JP2005274971A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for positioning and fixing with respect to the apparatus body, without employing disadvantage constitution to space saving and low cost by worsening the operability of the attachment and detachment of a unit concerning a shaft-like member, such as the shaft of a rotating body provided on the unit. <P>SOLUTION: The apparatus body is provided with a recess fixed to be positioned by fitting the shaft-like member of the unit; and an opening part of the recess is provided with a closing member, slidable in a direction which is substantially orthogonal to the attaching and detaching direction of the unit and for closing the opening part so as to prevent separation of the shaft-like member of the unit. The closing member slides, by an operation accompanying mounting operation of the unit, closes the opening part of the recess, is engaged with a part of the apparatus body, and prevents the shaft-like member of the unit from being moved in the separating direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine to which an electrophotographic system is applied, and in particular, a shaft shape such as a shaft of a rotating body of a unit configured to be detachable from the apparatus body. The present invention relates to a positioning and fixing means for positioning and fixing a member to the apparatus main body.

Japanese Patent Laid-Open No. 6-194892 JP 2001-324845 A

  Conventionally, as an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine to which this kind of electrophotographic method is applied, an image forming unit including a photosensitive drum is integrally formed in order to improve maintainability. The image forming unit is configured to be detachable from the main body of the image forming apparatus.

  In such an image forming apparatus, in order to reliably rotate and rotate the rotating body such as the photosensitive drum of the image forming unit mounted on the apparatus main body, the image forming unit is mounted on the apparatus main body, It is necessary to configure so that a drive gear that rotationally drives a rotating body such as a drum meshes with a gear of a drive system on the apparatus main body side. In the image forming apparatus, when the driving gear for rotating the rotating body such as the photosensitive drum is transmitted from the driving system gear on the apparatus main body side, the driving on the photosensitive drum side is performed. It is necessary to reliably prevent the image forming unit from being unintentionally displaced by the rotation moment acting on the gear.

  Therefore, as a technique for reliably rotating and rotating such a rotating body such as a photosensitive drum or preventing an unintentional displacement of the image forming unit, for example, Japanese Patent Laid-Open Nos. 6-194899 and 2001-324845 are known. There are some which are disclosed in the Gazette.

  The process cartridge disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 6-194899 is a process cartridge that can be mounted on the main body of an image forming apparatus, and includes a frame, an image carrier, process means acting on the image carrier, and image formation. And positioning means for positioning the drive transmission means provided on the image forming apparatus main body side when mounted on the apparatus main body.

  More specifically, the process cartridge disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 6-194899 has a structure in which the rotation axis of the image carrier is prevented from being displaced by the driving force of the drive gear. A U-groove is provided as positioning means having a predetermined angle with respect to the escape direction.

  Further, the process cartridge disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2001-324845 includes a motor, an apparatus main body side gear that is rotationally driven by the motor, a main body positioning member, and a protrusion that extends in the rotation center axis direction of the gear. And a connecting hole provided on the rotation center axis of the projecting portion. The process cartridge is attachable to and detachable from the main body of the electrophotographic image forming apparatus, and acts on the electrophotographic photosensitive drum and the electrophotographic photosensitive drum. A process protrusion, a connection protrusion in contact with the connection hole, the connection protrusion provided at a longitudinal end of the electrophotographic photosensitive drum, and a cartridge mounting portion provided in the apparatus main body. And a contact portion that is externally aligned with the projecting portion when the connection hole and the connection protrusion are connected. Those were.

  However, the conventional technique has the following problems. That is, in the case of the process cartridge disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 6-194899, the attaching / detaching direction of the process cartridge is such that the gear of the image carrier and the gear as the drive transmission means provided on the image forming apparatus main body side. Since the direction is set in a direction orthogonal to the inter-axis direction, the image carrier gear is provided on the image forming apparatus main body side when the process cartridge is attached to or detached from the image forming apparatus main body. There is a problem that it is difficult to attach and detach the process cartridge due to interference with the gear as the drive transmission means.

  Further, in the case of the process cartridge disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 6-194899, for the same reason, the direction of attaching / detaching the process cartridge and the arrangement of gears as drive transmission means provided on the image forming apparatus main body side For example, the process cartridge cannot be completely detached in the vertical direction and needs to be moved in an oblique direction, resulting in deterioration of detachability and an adverse effect on space saving. Have.

