Image forming apparatus

Abstract

To appropriately maintain the gap between a developer carrier and an image carrier.SOLUTION: A first drive transmission gear 42a is urged by a first spring 46a to be brought into contact with a first drive gear 45a. A second drive transmission gear 42b is urged by a second spring 46b to be brought into contact with a second drive gear 45b. With the first drive transmission gear 42a in contact with the first drive gear 45a and the second drive transmission gear 42b in contact with the second drive gear 45b, a first direction is defined as a direction in which the first spring 46a urges the first drive transmission gear 42a against the first drive gear 45a when a driving force is not input to a first drive input unit 451, and a second direction is defined as a direction in which the second spring 46b urges the second drive transmission gear 42b against the second drive gear 45b when a driving force is not input to a second drive input unit 452. In this case, the second direction has a component of a force in the opposite direction to the first direction with respect to a straight line S connecting the center of rotation of the first drive gear 45a and the center of rotation of the second drive gear 45b.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction machine having a plurality of these functions.

Background Art

[0002] In an image forming apparatus, an electrostatic latent image formed on an image carrier is developed with a developer by a developing device to form a toner image. Such a developing device is driven by transmitting a driving force from a motor provided in the image forming apparatus main body. As such a driving configuration, a configuration in which the driving force from the motor is transmitted to the developing device via a driving transmission gear and a driving gear has been conventionally known (for example, Patent Document 1).

[0003] In the case of the configuration described in Patent Document 1, the driving transmission gear is provided so as to be movable between a transmission position where the driving transmission gear can transmit driving force to the driving gear and a retracted position where the driving transmission gear is retracted from the driving gear with respect to the driving gear connected to the driving configuration (developer carrier) of the developing device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, the developing device includes a developer carrier for supplying a developer to the image carrier and developing the electrostatic latent image, and is pressurized toward the image carrier in order to appropriately maintain the gap between the developer carrier and the image carrier. On the other hand, as described above, in the configuration in which the driving transmission gear can be moved between the transmission position and the retracted position, the driving transmission gear is biased toward the driving gear in order to mesh the driving transmission gear with the driving gear.

[0006] Therefore, when the drive transmission gear is moved to the transmission position and brought into contact with the drive gear, a force caused by the biasing force that energizes the drive transmission gear is also generated in the developing device. Depending on the direction of this force, the pressure exerted on the developing device toward the image carrier may become unstable, making it difficult to maintain an appropriate gap between the developer carrier and the image carrier. If the gap is not appropriate, there is a risk of image defects.

[0007] The present invention aims to appropriately maintain the gap between the developer carrier and the image carrier. [Means for solving the problem]

[0008] The present invention relates to an image forming apparatus, comprising: an image carrier; a developing container for containing a developer; a developer carrier for carrying and transporting the developer in the developing container to develop an electrostatic latent image formed on the image carrier; a transport member for transporting the developer within the developing container; a first drive gear for driving the developer carrier; a second drive gear for driving the transport member; a mounting section for mounting the developing apparatus; a first drive transmission gear that meshes with the first drive gear and inputs drive to the first drive gear when the developing apparatus is mounted on the mounting section; a first biasing section that biases the first drive transmission gear toward the first drive gear, to which driving force is input; a second drive transmission gear that meshes with the second drive gear and inputs drive to the second drive gear when the developing apparatus is mounted on the mounting section; and a second biasing section that biases the second drive transmission gear toward the second drive gear. The device comprises a second drive input section to which driving force is input, and a contact / separation mechanism that brings the first drive transmission gear and the second drive transmission gear into contact with and separates from the first drive gear and the second drive transmission gear, respectively, when the developing device is attached to and detached from the mounting section, and when the contact / separation mechanism brings the first drive transmission gear into contact with the first drive gear and the second drive transmission gear into contact with the second drive gear, the direction in which the first biasing section biases the first drive transmission gear is defined as the first direction when no driving force is input to the first drive input section, and the direction in which the second biasing section biases the second drive transmission gear is defined as the second direction when no driving force is input to the second drive input section, wherein the second direction has a force component in the opposite direction to the first direction with respect to the straight line connecting the rotation center of the first drive gear and the rotation center of the second drive gear.

[0009] Furthermore, the present invention relates to an image forming apparatus comprising: an image carrier; a developing container for containing a developer; a first developer carrier for carrying and transporting the developer in the developing container in order to develop an electrostatic latent image formed on the image carrier; a second developer carrier arranged in parallel with the first developer carrier with a predetermined gap between them for carrying and transporting the developer in order to develop an electrostatic latent image formed on the image carrier; a transport member for transporting the developer within the developing container; and a first drive gear for driving the first developer carrier and the second developer carrier. A developing device having a first drive gear that drives the transport member, a mounting part for mounting the developing device, a first drive transmission gear that meshes with the first drive gear and inputs drive to the first drive gear when the developing device is mounted on the mounting part, and a first biasing part that biases the first drive transmission gear toward the first drive gear, and a first drive input part to which driving force is input, and when the developing device is mounted on the mounting part, a first drive input part that meshes with the second drive gear and inputs drive to the second drive gear The device comprises a second drive input unit into which a driving force is input, and a second biasing unit that biases the second drive transmission gear toward the second drive gear, and a contact / separation mechanism that brings the first drive transmission gear and the second drive transmission gear into contact with and separates from the first drive gear and the second drive gear, respectively, when the contact / separation mechanism brings the first drive transmission gear into contact with the first drive gear and the second drive transmission gear into contact with the second drive gear, and when no driving force is input to the first drive input unit, the direction in which the first drive transmission gear biases the first drive transmission gear by the first biasing unit is defined as the first direction, and when no driving force is input to the second drive input unit, the direction in which the second drive transmission gear biases the second drive gear by the second biasing unit is defined as the second direction, the second direction has a force component in the opposite direction to the first direction with respect to the straight line connecting the rotation center of the first drive gear and the rotation center of the second drive gear. [Effects of the Invention]

[0010] According to the present invention, the gap between the developer carrier and the image carrier can be appropriately maintained. [Brief explanation of the drawing]

[0011] [Figure 1] A schematic cross-sectional view of the image forming apparatus according to the first embodiment. [Figure 2] A schematic cross-sectional view of the developing apparatus according to the first embodiment. [Figure 3] A schematic longitudinal cross-sectional view of the developing apparatus according to the first embodiment. [Figure 4] A perspective view showing the drive configuration of a developing apparatus according to the first embodiment. [Figure 5] A perspective view showing the drive configuration on the main body side of the image forming apparatus according to the first embodiment. [Figure 6] A vertical cross-sectional view of the developing apparatus according to the first embodiment when it is attached to the main body of the image forming apparatus, showing (a) the state at the start of insertion, (b) the state during insertion, and (c) the state when insertion is complete. [Figure 7] A diagram showing a part of the drive configuration according to the first embodiment, viewed from the rear side of the image forming apparatus body, with (a) the drive transmission gear and the drive gear meshed together and (b) the drive transmission gear and the drive gear separated. [Figure 8] A diagram showing the relationship of forces generated in the drive configuration according to the first embodiment. [Figure 9] A schematic cross-sectional view of the developing apparatus according to the second embodiment. [Modes for carrying out the invention]

[0012] <First Embodiment> The first embodiment will be described with reference to Figures 1 to 8. First, the general configuration of the image forming apparatus of this embodiment will be described.

