Image forming apparatus

Abstract

To make uniform the distribution of toner in a developing unit, in a rotary development type image forming apparatus that can supply toner from a toner cartridge to the developing unit.SOLUTION: An image forming apparatus has developing units each receiving toner from a toner cartridge to a storage chamber through a reception port. The storage chamber is provided with a plurality of guide parts. The plurality of guide parts include a first guide part and a second guide part. In an axial direction of the rotary, the first guide part is located between the second guide part and the reception port, and the second guide part is more distant from the reception port than the first guide part. The first guide part and the second guide part are configured to guide the toner stored in the storage chamber in a direction away from the reception port in the axial direction along with the rotation of the rotary. The maximum amount of toner that can be moved in the axial direction by the second guide part along with the rotation of the rotary is smaller than the maximum amount of toner that can be moved in the axial direction by the first guide part.SELECTED DRAWING: Figure 15

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that forms an image on a recording material. [Background technology]

[0002] In electrophotographic image forming apparatuses, a rotary development system is known in which a color image is formed by rotating a rotary equipped with a plurality of developing units. Patent Documents 1 and 2 describe image forming apparatuses equipped with a rotary equipped with a plurality of developing units and a plurality of toner cartridges (toner storage containers) that are detachably attached to the rotary.

[0003] In a developing unit to which toner is supplied from a toner cartridge, toner may accumulate near the receiving port that receives toner from the toner cartridge, causing uneven distribution of toner within the developing unit and resulting in image defects such as uneven density. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-183305 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-096852 Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary development type image forming apparatus capable of supplying toner to a development unit from a toner cartridge, and to achieve a uniform distribution of toner within the development unit. [Means for solving the problem]

[0006] The present invention relates to a rotary that is rotatable around a rotation axis that extends in an axial direction; a toner cartridge supported by the rotary and having an outlet for discharging toner; a developing unit supported by the rotary, the developing unit having a receiving port for receiving the toner discharged from the discharge port, a storage chamber for storing the toner received from the receiving port, and a developing roller for carrying the toner stored in the storage chamber; In an image forming apparatus comprising: a plurality of guide portions are provided in the accommodating chamber, the plurality of guide portions including a first guide portion and a second guide portion, the first guide portion being located between the second guide portion and the receiving port in the axial direction, and the second guide portion being farther from the receiving port than the first guide portion; the first guide portion and the second guide portion are configured to guide the toner accommodated in the accommodation chamber in a direction away from the receiving opening in the axial direction as the rotary rotates, This image forming device is characterized in that the maximum amount of toner that can be moved in the axial direction by the second guide portion is less than the maximum amount of toner that can be moved in the axial direction by the first guide portion as the rotary rotates. [Effects of the Invention]

[0007] According to the present invention, in an image forming apparatus of a rotary development system in which toner can be replenished from a toner container to a developer container, the toner distribution in the developer container can be made uniform. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to an embodiment. [Figure 2] 1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment. [Figure 3] 2A and 2B are schematic diagrams of a developing unit, a toner cartridge, and a tray according to an embodiment. [Figure 4] 1A and 1B are cross-sectional views of an image forming apparatus according to an embodiment. [Figure 5]FIG. 2 is a perspective view of a rotary body according to the embodiment. [Figure 6] 1A to 1C are perspective views of an image forming apparatus according to an embodiment. [Figure 7] 1A and 1B are cross-sectional views of an image forming apparatus according to an embodiment. [Figure 8] FIG. 2 is an explanatory diagram of a rotary body according to the embodiment. [Figure 9] FIG. 2 is an explanatory diagram of a rotary body according to the embodiment. [Figure 10] FIG. 2 is an explanatory diagram of a rotary body according to the embodiment. [Figure 11] 1A and 1B are explanatory diagrams of a configuration relating to the movement of a tray in an embodiment. [Figure 12] 1A and 1B are explanatory diagrams of a configuration relating to the movement of a tray in an embodiment. [Figure 13] FIG. 2 is a diagram illustrating an internal structure of the toner cartridge according to the embodiment. [Figure 14] FIG. 2 is a cross-sectional view showing the internal structure of the toner cartridge according to the embodiment. [Figure 15] FIG. 2 is a diagram showing the internal structure of the developing unit of the first embodiment. [Figure 16] FIG. 2 is a cross-sectional view showing the internal structure of the developing unit according to the embodiment. [Figure 17] 4A and 4B are diagrams illustrating the rotation phase of the rotary assembly according to the embodiment. [Figure 18] FIG. 2 is a diagram showing a developing guide portion according to the first embodiment. [Figure 19] FIG. 10 is a diagram showing the internal structure of a developing unit according to a second embodiment. [Figure 20] FIG. 10 is a diagram showing a developing guide portion according to a second embodiment. [Figure 21] FIG. 10 is a diagram showing the internal structure of a developing unit according to a third embodiment. [Figure 22] FIG. 10 is a diagram showing a developing guide portion according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the components described in the embodiments are merely examples and are not intended to limit the scope of the present invention.

[0010] An image forming apparatus 1 according to an embodiment will be described using FIGS. 1 to 12(a), 12(b), and 17. In the following description and in each drawing, the vertical direction when the image forming apparatus 1 is installed on a horizontal surface is referred to as the Z direction. The direction intersecting the Z direction and extending in the axial direction of a rotary main body 90 (described later, the direction of the rotary's rotation axis) is referred to as the Y direction. The direction intersecting both the Z direction and the Y direction is referred to as the X direction. The X direction and the Y direction are preferably horizontal. The X direction, the Y direction, and the Z direction are preferably perpendicular to each other. Furthermore, as necessary, the directions of the arrows X, Y, and Z shown in each drawing will be referred to as the +X side, the +Y side, and the +Z side, respectively, and the opposite sides will be referred to as the -X side, the -Y side, and the -Z side, respectively.

[0011] (Overall configuration of image forming apparatus) First, we will explain the overall configuration of the image forming apparatus 1. The image forming apparatus 1 is a laser beam printer that forms an image on a sheet S by electrophotography. More specifically, the image forming apparatus 1 is a color laser beam printer equipped with four development units 50y, 50m, 50c, and 50k. As the sheet S, which is the recording material (recording medium), a variety of sheet materials of different sizes and materials can be used, including paper such as plain paper and cardboard, surface-treated sheet materials such as plastic film, cloth, and coated paper, and sheet materials of special shapes such as envelopes and index paper.

[0012] The schematic configuration and image forming operation of the image forming apparatus 1 will be described with reference to Figs. 1, 2, and 3. Fig. 1 is a schematic diagram showing the cross-sectional configuration of the image forming apparatus 1. Fig. 2 is a schematic diagram showing the cross-sectional configuration of the image forming apparatus 1. 3 is a diagram illustrating the drive source of the toner cartridge 70. FIG. 3 is a conceptual diagram showing a configuration for replenishing toner from the toner cartridge 70 to the developing unit 50.

[0013] 1, the image forming apparatus 1 includes an image forming apparatus main body (hereinafter referred to as the apparatus main body) 1A and toner cartridges 70y, 70m, 70c, and 70k that are detachably attached to the apparatus main body 1A. The apparatus main body 1A of the embodiment is the portion of the image forming apparatus 1 excluding the toner cartridges 70y, 70m, 70c, and 70k.

[0014] An apparatus main body 1A of the image forming apparatus 1 has a drum-shaped (cylindrical) electrophotographic photosensitive member (hereinafter referred to as photosensitive drum) 2 as an image carrier that carries an electrostatic latent image. Around the photosensitive drum 2, a charging roller 3, a scanner 4 as an exposure device, and a cleaning unit 6 are arranged.

[0015] The charging roller 3 is an example of a charging means or charging unit for uniformly charging the photosensitive drum 2. The scanner 4 is an example of an exposure means or exposure unit that irradiates the photosensitive drum 2 with laser light according to image information to expose it. By irradiating the charged photosensitive drum 2 with laser light, an electrostatic latent image is formed on the surface of the photosensitive drum 2. The cleaning unit 6 is an example of a cleaning means or cleaning section that removes toner remaining on the surface of the photosensitive drum 2.

[0016] Furthermore, the apparatus main body 1A has a sheet storage section 300, a pickup roller 310, a feed roller 311, a separation roller 312, a pair of conveying rollers 320, a secondary transfer roller 12, a fixing device 40, and an intermediate transfer unit 10. The pickup roller 310 is an example of a feeding means or a feeding unit that feeds the sheet S. The feed roller 311 and the separation roller 312 are examples of a separation conveying unit that separates and conveys the sheets S one by one by frictional force. The secondary transfer roller 12 is an example of a transfer means or a transfer unit that transfers an image from the intermediate transfer belt 10a to the sheet S.

[0017] The intermediate transfer unit 10 has an intermediate transfer belt 10a, a belt drive roller 10b, a tension roller 10c, a cleaning device 13, and a primary transfer roller 11. The intermediate transfer belt 10a is an example of an intermediate transfer body that carries an image transferred (primary transfer) from the photosensitive drum 2 and transports it to be transferred (secondary transfer) to a sheet S. The intermediate transfer belt 10a is stretched over the belt drive roller 10b and the tension roller 10c. The belt drive roller 10b is a drive member that is rotationally driven by a drive source to transport the intermediate transfer belt 10a.

[0018] The apparatus main body 1A also has a rotary main body (rotary, rotating body, developing device) 90 having developing units 50y, 50m, 50c, and 50k. As will be described later, in this embodiment, trays (support members) 80y, 80m, 80c, and 80k are attached to the rotary main body 90. Toner cartridges 70y, 70m, 70c, and 70k are removably attached to the trays 80y, 80m, 80c, and 80k.

[0019] In the following description, multiple components with similar functions can be distinguished by assigning numbers. For example, one of the toner cartridges 70y, 70m, 70c, and 70k can be called the first toner cartridge, one of the remaining three can be called the second toner cartridge, one of the remaining two can be called the third toner cartridge, and the last one can be called the fourth toner cartridge. Similarly, one of the trays 80y, 80m, 80c, and 80k can be called the first tray, one of the remaining three can be called the second tray, one of the remaining two can be called the third tray, and the last one can be called the fourth tray. In other words, one of the trays 80y to 80k is an example of a first support member, another of the trays 80y to 80k is an example of a second support member, yet another of the trays 80y to 80k is an example of a third support member, and the last one of the trays 80y to 80k is an example of a fourth support member. 4 is an example of a support member. These numberings are used merely for convenience of explanation, and in principle can be interchanged as appropriate.

[0020] The developing units (first to fourth developing units) 50y, 50m, 50c, and 50k are examples of developing means or developing sections that develop (visualize) the electrostatic latent image formed on the photosensitive drum 2 into a toner image using toner of the corresponding color. The developing units 50y, 50m, 50c, and 50k develop the electrostatic latent image formed on the photosensitive drum 2 using yellow toner, magenta toner, cyan toner, or black toner, respectively. The developing units 50y, 50m, 50c, and 50k may be arranged in an order different from that shown in FIG. 1.

[0021] The developing unit 50y has a developing roller 51y and a supply roller 52y. The developing roller 51y is a developer carrier that carries toner as a developer and rotates to supply the toner to the photosensitive drum 2. The supply roller 52y is disposed in contact with the developing roller 51y and is a supply member that supplies toner to the developing roller 51y. The developing blade is a regulating member that regulates the thickness of the toner layer carried by the developing roller 51y. The other developing units 50m, 50c, and 50k also have similar developing rollers 51m, 51c, and 51k, supply rollers 52m, 52c, and 52k, and developing blades.

[0022] Toner cartridges 70y, 70m, 70c, and 70k are mounted on the rotary body 90, corresponding to the developing units 50y, 50m, 50c, and 50k. The toner cartridges 70y, 70m, 70c, and 70k contain yellow toner, magenta toner, cyan toner, and black toner, respectively, to replenish the developing units 50y, 50m, 50c, and 50k. One of the four toner colors can be referred to as the first toner, one of the remaining three toner colors as the second toner, one of the remaining two toner colors as the third toner, and the last toner as the fourth toner. For example, black toner can be referred to as the first toner, and magenta toner as the second toner. These numbering schemes are used merely for convenience and can generally be interchanged as needed.

[0023] The rotary main body 90 has a rotary frame 90f that supports the developing units 50y, 50m, 50c, and 50k. The developing units 50y, 50m, 50c, and 50k are supported by the rotary frame 90f, which is a rotatable support body.

[0024] Trays 80y, 80m, 80c, and 80k are attached to the rotary body 90. The combination of the rotary body 90 and the trays 80y, 80m, 80c, and 80k can be called the rotary unit 90U. In other words, the rotary unit 90U has the rotary body 90 and the trays 80y, 80m, 80c, and 80k.

[0025] The toner cartridges 70y-70k are detachably held in the trays 80y-80k. As will be described later, the trays 80y-80k are supported so as to be slidable to the outside of the rotary main body 90. The combination of the rotary unit 90U and the toner cartridges 70y, 70m, 70c, and 70k can be referred to as the rotary assembly 90A. In other words, the rotary assembly 90A has the rotary unit 90U and the toner cartridges 70y, 70m, 70c, and 70k.

[0026] As will be described later, the rotary body 90 is rotatable around a rotation axis (rotation center) 90C. The rotation axis 90C coincides with the rotation axes of the rotary frame 90f, the rotary unit 90U, and the rotary assembly 90A. The rotation axis 90C is also substantially parallel to the rotation axis (rotation center) of the photosensitive drum 2.

[0027] The rotary body 90 is rotatable around a rotation axis 90C. By rotating around the rotation axis 90C, any one of the developing rollers 51y, 51m, 51c, and 51k can assume a developing position facing the photosensitive drum 2. The position in which the developing roller 51y faces the photosensitive drum 2 is called the yellow developing position. The position in which the developing roller 51m faces the photosensitive drum 2 is called the magenta developing position. The position in which the developing roller 51c faces the photosensitive drum 2 is called the cyan developing position. The position in which the developing roller 51k faces the photosensitive drum 2 is called the black developing position. In other words, the rotary body 90 can rotate around the rotation axis 90C so that the positions of the developing rollers 51y, 51m, 51c, and 51k relative to the photosensitive drum 2 change. The black developing position is an example of the first developing position in which the first developing roller (developing roller 51k) faces the photosensitive drum 2. The other developing positions are examples of the second developing position in which the second developing rollers (developing rollers 51y to 51c) face the photosensitive drum 2. The yellow / magenta / cyan / black developing positions can also be called the first to fourth developing positions. These numberings are used merely for convenience of explanation, and in principle can be interchanged as appropriate.

[0028] 2, the device main body 1A has motors M1, M2, and M3 as drive sources. As will be described later, the motor M1 supplies a drive force for rotating the rotary main body 90 about the rotation axis 90C. In other words, the motor M1 rotates the rotary assembly 90A and the rotary unit 90U about the rotation axis 90C.

[0029] The apparatus main body 1A also has a drive device 98 including a motor M2 and a transmission device. The transmission device includes drive racks 15L, 15R as drive gears, and a transmission unit 15t, which will be described later. The driving force of the motor M2 is transmitted to the drive racks 15L, 15R by the transmission unit 15t. In other words, the motor M2 is configured to drive the drive racks 15L, 15R, and moves the trays 80y, 80m, 80c, and 80k relative to the rotary main body 90 via the drive racks 15L, 15R.

[0030] Motor M3 drives components other than those driven by motors M1 and M2, such as the photosensitive drum 2, developing units 50y, 50m, 50c, and 50k, pickup roller 310, feed roller 311, conveying roller pair 320, secondary transfer roller 12, belt drive roller 10b, and fixing device 40.

[0031] The components driven by motors M1, M2, and M3 can be changed as needed. Also, the functions of any two or all three of motors M1, M2, and M3 can be combined into one motor. Alternatively, drive sources other than motors M1, M2, and M3 may be added.

[0032] Here, the suffixes y, m, c, and k attached to the developing units 50y, 50m, 50c, and 50k, the toner cartridges 70y, 70m, 70c, and 70k, and the trays 80y, 80m, 80c, and 80k indicate the toner colors. The developing units 50y, 50m, 50c, and 50k share the same basic configuration and function. The toner cartridges 70y, 70m, 70c, and 70k share the same basic configuration and function. The trays 80y, 80m, 80c, and 80k also share the same basic configuration and function. Therefore, when it is not necessary to distinguish between them, the suffixes y, m, c, and k are omitted, and the description will be given assuming that the unit is any one of the four units, cartridges, and trays.

[0033] 3, the toner cartridge 70 has a toner frame 71. The toner frame 71 includes a toner storage section 71a that stores toner, and an outlet 71b that communicates with the toner storage section 71a. The outlet 71b is provided on an inner surface 71d of the toner frame of the toner storage section 71a, and allows the toner inside the toner storage section 71a to be discharged.

[0034] The developing unit 50 has a developing frame (storage frame) 53. The developing frame 53 has a developing chamber 53a, a receiving port 53b communicating with the developing chamber 53a (toner supply chamber), and a developing roller The developing device includes a developing roller 51 and a supply roller 52. The receiving port 53b is provided on the inner surface 53d of the developing frame body of the developing container 53a and receives the toner discharged from the discharge port 71b. The developing container 53a receives the toner received from the receiving port 53b. The developing roller 51 carries the toner contained in the developing container 53a.

[0035] The developing roller 51k included in the developing unit 50k is an example of a first developing roller. The developing roller 51m included in the developing unit 50m is an example of a second developing roller. The developing frame 53k (FIG. 4(a)) of the developing unit 50k including the developing chamber 53a is an example of a first accommodating frame including a first accommodating portion. The developing frame 53m (FIG. 4(a)) of the developing unit 50m including the developing chamber 53a is an example of a second accommodating frame including a second accommodating portion. The rotary body 90 is an example of a rotatable rotary having a first developing roller, a second developing roller, a first accommodating frame including a first accommodating portion, and a second accommodating frame including a second accommodating portion. In the embodiment, the rotary body 90 has first to fourth developing rollers and first to fourth accommodating frames.

