Image forming device

Abstract

The present invention relates to an image forming device that improves the convenience of installation operation of the loading and unloading unit relative to the loaded and unloaded part while maintaining high positioning stability of the loading and unloading unit relative to the loaded and unloaded part. The image forming device is provided with a developing device in the loading and unloading unit that can be loaded and unloaded relative to the loaded and unloaded part. The developing device develops a latent image on a latent image carrier arranged on one side of the loaded and unloaded part by using a developer carried on a developer carrier. The image forming device includes: a pressurizing component that pressurizes the loading and unloading unit to generate a force that applies the developer carrier toward the latent image carrier side. The loaded and unloaded part has a main reference part that abuts and positions the main reference part of the loading and unloading unit, and an auxiliary reference part that abuts and blocks the rotation of the loading and unloading unit around the main reference part. The pressure of the pressurizing component generates a rotational torque around the main reference part toward the auxiliary reference part relative to the loading and unloading unit.

Description

Technical Field

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

[0002] Conventionally, a known image forming apparatus has a developing device disposed on a detachable unit detachable from a detachable portion, and develops a latent image on a latent image bearing member disposed on the detachable portion side with a developer carried on a developer bearing member.

[0003] For example, the image forming device disclosed in Patent Document 1 is an image forming unit that is freely attachable and detachable to the main body of the image forming device, and includes a drum unit (mounted and detached portion) having a photosensitive body (latent image carrier) and a developing unit (attachment and detachment unit) that is freely attachable and detachable to the drum unit. A cylindrical protrusion (main reference portion) and a U-shaped groove (auxiliary reference portion) for positioning the developing unit are formed on the drum unit, and a U-shaped groove (main reference portion) and a protrusion (auxiliary reference portion) corresponding to the two grooves are formed on the developing unit. The U-shapes of the two grooves are formed in the same direction, and the developing unit is installed in the drum unit in such a way that the two protrusions enter along the U-shapes of the two grooves. Thus, the developing unit is positioned in the main body of the image forming device via the drum unit.

[0004] In addition, in the drum unit, a force-applying member (pressure-applying member) for applying pressure to the developing unit in order to generate a force for applying the developing roller (developer carrier) of the developing unit toward the photosensitive body is provided on a holder rotatably mounted relative to the drum unit. Before the developing unit is mounted, the holder is rotated so that the force-applying member is retracted from the groove of the drum unit, and after the developing unit is mounted, the holder is rotated and locked. As a result, the force-applying member applies a protrusion of the developing unit toward the inner side of the groove of the drum unit, generating a force for applying the developing roller toward the photosensitive body.

[0005] However, in conventional image forming apparatuses, although the positioning stability of the detachable unit relative to the detachable portion is high, there is a problem that the installation operation of the detachable unit relative to the detachable portion is complicated and the convenience is poor.

[0006] [Patent Document 1] (Japanese) Patent Publication No. 2010-170010 Summary of the invention

[0007] In order to solve the above-mentioned problem, the present invention relates to an image forming device in which a developing device is arranged in a loading and unloading unit that can be loaded and unloaded relative to a loaded and unloaded part, and the developing device develops a latent image on a latent image carrier arranged on one side of the loaded and unloaded part by carrying a developer on a developer carrier. The image forming device includes: a pressure-applying component, which pressurizes the loading and unloading unit to generate a force that applies the developer carrier toward the latent image carrier side, the loaded and unloaded part has a main reference part that abuts and positions the main reference part of the loading and unloading unit, and an auxiliary reference part that abuts and blocks the rotation of the loading and unloading unit around the main reference part, and the pressure of the pressure-applying component generates a rotational torque around the main reference part toward the side of the auxiliary reference part relative to the loading and unloading unit.

[0008] According to the present invention, it is possible to improve the convenience of the installation operation of the detachable unit with respect to the detachable portion while maintaining high positioning stability of the detachable unit with respect to the detachable portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 FIG. 1 is a diagram schematically showing the structure of an example of an image forming apparatus according to an embodiment of the present invention.

[0010] Figure 2 FIG. 1 is a schematic diagram showing the structure of a process unit in which a developing unit in the image forming apparatus is detachably mounted.

[0011] Figure 3 The figure shows a schematic diagram of the structure of the developing unit which is detachably installed in the processing unit.

