JP5267061B2 - Recording medium conveying apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording medium conveying device capable of suppressing generation of impact sound when the recording medium finishes passing between a pair of rotating bodies. <P>SOLUTION: This conveying device 60 includes a first roll 88 and second roll 92, arm members 84 and 85 for supporting the second roll 92, and a retract cam 98 formed with an urethane resin layer 98A. When recording paper P enters between the first roll 88 and the second roll 92, burrs of end parts in the recording paper P are smoothed by pressing force. At this time, the first roll 88 and the second roll 92 are separated by a distance corresponding to thickness of the recording paper P. When a rear end of the recording paper P passes between the first roll 88 and the second roll 92, the arm member 84 returns to its original position, and a roll follower 97 and the retract cam 98 are brought into contact with each other. In this case, the retract cam 98 is provided with the urethane resin layer 98A, and thereby impact force due to the contact is reduced, and generated noise is suppressed. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a recording medium conveyance device and an image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus that transports a recording sheet with a plurality of roller pairs and forms an image on the recording sheet with ink or toner is used. Among such image forming apparatuses, there is an image forming apparatus provided with leveling means for leveling burrs in the cut portion of the recording paper in the middle of the conveyance path (for example, see Patent Documents 1 and 2).

In each of the image forming apparatuses disclosed in Patent Documents 1 and 2, a pair of rolls having irregularities on the surface is arranged in the middle of the conveyance path of the recording paper between the sheet feeding device and the alignment roll (registration roll). The pair of rolls level the burrs at the cut portion of the recording paper with the recording paper sandwiched therebetween. In Patent Document 1, a heater is provided in a metal core, and a roller pair whose surface is coated with a Teflon (registered trademark) coat is used.
Japanese Patent Laid-Open No. 10-218459 JP 2005-179041 A

  An object of the present invention is to provide a recording medium conveying apparatus and an image forming apparatus that can suppress the generation of an impact sound when a recording medium has passed between a pair of rotating bodies.

According to a first aspect of the present invention, there is provided a recording medium transporting apparatus, comprising: a first rotating body that is rotatably provided in a recording medium transport path; and a rotation medium that is rotatably provided to face the first rotating body. A second rotating body that presses toward the first rotating body and conveys to the downstream side of the conveying path, and supports the second rotating body rotatably, and a support provided at a position different from the second rotating body. A support member provided so as to be swingable about an axis; and provided at a position facing the support member; swinging the support member to contact or approach the first rotating body and the second rotating body; Alternatively, the contacting / separating means to be separated and the contact portion of the contacting / separating means are provided at a portion that contacts the support member, and the support member swings before or before the second rotating body contacts the first rotating body. Sometimes the position of the support member is different from the second rotating body Contact with, having, an impact force reducing member for reducing an impact force due to contact of the first rotor and the second rotor.

Here, “adjacent” means to make the gap between the first rotating body and the second rotating body smaller than a predetermined thickness of the recording medium, and “separation” means the first It means that the gap between the rotating body and the second rotating body is made larger than the maximum thickness of the recording medium that can be transported by the recording medium transporting device.

An image forming apparatus according to claim 2 of the present invention includes a recording medium conveying apparatus according to claim 1, wherein the recording medium transport device is provided downstream in the transport direction of the recording medium than the mounting portion to be mounted, the recording And an image forming unit that forms an image on the recording medium conveyed by the medium conveying device.

An image forming apparatus according to claim 3 of the present invention includes a recording medium conveying apparatus according to claim 1, wherein the recording medium transport device is provided downstream in the transport direction of the recording medium than the mounting portion to be mounted, the recording When an image forming unit that forms an image on the first surface and the second surface of the recording medium conveyed by the medium conveying device and the recording medium after the image is formed on the first surface pass through the recording medium conveying device. And control means for controlling the contacting / separating means so as to separate the first rotating body and the second rotating body.

In an image forming apparatus according to a fourth aspect of the present invention, a vibration reducing member for reducing vibration of the recording medium conveying device is provided between the attachment portion and the recording medium conveying device.

An image forming apparatus according to claim 5 of the present invention is provided with a plurality of the vibration reducing members, and the rigidity of the vibration reducing member to which the weight of the recording medium transport device is the largest is the vibration reducing member to which the weight is the largest. Is higher than the rigidity of the different vibration reducing members.

  According to the first aspect of the present invention, it is possible to suppress the generation of an impact sound when the recording medium finishes passing between the pair of rotating bodies, as compared with the case where no impact force reducing member is provided.

