This application is based on and claims the benefit of priority from Japanese patent application No. 2020-165053 filed on Sep. 30, 2020, which is incorporated by reference in its entirety.
The present disclosure relates to a development device attachable to and detachable from an apparatus main body and an image forming apparatus including the development device.
In the image forming apparatus, in many cases, the development device is attached to or detached from the apparatus main body along a predetermined inserting/drawing direction. Such a development device is provided with a lever member which is held by an operator when the development device is attached to or detached from the apparatus main body. For example, the handle (the lever) of the development tank (the development device) may be connected to a locking means for restricting the drawing of the development tank, and the locking means may be released by lifting the handle.
Further, the lever member may be provided with a hook portion which is engaged with a recess of the apparatus main body to restrict the drawing of the development device. In this case, in the process of attachment of the development device to the apparatus main body, the hook portion interferes with the apparatus main body to shift the lever member in a direction crossing to the attachment direction, and when the hook portion reaches the recess, the lever member is biased by a spring member to engage the hook portion with the recess. By shifting the lever member in a direction opposite to the above shift direction, the engagement between the hook portion and the recess is released, and it becomes possible to draw the development device out from the apparatus main body.
However, since the above-described lock means is configured to release an engagement between a lock claw and a projecting piece of the apparatus main body by turning a lock lever interlocking with the handle, there is a problem that the number of members and the number of assembling steps are increased. Further, even in a case where the hook portion is provided in the lever member, since the lever member needs to be supported via the spring member, there is a problem that the number of members and the number of assembling steps are increased.
In accordance with an aspect of the present disclosure, a development device is attachable to and detachable from an apparatus main body in a predetermined inserting/drawing direction. The development device includes a holder portion, a hook, a lever portion, and at least one elastic arm portion. The holder portion supports a board connectable to a controller of the apparatus main body. The hook is engageable with a recess of the apparatus main body. The lever portion is provided with the hook. At least one elastic arm portion connects the holder portion and the lever portion. In a middle of an attachment to the apparatus main body, the hook interferes with the apparatus main body to shift the lever portion in a direction crossing the inserting/drawing direction and to elastically deform the elastic arm portion. When the hook is engaged with the recess, the elastic deformation of the elastic arm portion is released and the board is connected to the controller.
In accordance with an aspect of the present disclosure, an image forming apparatus includes an image forming part which forms a toner image on the sheet by the development device 1.
The other features and advantages of the present disclosure will become more apparent from the following description. In the detailed description, reference is made to the accompanying drawings, and preferred embodiments of the present disclosure are shown by way of example in the accompanying drawings.
Hereinafter, with reference the attached drawings, an image forming apparatus and a development device according to one embodiment of the present disclosure will be described.
First, with reference to
The image forming apparatus 1 includes an apparatus main body 3 having a substantially rectangular parallelepiped inner space. In the lower portion of the apparatus main body 3, a sheet feeding cassette 5 is stored. The sheet feeding cassette 5 is attachable to and detachable from the apparatus main body 3 along the front-and-rear direction. On the upper surface of the apparatus main body 3, a discharge tray 7 is formed.
In the inner space of the apparatus main body 3, a sheet feeding part 9 disposed above the sheet feeding cassette 5, an image forming part 11 disposed above the sheet feeding part 9, a fixing part 13 disposed above the image forming part 11, and a discharge part 15 disposed above the fixing part 13 are provided. The image forming part 11 includes an exposure device 19, an intermediate transfer unit 21, four image forming units 23, four toner containers 25, and a secondary transfer roller 27.
The intermediate transfer unit 21 includes an endless intermediate transfer belt 31 and four primary transfer rollers 33 disposed in the hollow space of the intermediate transfer belt 31. The intermediate transfer belt 31 is stretched between a driving roller and a driven roller disposed at an interval in the left-and-right direction, and travels in a predetermined direction. The four primary transfer rollers 33 are disposed along the traveling direction of the intermediate transfer belt 31 so as to face the lower side traveling area of the intermediate transfer belt 31.
Each image forming unit 23 includes a photosensitive drum 35 rotating in a predetermined rotating direction, a charging device 37, a development device 39, and a cleaning device 41 which are disposed around the photosensitive drum 35 in the rotating direction of the photosensitive drum 35. The four image forming units 23 are disposed along the traveling direction of the intermediate transfer belt 31 so as to face the lower side traveling area of the intermediate transfer belt 31 from the lower side. The photosensitive drum 35 of each image forming unit 23 faces the primary transfer roller 33 via the intermediate transfer belt 31 between the development device 39 and the cleaning device 41. The four toner containers 25 contain developer (toner) of four colors (yellow, magenta, cyan and black) and are connected to the development devices 39 of the respective image forming units 23.
The secondary transfer roller 27 is disposed so as to face the intermediate transfer belt 31, and a transfer nip area 43 is formed between the intermediate transfer belt 31 and the secondary transfer roller 27. Further, in the inner space of the apparatus main body 3, a sheet conveyance path 45 along which the sheet is conveyed from the sheet feeding part 9 to the discharge part 15 through the transfer nip area 43 and the fixing part 13 is formed.