[0036] As will be described later, the toner cartridge 70 is movable between an attached position and a retracted position retracted from the attached position relative to the developing frame 53. When the toner cartridge 70 is in the attached position relative to the developing frame 53, the discharge opening 71b faces the receiving opening 53b. In other words, the toner storage section 71a of the toner cartridge 70 and the developer storage chamber 53a of the developing unit 50 communicate with each other via the discharge opening 71b and the receiving opening 53b. When toner is replenished from the toner cartridge 70 to the developing unit 50, at least a portion of the receiving opening 53b is positioned below at least a portion of the discharge opening 71b.

[0037] The toner contained in the toner container 71a is then discharged from the discharge port 71b, and the toner discharged from the discharge port 71b is received in the developer container 53a through the receiving port 53b. The toner contained in the developer container 53a is supplied to the developing roller 51 by the supply roller 52. The toner contained in the toner container 71a is supplied to the developing roller 51 through this route.

[0038] The toner cartridge 70 preferably has a sealing member (first sealing member) (not shown) that covers the discharge port 71b, and the developing unit 50 preferably has a sealing member (second sealing member) (not shown) that covers the receiving port 53b.

[0039] When the toner cartridge 70 is not attached to the development unit 50, it is desirable that the discharge outlet 71b and the receiving port 53b are each covered with a sealing member so as to prevent toner from flowing out from the discharge outlet 71b and the receiving port 53b.

[0040] (Image formation operation) The image forming operation in this embodiment will be described. First, the photosensitive drum 2 is rotated in the direction of the arrow (counterclockwise) in Fig. 1 in synchronization with the rotation of the intermediate transfer belt 10a. Then, the surface of the photosensitive drum 2 is uniformly charged by the charging roller 3.

[0041] When a color image is formed on the sheet S, the rotary body 90 rotates in the direction of the arrow in Figure 1 (clockwise) while supporting the developing units 50y, 50m, 50c, and 50k, as follows: Then, the electrophotographic process is repeatedly performed while the developing rollers 51y, 51m, 51c, and 51k are moved one by one to the developing position.

[0042] First, the scanner 4 irradiates the photosensitive drum 2 with laser light based on image data corresponding to a yellow image, forming an electrostatic latent image corresponding to the yellow image on the surface of the photosensitive drum 2. In parallel with the formation of this electrostatic latent image, the motor M1 rotates the rotary body 90, and the rotary body 90 assumes the yellow developing position. When the rotary body 90 assumes the yellow developing position, the developing roller 51 y is at the developing position, where the electrostatic latent image formed on the photosensitive drum 2 is developed with yellow toner.

[0043] In this embodiment, each of the developing rollers 51y, 51m, 51c, and 51k is an elastic roller having a metal shaft coated with rubber. At the developing position, each of the developing rollers 51y, 51m, 51c, and 51k develops an electrostatic latent image while in contact with the photosensitive drum 2. In other words, the image forming apparatus 1 in this embodiment employs a contact development system. However, at the developing position, each of the developing rollers 51y, 51m, 51c, and 51k may develop an electrostatic latent image while a gap is provided between the developing rollers 51y, 51m, 51c, and 51k and the photosensitive drum 2. In other words, the image forming apparatus 1 may employ a non-contact development system.

[0044] When the yellow toner image is developed, the yellow toner image on the photosensitive drum 2 is primarily transferred onto the intermediate transfer belt 10a by the primary transfer roller 11 arranged inside the intermediate transfer belt 10a.

[0045] Thereafter, the rotary body 90 is rotated to move the developing rollers 51m, 51c, and 51k to the developing positions in order, thereby forming toner images of each color. That is, after a yellow toner image is formed on the intermediate transfer belt 10a, the rotary body 90 assumes a magenta developing position, and a magenta toner image is formed on the intermediate transfer belt 10a. After a magenta toner image is formed on the intermediate transfer belt 10a, the rotary body 90 assumes a cyan developing position, and a cyan toner image is formed on the intermediate transfer belt 10a. After a cyan toner image is formed on the intermediate transfer belt 10a, the rotary body 90 assumes a black developing position, and a black toner image is formed on the intermediate transfer belt 10a. After a black toner image is formed on the intermediate transfer belt 10a, the rotary body 90 rotates around the rotation axis 90C in the direction of the arrow (clockwise) shown in FIG. 1 and returns to the yellow developing position. The color of the image formed first on the intermediate transfer belt 10a is arbitrary; for example, a black toner image may be formed first.

[0046] Then, the primary transfer is repeated so that the four color toner images are superimposed on the intermediate transfer belt 10a, thereby forming a color image on the intermediate transfer belt 10a. Note that, until the color image is formed on the intermediate transfer belt 10a, the secondary transfer roller 12 and the cleaning device 13 are not in contact with the intermediate transfer belt 10a.

[0047] Meanwhile, sheets S are fed by a pickup roller 310 from a sheet storage unit 300 provided at the bottom of the apparatus main body 1A. The sheets S are separated into individual sheets by a feed roller 311 and a separation roller 312 and then fed to a pair of conveying rollers 320. The pair of conveying rollers 320 sends the fed sheets S to a transfer unit (secondary transfer unit), which is a nip between the intermediate transfer belt 10a and the secondary transfer roller 12. The color image on the intermediate transfer belt 10a is transferred (secondary transfer) onto the surface of the conveyed sheet S.

[0048] The sheet S onto which the color image has been transferred is sent to the fixing device 40. In the fixing device 40, the sheet S is heated and pressurized, and the image is fixed onto the sheet S. After passing through the fixing device 40, the sheet S is discharged outside the image forming apparatus 1 as a finished product.

[0049] On the other hand, when a monochrome image is formed on the sheet S, the rotary body 90 takes the black developing position. In this state, an electrostatic latent image is formed on the surface of the photosensitive drum 2 by charging and exposing the photosensitive drum 2, and then the electrostatic latent image is developed with black toner by the developing roller 51k positioned at the developing position. The black toner image is primarily transferred to the intermediate transfer belt 10a, and then secondarily transferred to the sheet S. The subsequent steps are the same as those for color images.

[0050] (Rotary configuration) The configuration of the rotary body 90 will be described using Figures 1, 4(a), 4(b), and 5. Figures 4(a) and 4(b) are cross-sectional views showing the rotary body 90 and its surroundings of the image forming apparatus 1. Figures 4(a) and 4(b) are cross-sectional views of the apparatus cut along an imaginary plane perpendicular to the rotation axis 90C of the rotary body 90. Figure 5 is a perspective view of the rotary body 90.

[0051] As described above, the toner cartridges 70y to 70k are detachable from the rotary body 90. When the toner in the toner cartridges 70y to 70k runs out, the user can replenish toner in the image forming apparatus 1 by replacing the toner cartridges 70y to 70k with new ones.

[0052] 1, the device main body 1A has a frame 16 that houses the rotary main body 90. The frame 16 is the main body frame of the image forming device 1 of the embodiment. The frame 16 is the housing (skeleton) of the device main body 1A that is composed of a frame and exterior members, and is approximately rectangular in shape in the embodiment.

[0053] The frame 16 has an opening 16a. More specifically, the frame 16 has a side surface 16b that extends in a direction intersecting the horizontal direction. The side surface 16b constitutes at least a part of the exterior surface on the +X side of the device main body 1A. The opening 16a is located on this side surface 16b. The side surface 16b is located downstream of the discharge port in the discharge direction in which the sheets S on which images are formed are discharged from the discharge port of the device main body 1A. A user can access the sheet storage unit 300 from the side surface 16b of the image forming apparatus 1 to refill the sheets S or retrieve the sheets S discharged from the discharge port. Therefore, the side surface 16b can be said to be the front surface (front face) of the device main body 1A.

[0054] Toner cartridges 70y, 70m, 70c, and 70k are detachably attached to the rotary body 90 through the opening 16a. In other words, toner cartridge 70k is an example of a first toner cartridge that contains toner to be supplied to the first developing roller (developing roller 51k) and is detachably attached to the rotary (rotary body 90) through the opening 16a of the frame 16 of the apparatus main body 1A. Toner cartridge 70m is an example of a second toner cartridge that contains toner to be supplied to the second developing roller (developing roller 51m) and is detachably attached to the rotary (rotary body 90) through the opening 16a of the frame 16 of the apparatus main body 1A.

[0055] In this embodiment, the toner cartridges 70y, 70m, 70c, and 70k are supported by the trays 80y to 80k and are attached to and detached from the rotary body 90 through the opening 16a. In other words, the user can attach and detach the toner cartridges 70y to 70k to and from the rotary body 90 via the trays 80y to 80k.

[0056] The opening 16a is disposed on a side surface 16b of the frame body 16. In this embodiment, the side surface 16b is a surface that is approximately parallel to the rotation axis 90C of the rotary body 90. Therefore, when the toner cartridge 70 is replaced, the toner cartridge 70 passes through the opening 16a in a direction intersecting (preferably perpendicular to) the rotation axis 90C.

[0057] Image forming apparatus 1 has door 14 that covers opening 16a of frame 16. Door 14 is an openable / closable member that can be moved between a closed position (see also FIG. 6(a)) that covers opening 16a and an open position (see also FIGS. 6(b) and 6(c)) that exposes opening 16a.

[0058] As described above, in this embodiment, the toner cartridge 70 is configured to be detachable from the rotary body 90 via the tray 80. It can be attached and detached stably to 0.

[0059] More specifically, the user can replace the toner cartridge 70 by inserting or removing the toner cartridge 70 into or from the tray 80, which is configured to be movable relative to the rotary body 90 (i.e., relative to the device main body 1A). In a configuration in which the user replaces the toner cartridge by directly inserting or removing the toner cartridge into or from the device main body, the user is required to insert the toner cartridge to a predetermined installation position within the device main body. In the embodiment, the tray 80 is movable so that the toner cartridge 70 moves to the installation position while supporting the toner cartridge 70. Therefore, the user can replace the toner cartridge 70 by simply placing the toner cartridge 70 on the tray 80, improving operability.

[0060] The toner cartridge 70 has an elongated shape with its longitudinal direction being the Y direction parallel to the rotation axis 90C of the rotary body 90. In other words, the longitudinal dimension of the toner cartridge 70 is greater than the height and width of a cross section perpendicular to the longitudinal direction. When handling such an elongated toner cartridge 70, by locating the opening 16a on the side surface 16b of the frame 16 that is approximately parallel to the longitudinal direction (Y direction) of the toner cartridge 70, the toner cartridge 70 can pass through the opening 16a with a short movement distance. For example, this makes it easier to replace the toner cartridge 70 than when inserting or removing the toner cartridge 70 through an opening provided on the side surface of either side (+Y side or −Y side) of the frame 16 in the longitudinal direction of the toner cartridge 70.

[0061] The rotary body 90 can rotate around a rotation axis 90C and assume replacement positions that allow removal of any of the toner cartridges 70y to 70k from the rotary body 90. The position that allows removal of the toner cartridge 70y is called the yellow replacement position. The position that allows removal of the toner cartridge 70m is called the magenta replacement position. The position that allows removal of the toner cartridge 70c is called the cyan replacement position. The position that allows removal of the toner cartridge 70k is called the black replacement position. The black replacement position is an example of a first replacement position that allows removal of the first toner cartridge from the rotary body 90. The yellow / magenta / cyan replacement position is an example of a second replacement position that allows removal of the second toner cartridge from the rotary body 90. The yellow / magenta / cyan / black replacement positions can also be called the first to fourth replacement positions. These numberings are used merely for convenience of explanation and can, in principle, be interchanged as appropriate.

[0062] The rotary body 90 rotates clockwise in FIG. 1 around the rotation axis 90C, and can sequentially assume yellow, magenta, cyan, and black replacement positions. In this embodiment, the rotary body 90 alternates between the development position and the replacement position by rotating clockwise in FIG. 1 around the rotation axis 90C. For example, in FIG. 1, the rotary body 90 is in the black development position. From this state, by rotating the rotary body 90 clockwise, the rotary body 90 switches its position in the following order: cyan replacement position, yellow development position, black replacement position, magenta development position, yellow replacement position, cyan development position, and magenta replacement position. By rotating the rotary body 90 clockwise from the magenta replacement position, the rotary body 90 returns to the black development position. In other words, the rotary body 90 can rotate clockwise one revolution (360°) or more.

[0063] 4(a) shows a cross section of the rotary body 90 in a developing position (specifically, a yellow developing position), and FIG. 4(b) shows a cross section of the rotary body 90 in a replacement position (specifically, a black replacement position).

[0064] As shown in Figures 4(a) and 4(b), four trays 80y to 80k are attached to the rotary main body 90. The trays 80y to 80k hold the toner cartridges 70y to 70k, respectively. In Figures 4(a) and 4(b), the trays 80y to 80k are housed inside the rotary main body 90, which can be said to be the state in which the toner cartridges 70y to 70k are attached to the development units 50y, 50m, 50c, and 50k.

[0065] As described above, the toner cartridge 70 is movable between an attached position and a retracted position retracted from the attached position relative to the developing frame 53 of the developing unit 50. That is, the first toner cartridge (toner cartridge 70k) is movable between a first attached position and a first retracted position relative to the first accommodating frame (developing frame 53k). The second toner cartridge (toner cartridge 70m) is movable between a second attached position and a second retracted position relative to the second accommodating frame (developing frame 53m).

[0066] When the toner cartridge 70 is in the mounting position relative to the developing frame 53, the discharge port 71b and the receiving port 53b face each other, as shown in Fig. 3. In this state, the toner cartridge 70 is configured to supply toner to the developing container 53a through the receiving port 53b (the opening in the container frame).

[0067] The apparatus main body 1A has a moving device 85 configured to move the toner cartridge 70 from an attached position to a retracted position relative to the rotary main body 90 (more specifically, relative to the developing frame 53 of the developing unit 50). The moving device 85 will be described later using FIG. 8 and other figures. In this embodiment, the rotary main body 90 is provided with a plurality of moving devices 85y-85k corresponding to the plurality of toner cartridges 70y-70k. The trays 80y-80k can be said to be part of these moving devices 85y-85k.

[0068] In this embodiment, the toner cartridge 70k containing black toner is larger in size and can contain more toner than the toner cartridges 70y-70c containing yellow, magenta, and cyan toners. In other words, the first toner cartridge can contain a first amount of toner, and the second toner cartridge can contain a second amount of toner, with the first amount being greater than the second amount.

[0069] Specifically, the length of the black toner cartridge 70k in a first radial direction relative to the rotation axis 90C of the rotary body 90 is longer than the length of the magenta toner cartridge 70m in a second radial direction. Here, the first radial direction is the rotation radius direction of the rotary body 90 (the radial direction of an imaginary circle centered on the rotation axis 90C), and is the direction in which the toner cartridge 70k extends relative to the rotation axis 90C when viewed in the direction of the rotation axis 90C. The second radial direction is the rotation radius direction of the rotary body 90, and is the direction in which the toner cartridge 70m extends relative to the rotation axis 90C when viewed in the direction of the rotation axis 90C. Similarly, the length of the black toner cartridge 70k in the first radial direction is longer than the lengths of the toner cartridges 70y and 70c in the radial directions corresponding to the other toner cartridges 70y and 70c.

[0070] Therefore, the tray 80k that holds the black toner cartridge 70k is larger in size than the trays 80y-80c that hold the other toner cartridges 70y, 70m, and 70c. That is, four toner cartridges 70y-70k and trays 80y-80k of different sizes are arranged inside the rotary body 90. In other words, the rotary body 90 is detachably fitted with the toner cartridge 70k as an example of a first toner cartridge and the toner cartridge 70y as an example of a second toner cartridge that is smaller in size than the first toner cartridge. Accordingly, the rotary body 90 is detachably fitted with the toner cartridge 70k as an example of a first toner cartridge and the toner cartridge 70y as an example of a second toner cartridge that is smaller in size than the first toner cartridge. The rotary body 90 is provided with a tray 80k as an example of a first support member that supports the ridge, and a tray 80y as an example of a second support member that is smaller in size than the first support member. Furthermore, toner cartridges 70m and 70c as examples of a third toner cartridge and a fourth toner cartridge that are smaller in size than the first toner cartridge are detachably mounted on the rotary body 90. Accordingly, the rotary body 90 is provided with trays 80m and 80c as examples of a third support member and a fourth support member that are smaller in size than the first support member.

[0071] Here, the rotational drive of the rotary body 90 will be described with reference to Figure 5. As shown in Figure 5, disk gears 92L and 92R are formed at both ends of the rotary body 90. Furthermore, rotary drive gears 93L and 93R are connected to both ends of the oscillating shaft 91 so as to be capable of transmitting drive power. Here, the drive force of the motor M1 is transmitted to the rotary drive gear 93R by a drive transmission mechanism. Next, the drive force is transmitted to the disk gears 92L and 92R by the rotary drive gears 93L and 93R, thereby rotating the rotary body 90. The rotary body 90 rotates clockwise in Figure 1 around a rotation axis 90C.

[0072] The rotary body 90 is supported so as to be able to swing about a swing shaft 91. The rotary body 90 is urged by a biasing member (not shown) in the counterclockwise direction in FIGS. 4(a) and 4(b) about the swing shaft 91. This direction can be said to be the direction in which each of the developing rollers 51y to 51k approaches the photosensitive drum 2. As a result, when the rotary body 90 is in the developing position, each of the developing rollers 51y to 51k abuts against the photosensitive drum 2.

[0073] 5, rotary cams 90eL and 90eR are provided at both ends of the rotary body 90. When the rotary body 90 rotates clockwise in FIGS. 4(a) and 4(b) around the rotation axis 90C, the rotary cams 90eL and 90eR come into contact with a roller 96 (FIGS. 4(a) and 4(b)) supported by the frame 16. Then, the rotary cams 90eL and 90eR move clockwise in FIGS. 4(a) and 4(b) around the swing shaft 91. This direction can be said to be the direction in which each of the developing rollers 51y to 51k moves away from the photosensitive drum 2. This direction can also be said to be the direction in which the rotary body 90 approaches the opening 16a of the frame 16 and the door 14.