[0013] [Image forming apparatus] FIG. 1 is a schematic cross-sectional view showing an image forming apparatus 100 according to the present embodiment. The image forming apparatus 100 is a tandem type intermediate transfer type image forming apparatus in which a plurality of, in this embodiment, four image forming units 1Y, 1M, 1C, and 1K are arranged in series on the horizontal portion of an intermediate transfer belt 20. These image forming units 1Y, 1M, 1C, and 1K are arranged inside the image forming apparatus main body 101 (inside the image forming apparatus).

[0014] The image forming apparatus 100 forms a full-color image on a recording material S by an electrophotographic method according to an image signal transmitted from an external device such as a host computer. Note that the order of these image forming units is an example, and is not limited to this position, and further, the number of these image forming units is not limited.

[0015] The image forming units 1Y, 1M, 1C, and 1K respectively form toner images of yellow, magenta, cyan, and black colors on photosensitive drums 11Y, 11M, 11C, and 11K as image carriers, and perform primary transfer to the same image position on the intermediate transfer belt 20. The photosensitive drums 11Y, 11M, 11C, and 11K are cylindrical photoreceptors.

[0016] Around the photosensitive drum 11Y that forms a yellow toner image, a charging device 12Y, an exposure device 13Y, a developing device 14Y, and a cleaning device 15Y are arranged. The charging device 12Y uniformly charges the surface of the photosensitive drum 11Y. The exposure device 13Y irradiates the photosensitive drum 11Y with image light to form an electrostatic latent image on the surface. The developing device 14Y transfers toner to the electrostatic latent image formed on the photosensitive drum 11Y and develops it as a toner image. The cleaning device 15Y removes the toner remaining on the photosensitive drum 11Y after the primary transfer of the toner image. The configuration for forming magenta, cyan, and black toner images is understood by replacing the subscript Y with M, C, and K in the above description.

[0017] The intermediate transfer belt 20 is an endless belt stretched by a plurality of stretching rollers, and rotates by inputting drive to any one of these rollers. The stretching rollers include primary transfer rollers 21Y, 21M, 21C, 21K and a secondary transfer inner roller 22, and these rollers are supported by an intermediate transfer belt frame (not shown). The primary transfer rollers 21Y, 21M, 21C, 21K are arranged at positions where they contact the photosensitive drums 11Y, 11M, 11C, 11K via the intermediate transfer belt 20, and form a primary transfer unit. When a primary transfer voltage is applied to the primary transfer rollers 21Y, 21M, 21C, 21K, the toner images formed on the photosensitive drums 11Y, 11M, 11C, 11K are primarily transferred onto the intermediate transfer belt 20. A secondary transfer member 23 is arranged at a position where it contacts the secondary transfer inner roller 22 via the intermediate transfer belt 20, and forms a secondary transfer unit. When a secondary transfer voltage is applied to either the secondary transfer inner roller 22 or the secondary transfer member 23, the toner image on the intermediate transfer belt 20 is secondarily transferred onto the recording material S. The transfer residual toner and the unnecessary toner image remaining on the intermediate transfer belt 20 after secondary transfer are removed by the cleaning device 30.

[0018] On the other hand, the recording material S stored in the paper feed cassettes 61, 62 is conveyed to the paper feed conveyance path 81 by the rotation of the paper feed rollers 71, 72. The recording material S is a sheet material such as paper or a plastic sheet, for example. The registration roller 74 feeds the recording material S to the secondary transfer unit in synchronization with the toner image on the intermediate transfer belt 20. The recording material S onto which the toner image has been transferred is conveyed to the fixing device 5 and heat-pressed, whereby the toner image is fixed on the surface of the recording material S and a full-color image is fixed. Thereafter, the recording material S is sent out to the discharge tray 64 through the discharge conveyance path 82. Note that the positions and numbers of the paper feed cassettes and the discharge tray are just examples and are not limited to these positions and numbers.

[0019] [Developing device] Next, the configuration of the developing apparatus 14Y to 14K of this embodiment will be described using Figures 2 and 3. Note that the developing apparatuses 14Y to 14K have the same configuration except for the development color, so the subscripts Y to K will be omitted below. The same applies to the photosensitive drums 11Y to 11K. Figure 2 is a cross-sectional view of the developing apparatus 14 cut in a direction perpendicular to the rotation axis direction of the first developing sleeve 441 and the second developing sleeve 442. Figure 3 is a cross-sectional view cut along the rotation axis direction of the first developing sleeve 441 and the second developing sleeve 442 at the portions of the first transport screw 443 and the second transport screw 444.

[0020] The developing device 14 is detachable from the image forming apparatus body 101 (Figure 1). Specifically, the developing device 14 can be inserted into and removed from the mounting section 110 of the image forming apparatus body 101 in the direction perpendicular to the plane of the paper in Figure 1. The developing device 14 can also be separated from the photosensitive drum 11 in the direction of arrow A shown in Figure 1. That is, when removing the developing device 14 from the image forming apparatus body 101, the developing device 14 is separated from the photosensitive drum 11 in the direction of arrow A. On the other hand, when the developing device 14 is inserted into the image forming apparatus body 101 and mounted in the mounting section 110, the developing device 14 is moved in the direction opposite to arrow A so that the first developing sleeve 441 and the second developing sleeve 442 face the photosensitive drum 11 with a predetermined gap between them. In this process, the developing device 14 is pressurized toward the photosensitive drum 11 by a pressurizing member 140 (Figure 2), such as a spring, in the pressurizing direction (from the rotation center of the first developing sleeve 441 toward the rotation center of the photosensitive drum 11, and from the rotation center of the second developing sleeve 442 toward the rotation center of the photosensitive drum 11). Part of the developing device 14 and part of the photosensitive drum 11 come into contact with each other, thereby maintaining the aforementioned gaps (the gap between the first developing sleeve 441 and the photosensitive drum 11, and the gap between the second developing sleeve 442 and the photosensitive drum 11) at an appropriate size.

[0021] In embodiments where flanges are provided at both ends in the longitudinal direction of the photosensitive drum 11, for example, abutment rollers provided at both ends in the longitudinal direction of the first developing sleeve 441 and the second developing sleeve 442 are abutted against the flanges provided at both ends in the longitudinal direction of the photosensitive drum 11. This maintains the above-mentioned gap at an appropriate size. On the other hand, in embodiments where flanges are not provided at both ends in the longitudinal direction of the photosensitive drum 11, for example, abutment rollers provided at both ends in the longitudinal direction of the first developing sleeve 441 and the second developing sleeve 442 are abutted against the raw tube of the photosensitive drum 11. This maintains the above-mentioned gap (the gap between the first developing sleeve 441 and the photosensitive drum 11, and the gap between the second developing sleeve 442 and the photosensitive drum 11) at an appropriate size.

