Abstract:
A fixing device is provided with a fixing roller, a peeling claw that peels a recording paper from the fixing roller, a peeling claw holder that rotatably supports the peeling claw, and a support member that movably supports the peeling claw holder to enable the peeling claw to retract by moving apart from the fixing roller, wherein not less than two directions are set as retracting directions of the peeling claw holder to be moved when the peeling claw is caused to retract by moving apart from the fixing roller.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2010-018806 filed in Japan on Jan. 29, 2010, the entire contents of which are herein incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to fixing devices that fix toner images formed on paper, and to image forming apparatuses including the same. 
         [0003]    This type of fixing device is applied in image forming apparatuses that use methods such as electrography, electrostatic recording, and magnetography or the like, and sandwich between a pair of fixing rollers a paper (such as plain paper, electrostatic recording paper, and photographic papers or the like) on which a toner image has been formed, thereby applying heat and pressure to fix the toner image onto the paper. 
         [0004]    In these fixing devices, the paper sometimes winds around the fixing roller, and therefore the tip of a peeling claw is kept in contact with the fixing roller such that any paper that has wound around the fixing roller is peeled off by this peeling claw. 
         [0005]    However, when a paper blockage (jam) occurs in the vicinity of the peeling claw of the fixing roller and transport of the paper stacks up, the paper sometimes strongly pushes the peeling claw against the surface of the fixing roller, thereby damaging the surface of the fixing roller or damaging the peeling claw. 
         [0006]    For this reason, in JP 2002-14565A and JP 2002-145503A, a holder of the peeling claw (separation claw) is movably supported along a groove, and when the holder is pressed by the paper during a jam, the holder moves along the groove such that the separation claw retracts by moving apart from the fixing roller. 
         [0007]    However, in both JP 2002-14565A and JP 2002-145503A, the movement trajectory of the holder when the separation claw holder moves along the groove is on a single line, and the movement direction of the holder is prescribed to a single direction, and therefore sometimes the tip of the separation claw cannot retract when the holder or the separation claw is being pressed by the jammed paper, and at this time the tip of the separation claw strongly presses against the surface of the fixing roller, thereby causing damage to the surface of the fixing roller or damage to the peeling claw. 
         [0008]    Accordingly, the present invention has been devised in consideration of the foregoing conventional problems, and it is an object thereof to provide a fixing device and an image forming apparatus including the same in which the peeling claw can be reliably retracted from the surface of the fixing roller during a jam. 
       SUMMARY OF THE INVENTION 
       [0009]    In order to address these issues, a fixing device according to the present invention is provided with a fixing roller, a peeling claw that peels a recording paper from the fixing roller, a peeling claw holder that rotatably supports the peeling claw, and a support member that movably supports the peeling claw holder to enable the peeling claw to retract by moving apart from the fixing roller, wherein not less than two directions are set as retracting directions of the peeling claw holder to be moved when the peeling claw is caused to retract by moving apart from the fixing roller. 
         [0010]    With the present invention, the peeling claw holder is movably supported in two or more directions (for example, two directions or a range contained between the two directions) so that the peeling claw retracts by moving apart from the fixing roller, and therefore when the peeling claw or the peeling claw holder is pressed by a blocked paper, the peeling claw holder can readily move in two or more directions (two directions or a wide range), and the peeling claw reliably retracts from the fixing roller, thus enabling a situation to be avoided in which the claw tip of the peeling claw strongly presses against the surface of the fixing roller. 
         [0011]    Furthermore, in the fixing device according to the present invention, the peeling claw holder may be provided with a pin that supports the peeling claw, the support member may be provided with a guide groove that guides the pin, and the peeling claw holder may be movably supported in the support member by the pin. 
         [0012]    Due to the guide groove of the support member, when the peeling claw retracts by moving apart from the fixing roller, the peeling claw holder can be guided in two or more directions. 
         [0013]    For example, an edge of the guide groove may be provided with opposing portions that are not parallel, and the peeling claw holder may be caused to move in the retracting directions by the pin being guided along the opposing portions. 
         [0014]    Furthermore, the fixing device according to the present invention may be provided with a spring that applies a biasing force to the peeling claw holder in a direction in which a claw tip of the peeling claw approaches the fixing roller. 
         [0015]    In this way, the tip of the peeling claw is positioned approaching the surface of the fixing roller. 
