JP2009265292A - Separation device and image forming device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separation device capable of securing stable separation performance by a separation member, by preventing a tip part of the separation member abutting on a rotor from floating up by a deflection when rotating the rotor, and capable of prolong lives of the separation member and the rotor by restraining a foreign matter from being bitten between the rotor and the separation member, to restrain abrasion on a surface of the rotor, and an image forming device using the same. <P>SOLUTION: This separation device 30 is provided with a paper sheet separation claw 31 for separating a paper sheet from a photoreceptor drum 3, and a paper sheet separation claw driving mechanism 40 for bringing the paper sheet separation claw 31 into contact and separation with/from the photoreceptor drum 3, the paper sheet separation claw 31 is provided with a separation part 31a abutting on the photoreceptor drum 3, the separation part 31a is journaled turnably around a rotation fulcrum as the center, the separation part 31a is provided to abut inclinedly toward a rotation-directional upstream of the photoreceptor drum 3, and the paper sheet separation claw driving mechanism 40 is provided with a cam body 41 for displacing a turning fulcrum of the paper sheet separation claw 31. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a peeling device and an image forming apparatus using the same, and more particularly, to a peeling device for peeling a sheet-like member attached to the outer peripheral portion of a rotating body with a peeling member, and an image forming apparatus using the peeling device.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a facsimile or printer using an electrophotographic method, a photosensitive drum that is rotationally driven is charged by a charger, and an electrostatic latent image is formed on the photosensitive drum by light irradiation according to image information. Then, a toner image is formed by attaching toner to the electrostatic latent image by a developing device, and the toner image is transferred to a recording medium such as a sheet material or paper to output an image.

  In such an image forming apparatus, after the toner image formed on the photosensitive drum is transferred to the recording medium, the peeling is performed to prevent the recording medium from being electrostatically stuck to the photosensitive drum. 2. Description of the Related Art There is known a device equipped with a peeling device that slides a member against a photosensitive drum to forcibly peel the recording medium from the photosensitive drum.

Hereinafter, an example of a conventional peeling apparatus will be described with reference to the drawings.
FIG. 8 is an explanatory view showing a schematic configuration of a conventional peeling apparatus, FIG. 9A is an explanatory view showing a contact state with a photosensitive drum when a paper peeling claw of the peeling apparatus is worn, and FIG. It is detail drawing of the H section of (a).

  As a conventional technique related to a peeling apparatus, for example, in an image forming apparatus, as shown in FIG. 8, in order to forcibly peel a sheet (recording medium) from a photosensitive drum 3, a tapered wedge-shaped sheet peeling claw (peeling member) ) 131 is brought into contact with the photosensitive drum 3 with a constant load, and a peeling device is provided to mechanically peel the paper adsorbed on the surface of the photosensitive drum 3.

  As shown in FIG. 8, the sheet peeling claw 131 is rotatably held by a support shaft 132 serving as a rotation fulcrum, and the tip 131 a of the paper peeling claw 131 is opposed to the photosensitive drum 3. In consideration of damage to the spring, it is biased in the direction of the arrow SP by a spring member (not shown) so as to come into contact with a weak load of about 1 g.

  Since the photosensitive drum 3 rotates with the paper peeling claw 131 in contact with the photosensitive drum 3, as the rotation time (number of sheets passing) of the photosensitive drum 3 increases, as shown in FIGS. The contact portion 131b of the tip 131a of the sheet peeling claw 131 is worn out. If the wear progresses quickly, the life of the sheet peeling claw 131 must be set short, and the maintenance cycle cannot be extended.

  Further, if a material having extremely high wear resistance is used for the paper peeling claw 131 in order to suppress the wear of the paper peeling claw 131, the photosensitive drum 3 is damaged and damaged. This causes a problem of shortening.

  Further, if the tip 131a of the sheet peeling claw 131 is worn, the tip 131a of the sheet peeling claw 131 is lifted from the photosensitive drum 3 by the rotation of the photosensitive drum 3 due to slight eccentricity of the photosensitive drum 3, There arises a problem that the paper peeling performance is lowered. That is, when the paper is not peeled from the photosensitive drum 3 by the paper peeling claw 131, a paper jam occurs in the apparatus.

Therefore, as a countermeasure against the above-described conventional problems, for example, in a peeling device mounted on an image forming apparatus, as a configuration of a claw-like peeling member that is brought into contact with the photosensitive drum, the shape of the surface facing the photosensitive drum is set to be photosensitive. There has been proposed a toner formed on the surface of the body drum so as to be able to pass the toner without blocking it (see Patent Document 1). With this configuration, the surface of the photosensitive drum is prevented from being damaged due to partial wear of the tip of the claw-like peeling member.
JP-A-11-219035

  However, in the above-described configuration of the related art, the position of the rotating shaft that rotatably supports the nail-shaped peeling member is fixed, and therefore, the nail-shaped peeling member and the photosensitive drum are worn by wear of the tip of the nail-shaped peeling member. As a result, the tip of the nail-like peeling member (the end of the contact surface) rises due to the influence of the shake of the photosensitive drum, causing a peeling failure. Further, as the contact area between the claw-like peeling member and the photosensitive drum increases, foreign matter between the claw-like peeling member and the photosensitive drum may be caught, and the biting of the foreign matter causes wear of the photosensitive drum. The problem arises.