  On the other hand, in the case of the process cartridge disclosed in the above Japanese Patent Laid-Open No. 2001-324845, the shaft position of the rotating shaft or the like of the photosensitive drum is configured to be positioned by a coupling composed of a connection hole and a connection protrusion. However, in this case, the coupling of the device main body side gear inevitably needs to move along the axial direction, so a space corresponding to the amount of movement is required, and the coupling There is also a problem that a part that constitutes a mechanism for moving the lens is required, which is disadvantageous for space saving and low cost.

  Therefore, the present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide an image forming apparatus including a unit configured to be detachable from the apparatus body. Positioning and fixing the shaft-like member such as the shaft of the rotating body provided in the unit to the device main body without deteriorating the detachability of the unit or adopting a disadvantageous construction for space saving and low cost It is an object of the present invention to provide an image forming apparatus capable of doing so.

  In order to solve the above-described problems, an invention described in claim 1 is an image forming apparatus in which a unit having a shaft-like member is detachably attached to the apparatus main body. A recess for positioning and fixing is provided by fitting the shaft-shaped member, and the opening of the recess is slidable in a direction substantially perpendicular to the attaching / detaching direction of the unit, and the shaft-shaped member of the unit is A closing member for closing the opening is provided so as to prevent detachment, and the closing member slides by an operation accompanying the mounting operation of the unit to close the opening of the recess, and the closing member is a device. An image forming apparatus, wherein the image forming apparatus is engaged with a part of a main body and is prevented from moving in a direction in which the shaft-shaped member of the unit is detached.

  Further, the invention described in claim 2 is characterized in that the closing member slides in conjunction with an opening / closing operation of the cover when the unit is attached / detached to fix and open the shaft-like member. The image forming apparatus according to Item 1.

  Furthermore, the invention described in claim 3 is characterized in that the closing member is biased by a biasing means in a direction substantially perpendicular to the attaching / detaching direction of the unit when the shaft-like member of the unit is fixed. The image forming apparatus according to claim 1.

  According to a fourth aspect of the present invention, when the closing member moves in a direction to close the opening of the recess, the closing member is moved in a direction to contact the shaft-like member of the unit. The image forming apparatus according to claim 1, wherein the taper surface is provided on at least one of a surface in contact with the shaft-like member or a surface opposite to the contact surface.

  Furthermore, the invention described in claim 5 is characterized in that the closing member has a fixing shape for fixing the closing member in the vicinity of at least one of the openings of the recess. The image forming apparatus according to Item 1.

  Further, the invention described in claim 6 is characterized in that the closing member is fixed by being engaged with a member on the apparatus main body side located in the vicinity of at least one of the openings of the recess. An image forming apparatus according to claim 1.

  The image forming apparatus according to claim 1, wherein the unit is a process cartridge including at least one of a photosensitive member, an intermediate transfer member, and a developing roll. Device.

  The invention described in claim 8 is the image forming apparatus according to claim 1, wherein the unit is a fixing device.

  Further, the invention described in claim 9 is the image forming apparatus according to claim 1, wherein the unit is a unit including a transfer roll.

  According to the present invention, in an image forming apparatus including a unit configured to be detachable from the apparatus main body, a shaft-like member such as a shaft of a rotating body provided in the unit is deteriorated in detachability of the unit. In addition, it is possible to provide an image forming apparatus that can be positioned and fixed to the apparatus main body without adopting a configuration that is disadvantageous with respect to space saving and low cost.

  Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1
2 and 3 show a tandem full-color printer as an image forming apparatus according to Embodiment 1 of the present invention. In addition, the arrow in FIG. 3 has shown the rotation direction of each rotation member.

  As shown in FIGS. 2 and 3, the full-color printer 01 includes photosensitive drums (image carriers) 11, 12, 11 for yellow (Y), magenta (M), cyan (C), and black (K). 13, 14; primary charging charging rolls (contact type charging devices) 21, 22, 23, 24 in contact with the photosensitive drums 11, 12, 13, 14; yellow (Y), magenta (M), Laser optical unit 03 (exposure device) shown in FIG. 2 that irradiates laser beams 31, 32, 33, and 34 of cyan (C) and black (K), developing devices 41, 42, 43, and 44, and the above The first primary intermediate transfer drum (intermediate transfer body) 51 and the other two photosensitive drums 13 and 14 which are in contact with two of the four photosensitive drums 11, 12, 13 and 14. A second primary intermediate transfer drum (intermediate transfer body) 52 in contact with the first intermediate transfer drum 51 and a secondary intermediate transfer drum in contact with the first and second primary intermediate transfer drums 51 and 52. A ram (intermediate transfer member) 53 and a transfer roll (transfer member) 60 in contact with the secondary intermediate transfer drum 53 constitute the main part.

