JP2018005010A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leakage of toner from a gap between an image carrier unit and a developing unit.SOLUTION: An image forming apparatus 1 of the present invention comprises: photoreceptor units 31 that each include a photoreceptor drum 22; developing units 32 that each include a developing roller 24 provided so as to be freely contactable to and separable from the photoreceptor drum 22; operation levers 43 that are each operated to move the developing roller 24 in a contact/separation direction with respect to the photoreceptor drum 22; and cover members 41 that each are moved together with the developing roller 24 through the operation of the operation lever 43, close a gap between the photoreceptor unit 31 and developing unit 32 when the developing roller 24 is in contact or proximity with the photoreceptor drum 22, and open the gap when the developing roller 24 is separated from the photoreceptor drum 22.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image forming apparatus that forms an image on a recording sheet, and more particularly to a technique for closing a gap between an image carrier unit and a developing unit constituting the image forming apparatus.

  The image forming apparatus includes an image carrier unit having an image carrier (photoreceptor drum) and a developing unit having a developing roller. The developing roller approaches or contacts the image carrier, and The latent image formed on the surface is developed with toner on the surface of the developing roller. Both the image carrier unit and the developing unit are detachably provided on the main body of the image forming apparatus for replacement. Here, as shown in Patent Document 1 below, when the image carrier unit and the developing unit are detached from the apparatus main body, the image carrier and the developing roller are separated from each other, and the image carrier and the developing roller are damaged. Techniques for preventing this have been proposed.

JP 2009-288286 A

  Here, since the developing roller is disposed with a gap between the image carrier and the image carrier during image formation, a gap is also generated between the image carrier unit and the developing unit. For this reason, the toner leaks from the gap and is scattered in the apparatus main body, and the inside of the image forming apparatus may be stained by the toner. For this reason, it is desired to propose a technique for preventing toner leakage from the gap between the image carrier unit and the developing unit.

  SUMMARY An advantage of some aspects of the invention is that it prevents toner from leaking from a gap between an image carrier unit and a developing unit.

  An image forming apparatus according to an aspect of the present invention includes: an image carrier unit having an image carrier; a developing unit having a developing roller that supplies toner to the image carrier; and the contact and separation directions with respect to the image carrier. A moving mechanism for moving the developing roller; and when the developing roller is moved together with the developing roller by the moving mechanism and is in a predetermined approaching state in which the developing roller is close to the image carrier, the developing roller extends in the axial direction. A cover member that covers a gap between the image carrier unit and the development unit and opens the gap when the developing roller is in a predetermined separated state away from the image carrier. It is.

  According to the present invention, toner leakage from the gap between the image carrier unit and the developing unit can be prevented.

1 is a front sectional view showing a structure of an image forming apparatus according to a first embodiment of the present invention. It is a front view showing each process processing unit in the image forming apparatus. FIG. 5 is a perspective view showing each process processing unit in the image forming apparatus, and shows a state in which one developing unit is pulled out. FIG. 2A is a cross-sectional view showing a pair of photoconductor units and a developing unit in the first embodiment, and FIG. 2B is an enlarged cross-sectional view showing a photoconductor drum and a developing roller. (A) is sectional drawing which shows the state which spaced apart the developing roller of the developing unit in 1st Embodiment from the photoreceptor drum of a photoreceptor unit, (b) is a cross section which expands and shows a photoreceptor drum and a developing roller. FIG. It is a perspective view which shows the developing roller and supply roller of the developing unit in 1st Embodiment. It is a perspective view which expands and shows the edge part of the developing roller in 1st Embodiment. (A) is a perspective view showing a state in which the operation lever of the developing unit in the first embodiment is pushed, and (b) is a perspective view showing a state in which the operation lever of the developing unit is pulled out. FIG. 9 is a cross-sectional view showing a pair of photoconductor units and a developing unit in a second embodiment, and shows a state where a vertical gap is covered. FIG. 9 is a cross-sectional view showing a pair of photoconductor units and a developing unit in a second embodiment, showing a state where a vertical gap is opened. (A) is a perspective view which shows the state which pushed in the operation lever of the developing unit in 2nd Embodiment, (b) is a perspective view which expands and shows the vicinity of the pushed-in operation lever. (A) is a perspective view showing a state in which the operating lever of the developing unit in the second embodiment is pulled out, and (b) is an enlarged perspective view showing the vicinity of the pulled out operating lever. It is sectional drawing which shows the front panel in the image forming apparatus, a collection member, etc.

Embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>

  FIG. 1 is a front sectional view showing the structure of the image forming apparatus according to the first embodiment of the present invention. The image forming apparatus 1 is a multifunction machine having a plurality of functions such as a copy function, a printer function, a scanner function, and a facsimile function. The image forming apparatus 1 includes an operation unit 47, an image forming unit 12, a fixing unit 13, a paper feeding unit 14, an image reading unit 15, and the like.

  The image reading unit 15 includes a scanner that optically reads a document, and generates image data indicating an image of the document.

  For example, the image forming unit 12 forms an image indicated by the image data generated by the image reading unit 15 on the recording paper P supplied from the paper supply unit 14. The image forming unit 12 includes a magenta process processing unit 21M, a cyan process processing unit 21C, a yellow process processing unit 21Y, and a black process processing unit 21Bk. Each of the process units 21M, 21C, 21Y, and 21Bk includes a photosensitive drum 22, a charge eliminating unit that neutralizes the surface of the photosensitive drum 22, a cleaning unit that cleans the surface of the photosensitive drum 22, and the photosensitive drum 22. A charging unit that uniformly charges the surface of the photosensitive drum 22, an exposure device (LSU; Laser scanning units) 23 that exposes the surface of the photosensitive drum 22 to form an electrostatic latent image on the surface, and the surface of the photosensitive drum 22 Are provided with a developing unit 32 for developing the electrostatic latent image into a toner image, and a primary transfer roller 25. The developing unit 32 has a developing roller 24.

  In each of the process units 21M, 21C, 21Y, and 21Bk, the surface of the photosensitive drum 22 is neutralized and cleaned, the surface of the photosensitive drum 22 is uniformly charged and then exposed, and the surface of the photosensitive drum 22 is colored. An electrostatic latent image corresponding to the image of the color component is formed, and the electrostatic latent image on the surface of the photosensitive drum 22 is developed with the toner of the color component by supplying the toner with the developing roller 24, and is formed on the photosensitive drum 22. A toner image is formed, and the toner image is primarily transferred onto the intermediate transfer belt 26 by the primary transfer roller 25.

  The toner images on the surface of the respective photosensitive drums 22 are superimposed on the intermediate transfer belt 26 that is driven to rotate, and become a color toner image. The secondary transfer roller 27 transfers the color toner image formed on the surface of the intermediate transfer belt 26 from the paper supply unit 14 through the conveyance path 28 in the nip portion N between the secondary transfer roller 27 and the intermediate transfer belt 26. Secondary transfer is performed on the conveyed recording paper P. Thereafter, the fixing unit 13 fixes the toner image on the recording paper P by thermocompression bonding. The recording paper P on which the color image has been formed after the fixing process is completed is discharged to the discharge tray 29.

  Next, the process units 21M, 21C, 21Y, and 21Bkb in the image forming apparatus 1 will be described in more detail.

  FIG. 2 is a front side view showing each process processing unit 21M, 21C, 21Y, and 21Bkb. FIG. 3 is a perspective view showing each process processing unit 21M, 21C, 21Y, and 21Bkb. FIG. 4A is a cross-sectional view showing a pair of photoconductor units and a developing unit in the process processing section. FIG. 4B is an enlarged sectional view showing the photosensitive drum 22 and the developing roller 24.

