary conveyance rolls  83 A and  83 B. Of the pair of auxiliary conveyance rolls  83 A and the pair of auxiliary conveyance rolls  83 B, the (lower) auxiliary conveyance rolls  83 B disposed at a lower position are drive rolls, whereas the (upper) auxiliary conveyance rolls  83 A disposed to face the lower auxiliary conveyance roll  83 B are following rolls. The lower auxiliary conveyance rolls  83 B are driven by the deburring driving motor  801  (see  FIG. 16 ) through a gear (not illustrated) linked to the lower deburring roll  82 B. 
         [0056]    The upper deburring roll  82 A is given a load directed to the lower deburring roll  82 B, so that when the paper sheet is clamped between the upper deburring roll  82 A and the lower deburring roll  82 B, the height of a burr present at an edge of the paper sheet is reduced. 
         [0057]      FIG. 6  is an enlarged sectional view of the edge of the paper sheet. 
         [0058]    When a paper sheet P is cut out of a material sheet, a burr B swelling due to the cutting is formed at the edge of the paper sheet P. The burr B is usually formed at the edge of each of four sides of the paper sheet. When the paper sheet having the burr is supplied to the secondary transfer device  30  and the fixing device  40 , the burr hits the intermediate transfer belt  20  and/or the fixing belt  410  of the fixing device  40 , causing scratches that lead to an image defect. When the paper sheet is clamped between the upper deburring roll  82 A and the lower deburring roll  82 B, the burr B of the paper sheet is pressed and a burr height H is reduced. Further, the crest of the burr B is deformed and smoothed. The paper sheet after passing between the upper deburring roll  82 A and the lower deburring roll  82 B in the deburring device  80  is supplied to the secondary transfer device  30  and the fixing device  40  and the image is formed. Since the paper sheet after the burr B is smoothed and the burr height H is reduced is applied to the secondary transfer device  30  and the fixing device  40  disposed downstream from the deburring device  80 , occurrences of scratches and image defects due to the scratches are reduced. 
       [Roll Support System] 
       [0059]    Next, a system of supporting the deburring rolls  82 A and  82 B will be described. 
         [0060]      FIG. 7  is a perspective view of the device main unit illustrated in  FIG. 4 , when viewed from another angle. Further,  FIG. 8  is a diagram for describing the structure of the roll support system. 
         [0061]    There is a bearing  822 B that is fixed to the frame  81  and supports a rotation shaft of the lower deburring roll  82 B. The upper deburring roll  82 A is given by the roll support system  86  a load directed to the lower deburring roll  82 B. The roll support system  86  includes a roll support arm  861  that supports a rotation shaft of the upper deburring roll  82 A, a spring member  862  that presses the roll support arm  861 , a bolt  863  that holds down the spring member  862 , a cam  864  that causes the roll support arm  861  to move up and down, and a retracting motor  865  (see  FIG. 8 ) that drives and thereby rotates the cam  864 . The roll support arm  861 , the spring member  862 , the bolt  863  and the cam  864  are each provided as a pair disposed on both sides of the device main unit  80 A and aligned in the widthwise direction Y. The roll support arm  861  supports the upper deburring roll  82 A at both sides. 
         [0062]    The roll support arm  861  is supported by a rotation shaft  861 P fixed to the frame  81 , and is rotatable relative to the frame  81  about the rotation shaft  861 P. There is a bearing  822 A that supports a rotation shaft of the upper deburring roll  82 A and is fixed to the roll support arm  861 . In other words, the upper deburring roll  82 A is supported by the roll support arm  861 . 
       [Load Applying Section] 
       [0063]    The spring member  862  is interposed between the head of the bolt  863  attached to the frame  81  and a pin  861 B provided at the roll support arm  861 . The spring member  862  is a compression spring, which is pressed down by the bolt  863  from above and thereby presses the roll support arm  861  downward via the pin  861 B. With this pressing-down force, the upper deburring roll  82 A supported by the roll support arm  861  is given the load directed to the lower deburring roll  82 B. 
