Image forming apparatus

Abstract

This prevents deterioration in the feel of opening and closing the door. [Solution] The image forming apparatus comprises a first arm member having a first engaging portion that engages with the rotating body of a damper unit for shock absorption with an opening / closing unit, and a second arm member having a second engaging portion that engages with the rotating body and is movably mounted relative to the first arm member. The first engaging portion of the first arm member and the second engaging portion of the second arm member are made to overlap in the direction of movement of the arm members so that the second arm smoothly engages with the rotating body.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] In recent years, for the purpose of improving the quality of image forming apparatuses, various proposals have been made to improve the operability of parts that users operate. Among them, in a so-called door part where a part of the exterior opens and closes for trouble shooting such as when a jam occurs, there is a means for alleviating the impact generated at the moment when the door is opened to a predetermined opening position and stopped by a stopper member or the like. This not only provides a comfortable operation feeling for the user, but also avoids damage to the image forming apparatus main body and the door itself due to the impact when opening.

[0003] As means for alleviating the impact caused by the opening and closing operation of such a door, specifically, the following proposals have been made.

[0004] Patent Document 1 discloses an image forming apparatus in which a plurality of opening angles are set for one door. As examples of the plurality of opening angles, mainly an opening angle for trouble shooting performed by the user and an opening angle for replacement of parts or units to be regularly replaced, represented by a so-called service technician, are set.

[0005] That is, the main trouble shooting performed by the user includes the operation of removing jammed paper or other residual paper when a jam occurs. In that case, it is sufficient to open the door by an amount sufficient to remove the jammed paper. When a service technician replaces parts or units to be regularly replaced, in order to perform the work smoothly and without damaging the replacement items, the door is switched to open wider than when dealing with a jam.

[0006] The image forming apparatus also has a door impact mitigation means comprising a damper unit having a damper that applies a rotational load to a rotating body, and an arm portion that engages with the rotating body. The arm portion engages with the rotating body (pinion) to apply a rotational load of the damper to the door, which acts as an opening and closing unit. The arm portion comprises a first arm member and a second arm member provided to be movable relative to the first arm member, and extends and retracts in conjunction with the opening and closing operation of the door. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2016-78271 [Overview of the project] [Problems that the invention aims to solve]

[0008] The deflection of the first arm is maximized when only the last tooth engages with the rotating body (pinion). If the rotational load on the rotating body is increased, the deflection of the first arm will increase proportionally. As a result, it becomes more difficult for the second arm to engage with the rotating body, the smooth extension and retraction of the arm section does not occur, and the feel of operation deteriorates.

[0009] Therefore, the objective of the present invention is to ensure that the second arm smoothly engages with the rotating pair without degrading operability. [Means for solving the problem]

[0010] The present invention relates to an image forming apparatus comprising: an opening / closing unit provided to a main body so as to be openable and closable; and an impact mitigation means for mitigating impact on the opening / closing unit, wherein the impact mitigation means comprises: a damper unit having a rotating body and a damper that applies a rotational load to the rotating body; and an arm portion that engages with the rotating body and moves in conjunction with the operation of the opening / closing unit, wherein the arm portion engages with the rotating body to apply a rotational load of the damper to the opening / closing unit, wherein the arm portion comprises: a first arm member having a first engaging portion that engages with the rotating body; and a second arm member having a second engaging portion that engages with the rotating body and being provided so as to be movable relative to the first arm member, wherein the arm portion extends and retracts in conjunction with the opening and closing operation of the opening / closing unit, and the first arm member and the first engaging portion and the second arm member and the second engaging portion overlap in the direction of movement of the second arm member. [Effects of the Invention]

[0011] According to the present invention, it is possible to avoid degrading operability. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic cross-sectional view of an image forming apparatus equipped with an opening / closing unit. [Figure 2] A schematic diagram of an image forming apparatus equipped with an opening and closing unit. [Figure 3] A schematic diagram of an image forming apparatus equipped with an opening and closing unit. [Figure 4] A schematic diagram showing the meshing of a pinion with a rotary damper and a rack. [Figure 5] A schematic diagram showing the configuration that maintains the meshing between the pinion and the rack. [Figure 6] A schematic diagram illustrating the configuration of a rack with a gear section. [Figure 7] A schematic diagram showing the door in a closed position. [Figure 8] A schematic diagram showing the door opened to its first opening position. [Figure 9]Schematic diagram showing the state where the door is opened to the second opening position. [Figure 10] Schematic diagram showing the overlap of the fixed gear and the slide gear.