  As shown in FIG. 3, the photoconductor drums 11, 12, 13, and 14 are arranged at regular intervals so as to have a common tangential plane M.sub.2. Further, the first primary intermediate transfer drum 51 and the second primary intermediate transfer drum 52 are surfaces whose respective rotation axes are parallel to the photosensitive drums 11, 12, 13, and 14 and have predetermined target surfaces as boundaries. They are arranged in a symmetrical relationship. Further, the secondary intermediate transfer drum 53 is arranged so that the rotation axis thereof is parallel to the photosensitive drums 11, 12, 13, and 14.

  Signals corresponding to the image information for each color are rasterized by an image processing unit (not shown) and input to the laser optical unit 03 shown in FIG. In this laser optical unit 03, the laser beams 31, 32, 33, and 34 of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are modulated, and the corresponding photosensitive drums 11 , 12, 13 and 14.

  Around each of the photosensitive drums 11, 12, 13, and 14, an image forming process for each color is performed by a known electrophotographic method. First, as the photosensitive drums 11, 12, 13, and 14, for example, photosensitive drums (image carriers) using an OPC photosensitive member having a diameter of 20 mm are used, and these photosensitive drums 11, 12, 13, and 14 are used. For example, 14 is rotationally driven at a rotational speed of 95 mm / sec. As shown in FIG. 3, the surfaces of the photosensitive drums 11, 12, 13, and 14 are applied with a DC voltage of about -840V to charging rolls 21, 22, 23, and 24 as contact-type charging devices. For example, it is charged to about -300V. The contact-type charging device includes a roll type, a film type, a brush type, and the like, but any type may be used. In this embodiment, a charging roll generally used in an electrophotographic apparatus in recent years is employed. Further, in order to charge the surfaces of the photosensitive drums 11, 12, 13, and 14, in this embodiment, a charging method in which only DC is applied is used, but a charging method in which AC + DC is applied may be used.

  Thereafter, the surfaces of the photosensitive drums 11, 12, 13, and 14 correspond to yellow (Y), magenta (M), cyan (C), and black (K) colors by a laser optical unit 03 as an exposure apparatus. The laser beams 31, 32, 33, and 34 are irradiated, and an electrostatic latent image corresponding to input image information for each color is formed. When the electrostatic latent image is written by the laser optical unit, the photosensitive drums 11, 12, 13, and 14 are discharged to a surface potential of the image exposure portion of about −60 V or less.

  In addition, electrostatic latent images corresponding to yellow (Y), magenta (M), cyan (C), and black (K) colors formed on the surfaces of the photosensitive drums 11, 12, 13, and 14 Are developed by the developing devices 41, 42, 43, and 44 of the colors to be processed, and yellow (Y), magenta (M), cyan (C), and black (K) colors on the photosensitive drums 11, 12, 13, and 14, respectively. Visualized as a toner image.

  In this embodiment, as the developing devices 41, 42, 43, 44, a magnetic brush contact type two-component developing method is adopted, but the scope of application of the present invention is not limited to this developing method, Of course, the present invention can be sufficiently applied to other development systems such as a one-component development system and a non-contact development system.

The developing devices 41, 42, 43, and 44 are filled with yellow (Y), magenta (M), cyan (C), and black (K) toners of different colors and a developer composed of a carrier. Yes. When the toner is replenished from the toner cartridges 04Y, 04M, 04C, and 04K shown in FIG. 2, these replenishing devices 41, 42, 43, and 44 are sufficiently agitated with the carrier by the auger 404. Frictionally charged. Inside the developing roll 401, a magnet roll (not shown) having a plurality of magnetic poles arranged at a predetermined angle is fixed. By the paddle 403 that conveys the developer to the developing roll 401, the amount of the developer conveyed to the vicinity of the surface of the developing roll 401 is regulated by the developer amount regulating member 402. In this embodiment, the amount of the developer is 30 to 50 g / m ² , and the charge amount of the toner existing on the developing roll 401 at this time is approximately about −20 to 35 μC / g.

The toner used in the developing devices 41, 42, 43, 44 has a shape factor MLS2 defined by the following equation of 100 to 140, for example, MLS2 = 130, and an average particle size of 3 μm to 10 μm. So-called “spherical toner” is used.
MLS2 = {(absolute maximum length of toner particles) × 2)}
/ {(Projection area of toner particles) × π × 1/4 × 100}

  The toner supplied onto the developing roll 401 is in the form of a magnetic brush composed of a carrier and toner by the magnetic force of the magnet roll, and this magnetic brush comes into contact with the photosensitive drums 11, 12, 13, and 14. ing. A developing bias voltage of AC + DC is applied to the developing roll 401 to develop the toner on the developing roll 401 into an electrostatic latent image formed on the photosensitive drums 11, 12, 13, and 14. It is formed. In this embodiment, the developing bias voltage is about 4 kHz for AC, 1.5 kVpp, and about −230 V for DC.