According to the first aspect of the present invention, the cleaning operation of the first rotating body and the second rotating body is facilitated as compared with the case where no contact / separation means is provided.

According to the second aspect of the present invention, compared to the case where the present configuration is not provided, the image forming unit provided on the downstream side of the recording medium conveyance direction with respect to the recording medium conveyance device is attached to a member that contacts the recording medium. Scratches can be reduced.

According to a third aspect of the present invention, the image on the first surface is compared with the case where the first rotating body and the second rotating body are not separated when the recording medium after the image is formed on the first surface passes. Disturbance can be suppressed.

The invention of claim 4 can suppress the generation of impact sound as compared with the case where the present configuration is not provided.

According to the fifth aspect of the present invention, the positional deviation of the recording medium conveyance device can be suppressed to a smaller extent than when the present configuration is not provided.

  A recording medium conveying apparatus and an image forming apparatus according to a first embodiment of the invention will be described with reference to the drawings.

  FIG. 1 shows a printer 10 as an image forming apparatus. The printer 10 includes a plurality of image forming units 12 (12Y, 12M, 12C, 12K) on which toner images of each color component are formed by an electrophotographic method, and each color component toner image formed by each image forming unit 12. Intermediate transfer belt 14 that is sequentially transferred (primary transfer) and held, and secondary transfer that collectively transfers (secondary transfer) the toner image transferred and superimposed on intermediate transfer belt 14 onto recording paper P as a recording medium. The apparatus 16 and a fixing device 18 for fixing the toner image secondarily transferred onto the recording paper P are provided. Moreover, it has the control apparatus 20 which controls operation | movement of each apparatus (each part).

  Each image forming unit 12 (12Y, 12M, 12C, 12K) includes a charging roll 24 for charging the photosensitive member 22 around the cylindrical photosensitive member 22 rotating in the direction of arrow A, and exposure light on the photosensitive member 22. Are formed on the photosensitive member 22, a laser exposure unit 26 that forms an electrostatic latent image by the toner, a developing device 28 that stores toner of each color component and visualizes the electrostatic latent image on the photosensitive member 22 with toner. A primary transfer roll 30 for transferring the toner images of the respective color components to the intermediate transfer belt 14 and a cleaning unit 32 for removing residual toner on the photoreceptor 22 are sequentially provided. These image forming units 12 are arranged substantially linearly in the order of yellow (Y color), magenta (M color), cyan (C color), and black (K color) from the upstream side in the moving direction of the intermediate transfer belt 14. Has been.

  Note that when distinguishing each color of yellow, magenta, cyan, and black, Y, M, C, and K are added after the code. However, if there is no need to distinguish each color, Y, M, C, and K are omitted. Further, since the members other than the toner in the plurality of image forming units 12 (12Y, 12M, 12C, and 12K) have the same configuration, the members of the image forming unit 12Y are assigned a reference numeral to form an image. The reference numerals of the units 12M, 12C, and 12K are omitted.

  Each color toner is negatively charged, and a colorant or wax is internally added to a binder resin such as polyester or styrene acrylic by suspension polymerization, emulsion aggregation and coalescence, dissolution suspension, or the like. Fine particles formed. The toners Y, M, C, and K are not particularly limited by the manufacturing method, and various toners can be used.

The intermediate transfer belt 14 is formed so that a volume resistivity is 10 ⁶ to 10 ¹⁵ Ω · cm by adding an appropriate amount of carbon black or the like to a resin such as polyimide, polycarbonate, polyester, polypropylene, polyethylene terephthalate, or various rubbers. The thickness is set to 0.1 mm, for example. Further, the intermediate transfer belt 14 is driven by a motor (not shown) having excellent constant speed, and a driving roll 34 that drives the intermediate transfer belt 14 to circulate, and the intermediate transfer belt 14 along the arrangement direction of the photosensitive members 22. A support roll 36 that supports the straight portion is provided. Further, the intermediate transfer belt 14 applies a constant tension to the intermediate transfer belt 14 and prevents the meandering of the intermediate transfer belt 14, and a cleaning unit 40 that scrapes residual toner on the intermediate transfer belt 14. A cleaning backup roll 42 is provided so as to face each other. In this way, the intermediate transfer belt 14 is stretched by various rolls, and is circulated (rotated) in the direction of arrow B at a predetermined speed.

