Developing device and method for stirring initial developer in developing device

Abstract

To manually cancel a tapping state of a developing device in a state where the developing device is mounted in an image forming apparatus.SOLUTION: An image forming apparatus comprises: an image carrier; a developing device having a developer carrier, a first chamber, a second chamber, a first communication unit, a second communication unit, a first conveying screw, a second conveying screw, a pair of sealing members that seal the first communication unit and the second communication unit for storing initial developer in the second chamber, and a drive input member that receives input of a driving force for rotating the second conveying screw; a driving source for supplying the driving force to the drive input member; and a mounting part for mounting the developing device. The drive input member is provided with an operating unit for externally receiving a force for manually rotating the second conveying screw in a state where the developing device is mounted on the mounting part.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus including a developing device that develops an electrostatic image formed on an image carrier with a developer containing toner and carrier. [Background technology]

[0002] In the developing device described in Patent Document 1, a developer supply opening provided in a developer storage section is sealed with a sealing member, and a rotatable take-up shaft for taking up the sealing member is connected to a developer stirring member via a drive train in the developing device. In addition, in the configuration of Patent Document 1, before using the developing device, it is possible to manually remove the sealing member by directly turning the take-up shaft with a tool while moving the gear at the end of the take-up shaft away from the drive train in the developing device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-40054 A Summary of the Invention [Problem to be solved by the invention]

[0004] Depending on the transport and storage conditions of the developing device before the sealing member is opened (at the time of shipment), the developer in the sealed developer storage chamber may be in a compressed state (tapping state) downstream of the transport direction of the transport / agitation screw even before the use of the developing device. If the developing device is initially started up (initialization operation of the development drive) while in a tapping state, the load torque of the motor for rotating the screw that transports and agitates the developer increases. If the load torque of the motor exceeds a certain value, there is a risk of a screw lock, which makes it impossible to rotate the screw.

[0005] In order to eliminate the tapping state of the developing device attached to the image forming apparatus, an operator must once remove the developing device from the image forming apparatus before starting up the developing device, shake the developing device to dissolve the developer, and then reattach the developing device to the image forming apparatus. Therefore, a new configuration is desired that allows an operator to eliminate the tapping state of the developing device even when the developing device is still attached to the image forming apparatus.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus that allows the developer to manually release the tapping state of the developer device when the developer device is attached to the image forming apparatus. [Means for solving the problem]

[0007] In order to achieve the above object, an image forming apparatus according to one aspect of the present invention includes the following configuration: an image carrier, a developer carrier that carries a developer containing toner and a carrier for developing an electrostatic image formed on the image carrier, a first chamber for supplying developer to the developer carrier, a second chamber that is partitioned from the first chamber by a partition wall and in which developer circulates between the first chamber and the second chamber, a first communication portion that allows developer to communicate from the second chamber to the first chamber, a second communication portion that allows developer to communicate from the first chamber to the second chamber, a first conveying screw that is disposed in the first chamber and conveys developer in a first direction from the first communication portion toward the second communication portion, and a second conveying screw that is disposed in the second chamber and conveys developer from the second communication portion to the first chamber. The developing device includes a second conveying screw that conveys developer in a second direction toward the first communicating portion, a pair of sealing members that seal each of the first communicating portion and the second communicating portion to accommodate initial developer in the second chamber, and a drive input member to which a drive force for rotating the second conveying screw is input, a drive source that supplies drive force to the drive input member, and a mounting portion for mounting the developing device, wherein the drive input member is provided with an operating portion for receiving a force from the outside to manually rotate the second conveying screw when the developing device is mounted in the mounting portion. Effect of the Invention

[0008] According to the present invention, the tapping state of the developing device can be manually released when the developing device is attached to the image forming apparatus. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration of an image forming apparatus. [Diagram 2] FIG. 2 is a diagram illustrating a cross-sectional configuration of a developing device. [Diagram 3] FIG. 2 is a cross-sectional view for illustrating a planar configuration of the developing device. [Figure 4] 2A to 2C are diagrams for explaining a planar configuration of a developing device and an operation of the developing device; [Diagram 5] 5 is a cross-sectional view illustrating a sealing structure for an initial developer in the developing device. FIG. [Figure 6] 3A and 3B are diagrams illustrating a configuration of a drive gear train of the developing device. [Figure 7] 5A and 5B are diagrams for explaining the operation of a drive mechanism of the developing device. [Figure 8] 5 is a perspective view for explaining the operation of a drive mechanism of the developing device. FIG. [Figure 9] 5A to 5C are diagrams illustrating the unwinding operation of the developing device according to the first embodiment. [Figure 10] 5A to 5C are diagrams for explaining an unwinding operation of the developing device according to the first embodiment (in a state in which the developing device is attached to an image forming apparatus). [Figure 11] FIG. 4 is a diagram for explaining an unlocking operation from outside the main body of the image forming apparatus according to the first embodiment. [Figure 12] FIG. 2 is a diagram illustrating a cross-sectional configuration of the developing device according to the first embodiment in a pressurized state. [Figure 13] FIG. 2 is a diagram illustrating a cross-sectional configuration of the developing device in a separated state according to the first embodiment. [Figure 14] FIG. 2 is a diagram for explaining the configuration of the small door in a closed state according to the first embodiment. [Figure 15] FIG. 2 is a diagram for explaining the configuration of the small door in an open state according to the first embodiment. [Figure 16] 5A to 5C are diagrams for explaining prevention of erroneous operation by a detachable member according to the first embodiment. [Figure 17] 13 is a diagram for explaining the configuration of the small door in an open state according to the second embodiment. FIG. [Figure 18] 13A to 13C are diagrams illustrating the unwinding operation of the developing device according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the present invention, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the present invention. The present invention can be implemented in various applications, such as printers, various printing machines, copiers, FAX machines, and multifunction machines.