  Next, the yellow (Y), magenta (M), cyan (C), and black (K) toner images formed on the respective photosensitive drums 11, 12, 13, and 14 are first primary images. The secondary transfer is electrostatically performed on the intermediate transfer drum 51 and the second primary intermediate transfer drum 52. The yellow (Y) and magenta (M) color toner images formed on the photoconductive drums 11 and 12 are formed on the first primary intermediate transfer drum 51 and cyan (on the photoconductive drums 13 and 14). The toner images of C) and black (K) are transferred onto the second primary intermediate transfer drum 52, respectively. Therefore, on the first primary intermediate transfer drum 51, the single color image transferred from either the photosensitive drum 11 or 12 and the two color toner images transferred from both the photosensitive drums 11 and 12 are superimposed. A double color image is formed. In addition, similar single-color images and double-color images are also formed on the second primary intermediate transfer drum 52 from the photosensitive drums 13 and 14.

  The surface potential necessary for electrostatically transferring the toner image from the photosensitive drums 11, 12, 13, 14 onto the first and second primary intermediate transfer drums 51, 52 is about +250 to 500V. It is. This surface potential is set to an optimum value depending on the charged state of the toner, the ambient temperature, and the humidity. The ambient temperature and humidity can be easily known by detecting the resistance value of a member having a characteristic that the resistance value varies depending on the ambient temperature and humidity. As described above, when the charge amount of the toner is in the range of −20 to 35 μC / g and is in a normal temperature and humidity environment, the surface potential of the first and second primary intermediate transfer drums 51 and 52 is + 380V is desirable.

The first and second primary intermediate transfer drums 51 and 52 used in this embodiment have an outer diameter of 42 mm, for example, and a resistance value of about 10 ⁸ Ω. The first and second primary intermediate transfer drums 51 and 52 are cylindrical rotating bodies having a single layer or a plurality of layers whose surfaces are flexible or elastic, and are generally made of Fe, Al, or the like. A low resistance elastic rubber layer (R = 10 ² to 10 ³ Ω) typified by conductive silicone rubber or the like is provided on a metal pipe as a metal core as described above to a thickness of about 0.1 to 10 mm. Further, the outermost surfaces of the first and second intermediate transfer drums 51 and 52 are typically high release layers (R = 10 ⁵ to 3) having a thickness of 3 to 100 μm of fluororubber in which fluororesin fine particles are dispersed. 10 ⁹ Ω) and bonded with a silane coupling agent-based adhesive (primer). What is important here is the resistance value and the releasability of the surface, and the resistance value of the high release layer is about R = 10 ⁵ to 10 ⁹ Ω. It is not limited.

The single-color or double-color toner images formed on the first and second primary intermediate transfer drums 51 and 52 in this way are electrostatically secondary-transferred onto the secondary intermediate transfer drum 53. Therefore, a final toner image from a single color image to a quadruple color image of yellow (Y), magenta (M), cyan (C), and black (K) is formed on the secondary intermediate transfer drum 53. It will be.

  The surface potential necessary for electrostatically transferring the toner image from the first and second primary intermediate transfer drums 51 and 52 onto the secondary intermediate transfer drum 53 is about +600 to 1200V. This surface potential is the same as when the toner is transferred from the photosensitive drums 11, 12, 13, 14 to the first primary intermediate transfer drum 51 and the second primary intermediate transfer drum 52. Will be set to the optimum value. Further, since what is necessary for the transfer is a potential difference between the first and second primary intermediate transfer drums 51 and 52 and the secondary intermediate transfer drum 53, the first and second primary intermediate transfer drums 51 and 52 have different potentials. It is necessary to set the value according to the surface potential. As described above, the charge amount of the toner is in the range of −20 to 35 μC / g, and the surface potential of the first and second primary intermediate transfer drums 51 and 52 is +380 V in a normal temperature and humidity environment. The surface potential of the secondary intermediate transfer drum 53 is about +880 V, that is, the potential difference between the first and second primary intermediate transfer drums 51 and 52 and the secondary intermediate transfer drum 53 is + It is desirable to set it to about 500V.