An image forming operation will be described. When an image forming instruction is received, the photosensitive drum 35 of each image forming unit 23 of the image forming part 11 is charged by the charging device 37. The exposure device 19 irradiates the charged photosensitive drum 35 with a laser beam to form an electrostatic latent image on the photosensitive drum 35. The electrostatic latent image is developed into a toner image by the development device 39 with the toner supplied from the toner container 25. The toner image is transferred from the photosensitive drum 35 to the intermediate transfer belt 31 by the primary transfer roller 33. By the four image forming units 23, the toner images of the four colors are superposed on the intermediate transfer belt 31 to form a full-color toner image. On the other hand, the sheet is fed from the sheet feeding cassette 5 by the sheet feeding part 9, and is conveyed along the conveyance path 45 to the transfer nip area 43. The toner image is transferred from the intermediate transfer belt 31 to the sheet at the transfer nip area 43, and fixed to the sheet in the fixing part 13. The sheet is discharged by the discharge part 15 and stacked on the discharge tray 7.
Next, with reference to
The development device 39 includes a magnet roller 51, an agitating roller, a supply roller (both rollers are not shown), and a housing 53 in which they are stored. The development device 59 is attachable to and detachable from the apparatus main body 3 in an inserting/drawing direction (the front-and-rear direction).
The housing 53 has a long shape in the inserting/drawing direction, and has a rear end part 53R on the downstream side (the rear side) in the inserting direction, a front end part 53F on the upstream side (the front side) in the inserting direction, and an enclosure part 53C between both the end parts 53R and 53F.
The rear end part 53R supports the rear end portions of the rotating shafts of the magnet roller 51, the agitating roller and the supply roller in a rotatable manner. Further, the rear end part 53R is provided with a roller driving part connected to a driving source provided in the apparatus main body 3, a toner replenishment part to which the toner is replenished from the corresponding toner container 25, and a waste toner collection part connected to a waste toner collection container provided in the apparatus main body 3 (they are not shown). An opening (not shown) is formed in the enclosure part 53C along the front-and-rear direction. The magnet roller 51 is exposed through the opening.
Next, the front end part 53F of the housing 53 will be described with reference to
As shown in
The holder portion 71 is formed in a rectangular plate-like shape when viewed from the inserting/drawing direction (the front-and-rear direction). The holder portion 71 has a mounting surface along a surface orthogonal to the inserting/drawing direction (a vertical surface). The relay board B is supported on the mounting surface with a vertical posture. The terminal pins (not shown) of the relay board B project rearward from the holder portion 71.
The lever portion 75 has a main body 77 and a hook 79. The main body 77 is formed in an L-shape when viewed from the left-and-right direction, and has a horizontal portion 77a and a vertical portion 77b. The horizontal portion 77a has a rectangular box-like shape when viewed from the upper-and-lower direction, whose upper surface is opened, and has a predetermined thickness along the upper-and-lower direction. In the open space of the horizontal portion 77a, a plurality of ribs is formed along the front-and-rear direction. The vertical portion 77b is formed so as to extend downward from the rear end portion of the horizontal portion 77a, has a rectangular box-like shape when viewed from the inserting/drawing direction (the front-and-rear direction), whose rear surface is opened, and has a predetermined thickness in the front-and-rear direction. In the open space of the vertical portion 77b, a plurality of ribs 78 (see
The lower ends of the elastic arm portions 73 are connected to the upper end portion of the holder portion 71, and the upper ends of the elastic arm portions 73 are connected to the vertical portion 77b of the main body 77 of the lever portion 75 on both sides of the hook 79. The elastic arm portions 73 are inclined obliquely upward and backward from the lower end toward the upper end. When the elastic arm portions 73 are elastically deformed, the lever portion 75 is y movable in the upper-and-lower direction with respect to the holder portion 71. At this time, the hook 79 moves in the upper-and-lower direction behind the holder portion 71.
The outer cover plate 61 and the inner cover plate 63 are disposed on the front side and the rear side of the holder member 65, and are connected to each other.
The outer cover plate 61 has a lower portion 81 in which the holder portion 71 of the holder member 65 is stored and an upper portion 83 in which the lever portion 75 of the holder member 65 is stored.
The lower portion 81 has a rectangular box-like shape when viewed in the inserting/drawing direction (the front-and-rear direction), whose rear surface is opened, and has a rectangular front wall, an upper wall, a lower wall, a left wall and a right wall which are provided around the outer periphery of the front wall. The upper wall is formed longer rearward than the other walls. In the upper wall, two grooves 85 (see
The upper portion 83 has a substantially pentagonal box-like shape when viewed from the inserting/drawing direction (the front-and-rear direction), whose rear surface and lower surface are opened, and has a substantially pentagonal front wall, an upper wall, a left wall and a right wall which are provided around the outer periphery of the front wall. The front wall has a protruding portion 87 horizontally protruding forward. The protruding portion 87 has a rectangular box-like shape when viewed in the upper-and-lower direction, whose lower surface is opened, and has a rectangular upper wall and a peripheral wall around the outer periphery of the upper wall. As shown in
The upper portion 83 is integrally formed with the rear end portion of the upper wall of the lower portion 81. A space is formed between the protruding portion 87 of the upper portion 83 and the lower portion 81 in the upper-and-lower direction.