[0011] [First embodiment] <Configuration of Image Forming Apparatus> Fig. 1 is an explanatory diagram of the configuration of an image forming apparatus 200. As shown in Fig. 1, the image forming apparatus 200 is a full-color printer of a tandem type intermediate transfer system in which yellow, magenta, cyan, and black image forming units Sa, Sb, Sc, and Sd are interchangeably mounted and arranged along an intermediate transfer belt 7.

[0012] In the image forming station Sa, a yellow toner image is formed on the photosensitive drum 1a (image carrier) and then transferred to the intermediate transfer belt 7. In the image forming station Sb, a magenta toner image is formed on the photosensitive drum 1b and then transferred to the intermediate transfer belt 7. In the image forming stations Sc and Sd, a cyan toner image and a black toner image are formed on the photosensitive drums 1c and 1d, respectively, and then transferred to the intermediate transfer belt 7.

[0013] The intermediate transfer belt 7 is stretched over primary transfer rollers 5a, 5b, 5c, and 5d, an opposing roller 8, a tension roller 17, and a tension roller 18, and is driven by the opposing roller 8, which also serves as a drive roller, to rotate in the direction of arrow R7. The four-color toner image transferred onto the intermediate transfer belt 7 is transported to a secondary transfer section T2, and secondarily transferred onto a recording material P taken out of a recording material cassette 10 and transported to the secondary transfer section T2. ​​The recording material P is supplied to the secondary transfer section T2 by a feeding and transporting device having a paper feed roller, a transport roller, a registration roller, etc. (none of which are shown).

[0014] The recording material P onto which the toner image has been transferred at the secondary transfer section T2 is heated and pressurized in a fixing device 13 having a pressure roller 15 pressed against a fixing roller 14, and the toner image is fixed onto the surface thereof, after which the recording material P is discharged outside the machine body.

[0015] The image forming units Sa, Sb, Sc, and Sd are configured almost identically, except that the colors of toner used in the developing devices 100a, 100b, 100c, and 100d are different. In the following, the image forming unit Sa will be described, and the image forming units Sb, Sc, and Sd will be described by replacing the suffix a attached to the components of the image forming unit Sa with b, c, and d.

[0016] The image forming section Sa has a charging roller 2a, an exposure device 3a, a developing device 100a, a primary transfer roller 5a, and an auxiliary charging roller 6a arranged around a photosensitive drum 1a.

[0017] The photosensitive drum 1a is an aluminum cylinder having a photosensitive layer with a negative charge polarity formed on the outer peripheral surface thereof, and rotates in the direction of the arrow R1 at a predetermined process speed. The charging roller 2a charges the surface of the photosensitive drum 1a to a uniform negative potential. The exposure device 3a scans a laser beam with a rotating mirror to write an electrostatic image of an image on the charged surface of the photosensitive drum 1a. The developing device 100a develops the electrostatic image formed on the photosensitive drum 1a using a two-component developer consisting of toner and carrier, forming a toner image on the photosensitive drum 1a.

[0018] The primary transfer roller 5a presses against the inner surface of the intermediate transfer belt 7 to form a primary transfer portion T1 between the photosensitive drum 1a and the intermediate transfer belt 7. By applying a positive DC voltage to the primary transfer roller 5a, the negative toner image carried on the photosensitive drum 1a is primarily transferred to the intermediate transfer belt 7. The auxiliary charging roller 6a charges the transfer residual toner that has escaped transfer to the recording material P and remains on the photosensitive drum 1a to a negative polarity, and causes the toner to participate in the next development by the developing device 100a.

[0019] A belt cleaner 11 is in contact with the intermediate transfer belt 7 at a position corresponding to the tension roller 17 in order to remove residual toner adhering to the intermediate transfer belt 7 .

[0020] <Configuration of the developing device> Fig. 2 is an explanatory diagram of the cross-sectional configuration of the developing device. Fig. 3 is an explanatory diagram of the planar configuration of the developing device. In the following, the developing devices mounted in an exchangeable manner in the image forming unit will be described by omitting the suffixes a, b, c, and d that distinguish the image forming unit. The developing device 100 can be attached to a mounting portion for mounting the developing device.