         [0064]    In the roll support arm  861 , the distance between the pin  861 B receiving the load of the spring member  862  and the rotation shaft  861 P is longer than the distance between the upper deburring roll  82 A and the rotation shaft  861 P. To be more specific, the distance between the rotation shaft  861 P and the pin  861 B is about five times the distance between the rotation shaft  861 P and the upper deburring roll  82 A. For this reason, the upper deburring roll  82 A is given a heavy load by the leverage as compared with the load applied by the spring member  862  to press the roll support arm  861 . The size of the load is regulated based on the fastening by the bolt  863 , and a load of 55 kgw is applied between the upper deburring roll  82 A and the lower deburring roll  82 B. At this moment, the spring member  862  gives the pin  861 B a lighter load corresponding to the distance from the rotation shaft  861 P than the load applied to the upper deburring roll  82 A. Specifically, about one-fifth of the load applied to the upper deburring roll  82 A is given to the pin  861 B. In this way, the roll support arm  861 , the spring member  862 , the bolt  863  and the pin  861 B function as a load applying section, where the paper sheet is clamped between the upper deburring roll  82 A and the lower deburring roll  82 B by using the load applied to the upper deburring roll  82 A. Incidentally, as the load applying section, there may be adopted a structure in which the lower deburring roll  82 B in stead of the upper deburring roll  82 A is given a load or a structure in which both of these rolls are given a load. Alternatively, as the load applying section, there may be adopted a structure in which a load is directly applied to the shaft of the roll by using a spring member or the like without using the roll support arm although the size of the spring member is increased. 
       [Retraction Movement] 
       [0065]      FIG. 8  is a diagram that illustrates a clamping state in which the paper sheet is clamped between the upper deburring roll  82 A and the lower deburring roll  82 B. When the cam  864  is rotated starting from this clamping state, the upper deburring roll  82 A retracts from and is thereby away from the lower deburring roll  82 B. Subsequently, a mechanism to shift the state will be described. 
         [0066]    A cam follower  861 A is provided at an end of the roll support arm  861  opposite to the end where the rotation shaft  861 P is provided, and the cam  864  is in contact with the roll support arm  861  via the cam follower  861 A. The cam  864  is an eccentric cam and has a notch  864 B at the furthest position in a cam surface from a rotation shaft  864 A. The cam  864  is driven to rotate by the retracting motor  865  controlled by the controller  90  (see  FIG. 1 ). To be more specific, the retracting motor  865  drives the cam  864  by driving a gear  866  (see  FIG. 5 ) that shares the rotation shaft  864 A with the cam  864 . Also, a blade member  867  having a semicircle shape and corresponding to the displacement of the cam  864  is attached to the rotation shaft  864 A of the cam  864 . The blade member  867  represents the rotating posture of the cam  864  by rotating while interlocking with the cam  864 . A sensor  868  detects the passage of the blade member  867  and transmits a signal representing a detection result to the controller  90  (see  FIG. 1 ). The controller  90  causes the cam  864  to rotate based on the signal sent from the sensor  868 , thereby enabling the cam  864  to take a predetermined posture. 
         [0067]      FIG. 9  is a diagram for describing the retraction movement of the roll. 
         [0068]    When the retracting motor  865  drives and thereby rotates the cam  864 , the cam  864  pushes up the roll support arm  861  by resisting the pressing-down load applied by the spring member  862 . The blade member  867  rotates while interlocking with the cam  864 . After the passage of the blade member  867  is detected by the sensor  868 , the controller  90  causes the retracting motor  865  to stop rotating the cam  864 . As a result, the cam  864  is rotated a half turn and thereby contacts the cam follower  861 A at the furthest position from the center of rotation as illustrated in  FIG. 9 . When the cam follower  861 A is engaged in the notch  864 B formed at the furthest position from the center of rotation of the cam  864 , the cam  864  is in a stable state at this furthest position. In this way, the retracting motor  865 , the cam  864  and the roll support arm  861  function as a switching section that switches between a separated state in which the upper deburring roll  82 A and the lower deburring roll  82 B are separated from each other and the clamping state in which the upper deburring roll  82 A and the lower deburring roll  82 B clamp the recording medium. By the rotation of the cam  864 , the roll support arm  861  is rotated upward about the rotation shaft  861 P while being pushed up, and the upper deburring roll  82 A is retracted from the lower deburring roll  82 B. In the separated state, the upper deburring roll  82 A and the lower deburring roll  82 B are away from each other, preventing the paper sheet from being clamped. In the separated state, the space between the upper deburring roll  82 A and the lower deburring roll  82 B is sufficiently larger than the maximum thickness of the paper sheet processable by the image forming device  1  and thus, the paper sheet is not conveyed. At this moment, the paper sheet is conveyed by the auxiliary conveyance rolls  83 A and  83 B and passes between the upper deburring roll  82 A and the lower deburring roll  82 B. 
         [0069]    When the retracting motor  865  further rotates the cam  864  a half turn based on the controller  90  upon shifting from the separated state illustrated in  FIG. 9 , the cam  864  contacts the cam follower  861 A at the nearest position from the center of rotation. As a result, the upper deburring roll  82 A and the lower deburring roll  82 B enter the clamping state where the paper sheet is clamped in between (see  FIG. 8 ). Incidentally, in the clamping state illustrated in  FIG. 8 , the cam  864  and the cam follower  861 A may be separated from each other. 