Embodiments for Carrying Out the Invention

[0013] [Example 1] An image forming apparatus according to a preferred embodiment of the present invention will be described in detail by way of example while referring to the drawings. Note that the dimensions, materials, relative positions, etc. of the component parts of the image forming apparatus described below are not intended to limit the scope of the present invention only to those, unless otherwise specifically described.

[0014] First, an image forming apparatus having an opening / closing unit according to the present embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic cross-sectional view showing the schematic configuration of an image forming apparatus having an opening / closing unit according to the present embodiment.

[0015] As shown in FIG. 1, the image forming apparatus 100 forms an image on a sheet sent by a feeding device 103 housed inside a main body 101 by an image forming unit 102.

[0016] The image forming unit 102 is composed of a drum unit 5, a developing unit 6, an intermediate transfer belt unit 9, etc. The drum unit 5 has a photosensitive drum 4 on which an electrostatic latent image is formed by an exposure device 1 that irradiates light based on image data. The developing unit 6 develops the electrostatic latent image by supplying toner sent from a toner bottle 10 to the photosensitive drum 4. The intermediate transfer belt unit 9 transfers the toner image formed on the photosensitive drum 4. The drum unit 5, the developing unit 6, and the intermediate transfer belt unit 9 are each configured to be detachable from the main body 101 for jam processing inside the main body 101, maintenance, and replacement of internal mechanisms.

[0017] The sheet fed from the feeding device 103 passes through the image forming unit 102, the door unit 104, and the fixing device 11 that permanently fixes the toner transferred to the sheet. Then, the sheet is discharged onto the discharge tray 8 outside the main body 101.

[0018] The drum unit 5, the developing unit 6, the toner bottle 10, and the paper feed cassette 7 inside the image forming unit 102 are inserted and removed from the front side of the main body 101. On the other hand, the fixing device 11 and the intermediate transfer belt unit 9 inside the image forming unit 102 are inserted and removed by opening the door unit 104 on the side surface of the main body 101. Also, the operation of removing the sheet when a jam occurs is mainly performed by opening the door unit 104. Note that the front of the image forming apparatus refers to the apparatus surface when viewing the image forming apparatus shown in FIG. 1 from the front side of the apparatus. The side surface means that when viewing the image forming apparatus shown in FIG. 1 from the front, the right side is the right side surface and the left side is the left side surface.

[0019] Also, the door unit 104 is provided so as to be openable and closable with respect to the main body 101, and is an opening and closing unit having a plurality of opening positions with different opening angles. The door unit 104 is provided on one side surface of the main body 101 (here, the right side surface where the sheet conveyance path is provided). The door unit 104 is pivotally supported by a shaft 12 disposed at the lower part of the main body 101 and is provided so as to be rotatable about the shaft 12. Further, the door unit 104 is provided with a gripping portion 13 so that an operator can open and close it. When performing jam processing or maintenance of the internal mechanism, etc., the operator moves the door unit 104 to the right with respect to the main body 101 by holding the gripping portion 13 and rotates it around the shaft 12, so that the inside of the main body is exposed and accessible.

[0020] FIG. 2 and FIG. 3 are schematic views of the image forming apparatus 100 when the door unit 104 with a cross-section of the vicinity where the damper mechanism is arranged inside the main body is opened.

[0021] The door unit 104 is provided with a rack 40, which serves as an arm portion that constitutes an impact mitigation means to reduce the impact when the door unit 104 is opened. The rack 40 provided on the door unit 104 moves in conjunction with the rotation of the door unit 104 around the axis 12. At that time, the rack 40 moves while meshing with the pinion 23 (see Figure 4), thereby providing a damping function. The pinion 23 with the rotary damper 22 is located inside a damper unit 105 that is positioned in the main frame 14, which is a component of the main body 101.

[0022] Furthermore, Figures 4 and 5 specifically illustrate the configuration of the damper unit 105. Figures 4 and 5 are perspective views showing the damper unit 105 located inside the main body and a portion of the rack 40 that engages with the pinion 23 of the damper unit 105.

[0023] As shown in Figures 4 and 5, the damper unit 105, together with the rack 40, constitutes an impact mitigation means that reduces the impact at at least one opening position of the opening / closing unit, which has multiple opening positions with different opening angles. The damper unit 105 consists of a rotary damper 22 to which a pinion 23, which is a rotating body having a gear portion on its outer circumference, is attached, and a damper holder 24 for attaching them to the main frame 14.