The secondary intermediate transfer drum 53 used in this embodiment is formed to have the same outer diameter as that of the first and second primary intermediate transfer drums 51 and 52, for example, 42 mm, and the resistance value is set to about 10 ¹¹ Ω. . Similarly to the first and second primary intermediate transfer drums 51 and 52, the secondary intermediate transfer drum 53 is a cylindrical rotating body having a single layer or a plurality of layers whose surface is flexible or elastic. In general, a low resistance elastic rubber layer (R = 10 ² to 10 ³ Ω) typified by conductive silicone rubber or the like is formed on a metal pipe as a metal core made of Fe or Al. It is provided at about 0.1-10mm. Further, the outermost surface of the secondary intermediate transfer drum 53 is typically formed by forming fluororubber in which fine particles of fluororesin are dispersed as a high release layer having a thickness of 3 to 100 μm, and a silane coupling agent-based adhesive (Primer). Here, the resistance value of the secondary intermediate transfer drum 53 needs to be set higher than that of the first and second primary intermediate transfer drums 51 and 52. Otherwise, the secondary intermediate transfer drum 53 will charge the first and second primary intermediate transfer drums 51, 52, making it difficult to control the surface potential of the first and second primary intermediate transfer drums 51, 52. Become. The material is not particularly limited as long as the material satisfies such conditions.

  Next, the final toner image from the single color image to the quadruple color image formed on the secondary intermediate transfer drum 53 is tertiary transferred onto the transfer paper 101 passing through the paper conveyance path by the final transfer roll 60. Is done. The transfer paper 101 passes through the registration roller 90 through a paper feeding process as shown in FIG. 3, and is fed into the nip portion between the secondary intermediate transfer drum 53 and the transfer roll 60. After this final transfer step, the final toner image formed on the transfer paper 101 is fixed by heat and pressure by the fixing device 70, and a series of image forming processes is completed.

  By the way, in this embodiment, in an image forming apparatus in which a unit having a shaft-shaped member is detachable with respect to the apparatus main body, positioning is performed by fitting the shaft-shaped member of the unit to the apparatus main body. A recess for fixing is provided, and the opening of the recess is slidable in a direction substantially perpendicular to the attaching / detaching direction of the unit, and the opening is provided so as to prevent the shaft-like member from being detached. A closing member is provided for closing, the closing member is slid by an operation accompanying the mounting operation of the unit, closes the opening of the recess, and the closing member engages with a part of the apparatus body; The unit is configured to be prevented from moving in a direction in which the shaft-like member is detached.

  Further, in this embodiment, the closing member is configured to slide in conjunction with the opening / closing operation of the cover when the unit is attached / detached to fix and open the shaft-like member.

  Furthermore, in this embodiment, the closing member is configured to be urged by the urging means in a direction substantially perpendicular to the attaching / detaching direction of the unit when the shaft-like member of the unit is fixed.

  Further, in this embodiment, when the closing member moves in the direction of closing the opening of the recess, the tapered surface moves the closing member in the direction of contacting the shaft-like member of the unit. It is comprised so that it may have in at least one of the surface which contacts a shaft-shaped member, or the surface on the opposite side to a contact surface.

  That is, in the full color printer 01 according to this embodiment, as shown in FIG. 4, in order to improve the maintainability and the like, the four photosensitive drums 11, 12, 13, 14 and the first and second primary intermediates are provided. The transfer drums 51 and 52 and the secondary intermediate transfer drum 53 are integrally provided to form an image forming unit 101. The image forming unit 101 is attached to and detached from the main body 102 of the full-color printer 01. It is free.

  As shown in FIG. 5, the image forming unit 101 has four photosensitive drums 11, 12, 13, 14 and first and second primary intermediate transfer drums 51, 52, Frames 103 and 104 for rotatably supporting the next intermediate transfer drum 53 are provided. Further, in the image forming unit 101, a rotating shaft 105 as a shaft-like member for rotatably supporting the secondary intermediate transfer drum 53 protrudes outward from the right and left frames 103, 104 by a predetermined amount. It is attached to do. The rotating shaft 105 of the secondary intermediate transfer drum 53 is positioned and fixed at a predetermined position when the image forming unit 101 is mounted on the main body 102 of the full-color printer 01, as shown in FIG. It serves as a fixing member for the purpose. The rotating shaft 105 for rotatably supporting the secondary intermediate transfer drum 53 may be any one that supports the secondary intermediate transfer drum 53 rotatably. The rotating shaft 105 itself is provided rotatably. It may be provided in a state fixed to the image forming unit 101. In this embodiment, the rotating shaft 105 is attached to the image forming unit 101 in a fixed state.