[0012] Figure 4 The figure is an explanatory diagram of the state where the developing unit is inserted into the process unit.

[0013] Figure 5 Shown is an explanatory diagram of a state in which the developing unit is inserted deep into the process unit.

[0014] Figure 6 FIG. 1 is an explanatory diagram showing a state in which the developing unit is being rotated and mounted on the process unit.

[0015] Figure 7 Shown is an explanatory diagram of a state in which the developing unit is mounted on the process unit. DETAILED DESCRIPTION

[0016] Hereinafter, the present invention will be described with respect to one embodiment applied to a monochrome image forming apparatus 10 of an electrophotographic system as an image forming apparatus.

[0017] First, the basic structure of the image forming apparatus will be described.

[0018] Figure 1 FIG. 1 is a diagram schematically showing a configuration of an example of an image forming apparatus 100 according to the present embodiment.

[0019] like Figure 1 As shown, the image forming apparatus 100 is a black-and-white image forming apparatus. In the apparatus main body (image forming apparatus main body), a process unit 1 as an image forming unit is detachably mounted.

[0020] The processing unit 1 includes a photoreceptor 2 as a latent image carrier that carries an image on its surface, a charging roller 3 as a charging mechanism that charges the surface of the photoreceptor 2, and a cleaning blade 5 as a cleaning mechanism that cleans the surface of the photoreceptor 2. In addition, in the processing unit 1, an LED headlight array 6 as an exposure mechanism that exposes the surface of the photoreceptor 2 is provided at a position facing the photoreceptor 2. In addition, a developing unit 4 is detachably mounted in the processing unit 1, and the developing unit 4 has a developing device as a developing mechanism that visualizes the latent image on the photoreceptor 2. In this embodiment, the processing unit 1 is a detachable portion, and the developing unit 4 is a detachable unit.

[0021] In the apparatus body of the image forming apparatus 100 of the present embodiment, a toner cartridge 7 as a toner container, i.e., a developer container, is detachably provided. The toner cartridge 7 has a developer container 8 as a toner container in its container body 22 for containing developer, i.e., toner supplied to the developing unit 4, and a developer recovery section 9 as a waste toner container for recovering toner removed by the cleaning blade 5 (waste toner).

[0022] In addition, the image forming apparatus 100 has a transfer device 10 for transferring an image onto a paper as a recording material, a paper supply device 11 for supplying paper, a fixing device 12 for fixing the image transferred onto the paper, and a paper discharge device 13 for discharging the paper to the outside of the apparatus.

[0023] The transfer device 10 includes a transfer roller 14 as a transfer member. The transfer roller 14 abuts against the photoreceptor 2 and forms a transfer nip at the abutment portion of the two. The transfer roller 14 is connected to a power source and a predetermined direct current voltage (DC) and / or alternating current voltage (AC) is applied thereto.

[0024] The paper feeding device 11 includes a paper feeding cassette 15 for storing paper P and a paper feeding roller 16 for feeding the paper P stored in the paper feeding cassette 15. In addition, a registration roller pair 17 is provided on the downstream side of the paper feeding direction relative to the paper feeding roller 16, which calculates the feeding timing to feed the paper toward the transfer nip portion and serves as a timing roller. In addition, the paper P includes thick paper, postcards, envelopes, ordinary paper, thin paper, coated paper (coated paper or coated paper, etc.), tracing paper, etc. In addition, as a recording medium other than paper, OHP sheets, OHP films, cloth, etc. can also be used.

[0025] The fixing device 12 has a fixing roller 18 as a fixing member and a pressure roller 19 as a pressure member. The fixing roller 18 is heated by a heating source such as a heater. The pressure roller 19 is pressed toward the fixing roller 18 so as to contact the fixing roller 18, and a fixing nip is formed at the contacting portion.

[0026] The paper discharge device 13 includes a pair of paper discharge rollers 20. The paper discharged to the outside of the device by the paper discharge rollers 20 is stacked on a paper discharge tray 21 formed concavely on the upper surface of the device body.

[0027] Next, an image forming operation of the image forming apparatus 100 according to the present embodiment will be described.