  As shown in FIGS. 2 to 4, a photosensitive unit 31 having a photosensitive drum 22 and a developing unit 32 having a developing roller 24 are provided for each of the process units 21M, 21C, 21Y, and 21Bkb. . In addition to the photosensitive drum 22, the photosensitive unit 31 includes a static eliminating unit that neutralizes the surface of the photosensitive drum 22, a cleaning unit 33 that cleans toner remaining on the surface of the photosensitive drum 22, and the photosensitive drum 22. A charging unit 34 for charging the surface uniformly is provided. In addition to the developing roller 24, the developing unit 32 is provided with a toner containing portion 35 that contains toner, two screws 36 that circulate and convey the toner, a supply roller 37 that supplies toner to the developing roller 24, and the like. It has been. The developing roller 24 of the developing unit 32 approaches or contacts the photosensitive drum 22 of the photosensitive unit 31, and toner is supplied from the surface of the developing roller 24 to the surface of the photosensitive drum 22, so that the photosensitive drum 22 is supplied. The electrostatic latent image formed on the surface of the toner is developed with toner. In the present embodiment, it is assumed that the developing roller 24 is disposed close to the photosensitive drum 22 during image formation, but is in a non-contacting state.

  Here, in each of the process units 21M, 21C, 21Y, and 21Bkb, the photosensitive unit 31 and the developing unit 32 are provided in a replaceable manner. To replace the photosensitive unit 31 and the developing unit 32, the front panel (not shown) of the image forming apparatus 1 is opened, and the process processing units 21M, 21C, 21Y, and 21Bkb are exposed as shown in FIG. It is done in the state. For example, as shown in FIG. 3, one developing unit 32 is pulled out and removed, and a new developing unit 32 is inserted and mounted.

  When the developing unit 32 is removed, as shown in FIGS. 5A and 5B, the developing roller 24 is in a separated state in which the developing roller 24 is separated from the photosensitive drum 22 by a certain distance. It is said. Further, after the developing unit 32 is mounted, the developing unit 32 is brought into a state where the developing roller 24 has moved to the approaching state, as shown in FIGS.

  Therefore, when the developing unit 32 is replaced, the developing roller 24 and the photosensitive drum 22 do not rub against each other, and the surface of the developing roller 24 and the surface of the photosensitive drum 22 are not damaged. Further, the replacement of the photoconductor unit 31 can be performed in a state where the developing roller 24 is separated from the photoconductive drum 22, so that the developing roller 24 and the photoconductive drum 22 are damaged when the photoconductive unit 31 is attached or detached. There is nothing.

  By the way, since the developing roller 24 is disposed with a gap between the photosensitive drum 22 and the photosensitive drum 22 during image formation, a gap is also generated between the photosensitive unit 31 and the developing unit 32. For this reason, the toner leaks out from the gap and is scattered, and the toner may contaminate the inside of the main body 11 (FIG. 1) of the image forming apparatus 1 in particular.

  For example, in the state during image formation, a gap A extending in the axial direction of the developing roller 24 is formed between the photosensitive unit 31 and the developing unit 32 as shown in FIGS. Yes. Therefore, in the first embodiment, a belt-like cover member 41 extending in the axial direction of the developing roller 24 is provided on the developing roller 24 side, the gap A is closed by the belt-like cover member 41, and toner leaks from the gap A. Prevents sticking out and scattering.

  Next, the band-shaped cover member 41 will be described in detail. FIG. 6 is a perspective view showing the developing roller 24 and the supply roller 37 of the developing unit 32. FIG. 7 is an enlarged perspective view showing an end portion of the developing roller 24.

  As shown in FIG. 6, support bodies 42 are provided at both ends in the axial direction, which is the direction in which the rotation shafts of the developing roller 24 and the supply roller 37 extend. These supports 42 rotatably support the shaft 24 a of the developing roller 24, and support the supply roller 37 so as to be rotatable in contact with the developing roller 24.

  Further, the shaft 37 a of the supply roller 37 penetrates through each support body 42 and is rotatably supported by respective bearings provided on each support body 42. Each support 42 is rotatably supported by the main body 11 with the shaft 37a of the supply roller 37 as the center of rotation, and the pressing spring 425 (pressing member) rotates the developing roller 24 in the clockwise direction in FIG. It is urged in a direction approaching the photosensitive drum 22. As a result, as shown in FIGS. 4A and 4B, the developing roller 24 is moved in the clockwise direction around the shaft 37a of the supply roller 37 and approaches or contacts the photosensitive drum 22.