  The present invention has been made in view of the above-described conventional problems, and prevents the tip of the peeling member that comes into contact with the rotating body from being lifted due to vibration during rotation of the rotating body, thereby stabilizing the peeling member. Peeling device capable of ensuring the peeling performance and suppressing the biting of foreign matter between the rotating body and the peeling member, and suppressing the wear of the surface of the rotating body, thereby extending the life of the peeling member and the rotating body, and this An object of the present invention is to provide an image forming apparatus using the above.

The configuration of a peeling apparatus according to the present invention and an image forming apparatus using the same for solving the above-described problems is as follows.
The present invention provides a peeling member that abuts on a sheet-like member conveyed along the outer peripheral surface of a rotating cylindrical rotating body and peels the sheet-like member from the rotating body, and the peeling member is used as the rotating body. In a peeling device that has a peeling member driving means for contacting and separating, and peels off a sheet-like member attached to the outer peripheral surface of the rotating body, as a configuration of the peeling member, a tapered wedge shape that contacts the outer peripheral surface of the rotating body And the peeling member is pivoted in a direction perpendicular to the axial direction of the rotating body around a rotation fulcrum passing through a line parallel to the axis of the rotating body. That is, in other words, pivotally supported along a plane perpendicular to the axis of the rotating body, and the tip portion is on the upstream side in the rotational direction of the rotating body with respect to the outer peripheral surface of the rotating body. Set to abut against each other That is, it is arranged so that the tip end abuts on the upstream side in the rotation direction of the rotating body with respect to the rotation fulcrum, and the rotation fulcrum displacement that displaces the rotation fulcrum of the peeling member as a configuration of the peeling member driving means. Means are provided.

In the present invention, it is preferable that the rotation fulcrum displacement means displaces the rotation fulcrum of the peeling member as the tip of the peeling member wears.
That is, the rotation fulcrum displacement means changes the contact position of the tip portion of the peeling member with the rotating body as it wears by sliding contact with the outer peripheral surface of the rotating body.

In the present invention, it is preferable that the rotation fulcrum displacing means displaces the rotation fulcrum of the peeling member so as to be separated from the rotating body in the radial direction of the rotating body.
That is, the rotation fulcrum displacement means changes the contact position of the distal end portion of the peeling member with the rotating body to the distal end side.

  In the present invention, it is preferable that the peeling member is inclined in a direction approaching a vertical state with respect to a tangent line between the tip portion and the rotating body as the rotation fulcrum of the peeling member is displaced. .

  The present invention also provides an image carrier on which a toner image is formed, a transfer unit that transfers a toner image formed on the image carrier while conveying a recording medium along the image carrier, and the transfer unit. In an image forming apparatus that includes a peeling device that peels off a recording medium attached to the image carrier during a transfer step by the transfer method, and that transfers a toner image formed on the surface of the image carrier onto the recording medium and outputs an image. The peeling device according to any one of claims 1 to 4 is used as the peeling device.

  According to the present invention, the peeling member that comes into contact with the sheet-like member conveyed along the outer peripheral surface of the rotating cylindrical rotating body and peels the sheet-like member from the rotating body, and the peeling member is rotated. A peeling device that includes a peeling member driving unit that contacts and separates from the body, and peels off the sheet-like member attached to the outer peripheral surface of the rotating body. As a configuration of the peeling member, a taper that contacts the outer peripheral surface of the rotating body is provided. A wedge-shaped tip is provided, and the peeling member can be rotated in a direction perpendicular to the axis of the rotating body around a rotation fulcrum where the tip passes through a line parallel to the axis of the rotating body. And the tip end portion is provided so as to incline and contact with the outer peripheral surface of the rotating body toward the upstream side in the rotational direction of the rotating body. Displace the pivot point of By providing the pivot fulcrum displacement means, the contact position between the tip of the peeling member and the rotating body can be moved and the good contact state between the tip and the rotating body can always be maintained. Can be ensured over a long period of time, and a longer life of the peeling member and the rotating body can be achieved.

  Further, according to the present invention, the rotation fulcrum displacement means displaces the rotation fulcrum of the peeling member as the tip of the peeling member wears, so that the tip of the peeling member becomes Even if the tip is in contact with the rotating body due to sliding contact with the rotating body, the contact position of the tip with the rotating body is moved so that the tip always rotates with the rotating body. Since the good contact state with the body can be maintained, the peeling performance by the peeling member can be ensured over a long period of time.