         [0016]    Furthermore, to address the above-described issues, an image forming apparatus according to the present invention is provided with a fixing device according to the present invention described above. Thus, an operation and effect is achieved equivalent to the fixing device according to the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a cross-sectional view showing an enlargement of principal portions of an image forming apparatus in which one embodiment of a fixing device according to the present invention has been applied. 
           [0018]      FIG. 2  is a perspective view showing multiple peeling claws and a support frame in a fixing device according to the present embodiment. 
           [0019]      FIG. 3  is an exploded perspective view showing a support structure of a peeling claw. 
           [0020]      FIG. 4  is constituted by  FIG. 4A  and  FIG. 4B , which are perspective views showing the support structure of the peeling claw as viewed from above and below respectively. 
           [0021]      FIG. 5  is constituted by  FIG. 5A ,  FIG. 5B , and  FIG. 5C , which are a lateral view, a top view, and a front view showing the support structure of the peeling claw. 
           [0022]      FIG. 6  is constituted by  FIG. 6A  and  FIG. 6B , which are diagrams showing movement of the peeling claw supported by the peeling claw holder. 
           [0023]      FIG. 7  is constituted by  FIG. 7A ,  FIG. 7B , and  FIG. 7C , which are diagrams showing movement of the peeling claw holder supported by the support casing and the peeling claw. 
           [0024]      FIG. 8  is constituted by  FIG. 8A ,  FIG. 8B , and  FIG. 8C , which are diagrams showing another movement of the peeling claw holder supported by the support casing and the peeling claw. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0025]    Hereinafter, embodiments of the present invention are described in detail with reference to the accompanying drawings. 
         [0026]      FIG. 1  is a cross-sectional view showing an enlargement of principal portions of an image forming apparatus in which one embodiment of a fixing device according to the present invention has been applied. 
         [0027]    This image forming apparatus  1  is based on an electrographic method and is provided with components such as a photosensitive drum  2 , a transfer belt  3 , and a fixing device  4 . The photosensitive drum  2  has a photosensitive layer on its surface and is rotationally driven in the direction of arrow A at a constant rotational velocity. Accompanying rotation of the photosensitive drum  2 , the surface of the photosensitive drum  2  is charged uniformly to a predetermined electric potential by a charging device (not shown in drawings), an electrostatic latent image is formed on the surface of the photosensitive drum  2  by an exposure device (not shown in drawings), and the electrostatic latent image on the surface of the photosensitive drum  2  is developed into a toner image by a development device (not shown in drawings). 
         [0028]    The transfer belt  3  is driven in the direction of arrow B at the same velocity as the surface velocity of the photosensitive drum  2  and presses against the photosensitive drum  2  so that a nip region forms therebetween. A paper that is transported in from there-below is introduced to the nip region, and a toner image on the surface of the photosensitive drum  2  is transferred onto the paper while the paper is transported in the nip region. A high voltage transfer bias (a high voltage (+) that has opposite polarity to the charge polarity (−) of the toner) is applied to the transfer belt  3  to achieve transfer of the toner image. 
         [0029]    The paper is transported upward from the photosensitive drum  2  (downstream in the transport direction) and guided to the fixing device  4 . The fixing device  4  is provided with a pair of fixing rollers, and this pair of fixing rollers is constituted by a heating roller  11  and a pressure roller  12 . The heating roller  11  and the pressure roller  12  press against each other to form a nip region therebetween, and one of these is rotationally driven and the other idly rotates. The paper that is transported from upstream in the transport direction is sandwiched by the heating roller  11  and the pressure roller  12  and subjected to heat and pressure in the nip region between the heating roller  11  and the pressure roller  12 , thereby fixing the toner image onto the paper. 
         [0030]    This paper is transported further upward through a transport route  5  and discharged into a discharge tray (not shown in drawings) or the like. 
         [0031]    In addition to the heating roller  11  and the pressure roller  12 , the fixing device  4  according to the present embodiment is provided with components such as an external heating roller  13  that heats the pressure roller  12 , a cleaning device  14  for removing toner that has adhered to the surface of the heating roller  11 , and peeling claws  15  and  16 , which are arranged near the surfaces of and correspond to the heating roller  11  and the pressure roller  12  respectively. 
         [0032]    The heating roller  11  includes an inbuilt heater  17  and is heated by this inbuilt heater  17 . The surface of the pressure roller  12  is heated by the external heating roller  13 . 