  A voltage having a polarity opposite to the charging polarity of the toner is applied to each primary transfer roll 30 facing each photoconductor 22. As a result, the toner images on the respective photosensitive members 22 are sequentially electrostatically attracted to the intermediate transfer belt 14 to form toner images superimposed on the intermediate transfer belt 14.

  On the upstream side of the image forming unit 12Y, a reference sensor (home position sensor) 44 that generates a reference signal serving as a reference for taking the image forming timing in each image forming unit 12 (12Y, 12M, 12C, 12K) is disposed. An image density sensor 46 for adjusting image quality is disposed downstream of the image forming unit 12K. The reference sensor 44 recognizes a predetermined mark provided on the intermediate transfer belt 14 and generates a reference signal. Each image forming unit 12 starts image formation according to an instruction from the control device 20 based on the recognition of the reference signal.

  On the other hand, paper trays 50 </ b> A and 50 </ b> B for storing two types of recording paper P are disposed at the lower part of the printer 10. Paper feed rolls 52A and 52B are provided at one end of the paper trays 50A and 50B to take out and transport the accumulated recording paper P at a predetermined timing, and are fed out by the paper feed rolls 52A and 52B. The recorded recording paper P is sent to the secondary transfer device 16 through a paper transport path 56 formed by a plurality of pairs of transport rolls 54.

  A registration roll 58 composed of a pair of rolls is provided on the upstream side of the sheet transfer path 56 from the secondary transfer device 16. The registration roll 58 is rotatable by a motor (not shown), and the operation of rotation or rotation stop is controlled by the control device 20 based on the detection signal of the reference sensor 44. Further, on the upstream side of the registration roll 58 in the paper conveyance path 56, a conveyance device 60 that is attached to an attachment portion 62 provided in the printer 10 and conveys the recording paper P and reduces cutting burrs of the recording paper P. Is provided.

  A conveyance belt 64 that conveys the recording paper P onto which the toner image has been secondarily transferred to the fixing device 18 is provided on the downstream side in the conveyance direction of the recording paper P of the secondary transfer device 16. A pair of discharge rollers 66 for discharging the recording paper P to the outside of the printer 10 is provided on the downstream side of the fixing device 18 in the conveyance direction of the recording paper P. A collection tray 68 is provided outside the printer 10, and the recording paper P discharged by the discharge roll 66 is collected on the collection tray 68.

  On the other hand, from the downstream side of the fixing device 18 to the upstream side of the transport device 60, a paper reversing path 70 is provided in which the recording paper P is transported and the front and back are reversed by the movement of a switching lever (not shown). The sheet reversing path 70 includes a plurality of guide plates (not shown) arranged in a curved shape or a straight shape, a conveyance roll 72 arranged between the guide plates and rotated to convey the recording paper P, and the recording paper P. A switching unit 74 that temporarily accommodates and switches back and switches the conveyance direction.

  Here, the recording sheet P on which the fixing of the image on the front surface (one side) has been completed by the fixing device 18 is conveyed to the switching unit 74 side, and the conveyance direction is reversed by the switching unit 74. Subsequently, the image is conveyed through the sheet reversing path 70, and image formation on the back surface is performed again by the secondary transfer device 16 via the conveying device 60 and the resist roll 58. Then, the image is fixed by the fixing device 18 and discharged by the discharge roll 66.

  Next, the transport device 60 will be described.

  As shown in FIGS. 2A and 2B, the transport device 60 has a main body 78 having a U-shaped cross section. Side plates 79 and 80 are provided at both ends of the main body portion 78 in the direction intersecting the conveyance direction of the recording paper P (from the front side to the back side in FIG. 2), and between the side plates 79 and 80. A cylindrical support shaft 82 is installed and fixed. Arm members 84 and 85 made of sheet metal are attached to the outer sides of the side plates 79 and 80 at both ends of the support shaft 82 via bearings 83. Thus, the arm members 84 and 85 can swing with respect to the main body 78 with the support shaft 82 as a fulcrum.

  Further, in the transport device 60, through holes (not shown) are formed in the side plates 79 and 80, and bearings 86 are fitted and fixed in the through holes. Here, the both ends of the shaft 87 are inserted into the two bearings 86, so that the first roll 88 is rotatably provided. The first roll 88 is connected to a motor (not shown) at one end, and is rotated in the direction of the arrow by the rotation of the motor.

  On the other hand, a through hole (not shown) is formed in the arm members 84 and 85, and a bearing 89 is fitted and fixed in the through hole. Here, by inserting both ends of the shaft 90 into the two bearings 89, the second roll 92 is rotatably provided. The second roll 92 is driven to rotate as the first roll 88 is rotated by a motor.