  Further, according to the present invention, the peeling fulcrum displacing means displaces the turning fulcrum of the peeling member so as to be separated from the rotating body in the radial direction of the rotating body. Since the contact position of the tip portion with the rotating body can be displaced toward the tip side, a good contact state between the tip portion and the rotating body can always be maintained.

  Further, according to the present invention, as the rotation fulcrum of the peeling member is displaced, the peeling member is inclined in a direction approaching a vertical state with respect to a tangent line between the tip portion and the rotating body. Thus, since the contact position of the distal end portion of the peeling member with the rotating body can be displaced toward the distal end side, a good contact state between the distal end portion and the rotating body can always be maintained.

  According to the present invention, an image carrier on which a toner image is formed, a transfer unit that transfers a toner image formed on the image carrier while conveying a recording medium along the image carrier, An image forming apparatus that includes a peeling device that peels off the recording medium attached to the image carrier during a transfer process by a transfer unit, and transfers the toner image formed on the surface of the image carrier onto the recording medium to output an image. In the apparatus, by using the peeling device according to any one of claims 1 to 4 as the peeling device, the contact position of the tip portion of the peeling member with the image carrier is moved, Since the good contact state between the tip portion and the image carrier can always be maintained, the peeling performance by the peeling member can be secured over a long period of time, and the life of the peeling member and the image carrier can be increased. Can do. As a result, it is possible to realize an image forming apparatus that can prevent troubles caused by sticking of a recording medium over a long period of time and enables stable image output.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
FIG. 1 is an explanatory view showing the overall configuration of an image forming apparatus provided with a peeling apparatus according to an embodiment of the present invention, and FIG. 2 is a partial detailed view showing the configuration of the apparatus main body of the image forming apparatus.

  In the present embodiment, as shown in FIG. 1, a photosensitive drum (image carrier) 3 on which a toner image is formed and a sheet-like recording paper (recording medium) are conveyed while being conveyed along the photosensitive drum 3. A transfer mechanism (transfer means) 10 for transferring a toner image formed on the photosensitive drum 3 and a peeling device 30 for peeling a recording sheet attached to the photosensitive drum 3 during a transfer process by the transfer mechanism 10 are provided. In the image forming apparatus 1A for transferring the toner image formed on the surface 3 onto a recording sheet and outputting the image, the peeling device 30 includes the configuration of the peeling device according to the present invention. is there.

  First, the overall configuration of the image forming apparatus 1A according to the present embodiment will be described with reference to the drawings.

  The image forming apparatus 1A outputs and forms image data transmitted from the outside as a monochrome image on a predetermined sheet-like recording sheet (hereinafter referred to as a sheet) serving as a recording medium by electrophotography.

  As shown in FIGS. 1 and 2, the image forming apparatus 1A mainly includes an exposure unit (exposure unit) 1, a developing unit (developing unit) 2, a photosensitive drum (image carrier) 3, and a charger (charging unit). 4, an apparatus main body 1A1 including a cleaner unit 5, a fixing unit 6, a paper transport path 7, a paper feed tray 8, a paper discharge tray 9, a transfer mechanism 10, and the like, and an automatic document processing apparatus 1A2.

  A document placing table 21 made of transparent glass on which a document is placed is provided on the upper surface of the apparatus main body 1A1. Above the document placing table 21, the automatic document processing device 1A2 is swingably opened upward. On the other hand, a scanner unit 22 serving as a document reading unit that reads image information of a document is disposed below the document placing table 21.

  Below the scanner unit 22, an exposure unit 1, a developing device 2, a photosensitive drum 3, a charger 4, a cleaner unit 5, a fixing unit 6, a paper transport path 7, a paper discharge tray 9, and a transfer mechanism 10 are arranged. Further, below that, a paper feed tray 8 storing paper is disposed.

  The exposure unit 1 performs exposure by irradiating the surface of the photosensitive drum 3 uniformly charged by the charger 4 with laser light according to image data (image information for printing) output from an image processing unit (not shown). Thus, it has a function of writing and forming an electrostatic latent image corresponding to image data on the surface of the photosensitive drum 3.

  The exposure unit 1 is disposed immediately below the scanner unit 22 and above the photosensitive drum 3, and employs laser scanning units (LSU) 13 a and 13 b including a laser irradiation unit 11 and a reflection mirror 12. In the present embodiment, in order to perform high-speed printing processing, a technique of using a plurality of laser beams to reduce the irradiation timing is adopted, and a two-beam technique is adopted.

  In this embodiment, the laser scanning units (LSU) 13a and 13b are used for the exposure unit 1, but a light emitting element arranged in an array, for example, an EL or LED writing head may be used. .