[0024] The damper holder 24 is equipped with a rack disengagement prevention member 25 and a rack thrust slippage prevention member 26 to stabilize the meshing between the pinion 23 and the gear portion 41 of the rack 40. These prevent the rack 40 from moving in the rotational axis direction of the pinion 23 and disengaging the gear portion 41 of the pinion 23 and the rack 40.

[0025] The rack in an image forming apparatus will be explained in detail using Figures 7 and 8.

[0026] As shown in Figures 7 and 8, the rack 40 consists of a fixed part (first arm member) 40a fixed to the door unit 104 and a sliding part (second arm member) 40b attached to the fixed part 40a so as to be slidable within a specific range in the arc direction. As the sliding part 40b moves relative to the fixed part 40a, the amount of protrusion of the sliding part 40b from the fixed part 40a changes, causing the rack 40 to expand and contract.

[0027] A fixed gear 41a is provided on a part of the fixed portion 40a, which serves as a first engaging portion that meshes with the pinion 23. A slide gear 41b is also provided on a part of the slide portion 40b, which serves as a second engaging portion that meshes with the pinion 23. In other words, the gear portion 41 of the rack 40, which serves as an engaging portion that meshes with the pinion 23, consists of a fixed gear 41a provided on a part of the fixed portion 40a and a slide gear 41b provided on a part of the slide portion 40b.

[0028] Furthermore, the final tooth of the stationary gear 41a and the initial teeth of the slide gear 41b overlap in the direction of movement of the slide gear 41b (see Figure 10). In Figure 10, the overlap portion between the stationary gear 41a and the slide gear 41b is indicated by 42. In this embodiment, when the slide portion 40b is closest to the base of the stationary portion 40a (when the rack 40 is most retracted), the teeth of the stationary gear 41a and the teeth of the slide gear 41b overlap in the direction in which the rack 40 extends. Here, it is preferable that the width (engagement width) of the pinion 23 in the direction along the rotation axis is configured to be greater than or equal to the sum of the engagement width of the stationary gear 41a and the engagement width of the slide gear 41b.

[0029] The fixed gear 41a engages with the pinion 23 from a point slightly before the first opening position at angle α shown in Figure 2, when the door unit 104 is closed as shown in Figure 7. The gears are positioned to engage up to the point where the door unit 104 is opened to the first opening position at angle α. Figure 8 shows the door unit 104 in the open position at angle α. In other words, in this embodiment of the image forming apparatus, the fixed gear 41a is set to engage with the pinion 23 within a predetermined range corresponding to the first opening position. Here, the opening angle α of the first opening position is assumed to be 45° (not a particularly limiting value), and this is the opening angle at which the door unit 104 is opened mainly when the user performs jamming. The fixed gear 41a and the pinion 23 are set to engage from approximately 20° before this angle α. Furthermore, the damper function of the damper unit 105 mitigates the impact when the door unit 104 is opened to angle α and stopped at the first opening position by a stopper function (not shown). One of the purposes of mitigating impact is to provide users with a more comfortable experience during operation. Another purpose is to prevent damage to the door itself, or deformation of the main body components, especially the main body frame 14, caused by the impact when the user releases their hand while opening the door or opens it with a force exceeding the expected load.

[0030] Furthermore, the fixed gear 41a and pinion 23 are designed not to engage when the door unit 104 is nearly closed. This is to avoid adding to the user's opening operation and also for ease of operation. When the door unit 104 is just beginning to open, the weight of the door itself has almost no effect on the opening direction. Therefore, if the fixed gear 41a and pinion 23 were engaged when the door unit 104 was just beginning to open, the rotational load of the rotary damper 22 would become dominant, directly adding to the user's opening operation. To avoid this, the fixed gear 41a and pinion 23 are designed not to engage when the door unit 104 is nearly closed. Moreover, if there is a rotational load on the damper when the door is slightly open, the door unit 104 may stop even if it is not in the predetermined opening position when the user releases their hand. This could pose a problem in terms of ease of operation, and this design also aims to avoid that.