  The first roll 88 and the second roll 92 are made of any metal material such as SUS, S45C, SKTM11, etc., and any one of titanium nitride coating, DLC (Diamond_Like_Carbon) coating, hard chrome plating, etc. on the outer peripheral surface. Hard surface treatment is applied. The surface hardness is 500 Hv or more in terms of Vickers hardness. Moreover, the roll diameter of the 1st roll 88 and the 2nd roll 92 is 35 mm or more, and the roll length is 350-360 mm.

  Pins 93 project from the ends of the arm members 84, 85 on the opposite side to the support shaft 82 toward both outer sides, and the lower sides of the pins 93 on the side plates 79, 80 are directed toward both outer sides. A pin 94 is projected. Here, both ends of the coil spring 95 are hooked on the pins 93 and 94, respectively, and the restoring force of the coil spring 95 acts on the arm members 84 and 85. Thereby, the edge part on the opposite side to the spindle 82 of the arm members 84 and 85 is urged | biased below, and the outer peripheral surface of the 1st roll 88 and the outer peripheral surface of the 2nd roll 92 are contacting. The first roll 88 and the second roll 92 are configured to attract each other with a load of 50 kgf. In the present embodiment, no elastic layer is provided on the outer peripheral surfaces of the first roll 88 and the second roll 92, but unless an elastic layer is provided in at least a region of the outer peripheral surface through which the recording paper P passes. As compared with the case where the elastic layer is provided, a larger pressing force is applied to the end portion of the recording paper P that passes therethrough.

  Note that the first roll 88 and the second roll 92 may be maintained in an adjacent state with a predetermined gap by the action of the retract cam 98. This gap is set to an amount smaller than the thickness of the recording paper that needs to reduce burr, and is actually a value of 50 to 100 μm.

  Further, the lower end of the arm members 84, 85 on the pin 93 side is formed with a protruding portion 84A that protrudes downward in a substantially triangular shape. The protruding portion 84A has pins 96 facing outward. Projected. A bearing-shaped roll follower 97 is externally attached to the pin 96, and an E-ring (not shown) is attached to the end of the pin 96, so that the roll follower 97 can rotate without coming out of the pin 96. ing.

  A shaft 99 is installed between the side plate 79 and the side plate 80 via bearings (not shown), and retract cams 98 are fixed to both ends of the shaft 99, respectively. Thereby, the retract cam 98 can rotate in the arrow direction.

  The retract cam 98 has an outer peripheral shape combining a large diameter arc and a small diameter arc. When the first roll 88 and the second roll 92 are in contact with each other, the outer peripheral surface of the roll follower 97 and the small diameter side of the retract cam 98 are arranged. It arrange | positions so that an outer peripheral surface may contact. Further, the retract cam 98 has a urethane resin layer 98A as an impact force reducing member formed on the outer peripheral surface.

  On the upstream side of the first roll 88 and the second roll 92 in the conveyance direction of the recording paper P, upper and lower paper guides 102 that constitute the path of the recording paper P are provided. Similarly, on the downstream side of the first roll 88 and the second roll 92, there are provided upper and lower paper guides 104 that constitute a path of the recording paper P that has passed through the contact area between the first roll 88 and the second roll 92. Yes.

  A plurality of damper members 110 (110A, 110B, 110C) made of rubber such as urethane rubber are provided on the bottom lower surface side of the main body 78.

  The damper members 110 </ b> A to 110 </ b> C are provided at a plurality of locations (for example, three locations at both ends and the central portion) at intervals along the axial direction of the shaft 87. The damper member 110A and the damper member 110C have substantially the same hardness, but the damper member 110B is harder than the damper members 110A and 110C. In the present embodiment, the damper members 110A to 110C are fastened and fixed to the upper surface of the mounting portion 62 and the bottom portion of the main body portion 78 by screws or the like (not shown). Also good.

  Next, the operation of the first embodiment of the present invention will be described.

  As shown in FIG. 1, first, image data output from an image reading device (not shown), a personal computer (PC), or the like is input to the printer 10. In the printer 10, after predetermined image processing is performed by an image processing apparatus (not shown), the operation of each unit is performed by the control apparatus 20, and image formation is performed by the image forming unit 12.