         [0033]    Furthermore, the heating roller  11  and the pressure roller  12  are rollers having a three-layer construction and are constituted by a core of a metal such as iron, stainless steel, aluminum, or copper or an alloy of any of these, an elastic layer of a silicone rubber or the like on a surface of the core, and further still a mold release layer thereon of PFA or PTFE or the like. 
         [0034]    The cleaning device  14  is provided with a feed-out roller  22  onto which is wound a thin web sheet  21  permeated with an oil (silicone oil) or the like, a take-up roller  23  to which the leading edge of the web sheet  21  is connected, and a pressing roller  24  that presses the web sheet  21  between the feed-out roller  22  and the take-up roller  23  onto the heating roller  11 , and residual toner adhering to the surface of the heating roller  11  is wiped off and removed by the web sheet  21  being pressed against the surface of the heating roller  11  by the pressing roller  24 . Furthermore, the feed-out roller  22  and the take-up roller  23  are intermittently rotated by a fixed amount so that the web sheet  21  is fed out and taken up by the fixed amount, thereby renewing the portion of that web sheet  21  that presses against the surface of the heating roller  11 . 
         [0035]    The tips of the peeling claws  15  and  16  contact the surface of the heating roller  11  and the surface of the pressure roller  12  respectively, and peel off from the heating roller  11  or the pressure roller  12  any paper that has wound onto the heating roller  11  or the pressure roller  12 . 
         [0036]    Here, suppose a paper blockage (jam) occurs in the vicinity of the peeling claw  15  (or  16 ) and the paper stacks up so that the surface of the heating roller  11  (or the pressure roller  12 ) becomes damaged or the peeling claw  15  (or  16 ) becomes damaged when the peeling claw  15  (or  16 ) is strongly pressed against the surface of the heating roller  11  (or the pressure roller  12 ) by the paper. 
         [0037]    In particular, since papers tend to wind onto the heating roller  11  since it contacts the surface of the paper on which the toner image is transferred, the occurrence of such a situation is a matter of concern. 
         [0038]    Accordingly, to address these problems, the present embodiment is provided with a configuration in which the peeling claw  15  is movably supported so that the peeling claw  15  on the heating roller  11  side retracts by moving apart from the heating roller  11 , thereby reliably avoiding a situation in which the tip of the peeling claw  15  (see claw tip  15   a  below) strongly presses against the surface of the heating roller  11  during the occurrence of a jam. 
         [0039]    Next, detailed description is given regarding a support structure of the peeling claw  15  that is capable of retracting by moving apart from the heating roller  11  by way of a peeling claw holder  31  (see below). 
         [0040]      FIG. 2  shows multiple peeling claws  15  arranged in a row. In  FIG. 2 , a support frame  25  is provided along the heating roller  11  (specifically, along the rotational axis direction of the heating roller  11 ), and multiple peeling claws  15  are arranged on the support frame  25  along the rotational axis direction of the heating roller  11  with fixed intervals therebetween. The claw tips  15   a  of the peeling claws  15  contact the surface of the heating roller  11 , and are supported in a movable state so as to approach the heating roller  11  or retract by moving apart from the heating roller  11 . 
         [0041]      FIG. 3  is an exploded perspective view showing the support structure of the peeling claw  15 .  FIG. 4A  and  FIG. 4B  are perspective views showing the support structure of the peeling claw  15  as viewed from above and below respectively.  FIG. 5A ,  FIG. 5B , and  FIG. 5C  are a lateral view, a top view, and a front view showing the support structure of the peeling claw  15 . 
         [0042]    As shown in  FIGS. 3 to 5 , the peeling claw  15  is supported at an inner side of the peeling claw holder  31 , and the peeling claw holder  31  is supported at an inner side of a support casing  32  (referred to as a “support member” in the present invention). 
         [0043]    The peeling claw  15  is provided with the claw tip  15   a,  and a shaft hole  15   c  is formed in a substantially central location of the peeling claw  15 . Furthermore, the peeling claw holder  31  is provided with a main panel  31   a,  side panels  31   b  that are bent on either side of the main panel  31   a,  and a hook  31   c  that protrudes from an end portion of the main panel  31   a,  and a pair of shaft holes  31   d  and  31   e  are formed in each of the side panels  31   b.  The peeling claw  15  is arranged on the inner side of the peeling claw holder  31  so as to be covered by the main panel  31   a  and the pair of side panels  31   b  of the peeling claw holder  31 . 
