Image forming apparatus

Abstract

An image forming apparatus is disclosed. The present invention aims to reduce a moving member for moving a magnet relative to a developer. An image forming apparatus includes: a developing unit including an accommodating portion, a developing member, and a magnet unit located inside the accommodating portion and supported to be movable relative to the accommodating portion in a moving direction; a rotary device; and a magnetic sensor. The rotation period of the rotation device includes a first period of time. In the first period, the movement direction includes a vertically downward direction. The first period includes a contact period during which the magnet unit is received by the developer. The contact period includes a timing at which the center of rotation of the rotary device, the magnet unit, and the magnetic sensor are aligned on a straight line in a radial direction of rotation of the rotary device.

Description

TECHNICAL FIELD

[0001] The present application relates to an image forming apparatus that forms an image on a recording material. BACKGROUND

[0002] The image forming apparatus discussed in Japanese Patent Application Publication No. 2011-175056 includes a movable magnet inside a housing portion that houses a developer, and detects the amount of the developer in the housing portion by detecting a magnetic field generated by the magnet.

[0003] In order to accurately detect the remaining level of the developer, the image forming apparatus discussed in Japanese Patent Application Publication No. 2011-175056 further includes a moving member that moves the magnet relative to the developer.

[0004] Since the image forming apparatus discussed in Japanese Patent Application Publication No. 2011-175056 includes the moving member inside the housing portion, the amount of the developer that can be housed in the housing portion is reduced due to the presence of the moving member. SUMMARY

[0005] The present application aims to reduce the moving member for moving the magnet relative to the developer.

[0006] An aspect of the present application is as follows.

[0007] An image forming apparatus includes: a developing unit including a housing portion configured to house a developer, a developing member configured to develop an electrostatic latent image formed on a photosensitive drum with the developer housed in the housing portion, and a magnet unit including a magnet, the magnet unit being located inside the housing portion and supported to be movable relative to the housing portion in a moving direction; a rotary device configured to rotate, the rotary device including the developing unit; and a magnetic sensor, wherein a rotation period in which the rotary device performs one rotation includes a first period, wherein in the first period, the moving direction includes a vertically downward component, wherein the first period includes a contact period during which the magnet unit contacts the developer and is received by the developer, wherein the contact period includes a collocation timing at which, when viewed in a rotation axis direction of the rotary device, a rotation center of the rotary device, the magnet unit, and the magnetic sensor are aligned on a straight line in a radial direction of the rotation of the rotary device, and wherein the magnetic sensor is configured to output a signal based on a magnetic field generated by the magnet in at least a portion of the first period.

[0008] Further features of the present application will become clear on the basis of the following description of exemplary embodiments, given by way of example, with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0009] FIG. 1 is a schematic view illustrating an image forming apparatus according to a first embodiment.

[0010] FIG. 2 is a configuration view illustrating an image forming apparatus according to the first embodiment.

[0011] FIG. 3 is a schematic view illustrating a developing unit, a toner cartridge, and a tray according to the first embodiment.

[0012] FIG. 4A and FIG. 4B is a cross-sectional view of an image forming apparatus according to the first embodiment.

[0013] FIG. 5 is a perspective view of a rotary body according to the first embodiment.

[0014] FIGS. 6A-6C is a perspective view of an image forming apparatus according to the first embodiment.

[0015] FIG. 7A and FIG. 7B is a cross-sectional view of an image forming apparatus according to the first embodiment.

[0016] FIG. 8 is an explanatory view illustrating a rotary body according to the first embodiment.

[0017] FIG. 9 is an explanatory view illustrating a rotary body according to the first embodiment.

[0018] FIG. 10 is an explanatory view illustrating a rotary body according to the first embodiment.

[0019] FIG. 11A and FIG. 11B is an explanatory view illustrating a configuration related to movement of a tray according to the first embodiment.

[0020] FIG. 12A and FIG. 12B is an explanatory view illustrating a configuration related to movement of a tray according to the first embodiment.

[0021] FIG. 13 is a plan view of a rotary body according to the first embodiment.

[0022] FIG. 14A and FIG. 14B is an explanatory view illustrating a magnet unit according to the first embodiment.