[0021] 2, the developing device 100 develops an electrostatic image (latent image) on the photosensitive drum 1 by carrying a developer containing toner and carrier on a developing sleeve 102, which is an example of a developer carrier. The developing sleeve 102 is rotatably arranged in an opening of a developing container 101 that faces the photosensitive drum 1. A layer thickness regulating blade 121 is arranged upstream in the rotation direction of a development area where the developing sleeve 102 and the photosensitive drum 1 face each other, and regulates the thickness of the developer carried by the developing sleeve 102.

[0022] The inside of the developing container 101 is divided into a developing chamber 101a and a stirring chamber 101b by a vertically provided partition wall 103. The developing chamber 101a and the stirring chamber 101b (circulation path) contain a two-component developer, which is a mixture of non-magnetic toner, magnetic carrier, and a small amount of external additive.

[0023] A magnet 102m is disposed inside the developing sleeve 102, with multiple magnetic poles arranged on its surface and supported non-rotatably. The developer is carried on the surface of the developing sleeve 102 by magnetic carriers bound by magnetic flux formed between the magnetic poles of the magnet 102m, and a magnetic brush is formed by negatively charged toner being electrostatically bound to the surface of the positively charged carrier. The power source 52 applies an oscillating voltage in which an AC voltage is superimposed on a negative DC voltage, and transfers the negatively charged toner carried by the magnetic brush to the electrostatic image on the photosensitive drum 1.

[0024] 3, the developing container 101 is divided into two parallel spaces by a partition wall 103. The stirring chamber 101b and the developing chamber 101a are configured to be capable of containing and transporting a two-component developer. The developing device 100 includes the stirring chamber 101b having a stirring screw 104b (second transport member) therein, the developing chamber 101a having a developing screw 104a (first transport member) therein, and a developing sleeve 102 disposed near the upper portion of the developing chamber 101a.

[0025] The openings 107a and 107b formed at both ends of the partition wall 103 allow the stirring chamber 101b and the developing chamber 101a to communicate with each other, forming a circulation path for the developer. The developer is transferred from the stirring chamber 101b (second chamber) to the developing chamber 101a (first chamber) through the opening 107a (first communication portion). On the other hand, the developer is transferred from the developing chamber 101a (first chamber) to the stirring chamber 101b (second chamber) through the opening 107b (second communication portion). That is, the opening 107a (first communication portion) allows the developer to communicate from the stirring chamber 101b (second chamber) to the developing chamber 101a (first chamber). Also, the opening 107b (second communication portion) allows the developer to communicate from the developing chamber 101a (first chamber) to the stirring chamber 101b (second chamber).

[0026] As the developer circulates through the circulation path configured in this manner while being stirred, friction occurs between the toner particles and carrier particles, causing the toner to be negatively charged and the carrier to be positively charged. The developer is transported downstream while being stirred by the stirring screw 104b inside the stirring chamber 101b, and then passes through the opening 107a without the partition wall 103 and flows into the developing chamber 101a. The developer is then carried by the developing sleeve 102 inside the developing chamber 101a while being transported downstream by the developing screw 104a.

[0027] A developing screw 104a, which is an example of a first conveying screw, is rotatably attached inside the developing chamber 101a, which is an example of a first chamber. When the developing screw 104a rotates, the two-component developer is conveyed from the upstream side to the downstream side of the developing chamber 101a, as shown by the arrow B.

[0028] A mixing screw 104b, which is an example of a second conveying screw, is rotatably attached inside the mixing chamber 101b, which is an example of a second chamber. When the mixing screw 104b rotates, the two-component developer is conveyed from the upstream side to the downstream side of the mixing chamber 101b, as shown by the arrow A.

[0029] A toner supply mechanism 105 is disposed above the upstream side of the mixing chamber 101b. The toner contained in a toner bottle (not shown) is transported to the toner supply mechanism 105 through a toner transport path (not shown), and passes through a toner supply port 106 to drop and be supplied into the mixing chamber 101b. In the developing device 100, the same type of toner as the initial developer is used as the replenishment toner.

[0030] Here, the toner charge amount Q / M of the two-component developer is an important parameter that determines the density of the developed image. There is a correlation between the weight ratio of the toner contained in the two-component developer (toner concentration T / D) and the toner charge amount Q / M.

[0031] Since the toner is charged by the friction of contact with the carrier, the more the toner comes into contact with the carrier, the larger the toner charge amount Q / M becomes. Therefore, in a two-component developer, the smaller the toner concentration T / D is, the larger the toner charge amount Q / M becomes, and the image density when the same electrostatic image is developed decreases. For this reason, the toner concentration T / D of the developer circulating in the development chamber 101a and the mixing chamber 101b is constantly detected by the magnetic permeability sensor T. Then, the amount of toner replenished from the toner replenishment mechanism 105 is adjusted so that the toner concentration T / D is kept approximately constant.

