JP2006145588A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an image defect due to soiling on an electrifying wire by sufficiently cleaning the electrifying wire disposed in a photoreceptor drum unit. <P>SOLUTION: In the image forming apparatus 1 provided with the photoreceptor drum unit 2 having a frame 20 wherein a photoreceptor drum 21, the electrifying wire 23 for electrifying the outer peripheral surface of the photoreceptor drum 21, a cleaning member 27 for cleaning the electrifying wire 23 are arranged therein, and a developing unit 4 constituted as a separate unit from the photoreceptor drum unit 2, the cleaning member 27 is arranged at one end part of a lever member 29 extending in parallel in the longitudinal direction of the photoreceptor drum 21, and the electrifying wire 23 is cleaned by the cleaning member 29 which is slid with the operation of the lever member 23, and the lever member 29 is operated linked with the operation of the developing unit 4 when the unit 4 is attached/detached to/from one side part of the apparatus main body 1a in a horizontal direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophotographic image forming apparatus employing a corona discharge method, and more particularly to a cleaning technique for a charging wire formed on a photosensitive drum unit.

  Image forming apparatuses such as copiers, facsimile machines, and printers are provided with a photosensitive drum unit in which a photosensitive drum whose outer peripheral surface is coated with a photoconductive film and a charger for charging the photosensitive drum are integrally provided. ing. A charging wire for applying a high voltage to generate corona discharge is stretched on the charger of the photosensitive drum unit. If silica or toner floating in the apparatus adheres to the surface of the charging wire as a discharge product, uneven corona discharge occurs from the charging wire, and the surface of the photosensitive drum cannot be uniformly charged. This causes density unevenness during image formation, and further appears as image defects such as image unevenness and lines.

As means for cleaning the charging wire, for example, in Patent Document 1 and Patent Document 2, a photosensitive drum unit including a charger having a discharging member (charging wire) is inserted into and removed from the apparatus main body along the axial direction of the photosensitive drum. In connection with this, there has been proposed an image forming apparatus provided with a cleaning member that slides in contact with the discharge member. In these image forming apparatuses, since the discharge member can be cleaned by the cleaning member every time the photosensitive drum unit is inserted and removed, the discharge member can be easily cleaned, and it does not require an operator or the like (see Patent Document 1 and Patent Document 2). ).
Japanese Patent Laid-Open No. 6-149022 JP-A-8-6464

  Certainly, when the charging wire is to be cleaned, if the operator manually slides the cleaning member, the cleaning operation is troublesome, the operator forgets to clean, or the entire length of the charging wire is sufficient. It may not be cleaned. As described in Patent Document 1 and Patent Document 2 described above, the charging wire cleaning efficiency is performed in conjunction with the removal of the charging wire when another component is taken out from the apparatus main body. And from the viewpoint of improving workability.

  However, the image forming apparatuses described in Patent Document 1 and Patent Document 2 are configured such that when the photosensitive drum unit is inserted into and removed from the apparatus main body, the charging wire is cleaned in conjunction with this. However, the lifetime of the photosensitive drum disposed in the photosensitive drum unit is longer than the lifetime due to lack of toner in the developing device, and the replacement frequency is low. For this reason, in a configuration in which the charging wire is cleaned after the life of the photosensitive drum is reached, the charging wire cannot be sufficiently cleaned, and as a result, the above-described image defects may occur.

  In particular, in the image forming apparatus described in Patent Document 2, the photosensitive drum unit is assembled as a cartridge having a developing unit and a cleaning unit as a unit body in addition to the photosensitive drum and the charging wire. In conjunction with this, the charging wire is cleaned by the cleaning member. Therefore, it is necessary to take out the entire cartridge from the apparatus main body in order to replace the toner in the developing device, and the photosensitive drum in use is also replaced in accordance with the lack of toner, resulting in poor usage efficiency.