[0022] As shown in Figure 2, the developing apparatus 14 has a developing container 410 for containing the developer. The developer in this embodiment is a so-called two-component developer containing a non-magnetic toner and a magnetic carrier. The developing container 410 rotatably supports a first developing sleeve 441 as a first developer carrier, and a second developing sleeve 442 as a developer carrier and a second developer carrier. The first developing sleeve 441 and the second developing sleeve 442 are arranged parallel to the rotation axis direction of the photosensitive drum 11, and develop the electrostatic latent image on the surface of the photosensitive drum 11 with the developer. The second developing sleeve 442 is located below the first developing sleeve 441 and is arranged in parallel with the first developing sleeve 441 with a predetermined gap between them.

[0023] Furthermore, the developing container 410 is provided with a regulating blade 445 that regulates the thickness of the developer layer supported on the first developing sleeve 441. The first developing sleeve 441 carries the developer supplied from the developing chamber 410a (described later) on its surface and transports it. The second developing sleeve 442 is located below the first developing sleeve 441 and carries the developer received from the first developing sleeve 441 on its surface and transports it. The first developing sleeve 441 and the second developing sleeve 442 are each formed in a cylindrical shape, with magnets positioned inside in a non-rotating manner. The first developing sleeve 441 and the second developing sleeve 442 are each driven to rotate in the direction of the arrows shown in Figure 2, and carry and transport the developer by the magnetic attraction force of the magnets.

[0024] The developing container 410 is divided by a horizontally extending partition wall 410c into an upper developing chamber (developer transport path) 410a as the first chamber, and a stirring chamber (developer transport path) 410b located below the developing chamber 410a as the second chamber. The developing chamber 410a is a functional chamber for supplying developer to the first developing sleeve 441. The stirring chamber 410b is a functional chamber for receiving and stirring the recovered developer recovered from the second developing sleeve 442, the excess developer that was not supplied to the first developing sleeve 441 in the developing chamber 410a, and the replenishment developer supplied from outside the developing device 4.

[0025] The developing chamber 410a and the agitation chamber 410b are each provided with a transport member and a first transport screw 443 as the first transport member and a second transport screw 444 as the second transport member. Both the first transport screw 443 and the second transport screw 444 are screw members with helical blades on a rotating shaft that is positioned substantially parallel to the rotation axis direction (longitudinal direction) of the first developing sleeve 441 and the second developing sleeve 442.

[0026] Furthermore, as shown in Figure 3, the partition wall 410c is provided with a first connecting section 410d and a second connecting section 410e at both longitudinal ends, which are transfer sections (developer transport paths) for transporting developer between the developing chamber 410a and the stirring chamber 410b. The first connecting section 410d has an opening that allows developer to move from the stirring chamber 410b to the developing chamber 410a. The second connecting section 410e has an opening that allows developer to move from the developing chamber 410a to the stirring chamber 410b.

[0027] The first transport screw 443 is positioned opposite the first developing sleeve 441 and supplies developer to the first developing sleeve 441 while rotating to agitate and transport the developer in a first direction from the first connecting section 410d toward the second connecting section 410e. The second transport screw 444 rotates to agitate and transport the developer in a second direction from the second connecting section 410e toward the first connecting section 410d. The second transport screw 444 is positioned below the first transport screw 443 with respect to the direction of gravity, and the second direction is opposite to the first direction. The rotational movements of the first transport screw 443 and the second transport screw 444 circulate the developer in the developing container while agitating and transporting it.

[0028] The developing device 14 is provided with a recovery member 446 positioned opposite the second developing sleeve 442 below it and positioned approximately parallel to the rotation axis direction of the second developing sleeve 442. The recovery member 446 is spaced at a predetermined distance from the second developing sleeve 442 and recovers the undeveloped developer from the second developing sleeve 442. That is, the recovery member 446 recovers the remaining developer on the second developing sleeve 442 (on the developer carrier, on the second developer carrier) after developing the electrostatic latent image formed on the photosensitive drum 11. The recovery member 446 is a cylindrical member and rotates together with the second developing sleeve 442.

[0029] Furthermore, the developing apparatus 14 is provided with a third transport member and a third transport screw 447 adjacent to the recovery member 446, which recovers the undeveloped developer from the second developing sleeve 442 and transports the developer recovered by the recovery member 446 to the second transport screw 444 while agitating it. Specifically, the third transport screw 447 is positioned below the second developing sleeve 442 and recovers, agitates, and transports the developer from the second developing sleeve 442. This third transport screw 447 is a screw member with spiral blades on a rotating shaft that is positioned substantially parallel to the rotational axis direction of the first developing sleeve 441 and the second developing sleeve 442.

[0030] In this type of developing apparatus 14, the first developing sleeve 441 rotates clockwise in Figure 2 during development, and developer is supplied from the developing chamber 410a, carrying a two-component developer whose layer thickness is regulated by the cutting of magnetic brushes by the regulating blade 445. This is then transported to the developing area A1 opposite the photosensitive drum 11, and the developer is supplied to the electrostatic latent image formed on the photosensitive drum 11 to develop the latent image. The photosensitive drum 11 rotates counterclockwise in Figure 2.

[0031] Meanwhile, the second developing sleeve 442 rotates clockwise in Figure 2 during development, and the developer is transferred from the surface of the first developing sleeve 441 as it passes through the developing region A1. The developer transferred to the second developing sleeve 442 is transported to the developing region A2, which is downstream of the developing region A1 in the direction of rotation of the photosensitive drum 11, and again supplies the developer to the electrostatic latent image formed on the photosensitive drum 11 to develop the latent image. After that, the developer that contributed to the development is recovered from the second developing sleeve 442 by the recovery member 446, transported by the third transport screw 447, and transferred to the second transport screw 444.

[0032] [Drive system configuration for developing equipment] Next, the drive configuration of the developing apparatus 14 will be explained using Figures 4 to 8. First, using Figures 4 and 5, the overall drive configuration of the developing apparatus 14, which transmits the drive from the image forming apparatus body 101 to the developing apparatus 14 and drives the developing apparatus 14, will be explained. Figure 4 is a perspective view of the developing apparatus 14 as seen from the rear side. Figure 5 is a perspective view of the drive configuration on the image forming apparatus body 101 side as seen from the developing apparatus 14 side.