[0028] When the imaging operation starts, the photoreceptor 2 is driven to rotate, and the surface of the photoreceptor 2 is uniformly charged to a predetermined polarity by the charging roller 3. Then, based on the image information from the reading device or computer, etc., an electrostatic latent image is formed on the charged surface of the photoreceptor 2 by exposure of the LED headlight array 6. In the electrostatic latent image thus formed on the photoreceptor 2, the electrostatic latent image is visualized (visible) as a toner image by the toner supplied by the developing roller 41 as a developer carrier of the developing unit 4.

[0029] When the image forming operation starts, the paper feed roller 16 starts to rotate and drive, and the paper P is fed out from the paper feed cassette 15. The fed paper P is temporarily stopped by the registration roller pair 17. Thereafter, the registration roller pair 17 starts to rotate and drive at a predetermined timing, and the paper P is fed toward the transfer nip according to the timing when the toner image on the photosensitive body 2 reaches the transfer nip.

[0030] At this time, a transfer voltage having a polarity opposite to that of the toner charge of the toner image on the photoreceptor 2 is applied to the transfer roller 14, thereby forming a transfer electric field in the transfer section. Then, the toner image on the photoreceptor 2 is transferred to the paper P by the transfer electric field. The residual toner on the photoreceptor 2 that has not been completely transferred to the paper P is removed by the cleaning blade 5 and recovered in the developer recovery section 9 in the toner cartridge 7.

[0031] The paper P with the toner image transferred thereto is conveyed toward the fixing device 12, and is heated and pressed when passing through the fixing nip between the fixing roller 18 and the pressure roller 19, thereby fixing the toner image on the paper P. Then, the paper P is discharged to the outside of the device by the paper discharge roller 20 and is stacked on the paper discharge tray 21.

[0032] Next, a configuration for attaching and detaching the developing unit 4 in this embodiment to and from the apparatus main body will be described.

[0033] Figure 2 FIG. 1 is a schematic diagram showing the structure of a process unit 1 to which a developing unit 4 is detachably mounted.

[0034] Figure 3 FIG. 1 is a schematic diagram showing the structure of a developing unit 4 that is detachably installed in the processing unit 1 .

[0035] The frame of the processing unit 1 in this embodiment is provided with guide rails 31 and 32 at both end surfaces (side surfaces) in the axial direction of the photosensitive body 2 for guiding the guided portion of the developing unit 4 when the developing unit 4 is attached or detached. The guided portion of the developing unit 4 in this embodiment is a main reference shaft 42 as a main reference portion for positioning the developing unit 4 relative to the processing unit 1. A part of the guide rails 31 and 32 of the processing unit 1 abuts against the main reference shaft 42 on one side of the developing unit 4, thereby constituting main reference surfaces 31a and 32a, which are main reference portions for positioning the developing unit 4 at the target position of the processing unit 1.

[0036] In order to stably position the developing unit 4, an auxiliary reference member 43 forming an auxiliary reference surface 34a is provided in the process unit 1. In addition, a pressurizing member 33 for pressurizing the developing unit 4 is provided in the process unit 1 to generate a force for urging the developing roller 41 of the developing unit 4 toward the photosensitive body 2 side of the process unit 1. The pressurizing member 33 presses the pressed portion 44 of the developing unit 4 by the force of the spring 33a through the pressurizing portion 33b, thereby generating a force for urging the developing roller 41 toward the photosensitive body 2 side.

[0037] A driven gear 41a is provided on the rotation axis of the developing roller 41 provided in the developing unit 4, and is engaged with the driving gear 2a on the rotation axis of the photosensitive body 2 provided in the processing unit 1. When the developing unit 4 is positioned relative to the processing unit 1, the driving gear 2a is engaged with the driven gear 41a, and the developing roller 41 is driven to rotate as the photosensitive body 2 is driven to rotate.

[0038] In addition, the main reference shaft 42 is coaxially arranged with the rotation axis of the developing roller 41 provided in the developing unit 4. The main reference shaft 42 is provided so as to protrude axially outward from the roller end of the developing roller 41. In addition, an auxiliary reference member 43 as an auxiliary reference portion that abuts against the auxiliary reference surface 34a of the processing unit 1 is provided in the frame of the developing unit 4. In addition, a pressurized portion 44 that abuts against the pressurizing portion 33b of the pressurizing member 33 of the processing unit 1 and receives the pressurizing force is provided in the frame of the developing unit 4. In addition, a handle portion 45 for the operator to hold when performing the mounting and dismounting operation of the developing unit 4 on the processing unit 1 is also provided in the frame of the developing unit 4.