         [0044]    The support casing  32  is provided with a main panel  32   a,  side panels  32   b  that are bent on either side of the main panel  32   a,  and securing panels  32   c  that are bent from one lateral side of the side panels  32   b  (from a side on one side that is perpendicular to a bent location (bending line) of the side panel  32   b ) to a direction opposite from the other side panel  32   b.  A guide groove  33  is formed in each of the side panels  32   b.  Two perforations  32   d  are formed in each of the securing panels  32   c,  and engaging portions  32   e  are provided that bend from end portions of the securing panels  32   c  (from end portions on the side of one side perpendicular to the bent location (bending line) of the securing panels  32   c ). The peeling claw holder  31  is arranged on the inner side of the support casing  32  so as to be covered by the main panel  32   a  and the pair of side panels  32   b  of the support casing  32 . 
         [0045]    As is evident from  FIG. 3 , the peeling claw holder  31  is arranged at the inner side of the side panels  32   b  of the support casing  32 , the side panels  31   b  of the peeling claw holder  31  are overlapped by the side panels  32   b  of the support casing  32 , and the pair of shaft holes  31   d  and  31   e  of the side panels  31   b  of the peeling claw holder  31  are overlapped by the guide groove  33  of the side panels  32   b  of the support casing  32 . 
         [0046]    Furthermore, the peeling claw  15  and a torsion spring  34  are arranged at the inner side of side panels  31   b  of the peeling claw holder  31 , the shaft hole  15   c  of the peeling claw  15  is overlapped by the shaft holes  31   d  of the side panels  31   b  of the peeling claw holder  31 , and coil portions  34   a  of the torsion spring  34  are overlapped by the shaft holes  31   e  of the side panels  31   b  of the peeling claw holder  31 . At this time, two end portions  34   b  of the torsion spring  34  are arranged at outer sides of the main panel  31   a  of the peeling claw holder  31 , and a central portion  34   c  of the torsion spring  34  hooks onto one end  15   d  of the peeling claw  15 . 
         [0047]    And a pin  35  inserts through the guide groove  33  of the side panels  32   b  of the support casing  32 , the shaft holes  31   d  of the side panels  31   b  of the peeling claw holder  31 , and the shaft hole  15   c  of the peeling claw  15  such that a retaining ring  36  couples to a groove  35   e  at one end of the pin  35 . Furthermore, another pin  37  inserts through the guide groove  33  of the side panels  32   b  of the support casing  32 , the shaft holes  31   e  of the side panels  31   b  of the peeling claw holder  31 , and the coil portions  34   a  of the torsion spring  34  such that a retaining ring  38  couples to a groove  37   e  at one end of the pin  37 . In this way, the peeling claw holder  31  is supported at the inner side of the side panels  32   b  of the support casing  32 , and the peeling claw  15  and the torsion spring  34  are supported at the inner side of the side panels  31   b  of the peeling claw holder  31 . Due to these pins  35  and  37 , the peeling claw holder  31  is supported in the guide groove  33  of the support casing  32  so as to be capable of moving in an approaching direction of approaching the heating roller  11 , and a retracting direction of retracting by moving apart from the heating roller  11 . In relation to movement of the peeling claw holder  31  in the retracting direction of these two directions, the peeling claw holder  31  moves in the retracting direction while the pins  35  and  37  are guided in the guide groove  33 . For this reason, the peeling claw  15 , which is supported by the peeling claw holder  31 , moves in the retracting direction accompanying the peeling claw holder  31 . The retracting direction in which the peeling claw holder  31  can move that is referred to in the present embodiment is set to directions between a vertical direction and a horizontal direction, that is, two or more directions, and the peeling claw holder  31  retracts (moves) in these directions accompanying the movement direction of the pin  35  within this range. It should be noted that the claw tip  15   a  of the peeling claw  15  displaces in relation to movement of the pin  35 . Specifically, the peeling claw  15  displaces accompanying movement of the pin  35 , and on that basis the peeling claw  15  rotates based on the movement direction of the pin  35 , which alters according to the edges of the guide groove  33 , and the claw tip  15   a  rotationally displaces according to this rotation. Detailed movements of the peeling claw  15  are described later. 