  As shown in FIG. 2, the photosensitive drum 3 has a cylindrical shape, is disposed below the exposure unit 1, and is rotated in a predetermined direction (the direction of arrow A in the figure) by a driving unit and a control unit (not shown). Is controlled. Along the outer peripheral surface of the photosensitive drum 3, a peeling device 30 including a paper peeling claw (peeling member) 31 toward the downstream side in the rotational direction of the photosensitive drum with respect to a position after completion of image transfer, a cleaner unit 5, The charger 4 as the electric field generator and the developing device 2 are arranged in this order.

  The developing device 2 visualizes the electrostatic latent image formed on the photosensitive drum 3 with black toner, and is downstream of the charger 4 in the rotating direction of the photosensitive drum (the direction of arrow A in the figure). It is arranged substantially horizontally (right side in the figure) on the side of the photosensitive drum 3. A registration roller 15 is disposed below the developing unit 2 on the upstream side in the recording medium conveyance direction.

  The registration roller 15 is driven (not shown) so that the leading edge of the paper supplied from the paper feed tray 8 and the toner image on the photosensitive drum 3 are aligned and conveyed between the photosensitive drum 3 and the transfer belt 103. The operation is controlled by the means and the control means.

The charger 4 is a charging means for uniformly charging the surface of the photosensitive drum 3 to a predetermined potential, and is disposed above the photosensitive drum 3 and in the vicinity of the outer peripheral surface thereof.
In this embodiment, the charger type charger 4 is used. However, a contact type roller type or a brush type may be used.

  The cleaner unit 5 removes and collects toner remaining on the surface of the photosensitive drum 3 after development and image transfer. The cleaner unit 5 is located at a position substantially opposite to the developing device 2 with the photosensitive drum 3 interposed therebetween. The drum 3 is disposed substantially horizontally (left side in the drawing) on the side.

As described above, the electrostatic image visualized on the photosensitive drum 3 is applied on the sheet by applying the electric field having the opposite polarity to the electric charge of the electrostatic image from the transfer mechanism 10 onto the sheet to be conveyed. Is transcribed.
For example, when the electrostatic image has a charge of (−) polarity, the applied polarity of the transfer mechanism 10 is (+) polarity.

As shown in FIG. 2, the transfer mechanism 10 is bridged by a driving roller 101, a driven roller 102, and other rollers, and has a predetermined resistance value (1 × 10 ⁹ to 1 × 10 ¹³ Ω · cm in this embodiment). The transfer belt unit is disposed below the photosensitive drum 3 so that the surface of the transfer belt 103 contacts a part of the outer peripheral surface of the photosensitive drum 3. Has been. The transfer belt 103 conveys the paper while pressing it against the photosensitive drum 3.

  An elastic conductive roller 105 capable of applying a transfer electric field with a conductivity different from that of the driving roller 101 and the driven roller 102 is disposed at the contact portion 104 between the photosensitive drum 3 and the transfer belt 103.

  The elastic conductive roller 105 is made of a soft material such as elastic rubber or foamable resin. Since the elastic conductive roller 105 has elasticity, the photosensitive drum 3 and the transfer belt 103 are not in line contact but are in surface contact having a predetermined width (referred to as a transfer nip), so that the sheet is conveyed. The transfer efficiency can be improved.

  Further, on the downstream side of the transfer area of the transfer belt 103 in the paper conveyance direction, a neutralization roller 106 is provided to neutralize the electric field applied to the conveyed paper in the transfer area and smoothly carry it to the next process. 103 is arranged on the back side.

  In addition, the transfer mechanism 10 is provided with a cleaning unit 107 that removes dirt from the residual toner on the transfer belt 103 and a plurality of charge removal mechanisms 108 that perform charge removal on the transfer belt 103. As a technique for performing static elimination used in the static elimination mechanism 108, there is a technique of grounding through an apparatus, or a technique of positively applying a polarity opposite to the polarity of the transfer electric field.

  The electrostatic image (unfixed toner) transferred onto the paper by the transfer mechanism 10 is conveyed to the fixing unit 6 and is pressurized and heated, whereby the unfixed toner is melted and fixed on the paper.

  As shown in FIG. 2, the fixing unit 6 includes a heating roller 6a and a pressure roller 6b. The heating roller 6a is rotated while the sheet is sandwiched between the heating roller 6a and the pressure roller 6b, and the heating roller 6a is rotated. The toner image transferred onto the paper is melted and fixed by passing between 6a and the pressure roller 6b.

  On the downstream side of the fixing unit 6 in the paper conveyance direction, a conveyance roller 16 for conveying the paper is provided.

  The heating roller 6a is provided with a sheet peeling claw 611, a roller surface temperature detecting member (thermistor) 612, and a roller surface cleaning member 613 on the outer peripheral portion, and the heating roller surface is set to a predetermined temperature (fixing set temperature) on the inner peripheral portion. : Approximately 160 to 200 ° C.).