[0039] Next, refer to Figure 4 to Figure 7 , a method for installing the developing unit 4 to the processing unit 1 is described.

[0040] When installing the developing unit 4 into the processing unit 1, the operator first holds the handle 45 of the developing unit 4 and moves along the top of the processing unit 1. Figure 4 The developer unit 4 is inserted into the process unit 1 in the direction indicated by the arrow A in FIG. At this time, the operator inserts the side ( Figure 4 The developing unit 4 is inserted into the processing unit 1 by placing the main reference shaft 42 on the end surface (in the front-to-rear direction) of the developing unit 4 onto the lower guide rail 31 and sliding the main reference shaft 42 along the lower guide rail 31.

[0041] like Figure 4 As shown in the figure, since the lower guide rail 31 of the processing unit 1 is inclined downward in the insertion direction, even if the operator does not push the developing unit 4 in the insertion direction, the developing unit 4 can be slid by the weight of the developing unit 4. Since the main reference shaft 42 in this embodiment is a cylindrical member, no matter where the circumference of the main reference shaft 42 contacts the lower guide rail 31, it is actually a point contact, the contact area is small, and therefore the friction force is small, so that a smooth sliding action (insertion action) can be performed.

[0042] like Figure 5 As shown in the figure, when the developing unit 4 is inserted deeply relative to the processing unit 1, the developing roller 41 of the developing unit 4 is in a state (in use state) of contact with the photosensitive body 2 of the processing unit 1. In addition, at this time, the driven gear 41a provided on the rotating shaft of the developing roller 41 of the developing unit 4 is meshed with the driving gear 2a provided on the rotating shaft of the photosensitive body 2 of the processing unit 1.

[0043] In addition, when the developing unit 4 is inserted into the processing unit 1 and the developing roller 41 is in contact with the photosensitive body 2, the developing unit 4 cannot be further inserted. As a result, the main reference shaft 42 of the developing unit 4 is inserted to the specified position of the guide rails 31 and 32 of the processing unit 1. At this specified position, the main reference shaft 42 is embedded with a certain gap between a portion 31a of the lower guide rail 31 and a portion 32a of the upper guide rail 32. As a result, the positioning of the developing unit 4 relative to the main reference of the processing unit 1 is completed. That is, the portion 31a of the lower guide rail 31 and the portion 32a of the upper guide rail 32 into which the main reference shaft 42 is embedded become the main reference surface in this embodiment.

[0044] Thus, in the present embodiment, a portion of the guide rails 31 and 32 constitutes the main reference surfaces 31a and 32a. Therefore, the main reference shaft 42 sliding on the lower guide rail 31 slides to the position (predetermined position) of the main reference surfaces 31a and 32a and reaches the main reference surfaces 31a and 32a, thereby completing the positioning of the developing unit 4 relative to the main reference of the processing unit 1.

[0045] If the main reference surface is located at a different position from the guide rail, in order to make the main reference axis (which can be the same as or different from the guided part guided by the guide rail) contact (place) with the main reference surface, it is necessary to move the guided part away from the guide rail (lift it). This is because, if the guided part is not moved away from the guide rail, the main reference cannot be positioned by the contact between the main reference surface and the main reference axis. In this case, two stages of operation are required, such as the operation of sliding the guided part relative to the guide rail and the operation of moving the guided part away from the guide rail, which will impair the convenience of the operator.

[0046] On the other hand, according to the present embodiment, the positioning of the developing unit 4 relative to the main reference of the process unit 1 is completed only by inserting the developing unit 4 into the process unit 1. Therefore, the convenience for the operator is high.

[0047] After the main reference is positioned as described above, Figure 5 As shown, the operator moves the developing unit 4 to the direction of the main reference axis 42. Figure 5 The developing unit 4 rotates in the direction indicated by the arrow B. At this time, the rotation torque generated by its own weight acts in the developing unit 4 in the direction indicated by the arrow B. Figure 5 Therefore, the operator only needs to weaken the force of the handle portion 45 supporting the developing unit 4 from below.