  In this embodiment, the image forming unit 101 includes four photosensitive drums 11, 12, 13, 14 and first and second primary intermediate transfer drums 51, 52 as shown in FIG. In addition to the secondary intermediate transfer drum 53, charging rolls 21, 22, 23, 24, and a refresher roll (not shown) are attached as necessary.

  As shown in FIG. 6, the image forming unit 101 includes a front unit 106 that covers the side of the apparatus main body 102 and a cover member 107 that covers the upper part of the apparatus main body 102 with respect to the apparatus main body 102 of the full-color printer 01. When the image forming unit 101 is lifted upward in the open state, the image forming unit 101 can be removed from the apparatus main body 102 as shown in FIG. The vertical direction along the direction.

  The frame 108 of the apparatus main body 102 of the full-color printer 01 is rotated by the secondary intermediate transfer drum 53 when the image forming unit 101 is attached to the apparatus main body 102 as shown in FIGS. A guide recess 110 is provided for positioning and fixing in a state where the shaft 105 is fitted. As shown in FIG. 1, the recess 110 provided in the frame 108 of the apparatus main body 102 is set such that the distance between both side surfaces 110a and 110b is larger than the diameter of the rotary shaft 105 of the secondary intermediate transfer drum 53. In addition, an inclined surface 110c inclined toward the other side surface 110a is provided in the middle of the one side surface 110b. Then, the rotation shaft 105 of the secondary intermediate transfer drum 53 fitted in the guide recess 110 is inserted from an opening 111 provided at the upper end of the recess 110, and one of the recesses 110 is inserted. Positioning and fixing are performed in contact with the side surface 110a and the other inclined surface 110c. At this time, the rotation shaft 105 of the secondary intermediate transfer drum 53 may be configured not to contact the bottom surface 110d of the recess 110, or may be positioned in a state of contacting the bottom surface 110d of the recess 110. You may comprise so that it may be fixed.

  Further, as shown in FIGS. 8, 16, and 17, the apparatus main body 102 of the full-color printer 01 includes an image forming unit 101 in the opening 111 of the recess 110 provided in the frame 108 of the apparatus main body 102. A stopper member 114 is provided as a closing member that closes the opening 110 so as to be slidable in a direction substantially perpendicular to the attaching / detaching direction and to prevent the rotation shaft 105 of the image forming unit 101 from being detached. As shown in FIG. 9, the stopper member 114 has a cylindrical boss 115 projecting from the inner surface thereof in a long hole 116 provided on the frame 108 side of the apparatus main body 101 as shown in FIG. By fitting, the image forming unit 101 is slidably attached in a direction substantially perpendicular to the attaching / detaching direction of the image forming unit 101. Further, as shown in FIG. 1, the front end portion 117 of the stopper member 114 is engaged with a fixing engaging portion 119 having a rectangular cross section provided on the frame 108 of the apparatus main body 102, and the stopper member 114 is prevented from moving upward, and is slidably supported by cooperating with the boss 115 described above. The fixing engaging portion 119 has an upper surface above the stopper member 114 by abutting the upper surface 121 of the stopper member 114 with the fixing surface 120 formed on the upper portion thereof in a state where the stopper member 114 is engaged. It is designed to prevent movement to. Further, the bottom surface 122 of the fixing engaging portion 119 is provided with a small protrusion 123 having a substantially arc-shaped cross section in order to reduce sliding resistance with the stopper member 114 and to move the stopper member 114 upward. It has been. Further, on the lower surface of the stopper member 114, as shown in FIG. 1, the distal end portion 117 of the stopper member 114 is engaged with the engaging portion 119 of the frame 108, and the recess 110 of the frame 108 is engaged. An inclined taper portion 130 that abuts on the surface of the rotating shaft 105 of the fitted image forming unit 101 is provided.

  The tapered portion 130 does not necessarily have to be provided below the stopper member 114, and may be configured to be received by the upper portion of the stopper member 114 or both the lower portion and the upper portion. Further, when the tapered portion 130 is provided on the upper portion of the stopper member 114, the tapered portion 130 does not directly contact the surface of the rotation shaft 105 of the image forming unit 101, and the tapered portion 130 does not contact the stopper member 114. As a result of acting so as to push down, the lower surface of the stopper member 114 comes into contact with the surface of the rotation shaft 105 of the image forming unit 101.