[0023] FIG. 15is a block diagram for describing a control unit according to the first embodiment.

[0024] FIG. 16 is a cross-sectional view of a rotary device main body according to the first embodiment.

[0025] FIG. 17 is a cross-sectional view of a rotary device main body according to the first embodiment.

[0026] FIG. 18 is a cross-sectional view of a rotary device main body according to the first embodiment.

[0027] FIGS. 19A-19C is an explanatory diagram illustrating an output waveform of a magnetic sensor according to the first embodiment.

[0028] FIGS. 20A-20D is a plan view of a rotary device main body according to the first embodiment. DETAILED DESCRIPTION

[0029] Embodiments of the present application will be described below with reference to the accompanying drawings.

[0030] Reference will be made to FIGS. 1-12B An image forming apparatus 1 according to the first embodiment will be described.

[0031] In the following description and drawings, a vertical direction when the image forming apparatus 1 is installed on a horizontal plane will be referred to as a Z direction. A direction intersecting the Z direction and along a rotation axis 90C of a rotary device main body 90 (a rotary device rotation axis direction) to be described below will be referred to as a Y direction. A direction intersecting both the Z direction and the Y direction will be referred to as an X direction. The X direction and the Y direction are desirably horizontal directions. The X direction, the Y direction, and the Z direction are desirably orthogonal to each other. In appropriate cases, the directions of arrows X, Y, and Z shown in the drawings will be referred to as +X side, +Y side, and +Z side, respectively, and the respective opposite sides will be referred to as -X side, -Y side, and -Z side.

[0032] (Overall configuration of image forming apparatus)

[0033] The overall configuration of the image forming apparatus 1 will be described first. The image forming apparatus 1 is a laser beam printer that forms an image on a sheet S in an electrophotographic manner. More specifically, the image forming apparatus 1 is a color laser beam printer that includes four developing units 50y, 50m, 50c, and 50k. Various sheet materials of different sizes and materials can be used as the sheet S as a recording material (recording medium). Examples include sheets of paper such as regular paper and thick paper, plastic films, cloth, surface-treated sheet materials such as coated paper, and sheet materials of special shapes such as envelopes and index paper.

[0034] Reference will be made to FIG. 1 ,FIG. 2 and FIG. 3 A schematic configuration and an image forming operation of the image forming apparatus 1 are described. FIG. 1 is a schematic view illustrating a cross-sectional configuration of the image forming apparatus 1. FIG. 2 is a view for describing a drive source of the image forming apparatus 1. FIG. 3 is a conceptual view illustrating a configuration for supplying toner from the toner cartridge 70 to the developing unit 50.

[0035] As shown in FIG. 1 , the image forming apparatus 1 includes an image forming apparatus main body (hereinafter referred to as an apparatus main body) 1A and toner cartridges 70y, 70m, 70c, and 70k detachably attached to the apparatus main body 1A. The apparatus main body 1A according to the present embodiment refers to the image forming apparatus 1 excluding the toner cartridges 70y, 70m, 70c, and 70k.

[0036] The apparatus main body 1A of the image forming apparatus 1 includes a drum-shaped (cylindrical) electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum) 2 as an image bearing member that bears an electrostatic latent image. A charging roller 3, a scanner 4 serving as an exposure device, and a cleaning unit 6 are arranged in the vicinity of the photosensitive drum 2.

[0037] The charging roller 3 is an example of a charging unit for uniformly charging the photosensitive drum 2. The scanner 4 is an example of an exposure unit that exposes the photosensitive drum 2 with laser irradiation based on image information. The photosensitive drum 2 charged with the laser irradiation forms an electrostatic latent image on the surface of the photosensitive drum 2. The cleaning unit 6 is an example of a cleaning member that removes toner remaining on the surface of the photosensitive drum 2.

[0038] The apparatus main body 1A further includes a sheet storage unit 300, a pickup roller 310, a feed roller 311, a separation roller 312, a conveyance roller pair 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 unit that feeds a sheet S. The feed roller 311 and the separation roller 312 are examples of a separation conveyance unit that separates the sheets S one by one using a frictional force and conveys the separated sheets S. The secondary transfer roller 12 is an example of a transfer unit that transfers an image from the intermediate transfer belt 10a to the sheet S.