[0074] As a result, when the rotary body 90 rotates and switches from the developing position to the replacement position, the rotary body 90 swings around the swing shaft 91. When the rotary body 90 is in the replacement position, the developing roller 51 is separated from the photosensitive drum 2.

[0075] 4(b), in the black replacement position, the toner cartridge 70k stops at a position facing the opening 16a provided in the side surface 16b of the apparatus main body 1A and the door 14. From this state, when the tray 80k is slid from the attachment position to the developing unit 50k to the outside of the rotary main body 90, the user can replace the toner cartridge 70k.

[0076] (Toner cartridge replacement operation) The toner cartridge replacement operation will be described using Figures 4(a), 6(a) to 6(c), and 7(a) and 7(b). Figures 6(a) to 6(c) are external views of the device main body 1A. Figures 7(a) and 7(b) are cross-sectional views of the rotary body 90 and its surroundings when replacing the toner cartridge. Figures 7(a) and 7(b) are cross-sectional views of the device taken on an imaginary plane perpendicular to the rotation axis 90C of the rotary body 90.

[0077] 6A shows the appearance of the apparatus main body 1A during image forming operation and in a standby state. During image forming operation, the image forming apparatus 1 feeds a sheet S and forms an image on the sheet S. The standby state is a period during which a series of operations are performed, from when the image forming apparatus 1 receives an image formation instruction (print instruction) to when the image forming apparatus 1 subsequently discharges the sheet as a finished product. The standby state is a state in which the image forming apparatus 1 is ready to start an image forming operation when it receives an image formation instruction (print instruction), and is waiting for an image formation instruction from the user. As shown in FIG. 6(a), during the image forming operation and in the standby state, the door 14 is closed.

[0078] 6(b) shows the appearance of the apparatus main body 1A when replacing the toner cartridge. When replacing the toner cartridge, the door 14 is opened and the tray 80 and the toner cartridge 70 are moved to the outside of the apparatus main body 1A.

[0079] The toner cartridge 70 is movable between an attached position and a retracted position retracted from the attached position relative to the developing frame 53 of the developing unit 50. When the toner cartridge 70 is in the attached position relative to the developing frame 53, the discharge port 71b and the receiving port 53b face each other, as shown in Figure 3. As shown in Figures 4(a) and 4(b), the rotary body 90 is configured to rotate about the rotation axis 90C when the toner cartridge 70 is in the attached position, and to take a developing position or a replacement position.

[0080] The toner cartridge replacement operation will now be described. First, the user instructs the control unit of the apparatus main body 1A to perform the toner cartridge replacement operation. The instruction to perform the toner cartridge replacement operation is given, for example, by inputting via an operation panel (operation unit) provided on the apparatus main body 1A.

[0081] When the control unit receives an instruction to replace a toner cartridge, the rotary body 90 rotates to the replacement posture for the toner cartridge 70 to be replaced (the toner cartridge 70 that has run out of toner) and then stops. In other words, the control unit rotates the rotary body 90 to the replacement posture for the toner cartridge specified in the instruction to replace the toner cartridge (in FIG. 4(b) , the black replacement posture for replacing the black toner cartridge 70k). In the replacement posture, the tray 80 supporting the toner cartridge 70 instructed to be replaced faces the opening 16a of the frame 16 of the device main body 1A.

[0082] For example, the rotary body 90 in FIG. 4(a) is in a yellow developing position in which the yellow developing roller 51y faces the photosensitive drum 2. At this time, the black toner cartridge 70k and tray 80k do not have to face the opening 16a and the door 14. In other words, the toner cartridge 70 and tray 80 do not have to face the opening 16a and the door 14 when the rotary body 90 is in a replacement position other than the toner cartridge replacement position or a developing position. Therefore, the opening 16a only needs to be large enough to allow each toner cartridge 70 to pass through individually. When the rotary body 90 rotates a predetermined angle clockwise in the figure from the yellow developing position, the black toner cartridge 70k and tray 80k face the opening 16a and the door 14, as shown in FIG. 4(b).

[0083] Here, "the tray 80 faces the opening 16a" means that the tray 80 is positioned so that it can be moved to the outside of the apparatus main body 1A via the opening 16a. In other words, when the tray 80 faces the opening 16a, a moving mechanism (described later) moves the tray 80 outward in the radial direction of rotation of the rotary body 90, allowing the tray 80 and the toner cartridge 70 supported by the tray 80 to protrude to the outside of the apparatus main body 1A. In FIG. 4(a), none of the trays 80y to 80k faces the opening 16a. In FIG. 4(b), only the black tray 80k faces the opening 16a, and the other trays 80y to 80c do not face the opening 16a.

[0084] When the rotary body 90 is positioned in the replacement posture, the motor M2 moves the tray 80 supporting the toner cartridge 70 to be replaced toward the outside of the apparatus main body 1A. 6(b), 6(c), 7(a), and 7(b), the tray 80 and the toner cartridge 70 to be replaced that is supported by the tray 80 protrude to the outside of the apparatus main body 1A through the opening 16a.

[0085] More specifically, the tray 80 is movable between a storage position and an ejection position relative to the rotary body 90. The storage position is a position where the tray 80 is stored within the rotary body 90. The ejection position is a position where the tray 80 protrudes outside the rotary body 90, allowing the toner cartridge 70 to be ejected from the tray 80 (removal position, replaceable position). Examples of storage positions are the positions of the trays 80y to 80k in Figures 4(a) and 4(b). Examples of ejection positions are the positions of the tray 80 in Figures 6(b) and 6(c), the tray 80k in Figure 7(a), and the tray 80m in Figure 7(b).

[0086] When the tray 80 is in the storage position, the toner cartridge 70 attached to the tray 80 is located in the installation position. When the tray 80 is in the removal position, the toner cartridge 70 attached to the tray 80 is located in the retracted position.

[0087] As shown in Figures 7(a) and 7(b), the rotary body 90 has a protrusion 95 for holding the tray 80 in the storage position and for holding the toner cartridge 70 in the installation position. As shown in Figure 8, the tray 80 is provided with a recess 87 that fits into the protrusion 95. Figures 7(a) and 7(b) show protrusions 95k and 95m corresponding to trays 80k and 80m, and Figure 8 shows recesses 87y and 87m of trays 80y and 80m, but the protrusion 95 and recess 87 are provided for each of the trays 80y to 80k. It is preferable that the protrusion 95 is biased in a direction that engages with the recess 87.

[0088] The protrusion 95 fits into the recess 87 of the tray 80, thereby locking the tray 80 to the rotary frame body 90f. This ensures that the tray 80 remains in the storage position even when the rotary body 90 rotates, preventing the toner cartridge 70 from moving from the installation position. Note that when the tray 80 is moved between the storage position and the removal position by a moving device (described later), the protrusion 95 is moved by the tray 80, and the protrusion 95 can be configured to disengage from the recess 87.

[0089] In this embodiment, the door 14 is rotatably supported relative to the apparatus main body 1A. As shown in Fig. 7(a), the door 14 is biased from the open position toward the closed position by a spring 14s. The spring 14s is, for example, a tension spring, and biases the door 14 so as to generate a moment in the counterclockwise direction in Figs. 7(a) and 7(b) about the support shaft 14c of the door 14.

[0090] The tray 80 pushes the door 14, causing the door 14 to enter an open state (the state shown in FIG. 6(b)). This state can also be said to be a state in which the tray 80 is supported by the door 14. The door 14 supports at least a portion of the tray 80 that protrudes outside the apparatus main body 1A, thereby more stably supporting the toner cartridge 70. In other words, when the first toner cartridge (toner cartridge 70k) is in the first retracted position, the opening / closing member (door 14) in the open position supports the first support member (tray 80k). Furthermore, when the second toner cartridge (toner cartridges 70y to 70c) is in the second retracted position, the opening / closing member (door 14) in the open position supports the second support member (tray 80y to 80c).

[0091] In addition, the door 14 is configured to abut against a part of the frame 16 of the apparatus main body 1A (for example, the lower edge 16c of the opening 16a) in the open position, so as not to rotate downward beyond the open position. When the tray 80 is pulled back from the outside to the inside of the apparatus main body 1A, the biasing force of the spring 14s causes the door 14 to return to the closed position.

[0092] The toner cartridge 70 is detachably held in the tray 80. Therefore, as shown in Fig. 6(c), the user can remove the toner cartridge 70 from the tray 80 and install a new toner cartridge 70 (replacement work). When replacing multiple toner cartridges 70, the replacement work can be performed by repeating the above operation.

[0093] 7(a) and 7(b) show cross sections of the rotary body 90 and its surroundings when replacing the toner cartridge. Fig. 7(a) shows the state when replacing the black toner cartridge 70k, and Fig. 7(b) shows the state when replacing the magenta toner cartridge 70m.

[0094] The image forming apparatus 1 includes a moving device 85 (FIG. 8) that moves the toner cartridge 70 from the mounting position to the retracted position. In the embodiment, the moving device 85 can be said to include a tray 80. The moving device 85k including the tray 80k can be said to be an example of a first moving device including a first support member. The moving device 85m including the tray 80m can be said to be an example of a second moving device including a second support member.

[0095] Even when the toner cartridge 70 is in the retracted position, the tray 80 remains connected to the rotary body 90 (is supported by the rotary body 90). To easily remove the toner cartridge 70 from the rotary body 90, it is preferable that the toner cartridge 70 protrudes a long distance from the rotary body 90 when in the retracted position. Because the toner cartridge 70 is configured to be detachable from the rotary body 90 via the tray 80, the toner cartridge 70 can be stably supported by the tray 80 even when the toner cartridge 70 protrudes a long distance from the rotary body 90.

[0096] The direction in which the toner cartridge 70 moves from the mounted position to the retracted position is referred to as the retraction direction. In this embodiment, the retraction direction of the toner cartridge 70 is a direction that intersects with the direction of the rotation axis 90C (Y direction). Therefore, as shown in FIGS. 7(a) and 7(b), when viewed in the direction of the rotation axis 90C (Y direction), the retraction direction of the toner cartridge 70 is a direction that is perpendicular to the direction of the rotation axis 90C (Y direction). Furthermore, the retraction direction of the toner cartridge 70 can be said to be a direction toward the outside in the rotation radius direction of the rotary body 90 (a direction away from the rotation axis 90C).

[0097] 7(a) and 7(b), since the user removes the toner cartridge 70 from the rotary body 90, it is preferable that at least a portion of the toner cartridge 70 protrudes from the rotary body 90 when the toner cartridge 70 is removed. In this embodiment, when the toner cartridge 70 is in the retracted position, the entire toner cartridge 70 protrudes from the rotary body 90.

[0098] When the rotary body 90 rotates around the rotation axis 90C, the rotation locus of the rotary body 90 can be said to coincide with a circumscribing circle of the rotary body 90 (a virtual circle 90V shown by a dashed line in FIGS. 7(a) and 7(b)) centered on the rotation axis 90C. When the toner cartridge 70 is in the retracted position, it is preferable that more than half of the length of the toner cartridge 70 in the retracted direction is outside the rotation locus of the rotary body 90. In other words, when viewed in the direction of the rotary's rotation axis, it is preferable that, with the toner cartridge in the retracted position, more than half of the total length of the toner cartridge is located outside the rotation locus of the rotary in the direction of movement of the toner cartridge from the mounted position toward the retracted position. This applies to each toner cartridge 70, including toner cartridge 70k as an example of the first cartridge and toner cartridge 70m as an example of the second cartridge. In addition, in this embodiment, as shown in FIGS. 7(a) and 7(b), when the toner cartridge 70 is in the retracted position, The entire cartridge 70 is outside the rotation locus of the rotary body 90 (the imaginary circle 90V).

[0099] Furthermore, to make it easier for the user to grasp the toner cartridge 70, it is preferable that at least a portion of the toner cartridge 70 be outside the image forming apparatus 1 (outside the apparatus main body 1A) when the toner cartridge 70 is in the retracted position. Here, "outside the apparatus" refers to the space outside the image forming apparatus 1 (outside the apparatus main body 1A) when the image forming apparatus 1 is being used, for example, for forming an image on a sheet S.

[0100] In this embodiment, the exterior surface of the apparatus main body 1A is formed by the exterior surface of the frame 16. In other words, the outside of the apparatus can also be referred to as the outside of the frame 16. Therefore, a state in which at least a part of the toner cartridge 70 is outside the apparatus can also be referred to as a state in which at least a part of the toner cartridge 70 protrudes from the opening 16a of the frame 16 of the apparatus main body 1A toward the outside of the frame 16.

[0101] In this embodiment, when the door 14 is in the closed position, the opening 16a of the frame 16 of the apparatus main body 1A is covered by the door 14. The exterior surface 14a of the door 14 in the closed position forms part of the exterior surface of the apparatus main body 1A. In this case, the outside of the apparatus refers to the area outside the exterior surface 14a of the door 14 in the closed position. In other words, if the position of the exterior surface 14a of the door 14 in the closed position is defined as the exterior position, then when the toner cartridge 70 is in the retracted position, at least a part of the toner cartridge 70 is located outside the apparatus main body 1A beyond this exterior position.

[0102] In other words, if the door 14 were in the closed position, at least a portion of the toner cartridge 70 would be located in the space outside the apparatus main body 1A. In addition, with respect to the retraction direction of the toner cartridge 70, at least a portion of the toner cartridge 70 is located downstream of the visible position.

[0103] Furthermore, when the toner cartridge 70 is in the retracted position, with the side surface 16b on which the opening 16a is provided being the front surface of the apparatus main body 1A, at least a portion of the toner cartridge 70 protrudes forward beyond the exterior surface on the front side of the apparatus main body 1A. In this case, the user can easily access the toner cartridge 70 from the front side of the image forming apparatus and replace the toner cartridge 70.

[0104] When the toner cartridge 70 is in the retracted position, it is preferable that more than half of the toner cartridge 70's length in the retracted direction be located outside the device. In other words, when viewed in the direction of the rotary's rotation axis, when the toner cartridge is in the retracted position, it is preferable that more than half of the toner cartridge's overall length be located outside the main body frame in the direction of movement of the toner cartridge from the installed position toward the retracted position. This applies to each toner cartridge 70, including toner cartridge 70k as an example of the first cartridge and toner cartridge 70m as an example of the second cartridge. It is also preferable that the entire toner cartridge 70 be located outside the device when the toner cartridge 70 is in the retracted position. In this embodiment, the exterior surface 14a and side surface 16b of the door 14 form the exterior front surface of the device main body 1A. However, the configuration of the door 14 is not limited to this. For example, the door 14 may be large enough to cover the entire side surface 16b. In this case, the exterior surface 14a of the door 14 forms the exterior front surface of the device main body 1A.

[0105] The tray 80 has a cartridge holding portion 81 (see Figures 3 and 6(c)) that holds the toner cartridge 70. The cartridge holding portion 81 is a portion onto which the toner cartridge 70 is attached. When the tray 80 is in the removal position, it is preferable that the entire cartridge holding portion 81 is outside the rotation path of the rotary body 90 in the retraction direction. When the tray 80 is in the removal position, it is preferable that the entire cartridge holding portion 81 is outside the rotation path of the rotary body 90 in the retraction direction. Preferably, the top is outside the aircraft.

[0106] As described above, the toner cartridge 70k and the tray 80k are larger than the other toner cartridges 70y to 70c and trays 80y to 80c. Therefore, in this embodiment, as shown in Figures 7(a) and 7(b), the amount of movement of the tray 80 when replacing the toner cartridge is changed according to the size of the toner cartridge 70.

[0107] Specifically, as shown in FIG. 7(a), the movement distance of tray 80k (first support member) when it moves from the storage position (first storage position) to the removal position (first removal position) is L1. The movement distance of tray 80m (second support member) when it moves from the storage position to the removal position (third removal position) is L2. FIG. 7(b) shows the state in which toner cartridge 70m and tray 80m have moved, but the movement distance of trays 80y and 80c when they move from the storage position to the removal position is also L2. In this case, L1 is greater than L2. In other words, the movement distance of the first support member when the first toner cartridge moves from the first mounting position to the first retracted position is longer than the movement distance of the second support member when the second toner cartridge moves from the second mounting position to the second retracted position.

[0108] 7(a), when the tray 80k is in the removal position and the toner cartridge 70k is in the retracted position, the toner cartridge 70k protrudes from the exterior surface of the apparatus main body 1A by a distance P1. In this embodiment, the tray 80k also protrudes from the exterior surface of the apparatus main body 1A by a distance P1.

[0109] 7(b), when the tray 80m is in the removal position and the toner cartridge 70m is in the retracted position, the toner cartridge 70m protrudes from the exterior surface of the apparatus main body 1A by a distance P2. In this embodiment, the tray 80m also protrudes from the exterior surface of the apparatus main body 1A by a distance P2. The toner cartridges 70y and 70c also protrude from the exterior surface of the apparatus main body 1A by a distance P2.

[0110] The distance P1 is greater than the distance P2. That is, the length by which the first toner cartridge in the first retracted position protrudes from the opening 16a of the apparatus main body 1A is defined as the first length (P1), and the length by which the second toner cartridge in the second retracted position protrudes from the opening 16a is defined as the second length (P2). In this case, the first length can be said to be longer than the second length.

[0111] For toner cartridges 70y-70c, which are smaller in size than toner cartridge 70k, it is preferable from the standpoint of strength to shorten the distance P2 by which they protrude outside the apparatus when in the retracted position compared to the distance P1 by which toner cartridge 70k protrudes outside the apparatus when in the retracted position. This is for the following reason: When toner cartridge 70 is in the retracted position, at least a portion of toner cartridge 70 protrudes outside the apparatus outside the rotation path of rotary body 90 or from the external surface of apparatus main body 1A. At this time, tray 80 supports the weight of toner cartridge 70 while being cantilevered by rotary body 90. Therefore, shortening the distance P2 by which toner cartridges 70y-70c protrude outside the apparatus when in the retracted position reduces the load on trays 80y-80c and the guide portion 97 of rotary body 90 that supports trays 80y-80k. Furthermore, since the toner cartridges 70y to 70c are smaller in size than the toner cartridge 70k, even if the distance P2 is made shorter than the distance P1, the workability of replacing cartridges for the trays 80y to 80c can be maintained.