  The pressure roller 6b is provided with a pressure member 621 that allows the pressure roller 6b to come into pressure contact with the heating roller 6a at a predetermined pressure amount at both ends of the roller. Further, the pressure roller 6b is heated on the outer periphery of the pressure roller 6b. Similarly to the outer periphery of the roller 6a, a sheet peeling claw 622 and a roller surface cleaning member 623 are arranged.

  As shown in FIG. 2, in the fixing unit 6, unfixed toner on the conveyed paper is heated to the heating roller 6a in a pressure contact portion (so-called fixing nip portion) 600 between the heating roller 6a and the pressure roller 6b. The unfixed toner is fixed on the paper by a throwing action on the paper by the pressure contact force between the heating roller 6a and the pressure roller 6b.

  The paper feed tray 8 is for accumulating a plurality of sheets (paper sheets) on which image information is output (printed). The exposure unit 1, the developing device 2, the photosensitive drum 3, the charger 4, and the cleaner The image forming unit 14 includes a unit 5, a fixing unit 6, and the like. A semi-moon-shaped paper pickup roller (not shown) is disposed on the upper side of the paper discharge side of the paper feed tray 8.

  The paper pick-up roller picks up the sheets stacked and accommodated in the paper feed tray 8 one by one from the uppermost layer, toward the downstream side (for convenience, the paper flow-out side (cassette side) is upstream and the paper discharge side is It is conveyed downstream.) It is conveyed to the registration roller (also referred to as “idle roller”) 15 side on the sheet conveyance path 7.

  Note that in the image forming apparatus 1A according to the present embodiment, in order to perform high-speed printing processing, a plurality of standard size sheets can be stored in each tray below the image forming unit 14 in a plurality of 500 to 1500 sheets. On the other hand, a large-capacity paper feed cassette 81 capable of storing a large amount of a plurality of paper types is disposed on the side surface of the apparatus, and is mainly disposed above the large-capacity paper feed cassette 81. A manual feed tray 82 corresponding to standard size printing or the like is provided.

  The paper discharge tray 9 is disposed on the side of the apparatus opposite to the manual feed tray 82. Further, instead of the paper discharge tray 9, a post-processing device (device for performing stapling, punching, etc.) of paper discharge, a multi-stage paper discharge tray, and the like can be arranged as options.

  The paper conveyance path 7 is configured between the photosensitive drum 3 and the paper feed tray 8 described above, and conveys the paper supplied from the paper feed tray 8 to the transfer mechanism 10 one by one. The sheet on which the toner image is transferred from the body drum 3 is conveyed to the fixing unit 6, and after the unfixed toner image is fixed on the sheet in the fixing unit 6, the sheet conveyance path formed according to the designated processing mode The sheet is configured to be conveyed by the branching claw.

  Next, a sheet conveyance process corresponding to the processing mode of the image forming apparatus 1A will be described with reference to the drawings.

As shown in FIG. 1, the paper P that matches the print request is selected from a plurality of paper feed trays 8 and is transported to the registration rollers 15 by the transport rollers in the paper transport path 7.
As shown in FIG. 2, the sheet P that has stopped once reaching the registration roller 15 is transferred by the rotation of the registration roller 15 again at the timing when the leading edge of the sheet P and the image information on the photosensitive drum 3 are matched. After being transferred to the mechanism 10 and an unfixed toner image (image information) is transferred from the photosensitive drum 3 onto the paper P, the toner image is fixed onto the paper P by the fixing unit 6 and discharged to the paper discharge tray 9. The

  In the conveyance path in the sheet conveyance path 7, the sheet discharge tray from the fixing unit 6 onward is processed by the processing mode (copier mode, printer mode, FAX mode) of the image forming apparatus 1 </ b> A and the printing processing method (single-sided printing, duplex printing). The transport method up to 9 is different.

  Usually, in the copier mode, since the user performs an operation in the vicinity of the image forming apparatus 1A, a method called “face-up discharge” in which the printing surface is discharged with its upper side being used is often used.

  On the other hand, in each mode such as printer, FAX, etc., a “face-down discharge” method that aligns the page order of the discharged paper P because the user is not in the vicinity of the image forming apparatus 1A is often used.

  Accordingly, in the image forming apparatus 1A, the sheet P meeting the above purpose is discharged through the plurality of transport paths and the plurality of branch claws until the sheet P that has passed through the fixing unit 6 is discharged to the sheet discharge tray 9. Is supposed to do.

Next, the characteristic peeling apparatus 30 according to the present embodiment will be described in detail with reference to the drawings.
FIG. 3 is an explanatory diagram showing the configuration of the peeling device mounted on the image forming apparatus according to the present embodiment, and FIG. 4 is an explanatory diagram showing the configuration of the drive mechanism of the peeling device, as viewed from the direction of arrow A in FIG. 5A and 5B are explanatory views showing the configuration of the peeling member constituting the peeling device, where FIG. 5A is a front view of the peeling member, FIG. 5B is a view taken along the arrow A in FIG. It is a B arrow view of).