         [0048]    Further still, hooks  39   a  at both ends of a coil spring  39  hook onto the engaging portions  32   e  of the securing panels  32   c  of the support casing  32 , and a central portion of the coil spring  39  hooks onto the hook  31   c  of the main panel  31   a  of the peeling claw holder  31 . 
         [0049]    In this manner, the peeling claw  15 , the peeling claw holder  31 , and the support casing  32  are assembled, the securing panels  32   c  of the support casing  32  are mounted onto the support frame  25  shown in  FIG. 2 , the securing panels  32   c  are screwed onto the support frame  25  via the four perforations  32   d  using four screws (not shown in drawings), the support casing  32  is secured on the support frame  25 , and the peeling claw  15  is provided on the support frame  25 . 
         [0050]    Next, description is given regarding movement of the peeling claw  15  that is supported by the peeling claw holder  31 . As is evident from  FIG. 6A , the coil portions  34   a  of the torsion spring  34  are supported through the pin  37 , the two end portions  34   b  of the torsion spring  34  press against the main panel  31   a  of the peeling claw holder  31 , and the central portion  34   c  of the torsion spring  34  hooks onto the one end  15   d  of the peeling claw  15 . In this state, the end portions  34   b  and the central portion  34   c  try to move apart from each other due to the biasing force of the torsion spring  34 , and therefore the one end  15   d  of the peeling claw  15  is pushed down by the central portion  34   c  of the torsion spring  34 , the peeling claw  15  rotates in the counterclockwise direction around the pin  35 , and the claw tip  15   a  of the peeling claw  15  contacts the surface of the heating roller  11 . That is, the claw tip  15   a  of the peeling claw  15  is lightly pressed against the surface of the heating roller  11  due to the biasing force of the torsion spring  34 . 
         [0051]    The peeling claw  15  is only biased in the counterclockwise direction by the torsion spring  34 , and therefore by causing the peeling claw  15  to rotate in the clockwise direction against the biasing force of the torsion spring  34  as shown in  FIG. 6B , it is possible for the peeling claw  15  to move apart from the surface of the heating roller  11 . 
         [0052]    Next, description is given regarding movement of the peeling claw holder  31  that is supported by the support casing  32  and the peeling claw  15 . As is evident also from  FIG. 7A , the guide grooves  33  of the side panels  32   b  of the support casing  32  are V-shaped, and are provided with a first guide groove portion  33   a  and a second guide groove portion  33   b.  The first guide groove portion  33   a  guides the pin  35  and the second guide groove portion  33   b  guides the pin  37 , and the connection location of the first guide groove portion  33   a  and the second guide groove portion  33   b  is the folding point in the V shape. Since the pins  35  and  37  are inserted through the pairs of shaft holes  31   d  and  31   e  of the side panels  31   b  of the peeling claw holder  31 , when the pins  35  and  37  move and are guided by the first and second guide grooves  33   a  and  33   b,  the peeling claw holder  31  and the peeling claw  15  are also guided and move accompanying this. Accordingly, the peeling claw holder  31  and the peeling claw  15  are guided and move in accordance with the first and second guide grooves  33   a  and  33   b.    
         [0053]    The width of the second guide groove portion  33   b  is slightly wider than the diameter of the pin  37 , and due to the relationship between the width of the second guide groove portion  33   b  and the diameter of the pin  37 , the pin  37  is guided smoothly by the second guide groove portion  33   b.  Furthermore, the second guide groove portion  33   b  is substantially a straight line in shape (formed as an aperture having a substantially straight line shape), and the pin  37  is guided in a straight line by the second guide groove portion  33   b.    
         [0054]    Except for its front end, the width of the first guide groove portion  33   a  is amply wider on its front end side than the diameter of the pin  35 , and gradually becomes narrower from the front end side toward its anchoring end side, which is on the second guide groove portion  33   b  side, and is equivalent to the width of the second guide groove portion  33   b  at its anchoring end, which is the connection location with the second guide groove portion  33   b.  The pin  35  has the same diameter as the pin  37 , and the width of the first guide groove portion  33   a  is slight wider than the pin  37  at the connection location with the second guide groove portion  33   b.    