[0039] The intermediate transfer unit 10 includes 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 member that bears an image transferred (primary transfer) from the photosensitive drum 2 and conveys the image so as to be transferred (secondary transfer) to the sheet S. The intermediate transfer belt 10a is stretched across the belt drive roller 10b and the tension roller 10c. The belt drive roller 10b is a drive member that is driven to rotate by a drive source and thereby conveys the intermediate transfer belt 10a.

[0040] The device main body 1A further includes a rotary device main body (rotary device, rotary body, or developing apparatus) 90 including developing units 50y, 50m, 50c, and 50k. As will be described below, in the present embodiment, trays (support members) 80y, 80m, 80c, and 80k are attached to the rotary device main body 90. The toner cartridges 70y, 70m, 70c, and 70k are detachably attached to the trays 80y, 80m, 80c, and 80k.

[0041] In the following description, a plurality of members having similar functions can be referred to by additional numerals. For example, one of the toner cartridges 70y, 70m, 70c, and 70k can be referred to as a first toner cartridge, one of the remaining three can be referred to as a second toner cartridge, one of the remaining two can be referred to as a third toner cartridge, and the last one can be referred to as a fourth toner cartridge. Similarly, one of the trays 80y, 80m, 80c, and 80k can be referred to as a first tray, one of the remaining three can be referred to as a second tray, one of the remaining two can be referred to as a third tray, and the last one can be referred to as a 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, 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. Such numbering is used merely for the convenience of description, and can be appropriately interchanged in principle.

[0042] The developing units (first to fourth developing units) 50y, 50m, 50c, and 50k are examples of developing members that develop (visualize) an electrostatic latent image formed on the photosensitive drum 2 into a toner image using toner of each corresponding color. The developing units 50y, 50m, 50c, and 50k are developing members that develop a latent electrostatic image formed on the photosensitive drum 2 using yellow toner, magenta toner, cyan toner, and black toner, respectively. More specifically, the developing members develop an electrostatic latent image formed on the photosensitive drum 2 with a developer housed in a developing frame 53. The developing units 50y, 50m, 50c, and 50k can be arranged in an order different from that shown in FIG. 1. FIG. 1 The developing units 50y, 50m, 50c, and 50k are arranged in the order shown in FIG. 1.

[0043] The developing unit 50y includes a developing roller 51y, a supply roller 52y, and a developing blade. The developing roller 51y is a developer carrying member that carries toner as a developer and rotates to supply the toner to the photosensitive drum 2. The supply roller 52y is a supply member positioned in contact with the developing roller 51y and supplies the toner to the developing roller 51y. The developing blade is a regulating member that regulates the thickness of a toner layer carried on the developing roller 51y. The other developing units 50m, 50c, and 50k include similar developing rollers 51m, 51c, and 51k, supply rollers 52m, 52c, and 52k, and developing blades.

[0044] The toner cartridges 70y, 70m, 70c, and 70k corresponding to the developing units 50y, 50m, 50c, and 50k are attached to the rotary device body 90. The toner cartridges 70y, 70m, 70c, and 70k each contain yellow toner, magenta toner, cyan toner, and black toner as toner to be supplied to the developing units 50y, 50m, 50c, and 50k, respectively. One of the four colors of toner can be referred to as a first toner, one of the remaining three colors of toner can be referred to as a second toner, one of the remaining two colors of toner can be referred to as a third toner, and the last one can be referred to as a fourth toner. For example, the black toner can be taken as an example of the first toner, and the magenta toner can be taken as an example of the second toner. Such numbering is used only for the convenience of description, and can be appropriately interchanged in principle.

[0045] The rotary device body 90 includes a rotary device 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 device frame 90f as a rotatable support member.

[0046] The trays 80y, 80m, 80c, and 80k are attached to the rotary device body 90. The combination of the rotary device body 90 and the trays 80y, 80m, 80c, and 80k can be referred to as a rotary device unit 90U. In other words, the rotary device unit 90U includes the rotary device body 90 and the trays 80y, 80m, 80c, and 80k.