  On the other hand, as shown in FIGS. 9 and 11, the stopper member 114 is formed in a substantially elongated rectangular parallelepiped shape with synthetic resin or the like, and the rear end portion 125 of the stopper member 114 slides on the pressure member 126. It is held freely. Further, as shown in FIG. 9, the stopper member 114 is provided with its front end portion 117 protruding outward from the rear end portion 125. When the stopper member 114 is pushed in, the image forming unit is provided. The rotary shaft 105 of 101 can be positioned and fixed in a state of being fitted into the recess 110 of the frame 108 from above.

  More specifically, as shown in FIG. 12, the stopper member 114 has a distal end portion 117 protruding in a substantially L shape with respect to the main body portion 140, and the main body portion 140 is formed in a substantially rectangular parallelepiped shape. Has been. The main body 140 of the stopper member 114 is slidably held by the pressure member 126 as shown in FIG. Further, the pressure member 126 is formed in a substantially rectangular parallelepiped shape as shown in FIG.

  Further, as shown in FIGS. 9 and 11, a compression spring 127 that urges the stopper member 114 in a protruding direction is accommodated in the pressure member 126. Further, the rear end face 128 of the pressure member 126 is formed in an obliquely inclined shape as shown in FIG. 14, and the front unit 106 is closed as the front unit 106 is closed as shown in FIG. The unit 106 is configured to be pressed by a pressing member 129. Further, as shown in FIG. 9, a tension spring S is attached to the stopper member 114, and the stopper member 114 is pulled back when the front unit 106 is opened.

  In the above-described configuration, in the full-color printer 01 according to this embodiment, in the image forming apparatus including the unit configured to be detachable from the apparatus main body as follows, the shaft of the rotating body provided in the unit It is possible to position and fix the shaft-shaped member to the apparatus main body without deteriorating the operability of attaching and detaching the unit and adopting a configuration that is disadvantageous for space saving and low cost. .

  That is, in the full-color printer 01 according to this embodiment, when the image forming unit 101 is taken out from the apparatus main body 102 for maintenance of the image forming unit 101, replacement of the image forming unit 101, or the like, as shown in FIG. In addition, the image forming unit 101 is lifted upward and taken out from the apparatus main body 102 with the front unit 106 as a front cover of the full color printer 01 and the cover 107 above the full color printer 01 being opened.

  On the other hand, when the maintenance of the image forming unit 101, the replacement of the image forming unit 101, or the like is completed, and the new image forming unit 101 or the like is attached to the apparatus main body 102, the image forming unit 101 is reverse to the removal process. Is set down at a predetermined position in the apparatus main body 102 from above.

  At that time, the rotating shaft 105 provided in the image forming unit 101 is positioned in a state of being fitted into a recess 110 provided in the frame 108 of the apparatus main body 102 as shown in FIGS. Then, the upper cover 107 of the full color printer 01 is closed and the front unit 106 of the full color printer 01 is closed.

  Then, the pressing member 129 provided on the front unit 106 of the full-color printer 01 presses the end surface 128 of the pressing member 126 provided on the frame 108 of the apparatus main body 102, and the pressing member 126 is shown in FIG. As shown in FIG. 11, the stopper member 114 is biased in the protruding direction by the elastic force of the compression spring 127 disposed therein.

  As a result, as shown in FIG. 18, the stopper member 114 has its tip end portion 127 engaged with the engaging portion 119 provided on the frame 108 of the apparatus main body 102 and provided on the lower surface of the stopper member 114. The tapered portion is positioned in a state in which it is fitted in the recess 110 of the frame 108, and stops in a state of being in contact with the surface of the rotating shaft 105 of the image forming unit 101. In this state, the stopper member 114 is prevented from moving upward by the upper end surface 120 of the engaging portion 119, and when the image forming unit 101 is driven to rotate, the stopper member 114 is obliquely upward with respect to the rotation shaft 105 of the image forming unit 101. Even if a rotational moment acts, the stopper member 114 can reliably prevent the upward movement.

  Further, since the stopper member 114 has an inclined taper portion 130 in contact with the rotating shaft 105 of the image forming unit 101, as shown in FIG. 19, a stopper member 114 made of synthetic resin or the like, The friction coefficient with the rotating shaft 105 made of metal is small, and the component force in the direction to push back the stopper member 114 is not so large, and the pressing force of the compression spring 127 that presses the stopper member 114 is also the minimum necessary force. The compression spring 127 may be a weak spring.

  As described above, in the above-described embodiment, in the full-color printer 01 including the image forming unit 101 configured to be detachable from the apparatus main body 102, the rotation shaft 105 provided in the image unit 101 is attached to and detached from the image unit 101. It is possible to position and fix to the apparatus main body 102 without deteriorating the operability of the apparatus and adopting a configuration that is disadvantageous for space saving and low cost.