[0048] When the developing unit 4 rotates around the main reference axis 42 in this manner, Figure 6As shown, the pressed portion 44 of the developing unit 4 contacts the upper surface 33b1 of the pressing portion 33b of the pressing member 33 of the processing unit 1. The upper surface 33b1 of the pressing portion 33b of the present embodiment is as shown in FIG. Figure 6 As shown in the figure, the inclined surface is formed, and a part of the force of the spring 33a of the pressure member 33 is used as a force to resist the force of the pressure portion 33b pressed down by the dead weight of the developing unit 4. Therefore, in this embodiment, the dead weight of the developing unit 4 alone cannot overcome the force of the spring 33a to push the pressure portion 33b of the pressure member 33, and the pressed portion 44 of the developing unit 4 is placed on the upper surface 33b1 of the pressure portion 33b.

[0049] When the operator Figure 6 When the handle 45 of the downward developing unit 4 is operated from this state as shown by the arrow C in FIG. 1 , the pressing portion 33b of the pressing member 33 can be moved to the lower side by overcoming the force of the spring 33a. Figure 6 As a result, the pressed portion 44 of the developing unit 4 can pass over the pressing portion 33b, so that the developing unit 4 is opened in the direction indicated by the arrow F in FIG. Figure 6 Further rotation in the direction of arrow B.

[0050] When the developing unit 4 is thus Figure 6 When the direction of arrow B is further rotated, Figure 7 As shown, the auxiliary reference member 43 of the developing unit 4 abuts against the auxiliary reference surface 34a of the processing unit 1. As a result, the rotation of the developing unit 4 around the main reference axis 42 is prevented by the auxiliary reference surface 34a, and as a result, the positioning of the developing unit 4 relative to the auxiliary reference of the processing unit 1 is completed. As a result, the position of the developing unit 4 relative to the main reference axis 42, which is the rotation axis of the processing unit 1, is positioned by the main reference surfaces 31a, 32a, and the rotation position relative to the processing unit 1 is positioned by the auxiliary reference surface 34a. As a result, the position of the developing unit 4 relative to the processing unit 1 is determined.

[0051] At this time, since the auxiliary reference member 43 of the developing unit 4 abutting against the auxiliary reference surface 34a of the process unit 1 is a spherical surface or a curved surface, the auxiliary reference member 43 can substantially point-contact with the auxiliary reference surface 34a and abut against it without looseness.

[0052] When the auxiliary reference member 43 of the developing unit 4 is in contact with the auxiliary reference surface 34a of the processing unit 1, the pressed portion 44 of the developing unit 4 is in the state of being pressed against the auxiliary reference surface 34a of the processing unit 1. Figure 7 As shown in FIG. 1 , the lower surface 33b2 of the pressurizing portion 33b is in contact with the lower surface 33b2 of the pressurizing portion 33b. Figure 7 The inclined surface is shown in FIG. 1 , and a part of the force of the spring 33a of the pressing member 33 is used to push the pressed portion 44 of the developing unit 4 toward the Figure 7 The force is applied in the direction indicated by the arrow D.

[0053] In this way, the developing unit 4 is pressurized by the pressurizing member 33, and the developing roller 41 of the developing unit 4 generates a force that applies force toward the photosensitive body 2. Therefore, even if some external force (impact, etc.) is applied to cause the developing roller 41 to move away from the photosensitive body 2, the movement of the developing roller 41 in the direction away from the photosensitive body 2 can be prevented by the pressurizing force of the pressurizing member 33 (the force of the spring 33a). That is, the movement of the main reference shaft 42 of the developing unit 4 in the removal direction (the direction opposite to the insertion direction) along the guide rail 3132 is prevented. Therefore, the positioning of the main reference of the developing unit 4 relative to the processing unit 1 is stably maintained.

[0054] In particular, the auxiliary reference surface 34a in this embodiment is substantially parallel to the main reference surfaces 31a and 32a. Thus, the slidable directions of the developing unit 4 are unified, and the unevenness of the force of the developing roller 41 toward the photosensitive body 2 due to the pressure of the pressure member 33 is reduced.

[0055] Furthermore, when some external force (impact, etc.) is applied, a force may be applied in a direction that causes the auxiliary reference member 43 of the developing unit 4 to move away from the auxiliary reference surface 34a of the processing unit 1. In this case, the position of the developing unit 4 relative to the processing unit 1 (auxiliary reference position) may be deviated.