  Here, the image processing apparatus performs predetermined image processing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame deletion, color editing, and moving editing on the input reflectance data. Is done. The image data subjected to the image processing is converted into color material gradation data of four colors of yellow (Y), magenta (M), cyan (C), and black (K), and is output to the laser exposure unit 26. .

  Subsequently, in the laser exposure device 26, the exposure light emitted from the semiconductor laser according to the input color material gradation data is irradiated onto the surface of each photoconductor 22 charged by the charging roll 24. Each photoconductor 22 is scanned and exposed by a laser exposure device 26 to form an electrostatic latent image. The formed electrostatic latent images are respectively yellow (Y), magenta (M), cyan (C), and black (K) toners by the developing device 28 in the image forming units 12Y, 12M, 12C, and 12K. Developed as an image.

  The toner image formed on the photoconductor 22 is sequentially superimposed on the surface of the intermediate transfer belt 14 at the primary transfer portion where each photoconductor 22 and the intermediate transfer belt 14 come into contact, and primary transfer is performed. The primarily transferred toner image is conveyed to the secondary transfer device 16 as the intermediate transfer belt 14 rotates.

  On the other hand, in the paper transport path 56, the paper feed rolls 52A and 52B and the transport roll 54 rotate in accordance with the image formation timing, and a recording paper P of a predetermined size is sent out from the paper tray 50A or the paper tray 50B. The sent recording paper P is transported by the transport roll 54 and enters the transport device 60.

  Subsequently, as shown in FIG. 3A, the recording paper P that has entered the transport device 60 is sandwiched and pressed between the first roll 88 and the second roll 92 and is transported downstream. As a result, even if there are burrs or the like due to cutting at the end of the recording paper P, it is reduced by the pressing force. Here, while the recording paper P exists between the first roll 88 and the second roll 92, the arm member 84 is moved upward according to the thickness of the recording paper P. For this reason, a gap is formed between the roll follower 97 and the retract cam 98.

  Subsequently, as shown in FIG. 3B, when the trailing edge of the recording paper P passes between the first roll 88 and the second roll 92, the roll follower 97 is lowered and collides with the retract cam 98. Due to this collision, an impact force acts at the contact portion between the roll follower 97 and the retract cam 98.

  At this time, since the urethane resin layer 98A is provided on the outer peripheral surface of the retract cam 98, the impact force is absorbed by the elastic force. Thereby, compared with the case where the urethane resin layer 98A is not provided in the retract cam 98, an impact sound is reduced. Further, in this embodiment, even if the main body 78 of the transport device 60 vibrates due to the collision of each member, the damper members 110A to 110C are interposed between the transport device 60 and the mounting portion 62, so that the noise source is The enlargement within the printer 10 is suppressed.

  In addition, since the damper member 110B that is harder than the damper members 110A and 110C is disposed below the contact area between the first roll 88 and the second roll 92, the rigidity in this portion is increased, and the first roll 88 and the second roll 92 are less likely to be inclined with respect to the conveyance direction of the recording paper P. As a result, jamming of the recording paper P in the contact area between the first roll 88 and the second roll 92, traveling in an oblique direction, and the like are suppressed. Further, when a damper member is disposed on the lower side in the gravity direction of a drive motor (not shown) for driving the first roll 88, the rigidity of the damper member may be higher than that of other damper members.

  Subsequently, as shown in FIG. 1, the recording paper P whose burr has been reduced by the conveying device 60 reaches the registration roll 58 and is temporarily stopped to move the intermediate transfer belt 14 on which the toner image is held (reference). It is conveyed to the secondary transfer device 16 in accordance with (detected by the sensor 44). As a result, the conveyance position of the recording paper P and the transfer position of the toner image are aligned.

  Subsequently, the recording paper P on which the toner image is electrostatically transferred from the intermediate transfer belt 14 in the secondary transfer device 16 is peeled off from the intermediate transfer belt 14 and conveyed to the conveyance belt 64. The conveyance belt 64 conveys the recording paper P to the fixing device 18 in accordance with the optimum conveyance speed in the fixing device 18. The unfixed toner image on the recording paper P is fixed on the recording paper P by being subjected to a fixing process with heat and pressure by the fixing device 18. The recording paper P on which the fixed image is formed is discharged to a collection tray 68 outside the printer 10 by a discharge roll 66.