  Further, as shown in FIG. 7, both end portions of the shaft 24a of the developing roller 24 are respectively inserted into the holes 441 of the cover support plate 44, and each cover support plate 44 is supported by both end portions of the shaft 24a. At both upper ends of these cover support plates 44, both ends of a belt-like cover plate 44a extending in the axial direction and parallel to the shaft 24a are attached. A belt-like sheet 45 is attached to the shaft 24a so as to extend in the axial direction on the side portion 444 of the cover plate 44a. The sheet 45 is made of thermoplastic polyurethane. However, the material of the sheet 45 is not limited to this. For example, the sheet 45 can be formed of a PET film, a polyethylene sheet, or the like. The cover member 41 includes a cover support plate 44, a cover plate 44a, and a sheet 45. Each cover support plate 44 is positioned inside each support 42 in the axial direction, and can be rotated around the shaft 37 a of the supply roller 37 together with the developing roller 24 by each support 42. . Thus, the belt-like cover member 41 is always parallel to the shaft 24a of the developing roller 24 and close to the upper peripheral surface of the developing roller 24, and is supported in a non-contact state on the peripheral surface of the developing roller 24. .

  Further, the developing unit 32 is provided with an operation lever (operation member) 43. The operation lever 43 is supported by the developing unit 32 so as to be movable in the axial direction in parallel with the shaft 24 a of the developing roller 24. The operation lever 43 is provided so that it can be pushed in as shown in FIG. 8A and pulled out as shown in FIG. 8B along the axis 24a of the developing roller 24. Note that the operation lever 43 is not shown in FIGS. 4 (a), 4 (b) and 5 (a), 5 (b).

  Further, as shown in FIG. 6, the operation lever 43 is provided with two protrusions 43a. The protruding portion 43 a is arranged so that the protruding direction faces the developing roller 24. Each support 42 is provided with a swing cam 42 a that protrudes toward the operation lever 43.

  In the state where the operation lever 43 is pushed in the axial direction as shown in FIG. 8A, as shown in FIG. 6, the two protrusions 43a of the operation lever 43 have the swing cams 42a of the respective supports 42. On the other hand, the position of the protrusion 43a with respect to the operation lever 43 is set so as to be different in the axial direction.

  In this state, since the protrusion 43a and the swing cam 42a do not interfere with each other, the developing roller 24 biased in the direction approaching the photosensitive drum 22 by the biasing spring 425 is shown in FIG. As shown in (b), the support member 42 rotates clockwise about the shaft 37a of the supply roller 37, moves in a direction approaching the photosensitive drum 22, and is in the approaching state. .

  At this time, the band-shaped cover member 41 provided on the developing roller 24 side covers the range from the peripheral surface of the developing roller 24 to the peripheral surface of the photosensitive drum 22 and closes the gap A. That is, the cover member 41 is disposed at a position that covers the gap A between the developing roller 24 and the photosensitive drum 22 extending in the axial direction from above the developing roller 24 and the photosensitive drum 22 when in the approaching state. The As a result, the leakage and scattering of the toner from the developing unit 32 to the outside from the gap A are prevented.

  When the operation lever 43 is pulled out as shown in FIG. 8B, the operation in the axial direction is performed at a position where the two protrusions 43a of the operation lever 43 come into contact with the swing cam 42a of each support 42. The movement of the lever 43 stops. The operation lever 43 is provided with a stopper (not shown) that is engaged with a part of the casing of the developing unit 32 and stops the movement in the axial direction at the contact position.