[0047] The toner cartridges 70y to 70k are held by the trays 80y to 80k in a detachably attached manner. As will be described below, the trays 80y to 80k are supported to be slidable to the outside of the rotary device body 90. The combination of the rotary device unit 90U and the toner cartridges 70y, 70m, 70c, and 70k can be referred to as a rotary device assembly 90A. In other words, the rotary device assembly 90A includes the rotary device unit 90U and the toner cartridges 70y, 70m, 70c, and 70k.

[0048] As will be described below, the rotary device body 90 can be rotated around a rotation axis (a center of rotation) 90C. The rotation axis 90C matches the rotation axis of the rotary device frame 90f and the rotary device assembly 90A. The rotation axis 90C is substantially parallel to the rotation axis (the center of rotation) of the photosensitive drum 2.

[0049] By rotating around the rotation axis 90C, the rotary device body 90 can assume a developing orientation in which one of the developing rollers 51y, 51m, 51c, and 51k is opposite the photosensitive drum 2. The orientation in which the developing roller 51y is opposite the photosensitive drum 2 will be referred to as a yellow developing orientation. The orientation in which the developing roller 51m is opposite the photosensitive drum 2 will be referred to as a magenta developing orientation. The orientation in which the developing roller 51c is opposite the photosensitive drum 2 will be referred to as a cyan developing orientation. The orientation in which the developing roller 51k is opposite the photosensitive drum 2 will be referred to as a black developing orientation. In other words, the rotary device body 90 can be rotated 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 orientation is an example of a first developing orientation in which a first developing roller (the developing roller 51k) is opposite the photosensitive drum 2. The other developing orientations are examples of second developing orientations in which second developing rollers (the developing rollers 51y to 51c) are opposite the photosensitive drum 2. The yellow developing orientation, the magenta developing orientation, the cyan developing orientation, and the black developing orientation can be referred to as a first developing orientation, a second developing orientation, a third developing orientation, and a fourth developing orientation. Such numbering is used merely for the convenience of description, and can be appropriately interchanged in principle.

[0050] As shown in FIG. 1A, the device body 1A includes a motor M1, M2, and M3 serving as a driving source. As will be described below, the motor M1 supplies a driving force for rotating the rotary device body 90 around the rotation axis 90C. In other words, the motor M1 rotates the rotary device assembly 90A and the rotary device unit 90U around the rotation axis 90C. FIG. 2 The device body 1A also includes a driving apparatus, not shown, which includes the motor M2 and a transmission apparatus. The transmission apparatus includes drive racks 15L and 15R serving as driving gears to be described below and a transmission unit 15t. The driving force of the motor M2 is transmitted to the drive racks 15L and 15R through the transmission unit 15t. In other words, the motor M2 is configured to drive the drive racks 15L and 15R and move the trays 80y, 80m, 80c, and 80k relative to the rotary device body 90 via the drive racks 15L and 15R.

[0051]

[0052] ​The motor M3 drives members other than the members driven by the motors Ml and M2. For example, the motor M3 drives the photosensitive drum 2, the developing units 50y, 50m, 50c, and 50k, the pickup roller 310, the feed roller 311, the transfer roller pair 320, the secondary transfer roller 12, the belt driving roller 10b, and the fixing device 40.

[0053] The members to be driven by the motors Ml, M2, and M3 can be appropriately changed. The functions of any two or all of the motors Ml, M2, and M3 can be integrated into one motor. A driving source other than the motors Ml, M2, and M3 can be added.

[0054] 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 toner colors. The developing units 50y, 50m, 50c, and 50k have a common basic configuration and function. The toner cartridges 70y, 70m, 70c, and 70k have a common basic configuration and function. The trays 80y, 80m, 80c, and 80k have a common basic configuration and function. Therefore, when it is not necessary to distinguish, the suffixes y, m, c, and k will be omitted to describe one of the four units, cartridges, or trays.

[0055] As shown in FIG. 3 The toner cartridge 70 includes a toner frame 71. The toner frame 71 includes a toner containing portion 71a that contains toner and a discharge opening 71b that communicates with the toner containing portion 71a.