[0032] <Initial developer sealing structure> Fig. 4 is an explanatory diagram of the plan configuration of the developing device as viewed from above. Fig. 5 is an explanatory diagram of the sealing structure of the initial developer in the developing device. Fig. 5 is a vertical cross section as viewed from the EE direction in Fig. 4.

[0033] As shown in FIG. 4, the relationship between the developing device 100, the driving motor 53, the power source 52, the control unit 50, the operation panel 56, and the load detection means 58 of the driving motor 53 is shown using a block diagram. In addition, in the developing device 100, a sealing sheet 51a, which is an example of a sealing member, is attached to the opening 107a of the partition wall 103 that separates the developing container 101, and a sealing sheet 51b, which is an example of a sealing member, is attached to the opening 107b. With this configuration, in the developing device 100 at the time of shipment, the initial developer is filled in a sealed state only in the stirring chamber 101b, and at this time, neither the carrier nor the toner is present in the developer inside the developing chamber 101a. That is, the sealing sheet 51a and the sealing sheet 51b serve as a pair of sealing members that seal the opening 107a (first communicating portion) and the opening 107b (second communicating portion) to accommodate the initial developer in the stirring chamber 101b.

[0034] 5, a sealing sheet 51a, which is an example of a sealing member, is a sheet member attached to the opening 107a in a peelable (openable) manner. The sealing sheet 51a is attached to the opening 107a on the downstream side in the conveying direction of the second conveying screw.

[0035] The sealing sheet 51a is folded upward from the lower end while sealing the opening 107a, and the tip is fixed to the winding shaft 600. Similarly, the opening 107b on the opposite side is folded upward from the lower end while sealing the opening 107b, and the tip is fixed to the common winding shaft 600.

[0036] The winding shaft 600, which is a sealing sheet opening mechanism, is connected to the developing sleeve 102 so as to be capable of transmitting rotation through a gear train, so that as the developing sleeve 102 rotates, the sealing sheets 51a, 51b are wound around the winding shaft 600, thereby opening the openings 107a, 107b. The winding shaft 600 automatically peels off the sealing sheets 51a, 51b of the developing device 100 from the openings 107a, 107b without relying on the user's operation. Then, the developer is circulated and distributed inside the developing chamber 101a and the stirring chamber 101b, thereby setting up the developing device 100 to a usable state (initialization operation of the developing device is completed).

[0037] <Seal release drive mechanism> FIG. 6 is an explanatory diagram of the drive gear train of the developing device 100, where (a) and (b) are perspective views showing the same part from different directions. As shown in FIG. 6 with reference to FIG. 4, the developing device 100 has a developing screw 104a connected to a drive motor 53 installed on the main body (apparatus main body) side of the image forming apparatus 200 via a coupling 54 (see FIG. 4) that is detachable in the axial direction. The drive motor 53 is controlled by instructions from the control unit (CPU) 50 to rotate the developing screw 104a. The rotation is transmitted to the developing sleeve 102 by a gear 170 (see FIG. 4) provided on the shaft of the developing screw 104a, a sleeve gear 171 (see FIG. 4) provided on the developing sleeve shaft, and an intermediate gear (not shown).

[0038] The rotation of the developing screw 104a is transmitted by a gear train 160 on the opposite side to which the coupling 54 is connected, and the stirring screw 104b, the developing screw 104a, and the winding shaft 600 rotate together. The developing sleeve 102, the developing screw 104a, the stirring screw 104b, and the winding shaft 600 form a single gear train by the gear train 160. When the developing screw 104a rotates, the output gear 151 at the end rotates. The idler gear 150 meshing with the output gear 151 rotates the winding shaft 600 through the meshing of a gear 153 and a gear 154 connected to the winding shaft 600. The gears 153 and 154 are configured to be significantly decelerated using a worm gear and a worm wheel so that the torque required for the winding shaft 600 to peel off the sealing sheet 51a can be secured.

[0039] On the other hand, the stirring screw gear 155 that rotates the stirring screw 104 b is in mesh with the output gear 151 .

[0040] These drive gear trains are all connected in the same series, and are configured so that when the coupling 54 rotates, all the gears are also driven to rotate. Moreover, the gear trains in the same series here refer to drive transmission paths in which the coupling 54 and the stirring screw 104b, the coupling 54 and the winding shaft 600, and the sleeve gear 171 are directly connected by meshing gears, respectively. Moreover, the gear trains branching off from the gears in series are considered to be the same as the branch gears in terms of the series, and the directly connected gear trains are considered to be in the same series, regardless of the length of the gear train after branching or the number of branches.

[0041] <Explanation of the operation during initialization of the development drive> The operation of the drive mechanism of the developing device 100 will be described with reference to Figures 7 and 8. Figure 8 is a cross-sectional view taken along the line F-F in Figure 4, and shows the operation of the take-up part of the sealing sheet during the initialization operation of the developing device 100. Also, the developing container 101 in Figures 6 to 8 is omitted so that the internal structure of the developing container 101 can be seen.