         [0070]    The shift between the clamping state illustrated in  FIG. 8  and the separated state illustrated in  FIG. 9  is controlled by the controller  90  (see  FIG. 1 ). The controller  90  controls the movement of the retracting motor  865  by running a program stored in a memory (not illustrated) with a processor. The controller  90  acquires the type of the recording medium based on input operation of the operator or data supplied from the outside of the image forming device  1 , and also obtains a processing state of the recording medium in each element of the image forming device  1 , thereby determining either the clamping state or the separated state. In this way, the state of the upper deburring roll  82 A and the lower deburring roll  823  is switched depending on the type of the recording medium passing between the upper deburring roll  82 A and the lower deburring roll  823 . Incidentally, the controller  90  controls the entire image forming device  1 , but the controller  90  may be provided independently as a controller dedicated to the deburring device  80 . 
         [0071]    In the deburring device  80  of the present exemplary embodiment, the recording medium is a paper-sheet medium, and when the recording medium has a basis weight higher than a predetermined basis weight, the upper deburring roll  82 A and the lower deburring roll  82 B are in the separated state. To be more specific, when the basis weight is equal to or higher than 157 gsm, the upper deburring roll  82 A and the lower deburring roll  82 B are in the clamping state, whereas when the basis weight is lower than 157 gsm, the upper deburring roll  82 A and the lower deburring roll  82 B are in the separated state. Here, the basis weight of 157 gsm is equivalent to the thickness of about 150 μm of a general paper sheet. When the paper sheet whose basis weight is less than 157 gsm is clamped by the upper deburring roll  82 A and the lower deburring roll  823 , a wrinkle may be formed. On the other hand, the paper sheet having a basis weight of less than 157 gsm is softer than the paper sheet having a basis weight equal to or more than 157 gsm and therefore is unlikely to mar the members disposed downstream from the deburring device  80  such as the intermediate transfer belt  20  and the fixing belt  410  (see  FIG. 1 ). Accordingly, for the paper sheet whose basis weight is less than 157 gsm, the upper deburring roll  82 A and the lower deburring roll  82 B are in the separated state and the clamping is not carried out. 
         [0072]    Further, when a passing recording medium is made of paper and has a width less than 320 mm in the widthwise direction Y ( FIG. 2 ) or when the recording medium is a medium made of a resin material such as an OHP seat and a resin film, a wrinkle is unlikely to occur as compared to a paper sheet having a width equal to or more than 320 mm. Therefore, in this case, the upper deburring roll  82 A and the lower deburring roll  82 B in the deburring device  80  are in the clamping state, thereby reducing scratches on the members disposed downstream. 
         [0073]    Furthermore, in the image forming device  1  illustrated in  FIG. 1 , when an image is formed on each of both sides of a paper sheet, the paper sheet where the image is formed on one of the front and back sides is conveyed along the front-and-back inversion course R 2 . Subsequently, after the paper sheet turned upside down passes through the deburring device  80 , the image is formed on the other side. In this case, in order to prevent occurrence of a disturbance on the image as a result of clamping the paper sheet where the image is already formed on the one of the front and back sides between the upper deburring roll  82 A and the lower deburring roll  82 B, the upper deburring roll  82 A and the lower deburring roll  82 B are put in the separated state regardless of the type of paper sheet. 
       [Deburring Roll] 
       [0074]    Here, the upper deburring roll  82 A and the lower deburring roll  82 B will be described. 
         [0075]      FIG. 10  is a diagram that illustrates the upper deburring roll and the lower deburring roll.  FIG. 10  illustrates the upper deburring roll  82 A and the lower deburring roll  82 B in the postures disposed in the deburring device  80 , when viewed in the conveyance direction X. Further,  FIG. 10  illustrates the deburring driving motor  801  and a gear  803  that drive the lower deburring roll  82 B in a state in which the device main unit  80 A (see  FIG. 3 ) is attached to the support section  80 B. 
         [0076]    The upper deburring roll  82 A and the lower deburring roll  82 B include roll main sections  823 A and  823 B each having a circumferential surface to be in contact with the paper sheet, and the rotation shafts  824 A and  824 B, respectively. The rotation shafts  824 A and  824 B are fixed at both sides of the roll main section  823 A and at both sides of the roll main section  823 B, respectively, and supported by the bearings  822 A and  822 B (see  FIG. 7 ), respectively. The respective circumferential surfaces of the roll main sections  823 A and  823 B move circularly as the roll main sections  823 A and  823 B rotate. 