[0112] (Tray arrangement in rotary) The arrangement of the trays 80y to 80k in the rotary body 90 will be described with reference to Figures 8, 9, and 10. Figure 8 is a perspective view showing the arrangement of the trays 80y to 80k in the rotary body 90. Figure 9 is a cross-sectional view showing the arrangement of the trays 80y to 80k in the rotary body 90. 10 is a diagram showing the arrangement of components at one end of the trays 80y to 80k in the Y direction. Note that FIG. 9 shows a cross section of the rotary body 90 in an imaginary plane perpendicular to the rotation axis 90C of the rotary body 90. The upper half of FIG. 10 is a diagram showing the rotary body 90 and trays 80m and 80k of FIG. 8 as viewed from the upper right side (+Z side) of FIG. 8, and the lower half of FIG. 10 is a diagram showing the rotary body 90 and trays 80c and 80y of FIG. 8 as viewed from the left side (-X side) of FIG. 8.

[0113] 8, each of the trays 80y-80k is provided with a cartridge holding portion 81y-81k and a guided portion 82y-82k. The toner cartridges 70y-70k are attached to the cartridge holding portions 81y-81k, respectively. Each of the cartridge holding portions 81y-81k accommodates at least a portion of the toner cartridge 70y-70k attached thereto.

[0114] The guided portions 82y to 82k are provided at both ends of the trays 80y to 80k, sandwiching the cartridge holding portions 81y to 81k in the Y direction. Each of the guided portions 82y to 82k is an elongated member that extends in a direction perpendicular to the rotation axis 90C of the rotary body 90.

[0115] In the embodiment, a reinforcing rib 82k1 is formed on a portion of the guided portion 82k in the movement direction Dk of the tray 80k, and a reinforcing rib 82m1 is formed on a portion of the guided portion 82m in the movement direction Dm of the tray 80m (see also FIGS. 11(a) and 11(b)). The reinforcing ribs 82k1, 82m1 are rib-shaped (protruding stripes) that protrude outward in the Y direction from the guided portions 82k, 82m provided at both ends of the trays 80k, 80m in the Y direction and extend elongatedly in the movement directions Dk, Dm of the trays 80k, 80m. The reinforcing ribs 82k1, 82m1 improve the rigidity of the guided portions 82k, 82m.

[0116] In the embodiment, the lengths of the reinforcing ribs 82m1 and 82k1 are limited to avoid the guided portions 82y and 82c, but the reinforcing ribs 82m1 and 82k1 may be provided over the entire length of the guided portions 82m and 82k if there is no interference with the guided portions 82y and 82c. Reinforcing ribs may also be added to the guided portions 82y and 82c. Furthermore, if the rigidity of the guided portions 82m and 82k is sufficient, the reinforcing ribs 82m1 and 82k1 may not be provided.

[0117] Rack portions 83y to 83k (rack gears) are formed on the guided portions 82y to 82k. Pinion gears 94y to 94k are rotatably held within the rotary body 90. The pinion gears 94y to 94k are engaged with the rack portions 83y to 83k, respectively, so as to be capable of transmitting driving force.

[0118] The rack portions 83y-83k and pinion gears 94y-94k are part of moving devices 85y-85k configured to move the toner cartridges 70y-70k from the mounting position to the retracted position. The rack portions 83y-83k and pinion gears 94y-94k can be said to be part of a driven device that is driven by a drive device 98 of the apparatus main body 1A. The pinion gears 94y-94k can be said to be rotating bodies (rotating members) that rotate to move the trays 80y-80k relative to the rotary main body 90.

[0119] The pinion gears 94y-94k and the rack portions 83y-83k function as driven portions that allow the movement devices 85y-85k of the rotary body 90 to receive driving force from the drive device 98 of the device main body 1A. The pinion gear 94k and the rack portion 83k are an example of a first pinion gear and a first rack gear that constitute at least a part of a first driven portion provided in the first movement device. The pinion gear 94m and the rack portion 83m are an example of a second pinion gear and a second rack gear that constitute at least a part of a second driven portion provided in the second movement device.

[0120] The rotary body 90 includes guide portions 97 ( See Figures 7(a) and 7(b). Figure 7(a) shows a guide portion 97 (97k) that engages with the guided portion 82k of tray 80k, and Figure 7(b) shows a guide portion 97 (97m) that engages with the guided portion 82m of tray 80m. The rotary body 90 is provided with similar guide portions that engage with the guided portions 82y and 82c of trays 80y and 80c. Also, although Figures 7(a) and 7(b) show the guide portion 97 provided on one side (+Y side) of the rotary body 90 in the Y direction, a similar guide portion 97 is also provided on the other side (-Y side) of the rotary body 90 in the Y direction.

[0121] When tray 80 moves between the storage position and the removal position, guide portion 97 maintains an engaged state with guided portion 82 over at least a portion of the movement range, guiding movement of tray 80. In the embodiment, guide portion 97 maintains an engaged state with guided portion 82k over the entire movement range of tray 80k between the storage position and the removal position. Also, in the embodiment, guide portion 97 maintains an engaged state with guided portion 82m over the entire movement range of tray 80m between the storage position and the removal position.

[0122] As shown in FIGS. 8 and 9, four trays 80y to 80k are arranged inside the rotary body 90 so as to overlap one another, as will be described in detail below.

[0123] When the pinion gears 94y-94k rotate, the rack portions 83y-83k and the trays 80y-80k move relative to the rotary body 90. As shown in Fig. 9, the four trays 80y-80k are arranged so that their movement directions are rotated by 90 degrees relative to the rotary body 90. Therefore, the trays 80y and 80c, and the trays 80m and 80k are held so that they can slide in substantially the same direction (parallel directions). The movement direction of each of the trays 80y-80k during sliding movement is regulated by the engagement between the guided portions 82y-82k and the guide portions 97y-97k.

[0124] The trays 80y to 80k move to the outside of the apparatus through the opening 16a. When each of the trays 80y to 80k moves to the outside of the apparatus through the opening 16a, the movement directions of the respective trays are substantially the same direction (parallel).

[0125] 9, in the movement direction Dk of tray 80k, the range in which tray 80k is disposed overlaps with the range in which tray 80y and tray 80c are disposed. Furthermore, in the movement direction Dk of tray 80k, the range in which tray 80k is disposed overlaps with the rotation axis 90C of the rotary body 90. In other words, it can be said that the toner cartridge 70k held in the cartridge holding portion 81k of tray 80k overlaps with the rotation axis 90C of the rotary body 90 (FIG. 4(b)).

[0126] On the other hand, in the direction Dm of movement of tray 80m, the range in which tray 80m is arranged is shifted so as not to overlap with the range in which tray 80y is arranged and the range in which tray 80c is arranged. Furthermore, in the direction Dy of movement of tray 80y, the range in which tray 80y is arranged is shifted so as not to overlap with the range in which tray 80m is arranged and the range in which tray 80k is arranged. Similarly, in the direction Dc of movement of tray 80c, the range in which tray 80c is arranged is shifted so as not to overlap with the range in which tray 80m is arranged and the range in which tray 80k is arranged.

[0127] The positional relationship between the trays 80 can also be expressed as follows: When viewed in the movement direction Dy of the tray 80y, the tray 80y and the tray 80k overlap, but the tray 80y and the tray 80m do not overlap. When viewed in the movement direction Dm of the tray 80m, the tray 80m and the tray 80k overlap, but the tray 80m does not overlap with the trays 80y and 80c. When viewed in the movement direction Dc of the tray 80c, the tray 80c and Tray 80k overlaps, but trays 80c and 80m do not overlap.

[0128] Here, when two elements (components, parts, units, etc.) overlap when viewed in a particular direction, this means that when each element is vertically projected onto an imaginary plane perpendicular to that direction, the projection area of ​​one element at least partially overlaps with the projection area of ​​the other element.

[0129] 8 and 10, in the direction of rotation axis 90C (Y direction), the range in which rack portion 83m and guided portion 82m are arranged at least partially overlaps with the range in which rack portion 83k and guided portion 82k are arranged. That is, in the embodiment, in the direction of the rotation axis of the rotary (Y direction), the range in which the first rack gear (rack portion 83k) is arranged and the range in which the second rack gear (rack portion 83m) is arranged can be said to at least partially overlap. Therefore, compared to an arrangement in which rack portion 83m and guided portion 82m do not overlap with rack portion 83k and guided portion 82k, it is possible to arrange rack portions 83m, 83k and guided portions 82m, 82k in a less space in the Y direction.

[0130] In the direction of rotation axis 90C (Y direction), the range in which rack portion 83y and guided portion 82y are arranged at least partially overlaps with the range in which rack portion 83c and guided portion 82c are arranged. That is, in the embodiment, in the direction of the rotation axis of the rotary (Y direction), the range in which the third rack gear (rack portion 83y) is arranged at least partially overlaps with the range in which the fourth rack gear (rack portion 83c) is arranged. Therefore, compared to an arrangement in which rack portion 83y and guided portion 82y do not overlap with rack portion 83c and guided portion 82c, it is possible to arrange rack portions 83y, 83c and guided portions 82y, 82c in a less space-consuming manner in the Y direction.

[0131] Here, the meshing position between the rack portion 83 and the pinion gear 94 will be described with reference to Figure 10. The upper half of Figure 10 shows the meshing position between the rack portion 83k and the pinion gear 94k. The lower half of Figure 10 shows the meshing position between the rack portion 83y and the pinion gear 94y.

[0132] In the direction of the rotation axis 90C of the rotary body 90 (Y direction), in an area Y1 in the figure, a driving force transmitted from a motor M2 (FIG. 2) serving as a driving source by a transmission device (described later) is transmitted to the pinion gears 94y to 94k. In an area Y2 in the Y direction, the pinion gear 94k meshes with the rack portion 83k so as to be able to transmit driving force. In an area Y3 in the Y direction, the pinion gear 94y meshes with the rack portion 83y so as to be able to transmit driving force. Note that the rack portion 83m, like the rack portion 83k, meshes with the pinion gear 94m (FIG. 8) in the area Y2 so as to be able to transmit driving force. The rack portion 83c, like the rack portion 83y, meshes with the pinion gear 94c (FIG. 8) in the area Y3 so as to be able to transmit driving force.

[0133] Here, the regions Y2 and Y3 are at different positions in the Y direction (shifted in the Y direction). Also, the region Y1 is at a different position in the Y direction from both the region Y2 and the region Y3. In other words, the region Y1 is shifted in the Y direction with respect to the region Y2 and the region Y3.

[0134] Furthermore, when the toner cartridges 70y and 70c are in the mounted position, the range in which the rack portion 83y is disposed and the range in which the rack portion 83c is disposed overlap at least partially in the direction of movement of the rack portion 83y (direction of movement Dy of the tray 80y). In this embodiment, the directions of movement Dy and Dc of the trays 80y and 80c are substantially the same direction (parallel), so the range in which the rack portion 83y is disposed and the range in which the rack portion 83c is disposed also overlap at least partially in the direction of movement Dc of the tray 80c. Therefore, when the toner cartridges 70y and 70c are in the mounted position, the range in which the rack portion 83y is disposed and the range in which the rack portion 83c is disposed overlap at least partially in the direction of movement Dy and Dc of the rack portions 83y and 83c. In the direction of rotation (left and right direction in FIG. 8), the tooth surface of the rack portion 83y and the tooth surface of the rack portion 83c face each other.

[0135] Furthermore, when the toner cartridges 70m and 70k are in the installation position, the range in which the rack portion 83m is disposed at least partially overlaps with the range in which the rack portion 83k is disposed in the movement direction of the rack portion 83m (the movement direction Dm of the tray 80m). In this embodiment, the movement directions Dm and Dk of the trays 80m and 80k are substantially the same direction (parallel), so the range in which the rack portion 83m is disposed at least partially overlaps with the range in which the rack portion 83k is disposed in the movement direction Dk of the tray 80k. Therefore, when the toner cartridges 70m and 70k are in the installation position, the toothed surfaces of the rack portions 83m and 83k face each other in the direction perpendicular to the movement directions Dm and Dk of the rack portions 83m and 83k (the up-and-down direction in FIG. 8).

[0136] 12(a), when viewed in the direction of the rotation axis 90C (Y direction), rack portion 83y overlaps with rack portion 83m and rack portion 83k. When viewed in the direction of the rotation axis 90C (Y direction), rack portion 83m overlaps with rack portion 83y and rack portion 83c. When viewed in the direction of the rotation axis 90C (Y direction), rack portion 83c overlaps with rack portion 83m and rack portion 83k. When viewed in the direction of the rotation axis 90C (Y direction), rack portion 83k overlaps with rack portion 83y and rack portion 83c. In other words, in the direction of the rotation axis of the rotary (Y direction), the range in which the first rack gear (rack portion 83k) is arranged and the range in which the second rack gear (rack portion 83y) is arranged do not overlap. When viewed in the direction of the rotary's rotational axis, when the first toner cartridge 70k is in the first mounting position and the second toner cartridge 70y is in the second mounting position, the first rack gear (rack portion 83k) and the second rack gear (rack portion 83y) can be said to overlap.

[0137] In this way, since the positions at which rack sections 83k and 83m are arranged in the Y direction are different from the positions at which rack sections 83y and 83c are arranged, rack sections 83y and 83c can be arranged so that they overlap with rack sections 83m and 83k when viewed in the Y direction.

[0138] This saves space for arranging the four trays inside the rotary body 90, making it possible to reduce the size of the rotary body 90 in the direction of its rotation radius. In other words, if the rack units 83 are arranged so as not to overlap each other as viewed in the Y direction while maintaining the movement distance of each tray 80y to 80k the same as in the embodiment, the area required for arranging the four rack units as viewed in the Y direction will be larger. Compared to this configuration, by arranging the multiple rack units 83 with their positions shifted in the Y direction and making the rack units 83 overlap each other as viewed in the Y direction, it is possible to reduce the area required for arranging the rack units 83 as viewed in the Y direction.

[0139] In addition, in this embodiment, the four rack portions 83y-83k are arranged in two pairs of two, with their positions shifted in the Y direction. That is, in the direction of the rotary's rotation axis (Y direction), the ranges in which the first rack gear and the second rack gear are arranged overlap, and the ranges in which the third rack gear and the fourth rack gear are arranged overlap. Also, in the Y direction, the ranges in which the first rack gear and the second rack gear are arranged and the ranges in which the third rack gear and the fourth rack gear are arranged do not overlap. This makes it possible to reduce the size of the rotary body 90 in the Y direction compared to when each of the four rack portions 83y-83k is shifted in the Y direction.

[0140] (Tray movement configuration) 11(a), 11(b), 12(a), and 12(b), the configuration regarding the movement of the trays 80y to 80k arranged inside the rotary body 90 will be described. 11(a) and 11(b) are perspective views showing the configuration related to the movement of the tray 80k, and Fig. 12(a) and Fig. 12(b) are cross-sectional views showing the configuration related to the movement of the tray 80k.

[0141] In the embodiment, the trays 80y-80k are all driven by the driving force of the motor M2 transmitted to the pinion gears 94y-94k by drive racks 15L, 15R serving as a transmission device. Here, a configuration for moving the tray 80k relative to the rotary body 90 will be described, and a configuration for moving the trays 80y-80c relative to the rotary body 90 will not be described because it is substantially the same as the configuration for moving the tray 80k.

[0142] FIG. 11(a) shows a state in which the tray 80k is inside the rotary body 90 (i.e., a state in which the toner cartridge 70k is attached to the developing unit 50k). That is, FIG. 11(a) shows a state in which the tray 80k is in the storage position, which corresponds to a state in which the toner cartridge 70k is in the attachment position relative to the developing frame 53k (FIG. 4(a)). FIG. 11(b) shows a state in which the tray 80k has been slid to the outside of the rotary body 90. That is, FIG. 11(b) shows a state in which the tray 80k is in the removal position, which corresponds to a state in which the toner cartridge 70k is in the retracted position relative to the developing frame 53k (FIG. 4(b)).

[0143] The apparatus main body 1A of the embodiment has drive racks 15L and 15R as drive gears that drive the pinion gear 94. Each drive rack 15L is driven by a motor M2 via a drive transmission mechanism (not shown).

[0144] As described above, the rack portion 83k is formed at each end of the tray 80k in the Y direction. The pinion gear 94k and the drive racks 15L, 15R are disposed at positions corresponding to the rack portions 83k at each end. In other words, the apparatus main body 1A of the embodiment has the drive racks 15L, 15R as a first drive gear and a second drive gear. The drive rack 15L is an example of a first drive gear, and the drive rack 15R is an example of a second drive gear.

[0145] However, these numbering schemes are merely used for convenience in explanation, and in principle can be interchanged as appropriate. When there is no need to distinguish between the drive racks 15L and 15R, they will be referred to as "drive rack 15."

[0146] The rack portion 83 in the embodiment is configured as a rack gear pair, and the pinion gear 94 in the embodiment is configured as a pinion gear pair. In the embodiment, the rack gear pair and the pinion gear pair are arranged at one end side and the other end side of the support member (tray 80) in the Y direction, but they may be arranged at other positions. The rack portion 83k and the pinion gear 94k of the moving device 85k corresponding to the tray 80k can be said to be examples of the first rack gear pair and the first pinion gear pair, respectively.

[0147] The rack portions 83y to 83c and pinion gears 94y to 94c of the moving devices 85y to 85c corresponding to any of the other trays 80y to 80c can be said to be examples of the second rack gear pair and the second pinion gear pair, respectively.