         [0055]    Furthermore, a circular arc edge  33   c  that delineates a same arc as the outer circumference of the pin  35  is formed at the front end of the first guide groove portion  33   a,  and a vertical direction guide edge  33   d  and a horizontal direction guide edge  33   e  are formed continuing on from the circular arc edge  33   c.  The first guide groove portion  33   a  is constituted by the circular arc edge  33   c,  the vertical direction guide edge  33   d,  and the horizontal direction guide edge  33   e,  and the vertical direction guide edge  33   d  and the horizontal direction guide edge  33   e  are opposing portions that are not parallel. It should be noted that the vertical direction guide edge  33   d  includes a first slanted guide edge  33   f  that extends slanting diagonally upward with respect to the vertical direction. Furthermore, the horizontal direction guide edge  33   e  includes a second slanted guide edge  33   g  that extends slanting diagonally upward with respect to the horizontal direction. The ends of the first slanted guide edge  33   f  and the second slanted guide edge  33   g  become the anchoring end of the first guide groove portion  33   a.    
         [0056]    Here, the hooks  39   a  at both ends of a coil spring  39  hook onto the engaging portions  32   e  of the support casing  32 , and the central portion of the coil spring  39  hooks onto the hook  31   c  of the peeling claw holder  31 , and therefore as shown in  FIG. 7A , the peeling claw holder  31  is biased and moves in the direction of arrow C by the coil spring  39 , and the pins  35  and  37  also move in the direction of arrow C such that the pin  35  is positioned by contacting the circular arc edge  33   c  of the first guide groove portion  33   a,  and accompanying this, the pin  37  is positioned on the left side of the second guide groove portion  33   b  (the anchoring end of the second guide groove portion  33   b ). At this time, the claw tip  15   a  of the peeling claw  15  is lightly pressed against the surface of the heating roller  11  due to the biasing force of the torsion spring  34  in the same manner as shown in FIG. GA. 
         [0057]    In a case where a vertical direction force of arrow D is applied to the peeling claw holder  31  or the peeling claw  15  in the state shown in  FIG. 7A , first the pin  35  moves apart from the circular arc edge  33   c  of the first guide groove portion  33   a  as shown in  FIG. 7B  and moves in a vertical direction along the vertical direction guide edge  33   d,  after which the pin  35  moves diagonally upward along the first slanted guide edge  33   f  continuing from the vertical portion of the vertical direction guide edge  33   d  as shown in  FIG. 7C , and accompanying this the pin  37  moves to the right side of the second guide groove portion  33   b  (away from the anchoring end side of the second guide groove portion  33   b ). At this time, the claw tip  15   a  of the peeling claw  15  moves diagonally upward as shown in  FIG. 7B  and  FIG. 7C  to delineate a trajectory J moving apart from the surface of the heating roller  11 . 
         [0058]    Furthermore, in a case where a horizontal direction force of arrow E is applied to the peeling claw holder  31  or the peeling claw  15  in the state shown in  FIG. 8A  equivalent to  FIG. 7A , that is, in a state in which the pin  35  is positioned by contacting the circular arc edge  33   c  of the first guide groove portion  33   a  and the claw tip  15   a  of the peeling claw  15  is lightly pressed against the surface of the heating roller  11 , the pin  35  moves apart from the circular arc edge  33   c  of the first guide groove portion  33   a  as shown in  FIG. 8B  and moves in a horizontal direction along the horizontal direction guide edge  33   e,  after which the pin  35  moves diagonally upward along the second slanted guide edge  33   g  continuing from the horizontal portion of the horizontal direction guide edge  33   e  as shown in  FIG. 8C , and accompanying this the pin  37  moves to the right side of the second guide groove portion  33   b  (away from the anchoring end side of the second guide groove portion  33   b ). At this time, the claw tip  15   a  of the peeling claw  15  moves diagonally upward as shown in  FIG. 8B  and  FIG. 8C  (more steeply diagonally upward than shown in  FIG. 7B  and  FIG. 7C ) to delineate a trajectory K moving apart from the surface of the heating roller  11 . 
         [0059]    Accordingly, when a force of a vertical direction of arrow D or a horizontal direction of arrow E is applied to the peeling claw holder  31  or the peeling claw  15 , the peeling claw holder  31  moves in that vertical direction or horizontal direction, and the claw tip  15   a  of the peeling claw  15  retracts from the surface of the heating roller  11  delineating the trajectory J or K. 