         [0077]    Each of the roll main sections  823 A and  823 B is made of a metal material harder than the paper sheet and is a hollow cylinder having a diameter of 35 mm. Specifically, each of the roll main sections  823 A and  823 B is made of stainless steel and has a nitrided surface. To be more specific, the surface of each of the roll main sections  823 A and  823 B is softnitrized. Each of the roll main sections  823 A and  823 B has a longer length in a direction orthogonal to a rotating direction R of the circumferential surface, namely in the widthwise direction Y in the present exemplary embodiment, than the length in the widthwise direction Y of the paper sheet conveyed between the upper deburring roll  82 A and the lower deburring roll  823 . 
         [0078]    The surface of each of the roll main sections  823 A and  823 B is made hard by the nitriding. For this reason, the surfaces of the roll main sections  823 A and  823 B are hard to deform and thus apply a high pressure to the burr when clamping the paper sheet. Therefore, as compared to a case in which the surface is not nitrided, the burr height of the paper sheet is further reduced. 
       [Belt Member] 
       [0079]    Of the upper deburring roll  82 A and the lower deburring roll  823 , the upper deburring roll  82 A is provided with a belt member  825  that is disposed on the circumferential surface of the roll main section  823 A and at a position outside an area D that touches the paper sheet. The belt member  825  surrounds the circumferential surface of the roll main section  823 A at each of both sides outside the area D that touches, when the paper sheet of the maximum size processable by the image forming device passes between the upper deburring roll  82 A and the lower deburring roll  823 , this paper sheet of the maximum size. Incidentally,  FIG. 10  illustrates the thickness of the belt member  825  in an expanded view for the description of the belt member  825 . 
         [0080]    The belt member  825  is softer than the roll main section  823 A and also thinner than a paper sheet having a minimum thickness (150 μm) among the paper sheets targeted for the deburring by the deburring device  80 . To be more specific, the belt member  825  is thinner than the thickness (about 100 μm) of a plain paper sheet widely used as copy paper. 
         [0081]    The belt member  825  is a tape having ends and a single layer that surrounds the circumferential surface of the roll main section  823 A. Both ends of the belt member  825  are close to each other across a border that is not orthogonal to the rotating direction R. To be more specific, both ends of the belt member  825  extend at an angle of 45 degrees relative to the rotating direction R. 
         [0082]      FIG. 11  is a diagram that illustrates the belt member. The belt member in a state before being attached to the upper deburring roll  82 A is illustrated in  FIG. 11 . Part (A) of  FIG. 11  is a plane view and Part (B) of  FIG. 11  is a side view. 
         [0083]    The belt member  825  includes a base layer  8251  made of a resin material and an adhesive layer  8252  that adheres this base layer to the circumferential surface. Specifically, the base layer  8251  is a polyimide tape having a thickness of 50 μm, and the adhesive layer  8252  is an adhesive having a thickness of 30 μm. Therefore, the thickness of the entire belt member  825  is 80 μm. Incidentally, as the material of the base layer, polyurethane or polycarbonate that are softer than the roll main section  823 A may be employed. However, the base layer made of polyimide provides lower movement sound and higher friction durability than those of other resin materials. In addition, by making the base layer made of polyimide have the thickness of 50 μm, peeling of the end due to hardness and elasticity of the base layer when being wound around the roll is prevented, as compared to a case where the thickness is made equal to or larger than 50 μm. 
         [0084]    When no paper sheet is clamped between the roll main section  823 A of the upper deburring roll  82 A and the roll main section  823 B of the lower deburring roll  82 B in the clamping state, the belt member  825  is clamped therebetween and thus, the roll main section  823 A and the roll main section  823 B do not directly contact each other. When the operation of deburring the paper sheet is performed by the deburring device  80 , the upper deburring roll  82 A and the lower deburring roll  82 B clamp the paper sheet in between, so that the distance between the respective circumferential surfaces is extended according to the thickness of the paper sheet. After the tail of the paper sheet passes between the upper deburring roll  82 A and the lower deburring roll  82 B, the upper deburring roll  82 A returns toward the lower deburring roll  82 B due to the load applied by the spring member  862  (see  FIG. 8 ). At this moment, a shock occurs due to collision, and if the respective hard circumferential surfaces of the roll main section  823 A and the roll main section  823 B hit each other, a large shock is produced, causing loud impulsive sound. Moreover, when the shock is transmitted to the image forming sections  10 A,  10 B,  10 C,  10 D,  10 E and  10 F as well as the secondary transfer device  30  of the image forming device, the image is disturbed. 