  In this state, the two protrusions 43 a of the operation lever 43 interfere with the swing cams 42 a of the respective support bodies 42, and push the swing cams 42 a downward with a pressing force larger than the urging force of the pressing spring 425. At this time, each support 42 rotates counterclockwise (a direction away from the photosensitive drum 22) about the shaft 37 a of the supply roller 37 against the urging force of the pressing spring 425. For this reason, as shown in FIGS. 5A and 5B, the developing roller 24 rotates counterclockwise around the shaft 37a of the supply roller 37 together with the support members 42, and moves away from the photosensitive drum 22. The above separation state is established. At this time, as shown in FIG. 5B, the belt-like cover member 41 is separated from the peripheral surface of the photosensitive drum 22 and opens the gap A.

  Subsequently, when the operation lever 43 is further pulled out, the operation lever 43 is locked to a part of the casing of the developing unit 32 by the stopper as described above, so that the developing roller 24 remains separated from the photosensitive drum 22. 3, the developing unit 32 is pulled out from the apparatus main body 11. Thereby, the developing unit 32 can be detached without damaging the developing roller 24 and the photosensitive drum 22.

  Furthermore, when a new developing unit 32 is inserted and mounted, the developing unit 32 is inserted into the apparatus main body 11 with the developing roller 24 shown in FIGS. After the insertion, when the operation lever 43 is pushed to the position shown in FIG. 8A, the two protrusions 43a of the operation lever 43 do not interfere with the swing cams 42a of the respective supports 42 as shown in FIG. Move to position. At this time, each support body 42 is again pressed by the pressing spring 425, and the developing roller 24 rotates clockwise about the shaft 37a of the supply roller 37, so that FIGS. To the position shown in FIG. In this state, the belt-like cover member 41 closes the gap A and returns to a state in which toner leakage and scattering from the gap A are prevented. In addition, the support body 42, the push spring 425, and the operation lever 43 are an example of the moving mechanism in a claim.

As described above, in the first embodiment, when the operation lever 43 of the developing unit 32 is pushed in as described above, the gap A is closed by the belt-shaped cover member 41, so that the toner leaks and scatters from the gap A. Is prevented. Further, when the operation lever 43 is pulled out as described above, the developing roller 24 and the cover member 41 are separated from the peripheral surface of the photosensitive drum 22, so that the developing unit is not damaged without damaging the developing roller 24 and the photosensitive drum 22. 32 can be exchanged. As described above, the developing roller 24 and the photosensitive drum 22 are damaged by detaching the photosensitive unit 31 from the apparatus main body 11 in a state where the developing roller 24 and the cover member 41 are separated from the peripheral surface of the photosensitive drum 22. It is possible to replace the photosensitive drum 22 without causing it to occur.
Second Embodiment

  Next, an image forming apparatus according to a second embodiment of the present invention will be described. 9 and 10 show the image forming apparatus 1 of the second embodiment. FIG. 9 is a cross-sectional view showing a pair of the photosensitive unit 31 and the developing unit 32, showing a state in which the vertical gap B is closed, and FIG. 10 shows that the vertical gap B is opened. Indicates the state.

  Similar to the first embodiment, the image forming apparatus 1 of the second embodiment has a configuration as shown in FIGS. The image forming apparatus 1 according to the second embodiment does not cover the gap A extending from the upper side in the axial direction of the developing roller 24 as in the first embodiment. In the image forming apparatus 1 according to the second embodiment, the gap B (FIG. 9) generated below the developing roller 24 and the photosensitive drum 22 at the end portions in the axial direction of the developing roller 24 and the photosensitive drum 22 is the gap B. Is covered from the side in the axial direction. The gap B extends in the axial direction of the developing roller 24 and extends in the vertical direction perpendicular to the axial direction of the developing roller 24.

  As shown in FIGS. 9 and 10, in the image forming apparatus 1 according to the second embodiment, a vertical gap B perpendicular to the axial direction of the developing roller 24 is formed between the photosensitive unit 31 and the developing unit 32. Has been. The gap B is formed between the frame of the photosensitive unit 31 and the frame of the developing unit 32, and has a shape along the outer periphery of each frame.