  When double-sided (front and back) image formation is performed, the recording paper P that has been fixed on the front surface enters the switching unit 74, the transport direction is switched, and the paper is transported along the paper reversing path 70. Enter 60. Here, after the burr is reduced again, it is conveyed to the resist roll 58. When the recording paper P re-enters the transport device 60, the retract cam 98 is controlled by the control device 20 to avoid excessive pressing of the recording paper P, and the first roll 88 and the second roll 92 are separated from each other. It does not matter. Thereafter, similarly, secondary transfer and fixing of the toner image to the back surface are performed, and image formation on both sides is completed.

  After the transfer of the toner image onto the recording paper P is completed, the residual toner remaining on the intermediate transfer belt 14 is conveyed to the cleaning unit 40 as the intermediate transfer belt 14 rotates, and is removed from the intermediate transfer belt 14. The

  Here, noise was measured according to the measurement method of ISO7779 or JISX7779, and from this result, the A characteristic acoustic power level (unit decibel: dB) defined in ISO9296 or JISX7779 was calculated, and the noise improvement effect was evaluated.

  In the noise measurement, the apparatus A is provided with neither the urethane resin layer 98A nor the damper members 110A to 110C, the apparatus B is provided with the urethane resin layer 98A, and the apparatus B is provided with the damper members 110A to 110C. The apparatus A to C was performed with the apparatus provided with any of the damper members 110A to 110C as the apparatus C.

  The noise measuring device used was Multi_Channel_Data_Station_DS9110 made by ONO_SOKKI, and MI3110 made by ONO_SOKKI was used as a microphone for collecting sound. As measurement conditions, the recording paper P was A4 paper having a thickness of 230 μm manufactured by Fuji Xerox Co., Ltd., with the conveyance direction A4 side and the conveyance speed of 500 mm / s.

  As a result of the noise measurement, the device A is 80 dB, the device B is 77 dB, and the device C is 74 dB, and the urethane resin layer 98A is provided compared to the urethane resin layer 98A and the damper members 110A to 110C. The noise reduction of 3 dB, the urethane resin layer 98 </ b> A, and the damper members 110 </ b> A to 110 </ b> C both provided 6 dB noise reduction.

  The transport device 60 can be disposed not only at a position near the registration roll 58 on the upstream side of the registration roll 58 but also at a position near the paper tray 50A as shown in FIG. 4, for example. In this case, the recording paper P that has once passed through the conveying device 60 does not pass through the conveying device 60 again because the recording paper P that has been fixed on the surface does not pass through the conveying device 60 even when performing double-sided image formation. There is no need to separate the second roll 92 from the first roll 88 during formation. However, from the viewpoint of facilitating cleaning of the first roll 88 and the second roll 92, it is preferable to rotate the retract cam 98 and arrange the second roll 92 apart from each other except during the printing operation.

  Next, a second embodiment of the recording medium conveyance device and the image forming apparatus of the present invention will be described. Note that components that are basically the same as those in the first embodiment described above are given the same reference numerals as those in the first embodiment, and descriptions thereof are omitted.

  FIG. 5A shows a conveying device 120 provided in a printer 100 as an image forming apparatus. The printer 100 has a configuration in which the conveyance device 120 is provided in place of the conveyance device 60 in the printer 10 (see FIG. 1) of the first embodiment, and there is no sheet reversing path 70 (see FIG. 1), and recording is performed. Image formation is performed only on one side of the paper P.

  As shown in FIGS. 5A and 5B, the transport device 120 has a housing 122 that is a device main body. Side plates 123 and 125 are provided at both ends of the casing 122 in a direction intersecting the conveyance direction of the recording paper P (from the front side to the rear side in FIG. 5), and between the side plates 123 and 125. The support shaft 82 is installed and fixed. Arm members 124 and 126 made of sheet metal are attached via bearings 83 to the outside of the side plates 123 and 125 at both ends of the support shaft 82. Thus, the arm members 124 and 126 can swing with respect to the housing 122 with the support shaft 82 as a fulcrum.

  Further, in the conveying device 120, through holes (not shown) are formed in the side plates 123 and 125, and bearings 86 are fitted and fixed in the through holes. Here, the both ends of the shaft 87 are inserted into the two bearings 86, so that the first roll 88 is rotatably provided. The first roll 88 is connected to a motor (not shown) at one end, and is rotated in the direction of the arrow by the rotation of the motor.

  On the other hand, through holes (not shown) are formed in the arm members 124 and 126, and bearings 89 are fitted and fixed in the through holes. Here, by inserting both ends of the shaft 90 into the two bearings 89, the second roll 92 is rotatably provided. The second roll 92 is driven to rotate as the first roll 88 is rotated by a motor.