[0148] One of the rack gear pair meshes with one of the pinion gear pair, and the other of the rack gear pair meshes with the other of the pinion gear pair. At least one of the pinion gear pair is driven by a drive rack 15L serving as a first drive rack. In this embodiment, both of the pinion gear pair are simultaneously driven by drive racks 15L and 15R serving as the first and second drive racks. This makes it difficult for the tray 80 to rotate, allowing for stable movement of the toner cartridge 70. Note that the tray 80 may also have one rack portion 83 and be moved by one drive rack 15 via one pinion gear 94.

[0149] The tray 80k is moved in a direction parallel to the guided portion 82k with respect to the rotary body 90 (i.e., The drive rack 15 is held so as to be slidable in a direction intersecting the movement direction Dk of the tray 80k relative to the device main body 1A. The drive rack 15 is configured to slide (reciprocate) relative to the device main body 1A in a first direction (vertical upward in this embodiment) and a second direction (vertical downward in this embodiment) opposite to the first direction. In other words, the movement direction of the drive rack 15 in this embodiment is a direction intersecting (preferably perpendicular to) both the movement direction Dk of the tray 80k and the direction of the rotation axis 90C of the rotary body 90 (Y direction).

[0150] 11(a) and 11(b), a tray movement operation for sliding the tray 80k between the storage position and the removal position will be described. The tray movement operation of the tray 80k is performed by the motor M2 (FIG. 2), a drive transmission mechanism (not shown), the drive rack 15, the pinion gear 94k, and the rack portion 83k.

[0151] First, we will explain the tray movement operation (tray extraction operation) when removing the toner cartridge 70k from the rotary body 90. Before the tray extraction operation begins, the drive rack 15 is positioned below the position where it engages with the pinion gear 94k (FIG. 11(a)). Also, as mentioned above, when replacing the toner cartridge 70k, the rotary body 90 takes the replacement posture for the toner cartridge 70k (FIG. 4(b)).

[0152] When the tray extraction operation is started, the driving force of the motor M2 causes the drive rack 15 to slide upward in the apparatus main body 1A. As the drive rack 15 moves, it engages with the pinion gear 94k, and the pinion gear 94k is rotated.

[0153] As shown in FIG. 11(b), when the pinion gear 94k is driven to rotate in the direction of the arrow in the figure, a driving force is input to the rack portion 83k that meshes with the pinion gear 94k. As a result, the tray 80k is pushed out of the apparatus and moves from the storage position to the removal position relative to the rotary body 90. At this time, the movement direction of the tray 80k is guided in a predetermined movement direction Dk by the engagement between the guided portion 82k and the guide portion 97k (FIG. 7(a)) of the rotary body 90. As a result of the tray 80k moving from the storage position to the removal position, the toner cartridge 70k is moved from the installation position to the retracted position relative to the developing unit 50k.

[0154] With the tray 80k in the removal position and the toner cartridge 70k in the retracted position, the user can attach or detach the toner cartridge 70k to or from the tray 80k.

[0155] The tray movement operation (tray pull-in operation, tray insertion operation) when attaching the toner cartridge 70 to the rotary body 90 is performed in the reverse process of the tray pull-out operation. For example, the tray pull-in operation is started by the user operating a predetermined operation unit. When the tray pull-in operation is started, the driving force of the motor M2 causes the drive rack 15 to slide downward in the device body 1A. Here, the rotation direction of the motor M2 in the tray pull-in operation is opposite to the direction in which the tray pull-out operation is performed.

[0156] 11(b), a driving force is input to the rack portion 83k that meshes with the pinion gear 94k, and the tray 80k is thereby drawn into the apparatus and moves from the removal position to the storage position relative to the rotary body 90.

[0157] The tray 80k is guided in the movement direction Dk (opposite to the arrow in FIG. 11(b)) by the engagement between the guided portion 82k and the guide portion 97k (FIG. 7(a)) of the rotary body 90. As a result of the tray 80k moving from the removal position to the storage position, the toner cartridge 70k is moved from the retracted position to the installation position relative to the developing unit 50k.

[0158] The movement of the black tray 80k and toner cartridge 70k has been described above, but the movement of the other trays 80y-80c and toner cartridges 70y-70c is also performed by a similar mechanism. That is, in the replacement posture of each toner cartridge, the drive rack 15 transmits drive to the pinion gears 94y-94c.

[0159] A drive device 98 for driving the moving device 85 provided on the rotary body 90 is constituted by a motor M2 provided on the device body 1A, a drive rack 15 (15L, 15R), and a transmission device including a drive transmission mechanism.

[0160] As described above, in the embodiment, the rotary body 90 is provided with a plurality of moving devices 85k-85y corresponding to the plurality of toner cartridges 70k-70y. The driving device 98 of the apparatus main body 1A is a common driving device that drives the plurality of moving devices 85k-85y (a plurality of driven devices) of the rotary body 90.

[0161] In addition, in the embodiment, the rotation of the rotary body 90 switches the drive target of the drive device 98. In other words, the drive device of the embodiment includes a drive rack 15 as a transmission member that transmits the driving force of the drive source. The drive device can be in a state where the transmission member is engaged with the first driven part (pinion gear 94k) so as to be able to transmit driving force, and a state where the transmission member is engaged with the second driven part (pinion gear 94m) so as to be able to transmit driving force. In addition, the drive device can be in a state where the transmission member is disengaged from the first driven part and the second driven part.

[0162] As described above, the pinion gears 94y to 94k are held by the rotary body 90. Therefore, when the rotary body 90 rotates, it is preferable that the engagement between the pinion gears 94y to 94k and the drive rack 15 is released.

[0163] Fig. 12(a) shows a state in which the tray 80k is inside the rotary body 90 (in the storage position), and Fig. 12(b) shows a state in which the tray 80k has moved outside the rotary body 90 (in the removal position).

[0164] As shown in FIG. 12(a), when the tray 80k is inside the rotary body 90, the drive rack 15 is located at the bottom inside the device main body 1A. At this time, the drive rack 15 is retracted from the pinion gear 94k. Therefore, the drive rack 15 does not interfere with the rotation of the rotary body 90, allowing the rotary body 90 to rotate. More specifically, the drive rack 15 can be retracted outside the rotation trajectory of the rotary body 90 shown by the dotted line in FIGS. 12(a) and 12(b).

[0165] As described above, by driving the motor M2 to rotate in the forward and reverse directions, the tray 80 attached to the rotary body 90 can be moved from the storage position to the removal position and from the removal position to the storage position relative to the rotary body 90. In other words, the drive device of the embodiment can not only drive each moving device of the rotary so that the toner cartridge moves from the installation position to the retracted position, but also drive each moving device so that the toner cartridge moves from the retracted position to the installation position.

[0166] As described above, in this embodiment, the movement amount of the tray 80 when replacing the toner cartridge is changed according to the size of the toner cartridge 70. Specifically, as shown in Figures 7(a) and 7(b), the movement distance L1 when the black tray 80k moves from the storage position to the removal position is longer than the movement distance L2 when the other trays 80y to 80c move from the storage positions to the removal positions.

[0167] Therefore, in the embodiment, when the toner cartridges 70y to 70k are moved from the mounting position to the retracted position, the value obtained by dividing the speed of the rack section 83k by the speed of the driving rack 15 is greater than the value obtained by dividing the speed of the rack sections 83y to 83c by the speed of the driving rack 15.

[0168] For example, as shown in FIG. 10, the pinion gear 94y is a stepped gear, and the pitch radius of the small-diameter gear 942 meshing with the rack portion 83y is smaller than the pitch radius of the large-diameter gear 941 meshing with the drive rack 15. The pinion gears 94m and 94c are also stepped gears. Meanwhile, the pinion gear 94k has the same pitch radius at the portion meshing with the drive rack 15 and the portion meshing with the rack portion 83k. In this case, the pitch radius of the pinion gear 94k can be the same as the pitch radius of the large-diameter gear 941 of the pinion gears 94y to 94c. With this configuration, even if the movement distance of the drive rack 15 is the same, the movement distance of the rack portion 83k can be made longer than the movement distances of the other rack portions 83y to 83c. In other words, the movement distance L1 when the black tray 80k moves from the storage position to the removal position can be made longer than the movement distance L2 when the other trays 80y to 80c move from the storage position to the removal position.

[0169] Furthermore, by forming the pinion gears 94y to 94c as stepped gears, the pinion gears 94y to 94k are configured to receive driving force from the same drive rack 15, but the movement distance L1 of the tray 80k can be made greater than the movement distance L2 of the other trays 80y to 80c.

[0170] Note that instead of (or in combination with) the pinion gears 94y to 94c being stepped gears, the pinion gear 94k may be a stepped gear. In this case, the portion of the pinion gear 94k that meshes with the drive rack 15 may be a small-diameter gear, and the portion of the pinion gear 94k that meshes with the rack portion 83k may be a large-diameter gear with a larger pitch circle radius than the small-diameter gear. Also, the stepped gear is an example of a speed reduction mechanism, and may be replaced with a known speed reduction mechanism that reduces the amount of movement of a member on the output side (tray 80 side) compared to the amount of movement of a member on the input side (drive source side).

[0171] Furthermore, the movement amount of the drive rack 15 when the toner cartridge 70k is moved from the mounting position to the retracted position may be greater than the movement amount of the drive rack 15 when the toner cartridges 70y to 70c are moved from the mounting position to the retracted position.

[0172] Incidentally, the shorter the distance that the toner cartridge 70 moves from the mounted position to the retracted position, the shorter the time it takes for the toner cartridge 70 to move, and the shorter the time the user has to wait for the toner cartridge 70 to move. If the amount of movement of the drive rack 15 relative to the toner cartridge 70k is configured to be greater than the amount of movement of the drive rack 15 relative to the toner cartridges 70y-70c as described above, the time the user has to wait for the toner cartridges 70y-70c to move can be shortened.

[0173] The above-described configuration allows the movement distance L1 to be longer than the movement distance L2. These configurations can also be used in combination.

[0174] Although a configuration has been described in which the driven part has a pinion gear 94 that meshes with both the driving rack 15 and the rack part 83, the driven part may also have a gear that meshes with the driving rack 15 and a gear that meshes with the rack part 83.

[0175] Furthermore, the configuration of the moving device 85 that moves the tray 80 is not limited to the so-called rack-and-pinion configuration. For example, the member corresponding to the pinion gear 94 may be replaced with a roller that rotates when driven by the motor M2, and the tray 80 may be moved by friction between the roller and the tray 80.

[0176] Furthermore, when using rollers that rotate when driven by motor M2, the rollers may be brought into contact with the toner cartridges 70. In this case, the toner cartridges 70y-70k may be attached and detached directly to the rotary body 90 without using the trays 80y-80k. In this case, the moving device 85 is formed by rollers. Furthermore, it can be said that the rotary assembly 90A has the rotary body 90 and the toner cartridges 70y-70k.

[0177] (Guide toner to the toner cartridge outlet) The toner contained in the toner container 71a is discharged from the discharge port 71b, and the toner discharged from the discharge port 71b is received in the developer container 53a through the receiving port 53b. In the following description, it is assumed that the toner cartridge 70 is attached to the rotary body 90. The configuration for discharging the toner contained in the toner container 71a from the discharge port 71b will be described below with reference to Figures 13 and 14.

[0178] Fig. 13 is a diagram showing the internal structure of the toner cartridge 70. Fig. 14 is a cross-sectional view showing the internal structure of the toner cartridge 70, specifically a cross-sectional view of the toner cartridge 70 in a direction perpendicular to the rotation axis 90C, as viewed in the Y direction.

[0179] In the following description of the toner cartridge 70, the Y direction, which is the direction of the rotation axis 90C, is referred to as the longitudinal direction. The direction of the rotary's rotation radius, which is perpendicular to the longitudinal direction, is referred to as the lateral direction. Furthermore, the direction perpendicular to the longitudinal and lateral directions of the toner cartridge 70 is referred to as the thickness direction of the toner cartridge 70.

[0180] As shown in FIG. 13, the toner frame 71 of this embodiment has multiple outlets, including a first outlet (first opening) 71bL and a second outlet (second opening) 71bR. The first outlet 71bL and the second outlet 71bR each function as an outlet 71b communicating with the toner storage section 71a. The first outlet 71bL is located at one end of the central portion 71c of the toner frame 71, between the central portion 71c and the left side surface 71eL, in the longitudinal direction. The second outlet 71bR is located at the other end of the central portion 71c of the toner frame 71, between the central portion 71c and the right side surface 71eR, in the longitudinal direction. The first outlet 71bL is closer to the left side surface 71eL than the central portion 71c, and the second outlet 71bR is closer to the right side surface 71eR than the central portion 71c.

[0181] 14, in this embodiment, the guide portion 71g is disposed on the toner frame inner surface 71d1 within the toner frame 71. That is, the base of the guide portion 71g is connected to the toner frame inner surface 71d1. The toner frame inner surface 71d1 on which the first discharge opening 71bL is formed, the toner frame inner surface 71d1 on which the second discharge opening 71bR is formed, and the toner frame inner surface 71d1 to which the guide portion 71g is connected may be discontinuous. Meanwhile, a gap is formed between the guide portion 71g and the toner frame inner surface 71d2.

[0182] In this embodiment, the toner frame 71 includes at least one left guide portion 71gL and at least one right guide portion 71gR. The left guide portion 71gL guides the toner in the longitudinal direction toward the first discharge opening 71bL, and the right guide portion 71gR guides the toner in the longitudinal direction toward the second discharge opening 71bR.

[0183] Although the left guide portion 71gL and the right guide portion 71gR guide toner in different directions, they generally have the same basic configuration and function. Therefore, in the following description, the left guide portion 71gL and the right guide portion 71gR will be referred to as guide portion 71g, and the first discharge opening 71bL and the second discharge opening 71bR will be referred to as discharge opening 71b.

[0184] Each guide portion 71g moves by its own weight in a direction intersecting the longitudinal direction (short direction). The moving toner is guided in the longitudinal direction toward the discharge port 71b.

[0185] As shown in Figures 13 and 14, the guide portion 71g has an outer end 71go and an inner end 71gi. In the short direction, the inner end 71gi is closer to the rotation axis 90c than the outer end 71go. In addition, in the longitudinal direction, the inner end 71gi is closer to the discharge port 71b than the outer end 71go. In other words, in the longitudinal direction, the outer end 71go is closer to the center portion 71c than the inner end 71gi. When viewed in a direction perpendicular to the toner frame inner surface 71d1 (thickness direction), it is preferable that the angle α formed by the longitudinal direction and a line passing through the inner end 71gi and the outer end 71go is larger than the angle of repose of the toner.

[0186] 13 and 14, the toner frame 71 has a toner storage portion 71a and an outer surface 71o and an inner surface 71i that face each other. The outer surface 71o and the inner surface 71i extend in the thickness direction and the longitudinal direction and face each other in the short direction.

[0187] In the short-side direction, the inner surface 71i is closer to the rotation axis 90c than the outer surface 71o. In the short-side direction, the outer surface 71o is located at one end of the toner containing portion 71a, and the inner surface 71i is located at the other end of the toner containing portion 71a.

[0188] 13 and 14, the toner frame 71 has a toner storage portion 71a and opposing toner frame inner surfaces 71d1 and 71d2. The toner frame inner surfaces 71d1 and 71d2 extend in a direction intersecting (preferably perpendicular to) the thickness direction and face each other in the thickness direction. In the thickness direction, the toner frame inner surface 71d1 is located at one end of the toner storage portion 71a, and the toner frame inner surface 71d2 is located at the other end of the toner storage portion 71a.

[0189] The guide portion 71g guides the toner moving from the outer end 71go to the inner end 71gi in the lateral direction toward the discharge port 71b in the longitudinal direction.

[0190] When the toner frame inner surface 71d1 receives the weight of the toner and tilts relative to the horizontal, and the tilt angle of the toner frame inner surface 71d1 relative to the horizontal exceeds a predetermined angle, the toner moves along the toner frame inner surface 71d1. At this time, the guide portion 71g guides the toner moving along the toner frame inner surface 71d1 in the longitudinal direction toward the discharge opening 71b.

[0191] On the other hand, when the toner frame inner surface 71d2 receives the weight of the toner and is tilted relative to the horizontal, and the tilt angle of the toner frame inner surface 71d2 relative to the horizontal exceeds a predetermined angle, the toner moves along the toner frame inner surface 71d2. At this time, the toner passes through the gap between the guide portion 71g and the toner frame inner surface 71d2 and moves in the short direction from one of the outer end 71go and the inner end 71gi to the other of the outer end 71go and the inner end 71gi. The toner moving through the gap between the guide portion 71g and the toner frame inner surface 71d2 moves without being guided by the guide portion 71g.

[0192] The discharge port 71b communicates with the receiving port 53b of the developing unit 50, and the toner guided by the guide portion 71g is received by the receiving port 53b through the discharge port 71b and stored in the developing container chamber 53a.

[0193] (Toner guide for the development unit) The toner contained in the toner cartridge 70 is discharged from the discharge port 71b and is received in the developer receiving chamber 53a through the receiving port 53b. A configuration for efficiently moving the toner received through the receiving port 53b in the longitudinal direction will be described.

[0194] The developing unit 50 will be described with reference to Figure 16. In the figure, the longitudinal direction, lateral direction, and thickness direction of the developing unit 50 are defined in the same way as the longitudinal direction, lateral direction, and thickness direction of the toner cartridge 70. Figure 16 is a cross-sectional view showing the internal structure of the developing unit 50, as seen from the longitudinal direction of the developing unit 50.

[0195] 16, the developing frame 53 has a developing chamber accommodating chamber 53a, which has an outer developing surface 53o and an inner developing surface 53i as inner wall surfaces that face each other. The developing chamber accommodating chamber 53a also has a developing frame inner surface 53d that is an inner wall surface that intersects with the rotation direction of the rotary body 90. In the first embodiment, the developing frame inner surface 53d is perpendicular to the rotation direction of the rotary body 90. In other words, the developing frame inner surface 53d faces the rotation direction of the rotary body 90.