         [0060]    Further still, when a force of a range contained between the vertical direction of arrow D or the horizontal direction of arrow E is applied to the peeling claw holder  31  or the peeling claw  15 , the peeling claw holder  31  moves in a range between the vertical direction or horizontal direction, and the claw tip  15   a  of the peeling claw  15  moves apart from the surface of the heating roller  11  delineating a trajectory between the trajectory J of  FIG. 7B  and  FIG. 7C  and the trajectory K of  FIG. 8B  and  FIG. 8C . 
         [0061]    That is, when a force of a range from the vertical direction of arrow D to the horizontal direction of arrow E is applied to the peeling claw holder  31  or the peeling claw  15 , the peeling claw holder  31  readily moves in the range from the vertical direction to the horizontal direction, and the claw tip  15   a  of the peeling claw  15  retracts from the surface of the heating roller  11 . 
         [0062]    Here, in  FIG. 1 , when a paper blockage (jam) occurs in the vicinity of the peeling claw  15  and the paper stacks up, a force of the range from the vertical direction of arrow D to the horizontal direction of arrow E is applied to the peeling claw holder  31  or the peeling claw  15  by the paper. For this reason, when the peeling claw holder  31  or the peeling claw  15  is pushed by the paper, the peeling claw holder  31  readily moves in the range from the vertical direction to the horizontal direction, and the claw tip  15   a  of the peeling claw  15  reliably retracts from the surface of the heating roller  11  such that a situation does not occur in which the claw tip  15   a  strongly presses against the surface of the heating roller  11 . 
         [0063]    In contrast to this, in a case where the movement trajectory of the holder when the separation claw holder moves along the groove is on a single line and the movement direction of the holder is prescribed to a single direction as is the case conventionally, the holder or the separation claw does not move at all according to the direction of pressing by the paper, and the tip of the separation claw strongly presses against the surface of the fixing roller, thereby sometimes causing damage to the surface of the fixing roller or damage to the peeling claw. 
         [0064]    The foregoing described preferable embodiments of the present invention with reference to the accompanying drawings, but the present invention is not limited to these examples. It is evident that a person skilled in the art would be capable of conceiving various modifications and alterations within the scope described by the claims, and naturally all of these are to be interpreted as belonging to the technical scope of the present invention. 
         [0065]    For example, to adjust the movement direction of the claw tip  15   a  of the peeling claw  15 , the shape of the guide grooves  33  of the side panels  32   b  of the support casing  32  may be altered. 
         [0066]    Furthermore, in the foregoing embodiment, the retracting directions of the peeling claw holder  31  were set to directions between the vertical direction and the horizontal direction (including the vertical direction and the horizontal direction), but these are directions corresponding to an arrangement relationship among the peeling claw  15 , the peeling claw holder  31 , and the heating roller  11 , and the shape of the guide groove  33  in the present embodiment, and there is no limitation to this as long as there are two or more retracting directions of the peeling claw holder  31  so that the peeling claw  15  retracts by moving apart from the fixing roller  11 . That is, directions other than the retracting directions shown in the present embodiment are possible as long as it is a direction in which the peeling claw  15  moves apart from the heating roller  11  such that the claw tip  15   a  of the peeling claw  15  is caused to move apart away from the heating roller  11 . As a specific configuration, the transport direction of the paper (arrow D in the present embodiment) and a direction orthogonal to the transport direction (arrow E in the present embodiment) are possible as retracting directions of the peeling claw holder  31 . For example, in a case where there is a form in which the peeling claw  15  and the peeling claw holder  31  and the heating roller  11  are arranged in a row along a 45 degree direction with respect to the horizontal direction and the guide grooves  33  according to the present embodiment are used, the two directions may be directions tilted 45 degrees from the vertical direction and the horizontal direction respectively, and the retracting directions may be directions between these directions. 
         [0067]    Furthermore, in the above-described present embodiment, the present invention was applied only to the peeling claw  15  against the heating roller  11 , but there is no limitation to this and the present invention may also be applied to the peeling claw  16  against the pressure roller  12 , and in this case the peeling claw  16 , the peeling claw holder  31 , and the support casing  32  according to the present embodiment are assembled to achieve an equivalent effect as the above-described present embodiment. It should be noted that a configuration in which the peeling claw  16 , the peeling claw holder  31 , and the support casing  32  are assembled is an equivalent configuration as the configuration in which the peeling claw  15 , the peeling claw holder  31 , and the support casing  32  of the present embodiment are assembled, and therefore illustration thereof is omitted.