  As shown in FIGS. 3 and 4, the peeling device 30 according to the present embodiment abuts on a sheet (sheet-like member) conveyed along the outer peripheral surface of the photosensitive drum (image carrier, rotating body) 3. A paper peeling claw (peeling member) 31 that peels the paper from the photosensitive drum 3 and a paper peeling claw driving mechanism (peeling member driving means) 40 that contacts and separates the paper peeling claw 31 from the photosensitive drum 3, The paper affixed to the outer peripheral surface of the photosensitive drum 3 is configured to peel off.

  As shown in FIGS. 3 and 5A, the sheet peeling claw 31 is formed with a peeling portion (tip portion) 31a that contacts the outer peripheral surface of the photosensitive drum 3 on one end side, and is attached on the other end side. A hole 31c is formed, and the peeling portion 31a side is rotatably provided with the attachment hole 31c as a rotation fulcrum.

  Specifically, as shown in FIG. 5A, the paper peeling claw 31 has a peeling portion 31a on one end side formed in a wedge shape that tapers toward the tip. As shown in FIGS. 5B and 5C, the upper edge 31a1 and the lower edge 31a2 constituting the wedge shape of the peeling portion 31a are formed at acute angles.

  Further, as shown in FIG. 3, the sheet peeling claw 31 has a leading end of the peeling portion 31a by a spring member (not shown) (for example, a member that generates an elastic force (spring force) such as a coil spring, a leaf spring, or a rubber member). It is urged in the direction of the arrow SP and is pressed against the photosensitive drum 3 side.

  The sheet peeling claw drive mechanism 40 has a cam body 41 as a rotation fulcrum displacement means for displacing the rotation fulcrum of the sheet peeling claw 31, a drive motor 42 for driving the cam body 41, and a driving force from the drive motor 42. And a drive shaft 43 to be transmitted.

  The cam body 41 is provided between the drive shaft 43 and the sheet peeling claw 31 and constitutes a link mechanism. One end side 41 a is fixed integrally with the drive shaft 43, and The other end 41b is rotated with the rotation. A support shaft 32 that pivotally supports the sheet peeling claw 31 is integrally attached to the other end 41b.

  The axis 32 of the support shaft 32 is provided in parallel to the axis L1 of the photosensitive drum 3. A mounting hole 31c of the paper peeling claw 31 is rotatably engaged with the support shaft 32, and the peeling portion 31a side of the paper peeling claw 31 is perpendicular to the axial direction of the photosensitive drum 3 with the support shaft 32 as a rotation fulcrum. It is provided so as to be rotatable in the direction.

  Further, in the state where the paper peeling claw 31 is attached to the support shaft 32, the peeling portion 31 a of the paper peeling claw 31 is upstream of the rotation direction (arrow D direction) of the photosensitive drum 3 with respect to the outer peripheral surface of the photosensitive drum 3. It is arranged at a position where it inclines and abuts toward the side.

  Further, the cam body 41 moves from the photosensitive drum 3 in the radial direction of the photosensitive drum 3 with the rotation fulcrum of the sheet peeling claw 31, that is, the position of the supporting shaft 32 in accordance with the rotation of the drive shaft 43 provided integrally. It is made to displace so that it may space apart. That is, in this embodiment, as shown in FIG. 3, the cam body 41 rotates in the direction of arrow E with the drive shaft 43 as a rotation fulcrum so that the position of the support shaft 32 is separated from the photosensitive drum 3. It has become.

  Then, the sheet peeling claw 31 pivotally supported by the cam body 41 has a tangent that passes through the contact point between the tip of the peeling portion 31 a and the photosensitive drum 3 as the position of the spindle 32 moves away from the photosensitive drum 3. On the other hand, it is inclined in a direction approaching a vertical state.

  As shown in FIG. 4, the drive shaft 43 is provided in parallel to the axis L1 of the photosensitive drum 3, a cam body 41 is attached to a part of the outer periphery thereof, and at one end along the axial direction, A transmission gear 45 is provided through which rotational force is transmitted via a drive gear 44 attached to a spindle 42a of the drive motor 42.

A stepping motor is used as the drive motor 42.
The drive motor 42 is driven and controlled by a control unit (not shown) so as to rotate a predetermined amount when the tip of the peeling portion 31a of the paper peeling claw 31 is worn by a predetermined amount and to rotate the cam body 41 by a predetermined amount. .

  The amount of wear at the tip of the peeling portion 31a can be calculated empirically from the contact time between the photosensitive drum 3 and the peeling portion 31a (that is, the rotation time of the photosensitive drum 3). It is also possible to calculate in terms of the number of sheets passing through.