[0033] The developing device 14 receives driving force from a drive source (motor) in the main body of the image forming apparatus, causing the first developing sleeve 441, the second developing sleeve 442, the first transport screw 443, the second transport screw 444, and the third transport screw 447 to rotate. At this time, the developing device 14 receives drive from two different drive sources, the first drive gear 45a and the second drive gear 45b, respectively. Specifically, as shown in Figure 4, drive is input from the first motor 102, which serves as the first drive source provided in the main body of the image forming apparatus 101, to the first drive gear (sleeve drive gear) 45a via the first drive input unit 451. In addition, drive is input from the second motor 103, which serves as the second drive source provided in the main body of the image forming apparatus 101, to the second drive gear (screw drive gear) 45b via the second drive input unit 452.

[0034] Furthermore, the drive input to the first drive gear 45a and the second drive gear 45b may be supplied from a single motor via a clutch. By switching the power connection and disconnection using the clutch, they may be driven individually or simultaneously. In other words, as long as the first drive gear 45a and the second drive gear 45b can be driven independently of each other, they may be supplied with drive from separate motors, or they may be supplied with drive from a single motor via a clutch.

[0035] The first drive gear 45a transmits the driving force input from the first drive input unit 451 to the first developing sleeve 441, the second developing sleeve 442, and the third transport screw 447. That is, the first drive gear 45a forms a gear train together with the gear connected to the first developing sleeve 441, the gear connected to the second developing sleeve 442, and the gear connected to the third transport screw 447. As the first drive gear 45a rotates, driving force is transmitted to each gear, causing the first developing sleeve 441, the second developing sleeve 442, and the third transport screw 447 to rotate, respectively.

[0036] The second drive gear 45b transmits the driving force input from the second drive input unit 452 to the first conveying screw 443 and the second conveying screw 444. That is, the second drive gear 45b, together with the gear connected to the first conveying screw 443 and the gear connected to the second conveying screw 444, constitutes a gear train. As the second drive gear 45b rotates, the driving force is transmitted to each gear, causing the first conveying screw 443 and the second conveying screw 444 to rotate, respectively. In other words, the developing apparatus 14 of this embodiment has a configuration in which the driving force input from the two drive input units is transmitted to each part via separate drive transmission paths (e.g., gear trains).

[0037] [Configuration of the drive input section] Next, the configurations of the first drive input unit 451 and the second drive input unit 452 will be described using Figures 4 and 5. The first drive input unit 451 and the second drive input unit 452 are provided on the main body 101 of the image forming apparatus. Specifically, they are provided on the rear side in the insertion direction of the developing apparatus 14, which will be described later, and are connected to the developing apparatus 14 so as to transmit power when the developing apparatus 14 is inserted to a predetermined position in the mounting section 110 (Figure 1).

[0038] The first drive input unit 451 includes a first drive transmission gear 42a, a first pivot center gear 41a, a first housing 43a, and a first spring 46a as a first biasing unit. The first drive transmission gear 42a meshes with the first drive gear 45a and inputs drive to the first drive gear 45a. The first pivot center gear 41a is positioned to mesh with the first drive transmission gear 42a. The first housing 43a is provided to pivot together with the first drive transmission gear 42a around the first pivot center gear 41a. The first spring 46a biases the first housing 43a so that the first drive transmission gear 42a moves toward the first drive gear 45a.

[0039] The second drive input unit 452 includes a second drive transmission gear 42b, a second pivot center gear 41b, a second housing 43b, and a second spring 46b as a second biasing unit. The second drive transmission gear 42b meshes with the second drive gear 45b and inputs drive to the second drive gear 45b. The second pivot center gear 41b is positioned to mesh with the second drive transmission gear 42b. The second housing 43b is provided to pivot together with the second drive transmission gear 42b around the second pivot center gear 41b. The second spring 46b biases the second housing 43b so that the second drive transmission gear 42b moves toward the second drive gear 45b.

[0040] Specifically, the first and second pivot center gears 41a and 41b are rotatably supported by pivot center shafts 61a and 61b, respectively, which communicate with holes provided in the first and second housings 43a and 43b. In addition, the first and second drive transmission gears 42a and 42b are rotatably supported by drive transmission shafts 60a and 60b, respectively, which communicate with holes provided in the first and second housings 43a and 43b.

[0041] The pivot shafts 61a and 61b, which are in communication with the first and second pivot center gears 41a and 41b, rotate due to the driving force transmitted from the first motor 102 and the second motor 103, respectively. The pivot shafts 61a and 61b then rotate together with the first and second pivot center gears 41a and 41b, respectively. The first and second pivot center gears 41a and 41b and the first and second drive transmission gears 42a and 42b are always meshed together, and the rotation of the first and second pivot center gears 41a and 41b causes the first and second drive transmission gears 42a and 42b to rotate. In other words, the driving force from the first motor 102 and the second motor 103 is transmitted to the first and second drive transmission gears 42a and 42b via the pivot shafts 61a and 61b and the first and second pivot center gears 41a and 41b, respectively.

[0042] [Processing of inserting and removing the developing device] Next, with reference to Figures 4 and 5, the insertion and removal configuration of the developing device 14 into the image forming apparatus body 101 will be explained using Figures 6(a) to (c). Figure 6 shows the insertion of the developing device 14 into the image forming apparatus body 101, and is a view of the image forming apparatus body 101 from the left side of Figure 1. As described above, the first and second drive input units 451 and 452 are such that the first and second drive transmission gears 42a and 42b can pivot together with the first and second housings 43a and 43b around the pivot center axes 61a and 61b of the first and second pivot center gears 41a and 41b. In this embodiment, this configuration allows the first and second drive transmission gears 42a and 42b to come into contact with or separate from the first and second drive gears 45a and 45b when inserting or removing the developing device 14 into the image forming apparatus body 101.

[0043] In this embodiment, the developing apparatus 14 has a contact / separation mechanism 480 that allows the first and second drive transmission gears 42a and 42b to come into contact with or separate from the first and second drive gears 45a and 45b when the developing apparatus 14 is attached to or detached from the image forming apparatus body 101. The contact / separation mechanism 480 comprises guide arms 481a and 481b provided on the first and second housings 43a and 43b, pins 49a and 49b as protrusions provided at the tips of the guide arms 481a and 481b, and guide cams 48a and 48b. Furthermore, the contact / separation mechanism 480, through the engagement of pins 49a and 49b with induction cams 48a and 48b, is capable of moving the first and second drive transmission gears 42a and 42b between a contact position (transmission position) where they abut against the first and second drive gears 45a and 45b, and a retracted position where they are retracted from the first and second drive gears 45a and 45b, in conjunction with the insertion and removal operation (attachment / detachment operation) of the developing device 14.

[0044] As shown in Figure 4, the first drive input unit 451 and the second drive input unit 452 are arranged to sandwich the first drive gear 45a and the second drive gear 45b provided in the developing device 14. As shown in Figures 5 and 6(a) to (c), the guide arms 481a and 481b are provided to protrude toward the upstream side in the insertion direction of the developing device 14, and pins 49a and 49b are provided at the tips of each so as to protrude toward the first drive gear 45a and the second drive gear 45b.