         [0085]    When the belt member  825  is provided, after the tail of the paper sheet passes between the upper deburring roll  82 A and the lower deburring roll  82 B, the roll main section  823 B of the lower deburring roll  82 B hits the belt member  825  of the roll main section  823 A of the upper deburring roll  82 A. A shock occurring here is absorbed by the belt member  825  that is softer than the upper deburring roll  82 A and the lower deburring roll  82 B. 
         [0086]    The belt member  825  is thinner than the paper sheet having the maximum thickness. Therefore, the paper sheet is clamped between the upper deburring roll  82 A and the lower deburring roll  82 B by the applied load regardless of the belt member  825  when the paper sheet passes therebetween and thus, the burr is corrected without a hitch. 
         [0087]    In a state in which there is no passing paper sheet, the upper deburring roll  82 A rotates while causing the belt member  825  to touch the roll main section  823 B of the lower deburring roll  82 B. Here, since both ends of the belt member  825  are close to each other across the border that is not orthogonal to the rotating direction R, the roll main section  823 B of the lower deburring roll  82 B smoothly rolls across the belt member  825  from one end to the other end of the belt member  825 . Therefore, vibrations accompanying the rotation of the lower deburring roll  82 B in the state of no recording medium are reduced as compared to a case in which these both ends are orthogonal to the rotating direction R. 
       [Paper Guide Section] 
       [0088]    Subsequently, the paper guide sections  84  and  85  will be described. 
         [0089]      FIG. 12  is a plane view that illustrates the positions of the guide member, the deburring roll and the auxiliary conveyance rolls in the device main unit.  FIG. 12  illustrates only the paper guide sections  84  and  85 , the upper deburring roll  82 A, and the upper auxiliary conveyance rolls  83 A. 
         [0090]    The paper guide sections  84  and  85  are disposed upstream and downstream from the upper deburring roll  82 A, respectively, in the conveyance direction X. The structures of the paper guide section  84  disposed upstream and the paper guide section  85  disposed downstream are the same except the length in the conveyance direction X. The paper guide section  84  includes a pair of flat members  841  and protruding members  843  and  844  interposed between the pair of flat members  841 . 
         [0091]      FIG. 13  is a perspective view of the guide member.  FIG. 13  illustrates, of the two paper guide sections  84  and  85 , the paper guide section  85  disposed downstream in the conveyance direction X. 
         [0092]    The paper guide section  85  includes a pair of flat members  851  and  852  and protruding members  853  and  854  interposed between the flat members  851  and  852 . 
         [0093]    Each of the flat members  851  and  852  is in the shape of a plate expanding along the front and back surfaces of the paper sheet passing between the upper deburring roll  82 A and the lower deburring roll  82 B. A path D where the paper sheet is to pass is provided between the pair of flat members  851  and  852  that sandwich the path D in the vertical direction Z crossing the front and back surfaces of the paper sheet. The protruding members  853  and  854  are flat members that fill the space between the flat members  851  and  852  at both ends in the widthwise direction Y of the flat members  851  and  852 , thereby keeping the distance between the pair of flat members  851  and  852  uniform. 
         [0094]    Returning to  FIG. 12 , the description will be continued. 
         [0000]    Along the path D, the paper sheet is guided by the paper guide section  84  thereby passing between the pair of auxiliary conveyance rolls  83 A and the pair of auxiliary conveyance rolls  83 B and then, upon passing between the pair of deburring rolls  82 A and  82 B the paper sheet is guided by the paper guide section  85  and output. 
         [0095]    Here, the pair of protruding members  843  and  844  provided in the paper guide section  84  are aligned with the pair of belt members  825  in the conveyance direction X in which the paper sheet passes, and disposed at positions protruding beyond the pair of belt members  825  relative to the path D. In addition, each of the protruding members  843  and  844  has a downstream end and an upstream end in the conveyance direction X, and the downstream end protrudes closer to the path D than the upstream end. For this reason, the position of the paper sheet entering while deviating from the path D is corrected toward the path D. 
         [0096]    For example, when removing a paper sheet jamming in the deburring device  80 , the operator may pull a protruding part of the paper sheet from the deburring device  80 . However, the paper sheet may not be pulled in the conveyance direction X and may rather be pulled toward the operator diagonally relative to the conveyance direction X. In this case, the paper sheet hits the protruding members  843  and  844  protruding beyond the belt members  825 , thereby avoiding contact with the belt members  825 . Even in a case where the deburring device  80  normally operates, when the paper sheet is supplied to the deburring device  80  while taking a posture tilting relative to the conveyance direction X, the paper sheet hits the protruding members  843  and  844  protruding further than the belt members  825 , thereby avoiding contact with the belt members. Therefore, there is avoided such a situation that the belt members  825  softer than the deburring rolls  82 A and  82 B are scratched or damaged as a result of contact with the paper sheet. 