[0056] In this embodiment, if Figure 7 As shown, when viewed from the axial direction of the developing roller 41 (the axial direction of the main reference axis 42), the direction D of the pressure force of the pressure member 33 is more downward than the straight line E connecting the main reference axis 42, the pressure member 33 and the abutment portion of the auxiliary reference axis 43. That is, the pressure force of the pressure member 33 has a force component that generates a rotation torque about the main reference axis 42 of the auxiliary reference element 43 of the developing unit 4 toward the auxiliary reference surface 34a of the processing unit 1. Therefore, a part of the pressure force of the pressure member 33 becomes a restraining force that prevents the auxiliary reference element 43 of the developing unit 4 from moving in a direction away from the auxiliary reference surface 34a of the processing unit 1. Therefore, the positioning of the developing unit 4 relative to the auxiliary reference of the processing unit 1 is also stably maintained.

[0057] Thus, it is also possible to omit an additional fixing member for preventing the developing unit 4 from rotating in the direction in which the auxiliary reference member 43 moves away from the auxiliary reference surface 34a. If such an additional fixing member can be omitted, not only the structure can be simplified, but also the operator can omit the operation of operating the additional fixing member, further improving convenience.

[0058] In addition, the angle formed by the direction D of the applied force and the straight line E is preferably within a range of 10° to 30°. When the angle is less than 10°, the force pressing the auxiliary reference member 43 against the auxiliary reference surface 34a is insufficient, and the positioning of the developing unit 4 relative to the auxiliary reference of the processing unit 1 may be unstable. In addition, when the angle is greater than 30°, when the operator removes the developing unit 4 from the processing unit 1, the force required to pull the handle 45 upward becomes large, which may deteriorate the convenience.

[0059] In addition, in the present embodiment, the pressing force of the pressing member 33 is set so that the force component parallel to the auxiliary reference surface 34a is larger than the force component generating the rotation torque around the main reference axis 42. Specifically, the inclination angle of the lower surface 33b2 of the pressing portion 33b of the pressing member 33 and the shape of the pressed portion 44 of the developing unit 4 are determined in such a manner as to generate such a pressing force. By configuring such a pressing force to be generated, the friction between the auxiliary reference member 43 and the auxiliary reference surface 34a can be reduced, and sufficient force for applying the developing roller 41 of the developing unit 4 toward the photosensitive body 2 side can be ensured. As a result, the positioning of the main reference of the developing unit 4 relative to the process unit 1 can be further stabilized.

[0060] In addition, in the present embodiment, as described above, the driven gear 41a provided on the rotating shaft of the developing roller 41 meshes with the driving gear 2a provided on the rotating shaft of the photosensitive body 2, and the developing roller 41 is driven by the photosensitive body 2. At this time, the direction of the pressure angle of the driven gear 41a is in the direction in which the driven gear 41a is separated from the driving gear 2a. Therefore, in order to maintain appropriate meshing even when the developing roller 41 is driven from the photosensitive body 2, it is required to prevent the driven gear 41a from being displaced in the direction away from the driving gear 2a.

[0061] The pressing force of the pressing member 33 may be set to prevent the driven gear 41a from being displaced away from the driving gear 2a. In this case, the force for stably maintaining the positioning of the developing unit 4 relative to the main reference and the auxiliary reference of the process unit 1 may be weakened.

[0062] When the developing roller 41 is driven from the photosensitive body 2, if the driven gear 41a is displaced in the direction away from the driving gear 2a, the developing unit 4 will be displaced in that direction along with the displacement. However, in the structure of this embodiment, the direction of the pressure angle of the driven gear 41a is approximately perpendicular to the main reference surface 31a (for example, 90°±5°). Therefore, even if the main reference axis 42 of the developing unit 4 is displaced in this direction, it will be blocked by the main reference surface 31a of the lower guide rail 31 of the processing unit 1, and the developing unit 4 cannot move in this direction. Therefore, when the developing roller 41 is driven from the photosensitive body 2, the displacement of the driven gear 41a in the direction away from the driving gear 2a is blocked, and the proper meshing of the driven gear 41a and the driving gear 2a is maintained.

[0063] In the present embodiment, the detachable part is the process unit 1, but it may be the image forming apparatus main body. In addition, the developing unit 4 as a detachable unit may include devices or components other than the developing device.

[0064] The above description is just an example, and the following various methods all have unique effects.