[0042] The developing device 100 is mounted in the image forming device 200, or the developing device 100 is mounted in the image forming device 200 before shipment. The power source of the image forming device 200 supplies power to the drive motor 53 of the drive source M1 provided in the image forming device 200. Then, the rotational drive force is transmitted to the developing screw 104a through the coupling 54 attached to the shaft end of the developing screw 104a of the developing device 100. The developing screw 104a rotates in the direction of the arrow 104R shown in FIG. 6 during normal rotation. The output gear 151 provided at the shaft end of the developing screw 104a on the opposite side to the coupling 54 rotates, and the rotation is transmitted to the idler gear 150 with which it is meshed. The output gear 151 is also meshed with the stirring screw gear 155, and the rotational force is transmitted to the stirring screw 104b.

[0043] In addition, a bevel gear 150a is integrally provided on one end of the idler gear 150 that is engaged with another output gear 151. A bevel gear 152 is also integrally provided on one end of the worm gear 153. The bevel gears 152 and 150a are disposed with their rotation axes at 90° to each other and engage with each other. As a result, the rotational force transmitted to the idler gear 150 is transmitted to the worm gear 153 through the engagement of the bevel gears 152 and 150a. The worm wheel 154 is greatly decelerated by the worm gear 153 and the worm wheel 154 and rotates in the direction of the arrow. At this time, the worm gear 153 receives a reaction force from the worm wheel 154, and the worm gear 153 itself is urged in the direction of the arrow P shown in FIG. 8. Therefore, the gear meshing between the bevel gear 152 and the bevel gear 150a provided on the idler gear 150 is maintained.

[0044] 7. Meanwhile, the stirring screw gear 155 also starts to rotate in the direction of the arrow by the rotational driving force transmitted from the idler gear 150. In this manner, the winding shaft 600 and the stirring screw 104b operate simultaneously, and the sealing member 51 is released and the developer is supplied to the containing chamber 101a at the same time.

[0045] On the other hand, due to the influence of the distribution or storage of the developing device 100 before the sealing sheet 51a is opened (at the time of shipment), the developer in the storage chamber 101b may be in a compressed state (tapping state) in which the developer is compressed toward the downstream side of the conveying direction of the stirring screw 104b before the use of the developing device 100. When the developer in the storage chamber 101b is in a compressed state, the resistance of the compressed developer is applied when the stirring screw 104b is driven. When the developing device 100 is in a tapping state and the initial start-up (initialization operation of the development drive) is performed, the load torque of the drive motor 53 for rotating the stirring screw 104b increases. Then, when the load torque of the drive motor 53 becomes equal to or greater than a predetermined value, there is a risk of a screw lock occurring, in which the stirring screw 104b cannot be rotated.

[0046] Therefore, a rotational torque load detection means 58 is provided to detect the amount of current through the drive motor 53 and estimate the torque, and the drive motor 53 is stopped when an overload occurs. In particular, in the case where the stirring screw 104b is driven before the sealing member 51 is released as in this configuration, the developer cannot move in the direction T shown in FIG. 7, and the load of the developer in the storage chamber 101b continues to increase. As a result, the drive motor 53 is stopped by the rotational torque load detection means 58.

[0047] <Explanation of release operation before initialization of development drive> The configuration of the loosening operation before the initialization operation of the drive (development drive) of the developing device 100 according to the first embodiment will be described with reference to Figs. 9 and 10. Fig. 9 is an explanatory diagram of the configuration for loosening. Fig. 10 is an explanatory diagram of the loosening operation when the developing device 100 is attached to the image forming device 200. In order to suppress the occurrence of overload during the initial operation due to the compacted state of the developer after shipment, it is necessary to perform the loosening operation before the initial operation. The shipping state of the developing device 100 is assumed to be either a standalone state of the developing device 100 or a packed state in which the developing device 100 is attached to the main body of the image forming device 200. In order to perform a common operation in either state of the developing device 100, it is preferable that the loosening operation is configured to be executable when the developing device 100 is attached to the image forming device 200.

[0048] In the first embodiment, the loosening member 140 that loosens the developer is an agitating screw 104b, and the drive input member 141 for driving the loosening member 140 is an agitating screw gear 155.

[0049] The drive input member 141 is provided with an operating unit 143 that receives a drive from the outside. In the first embodiment, the operating unit 143 is a cross hole provided at the end of the drive input member 141, and can be driven from the outside by a tool that engages with the cross hole, such as a screwdriver. The loosening member 140, i.e., the stirring screw 104b, is driven via the drive input member 141 by driving with the tool. This makes it possible to loosen the developer sealed in the stirring chamber 101b by the sealing member 51. The loosening operation of the developing device 100 can be performed, for example, by repeating forward and reverse rotations multiple times. This allows the operator to eliminate the tapping state of the developing device 100 even when the developing device 100 is still attached to the image forming device 200.