[0196] The outer developer surface 53o and the inner developer surface 53i are surfaces that extend in the thickness direction and the longitudinal direction and face each other in the short-side direction. In the short-side direction, the inner developer surface 53i is closer to the rotation axis 90c than the outer developer surface 53o. In the short-side direction, the outer developer surface 53o is located at one end of the developer storage chamber 53a, and the inner developer surface 53i is located at the other end of the developer storage chamber 53a.

[0197] As shown in FIG. 16, in the first embodiment, the developing guide portion 53g is disposed on the inner surface 53d of the developing frame 53. That is, the base of the developing guide portion 53g is connected to the inner surface 53d of the developing frame 53. The developing guide portion 53g is a rib provided so as to protrude from the inner surface 53d of the developing frame 53. The receiving port 53b is also formed on the inner surface 53d of the developing frame 53. That is, the receiving port 53b is provided on the inner wall surface of the developer accommodating chamber 53a on which the developing guide portion 53g is provided. The inner surface 53d of the developing frame 53 on which the receiving port 53b is formed and the inner surface 53d of the developing frame 53 to which the developing guide portion 53g is connected may be discontinuous.

[0198] The toner contained in the developer containing chamber 53a moves in the lateral direction due to its own weight as the rotary body 90 rotates. Each developer guide portion 53g is configured to guide the toner moving in the lateral direction due to its own weight in the longitudinal direction toward the developer central portion 53c and away from the receiving port 53b.

[0199] The developing guide portion 53g has an outer developing guide end 53go and an inner developing guide end 53gi. The developing guide portion 53g is provided so as to extend in a direction inclined with respect to the axial direction (longitudinal direction). The inner developing guide end 53gi is a first end, which is one end of the developing guide portion 53g in the direction in which the developing guide portion 53g extends, and the outer developing guide end 53go is a second end, which is the other end.

[0200] In the short direction, the inner end 53gi of the developing guide is closer to the rotation axis 90c than the outer end 53go of the developing guide. In addition, in the long direction, the outer end 53go of the developing guide is farther from the receiving opening 53b than the inner end 53gi of the developing guide. In other words, in the long direction, the outer end 53go of the developing guide is closer to the central portion 53c of the developing guide than the inner end 53gi of the developing guide.

[0201] (Rotary assembly rotation and toner movement) The movement of toner accompanying the rotation of rotary assembly 90A will be described using Figure 17. The definitions of the X, Y, and Z directions in Figure 17 are the same as those in Figures 1 to 12(a) and 12(b). Figure 17 is a cross-sectional view of a virtual plane perpendicular to rotation axis 90C of rotary body 90 as viewed in the Y direction. In Figure 17, the developer surface (top surface of toner) of the toner contained inside developer containing chamber 53a or the area where toner is present is indicated by diagonal lines.

[0202] The rotary assembly 90A rotates in the direction indicated by the arrow R (clockwise in FIG. 17). FIG. 17 virtually illustrates the state of one of the developing units 50y, 50m, and 50c (e.g., developing unit 50y) at four timings (T1, T2, T3, and T4) in a single diagram. For example, the state of the developing unit 50y at timing T1 is shown in the diagram indicated by reference numeral 50(T1), and the state of the developing unit 50y at timing T2 is shown in the diagram indicated by reference numeral 50(T2). The state of the developing unit 50y at timing T3 is shown in the diagram indicated by reference numeral 50(T3), and the state of the developing unit 50y at timing T4 is shown in the diagram indicated by reference numeral 50(T4). Note that although the size of the developing unit 50k within the rotary assembly 90A is different from that of the developing units 50y, 50m, and 50c, the behavior of the toner is the same as in FIG. 15.

[0203] Position GP4 is the position of the developing unit 50 at timing T4, and is a developing position where the developing unit 50 develops the electrostatic latent image on the photosensitive drum 2. Position GP1 is the position of the developing unit 50 at timing T1 after timing T4. Position GP2 is the position of the developing unit 50 at timing T2 after timing T1. Position GP3 is the position of the developing unit 50 at timing T3 after timing T2. When the developing unit 50 rotates further in the R direction from position GP3, it returns to position GP4.

[0204] The rotary assembly 90A rotates clockwise (indicated by arrow R). When the rotary assembly 90A makes one rotation, the developing unit 50 that was at position GP1 moves to positions GP2, GP3, and GP4 in that order, and then returns to position GP1.

[0205] (Movement phase GP1~GP2) Between positions GP1 and GP2, there is a position where the inner surface 53d of the developing frame of the developing unit 50 is parallel to the X direction (horizontal direction). From this position toward position GP2, the inclination angle of the inner surface 53d of the developing frame with respect to the horizontal direction increases. In the movement phase including positions GP1 and GP2, the normal of the inner surface 53d of the developing frame has a vertically upward component. Therefore, when the inclination angle of the inner surface 53d of the developing frame with respect to the horizontal direction exceeds a predetermined angle, the toner moves on the inner surface 53d of the developing frame with respect to the horizontal direction due to gravity acting on the toner. This movement of the toner is indicated by arrow M.

[0206] At this time, the toner moving on the developing frame inner surface 53d due to its own weight comes into contact with the developing guide portion 53g provided on the developing frame inner surface 53d and moves from the developing guide inner end 53gi toward the developing guide outer end 53go. Because the developing guide outer end 53go is located closer to the developing center portion 53c than the developing guide inner end 53gi, the toner guided by the developing guide portion 53g moves in the longitudinal direction (Y direction) toward the developing center portion 53c. As a result, the toner in the developing container 53a moves toward the developing center portion 53c. In other words, the toner in the developing container 53a moves away from the receiving port 53b.

[0207] Therefore, the movement phase in which the toner in the developing unit 50 moves in the longitudinal direction toward the developing center portion 53c is included between positions GP1 and GP2. The movement phase is the first rotation phase of the rotation phase of the rotary assembly 90A in which the developing guide portion 53g guides the toner in the axial direction (longitudinal direction, Y direction) away from the receiving opening 53b.

[0208] At positions GP1 to GP2, the developer storage chamber 53a is located above the toner storage section 71a, and the inlet 53b is located above the outlet 71b, but a backflow prevention mechanism is provided to prevent the toner in the developer storage chamber 53a from flowing into the toner storage section 71a.

[0209] (Toner supply phases GP2 to GP4) The toner moves by its own weight from the discharge port 71b provided on the inner surface 71d1 of the toner frame of the toner storage portion 71a to the receiving port 53b provided on the inner surface 53d of the developing frame 53. Therefore, toner is supplied when the discharge port 71b is positioned above the receiving port 53b in the direction of gravity.

[0210] In the first embodiment, when the developing unit 50 is at position GP2, the discharge opening 71b is lower than the receiving opening 53b in the direction of gravity. Then, after the developing unit 50 rotates in the R direction and moves to position GP3 (at which point the toner frame inner surface 71d1 and the developing frame inner surface 53d are aligned in the Z direction), the discharge opening 71b is positioned above the receiving opening 53b. Thereafter, while the developing unit 50 rotates through position GP3 and moves to position GP4, the discharge opening 71b of the toner cartridge 70 is positioned above the receiving opening 53b. Therefore, during this period, toner is mainly discharged from the discharge opening 71b and supplied to the developing unit 50 (arrow S at position GP3). Then, as the developing unit 50 moves from position GP4 to position GP1, the discharge opening 71b is positioned lower than the receiving opening 53b in the direction of gravity, and toner replenishment ceases.

[0211] Therefore, the supply phase in which toner is supplied is included between positions GP2 and GP1, and the main supply phase is between positions GP2 and GP4. The supply phase is the second rotation phase of the rotary assembly 90A in which the positional relationship between the toner cartridge 70 and the developing unit 50 is such that toner can move from the discharge port 71b to the receiving port 53b.

[0212] The movement phase (between positions GP1 and GP2) includes an attachment / detachment phase, which is a rotational phase in which the toner cartridge 70 is attached to or detached from the rotary assembly 90A. In addition, the supply phase (between positions GP2 and GP4) includes a development phase, which is a rotational phase in which the developing roller 51 develops the electrostatic latent image formed on the photosensitive drum 2.

[0213] Before passing through a supply phase (between positions GP2 and GP4) in which toner is supplied to the developer storage chamber 53a, the developing unit 50 passes through a movement phase (between positions GP1 and GP2) in which toner moves in the longitudinal direction toward the development center portion 53c. In other words, when the rotary assembly 90A makes one rotation from the attachment / detachment phase, the supply phase (second rotation phase) is located after the movement phase (first rotation phase), and the development phase is located after the movement phase (first rotation phase) and after the supply phase (second rotation phase).

[0214] Therefore, when the developing unit 50 reaches position GP3, the toner in the developer accommodating chamber 53a moves in the longitudinal direction toward the developer central portion 53c and away from the vicinity of the receiving opening 53b. Therefore, a space for receiving toner from the toner cartridge 70 is secured near the receiving opening 53b. This allows toner to be efficiently received into the developer accommodating chamber 53a from the toner cartridge 70 through the receiving opening 53b.

[0215] (Shape of the development guide and amount of toner guided) When viewed in a direction perpendicular to the inner surface 53d of the developing frame, the angle formed by a line passing through the inner end 53gi and the outer end 53go of the developing guide portion 53g and the longitudinal direction (Y direction) is defined as the developing guide angle β of the developing guide portion 53g. The developing guide angle β is preferably larger than the angle of repose of the toner.

[0216] The toner guide distance is the shortest distance between the outer end 53go and a straight line parallel to the short side direction that passes through the inner end 53gi of the developing guide. The toner guide distance is the maximum distance that the toner moves in the longitudinal direction by the developing guide portion 53g toward the central developing portion 53c.

[0217] The length of the developing guide portion 53g as viewed in the thickness direction is defined as the developing guide length, which is the length of the developing guide portion 53g along the direction in which the developing guide portion 53g extends.

[0218] The height of the developing guide portion 53g projecting from the inner surface 53d of the developing frame body is defined as the developing guide height.

[0219] The maximum amount of toner that can be moved in the axial direction (longitudinal direction) by the developer guide portion 53g as the rotary body 90 rotates is defined as the toner guide amount. The longer the toner guide distance, the greater the toner guide amount. The higher the developer guide height, the greater the toner guide amount.

[0220] (Multiple development guide parts) In this embodiment, the developer accommodating chamber 53a of the developing unit 50 is provided with a plurality of developer guide portions 53g. The plurality of developer guide portions 53g include a first guide portion and a second guide portion. In the axial direction (longitudinal direction), the first guide portion is located between the second guide portion and the receiving opening 53b, and the second guide portion is farther from the receiving opening 53b than the first guide portion. In this embodiment, the second guide portion is closer to the developer central portion 53c than the first guide portion. The first guide portion and the second guide portion are configured to guide the toner accommodated in the developer accommodating chamber 53a in the axial direction (longitudinal direction) away from the receiving opening 53b as the rotary body 90 rotates. In this embodiment, the first guide portion and the second guide portion are configured to guide the toner accommodated in the developer accommodating chamber 53a toward the developer central portion 53c in the axial direction (longitudinal direction) as the rotary body 90 rotates.

[0221] The developing guide portion 53g of this embodiment is characterized in that the amount of toner guided by the second guide portion is less than the amount of toner guided by the first guide portion. Various examples for realizing this feature will be described below.

[0222] Example 1 In Example 1, the development guide length of the first guide portion and the development guide length of the second guide portion are equal to each other, and the development guide angle β of the second guide portion is greater than the development guide angle β of the first guide portion. Therefore, the toner guide distance of the second guide portion is shorter than the toner guide distance of the first guide portion, and the toner guide amount of the second guide portion is less than the toner guide amount of the first guide portion.

[0223] 15 is a view seen in the thickness direction showing the internal structure of the developing unit 50 of Example 1. As shown in Fig. 15, the developing frame 53 of Example 1 has a developer accommodating chamber 53a, a first receiving port (first opening) 53bL, and a second receiving port (second opening) 53bR.

[0224] Each of the first receiving port 53bL and the second receiving port 53bR functions as a receiving port 53b communicating with the developer containing chamber 53a.

[0225] In the longitudinal direction, the first receiving opening 53bL is located on one end side of the central developing portion 53c of the developing frame 53, and is located between the central developing portion 53c and the left developing side surface 53eL. The second receiving opening 53bR is located on the other end side of the central developing portion 53c of the developing frame 53, and is located between the central developing portion 53c and the right developing side surface 53eR.

[0226] In the first embodiment, the first receiving opening 53bL is located closer to one end (developer left side surface 53eL) than the central developing portion 53c in the axial direction (longitudinal direction). The second receiving opening 53bR is located closer to the other end (developer right side surface 53eR) than the central developing portion 53c in the axial direction (longitudinal direction).

[0227] The first receiving opening 53bL and the second receiving opening 53bR are also formed on the inner surface 53d of the developing frame body. That is, the first receiving opening 53bL and the second receiving opening 53bR are provided on the inner wall surface of the developing container accommodating chamber 53a where the developing guide portion 53g is provided. The inner surface 53d of the developing frame body where L is formed, the inner surface 53d of the developing frame body where the second receiving port 53bR is formed, and the inner surface 53d of the developing frame body to which the developing guide portion 53g is connected may be discontinuous.

[0228] The developing frame 53 of the developing unit 50 has at least one developing left guide portion 53gL and at least one developing right guide portion 53gR. The developing left guide portion 53gL and the developing right guide portion 53gR are provided on the developing frame inner surface 53d.

[0229] Although the left and right developer guide portions 53gL and 53gR guide the toner in different directions, they generally have the same basic configuration and function. Therefore, in the following description, the left and right developer guide portions 53gL and 53gR will be referred to as developer guide portions 53g, and the first and second inlets 53bL and 53bR will be referred to as inlets 53b.

[0230] The developing frame 53 is provided with six left developing guide portions 53gL-1, 53gL-2, 53gL-3, 53gL-4, 53gL-5, and 53gL-6 in order from the side closest to the left developing surface 53eL. The developing frame 53 is also provided with six right developing guide portions 53gR-1, 53gR-2, 53gR-3, 53gR-4, 53gR-5, and 53gR-6 in order from the side closest to the right developing surface 53eR.

[0231] In the longitudinal direction (axial direction), the position of at least one of the plurality of developer left guide portions 53gL and the position of the first receiving opening 53bL are arranged to at least partially overlap. In the longitudinal direction (axial direction), the position of at least one of the plurality of developer right guide portions 53gR and the position of the second receiving opening 53bR are arranged to at least partially overlap.

[0232] The left developer guide portion 53gL is configured to guide the toner received through the first inlet 53bL in the longitudinal direction away from the first inlet 53bL, i.e., toward the central developer portion 53c. The right developer guide portion 53gR is configured to guide the toner received through the second inlet 53bR in the longitudinal direction away from the second inlet 53bR, i.e., toward the central developer portion 53c.

[0233] The developer guide lengths of the multiple developer guide portions 53g are equal to one another. Meanwhile, the developer guide angle β is larger for developer guide portions 53g that are farther from the receiving port 53b in the axial direction (longitudinal direction) (closer to the developer center portion 53c). As a result, the toner guide distance 53gm is shorter for developer guide portions 53g that are farther from the receiving port 53b (closer to the developer center portion 53c) than for developer guide portions 53g that are closer to the axial end portions (developer left side surface 53eL, developer right side surface 53eR). Therefore, the toner guide amount in the longitudinal direction is smaller for developer guide portions 53g that are farther from the receiving port 53b (closer to the developer center portion 53c) than for developer guide portions 53g that are closer to the axial end portions (developer left side surface 53eL, developer right side surface 53eR).

[0234] The left development guide portions 53gL-1, 53gL-2, 53gL-3, 53gL-4, 53gL-5, and 53gL-6 have development guide angles βL-1, βL-2, βL-3, βL-4, βL-5, and βL-6, respectively, which satisfy the relationship βL-1<βL-2<βL-3<βL-4<βL-5<βL-6.

[0235] The toner guiding distances of the left development guide portions 53gL-1, 53gL-2, 53gL-3, 53gL-4, 53gL-5, and 53gL-6 are 53gmL-1, 53gmL-2, 53gmL-3, 53gmL-4, 53gmL-5, and 53gmL-6, respectively. These toner guiding distances satisfy the following relationship: 53gmL-1 > 53gmL-2 > 53gmL-3 > 53gmL-4 > 53gmL-5 > 53gmL-6.

[0236] The right developer guide portions 53gR-1, 53gR-2, 53gR-3, 53gR-4, 53gR-5, and 53gR-6 have developer guide angles βR-1, βR-2, βR-3, βR-4, βR-5, and βR-6, respectively, which satisfy the relationship βR-1<βR-2<βR-3<βR-4<βR-5<βR-6.

[0237] The toner guiding distances of the right development guide portions 53gR-1, 53gR-2, 53gR-3, 53gR-4, 53gR-5, and 53gR-6 are 53gmR-1, 53gmR-2, 53gmR-3, 53gmR-4, 53gmR-5, and 53gmR-6, respectively. These toner guiding distances satisfy the following relationship: 53gmR-1 > 53gmR-2 > 53gmR-3 > 53gmR-4 > 53gmR-5 > 53gmR-6.

[0238] Figs. 18(a) and 18(b) are diagrams showing how the toner moving within the developing unit 50 is guided by the developing guide portion 53g. The arrow M represents the moving direction of the toner. Fig. 18(a) shows the left developing guide portion 53gL-1 which has the smallest developing guide angle βL-1 among the left developing guide portions 53gL and has the longest toner guiding distance 53gmL-1. Fig. 18(b) shows the left developing guide portion 53gL-6 which has the largest developing guide angle βL-6 among the left developing guide portions 53gL and has the shortest toner guiding distance 53gmL-6.