[0031] As shown in Figure 7, the slide gear 41b is positioned to be continuously connected to the fixed gear 41a when the rack 40 is in its most retracted state. The final tooth of the fixed gear 41a and the initial teeth of the slide gear 41b overlap in the direction of movement of the slide gear 41b, as shown in Figure 10. In other words, the final tooth of the fixed gear 41a and the initial teeth of the slide gear 41b overlap when viewed along the rotation axis of the pinion 23. In this embodiment of the image forming apparatus, the slide gear 41b has 4 teeth (this is not a particularly limited value). When the door unit 104 is opened further by releasing a stopper function (not shown) for maintenance, the slide gear 41b now meshes with the pinion 23. As a result, the rotational load of the rotary damper 22 prevents the pinion 23 from rotating, and the movement of the slide part 40b is restricted. Then, the fixed part 40a, which has a fixed gear 41a that is disengaged from the pinion 23, slides circumferentially relative to the sliding part 40b whose movement is restricted. As a result, the rack 40 extends as shown in Figure 9. Figure 9 shows the door unit 104 opened to a second opening position at an angle β, which is larger than the opening angle α. The amount of slide of the fixed part 40a relative to the sliding part 40b is appropriate to the extent that the engagement between the slide gear 41b and the pinion 23 is maintained when the door unit 104 shown in Figure 2 is opened from angle α to angle β shown in Figure 3. In the image forming apparatus of this embodiment, the opening angle β at the second opening position is 75° (this is not a particularly limiting value). Since the fixed gear 41a has an engagement range of approximately 50°, the remaining 25° + [margin] is the amount of slide of the fixed part 40a relative to the sliding part 40b.

[0032] Furthermore, as mentioned above, the final tooth of the fixed gear 41a and the initial teeth of the slide gear 41b overlap in the direction of movement of the rack 40. The purpose of this overlap is to address the following issues.

[0033] If the last tooth of the stationary gear 41a and the first tooth of the slide gear 41b do not overlap, the following problems arise. Specifically, when the last tooth of the stationary gear 41a engages with the pinion 23, the rotational load of the rotary damper 22 causes the deflection of the stationary part 40a to be maximum. This deflection increases in proportion to the magnitude of the load on the rotary damper. Due to the deflection of the stationary part 40a, the last tooth of the stationary gear 41a disengages from the teeth of the pinion 23 before the first tooth of the adjacent slide gear 41b engages with the pinion 23. As a result, the door unit 104 is opened and closed with the slide gear 41b not engaged with the pinion 23. In addition, because the rack 40 and the pinion 23 are not aligned, the rotational load of the rotary damper 22, which is a shock absorption means, does not act on the door unit 104.

[0034] In contrast, when the last tooth of the stationary gear 41a and the first tooth of the slide gear 41b overlap, the following occurs: When the last tooth of the stationary gear 41a engages with the pinion 23, the first tooth of the slide gear 41b also engages with the pinion 23. Therefore, the pinion 23 and the slide gear 41b engage stably. Furthermore, the rotational load of the rotary damper 22, which is an impact mitigation means, can always be applied to the door unit 104.

[0035] In the configuration of the image forming apparatus described so far, the rotary damper may be of a type where the rotational load is applied in both directions of rotation. In this case, the operation from opening the door unit 104 to angle β to closing it will return from Figure 9 to Figure 8 and Figure 7. Therefore, a detailed explanation of the operation sequence will be omitted here.

[0036] According to this embodiment, when the slide gear 41b and the pinion 23 engage, the fixed gear 41a of the fixed part 40a and the slide gear 41b of the slide part 40b overlap. Therefore, the switching from the fixed gear 41a of the fixed part 41a to the slide gear 41b of the slide part 40b can be made smooth, and the rotational load of the rotary damper 22 can be increased without worsening operability.

[0037] In this embodiment, the rack 40 is attached to the door unit 104, and the damper unit 105, which includes a pinion 23 that meshes with the rack 40, is attached to the main frame 14. However, the embodiment is not limited to this. For example, if the basic configuration of the rack 40 and the damper unit 105 are similar, the damper unit 105 may be attached to the door unit 104, and the rack 40 may be attached to the main frame 14. In this case, the damper unit 105 moves together with the door unit 104 as the door unit 104 operates. In the direction of movement of the damper unit 105, the final tooth of the fixed gear 41a and the initial teeth of the slide gear 41b overlap.

[0038] Furthermore, in the embodiments described above, a gear portion that meshes with the pinion was given as an example of the engaging portion of the arm portion, but it is not limited to this. For example, the rotating body may be a rubber roller, and an arc-shaped engaging portion that presses against and engages with the outer surface of the rubber roller may be provided on the arm portion.