[0050] Next, an unwinding operation of the developing device 100 when the developing device 100 is attached to the image forming device 200 will be described. The developing device 100 is attached to the image forming device 200 by opening a small door 201 inside the image forming device 200 and inserting the developing device 100 along the tray 202 in the direction of the rotation axis X of the developing sleeve 102. Therefore, the operating unit 143 that applies an external force for the unwinding operation of the developing device 100 needs to be located at the end of the developing device 100 on the front side in the rotation axis direction X. Also, in the case of a configuration in which a gear (drive transmission member) is provided at the end of the developing device 100 as in the first embodiment, it is necessary to provide a cover 144 (developer cover) at the end of the developing device 100 from the viewpoint of protecting the operator (serviceman, user). Therefore, in order to drive the unwinding member 140 from the outside, a hole (opening) that can drive the drive input member 141 is provided on the surface of the cover 144 that faces the drive input member 141. By providing this opening in the cover 144, an operator can access the operating portion 143 in order to manually rotate the release member 140 when the developing device 100 is attached to the image forming apparatus 200.

[0051] 11 will be used to explain the loosening operation from outside the main body of the image forming apparatus 200, that is, the loosening operation when replacing the developing device 100 with a new one. With this configuration, it is possible to perform the loosening operation after mounting the developing device 100 to the image forming apparatus 200. On the other hand, when the developing device 100 is outside the main body of the image forming apparatus 200, the developing device 100 can be held in a vertical position with the drive input portion 141 facing upward as shown in FIG. 11, and the loosening operation can be performed by using gravity together with the drive of the loosening member 140. Therefore, it is possible to loosen developer in a harder state (tapping state). As described above, the overload caused by the developer during the initial operation of the developing device 100 occurs especially when the developing device 100 is located downstream in the transport direction T of the stirring screw 104b in the developer-sealed storage portion 101b. Therefore, assuming that the developer is to be loosened with the developing device 100 in a vertical position, the loosening operation can be easily performed by making use of gravity by providing the operation unit 143 at the downstream end of the developing device 100 in the transport direction T of the stirring screw 104b as shown in Fig. 11. Also, when the developing device 100 is attached to the image forming device 200, the downstream end of the stirring screw 104b in the transport direction T is at the front side in the front-rear direction of the image forming device 200, which has the advantage that the operator can easily access the operation unit 143.

[0052] <Positional relationship between the developing device and the photosensitive drum during unwinding operation> Next, a description will be given of the positional relationship between the developing sleeve 102 and the photosensitive drum 1 when performing a release operation of the developing device 100. Fig. 12 is a diagram for explaining a cross-sectional configuration of the developing device 100 in a pressurized state. Fig. 13 is a diagram for explaining a cross-sectional configuration of the developing device 100 in a separated state.

[0053] In order for the developing device 100 to develop the electrostatic image formed on the photosensitive drum 1 and form a toner image on the photosensitive drum 1, the distance between the rotation centers of the developing sleeve 102 and the photosensitive drum 1 must be maintained at a first distance Y1. For this reason, in the first embodiment, the tray 202 on which the developing device 100 is mounted is pressurized by a pressurizing structure 203 (the developing device 100 is placed in a pressurized state) to maintain the distance Y1 (first distance).

[0054] For example, consider a case where an operator mistakenly manually drives the drive input member 141 when developer is supplied onto the developing sleeve 102 and carried on the developing sleeve 102, and the photosensitive drum 1 is stopped. In such a case, the developing sleeve 102 is also driven via the gears, and there is a risk that the photosensitive drum 1 will be damaged due to contact with the developer carried on the developing sleeve 102. Therefore, as shown in FIG. 12, during the release operation of the developing device 100, even in the above-mentioned case, the distance between the rotation center of the developing sleeve 102 and the rotation center of the photosensitive drum 1 must be a second distance Y2 that is greater than Y1 at which there is no risk of damaging the photosensitive drum 1.

[0055] Therefore, in the first embodiment, as shown in Fig. 14, in a closed state in which the small door 201 is closed so that the drive input member 141 cannot be driven, the tray 202 is pressurized by the pressurizing structure 203 as shown in Fig. 12. On the other hand, as shown in Fig. 15, in an open state in which the small door 201 is open so that the drive input member 141 can be driven, the tray 202 transitions to a non-pressurized state as shown in Fig. 13. Also, a configuration is realized in which the developing device 100 is separated so that the distance between the rotation center of the developing sleeve 102 and the rotation center of the photosensitive drum 1 becomes a second distance Y2.

[0056] In addition, even when the small door 201 is open, if the developing sleeve 102 is rotated in reverse by an external drive while the developer is carried on it, the developer is scraped off and piled up on the sheet 147 provided for preventing scattering in FIG. 13, and there is a risk of the toner scattering. Therefore, in order to make it possible to perform the unwinding operation of the developing device 100 only when the developing device 100 is in a separated state before the seal is released, the developing device 100 is provided with a removable member that prevents the drive input member from being driven by an external force when the developing device 100 is attached to the image forming device 100. This allows the operator to perform the unwinding operation only by removing the removable member during the unwinding operation of the developing device 100, and prevents the operator from performing the unwinding operation by mistake after the seal is released. In the first embodiment, the seal 147 is attached to the cover 144 as shown in FIG. 16 to prevent erroneous operation due to the removable member.