       [Support Section] 
       [0097]    Next, the support section  80 B that supports the device main unit  80 A will be described. 
         [0098]      FIG. 14  is an exploded perspective view of the support section illustrated in  FIG. 2 . 
         [0099]    The support section  80 B has a fixed section  87 , buffer members  88  attached to the fixed section  87 , and a rail member  89  attached to the buffer members  88 . 
         [0100]    The fixed member  87  is fixed to the support frame F of the image forming device  1 . To be more specific, when fixing pieces  871  and  872  provided at both ends of the fixed section  87  and extending in the widthwise direction Y are screwed on the support frame F, the fixed section  87  is fixed to the support frame F. 
         [0101]    There are four buffer members  88  dispersed and disposed at four points on the fixed section  87 . Each of the buffer members  88  has a structure in which a pair of fixing plates  882  and  883  for screwing a buffer material  881  made of urethane resin are respectively adhered to the bottom and the top of the buffer material  881 . The buffer material  881  has a height of 15 mm. In  FIG. 14 , the reference characters  881  through  883  are provided for only one of the four buffer members  88  for easy viewing. 
         [0102]    The rail member  89  is a member attached to the buffer member  88 , and is disposed and screwed on the fixing plate  883  of the buffer member  88 . The rail member  89  includes the rails  891  extending in the widthwise direction Y. Although the rail member  89  is provided with the rails  891  at both sides in the conveyance direction X,  FIG. 14  illustrates only one of the rails  891 . 
         [0103]      FIG. 15  is a perspective view of the support section in an assembled state. Further,  FIG. 16  is a perspective view of the support section in the assembled state when viewed from another angle.  FIG. 16  illustrates a state in which the deburring driving motor and the gear are attached to the support section illustrated in  FIG. 15 . 
         [0104]    The support section  80 B illustrated in  FIG. 15  is assembled by laying and attaching the rail member  89  on and to the buffer members  88  fastened to the fixed section  87  illustrated in  FIG. 14 . Further, when the motor unit  80 C is attached to the rail member  89  of the support section  80 B illustrated in  FIG. 15 , the state illustrated in  FIG. 16  is realized. The motor unit  80 C illustrated in  FIG. 16  includes the deburring driving motor  801 , a fixing frame  802  that fixes the deburring driving motor  801  to the rail member  89 , and the gear  803  that transmits a driving force of the deburring driving motor  801  to the lower deburring roll  82 B. The motor unit  80 C is fixed to the rail member  89  of the support section  80 B through the fixing frame  802 . The rail member  89  of the support section  80 B has positioning sections  892  that position the device main unit  80 A (see  FIG. 4 ) relative to the rail member  89 . Specifically, the positioning sections  892  are holes formed in the rail member  89 . 
         [0105]    The support section  80 B illustrated in  FIG. 16  is attached in the image forming device  1  by screwing the fixing pieces  871  and  872  of the fixed section  87  to the support frame F. 
         [0106]    To attach the device main unit  80 A to the support section  80 B, the operator places the edges of the pair of rails  811  (see  FIG. 4 ), which are provided at the upper part of the frame  81  of the device main unit  80 A, on the edges of the pair of rails  891  of the support section  803 , respectively. Afterwards, as illustrated in  FIG. 3 , the device main unit  80 A is pushed in by the operator and thereby being attached. The gear  803  of the motor unit  80 C is connected to the lower deburring roll  82 B. 
         [0107]    The frame  81  of the device main unit  80 A is provided with the projections  812  ( FIG. 3 ) protruding in the widthwise direction Y. When the device main unit  80 A is attached, the projections  812  are respectively engaged in the positioning sections  892  provided in the rail member  89  so that the device main unit  80 A is positioned relative to the rail member  89 . 
         [0108]    As already described above, the shock produced when the roll main sections  823 A and  823 B are in the clamping state is absorbed and thus reduced by the belt member  825  of the roll main section  823 A. However, when a residual shock as not being absorbed and/or vibration due to the movements of the device main unit  80 A other than this shock are transmitted to the image forming sections  10 A,  10 B,  10 C,  10 D,  10 E and  10 F and the secondary transfer device  30 , the image is disturbed. The support section  803  alleviates the transmission of the shock and vibration by using the buffering mechanism incorporated therein. Incidentally, in the following description, the vibration will be included in the shock, unless otherwise specified. 