  Thus, in the peeling device 30 of this embodiment, the cam body 41 is rotated little by little as the tip of the peeling portion 31a of the paper peeling claw 31 wears, and the rotation fulcrum (support of the paper peeling claw 31 is supported. The shaft 32) is displaced.

Next, the operation of the peeling device 30 characteristic of the present embodiment will be described with reference to the drawings.
FIG. 6A is an explanatory view showing a contact state with the photosensitive drum when the paper peeling claw of the peeling apparatus according to the present embodiment is worn, and FIG. 6B is a detailed view of a portion F in FIG. FIG. 7A is an explanatory view showing a state in which the rotation fulcrum of the paper peeling claw is displaced after the paper peeling claw is worn, and FIG. It is detail drawing of the G section of Fig.7 (a) which shows a contact state.

  In the peeling device 30 in the image forming apparatus 1A according to the present embodiment, in order to forcibly peel the paper from the photosensitive drum 3, the paper peeling claw 31 has a peeling portion 31a of the paper peeling claw 31 as shown in FIG. It is urged in the direction of arrow SP by a spring member (not shown) so as to contact the photosensitive drum 3.

  When the accumulated time during which the photosensitive drum 3 rotates while the paper peeling claw 31 is pressed against the photosensitive drum 3 becomes longer, the peeling portion 31a of the paper peeling claw 31 that contacts the photosensitive drum 3 is changed to FIG. As shown in (b) and (b), the abutting portion 31b at the tip is worn and comes into contact with the photosensitive drum 3 on a flat surface.

  When the wear amount of the peeling portion 31a of the sheet peeling claw 31 reaches a predetermined amount, for example, when the maintenance cycle of the image forming apparatus 1A is set to 500K, the sheet passing number storage device (not described) ( When the number of sheets passed by the sheet passing counter) reaches 250K, the drive motor 42 is rotated by a predetermined angle by a stepping motor control device (not shown). Note that the value of K in the number of sheets to be passed is 1K being 1000 sheets.

  As the drive motor 42 rotates, the rotational drive is transmitted to the transmission gear 45 of the drive shaft 43 via the drive gear 44 of the drive motor 42. As a result, the cam body 41 rotates by a predetermined amount around the drive shaft 43, and the position of the support shaft 32 serving as the rotation fulcrum of the sheet peeling claw 31 is removed from the photosensitive drum 3 as shown in FIG. Move to a separated position.

  By rotating the cam body 41, the position of the rotation fulcrum of the sheet peeling claw 31 is changed from the position of the two-dot chain line in FIG. As shown in FIG. 7B, the photosensitive drum 3 comes into contact with the photosensitive drum 3 in a standing state, and as shown in FIG. 7B, the photosensitive drum 3 is exposed in a state where the contact portion 31b of the peeling portion 31a that is in contact with the plane is inclined. It comes into contact with the body drum 3. That is, the peeling portion 31a comes into contact with the photosensitive drum 3 at the tip again.

  As a result, the peeling portion 31a of the paper peeling claw 31 that has been worn by passing 250K sheets does not come into contact with the photosensitive drum 3 "surface contact", and "tip lift" does not occur. The tip of the peeled portion 31a newly becomes point contact (or edge contact), and it can be as if the paper peel claw 31 has been replaced.

  Therefore, according to the present embodiment, the life of the sheet peeling claw 31 can be extended without increasing damage to the photosensitive drum 3, the maintenance cycle can be expanded, and the downtime can be reduced. Become.

  With the above configuration, according to the present embodiment, as the configuration of the peeling device 30, the cam body 41 that displaces the rotation fulcrum of the paper peeling claw 31 is provided, and the photosensitive drum of the paper peeling claw 31 is provided by the cam body 41. Since the position of the rotation fulcrum of the sheet peeling claw 31 is moved in conjunction with the progress of wear of the peeling part 31 a due to contact with the sheet 3, the peeling part 31 a of the sheet peeling claw 31 always makes point contact with the photosensitive drum 3. Or it can be in the contact state by edge contact. This prevents the leading end of the sheet peeling claw 31 coming into contact with the photosensitive drum 3 from being lifted by a shake during rotation of the photosensitive drum 3, thereby ensuring stable peeling performance by the sheet peeling claw 31. At the same time, it is possible to suppress biting of foreign matter between the photosensitive drum 3 and the sheet peeling claw 31 and to suppress wear of the surface of the photosensitive drum 3, so that the length of the photosensitive drum 3 and the sheet peeling claw 31 can be reduced. Life expectancy can be realized. Therefore, by employing the peeling device according to the present invention in the image forming apparatus, it is possible to realize an image forming apparatus that enables stable image output over a long period of time.