  The development unit 32 is provided with a cover member 51. The cover member 51 includes a bent portion 51a, an arm portion 51b, and a coil pressing spring 51c. Then, the guide pin 54 protruding from the frame of the developing unit 32 is inserted into the lateral groove 51d formed in the arm portion 51b of the cover member 51, and the arm portion 51b of the cover member 51 moves in the lateral direction. It is supported freely. Further, the coil pressing spring 51c is compressed between the left end of the lateral groove 51d and the guide pin 54, and the arm 51b is urged away from the photoreceptor unit 31 by the coil pressing spring 51c. Yes. In addition, the bending part 51a and the arm part 51b are an example of the cover member main body in a claim. The coil pressing spring 51c is an example of a pressing member in the claims.

  Here, the movement of the cover member 51 in the contact / separation direction (lateral direction) with respect to the photosensitive unit 31 will be described. The movement of the cover member 51 in the contact / separation direction (lateral direction) is interlocked with the push / pull operation of the operation lever (operation member) 43. Note that the operation lever 43 is not shown in FIGS. 9A and 9B and FIGS. 10A and 10B.

  FIG. 11A is a perspective view showing the developing unit 32 in a state where the operation lever 43 is pushed in, and FIG. 11B is an enlarged perspective view showing the vicinity of the pushed operation lever 43. FIG. 12A is a perspective view showing the developing unit 32 in a state where the operation lever 43 is pulled out, and FIG. 12B is an enlarged perspective view showing the vicinity of the pulled out operation lever 43. is there.

  As shown in FIGS. 11A and 11B and FIGS. 12A and 12B, the operating lever 43 is movable in parallel with the shaft 24a of the developing roller 24 (FIG. 4A), and the casing of the developing unit 32. Is supported by a part of. The operating lever 43 is formed with a protruding portion 53a that protrudes toward the arm portion 51b.

  11A and 11B, when the operation lever 43 is pushed in, the protrusion 53a of the operation lever 43 is disposed at a position where it abuts on the arm portion 51b of the cover member 51 in the axial direction. It is comprised so that. In a state where the protrusion 53a and the arm part 51b do not contact each other, the cover member 51 is biased in a direction away from the coil pressing spring 51c, but the protrusion 53a contacts the arm part 51b and the protrusion 53a. However, when the arm portion 51b is urged in a direction approaching the photosensitive drum 22 with a pressing force larger than the pressing force to the cover member 51 by the coil pressing spring 51c, the pressing force of the coil pressing spring 51c is resisted. The arm portion 51 b of the cover member 51 is moved in a direction approaching the photosensitive unit 31. At this time, the protrusion 53 a pushes and moves the cover member 51 to a position where the inner periphery of the bent portion 51 a of the cover member 51 contacts the outer periphery of the frame 31 a of the photoconductor unit 31. Accordingly, the bent portion 51a covers the upper half of the gap B between the photosensitive unit 31 and the developing unit 32 at the end of the gap B in the axial direction and shields the gap B in the axial direction.

  In FIG. 9, the arm portion 51 b of the cover member 51 is moved in the direction approaching the photosensitive unit 31 against the elastic force of the coil pressing spring 51 c, and the inner periphery of the bent portion 51 a is the photosensitive unit 31. The upper half of the gap B between the photosensitive unit 31 and the developing unit 32 is closed by the bent portion 51a in contact with the outer periphery of the frame 31a.

  12A and 12B, when the operation lever 43 is pulled out, the protrusion 53a of the operation lever 43 moves to a position away from the arm portion 51b in the axial direction. Accordingly, the protrusion 53a does not press the arm portion 51b in the direction approaching the photosensitive drum 22, so that the arm portion 51b of the cover member 51 is separated from the photosensitive unit 31 by the pressing force of the coil pressing spring 51c. Move to. By this movement, the inner periphery of the bent portion 51 a of the cover member 51 is separated from the outer periphery of the frame 31 a of the photoconductor unit 31. Therefore, the upper half of the gap B between the photosensitive unit 31 and the developing unit 32 is opened at the end of the gap B in the axial direction.