  Accordingly, the present invention relates to an image forming apparatus that solves the above-described conventional problems, and is intended to reduce image defects due to contamination of the charging wire by sufficiently cleaning the charging wire disposed in the photosensitive drum unit. Objective.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, according to the first aspect of the present invention, a photosensitive drum unit in which a photosensitive drum, a charging wire for charging the outer peripheral surface of the photosensitive drum, and a cleaning member for cleaning the charging wire are arranged in a frame, and the photosensitive drum unit are separate units. In the image forming apparatus comprising the developing unit configured as described above, the cleaning member is disposed at one end of a lever member extending in parallel with the longitudinal direction of the photosensitive drum, and is slid by operation of the lever member. The charging wire is cleaned, and the lever member is operated in conjunction with the developer unit being attached / detached horizontally from one side of the apparatus main body.

  According to a second aspect of the present invention, an engagement member is provided at at least one of the lever member and the developing unit.

  According to a third aspect of the present invention, the engaging member is made of an elastic body.

  5. The exposure head according to claim 4, further comprising a lens cleaning portion that slides in a state where the cleaning member is in contact with the lens surface of the exposure head and cleans the exposure head, and is slid by operation of the lever member. The lens surface is simultaneously cleaned.

  As effects of the present invention, the following effects can be obtained.

  With the configuration shown in claim 1, since the charging wire can be automatically and simultaneously cleaned when the developing unit is inserted / removed, the cleaning is not forgotten, and the cleaning frequency of the charging wire is reduced. It can be ensured sufficiently, and it is possible to prevent image defects due to contamination of the charging wire. In addition, since only the developing unit can be detached from the photosensitive drum unit and removed, and the members constituting the photosensitive drum unit can be used continuously, the use efficiency of each member is good.

  Since it was set as the structure shown in Claim 2, the number of parts of a member can be reduced and manufacturing cost can be reduced.

  Since the structure shown in claim 3 is adopted, even if the developing unit is operated vigorously, the engaging member is elastically deformed to absorb the impact and prevent the engaging member, the lever member, the developing unit, etc. from being damaged. Can do.

  According to the fourth aspect of the present invention, the charging wire and the lens surface of the exposure head can be simultaneously cleaned by one operation, and no other cleaning process is required, so that the working efficiency can be greatly improved. Further, since cleaning can be performed while the charging wire and the exposure head are fixed, it is possible to prevent each member from being damaged and dust or the like from adhering thereto.

  Next, the best mode for carrying out the invention will be described.

  FIG. 1 is a front sectional view showing an overall configuration of an image forming apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view of a photosensitive drum unit, FIG. 3 is a front sectional view of the photosensitive drum unit, and FIG. FIG. 5 is a side view of the engaging portion, FIG. 6 is a view showing the state of the lever unit in conjunction with the insertion / removal operation of the developing unit, and FIG. 7 is an engagement in another embodiment. FIG. 8 is a front sectional view of the engaging portion of FIG.

  First, the overall configuration of the image forming apparatus 1 is outlined below.

  As shown in FIG. 1, the image forming apparatus 1 is disposed above the paper feed cassette 6. In the image forming apparatus 1, a toner image in which image information is visualized is transferred onto the recording paper fed from the paper feed cassette 6, and after the toner image is fixed, the recording paper is transferred to the recording paper of the image forming apparatus 1. The paper is discharged to a paper discharge tray 7 provided at the upper portion through the main conveyance path 11. A reverse path 12 is formed outside the main transport path 11, and the reverse path 12 branches and merges with the main transport path 11. A photosensitive drum unit 2, an exposure unit 3, a developing unit 4, a fixing unit 5, and the like are arranged along the recording sheet conveyance path in the main conveyance path 11.

  The photosensitive drum unit 2 includes a photosensitive drum 21 having a photoconductive film on its outer peripheral surface as a photosensitive member, a charger 22 for charging the outer peripheral surface of the photosensitive drum 21, a cleaning device 24, and the like. The charging wire 23 stretched around the charger 22 corona discharges when a high voltage is applied, and uniformly applies a negative charge to the outer peripheral surface of the photosensitive drum 21. The cleaning device 24 collects toner and paper powder remaining without being transferred in the transfer process.