  Further, according to the present embodiment, by moving the position of the rotation fulcrum of the paper peeling claw 31, the contact position of the peeling portion 31 a of the paper peeling claw 31 with the photosensitive drum 3 is changed and the point contact state or again Since the edge contact state can be obtained, even if the peeling portion 31a is worn, it can be continuously used without replacing the paper peeling claw 31. As a result, the life of the sheet peeling claw 31 and the maintenance can be simplified.

  In the present embodiment, a drive motor 42 using a pulse motor is used as the drive means in the configuration of the paper peeling claw drive mechanism 40. However, the present invention does not limit the drive means. As a modification, the cam body 41 may be rotated using a solenoid, and other driving means can be selected.

  Further, in the present embodiment, the cam body 41 constituting the link mechanism is adopted as the rotation fulcrum displacement means. However, the present invention is not limited to this as long as the rotation fulcrum of the peeling member can be displaced. It is not limited to.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. Embodiments obtained by appropriately combining the disclosed technical means are also included in the technical scope of the present invention.

  For example, in the above-described embodiment, the present invention is applied to a monochrome image forming apparatus. However, the present invention is applied to a color image forming apparatus (multifunction machine, printer, etc.) using a photosensitive drum. Is also possible.

1 is an explanatory diagram illustrating an overall configuration of an image forming apparatus including a peeling device according to an embodiment of the present invention. FIG. 2 is a partial detail view showing a configuration of an apparatus main body of the image forming apparatus. It is explanatory drawing which shows the structure of the peeling apparatus mounted in the said image forming apparatus. It is explanatory drawing which shows the structure of the drive mechanism of the said peeling apparatus, Comprising: It is A arrow view of FIG. (A) is a front view of the said peeling member, (b) is A arrow view of (a), (c) is B arrow view of (a). (A) is explanatory drawing which shows the contact state with the photoreceptor drum when the paper peeling nail | claw of the said peeling apparatus is worn, (b) is detail drawing of the F section of Fig.6 (a). (A) is explanatory drawing which shows the state which displaced the rotation fulcrum of the said paper peeling nail after the said paper peeling nail | wear was worn, (b) is detail drawing of the G section of (a). It is explanatory drawing which shows schematic structure of the conventional peeling apparatus. (A) is explanatory drawing which shows the contact state with the photoreceptor drum when the paper peeling nail | claw of the said peeling apparatus is worn, (b) is detail drawing of the H section of Fig.9 (a).

Explanation of symbols

1A Image forming apparatus 3 Photosensitive drum (image carrier)
10 Transfer mechanism (transfer means)
30 Peeling device 31 Paper peeling claw (peeling member)
31a Peeling part (tip part)
31b Abutting part 31c Mounting hole (rotating fulcrum)
32 Support shaft (rotating fulcrum)
40 Paper peeling claw driving mechanism (peeling member driving means)
41 Cam body (turning fulcrum displacement means)
42 Drive motor (peeling member drive means)
43 Drive shaft (peeling member drive means)

Claims (5)

A peeling member that comes into contact with a sheet-like member conveyed along an outer peripheral surface of a rotating cylindrical rotating body and peels the sheet-like member from the rotating body, and a peeling that makes the rotating member contact and separate from the rotating body In a peeling device comprising a member driving means, and peeling the sheet-like member attached to the outer peripheral surface of the rotating body,
The peeling member includes a tapered wedge-shaped tip that abuts on the outer peripheral surface of the rotating body, and the axis of the rotating body is centered on a rotation fulcrum that passes through a line parallel to the axis of the rotating body. And is pivotally supported so as to be rotatable in a direction perpendicular to the direction, and is provided so that the tip portion is inclined and abutted toward the upstream side in the rotational direction of the rotating body with respect to the outer peripheral surface of the rotating body,
The peeling device according to claim 1, wherein the peeling member driving means includes a rotation fulcrum displacement means for displacing a rotation fulcrum of the peeling member.   The peeling device according to claim 1, wherein the rotation fulcrum displacement means displaces the rotation fulcrum of the peeling member as the tip of the peeling member wears.   The peeling device according to claim 1 or 2, wherein the turning fulcrum displacement means displaces the turning fulcrum of the peeling member so as to be separated from the rotating body in the radial direction of the rotating body.   The said peeling member inclines in the direction which approaches a perpendicular state with respect to the tangent of the said front-end | tip part and a rotary body, as the rotation fulcrum of the said peeling member displaces. The peeling apparatus as described in any one of these. An image carrier on which a toner image is formed; transfer means for transferring a toner image formed on the image carrier while conveying a recording medium along the image carrier; and In an image forming apparatus comprising a peeling device for peeling a recording medium attached to a carrier, and transferring a toner image formed on the surface of the image carrier onto the recording medium to output an image.
An image forming apparatus using the peeling device according to claim 1 as the peeling device.

Images