  In FIG. 10, the arm portion 51b is moved away from the photoreceptor unit 31 by the urging force of the coil pressing spring 51c, and the inner periphery of the bent portion 51a is separated from the outer periphery of the frame 31a of the photoreceptor unit 31. The upper half of the gap B between the body unit 31 and the developing unit 32 is open.

  In the second embodiment, the operation lever 43 has the same configuration as that of the first embodiment. That is, the operation lever 43 has two protrusions 43a as shown in FIG. 6 as in the first embodiment. In the state where the operation lever 43 is pushed in, the two protrusions 43a of the operation lever 43 are separated from the swing cams 42a of the respective supports 42, and the developing roller 24 is centered on the shaft 37a of the supply roller 37. It is biased clockwise and approaches or contacts the photosensitive drum 22. In the state where the operation lever 43 is pulled out, the two protrusions 43 a of the operation lever 43 come into contact with the swing cam 42 a of each support 42, and each support 42 is supported by the two protrusions 43 a of the operation lever 43. The support cam 42 is rotated counterclockwise around the shaft 37a of the supply roller 37 against the urging force of the push spring 425, and accompanying this, the support cam 42a is pushed downward. The developing roller 24 also rotates counterclockwise about the shaft 37 a of the supply roller 37, and the developing roller 24 is separated from the photosensitive drum 22.

  Accordingly, when the operation lever 43 is pushed in as described above, the upper half of the gap B is closed by the bent portion 51a of the cover member 51, and the developing roller 24 approaches or contacts the photosensitive drum 22, and the operation is performed. When the lever 43 is pulled out, the upper half of the gap B is opened and the developing roller 24 is separated from the photosensitive drum 22.

  Therefore, by pulling out the operation lever 43, the developing roller 24 can be separated from the photosensitive drum 22, and the developing unit 32 can be pulled out without damaging the developing roller 24 and the photosensitive drum 22.

  As described above, in the second embodiment, when the operation lever 43 of the developing unit 32 is pushed in, the upper half of the gap B is closed by the bent portion 51a of the cover member 51, so that the toner leaks from the upper half of the gap B. In addition, scattering is prevented. Further, when the operation lever 43 is pulled out, the developing roller 24 is separated from the peripheral surface of the photosensitive drum 22, so that the developing unit 32 can be replaced without damaging the developing roller 24 and the photosensitive drum 22. The photoconductor unit 31 can be replaced in the same procedure.

  Also in the second embodiment, the developing unit 32 may include the support 42, the push spring 425, and the operation lever 43 as a moving mechanism. In this case, when the operation lever 43 is pushed in as described above, the upper half of the gap B is covered by the bent portion 51a of the cover member 51, and the upper part of the gap A is also covered by the cover plate 45, so that the developing roller 24 is photosensitive. The approaching state is reached with respect to the body drum 22. Further, when the operation lever 43 is pulled out, the upper half of the gap B and the upper part of the gap A are opened, and the developing roller 24 is separated from the photosensitive drum 22.

  On the other hand, the lower half of the gap B between the photosensitive unit 31 and the developing unit 32 is closed by a collecting member provided inside the front panel provided in the apparatus main body 11 of the image forming apparatus 1.

  FIG. 13 is a cross-sectional view illustrating the front panel, the collecting member, and the like of the image forming apparatus 1. As shown in FIG. 13, a toner recovery box 62 is provided on the inner surface of the front panel 61 of the image forming apparatus 1. When the front panel 61 is closed, the toner collection box 62 is connected to the end of the photoconductor unit 31 of each process processing unit 21M, 21C, 21Y, and 21Bk, and the cleaning unit of each photoconductor unit 31 is connected. The toner collected by 33 is received from the cleaning unit 33 of each photoconductor unit 31 and collected, and this toner is stored. When the toner collection box 62 is full of toner, the front panel 61 is opened and the toner collection box 62 is replaced with a new one. When the front panel 61 is closed, a new toner collection box 62 is connected to the end of the photosensitive unit 31 of each process processing unit 21M, 21C, 21Y, and 21Bk.