         [0109]      FIG. 17  is a cross-sectional view for describing a structure of supporting the device main unit by using the support section. 
         [0110]    As illustrated in  FIG. 17 , in the state that the device main unit  80 A is attached to the support section  80 B, the buffer members  88  are disposed on the fixed section  87  fixed to the support frame F (see  FIG. 16 ) of the image forming device  1 , and the rail member  89  is disposed on the buffer members  88 . Further, the rails  811  of the device main unit  80 A are disposed on the rails  891  of the rail member  89 . If there is adopted such a structure that the rail member is hung under the fixed member through the buffer members, there is a possibility that the buffer members may break due to a tension by the weight of the device main unit, and an adhered part may come off. In contrast, the structure of supporting the device main unit  80 A illustrated in  FIG. 17  is made stronger, as compared to the structure in which the rail member is hung under the fixed member through the buffer members. Furthermore, as already described above, the device main unit  80 A is positioned relative to the rail member  89  by the projections  812  (see  FIG. 3 ) and the positioning sections  892  ( FIG. 16 ), and the motor unit  80 C also is fixed to the support section  80 B. 
         [0111]    The transmission of the shock occurring in the device main unit  80 A from the rail member  89  to the fixed section  87  is reduced by the buffer members  88 . Therefore, the shock transmitted from the device main unit  80 A to the image forming sections  10 A,  10 B,  10 C,  10 D,  10 E and  10 F and the secondary transfer device  30  is reduced. As a result, disturbance of the image formed on the paper sheet due to the shock is reduced. Incidentally, the buffer material  881  made of urethane resin has been described, but rubber or a spring other than the urethane resin may be employed to make the buffer material. 
       Example 
       [0112]    An image forming device of an example based on the exemplary embodiment is made, and characteristics are measured. 
       [Measurement of Burr Height] 
       [0113]    A paper sheet is passed in the deburring device, and the burr height H ( FIG. 6 ) of a burr of the paper sheet before passing and that after passing are measured. 
         [0114]      FIG. 18  is a graph that illustrates the burr heights of the paper sheet before and after the processing by the deburring device. 
         [0115]    As illustrated in the graph, the burr height after the deburring processing is reduced as compared to the burr height before the deburring processing. 
       [Evaluation of Scratch on Member in Later Stage] 
       [0116]    Subsequently, the amount of scratches produced on the fixing belt  410  of the fixing device  40  (see  FIG. 1 ) disposed downstream from the deburring device is checked for a case in which the deburring processing is performed by the deburring device and a case in which the deburring processing is not performed. The amount of scratches produced on the belt is evaluated by viewing from 0 (no scratch is found) to 5 grades in steps of 0.5. 
         [0117]      FIG. 19  is a graph that illustrates the amount of scratches produced on the belt of the fixing device in the image forming device. A horizontal axis of the graph indicates the number of paper sheets processed by the image forming device, and the unit of the numbers is 1,000 sheets (kPV). 
         [0118]    As illustrated in  FIG. 19 , when the deburring processing is not carried out (without deburring), the grade expressing the amount of scratches produced on the belt of the fixing device at a stage where 5,000 sheets are processed is increased to 2, and the grade at a stage where 10,000 sheets are processed is increased to 4. On the other hand, when the deburring processing is carried out (with deburring), the grade does not reach 2 even at a stage where 40,000 sheets are processed. 
       [Measurement of Noise in Bach Condition of Belt Member] 
       [0119]    Next, influence of the belt member  825  provided in the upper deburring roll  82 A on operating sound and durability of the belt member are examined. 
         [0120]    For an image forming device of an example 1 based on the exemplary embodiment, steady sound at the time of the deburring operation is measured. Incidentally, the belt member in the example 1 includes a base layer made of polyimide and having a thickness of 50 μm and an adhesive layer having a thickness of 30 μm. Further, an example 2 is made by employing a base layer having the same thickness as that in the example 1 and made of another material, namely polyurethane. Furthermore, an example 3 is made by employing a base layer made of polyimide and having a thickness of 70 μm. Still further, an example 4 is made by employing a base layer having the same thickness as that in the example 3 and made of polycarbonate. In each of the examples 3 and 4, in order to make the height of the belt member less than the thickness of the target recording medium, the adhesive layer is made to have a thickness of 10 μm. Still furthermore, a comparative example having no belt member (tape) is prepared. These examples 1 through 4 and the comparative example are operated, and the steady sound is measured. 
         [0121]      FIG. 20  is a graph that illustrates the operating sound in each condition of the belt member. 