[0057] [Second embodiment] Another embodiment (second embodiment) of the present invention is shown below. Since the basic configuration is the same as that of the first embodiment, elements having substantially the same or corresponding functions and configurations as those of the first embodiment are given the same reference numerals, and detailed explanations are omitted. Only the components unique to the second embodiment are explained in detail.

[0058] The configuration of the small door 201 in the open state according to the second embodiment will be described with reference to FIG. 17, which is a front view of the small door 201 when it is opened. The configurations of the developing device 100 and the sealing and release drive mechanism thereof are the same as those of the first embodiment, and therefore will not be described. When the developing device 100 is mounted on the tray 202 in the image forming device 200, a cross-recessed screw is used as the fastening member 148 for fixing. Since the fastening with the screw is performed manually by a screwdriver, if the shape of the operating portion 143 of the drive input member 141 is also a cross-recessed shape, there is a possibility that the operator will drive the drive input member 141 by mistake. If the operator drives the drive input member 141 by mistake, there is a risk that the toner will scatter as the developing sleeve 102 rotates in the reverse direction as described in the first embodiment.

[0059] Therefore, in the second embodiment, the shape of operation portion 143 is made different from the shape of fastening operation portion 149 of fastening member 148 by making it a rectangular groove portion instead of a cross recess, so that it can be driven only with a flat-head screwdriver.

[0060] [Third embodiment] Another embodiment (third embodiment) of the present invention will be described. Since the basic configuration is the same as that of the first embodiment, elements having substantially the same or corresponding functions and configurations as those of the first embodiment will be given the same reference numerals and detailed explanations will be omitted, and only the components unique to the third embodiment will be described in detail.

[0061] FIG. 18 is a diagram for explaining the loosening operation of the developing device 100 according to the third embodiment. The configurations of the developing device 100 and the seal and its release drive mechanism are the same as those of the first embodiment, so they will not be described. In the third embodiment, the loosening member 140 may be a member different from the stirring screw 104b. As described above in the first embodiment, overload often occurs when the developer is downstream of the stirring screw 104b in the transport direction. For this reason, it is preferable to provide the loosening member 140 downstream of the stirring screw 104b in the transport direction and in a manner that does not interfere with the circulation of the developer.

[0062] Further, the driving of the drive input member 141 by the operating portion 143 using an external force can be achieved not only by driving with a tool as in the first embodiment, but also by pulling the sealing member wrapped around the loosening member 140 as shown in Fig. 18. When the sealing member is pulled out, the loosening member 140 is driven to release the compressed state of the agent inside the developing device 100. Then, when all the sealing members have been pulled out, the end of the loosening operation of the developing device 100 can be quantitatively grasped.

[0063] (Other embodiments) The present invention is not limited to the above-described embodiments, and various modifications (including organic combinations of the respective embodiments) are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0064] In the above embodiment, as shown in Fig. 1, the image forming apparatus 200 is configured to use the intermediate transfer belt 7, but the present invention is not limited to this. It is also possible to apply the present invention to an image forming apparatus configured to directly contact the recording material P with the photosensitive drum 1 in sequence to perform transfer. [Explanation of symbols]

[0065] 1 Photosensitive drum 51a Encapsulating sheet 51b Encapsulating sheet 53 Drive motor 100 Developing device 101a Developing Room 101b Mixing chamber 102 Developing sleeve 104a Development screw 104b Mixing screw 107a opening 107b opening 141 Driving input member 143 Operation section 200 Image forming device

Claims

1. A developer carrier that carries a developer containing toner and carrier for developing an electrostatic image formed on an image carrier; a first chamber for supplying the developer to the developer carrier; a second chamber separated from the first chamber by a partition wall, and through which the developer circulates between the second chamber and the first chamber; a first communication portion that allows the developer to communicate from the second chamber to the first chamber; a second communication portion that allows the developer to communicate from the first chamber to the second chamber; a first conveying screw disposed in the first chamber and configured to convey the developer in a first direction from the first communicating portion toward the second communicating portion; a second conveying screw disposed in the second chamber and configured to convey the developer in a second direction from the second communicating portion toward the first communicating portion; a pair of sealing members that seal the first communicating portion and the second communicating portion, respectively, to accommodate the initial developer in the second chamber; a drive transmission gear that transmits a drive force for rotating the second conveying screw to the second conveying screw; Equipped with The drive transmission gear is provided with an engagement portion with which a tool engages to input a drive force for rotating the second conveying screw to the drive transmission gear. A developing device characterized by:

2. When the first communicating portion and the second communicating portion are each sealed by the pair of sealing members, a driving force for rotating the second conveying screw can be input to the drive transmission gear via the engaging portion.

2. The developing device according to claim 1.

3. A driving force for rotating the second conveying screw in a first rotational direction is input to the drive transmission gear via the engaging portion, so that the second conveying screw can rotate in the first rotational direction; and, A driving force for rotating the second conveying screw in a second rotation direction opposite to the first rotation direction is input to the drive transmission gear via the engaging portion, whereby the second conveying screw is rotatable in the second rotation direction.