  In the above embodiment, the case where the photosensitive drum and the intermediate transfer member are mounted on the image forming unit 101 has been described. However, the image forming unit includes at least one of the photosensitive member, the intermediate transfer member, and the developing roll. Of course, the process cartridge may be included.

  Further, the unit may be a fixing device or a unit including a transfer roll.

  Furthermore, although the case where the shaft-like member is the rotation shaft of the intermediate transfer member has been described in the above embodiment, it is not always necessary to be the rotation shaft of the rotation member.

FIG. 1 is a perspective configuration diagram showing main parts of a full-color printer as an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing a full-color printer as an image forming apparatus according to Embodiment 1 of the present invention. FIG. 3 is a block diagram showing the image forming unit of the full-color printer as the image forming apparatus according to Embodiment 1 of the present invention. FIG. 4 is a block diagram showing an image forming unit of a full-color printer as an image forming apparatus according to Embodiment 1 of the present invention. FIG. 5 is a block diagram showing an image forming unit of a full-color printer as an image forming apparatus according to Embodiment 1 of the present invention. FIG. 6 is a block diagram showing a state in which the cover of the full-color printer as the image forming apparatus according to Embodiment 1 of the present invention is opened. FIG. 7 is a block diagram showing a state in which the cover of the full-color printer as the image forming apparatus according to Embodiment 1 of the present invention is opened. FIG. 8 is a block diagram showing the main part of the full-color printer as the image forming apparatus according to Embodiment 1 of the present invention. FIG. 9 is a plan view showing the main part of the full-color printer as the image forming apparatus according to Embodiment 1 of the present invention. FIG. 10 is a perspective configuration diagram showing the main part of the full-color printer as the image forming apparatus according to Embodiment 1 of the present invention. FIG. 11 is a perspective configuration diagram showing the main part of the full-color printer as the image forming apparatus according to Embodiment 1 of the present invention. FIG. 12 is a configuration diagram showing the stopper members. FIG. 13 is a configuration diagram showing the pressure members. FIG. 14 is a configuration diagram showing a state in which the stopper member and the pressure member are combined. FIG. 15 is a perspective configuration diagram showing the apparatus main body. FIG. 16 is a block diagram showing the apparatus main body. FIG. 17 is an enlarged perspective view showing a main part of the apparatus main body. FIG. 18 is an enlarged perspective view showing the operation of the main part of the apparatus main body. FIG. 19 is an explanatory view showing the operation of the main part of the apparatus main body.

Explanation of symbols

  101: Image forming unit, 105: Rotating shaft (axial member), 108: Frame of the apparatus main body, 110: Recess, 114: Stopper member (closing member)

Claims (9)

In the image forming apparatus in which the unit having the shaft-shaped member is configured to be detachable with respect to the apparatus body, the apparatus body is provided with a recess for positioning and fixing by fitting the shaft-shaped member of the unit. The opening of the recess is provided with a closing member that is slidable in a direction substantially perpendicular to the attaching / detaching direction of the unit and that closes the opening so as to prevent the shaft-like member from being detached. The closing member slides by the operation accompanying the mounting operation of the unit, closes the opening of the recess, and engages with a part of the apparatus main body so that the shaft-shaped member of the unit is detached. An image forming apparatus characterized in that movement in the direction to be prevented is prevented. The image forming apparatus according to claim 1, wherein the closing member slides in conjunction with an opening / closing operation of the cover when the unit is attached / detached to fix and open the shaft-like member. The image forming apparatus according to claim 1, wherein the closing member is urged by an urging unit in a direction substantially perpendicular to the attaching / detaching direction of the unit when the shaft-like member of the unit is fixed. When the closing member moves in the direction of closing the opening of the recess, a taper surface that moves the closing member in a direction of contacting the shaft-shaped member of the unit is a surface that contacts the shaft-shaped member or The image forming apparatus according to claim 1, wherein the image forming apparatus is provided on at least one of the surfaces opposite to the contact surface. The image forming apparatus according to claim 1, wherein the closing member has a fixing shape for fixing the closing member in the vicinity of at least one of the openings of the recess. The image forming apparatus according to claim 1, wherein the closing member is fixed by being engaged with a member on the apparatus main body side located in the vicinity of at least one of the opening portions of the recess. The image forming apparatus according to claim 1, wherein the unit is a process cartridge including at least one of a photosensitive member, an intermediate transfer member, and a developing roll. The image forming apparatus according to claim 1, wherein the unit is a fixing device. The image forming apparatus according to claim 1, wherein the unit is a unit including a transfer roll.

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