The inner cover plate 63 has a substantially pentagonal box-like shape when viewed in the inserting/drawing direction (the front-and-rear direction), whose rear surface is opened, and has a substantially pentagonal front wall, which is the same shape as the upper portion 83 of the outer cover plate 61, and an outer peripheral wall around the outer periphery of the front wall. On the rear surface of the front wall, bearing portions to which the front end portions of the rotating shafts of the rollers are supported in a rotatable manner are formed.
The inner cover plate 63 is connected to the upper portion 83 of the outer cover plate 61 in a posture in which the rib 91 of the outer cover plate 61 and the front wall of the inner cover plate 63 are parallel to each other. The holder portion 71 of the holder member 65 is stored in the lower portion 81 of the outer cover plate 61 in an unmovable manner. At this time, the terminal pins of the relay board B supported by the holder portion 71 project rearward from the lower portion 81.
The lever portion 75 of the holder member 65 is supported between the upper portion 83 of the outer cover plate 61 and the inner cover plate 63. The horizontal portion 77a of the main body 77 is stored in the protruding portion 87 of the outer cover plate 61 through the opening 89 of the front wall of the upper portion 83. As shown in
An attachment operation of the development device 39 having the above configuration to the apparatus main body 3 will be described with reference to
As shown in
As shown in
As shown in
In the rear attachment part, the roller driving part is connected to the driving source, the toner replenishing part is communicated with the replenishing port of the toner container 25, and the waste toner collection portion is communicated with the communication port of the waste toner collection container. Further, the magnet roller 51 exposed from the opening of the enclosure part 53C faces the photosensitive drum 35.
When the development device 39 is detached from the apparatus main body 3, the horizontal portion 77a of the main body 77 of the holder member 65 and the protruding portion 87 of the outer cover plate 61 are held by fingers from the upper side and the lower side. Then, the horizontal portion 77a of the main body 77 of the holder member 65 is pushed up toward the protruding portion 87, the pair of elastic arm portions 73 is elastically deformed, and the lever portion 75 of the holder member 65 moves upward relative to the holder portion 71. At this time, the horizontal portion 77a of the main body 77 of the lever portion 75 moves upward in the space of the protruding portion 87 of the outer cover plate 61, and the vertical portion 77b moves upward between the ribs 91 of the outer cover plate 61 and the front wall of the inner cover plate 63. As a result, the hook 79 is separated upward from the recess 3a (see
As described above, according to the present disclosure, since the hook 79 is engaged with the recess 3a in a snap-fit manner by the pair of elastic arm portions 73, the holder member 65 can be formed by one component. Thus, the assembly of the development device 39 can be made simple.
Further, because the lever portion 75 (the vertical portion 77b of the main body 77) of the holder member 65 is guided by both cover plates 61 and 63 (the ribs 91 of the outer cover plate 61 and the front wall of the inner cover plate 63) in the upper-and-lower direction, the hook 79 can be stably engaged with the recess 3a in a snap-fit manner.
Next, with reference to
Since the pair of elastic arm portions 73 of the holder member 65 is elastically deformed when the development device 39 is attached and detached, if the attachment and detachment operation is repeated, the pair of elastic arm portions 73 may be damaged. In this case, the coil spring 97 is housed in the recess 95. The coil spring 97 is disposed between the bottom surface of the recess 95 and the bottom surface of the space of the protruding portion 87 of the outer cover plate 61. If the pair of elastic arm portions 73 are broken, and the holder portion 71 and the lever portion 75 of the holder member 65 are separated from each other, the lever portion 75 is allowed to be moved in the upper-and-lower direction with respect to the holder portion 71 by elastic deformation of the coil spring 97.
That is, at the attachment of the development device 39, when the hook 79 of the lever portion 75 is pushed up by the front wall of the recess 3a of the apparatus main body 3 as described above, the coil spring 97 is compressed and the lever portion 75 moves upward relative to the holder portion 71. When the hook 79 reaches the recess 3a, the lever portion 75 is biased downward by the coil spring 97 so that the hook 79 is engaged with the recess 3a. At the detachment of the development device 39, when the horizontal portion 77a of the main body 77 of the holder member 65 and the protruding portion 87 of the outer cover plate 61 are held with the fingers from the upper side and the lower side, the lever portion 75 of the holder member 65 moves upward relative to the holder portion 71 against the biasing force of the coil spring 97, and the hook 79 is separated upward from the recess 3a. Thereafter, the development device 39 is drawn out forward while the lever portion 75 moved upward with respect to the holder part 71.
As described above, even when the pair of elastic arm portions 73 is damaged, the development device 39 can be repeatedly used by attaching the coil spring 97.
Although one aspect of the embodiment according to the present disclosure is described, the present disclosure is not limited to the above embodiment. The present disclosure may be modified, substituted, or modified in various ways without departing from the spirit of the technical idea.
Number | Date | Country | Kind |
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2020-165053 | Sep 2020 | JP | national |