[0045] The guide cams 48a and 48b are provided at the rear (downstream, front) end of the developing device 14 in the insertion direction and have cam surfaces 482a and 482b whose angle changes along the insertion direction. As will be described later, the cam surfaces 482a and 482b engage with pins 49a and 49b when the developing device 14 is inserted or removed. As the insertion and removal operation progresses, the pins 49a and 49b move along the cam surfaces 482a and 482b, causing the guide arms 481a and 481b and the first and second housings 43a and 43b to move.

[0046] The first spring 46a is positioned to span between the end of the first housing 43a opposite to the pivot axis 61a and the frame 101A of the image forming apparatus body 101, biasing the first housing 43a and the first drive transmission gear 42a toward the first drive gear 45a. Similarly, the second spring 46b is positioned to span between the end of the second housing 43b opposite to the pivot axis 61b and the frame 101A of the image forming apparatus body 101, biasing the second housing 43b and the second drive transmission gear 42b toward the second drive gear 45b.

[0047] When the developing device 14 is inserted into the image forming apparatus body 101, as shown in Figure 6(a), the cam surfaces 482a and 482b of the induction cams 48a and 48b attached to the developing device 14 come into contact with the pins 49a and 49b on the image forming apparatus body 101 side. In the initial stage of contact, the pins 49a and 49b move up along the slopes of the cam surfaces 482a and 482b of the induction cams 48a and 48b, and consequently, the first and second drive transmission gears 42a and 42b supported by the first and second housings 43a and 43b move to their retracted positions.

[0048] As shown in Figure 6(b), as the developing device 14 is further inserted, the pins 49a and 49b climb the slopes of the cam surfaces 482a and 482b and reach the flat surface. Then, the first and second drive transmission gears 42a and 42b complete their retracted position. Subsequently, just before the insertion of the developing device 14 is completed, that is, just before reaching the predetermined position of the mounting section 110 (Figure 1), the biasing force of the first and second springs 46a and 46b (see Figure 5) attached to the first and second housings 43a and 43b causes the pins 49a and 49b to begin descending along the slope on the upstream side in the insertion direction of the cam surfaces 482a and 482b. Accordingly, the first and second drive transmission gears 42a and 42b begin to move to the contact position, that is, to the position where they mesh with the first and second drive gears 45a and 45b.

[0049] In this way, just before the insertion of the developing device 14 is completed, the first and second drive transmission gears 42a, 42b and the first and second drive gears 45a, 45b begin to mesh, and as shown in Figure 6(c), when the insertion of the developing device 14 is completed (when the developing device 14 reaches a predetermined position in the mounting section 110), the pins 49a, 49b separate from the cam surfaces 482a, 482b of the induction cams 48a, 48b, and the meshing of the gears is completed. With this configuration, the first and second drive transmission gears 42a, 42b and the first and second drive gears 45a, 45b can be meshed without interfering with each other. Then, driving force can be transmitted from the first and second drive transmission gears 42a, 42b to the first and second drive gears 45a, 45b.

[0050] [Relationship between pressurized and unpressurized positions in the developing apparatus] Next, the relationship between the first and second drive input units 451, 452 and the first and second drive gears 45a, 45b in the pressurized position and the unpressurized position of the developing device 14 relative to the photosensitive drum 11 will be explained using Figures 7(a) and (b). As described above, when the developing device 14 is mounted on the mounting unit 110, it is in a pressurized position, pressed toward the photosensitive drum 11. On the other hand, when the developing device 14 is withdrawn from the mounting unit 110, the developing device 14 is moved to an unpressurized position, separated from the pressurized position. That is, the developing device 14 is movable between the pressurized position and the unpressurized position. In this embodiment, the switching of the pressurized state of the developing device 14 is performed by the contact between the induction cams 48a, 48b and the pins 49a, 49b, which switches the position between the transmission position and the retracted position when the developing device 14 is inserted into or removed from the mounting unit 110 as described above.

[0051] Figures 7(a) and 7(b) show the meshing of the first and second drive transmission gears 42a, 42b and the first and second drive gears 45a, 45b as viewed from the rear side of the image forming apparatus body 101. Figure 7(a) shows the positional relationship of the first and second drive transmission gears 42a, 42b and the first and second drive gears 45a, 45b in the pressurized position of the developing apparatus 14, and the positions of the pins 49a, 49b relative to the induction cams 48a, 48b at that time. Figure 7(b) shows the positional relationship of the first and second drive transmission gears 42a, 42b and the first and second drive gears 45a, 45b in the non-pressurized position of the developing apparatus 14, and the positions of the pins 49a, 49b relative to the induction cams 48a, 48b at that time.

[0052] As shown in Figure 7(a), in the pressurized position, the pins 49a and 49b are spaced apart from the slopes of the cam surfaces 482a and 482b of the induction cams 48a and 48b, which is the same position as when the developing device 14 is fully inserted, as shown in Figure 6(c). At this time, the first and second drive transmission gears 42a and 42b and the first and second drive gears 45a and 45b are meshed, and the driving force can be appropriately transmitted to the developing device 14.

[0053] On the other hand, as shown in Figure 7(b), in the non-pressurized position, the developing device 14 moves in the -x direction (to the right in Figure 7(b)) from the pressurized position, and accordingly, the pins 49a and 49b climb the slopes of the cam surfaces 482a and 482b of the induction cams 48a and 48b. When the pins 49a and 49b reach the flat portion of the cam surfaces 482a and 482b, the developing device 14 reaches the retracted position, which is the same position as in Figure 6(b). At this time, the first and second drive transmission gears 42a and 42b and the first and second drive gears 45a and 45b are in a non-contact state, which prevents the developing sleeve and transport screw from rotating due to the contact and separation movement of the developing device 14 with respect to the photosensitive drum 11.

[0054] The developing device 14 can be inserted into and removed from the image forming apparatus body 101 regardless of its position in the x-direction (left and right directions in Figures 7(a) and (b)) of the pressurized and unpressurized positions. This configuration makes it possible to insert and remove the developing device 14 without interference between the first and second drive transmission gears 42a and 42b and the first and second drive gears 45a and 45b, regardless of the position of the developing device 14.

[0055] [Arrangement of drive input section] Next, the arrangement of the first and second drive input units 451 and 452 described above will be explained using Figure 8. First, in this embodiment, when the developing device 14 is in the pressurized position and the first motor 102 is not driven, the direction in which the first drive transmission gear 42a biases the first drive gear 45a by the first spring 46a (the direction of the biasing force by the first spring 46a) is defined as the first direction, and when the developing device 14 is in the pressurized position and the second motor 103 is not driven, the direction in which the second drive transmission gear 42b biases the second drive gear 45b by the second spring 46b (the direction of the biasing force by the second spring 46b) is defined as the second direction. In this case, with respect to the straight line S connecting the rotation center of the first drive gear 45a and the rotation center of the second drive gear 45b, the first and second drive input units 451 and 452 are arranged such that the second direction has a force component in the opposite direction to the first direction.