  Pins 93 project from the ends of the arm members 124 and 126 opposite to the support shaft 82 toward both outer sides, and the lower sides of the pins 93 on the side plates 123 and 125 are directed toward both outer sides. A pin 94 is projected. Here, both ends of the coil spring 95 are hooked on the pins 93 and 94, respectively, and the restoring force of the coil spring 95 acts on the arm members 124 and 126. Thereby, the edge part on the opposite side to the spindle 82 of the arm members 124 and 126 is urged | biased below, and the outer peripheral surface of the 1st roll 88 and the outer peripheral surface of the 2nd roll 92 are contacting. The first roll 88 and the second roll 92 are configured to attract each other with a load of 50 kgf.

  Further, the lower end portions of the arm members 124 and 126 on the pin 93 side are substantially flat, and a plate-like urethane rubber 128 as an impact force reducing member is in contact with the lower end portions. The urethane rubber 128 is bonded and fixed to the upper surface of a plate-like protrusion 127 that protrudes outward from the surfaces of the side plates 123 and 125, respectively. At this time, the first roll 88 and the second roll 92 may be maintained in an adjacent state with a predetermined gap by the action of the urethane rubber 128. This gap is set to an amount smaller than the thickness of the recording medium where it is necessary to reduce burrs, and actually takes a value of 50 to 100 μm.

  Next, the operation of the second embodiment of the present invention will be described. Note that the image forming process of the printer 100 is almost the same as the image forming process of the printer 10, and thus the description thereof will be omitted, and the operation of the transport device 120 will be mainly described.

  Similar to the printer 10 shown in FIG. 1, in the printer 100, the paper feed rolls 52A and 52B and the transport roll 54 rotate in accordance with the timing of image formation, and the recording paper P of a predetermined size is fed from the paper tray 50A or the paper tray 50B. Is sent out. The sent recording paper P is transported by the transport roll 54 and enters the transport device 120.

  Subsequently, as shown in FIG. 6A, the recording paper P that has entered the transport device 120 is sandwiched and pressed between the first roll 88 and the second roll 92 and is transported toward the downstream side. Thereby, even if burrs or the like due to cutting exist at the end of the recording paper P, they are reduced by pressing. Here, while the recording paper P exists between the first roll 88 and the second roll 92, the arm member 124 is moved upward according to the thickness of the recording paper P. For this reason, a gap is formed between the lower end surface of the arm member 124 and the urethane rubber 128.

  Subsequently, as shown in FIG. 6B, when the trailing edge of the recording paper P passes between the first roll 88 and the second roll 92, recording is performed between the first roll 88 and the second roll 92. Since the sheet P no longer exists, the lower end surface of the arm member 124 descends and collides with the urethane rubber 128. Due to this collision, an impact force acts on the contact portion between the first roll 88 and the second roll 92, the lower end surface of the arm member 124, and the contact portion between the urethane rubber 128, respectively.

  At this time, since the urethane rubber 128 is provided on the lower end surface of the arm member 124, the impact force is absorbed by the elastic force. Thereby, compared with the case where the urethane rubber 128 is not provided, the impact sound is reduced.

  In the present embodiment, even if the casing 122 of the transport device 120 vibrates due to the collision of each member, the vibration is transported because the damper members 110A to 110C are interposed between the transport device 120 and the mounting portion 62. It propagates only in the apparatus 120 and the noise source is prevented from expanding in the printer 100.

  Subsequently, as shown in FIG. 1, the recording paper P on which the burr has been reduced by the conveying device 120 passes through the registration roll 58, the secondary transfer device 16, and the fixing device 18, so that the toner image is secondary transferred. And fixed. Then, the paper is discharged to a collection tray 68 outside the printer 100 by a discharge roll 66.

  In addition, this invention is not limited to said embodiment.

  The image forming apparatus is not limited to an electrophotographic system such as the printer 10 but may be an inkjet system or a printing plate printing system. Further, not only the first roll 88 and the second roll 92 but also a pair of rolls for transporting the recording paper P may be provided in the transport devices 60 and 120.

  The arrangement position of the roll follower 97, the retract cam 98, or the urethane rubber 128 may be between the first roll 88 and the second roll 92 and the support shaft 82. Further, instead of the roll follower 97 and the retract cam 98, a solenoid or a linear slider may be provided. In this case, a spring may be used as an impact force reducing member.