[0039] Furthermore, in the embodiments described above, an example was illustrated in which the present invention is applied to the impact mitigation means of a door unit that opens an opening for attaching and detaching an intermediate transfer belt unit. However, the invention is not limited to this. Similar effects can be obtained by applying the present invention to the impact mitigation means of an opening / closing unit that opens an opening for attaching and detaching other units such as a feed cassette, drum unit, and developing unit.

[0040] Furthermore, in the embodiments described above, a printer was used as an example of an image forming apparatus. However, the present invention is not limited thereto. For example, other image forming apparatuses such as photocopiers and facsimile machines, or other image forming apparatuses such as multifunction devices that combine these functions, may also be used. Moreover, the present invention is not limited to image forming apparatuses that use an intermediate transfer body. An image forming apparatus that uses a recording material carrier and sequentially overlays and transfers toner images of each color onto the recording material carried on the recording material carrier may also be used. An image forming apparatus equipped with an inkjet-type image forming unit may also be used. Similar effects can be obtained by applying the present invention to the shock-absorbing means of the opening / closing unit that opens the opening for attaching and detaching the unit in these image forming apparatuses. [Explanation of symbols]

[0041] 5 Drum Units 6. Developing Unit 7 Feeding Cassette 9. Intermediate transfer belt unit 10 toner bottles 11. Fuser 12 axes 13 Gripping part 14 Main frame 22 Rotary damper 23 pinion 24 Damper Holder 40 racks 40a Fixed part 40b Slide section 42 Overlap section 100 Image forming apparatus 101 Main Unit 102 Image forming unit 103 Feeding device 104 Door Unit 105 Damper Unit

Claims

1. An image forming apparatus comprising an opening / closing unit provided to the main body so as to be openable and closable, and an impact mitigation means for mitigating the impact on the opening / closing unit, The aforementioned impact mitigation means is A damper unit having a rotating body and a damper that applies a rotational load to the rotating body, It comprises an arm portion that engages with the rotating body and moves in conjunction with the operation of the opening and closing unit, The arm portion engages with the rotating body, thereby applying a rotational load of the damper to the opening / closing unit. The aforementioned arm portion is A first arm member having a first engaging portion that engages with the rotating body, A second arm member is provided movably with respect to the first arm member and has a second engaging portion that engages with the rotating body, It extends and retracts in conjunction with the opening and closing operation of the aforementioned opening and closing unit. An image forming apparatus characterized in that the first arm member and the first engagement portion and the second engagement portion of the second arm member overlap in the direction of movement of the second arm member.

2. The image forming apparatus according to claim 1, characterized in that, as the opening and closing unit is opened, the first engaging portion and the rotating body engage, thereby mitigating the impact on the opening and closing unit by the rotational load of the damper, the second engaging portion and the rotating body engage, and the engagement between the first engaging portion and the rotating body is released, causing the first arm member having the first engaging portion to move relative to the second arm member having the second engaging portion, thereby extending the arm portion.

3. The image forming apparatus according to claim 2, characterized in that the damper applies a load to at least the rotation of the rotating body in the direction of opening the opening / closing unit.

4. The rotating body is a pinion having a gear portion on its outer circumference, The image forming apparatus according to claim 1, characterized in that the first engaging portion and the second engaging portion are gear portions that mesh with the pinion.

5. The image forming apparatus according to claim 1, characterized in that the engagement width of the rotating body is greater than or equal to the sum of the engagement width of the first arm member and the engagement width of the second arm member.

6. An image forming apparatus comprising an opening / closing unit provided to the main body so as to be openable and closable, and an impact mitigation means for mitigating the impact on the opening / closing unit, The aforementioned impact mitigation means is The arm section, The damper unit comprises a rotating body that engages with the arm portion and a damper that applies a rotational load to the rotating body, and moves in conjunction with the operation of the opening and closing unit. The arm portion engages with the rotating body, thereby applying a rotational load of the damper to the opening / closing unit. The aforementioned arm portion is A first arm member having a first engaging portion that engages with the rotating body, A second arm member is provided movably with respect to the first arm member and has a second engaging portion that engages with the rotating body, It extends and retracts in conjunction with the opening and closing operation of the aforementioned opening and closing unit. An image forming apparatus characterized in that the first engaging portion of the first arm member and the second engaging portion of the second arm member overlap during the movement of the second arm member.

Images