         [0122]    As illustrated in the graph, as compared to the comparative example having no belt member, the level of the steady sound is reduced in each of the examples 1 through 4 each having the belt member. 
       [Durability Test of Belt Member] 
       [0123]    Here, durability of the belt member in each of the examples 1 through 4 is examined. As the durability, adhesive strength and abrasion resistance of the belt member are measured. 
         [0124]    The adhesive strength in each of the examples 1 through 4 is measured as follows. After the belt member is adhered to the upper deburring roll, the belt member is left alone for 24 hours and then the adhesive strength at the time when the belt member is peeled by a 90 degrees peeling method is measured. The results obtained by measuring the adhesive strength are as follows. 
         [0125]    Example 1 (polyimide 50 μm): 300 gw 
         [0126]    Example 2 (polyurethane 50 μm): 330 gw 
         [0127]    Example 3 (polyimide 70 μm): 100 gw 
         [0128]    Example 4 (polycarbonate 70 μm): 150 gw 
         [0129]    Further, as for the example 3, after the belt member is adhered to the upper deburring roll and then the belt member is left alone for 24 hours, pealing at an end of the roll is found. 
         [0130]    In the measurement of the abrasion resistance, a load test is run on the friction. Specifically, in the deburring device  80  in each of the examples 1 through 4, the upper deburring roll provided with the belt member is prevented from rotating and given a load of 55 kgw. In this state, when the lower deburring roll is driven to rotate, the lower deburring roll rotates while rubbing against a single spot of the belt member. 
         [0131]    As a result, the base material of the belt member in the example 2 (polyurethane 50 μm) is damaged after 60 minutes and the base material of the belt member in the example 4 (polycarbonate 70 μm) is damaged after 50 minutes, each following the start of the rotation of the lower deburring roll. In the example 1 (polyimide 50 μm) and the example 3 (polyimide 70 μm), no damage is found even after a lapse of 12 hours following the start of the rotation of the lower deburring roll. 
       [Transmission Property of Shock] 
       [0132]    Next, there is measured transmission property of a shock transmitted from the device main unit  80 A to the support frame F of the image forming device  1 , under a condition with the buffer members  88  and a condition without the buffer members  88 . 
         [0133]    In the image forming device of the example 1, a sensor that detects vibration is attached to each of the frame  81  (see  FIG. 4 ) of the deburring device and the support frame F (see  FIG. 16 ) of the image forming device  1 , and then a shock is applied to the frame  81  of the deburring device. Subsequently, a ratio between the amplitude of the vibration due to the shock detected by one of the sensors and that of the other sensor is measured as a gain of a transmission function. Also, the ratio between the vibrations is measured in a comparative example in which the rail member  89  is directly fixed to the fixed section  87  without using the buffer members  88 . 
         [0134]      FIG. 21  is a graph that illustrates the ratio between the vibration in the frame of the deburring device and the vibration in the support frame of the image forming device, in the image forming device of the example 1. Further,  FIG. 22  is a graph that illustrates the ratio between the vibration in the frame of the device main unit and the vibration in the support frame of the image forming device, in the comparative example. A horizontal axis of the graph in each of  FIG. 21  and  FIG. 22  indicates the frequency (component) of the vibration, and a vertical axis indicates the ratio (gain) of the vibration in the support frame of the image forming device to the vibration in the frame of the device main unit. 
         [0135]    The ratio (gain) of the vibration in the image forming device of the example 1 illustrated in the graph of  FIG. 21  is reduced to be less than the ratio of the vibration in the comparative example illustrated in the graph of  FIG. 22 , in any of the frequencies in the graph. Further, the ratio of the vibration in the example 1 is smaller than 1 in any of the frequencies in the graph. It is found that the transmission of the shock from the main unit of the deburring device to the support frame of the image forming device is alleviated by providing the buffer members  88 . 
         [0136]    Incidentally, in the exemplary embodiment, the tandem type of color printer is described as an example of the image forming device, but the image forming device is not limited to this example and may be, for example, a printer dedicated to monochrome and having no intermediate transfer belt. 
         [0137]    Further, in the exemplary embodiment, the printer is described as an example of the image forming device, but the image forming device is not limited to this example and may be, for example, a copier or a facsimile. 
         [0138]    Furthermore, in the exemplary embodiment, the combination of the charging device, the exposure device and the developing device is described as an example of the image forming section, but the image forming section is not limited to this example and may be, for example, an element that causes a toner to directly adhere to a position corresponding to an image on an image retainer by aiming that position. 
         [0139]    The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The exemplary embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.