[0239] When the toner moving on the inner surface 53d of the developing frame contacts the developing guide portion 53g, the toner moves along the developing guide portion 53g from the inner end 53gi of the developing guide toward the outer end 53go of the developing guide.

[0240] Since the developing guide angle βL-6 of the left developing guide portion 53gL-6 is larger than the developing guide angle βL-1 of the left developing guide portion 53gL-1, the toner guiding distance 53gmL-6 is shorter than the toner guiding distance 53gmL-1. That is, the left developing guide portion 53gL-6 has a shorter toner guiding distance 53gm than the left developing guide portion 53gL-1. The left developing guide portion 53gL-1 is an example of the first guide portion, and the left developing guide portion 53gL-6 is an example of the second guide portion. In Example 1, for any n < m (n, m = 1 to 6), the left developing guide portion 53gL-n is an example of the first guide portion, and the left developing guide portion 53gL-m is an example of the second guide portion. The same relationship holds for the right developing guide portion 53gR.

[0241] As shown in Figure 15, among the left developer guide portions 53gL, the developer guide angle βL-1 of the developer left guide portion 53gL-1 closest to the first receiving opening 53bL is the smallest. The closer the developer left guide portion 53gL is to the developer center portion 53c, the larger the developer guide angle β. The developer left guide portion 53gL-6 closest to the developer center portion 53c has the largest developer guide angle βL-6. As a result, the toner guide distance 53gmL-1 of the developer left guide portion 53gL-1 is the longest among the left developer guide portions 53gL. The closer the developer left guide portion 53gL is to the developer center portion 53c, the shorter the toner guide distance 53gm is. The toner guide distance 53gmL-6 of the developer left guide portion 53gL-6 closest to the developer center portion 53c is the shortest.

[0242] Similarly, of the right developer guide portions 53gR, the developer guide angle βR-1 of the developer right guide portion 53gR-1 closest to the second receiving port 53bR is the smallest. The closer the developer right guide portion 53gR is to the developer center portion 53c, the larger the developer guide angle β. The developer guide angle βR-6 of the developer right guide portion 53gR-6 closest to the developer center portion 53c is the largest. As a result, the toner guide distance 53gmR-1 of the developer right guide portion 53gR-1 is the longest among the right developer guide portions 53gR. The closer the developer right guide portion 53gR is to the developer center portion 53c, the shorter the toner guide distance 53gm. The toner guide distance 53gmR-6 of the developer right guide portion 53gR-6 closest to the developer center portion 53c is the shortest.

[0243] When the toner moving under its own weight in the developer storage chamber 53a is guided by the developer guide portion 53g, the toner guide distance 53gm of the developer guide portion 53g closer to the developer center portion 53c is shorter than the toner guide distance 53gm of the developer guide portion 53g closer to the receiving port 53b.

[0244] As described above, according to the first embodiment, the toner supplied from the toner cartridge 70 is guided by the developer guide portion 53g and moves in the longitudinal direction away from the receiving port 53b. This prevents toner from accumulating near the receiving port 53b in the developing unit 50. Furthermore, the closer the developer guide portion 53g is to the developing center portion 53c, the shorter the toner guide distance, which prevents toner from concentrating in the developing center portion 53c and causing uneven toner distribution in the developing container 53a. This makes it possible to uniformly distribute toner in the developing container 53a, thereby preventing image defects such as uneven density.

[0245] Example 2 In Example 2, the developer guide angle β of the first guide portion and the developer guide angle β of the second guide portion are equal, and the developer guide length of the second guide portion is shorter than the developer guide length of the first guide portion. Therefore, the toner guide distance of the second guide portion is shorter than the toner guide distance of the first guide portion, and the toner guide amount of the second guide portion is less than the toner guide amount of the first guide portion. In the following explanation, the same reference numerals are used for components similar to those of Example 1, and detailed explanations will be omitted.

[0246] 19 is a view showing the internal structure of the developing unit 150 of Example 2, viewed in the thickness direction. The developing frame 153 of the developing unit 150 has at least one developing left guide portion 153gL and at least one developing right guide portion 153gR. The developing left guide portion 153gL and the developing right guide portion 153gR are provided on the developing frame inner surface 153d.

[0247] The developing frame 153 is provided with six left developing guide portions 153gL-1, 153gL-2, 153gL-3, 153gL-4, 153gL-5, and 153gL-6 in order from the side closest to the left developing surface 153eL. The developing frame 153 is also provided with six right developing guide portions 153gR-1, 153gR-2, 153gR-3, 153gR-4, 153gR-5, and 153gR-6 in order from the side closest to the right developing surface 153eR.

[0248] The multiple development guide portions 53g of the development unit 50 in Example 1 have different development guide angles β depending on their longitudinal positions, whereas the multiple development guide portions 153g of the development unit 150 in Example 2 have different development guide lengths 153gt depending on their longitudinal positions.

[0249] The developer guide angles β of the multiple developer guide portions 153g are equal to each other. Meanwhile, the developer guide length 153gt is shorter for developer guide portions 153g that are farther from the receiving port 153b in the axial direction (longitudinal direction) (closer to the developer center portion 153c). As a result, the toner guide distance 153gm ​​is shorter for developer guide portions 153g that are farther from the receiving port 153b (closer to the developer center portion 153c) than for developer guide portions 153g that are closer to the axial end portions (developer left side surface 153eL, developer right side surface 153eR). Therefore, the toner guide amount in the longitudinal direction is smaller for developer guide portions 153g that are farther from the receiving port 153b (closer to the developer center portion 153c) than for developer guide portions 153g that are closer to the axial end portions (developer left side surface 153eL, developer right side surface 153eR).

[0250] In the second embodiment, as the rotary body 90 (rotary assembly 90A) rotates, toner moves from the inner developer surface 153i to the outer developer surface 153o in the short direction of the developer containing chamber 153a. When the developer guide portion 153g moves, the toner in the longitudinal direction is guided by the developer guide portion 153g in a direction away from the receiving port 153b toward the developer central portion 153c. The shapes and arrangements of the discharge port 71b and the receiving port 153b may be the same as those of the discharge port 71b and the receiving port 53b in the first embodiment.

[0251] The developing guide portion 153g is configured to guide toner moving in the lateral direction due to its own weight toward the developing center portion 153c in the longitudinal direction. The developing guide portion 153g has a developing guide outer end 153go and a developing guide inner end 153gi. In the lateral direction, the developing guide inner end 153gi is closer to the rotation axis 90c than the developing guide outer end 153go. In addition, in the longitudinal direction, the developing guide inner end 153gi is closer to the receiving opening 153b than the developing guide outer end 153go. In other words, in the longitudinal direction, the developing guide outer end 153go is closer to the developing center portion 153c than the developing guide inner end 153gi.

[0252] The development guide lengths of the left development guide portions 153gL-1, 153gL-2, 153gL-3, 153gL-4, 153gL-5, and 153gL-6 are 153gtL-1, 153gtL-2, 153gtL-3, 153gtL-4, 153gtL-5, and 153gtL-6, respectively. These development guide lengths satisfy the relationship 153gtL-1 > 153gtL-2 > 153gtL-3 > 153gtL-4 > 153gtL-5 > 153gtL-6.

[0253] The toner guiding distances of the left development guide portions 153gL-1, 153gL-2, 153gL-3, 153gL-4, 153gL-5, and 153gL-6 are 153gmL-1, 153gmL-2, 153gmL-3, 153gmL-4, 153gmL-5, and 153gmL-6, respectively. These toner guiding distances satisfy the following relationship: 153gmL-1 > 153gmL-2 > 153gmL-3 > 153gmL-4 > 153gmL-5 > 153gmL-6.

[0254] The development guide lengths of the right development guide portions 153gR-1, 153gR-2, 153gR-3, 153gR-4, 153gR-5, and 153gR-6 are 153gtR-1, 153gtR-2, 153gtR-3, 153gtR-4, 153gtR-5, and 153gtR-6, respectively. These development guide lengths satisfy the order 153gtR-1 > 153gtR-2 > 153gtR-3 > 153gtR-4 > 153gtR-5 > 153gtR-6.

[0255] The toner guiding distances of the right development guide portions 153gR-1, 153gR-2, 153gR-3, 153gR-4, 153gR-5, and 153gR-6 are 153gmR-1, 153gmR-2, 153gmR-3, 153gmR-4, 153gmR-5, and 153gmR-6, respectively. These toner guiding distances satisfy the following order: 153gmR-1 > 153gmR-2 > 153gmR-3 > 153gmR-4 > 153gmR-5 > 153gmR-6.

[0256] Figures 20(a) and 20(b) are diagrams showing how the developer guide portion 153g guides the toner moving within the developer unit 150. Arrow M indicates the direction of toner movement. Figure 20(a) shows the developer left guide portion 153gL-1, which has the longest developer guide length 153gtL-1 and the longest toner guide distance 153gmL-1 among the developer left guide portions 153gL. Figure 20(b) shows the developer left guide portion 153gL-6, which has the shortest developer guide length 153gtL-6 and the shortest toner guide distance 153gmL-6 among the developer left guide portions 153gL.

[0257] When the toner moving on the inner surface 153d of the developing frame comes into contact with the developing guide portion 153g, the toner moves along the developing guide portion 153g from the inner end 153gi of the developing guide toward the outer end 153go of the developing guide.

[0258] The developing guide angle β is the angle between the developing guide portion 153g and the inner surface 153d of the developing frame. The angle is preferably larger than the angle of repose of the toner, and is made by a straight line passing through the inner end 153gi of the developing guide and the outer end 153go of the developing guide and the longitudinal direction (Y direction).

[0259] The toner guide distance 153gm ​​is the shortest distance between a straight line parallel to the short side direction passing through the inner end 153gi of the developing guide and the outer end 153go of the developing guide. The toner guide distance 153gm ​​is the maximum distance that the toner moves in the longitudinal direction guided by the developing guide portion 153g toward the central developing portion 153c.

[0260] Assume that the developing guide angles β of the two developing guide portions 153g are equal to each other, and the developing guide lengths 153gt are different from each other. In this case, the toner guiding distance 153gm of the developing guide portion 153g with the shorter developing guide length 153gt is shorter than the toner guiding distance 153gm of the developing guide portion 153g with the longer developing guide length 153gt.

[0261] Since the developing guide length 153gtL-6 of the left developing guide portion 153gL-6 is shorter than the developing guide length 153gtL-1 of the left developing guide portion 153gL-1, the toner guiding distance 53gmL-6 is shorter than the toner guiding distance 53gmL-1. That is, the left developing guide portion 153gL-6 has a shorter toner guiding distance 153gm than the left developing guide portion 153gL-1. The left developing guide portion 153gL-1 is an example of the first guide portion, and the left developing guide portion 153gL-6 is an example of the second guide portion. In addition, in the second embodiment, for any n < m (n, m = 1 to 6), the left developing guide portion 153gL-n is an example of the first guide portion, and the left developing guide portion 153gL-m is an example of the second guide portion. The same relationship also holds for the right developing guide portion 153gR.

[0262] As shown in FIG. 19, among the left developing guide portions 153gL, the developing guide length 153gtL-1 of the left developing guide portion 153gL-1 closest to the first receiving port 153bL is the longest. The closer the left developing guide portion 153gL is to the developing central portion 153c, the shorter the developing guide length 153gt becomes. The developing guide length 153gtL-6 of the left developing guide portion 153gL-6 closest to the developing central portion 153c is the shortest. As a result, the toner guiding distance 53gmL-1 of the left developing guide portion 153gL-1 is the longest among the left developing guide portions 153gL. The toner guiding distance 153gm becomes shorter as the left developing guide portion 153gL is closer to the developing central portion 153c. The toner guiding distance 153gmL-6 of the left developing guide portion 153gL-6 closest to the developing central portion 153c is the shortest.

[0263] Similarly, of the right developer guide portions 153gR, the developer guide length 153gtR-1 of the developer right guide portion 153gR-1 closest to the second receiving port 153bR is the longest. The closer the developer right guide portion 153gR is to the developer center portion 153c, the shorter the developer guide length 153gt. The developer guide length 153gtR-6 of the developer right guide portion 153gR-6 closest to the developer center portion 153c is the shortest. As a result, the toner guide distance 53gmR-1 of the developer right guide portion 153gR-1 is the longest among the right developer guide portions 153gR. The closer the developer right guide portion 153gR is to the developer center portion 153c, the shorter the toner guide distance 153gm. The developer right guide portion 153gR-6 closest to the developer center portion 153c is the shortest toner guide distance 153gmR-6.

[0264] Toner moving due to its own weight in the developer accommodating chamber 153a is guided by the developer guide portion 153g. In this case, the toner guide distance 153gm ​​of the developer guide portion 153g closer to the developer central portion 153c is shorter than the toner guide distance 153gm ​​of the developer guide portion 153g closer to the receiving port 153b.

[0265] As described above, according to the second embodiment, the toner supplied from the toner cartridge 70 is guided by the developing guide portion 153g and moves away from the receiving opening 153b in the longitudinal direction. Therefore, it is possible to prevent toner from accumulating near the receiving port 153b in the developing unit 150. Furthermore, since the toner guiding distance of the developing guide portion 153g becomes shorter as it is closer to the developing center portion 153c, it is possible to prevent toner from concentrating at the developing center portion 153c and causing uneven toner distribution in the developing container 153a. Therefore, it is possible to make the toner distribution in the developing container 153a uniform, and to prevent image defects such as uneven density.

[0266] In the second embodiment, the shape of the receiving opening 153b is the same as that of the receiving opening 53b in the first embodiment. The first receiving opening 153bL and at least one left developing device guide portion 153gL are disposed on the inner surface 153d of the developing device frame so as to overlap at least partially in the longitudinal direction. The second receiving opening 153bR and at least one right developing device guide portion 153gR are disposed on the inner surface 153d of the developing device frame so as to overlap at least partially in the longitudinal direction.

[0267] While the above description illustrates an example in which the left and right developer guide portions 153gL and 153gL each include six developer guide portions, the number of developer guide portions is not limited to six, as long as there are multiple developer guide portions. While the above description illustrates an example in which the developer guide lengths of the multiple developer guide portions are all different from each other, some of the multiple developer guide portions may have the same developer guide length. In this case, it is sufficient that there is a pair of developer guide portions among the multiple developer guide portions that satisfy the condition that one developer guide portion located farther from the receiving inlet has a shorter developer guide length than the other developer guide portion. It is also preferable that there is no pair of developer guide portions among the multiple developer guide portions that satisfy the condition that one developer guide portion located farther from the receiving inlet has a longer developer guide length than the other developer guide portion.

[0268] Example 3 In Example 3, the developer guide angle β of the first guide portion and the developer guide angle β of the second guide portion are equal, and the developer guide length of the first guide portion and the developer guide length of the second guide portion are equal. Meanwhile, the developer guide height of the second guide portion is lower than the developer guide height of the first guide portion. Therefore, the toner guide distance of the first guide portion and the toner guide distance of the second guide portion are equal, but the toner guide amount of the second guide portion is less than the toner guide amount of the first guide portion. In the following explanation, the same reference numerals are used for the same components as in Example 1, and detailed explanations will be omitted.

[0269] 21 is a view showing the internal structure of the developing unit 250 of Example 3, as viewed in the thickness direction. The developing frame 253 of the developing unit 250 has at least one developing left guide portion 253gL and at least one developing right guide portion 253gR. The developing left guide portion 253gL and the developing right guide portion 253gR are provided on the developing frame inner surface 253d.

[0270] The developing frame 253 is provided with six left developing guide portions 253gL-1, 253gL-2, 253gL-3, 253gL-4, 253gL-5, and 253gL-6 in order from the side closest to the left developing surface 253eL. The developing frame 253 is also provided with six right developing guide portions 253gR-1, 253gR-2, 253gR-3, 253gR-4, 253gR-5, and 253gR-6 in order from the side closest to the right developing surface 253eR.

[0271] The multiple development guide portions 53g of the development unit 50 in Example 1 have different development guide angles β depending on their longitudinal positions, whereas the multiple development guide portions 253g of the development unit 250 in Example 3 have different development guide heights 253gh depending on their longitudinal positions.

[0272] The developer guide angles β and developer guide lengths 253gt of the multiple developer guide portions 253g are equal to each other. Therefore, the toner guide distances 253gm in the longitudinal direction of the multiple developer guide portions 253g are equal to each other. On the other hand, the developer guide heights 253gh in the thickness direction are lower for developer guide portions 253g that are farther from the receiving opening 253b in the axial direction (longitudinal direction) (closer to the developer center portion 253c). As a result, the amount of toner guided in the longitudinal direction is less in the developer guide portion 253g farther from the receiving opening 253b (closer to the developer center portion 253c) than in the developer guide portion 253g close to the ends (developer left side surface 253eL, developer right side surface 253eR) in the axial direction (longitudinal direction).

[0273] In the third embodiment as well, as the rotary body 90 (rotary assembly 90A) rotates, toner moves from the inner developer surface 253i toward the outer developer surface 253o in the short direction of the developer storage chamber 253a. When the toner moves from the inner developer surface 253i to the outer developer surface 253o, the toner is guided by the developer guide portion 253g in the longitudinal direction away from the receiving port 253b. The shapes and arrangements of the discharge port 71b and the receiving port 253b may be the same as those of the discharge port 71b and the receiving port 53b in the first embodiment.

[0274] The developing guide portion 253g is configured to guide toner moving in the lateral direction due to its own weight toward the developing center portion 253c in the longitudinal direction. The developing guide portion 253g has a developing guide outer end 253go and a developing guide inner end 253gi. In the lateral direction, the developing guide inner end 253gi is closer to the rotation axis 90c than the developing guide outer end 253go. In addition, in the longitudinal direction, the developing guide inner end 253gi is closer to the receiving opening 253b than the developing guide outer end 253go. In other words, in the longitudinal direction, the developing guide outer end 253go is closer to the developing center portion 253c than the developing guide inner end 253gi.