[0065] [First method]

[0066] The first mode relates to an image forming device (100) in which a developing device is arranged in a detachable unit (e.g., a developing unit 4) that can be detached from a detachable portion (e.g., a processing unit 1), wherein the developing device develops a latent image on a latent image bearing body (e.g., a photosensitive body 22) arranged on one side of the detachable portion by using a developer carried on a developer bearing body (e.g., a developing roller 41), and the image forming device includes: a pressurizing component (33) that pressurizes the detachable unit to cause the developer bearing body to be pressed toward the latent image bearing body The force applied from the body side is such that the loaded and unloaded part has a main reference part (e.g., main reference surfaces 31a, 32a) abutting and positioning against a main reference part (e.g., main reference axis 42) of the loading and unloading unit, and an auxiliary reference part (e.g., auxiliary reference surface 34a) abutting against an auxiliary reference part (e.g., auxiliary reference part 43) of the loading and unloading unit and blocking the rotation of the loading and unloading unit around the main reference part. The pressure applied by the pressure component generates a rotational torque around the main reference part toward the auxiliary reference part relative to the loading and unloading unit.

[0067] In the conventional image forming apparatus, the pressing force of the pressing member that presses the attachment and detachment unit in order to generate the force for urging the developer carrier toward the latent image carrier also serves as a restraining force that prevents the attachment and detachment unit from moving in a direction away from the attachment and detachment portion. Therefore, the attachment and detachment unit is less likely to shift in position due to the pressing force of the pressing member, and the positioning stability of the attachment and detachment unit relative to the attachment and detachment portion is high.

[0068] However, in conventional image forming apparatuses, the main reference and auxiliary reference for positioning the detachable unit relative to the detachable unit are both formed by inserting the protrusion into the U-shaped groove. Therefore, when installing the detachable unit to the detachable unit, the operator must insert the protrusion into the main reference groove and the auxiliary reference groove at the same time. This operation is complicated and inconvenient for the operator because it requires inserting the protrusion into both grooves at the same time.

[0069] In contrast, in the present method, when the loading and unloading unit is installed on the loaded and unloaded part, first, the main reference part is brought into contact with the main reference part to position the loading and unloading unit relative to the main reference of the loaded and unloaded part. Then, after the main reference is positioned, the loading and unloading unit is rotated around the main reference part, and the auxiliary reference part of the loading and unloading unit is brought into contact with the auxiliary reference part of the loaded and unloaded part to position the auxiliary reference. In this way, if the auxiliary reference is positioned after the main reference is positioned, the auxiliary reference positioning operation does not need to be performed during the main reference positioning operation, and in addition, the main reference positioning operation does not need to be performed during the auxiliary reference positioning operation. As a result, the operation becomes very simple and convenient for the operator.

[0070] Furthermore, in this method, in order to generate the force for applying the developer carrier to the latent image carrier, a rotation torque about the main reference portion toward the auxiliary reference portion is generated relative to the detachable unit by applying pressure to the detachable unit by the pressurizing member for applying pressure to the detachable unit. Therefore, a part of the pressurizing force of the pressurizing member becomes a restraining force for preventing the auxiliary reference portion of the detachable unit from moving in the direction away from the auxiliary reference portion of the detachable unit. Therefore, the stability of the positioning of the detachable unit relative to the detachable unit is also high.

[0071] [Second method]

[0072] The second aspect is that in the first aspect, the developer bearing member has a driven gear 41 a on its rotation shaft to mesh with the driving gear 2 a disposed on the rotation shaft of the latent image bearing member.

[0073] Thus, even when the pressure angle of the driven gear is directed away from the driving gear, the driven gear can be prevented from being away from the driving gear due to the pressing force of the pressing member. Thus, appropriate meshing between the driven gear and the driving gear is maintained.

[0074] [Third Method]

[0075] A third aspect is the second aspect, wherein the direction of the pressure angle of the driven gear is substantially perpendicular to the surface of the main reference portion.

[0076] Thus, the driven gear can be prevented from moving away from the driving gear by the surface of the main reference portion. Thus, the pressure of the pressure member that serves as a restraining force to prevent the auxiliary reference portion of the loading and unloading unit from moving in the direction away from the auxiliary reference portion of the loaded and unloaded portion is not weakened, and the proper meshing of the driven gear and the driving gear is maintained.