  The exposure unit 3 is disposed obliquely above the photosensitive drum 21, and in this embodiment, a fixed scanning type using an LED as an exposure unit is provided. In other words, an exposure head 31 in which light emitting points are arranged in a line as an exposure device is provided close to the photosensitive drum unit 2 so that its lens surface 32 faces the photosensitive drum 21. The exposure head 31 performs image exposure on the outer peripheral surface of the photosensitive drum 21 charged by the charger 22 based on the digitized image information, thereby removing the negative charge on the irradiated portion on the photosensitive drum 21 and statically. An electrostatic latent image is formed.

  The developing unit 4 includes a supply roller 41, a developing roller 42, a toner case 43, and the like. The supply roller 41 supplies the toner to the developing roller 42 while negatively charging the toner from the toner case 43 containing the toner. The developing roller 42 supplies toner to the photosensitive drum 21 on which the latent image is formed, and the toner adheres only to a portion where the negative charge on the photosensitive drum 21 is removed by static electricity.

  The developing unit 4 is configured to be insertable / removable along the axial direction of the photosensitive drum 21, and a pull-out grip 44 protrudes from the side wall 45 on the front side of the apparatus, and holds the grip 44. It is comprised so that insertion / removal work can be performed (refer FIG.4 and FIG.5). The side wall 45 pivotally supports the supply roller 41, the developing roller 42, and the like between parallel side walls (not shown).

  The recording paper that has passed through the developing unit 4 is sent to a nip portion between the transfer roller 81 and the photosensitive drum 21 that are disposed across the main conveyance path 11 so as to come into contact with the outer peripheral surface of the photosensitive drum 21. When a bias voltage is applied to the transfer roller 81 on the back side of the recording paper that is in close contact with the photosensitive drum 21, the negatively charged toner is transferred from the photosensitive drum 21 to the recording paper. The recording sheet to which the toner has been transferred is sent to the fixing unit 5 downstream of the main transport path 11.

  The fuser unit 5 includes a heat roller 51 and a press roller 52 disposed with the main conveyance path 11 interposed therebetween so as to be in pressure contact with the outer peripheral surface of the heat roller 51. Then, the recording paper is fed into the nip portion between the heat roller 51 and the press roller 52, and the recording paper after toner transfer is heated and pressurized to fix the toner image on the recording paper.

  Further, an opening / closing cover 10 for maintenance is provided on a front surface portion which is one side portion of the apparatus main body 1a, and the opening / closing cover 10 is attached so as to be rotatable up and down around a lower position of the apparatus main body 1a. (See FIG. 6). When maintenance is performed on the photosensitive drum unit 2 and the developing unit 4 inside the apparatus main body 1a, the opening / closing cover 10 is opened to open the front side of the apparatus main body 1a to expose the inside, and the photosensitive drum unit 2 and the developing unit are exposed. The unit 4 is configured to be attached to and detached from the apparatus main body 1a in a horizontal direction (hereinafter referred to as X direction) orthogonal to the recording paper conveyance direction. The lever member 29 disposed on the photosensitive drum unit 2 and the developing device unit 4 are engaged with each other at the end in the same direction via the engaging portion 9, and the developing device unit 4 is inserted into and removed from the apparatus main body 1a. In addition, the lever member 29 is configured to be interlocked. Details will be described later.

  Next, the configuration of the photosensitive drum unit 2 will be described in detail below.

  As shown in FIGS. 2 and 3, the photosensitive drum unit 2 is provided with a photosensitive drum 21 at the bottom, a charger 22 at the top, and an upper side of the charger 22 (rightward in FIG. 3). ) Is provided with a cleaning device 24. The frame 20 has an opening at the bottom, and the photosensitive drum 21 is rotatably supported by both side walls in the longitudinal direction of the frame 20 so as to be positioned directly below the charger 22. A charging wire 23 for corona discharge on the surface of the photosensitive drum 21 is supported by the charger 22 at both ends on the lower side of the frame 20 (the side on which the photosensitive drum 21 is disposed), and in the longitudinal direction of the frame 20. It is stretched along.