[0056] Specifically, the first drive transmission gear 42a and the second drive transmission gear 42b are positioned on opposite sides of a straight line S connecting the rotation centers of the first drive gear 45a and the rotation centers of the second drive gear 45b. Furthermore, when the developing device 14 is in the pressurized position and the first motor 102 is driven, the biasing force by the first spring 46a is Fsa, the drive transmission force from the first drive transmission gear 42a to the first drive gear 45a is Fga, the drive transmission force from the first oscillating center gear 41a to the first drive transmission gear 42a is Fha, and the component of the resultant force in the same direction as the biasing direction by the first spring 46a is Fa. Furthermore, when the developing device 14 is in the pressurized position and the second motor 103 is driven, the biasing force by the second spring 46b is Fsb, the drive transmission force from the second drive transmission gear 42b to the second drive transmission gear 45b is Fgb, the drive transmission force from the second oscillating center gear 41b to the second drive transmission gear 42b is Fhb, and the component of these combined forces in the same direction as the biasing direction by the second spring 46b is Fb. In this case, the first drive input unit 451 and the second drive input unit 452 are arranged such that Fa and Fb cancel each other out.

[0057] Let me explain in more detail. The first and second drive transmission gears 42a and 42b move along a circle whose radius is the distance between the centers of the first and second drive transmission gears 42a and 42b and the first and second oscillating center gears 41a and 41b, respectively, and mesh with the first and second drive gears 45a and 45b. Therefore, the direction of the force Fsa due to the biasing force of the first spring 46a is perpendicular to the line (line segment Ta in Figure 8) that connects the rotation center of the first drive transmission gear 42a and the rotation center of the first oscillating center gear 41a. Also, the direction of the force Fsb due to the biasing force of the second spring 46b is perpendicular to the line (line segment Tb in Figure 8) that connects the rotation center of the second drive transmission gear 42b and the rotation center of the second oscillating center gear 41b.

[0058] When the developing device 14 is in the pressurized position and the first and second motors 102 and 103 are driven, the forces exerted by the first and second drive inputs 451 and 452 on the first and second drive gears 45a and 45b are as follows: That is, when the developing device 14 is in the pressurized position and the first and second motors 102 and 103 are driven, the forces consist of the combined forces of three components: Fsa and Fsb due to the biasing force of the first and second springs 46a and 46b; Fga and Fgb the drive transmission forces from the first and second drive transmission gears 42a and 42b to the first and second drive gears 45a and 45b; and Fha and Fhb the drive transmission forces from the first and second oscillating center gears 41a and 41b to the first and second drive transmission gears 42a and 42b.

[0059] Figure 8 shows the direction and position of each force when the developing device 14 is in the pressurized position and the first and second motors 102 and 103 are driven. The drive transmission force Fha is inclined by a pressure angle α with respect to the perpendicular line (segment Va1 in Figure 8) of the line connecting the rotation center of the first oscillating center gear 41a and the rotation center of the first drive transmission gear 42a. The drive transmission force Fhb is inclined by a pressure angle β with respect to the perpendicular line (segment Vb1 in Figure 8) of the line connecting the rotation center of the second oscillating center gear 41b and the rotation center of the second drive transmission gear 42b. The first and second drive input units 451 and 452 rotate around the first and second oscillating center gears 41a and 41b, respectively. Therefore, the actual forces that Fha and Fhb exert on the rotation axes of the first and second drive gears 45a and 45b, respectively, are Fhacosα and Fhbcosβ.

[0060] Furthermore, the drive transmission force Fga is inclined by a pressure angle α' with respect to the perpendicular line (segment Va2 in Figure 8) connecting the rotation center of the first drive transmission gear 42a and the rotation center of the first drive gear 45a. Similarly, the drive transmission force Fgb is inclined by a pressure angle β' with respect to the perpendicular line (segment Vb2 in Figure 8) connecting the rotation center of the second drive transmission gear 42b and the rotation center of the second drive gear 45b. Therefore, the actual forces exerted by Fga and Fgb on the rotation axes of the first and second drive gears 45a and 45b, respectively, are Fgasinα' and Fgbsinβ'. In this embodiment, since the tooth profiles of the first oscillating center gear 41a, the first drive transmission gear 42a, and the first drive gear 45a are identical, the pressure angles α and α' are the same value. Furthermore, in this embodiment, since the tooth profiles of the second pivot center gear 41b, the second drive transmission gear 42b, and the second drive gear 45b are identical, the pressure angle β and the pressure angle β' are the same value.

[0061] Based on this, when the developing device 14 is in the pressurized position and the first and second motors 102 and 103 are driven, the resultant force of the three forces on the first drive input unit 451 side is Fa, and the resultant force of the three forces on the second drive input unit 452 side is Fb. In this embodiment, the first drive input unit 451 and the second drive input unit 452 are arranged such that their resultant forces cancel each other out when the developing device 14 is in the pressurized position and the first and second motors 102 and 103 are driven. In particular, in this embodiment, the first and second drive transmission gears 42a and 42b are arranged so as to straddle the straight line (line segment S in Figure 8) connecting the rotation center of the first drive gear 45a and the rotation center of the second drive gear 45b.

[0062] As a result, when the developing device 14 is in the pressurized position and the first and second motors 102 and 103 are driven, the resultant force Fa acting from the first drive input 451 on the first drive gear 45a and the resultant force Fb acting from the second drive input 452 on the second drive gear 45b cancel each other out, thereby reducing the influence of the developing device 14 on the photosensitive drum 11. That is, as described above, when the developing device 14 is in the pressurized position, the first and second drive transmission gears 42a and 42b are in contact with the first and second drive gears 45a and 45b, respectively, while being biased by the first spring 46a and the second spring 46b, respectively. In this case, whether the developing device 14 is in the pressurized position and the first and second motors 102 and 103 are not driven, or whether the developing device 14 is in the pressurized position and the first and second motors 102 and 103 are driven, depending on the direction of the force acting on the first and second drive gears 45a and 45b, there is a risk that the pressure applied to the developing device 14 toward the photosensitive drum 11 may be affected. If the pressure applied to the developing device 14 is affected, there is a risk that the gap between the first developing sleeve 441 and the photosensitive drum 11, and the gap between the second developing sleeve 442 and the photosensitive drum 11, may no longer be the predetermined gap.

[0063] For example, if the direction of the force acting on the first drive gear 45a and the direction of the force acting on the second drive gear 45b are the same, the force acting on the first drive gear 45a and the force acting on the second drive gear 45b will reinforce each other. This means that the force acting on the first drive gear 45a in the direction of pressure and the force acting on the second drive gear 45b in the direction of pressure are added together with respect to the pressure applied to the developing device 14 by the pressurizing member 140. As a result, the developing device 14 is overpressurized, making it difficult to properly maintain the gap between the first and second developing sleeves 441 and 442 and the photosensitive drum 11, and there is a risk that image defects may occur due to fluctuations in this gap. In response to this, in this embodiment, the drive transmission path to the developing device 14 is first divided into two, and drive is input to the developing device 14 from two drive input units, the first drive input unit 451 and the second drive input unit 452. In addition, the first and second drive input units 451 and 452 are positioned such that the force acting from the first drive input unit 451 to the first drive gear 45a and the force acting from the second drive input unit 452 to the second drive gear 45b cancel each other out.