[0275] The development guide heights of the left development guide portions 253gL-1, 253gL-2, 253gL-3, 253gL-4, 253gL-5, and 253gL-6 are 253ghL-1, 253ghL-2, 253ghL-3, 253ghL-4, 253ghL-5, and 253ghL-6, respectively. These development guide heights satisfy >253ghL-1>253ghL-2>253ghL-3>253ghL-4>253ghL-5>253ghL-6.

[0276] The development guide heights of the development right guide portions 253gR-1, 253gR-2, 253gR-3, 253gR-4, 253gR-5, and 253gR-6 are 253ghR-1, 253ghR-2, 253ghR-3, 253ghR-4, 253ghR-5, and 253ghR-6, respectively. These development guide heights satisfy >253ghR-1>253ghR-2>253ghR-3>253ghR-4>253ghR-5>253ghR-6.

[0277] Figures 22(a) and 22(b) are diagrams showing how the developer guide portion 253g guides the toner as it moves within the developer unit 250. Arrow M indicates the direction of toner movement. Figure 22(a) shows the developer left guide portion 253gL-1, which has the highest developer guide height 253ghL-1 and guides the most toner among the developer left guide portions 253gL. Figure 22(b) shows the developer left guide portion 253gL-6, which has the lowest developer guide height 253ghL-6 and guides the least toner among the developer left guide portions 253gL.

[0278] When the toner moving on the inner surface 253d of the developing frame comes into contact with the developing guide portion 253g, the toner moves along the developing guide portion 253g from the inner end 253gi of the developing guide toward the outer end 253go of the developing guide.

[0279] The developer guide height 253gh represents the height in the thickness direction of the developer guide portion 253g. Assume that the developer guide angle β and developer guide length 253gt of the two developer guide portions 253g are equal to each other, but the developer guide heights 253gh are different from each other. In this case, the amount of toner guided by the developer guide portion 253g with the lower developer guide height 253gh is less than the amount of toner guided by the developer guide portion 253g with the higher developer guide height 253gh.

[0280] The development guide height 253ghL-6 of the development left guide portion 253gL-6 is lower than the development guide height 253ghL-1 of the development left guide portion 253gL-1. The toner guiding amount of the guide portion 253gL-6 is less than that of the left developing guide portion 253gL-1. The left developing guide portion 253gL-1 is an example of the first guide portion, and the left developing guide portion 253gL-6 is an example of the second guide portion. In Example 3, for any n < m (n, m = 1 to 6), the left developing guide portion 253gL-n is an example of the first guide portion, and the left developing guide portion 253gL-m is an example of the second guide portion. The same relationship also holds for the right developing guide portion 253gR.

[0281] As shown in FIG. 21, among the left developing guide portions 253gL, the developing guide height 253ghL-1 of the left developing guide portion 253gL-1 closest to the first receiving port 253bL is the highest. The closer the left developing guide portion 253gL is to the developing central portion 253c, the lower the developing guide height 253gh. The developing guide height 253ghL-6 of the left developing guide portion 253gL-6 closest to the developing central portion 253c is the lowest. As a result, the toner guiding amount of the left developing guide portion 253gL-1 is the largest among the left developing guide portions 253gL. The toner guiding amount decreases as the left developing guide portion 253gL gets closer to the developing central portion 253c. The toner guiding amount of the left developing guide portion 253gL-6 closest to the developing central portion 253c is the smallest. <0​​​​​​When the toner moving under its own weight in the developer storage chamber 253a is guided by the developer guide portion 253g, the amount of toner guided by the developer guide portion 253g closer to the developer center portion 253c is less than the amount of toner guided by the developer guide portion 253g closer to the receiving port 253b.

[0284] As described above, according to the third embodiment, the toner supplied from the toner cartridge 70 is guided by the developer guide portion 253g and moves away from the receiving port 253b in the longitudinal direction. This prevents toner from accumulating near the receiving port 253b in the developing unit 250. Furthermore, the developer guide portion 253g closer to the developing center portion 253c guides less toner, which prevents toner from concentrating at the developing center portion 253c and causing uneven toner distribution in the developing container 253a. This makes it possible to make the toner distribution in the developing container 253a uniform, thereby preventing image defects such as uneven density.

[0285] In the third embodiment, the shape of the receiving opening 253b is the same as that of the receiving opening 53b in the first embodiment. The first receiving opening 253bL and at least one of the left developing device guide portions 253gL are disposed on the inner surface 253d of the developing device frame so as to overlap at least partially in the longitudinal direction. The second receiving opening 253bR and at least one of the right developing device guide portions 253gR are disposed on the inner surface 253d of the developing device frame so as to overlap at least partially in the longitudinal direction.

[0286] (Variation) In the above embodiment, a configuration in which the first and second receiving ports are located closer to both ends of the developing roller in the axial direction than the central portion of the developing roller is illustrated, but the number and arrangement of the receiving ports are not limited to this example. For example, a configuration in which one or more receiving ports are located near one end of the axial direction, or a configuration in which one or more receiving ports are located near the central portion of the developing roller may be used.

[0287] In addition, the left and right developing guide sections each contain six developing guide sections. Although the above description is of an example in which the developer guide angles are different for all of the developer guide sections, the number of developer guide sections is not limited to this, as long as there are multiple developer guide sections. Also, while the above description is of an example in which the developer guide angles are all different for all of the developer guide sections, some of the developer guide sections may have the same developer guide angle. In this case, it is sufficient that there is a pair of developer guide sections among the multiple developer guide sections that satisfies the condition that the developer guide angle of one developer guide section located farther from the receiving inlet is larger than the developer guide angle of the other developer guide section. It is also preferable that there is no pair of developer guide sections among the multiple developer guide sections that satisfies the condition that the developer guide angle of one developer guide section located farther from the receiving inlet is smaller than the developer guide angle of the other developer guide section. The same applies to the developer guide length and the developer guide height.

[0288] In addition, in the above embodiment, an example was described in which the amount of toner guided in the longitudinal direction was varied by varying the development guide angle, development guide length, and development guide height of the development guide portion, but these may also be combined to vary the amount of toner guided.

[0289] In the above embodiment, the developer guide portion closer to the center of the development area (farther from the receiving port) has a configuration in which the amount of toner guided is smaller, but this configuration is not limiting as long as the distribution of toner in the developer storage chamber can be made uniform. For example, in an image forming apparatus in which the amount of toner used is large and the amount of toner in the center of the development area tends to be small, the developer guide portion closer to the center of the development area may have a configuration in which the amount of toner guided is larger.

[0290] In the above embodiment, the developer guide portion is provided on the inner surface of the developing frame, but the location where the developer guide portion is provided is not limited to this. The developer guide portion may be provided on any inner wall surface of the developer accommodating chamber as long as it is possible to guide the toner in the developer accommodating chamber in the axial direction as the rotary body rotates.

[0291] For example, at rotation phase GP2 in FIG. 17, the radially inner end (inner development surface 53i) of the inner development frame surface 53d is vertically higher than the radially outer end (outer development surface 53o), and the normal to the inner development frame surface 53d includes a vertically upward component. Therefore, at rotation phase GP2, toner moves from the radially inner side to the radially outer side along the inner development frame surface 53d, and the developer guide portion 53g guides the moving toner at rotation phase GP2. The present invention is not limited to this configuration. For example, the guide portion may be configured to guide toner flowing from the radially outer side to the radially inner side at rotation phase GP4 in FIG. 17.

[0292] The disclosure of this embodiment includes the following configuration. (Configuration 1) a rotary that is rotatable around a rotation axis that extends in an axial direction; a toner cartridge supported by the rotary and having an outlet for discharging toner; a developing unit supported by the rotary, the developing unit having a receiving port for receiving the toner discharged from the discharge port, a storage chamber for storing the toner received from the receiving port, and a developing roller for carrying the toner stored in the storage chamber; In an image forming apparatus comprising: a plurality of guide portions are provided in the accommodating chamber, the plurality of guide portions including a first guide portion and a second guide portion, the first guide portion being located between the second guide portion and the receiving port in the axial direction, and the second guide portion being farther from the receiving port than the first guide portion; the first guide portion and the second guide portion are configured to guide the toner accommodated in the accommodation chamber in a direction away from the receiving opening in the axial direction as the rotary rotates, A toner that can be moved in the axial direction by the first guide portion as the rotary rotates. an image forming apparatus, characterized in that the maximum amount of toner that can be moved in the axial direction by the second guide portion is smaller than the maximum amount of toner that can be moved in the axial direction by the second guide portion. (Configuration 2) Among the rotational phases of the rotary, a rotational phase in which the guide portion guides the toner in the axial direction away from the receiving port is defined as a first rotational phase, a rotational phase in which the positional relationship between the toner cartridge and the developing unit is such that the toner can move from the discharge port to the receiving port is defined as a second rotational phase, and a rotational phase in which the toner cartridge is attached to or detached from the rotary is defined as an attachment / detachment phase. 2. The image forming apparatus according to configuration 1, wherein the second rotation phase is located after the first rotation phase in one rotation of the rotary from the attachment / detachment phase. (Configuration 3) Further comprising a photosensitive drum, When the developing roller develops the electrostatic latent image formed on the photosensitive drum, the rotation phase of the rotary is defined as a development phase. 3. The image forming apparatus according to configuration 2, wherein the development phase is located after the first rotation phase in one rotation of the rotary from the attachment / detachment phase. (Configuration 4) 4. The image forming apparatus according to configuration 3, wherein the development phase is located after the second rotation phase in one rotation of the rotary from the attachment / detachment phase. (Configuration 5) 5. The image forming apparatus according to any one of configurations 1 to 4, wherein the guide portion is provided so as to extend in a direction inclined with respect to the axial direction. (Configuration 6) The image forming apparatus according to configuration 5, wherein a second end, which is one end of the guide portion, is farther from the receiving opening than a first end, which is the other end of the guide portion, in the direction in which the guide portion extends. (Configuration 7) If the distance between the first end and the second end in the axial direction is a guide distance, 7. The image forming apparatus according to configuration 6, wherein the guide distance of the second guide portion is shorter than the guide distance of the first guide portion. (Configuration 8) When the angle between the extending direction of the guide portion and the axial direction is defined as a guide angle, and the length of the guide portion along the extending direction of the guide portion is defined as a guide length, the guide length of the first guide portion and the guide length of the second guide portion are equal, 8. The image forming apparatus according to any one of configurations 5 to 7, wherein the guide angle of the second guide portion is larger than the guide angle of the first guide portion. (Configuration 9) When the angle between the extending direction of the guide portion and the axial direction is defined as a guide angle, and the length of the guide portion along the extending direction of the guide portion is defined as a guide length, the guide angle of the first guide portion and the guide angle of the second guide portion are equal, 8. The image forming apparatus according to any one of configurations 5 to 7, wherein the guide length of the second guide portion is shorter than the guide length of the first guide portion. (Configuration 10) the guide portion is a rib provided so as to protrude from an inner wall surface of the accommodation chamber, 5. The image forming apparatus according to any one of configurations 2 to 4, wherein the normal to the inner wall surface has a vertically upward component in the first rotation phase. (Configuration 11) The angle between the extending direction of the guide portion and the axial direction is defined as a guide angle, the length of the guide portion along the extending direction of the guide portion is defined as a guide length, and the height of the guide portion protruding from the inner wall surface is defined as a guide height. the guide length of the first guide portion and the guide length of the second guide portion are equal, the guide angle of the first guide portion and the guide angle of the second guide portion are equal, 11. The image forming apparatus according to configuration 10, wherein the guide height of the second guide portion is lower than the guide height of the first guide portion. (Configuration 12) 12. The image forming apparatus according to claim 10, wherein the receiving port is provided on the inner wall surface on which the guide portion is provided. (Configuration 13) 13. The image forming apparatus according to any one of configurations 1 to 12, wherein the position of at least one of the plurality of guide portions and the position of the receiving port at least partially overlap in the axial direction. (Configuration 14) The receiving port is provided at a position closer to an end portion than to a center portion in the axial direction, 14. The image forming apparatus according to any one of configurations 1 to 13, wherein the second guide portion is disposed at a position closer to the central portion in the axial direction than the first guide portion. (Configuration 15) The receiving port is a first receiving port provided at a position closer to one end than to a center portion in the axial direction; a second receiving port provided at a position closer to the other end than the central portion in the axial direction; Including, the plurality of guide portions provided between the central portion and the one end portion are configured to guide the toner in a direction away from the first receiving opening, The image forming apparatus according to any one of configurations 1 to 14, wherein the plurality of guide portions provided between the central portion and the other end portion of the plurality of guide portions are configured to guide toner in a direction away from the second receiving port. (Configuration 16) 13. The image forming apparatus according to any one of configurations 10 to 12, wherein the inner wall surface on which the guide portion is provided is a surface that intersects with the rotation direction of the rotary. [Explanation of symbols]

[0293] 1: image forming apparatus, 50: developing unit, 51: developing roller, 53a: developing chamber, 53b: receiving port, 53g: developing guide portion, 70: toner cartridge, 71b: discharge port, 90A: rotary assembly

Claims

1. a rotary that is rotatable around a rotation axis that extends in an axial direction; a toner cartridge supported by the rotary and having an outlet for discharging toner; a developing unit supported by the rotary, the developing unit having a receiving port for receiving the toner discharged from the discharge port, a storage chamber for storing the toner received from the receiving port, and a developing roller for carrying the toner stored in the storage chamber; In an image forming apparatus comprising: a plurality of guide portions are provided in the accommodation chamber, the plurality of guide portions including a first guide portion and a second guide portion, the first guide portion being located between the second guide portion and the receiving port in the axial direction, and the second guide portion being farther from the receiving port than the first guide portion; the first guide portion and the second guide portion are configured to guide the toner accommodated in the accommodation chamber in a direction away from the receiving opening in the axial direction as the rotary rotates, An image forming apparatus characterized in that the maximum amount of toner that can be moved in the axial direction by the second guide portion is less than the maximum amount of toner that can be moved in the axial direction by the first guide portion as the rotary rotates.

2. Among the rotational phases of the rotary, a rotational phase in which the guide portion guides the toner in the axial direction away from the receiving port is defined as a first rotational phase, a rotational phase in which the positional relationship between the toner cartridge and the developing unit is such that the toner can move from the discharge port to the receiving port is defined as a second rotational phase, and a rotational phase in which the toner cartridge is attached to or detached from the rotary is defined as an attachment / detachment phase.

2. The image forming apparatus according to claim 1, wherein the second rotation phase is located after the first rotation phase in one rotation of the rotary from the attachment / detachment phase.

3. Further comprising a photosensitive drum, When the developing roller develops the electrostatic latent image formed on the photosensitive drum, the rotation phase of the rotary is defined as a development phase.

3. The image forming apparatus according to claim 2, wherein the development phase is located after the first rotation phase in one rotation of the rotary from the attachment / detachment phase.

4. 4. The image forming apparatus according to claim 3, wherein the development phase is located after the second rotation phase in one rotation of the rotary from the attachment / detachment phase.

5. 5. The image forming apparatus according to claim 1, wherein the guide portion is provided so as to extend in a direction inclined with respect to the axial direction.

6. 6. The image forming apparatus according to claim 5, wherein a second end portion of the guide portion is farther from the receiving opening than a first end portion of the guide portion in the extending direction of the guide portion.

7. When the distance between the first end and the second end in the axial direction is defined as a guide distance, The image forming apparatus according to claim 6 , wherein the guide distance of the second guide portion is shorter than the guide distance of the first guide portion.

8. When the angle between the extending direction of the guide portion and the axial direction is defined as a guide angle, and the length of the guide portion along the extending direction of the guide portion is defined as a guide length, the guide length of the first guide portion and the guide length of the second guide portion are equal, The image forming apparatus according to claim 5 , wherein the guide angle of the second guide portion is larger than the guide angle of the first guide portion.

9. When the angle between the extending direction of the guide portion and the axial direction is defined as a guide angle, and the length of the guide portion along the extending direction of the guide portion is defined as a guide length, the guide angle of the first guide portion and the guide angle of the second guide portion are equal, The image forming apparatus according to claim 5 , wherein the guide length of the second guide portion is shorter than the guide length of the first guide portion.

10. the guide portion is a rib provided so as to protrude from an inner wall surface of the accommodation chamber, 5. The image forming apparatus according to claim 2, wherein a normal to the inner wall surface has a vertically upward component in the first rotation phase.

11. The angle between the extending direction of the guide portion and the axial direction is defined as a guide angle, the length of the guide portion along the extending direction of the guide portion is defined as a guide length, and the height of the guide portion protruding from the inner wall surface is defined as a guide height. the guide length of the first guide portion and the guide length of the second guide portion are equal, the guide angle of the first guide portion and the guide angle of the second guide portion are equal, The image forming apparatus according to claim 10 , wherein the guide height of the second guide portion is lower than the guide height of the first guide portion.

12. The image forming apparatus according to claim 10 , wherein the receiving port is provided on the inner wall surface on which the guide portion is provided.

13. 5. The image forming apparatus according to claim 1, wherein the position of at least one of the plurality of guide portions and the position of the receiving opening at least partially overlap in the axial direction.

14. The receiving port is provided at a position closer to an end portion than to a center portion in the axial direction, 5. The image forming apparatus according to claim 1, wherein the second guide portion is disposed at a position closer to the central portion in the axial direction than the first guide portion.

15. The receiving port is a first receiving port provided at a position closer to one end than to a center portion in the axial direction; a second receiving port provided at a position closer to the other end than the center in the axial direction; Including, the plurality of guide portions provided between the central portion and the one end portion are configured to guide the toner in a direction away from the first receiving opening, An image forming apparatus according to any one of claims 1 to 4, wherein the plurality of guide portions provided between the central portion and the other end portion of the plurality of guide portions are configured to guide toner in a direction away from the second receiving port.

16. 11. The image forming apparatus according to claim 10, wherein the inner wall surface on which the guide portion is provided is a surface that intersects with the rotation direction of the rotary.

Images