  The lower part of the photosensitive drum 21 is open to the outside without being covered by a member such as the frame 20, and the developing roller 42 and the transfer roller 81 of the developing unit 4 are placed on the outer peripheral surface of the photosensitive drum 21 in this open part. The toner is supplied and the transfer process is performed by the contact. The frame 20 extends along the circumferential surface of the photosensitive drum 21, and an opening 25b is opened in the longitudinal direction of the extending portion, and a part of the photosensitive drum 21 is exposed from the opening 25b. An exposure head 31 of the exposure unit 3 is disposed on the side of the photosensitive drum unit 2, and the lens surface 32 faces the outer peripheral surface of the photosensitive drum 21 through the opening 25b.

  An opening 25a is opened on the upper surface of the frame 20, and a cleaning member 27 for cleaning the charging wire 23 is slidably attached to the opening 25a. The cleaning member 27 of this embodiment is slid and cleaned while sandwiching the charging wire 23, and lens cleaning that is slid and cleaned in contact with the lens surface 32 of the exposure head 31. Part 27e.

  The cleaning member 27 is disposed through the opening 25 a in the vertical direction of the frame 20, and a vertical portion 27 b erected substantially vertically is formed on the outer side (upper side) of the frame 20. On the inner side (downward), a wire cleaning part 27c is formed that contacts the charging wire 23 from the lower surface of the horizontal part 27a through the opening 25a. A lever member 29 is fixed to the vertical portion 27b. The wire cleaning section 27c is provided with a cleaning tool 28a made of sponge or the like at the end, and the cleaning tool 28a is folded back approximately 180 degrees so as to sandwich the charging wire 23 therebetween, It is in contact with the part.

  The cleaning member 27 has a guide portion 27 d extending along the outer shape of the frame 20 in a direction substantially perpendicular to the axial direction of the photosensitive drum 21. The guide part 27d reaches the opening part 25b, and a lens cleaning part 27e is attached to the end part. The lens cleaning unit 27e is disposed in the opening so as to block a part of the opening 25b, and the cleaning tool 28b disposed in the lens cleaning unit 27e has a lens surface of the exposure head 31 directed to the opening 25b. 32 is in contact with a part of.

  The frame 20 is provided with a lever member 29 as an operating tool for sliding the cleaning member 27 back and forth along the longitudinal direction of the photosensitive drum 21. One end portion of the lever member 29 is detachably attached to the vertical portion 27 b, and the other end portion protrudes laterally through the side wall 20 a of the frame 20. Thus, the vertical portion 27b and the side wall 20a are supported substantially in parallel with the photosensitive drum 21, the charging wire 23, and the like. The other end of the lever member 29 is provided with a knob portion 29b formed so as to be larger than the axial radius of the lever member 29. By grasping the knob portion 29b, the operator can operate the lever member 29. Can be easily slid.

  When the lever member 29 is slid in the front-rear direction of the photosensitive drum unit 2, the cleaning member 27 is slid together with the lever member 29. By operating the lever member 29 relative to the photosensitive drum 21, the cleaning member 27 slides while simultaneously cleaning the charging wire 23 and the lens of the exposure head 31 by the wire cleaning unit 27c and the lens cleaning unit 27e. Can do.

  When the lever member 29 is pushed into the photosensitive drum unit 2, the cleaning member 27 is stopped in a state (home position) in contact with the rear end of the opening 25a. When the lever member 29 is gradually pulled out (in the X direction) from the photosensitive drum unit 2, the cleaning member 27 is slid along the opening 25a with respect to the lever member 29, and comes into contact with the front end of the opening 25a. Is stopped in the stopped state (end position).