[0064] Therefore, even when the developing device 14 is in the pressurized position and the first and second drive transmission gears 42a and 42b are meshed with the first and second drive gears 45a and 45b, forces acting on the first and second drive gears 45a and 45b in opposing directions cancel each other out. As a result, the pressurized component of the force acting on the first drive gear 45a from the first drive input section 451 and the pressurized component of the force acting on the second drive gear 45b from the second drive input section 452 cancel each other out, thus reducing the force added to the pressurized pressure of the developing device 14 by the pressurizing member 140. In other words, the influence of the force acting on the developing device 14 due to the meshing of the first and second drive transmission gears 42a and 42b and the first and second drive gears 45a and 45b on the pressurized pressure of the developing device 14 can be reduced. Furthermore, the gap between the first and second developing sleeves 441 and 442 and the photosensitive drum 11 can be properly maintained, thereby suppressing the occurrence of image defects.

[0065] In the above description, first and second springs 46a and 46b are used as a method for biasing the first and second drive transmission gears 42a and 42b, but the method is not limited to this. Also, while a method for guiding the position of the first drive transmission gears 42a and 42b when inserting and removing the developing device, and when pressurizing and depressurizing, is used, i.e., a contact and separation mechanism using guide arms 481a and 481b, pins 49a and 49b, and guide cams 48a and 48b extending from the first and second housings 43a and 43b, the position of the first and second drive transmission gears 42a and 42b may be guided by other methods.

[0066] <Second Embodiment> The second embodiment will be described with reference to Figures 4 to 8 and with reference to Figure 9. In the above-described embodiment, a so-called twin-sleeve configuration was described in which two developing sleeves were arranged side by side. In contrast, this embodiment uses a so-called single-sleeve configuration in which the electrostatic latent image on the photosensitive drum is developed by a single developing sleeve 440. The other configurations and operations are the same as in the first embodiment described above, so the same components are denoted by the same reference numerals, and their description and illustration are omitted or simplified. The following description will focus on the parts that differ from the first embodiment.

[0067] The developing apparatus 14A of this embodiment has one developing sleeve 440 as a developer carrier. In this embodiment as well, it also has first to third transport screws 443, 444, and 447. The third transport screw 447 is positioned below the developing sleeve 440 and recovers the developer from the developing sleeve 440 and transports it by agitation. In this embodiment as well, similar to the first embodiment described above, the drive transmission unit that transmits driving force to the developing sleeve 440 and the third transport screw 47 is separate from the drive transmission unit that transmits driving force to the first transport screw 42 and the second transport screw 43.

[0068] Specifically, a driving force is input from the first drive input unit 451 to the first drive gear 45, which is driven to the developing sleeve 440 and the third transport screw 47. In addition, a driving force is input from the second drive input unit 452 to the second drive gear 45b, which is driven to the first transport screw 42 and the second transport screw 43. Furthermore, the arrangement of the first and second drive input units 451 and 452 is the same as in the first embodiment.

[0069] Specifically, even when the developing device 14A is in the pressurized position and the first and second drive transmission gears 42a and 42b are meshed with the first and second drive gears 45a and 45b, the first and second drive input units 451 and 452 are positioned such that forces acting on the first and second drive gears 45a and 45b in opposing directions cancel each other out. As a result, the force component acting from the first drive input unit 451 on the first drive gear 45a in the pressurized direction (direction from the rotation center of the developing sleeve 440 toward the rotation center of the photosensitive drum 11) and the force component acting from the second drive input unit 452 on the second drive gear 45b in the pressurized direction cancel each other out, thus reducing the force added to the pressurized pressure applied to the developing device 14A by the pressurizing member 140. Thus, in this embodiment as well, similar to the first embodiment, the gap between the developing sleeve 440 and the photosensitive drum 11 in the pressurized position can be appropriately maintained, and the occurrence of image defects can be suppressed. [Explanation of symbols]

[0070] 11. Photosensitive drum (image carrier) 14, 14A... Developing equipment 41a...First oscillating center gear 41b...Second oscillating center gear 42a...First drive transmission gear 42b...Second drive transmission gear 43a...First Housing 43b...Second Housing 45a...First drive gear 45b...Second drive gear 46a...First spring (first biasing part) 46b...Second spring (second biasing part) 110... Mounting part 410... Developing container 410a...Developing Room (Room 1) 410b... Stirring chamber (2nd chamber) 410c...Bulkhead 410d...1st communication section 410e...Second communication section 440...Developing sleeve (developer carrier) 441...First developing sleeve (first developer carrier) 442...Second developing sleeve (second developer carrier, developer carrier) 443...First conveying screw (first conveying member, conveying member) 444...Second conveying screw (second conveying component) 447...Third conveying screw (third conveying member) 451...First drive input section 452...Second drive input section

Claims

1. An image forming apparatus, Image carrier and, A developing apparatus comprising: a developing container for containing a developer; a developer carrier for carrying and transporting the developer in the developing container in order to develop the electrostatic latent image formed on the image carrier; a transport member for transporting the developer within the developing container; a first drive gear for driving the developer carrier; and a second drive gear for driving the transport member. A mounting section for attaching the developing device, The first drive transmission gear has a first drive transmission gear that meshes with the first drive gear and inputs drive to the first drive gear when the developing device is mounted on the mounting part, and a first biasing part has a first drive input part that biases the first drive transmission gear toward the first drive gear, and to which the driving force is input, The second drive transmission gear has a second drive transmission gear that meshes with the second drive gear and inputs drive to the second drive gear when the developing device is mounted on the mounting part, and a second biasing part has a second biasing part that biases the second drive transmission gear toward the second drive gear, and the second drive input part to which the driving force is input, The device includes a contact / separation mechanism that causes the first drive transmission gear and the second drive transmission gear to contact and separate from the first drive gear and the second drive gear, respectively, when the developing device is attached to or detached from the mounting section. In a state where the first drive transmission gear is in contact with the first drive gear and the second drive transmission gear is in contact with the second drive gear by the contact / separation mechanism, when no driving force is input to the first drive input, the direction in which the first biasing unit biases the first drive transmission gear is defined as the first direction, and when no driving force is input to the second drive input, the direction in which the second biasing unit biases the second drive transmission gear is defined as the second direction, the second direction has a force component opposite to that of the first direction with respect to the straight line connecting the rotation center of the first drive gear and the rotation center of the second drive gear. An image forming apparatus characterized by the following:

2. The first drive transmission gear and the second drive transmission gear are arranged on opposite sides of the straight line. The image forming apparatus according to feature 1.