  Further, as shown in FIGS. 9, 10, and 13, each portion of the toner collection box 62 that faces (opposites) the lower half of the gap B between the process processing units 21M, 21C, 21Y, and 21Bk. The respective collecting members 63 are provided. These collection members 63 are made of, for example, an expandable synthetic resin having elasticity.

  In a state where the front panel 61 of the image forming apparatus 1 is closed, each collecting member 63 is overlapped with the lower half of the gap B of each process processing unit 21M, 21C, 21Y, and 21Bk, and below the gap B. Close the side half. Thereby, the leakage and scattering of the toner from the lower half of the gap B are prevented.

  Therefore, in the second embodiment, when the operation lever 43 of the developing unit 32 is pushed in, the upper half of the gap B is closed by the bent portion 51a of the cover member 51, and the front panel 61 of the image forming apparatus 1 is closed. The lower half of the gap B is closed by the collecting member 63. In other words, the gap B covers and shields the side end of the gap B in the axial direction by the bent portion 51 a of the cover member 51 and the collecting member 63. This prevents the toner from leaking or scattering from the gap B. As described above, the collecting member 63 is made of, for example, a foamable synthetic resin and absorbs the toner, so that it also serves to collect the toner.

  Further, the configuration and processing described with reference to FIGS. 1 to 13 are merely an embodiment of the present invention, and the present invention is not intended to be limited to the configuration and processing.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 22 Photosensitive drum 24 Developing roller 31 Photosensitive unit 32 Developing unit 37 Supply roller 41, 51 Cover member 43 Operation lever 63 Collection member 425 Push spring

Claims (6)

An image carrier unit having an image carrier;
A developing unit having a developing roller for supplying toner to the image carrier;
A moving mechanism for moving the developing roller in the contact / separation direction with respect to the image carrier;
The image carrier unit that is moved together with the developing roller by the moving mechanism and extends in the axial direction of the developing roller when the developing roller is in a predetermined approach state that is close to the image carrier. An image forming apparatus comprising: a cover member that covers a gap of the developing unit and opens the gap when the developing roller is in a predetermined separated state away from the image carrier.   The cover member includes a band-shaped member extending in the axial direction along the peripheral surface of the developing roller, and the moving mechanism is configured to form the gap extending in the axial direction when the developing roller is in the approaching state. Further, it is disposed at a position that further covers a gap generated above the developing roller and the image carrier from above, and is disposed at a position that opens the upper portion when the developing roller is in the separated state. 2. The image forming apparatus according to 1.   The cover member extends along a peripheral surface of the image carrier, and is provided at an end portion in the axial direction of the developing roller and the image carrier, and the developing roller is in the approaching state by the moving mechanism. Sometimes, the gap extending in the axial direction, which is formed below the developing roller and the image carrier, is disposed at a position that covers an end of the gap in the axial direction from the side. The image forming apparatus according to claim 1, wherein the image forming apparatus is disposed at a position where a side of the end in the axial direction is opened when the roller is in the separated state. The cover member is
A cover member main body at least a part of which is disposed on the side of the end in the axial direction;
A pressing member that presses the cover member main body in a direction away from the image carrier in the contact / separation direction;
The cover member main body approaches the image carrier in the contact / separation direction against the pressing by the pressing member when it is movable in the axial direction and moved to a predetermined position in the axial direction. 4. The image according to claim 3, further comprising an operation member that is pressed in a direction to move the cover member main body to a position that covers the end of the gap in the axial direction from the side. 5. Forming equipment. The cover member body covers a part of the gap from the side at the end in the axial direction,
At the end in the axial direction, a collecting member that covers the other part of the gap that is not covered by the cover member main body is opposed to the end of the image carrier unit and the end of the developing unit in the axial direction. The image forming apparatus according to claim 4, wherein the image forming apparatus is provided in a toner collection box disposed in a manner.   The image forming apparatus according to claim 1, wherein the developing unit is configured to be detachable from an apparatus main body of the image forming apparatus when the developing roller is in the separated state.