  With the configuration described above, the cleaning member 27 disposed in the photosensitive drum unit 2 is slid by only one operation of the lever member 29, and the charging wire 23 and the lens surface 32 of the exposure head 31 can be cleaned simultaneously. Other cleaning processes are unnecessary, and work efficiency is greatly improved. Further, since the cleaning can be performed while the charging wire 23 and the exposure head 31 are fixed, it is possible to prevent each member from being damaged and dust or the like from adhering thereto.

  The lever member 29 is provided with a knob portion 29b and can be manually operated by the operator. However, the lever member 29 may be configured such that the lever member 29 cannot be manually operated. The shape of the cleaning member 27 is not limited to this, and for example, only one of the charging wire 23 and the lens surface 32 of the exposure head 31 may be cleaned.

  Next, the configuration of the engaging portion 9 will be described in detail below.

  As shown in FIGS. 4 to 6, in the image forming apparatus 1 in this embodiment, the lever member 29 and the developing unit 4 are connected to each other by an engaging portion 9 so that the developing unit 4 is connected to the main body of the apparatus. The lever member 29 is configured to slide in conjunction with insertion and removal from 1a (see FIG. 4). That is, as described above, the cleaning member 27 is configured to slide and clean the charging wire 23 and the like when the lever member 29 is operated in the front-rear direction along the axial direction of the photosensitive drum 21. Further, the lever member 29 is slid in conjunction with the engaging unit 9 when the developing unit 4 (toner case 43) is out of toner and is inserted into and removed from the apparatus main body 1a. It is configured to be operated dynamically.

  As shown in FIG. 5, the engaging portion 9 is formed at the end of the lever member 29 and the developing unit 4 on the opening / closing cover 10 side, specifically, the rear side surface of the knob portion 29 b of the lever member 29. The engaging member 91 extends downward from the side wall 45 and the engaging member 92 extends upward from the side wall 45 of the developing device unit 4. The engaging member 91 and the engaging member 92 are disposed at positions facing the sliding direction of the lever member 29 and are engaged between the lever member 29 and the developing device unit 4. That is, the engaging member 91 and the engaging member 92 are disposed at a position where at least a part thereof is overlapped when viewed from the front, and the engaging member 91 is disposed on the front side and the engaging member 92 is disposed on the rear side. Each of the engaging member 91 and the engaging member 92 is formed in a long plate shape, and is brought into contact with and engaged with each other substantially in parallel. However, the shapes of the engaging member 91 and the engaging member 92 are not limited to this, and the engaging protrusions are provided on the contact side surfaces of the engaging member 91 and the engaging member 92 so that the engaging members 91 and the engaging member 92 are more reliably engaged with each other. It may be.

  The engagement member 91 is separately attached to the rear side surface of the knob portion 29 b, while the engagement member 92 is separately attached to the front surface of the side wall 45. A known technique can be used as the attachment means of the engaging member 91 and the engaging member 92 as long as it is fixed to the knob portion 29b and the side wall 45 so that the relative position cannot be changed. In this embodiment, the engaging member 91 and the engaging member 92 are fixed by bonding. Further, the engaging member 91 and the engaging member 92 do not necessarily need to be engaged at a right angle, and the lever member 29 and the developer unit 4 move in conjunction with each other by engaging with each other. Any configuration may be used.

  As shown in FIG. 6A, the photosensitive drum unit 2 and the developing unit 4 are arranged in a direction perpendicular to the main transport path 11 and the like formed in the apparatus main body 1a, and are arranged in the photosensitive drum unit 2. The drum shaft of the photosensitive drum 21 and the roller shaft of the developing roller 42 disposed in the developing unit 4 are arranged so as to be substantially parallel to each other. In such a state, the engagement portion 9 does not matter whether the engagement member 91 and the engagement member 92 are in contact or non-contact.