3. The first drive input unit includes, in addition to the first drive transmission gear and the first biasing unit, a first pivoting center gear and a first housing that is pivotably mounted together with the first drive transmission gear around the first pivoting center gear. The first biasing unit biases the first housing so that the first drive transmission gear is directed toward the first drive gear. The second drive input unit includes, in addition to the second drive transmission gear and the second biasing unit, a second pivoting center gear and a second housing that is pivotably mounted together with the second drive transmission gear around the second pivoting center gear. The second biasing unit biases the second housing so that the second drive transmission gear is directed toward the second drive gear. The image forming apparatus according to feature 1.

4. When the contact / separation mechanism brings the first drive gear into contact with the first drive transmission gear and the second drive gear into contact with the second drive transmission gear, and when a driving force is input to the first drive input, the biasing force by the first biasing unit is Fsa, the driving force transmitted from the first drive transmission gear to the first drive gear is Fga, the driving force transmitted from the first oscillating center gear to the first drive transmission gear is Fha, and the component of the resultant force in the same direction as the biasing direction by the first biasing unit is Fa; and when a driving force is input to the second drive input, the biasing force by the second biasing unit is Fsb, the driving force transmitted from the second drive transmission gear to the second drive gear is Fgb, the driving force transmitted from the second oscillating center gear to the second drive transmission gear is Fhb, and the component of the resultant force in the same direction as the biasing direction by the second biasing unit is Fb, The first drive input unit and the second drive input unit are arranged such that Fa and Fb cancel each other out. The image forming apparatus according to feature 3.

5. The developing container has a first chamber for supplying the developer to the developer carrier, a second chamber through which the developer circulates between the first chamber and the second chamber, and a partition wall separating the first chamber and the second chamber. The developing apparatus includes a first communication section that allows the developer to move from the second chamber to the first chamber, a second communication section that allows the developer to move from the first chamber to the second chamber, a first transport member located in the first chamber that transports the developer in a first direction from the first communication section to the second communication section, a second transport member located in the second chamber that transports the developer in a second direction from the second communication section to the first communication section, and a third transport member located below the developer carrier that recovers the developer from the developer carrier and transports it while stirring. The transport member is the first transport member, The first drive gear drives the developer carrier and the third transport member, The second drive gear drives the first conveying member and the second conveying member. The image forming apparatus according to feature 1.

6. A first motor for supplying the driving force input to the first drive input unit, The system further comprises a second motor for supplying the driving force input to the second drive input section. The image forming apparatus according to any one of claims 1 to 5.

7. An image forming apparatus, Image carrier and, A developing apparatus comprising: a developing container for containing a developer; a first developer carrier for carrying and transporting the developer in the developing container in order to develop an electrostatic latent image formed on the image carrier; a second developer carrier arranged in parallel with the first developer carrier with a predetermined gap between them for carrying and transporting the developer in order to develop an electrostatic latent image formed on the image carrier; a transport member for transporting the developer within the developing container; a first drive gear for driving the first developer carrier and the second developer carrier; and a second drive gear for driving the transport member. A mounting section for attaching the developing device, The first drive transmission gear has a first drive transmission gear that meshes with the first drive gear and inputs drive to the first drive gear when the developing device is mounted on the mounting part, and a first biasing part has a first drive input part that biases the first drive transmission gear toward the first drive gear, and to which the driving force is input, The second drive transmission gear has a second drive transmission gear that meshes with the second drive gear and inputs drive to the second drive gear when the developing device is mounted on the mounting part, and a second biasing part has a second biasing part that biases the second drive transmission gear toward the second drive gear, and the second drive input part to which the driving force is input, The device includes a contact / separation mechanism that causes the first drive transmission gear and the second drive transmission gear to contact and separate from the first drive gear and the second drive gear, respectively, when the developing device is attached to or detached from the mounting section. In a state where the first drive transmission gear is in contact with the first drive gear and the second drive transmission gear is in contact with the second drive gear by the contact / separation mechanism, when no driving force is input to the first drive input, the direction in which the first biasing unit biases the first drive transmission gear is defined as the first direction, and when no driving force is input to the second drive input, the direction in which the second biasing unit biases the second drive transmission gear is defined as the second direction, the second direction has a force component opposite to that of the first direction with respect to the straight line connecting the rotation center of the first drive gear and the rotation center of the second drive gear. An image forming apparatus characterized by the following:

8. The first drive transmission gear and the second drive transmission gear are arranged on opposite sides of the straight line. The image forming apparatus according to feature 7.

9. The first drive input unit includes, in addition to the first drive transmission gear and the first biasing unit, a first pivoting center gear and a first housing that is pivotably mounted together with the first drive transmission gear around the first pivoting center gear. The first biasing unit biases the first housing so that the first drive transmission gear is directed toward the first drive gear. The second drive input unit includes, in addition to the second drive transmission gear and the second biasing unit, a second pivoting center gear and a second housing that is pivotably mounted together with the second drive transmission gear around the second pivoting center gear. The second biasing unit biases the second housing so that the second drive transmission gear is directed toward the second drive gear. The image forming apparatus according to feature 7.

10. When the contact / separation mechanism brings the first drive gear into contact with the first drive transmission gear and the second drive gear into contact with the second drive transmission gear, and when a driving force is input to the first drive input, the biasing force by the first biasing unit is Fsa, the driving force transmitted from the first drive transmission gear to the first drive gear is Fga, the driving force transmitted from the first oscillating center gear to the first drive transmission gear is Fha, and the component of the resultant force in the same direction as the biasing direction by the first biasing unit is Fa; and when a driving force is input to the second drive input, the biasing force by the second biasing unit is Fsb, the driving force transmitted from the second drive transmission gear to the second drive gear is Fgb, the driving force transmitted from the second oscillating center gear to the second drive transmission gear is Fhb, and the component of the resultant force in the same direction as the biasing direction by the second biasing unit is Fb, The first drive input unit and the second drive input unit are arranged such that Fa and Fb cancel each other out. The image forming apparatus according to feature 9.

11. The developing container has a first chamber for supplying developer to the first developer carrier, a second chamber through which the developer circulates between the first chamber and the second chamber, and a partition wall separating the first chamber and the second chamber. The developing apparatus includes a first communication section that allows the developer to move from the second chamber to the first chamber, a second communication section that allows the developer to move from the first chamber to the second chamber, a first transport member located in the first chamber that transports the developer in a first direction from the first communication section to the second communication section, a second transport member located in the second chamber that transports the developer in a second direction from the second communication section to the first communication section, and a third transport member located below the second developer carrier that recovers the developer from the second developer carrier and transports it while stirring. The transport member is the first transport member, The first drive gear drives the first developer carrier, the second developer carrier, and the third transport member. The second drive gear drives the first conveying member and the second conveying member. The image forming apparatus according to feature 7.

12. A first motor for supplying the driving force input to the first drive input unit, The system further comprises a second motor for supplying the driving force input to the second drive input section. The image forming apparatus according to any one of claims 7 to 11.

Images