  The conveyance device 60 may be suspended from the attachment portion 62 in the direction of gravity. In this case, the impact force reducing member is disposed above the conveying device 60 in the gravity direction, but the weight of the conveying device 60 is the highest (for example, on the upper side in the weight direction of the first roll 88 and the second roll 92). The rigidity of the impact force reducing member may be higher than the rigidity of the other impact force reducing members.

  When a plurality of impact force reducing members are provided, more impact force reducing members may be provided in a portion where a greater weight is applied.

  On the outer peripheral surfaces of the first roll 88 and the second roll 92, an elastic layer such as a urethane resin layer or a urethane rubber layer may be provided as long as it is an axial end portion through which the recording medium does not pass. However, in this case, due to the thickness of the elastic layer, the first roll 88 and the second roll 92 have a gap in the region through which the recording paper P passes, and the variability of the recording paper P having a thickness equal to or smaller than the gap is present. Is difficult to reduce. Therefore, when it is desired to reduce the burr of the recording paper P having any thickness that passes through the conveying devices 60 and 120, no elastic layer is provided on the outer peripheral surfaces of the first roll 88 and the second roll 92, and the first roll 88. In addition, it is preferable to provide the impact force reducing member only at a position different from the second roll 92.

1 is an overall view of an image forming apparatus according to a first embodiment of the present invention. (A), (b) It is the side view and sectional drawing of the conveying apparatus which concern on 1st Embodiment of this invention. (A), (b) It is a side view which shows the operation state of the conveying apparatus which concerns on 1st Embodiment of this invention. It is a general view of an image forming apparatus as another example of the first embodiment of the present invention. (A), (b) It is the side view and sectional drawing of the conveying apparatus which concern on 2nd Embodiment of this invention. (A), (b) It is a side view which shows the operation state of the conveying apparatus which concerns on 2nd Embodiment of this invention.

Explanation of symbols

10 Printer (image forming device)
12 Image forming unit (image forming unit)
56 Paper transport path (transport path)
60 Conveying device (recording medium conveying device)
62 Mounting part (Mounting part)
82 Support shaft (support shaft)
84 Arm member (support member)
85 Arm member (support member)
88 First roll (first rotating body)
92 Second roll (second rotating body)
98 Retract cam (contact / separation means)
98A Urethane resin layer (impact force reducing member)
100 printer (image forming apparatus)
110 Damper member (vibration reducing member)
120 Conveying device (recording medium conveying device)
124 Arm member (support member)
126 Arm member (support member)
128 Urethane rubber (impact force reducing member)
P Recording paper (recording medium)

Claims (5)

A first rotating body provided rotatably in a recording medium conveyance path;
A second rotating body that is rotatably provided facing the first rotating body, presses the recording medium toward the first rotating body, and transports the recording medium to the downstream side of the transport path;
A support member that rotatably supports the second rotating body and that is swingable about a support shaft provided at a position different from the second rotating body;
Contact / separation means provided at a position facing the support member and swinging the support member to bring the first rotating body and the second rotating body into contact with each other or in proximity to or away from each other;
The contact member is provided at a part of the contact member that contacts the support member, and the support member swings and the second rotating body contacts the first rotating body before or when the second rotating body contacts the first rotating member. An impact force reducing member that is in contact with a position different from that of the second rotating body and reduces an impact force due to contact between the first rotating body and the second rotating body;
A recording medium conveying apparatus having A recording medium conveying apparatus according to claim 1;
An image forming unit provided on the downstream side in the conveyance direction of the recording medium with respect to the attachment unit to which the recording medium conveyance device is attached, and forms an image on the recording medium conveyed by the recording medium conveyance device;
An image forming apparatus . A recording medium conveying apparatus according to claim 1;
An image forming unit that is provided on the downstream side in the recording medium conveyance direction with respect to the attachment unit to which the recording medium conveyance device is attached, and forms images on the first surface and the second surface of the recording medium conveyed by the recording medium conveyance device When,
Control means for controlling the contacting / separating means to separate the first rotating body and the second rotating body when the recording medium after the image is formed on the first surface passes through the recording medium conveying device. When,
An image forming apparatus. The image forming apparatus according to claim 2, wherein a vibration reduction member that reduces vibration of the recording medium conveyance device is provided between the attachment portion and the recording medium conveyance device. A plurality of the vibration reducing members are provided, and the rigidity of the vibration reducing member that takes the most weight of the recording medium transport device is higher than the rigidity of the vibration reducing member that is different from the vibration reducing member that takes the most weight. 5. The image forming apparatus according to 4.

Images