  Next, as shown in FIG. 6B, when the developing device unit 4 is pulled out in the X direction from the front surface where the opening / closing cover 10 of the apparatus main body 1a is mounted, the engaging member is attached to the developing device unit 4. 92 engages with an engaging member 91 attached to the lever member 29, and the lever member 29 is also slid in the X direction in conjunction with the engaging member 91. At this time, since the cleaning member 27 is disposed at one end of the lever member 29, the charging wire 23 and the lens surface 32 of the exposure head 31 are cleaned by the sliding operation of the lever member 29. That is, when the developing device unit 4 is moved in the X direction, the cleaning member 27 is simultaneously moved through the lever member 29 to clean the charging wire 23 and the like.

  As shown in FIG. 6C, when the developing device unit 4 is pulled out from the apparatus main body 1a, the front portion of the developing device unit 4 is inclined downward, and the engaging member 91 and the engaging member 92 are eventually engaged. The state is canceled, and the lever member 29 stops in a state where the cleaning member 27 is located at the end position. By causing the cleaning member 27 to reach the end position, the charging wire 23 can be thoroughly cleaned over the entire length. Further, since the engaging member 91 and the engaging member 92 are in contact with each other, the lever member 29 can be cleaned by pulling it alone. In other words, the cleaning operation can be arbitrarily performed when the image becomes dirty.

  In this embodiment, the lever member 29 is configured to be interlocked when the developing unit 4 is mainly removed from the apparatus main body 1a. However, the present invention is not limited to this. For example, when the developing device unit 4 is attached to the apparatus main body 1a, the engaging member 91 and the engaging member 92 are engaged, and the lever member 29 is slid in conjunction with the engaging member 91 and the engaging member 92. The cleaning member 27 may be moved to the home position. In the case where the toner case 43 is replaced and the toner is replenished, the configuration in which the engaging member protrudes from the toner case 43 in the same manner as described above can be configured to obtain the same action.

  In general, the replacement life of the toner stored in the toner case 43 of the developing unit 4 is shorter than the replacement life of the photosensitive drum 21, that is, the developing unit 4 is replaced more frequently than the photosensitive drum unit 2. In this embodiment, paying attention to the toner replacement frequency of the developing unit 4, when the developing unit 4 is inserted into and removed from the apparatus main body 1 a, the cleaning member 27 is moved in conjunction with the charging wire 23 and the like. Is configured to be cleaned. With this configuration, it is not necessary for the operator to slide the lever member 29 one by one to clean the charging wire 23 and the like, and cleaning can be performed automatically and simultaneously when the toner is replaced. Never forget to clean the charging wire 23 and the like. Further, by configuring the charging wire 23 and the like to be cleaned when the toner is replaced, the charging frequency of the charging wire 23 and the like can be sufficiently ensured, and image defects and the like caused by contamination of the charging wire 23 can be prevented. it can.

  In particular, in this embodiment, the photosensitive drum unit 2 and the developing unit 4 are configured separately, and the lever unit 29 is operated by pulling the developing unit 4 relative to the photosensitive drum unit 2 out of them. It is configured. Therefore, when the toner in the developing unit 4 (toner case 43) is depleted, only the developing unit 4 can be separated from the photosensitive drum unit 2 and removed, and the members constituting the photosensitive drum unit 2 can be used continuously. Efficiency is good.

  The engaging portion 9 may be configured such that an engaging member is disposed only on the developing device unit 4 side and the engaging member is engaged with the knob portion 29b of the lever member 29, while the lever An engaging member may be disposed only on the member 29 side, and the engaging member may be engaged with the side wall 45 of the developing unit 4. That is, in the engaging portion 9, the engaging member is arranged at at least one end of the lever member 29 and the developing unit 4, and the engaging member is engaged with the other end. May be.