2. The developing device according to claim 1.

4. The drive transmission gear is provided on the rotation shaft of the second conveying screw.

2. The developing device according to claim 1.

5. Further provided with a gear cover covering the drive transmission gear in the rotational axis direction of the second conveying screw, In the rotational axis direction of the second conveying screw, the engagement portion is exposed through an opening of the gear cover.

5. The developing device according to claim 4.

6. The drive transmission gear is disposed downstream of the first communicating portion in the second direction.

2. The developing device according to claim 1.

7. The tool is a Phillips head screwdriver, The engaging portion is a groove portion into which the Phillips head screwdriver engages.

2. The developing device according to claim 1.

8. The tool is a flat-head screwdriver, The engagement portion is a groove portion into which the flat-head screwdriver engages.

2. The developing device according to claim 1.

9. A seal release mechanism that releases the sealing of each of the first communicating portion and the second communicating portion by the pair of sealing members using a driving force supplied from a driving source.

2. The developing device according to claim 1, further comprising:

10. The seal release mechanism has a rotatable winding shaft for winding up the pair of sealing members, and the winding shaft is rotationally driven in the winding direction by the driving force supplied from the drive source, and the pair of sealing members are wound up around the winding shaft that is rotationally driven in the winding direction, thereby releasing the seals of the first communicating portion and the second communicating portion by the pair of sealing members.

10. The developing device according to claim 9.

11. A method for stirring initial developer in a developing device comprising: a developer carrier that carries developer containing toner and carrier for developing an electrostatic image formed on an image carrier; a first chamber for supplying the developer to the developer carrier; a second chamber that is separated from the first chamber by a partition and through which the developer circulates between the first chamber and the second chamber; a first communication portion that allows the developer to communicate from the second chamber to the first chamber; a second communication portion that allows the developer to communicate from the first chamber to the second chamber; a first conveying screw that is disposed in the first chamber and conveys the developer in a first direction from the first communication portion toward the second communication portion; a second conveying screw that is disposed in the second chamber and conveys the developer in a second direction from the second communication portion toward the first communication portion; a pair of sealing members that seal the first communication portion and the second communication portion respectively to accommodate the initial developer in the second chamber; and a drive transmission gear that transmits a drive force for rotating the second conveying screw to the second conveying screw, an input step of inputting a driving force for rotating the second conveying screw to the drive transmission gear using a tool in a state in which the first communicating portion and the second communicating portion are respectively sealed by the pair of sealing members; a stirring step of inputting a driving force for rotating the second conveying screw to the drive transmission gear in the input step, thereby rotating the second conveying screw and stirring the initial developer; 10. A method for stirring an initial developer in a developing device, comprising:

12. The input step includes inputting a driving force for rotating the second conveying screw in a first rotation direction into the drive transmission gear using the tool, and inputting a driving force for rotating the second conveying screw in a second rotation direction opposite to the first rotation direction into the drive transmission gear using the tool; In the stirring step, a driving force for rotating the second conveying screw in the first rotation direction is input to the drive transmission gear in the input step, whereby the second conveying screw rotates in the first rotation direction and stirs the initial developer, and a driving force for rotating the second conveying screw in the second rotation direction is input to the drive transmission gear in the input step, whereby the second conveying screw rotates in the second rotation direction and stirs the initial developer.

12. The method for stirring initial developer in a developing device according to claim 11.

13. The input step includes inputting a driving force for rotating the second conveying screw to the drive transmission gear using the tool in an orientation of the developing device in which the drive transmission gear is oriented upward in the direction of gravity.

12. The method for stirring initial developer in a developing device according to claim 11.

14. The input step includes inputting a driving force for rotating the second conveying screw to the drive transmission gear using the tool when the developing device is not attached to the image forming apparatus.

12. The method for stirring initial developer in a developing device according to claim 11.

15. The input step includes inputting a driving force for rotating the second conveying screw to the drive transmission gear using the tool while the developing device is mounted on the image forming apparatus.

12. The method for stirring initial developer in a developing device according to claim 11.

16. The drive transmission gear is provided on the rotation shaft of the second conveying screw.

12. The method for stirring initial developer in a developing device according to claim 11.

17. The developing device further includes a gear cover that covers the drive transmission gear in the direction of the rotation axis of the second conveying screw, In the rotational axis direction of the second conveying screw, the engagement portion is exposed through an opening of the gear cover.

17. The method for stirring initial developer in a developing device according to claim 16.

18. The drive transmission gear is disposed downstream of the first communicating portion in the second direction.

12. The method for stirring initial developer in a developing device according to claim 11.

19. The tool is a Phillips head screwdriver.

12. The method for stirring initial developer in a developing device according to claim 11.

20. The tool is a flat-head screwdriver.

12. The method for stirring initial developer in a developing device according to claim 11.

Images