[0077] [Fourth Method]

[0078] A fourth aspect is any one of the first to third aspects, wherein the detachable portion includes guide rails 31 and 32 for guiding the main reference portion during attachment and detachment of the detachable unit, and a portion of the guide rails constitutes the main reference portion.

[0079] Thus, since the positioning of the main reference of the detachable unit with respect to the detachable portion is completed only by performing the operation of moving the detachable unit along the guide rail, the convenience for the operator is further improved.

[0080] [Fifth Method]

[0081] A fifth aspect is any one of the first to fourth aspects, wherein a surface of the auxiliary reference portion is substantially parallel to a main reference surface constituting a surface of the main reference portion.

[0082] Thus, the slidable directions of the attaching and detaching units are unified, and the unevenness of the force of the developer bearing member being urged toward the latent image bearing member by the pressing force of the pressing member is reduced.

[0083] [Sixth Method]

[0084] A sixth aspect is any one of the first to fifth aspects, wherein a force component parallel to the surface of the auxiliary reference portion during the pressurization by the pressurizing member is larger than a force component generating the rotational torque.

[0085] This can reduce the frictional force between the auxiliary reference portion and the auxiliary reference part, thereby ensuring a sufficient force for urging the developer bearing member of the mounting and removal unit toward the latent image bearing member.

[0086] [Seventh method]

[0087] The seventh method is that in any one of the first to sixth methods, the pressing direction of the pressing component is within the range of 10° to 30° relative to the line connecting the rotation axis of the latent image carrier and the rotation axis of the developer carrier when viewed from the rotation axis direction of the latent image carrier.

[0088] If the angle is less than 10°, the force pressing the auxiliary reference part against the auxiliary reference part will be insufficient, and the positioning of the loading and unloading unit relative to the auxiliary reference of the loaded and unloaded part may be unstable. In addition, if the angle is greater than 30°, the force required when the operator removes the loading and unloading unit from the loaded and unloaded part will increase, which may deteriorate the convenience.

[0089] [Eighth Method]

[0090] An eighth aspect is any one of the first to seventh aspects, wherein the auxiliary reference portion is a curved surface.

[0091] Thus, the auxiliary reference portion can be brought into substantial point contact with the auxiliary reference portion, and can abut against the auxiliary reference portion without any looseness, thereby improving the stability of positioning of the detachable unit with respect to the detachable portion.

Claims

1. An image forming device having a developing device disposed in a detachable unit that can be attached to and detached from a detachable portion, the developing device developing a latent image on a latent image bearing member disposed on one side of the detachable portion with a developer carried on a developer bearing member, the image forming device comprising: a pressurizing member that pressurizes the attachment and detachment unit to generate a force that urges the developer carrier toward the latent image carrier, The loaded and unloaded part has a main reference part that abuts against and positions the main reference part of the loading and unloading unit, and an auxiliary reference part that abuts against an auxiliary reference part of the loading and unloading unit and blocks the rotation of the loading and unloading unit around the main reference part. The pressurization of the pressurizing member generates a rotation torque about the main reference portion toward the auxiliary reference portion with respect to the detachable unit. The force component of the pressurization by the pressurizing member that is parallel to the surface of the auxiliary reference portion is larger than the force component that generates the rotational torque.

2. The image forming device according to claim 1, wherein: The developer bearing member has a driven gear on its rotation shaft to mesh with a driving gear disposed on the rotation shaft of the latent image bearing member.

3. The image forming apparatus according to claim 2, wherein: The direction of the pressure angle of the driven gear is perpendicular to the surface of the main reference portion.

4. The image forming apparatus according to any one of claims 1 to 3, characterized in that: The detachable portion includes a guide rail for guiding the main reference portion during attachment and detachment of the detachable unit, and a portion of the guide rail constitutes the main reference portion.

5. The image forming apparatus according to any one of claims 1 to 3, characterized in that: The surface of the auxiliary reference portion is parallel to the surface of the main reference portion.

6. The image forming apparatus according to any one of claims 1 to 3, characterized in that: The pressing direction of the pressing member is within a range of 10° to 30° with respect to a line connecting the rotation axis of the latent image bearing body and the rotation axis of the developer bearing body when viewed from the rotation axis direction of the latent image bearing body.

7. The image forming apparatus according to any one of claims 1 to 3, characterized in that: The auxiliary reference part is a curved surface.

Images