  As an example, in the image forming apparatus 1 shown in FIGS. 7 and 8, the engaging member 93 is attached only to the side wall 45 of the developing unit 4, and the engaging member 93 reaches the lever member 29 in the upward direction. It is extended toward the. The lower end portion of the engaging member 93 is attached to the side wall 45 with an adhesive or the like, and the upper end portion is formed with a substantially central portion of the edge portion recessed downward to form an abutting portion 93a. The abutment portion 93 a abuts against the shaft portion of the lever member 29 from below 29 c, is formed to be slidable in the front-rear direction along the lower surface of the shaft portion 29 c, and is a knob formed at the end portion of the lever member 29. It contacts the part 29b from the side.

  When the developing unit 4 is pulled out of the apparatus main body 1 a from the state in which the photosensitive drum unit 2 and the developing unit 4 are respectively installed in the apparatus main body 1 a, the contact portion 93 a of the engaging member 93 is connected to the lever member 29. The engaging member 93 and the knob member 29b of the lever member are engaged with each other by coming into contact with the knob portion 29b while being in sliding contact with the shaft portion 29c. When the developing unit 4 is pulled out in the X direction, the lever member 29 is also slid in the X direction in conjunction with it. When the developing unit 4 is pulled out from the apparatus main body 1a, the engaging member 93 is only in contact with the lever member 29. The container unit 4 can be taken out.

  As described above, even if the engaging member 9 is configured by providing an engaging member in at least one of the lever member 29 and the developing device unit 4 as described above, the lever member 29 is interlocked with the developing device unit 4 as described above. The number of parts of the member can be reduced, and thus the manufacturing cost can be reduced. As described above, the engaging member may be provided only in the lever member 29.

  In the above embodiment, the engaging members 91, 92, 93 are preferably formed of members (elastic bodies) having elastic force. As the elastic body, a leaf spring, an elastic resin, or the like can be used. By forming the engaging member 91 etc. by an elastic body, even if the developing unit 4 is vigorously inserted / removed, the engaging member 91 etc. is elastically deformed to absorb the impact, and the engaging member 91 etc. It is possible to prevent the lever member 29 and the developing device unit 4 from being damaged. Also, when the developing unit 4 is detached from the apparatus main body 1a, the engaging portion 9 does not get in the way if the engaging member is elastically deformed. When the engaging member 91 and the engaging member 92 are provided in both the lever member 29 and the developing unit 4 as in the above embodiment (see FIGS. 4 and 5), at least one of them is made of an elastic body. What is necessary is just to form.

1 is a front sectional view showing an overall configuration of an image forming apparatus according to an embodiment of the present invention. The perspective view of a photosensitive drum unit. FIG. 3 is a front sectional view of the photosensitive drum unit. The side view of a photosensitive drum unit and a developing device unit. The side view of an engaging part. The figure which shows the state of the lever member linked with this with the insertion / extraction operation of a developing device unit. The side view of the engaging part in another Example. FIG. 8 is a front sectional view of the engaging portion of FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1a Apparatus main body 2 Photosensitive drum unit 4 Developer unit 9 Engagement part 20 Frame 21 Photosensitive drum
27 Cleaning member 29 Lever member 91, 92, 93 Engaging member

Claims (4)

A photosensitive drum, a charging wire for charging the outer peripheral surface of the photosensitive drum, a photosensitive drum unit in which a cleaning member for cleaning the charging wire is disposed in a frame, and a developing unit configured as a separate unit from the photosensitive drum unit. In the image forming apparatus
The cleaning member is disposed at one end of a lever member extending parallel to the longitudinal direction of the photosensitive drum, and is slid by operation of the lever member to clean the charging wire.
2. The image forming apparatus according to claim 1, wherein the lever member is operated in conjunction when the developing unit is horizontally attached and detached from one side of the apparatus main body.   The image forming apparatus according to claim 1, wherein an engagement member is provided at at least one of the lever member and the developing unit. .
The image forming apparatus according to claim 2, wherein the engagement member is made of an elastic body.   The cleaning member includes a lens cleaning unit that slides in contact with the lens surface of the exposure head and cleans the lens, and is slid by operating the lever member to simultaneously clean the lens surface of the exposure head. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

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