[0056] The developing unit 50 includes a developing frame (containing frame) 53. The developing units 50y, 50m, 50c, and 50k include developing frames 53y, 53m, 53c, and 53k, respectively. The developing frames 53y, 53m, 53c, and 53k have a common configuration and function. Therefore, when it is not necessary to distinguish, the suffixes y, m, c, and k will be omitted to describe one of the four developing frames 53.

[0057] The developing frame 53 includes a developing containing portion 53a and a receiving opening 53b that communicates with the developing containing portion (toner supply chamber) 53a. As will be described later FIG. 13 As shown in FIG. 3 The developing roller 51 and the supply roller 52, which are omitted in

[0058] 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. 4A ) of the developing unit 50k including the first housing portion is an example of a first housing frame including a first housing portion. The developing frame 53m ( FIG. 4A ) of the developing unit 50m including the developing housing portion 53a is an example of a second developing frame including a second housing portion. The rotary device body 90 is an example of a rotatable rotary device including a first developing roller, a second developing roller, a first housing frame including a first housing portion, and a second housing frame including a second housing portion. In the present embodiment, the rotary device body 90 includes first to fourth developing rollers and first to fourth housing frames.

[0059] As will be described below, the toner cartridge 70 is movable relative to the developing frame 53 to an attached position and a retracted position retracted from the attached position. When the toner cartridge 70 is in the attached position relative to the developing frame 53, the discharge opening 71b opposes the receiving opening 53b. In other words, the toner housing portion 71a of the toner cartridge 70 and the developing housing portion 53a of the developing unit 50 communicate via the discharge opening 71b and the receiving opening 53b. At least a portion of the receiving opening 53b is positioned below at least a portion of the discharge opening 71b in supplying toner from the toner cartridge 70 to the developing unit 50.

[0060] The toner housed in the toner housing portion 71a is then discharged from the discharge opening 71b. The toner discharged from the discharge opening 71b is housed into the developing housing portion 53a via the receiving opening 53b. The toner housed in the developing housing portion 53a is supplied to the developing roller 51 by the supply roller 52. By this route, the toner housed in the toner housing portion 71a is supplied to the developing roller 51.

[0061] The toner cartridge 70 desirably includes a sealing member (first sealing member) not shown that covers the discharge opening 71b. The developing unit 50 desirably includes a sealing member (second sealing member) not shown that covers the receiving opening 53b.

[0062] In a state where the toner cartridge 70 is not attached to the developing unit 50, the discharge opening 71b and the receiving opening 53b are desirably covered by the respective sealing members so that leakage of toner from the discharge opening 71b and the receiving opening 53b is prevented.

[0063] (Image forming operation)

[0064] An image forming operation according to the present embodiment will be described. The photosensitive drum 2 is first rotated in synchronization with the rotation of the intermediate transfer belt 10a in the direction of arrow A1 in FIG. 1The direction of the arrow in the middle (counterclockwise) is rotated. The surface of the photosensitive drum 2 is uniformly charged by the charging roller 3.

[0065] In the case of forming color images on the sheet S, as will be described below, the rotary device main body 90 supporting the developing units 50y, 50m, 50c, and 50k is rotated in the direction of the arrow in the middle (clockwise). The developing rollers 51y, 51m, 51c, and 51k are moved to the developing positions one by one, and the electrophotographic process is repeated. FIG. 1 The direction of the arrow in the middle (counterclockwise) is rotated. The surface of the photosensitive drum 2 is uniformly charged by the charging roller 3.

[0066] First, the scanner 4 emits laser light based on image data corresponding to a yellow image, thereby forming an electrostatic latent image corresponding to the yellow image on the surface of the photosensitive drum 2. In parallel with the formation of the electrostatic latent image, the motor M1 rotates the rotary device main body 90 to bring the rotary device main body 90 into a yellow developing orientation. When the rotary device main body 90 is in the yellow developing orientation, the developing roller 51y is in the developing position and develops the electrostatic latent image formed on the photosensitive drum 2 with yellow toner.

[0067] In the present embodiment, each of the developing rollers 51y, 51m, 51c, and 51k is an elastic roller that is a metal shaft coated with rubber. At the developing positions, each of the developing rollers 51y, 51m, 51c, and 51k develops the electrostatic latent image in contact with the photosensitive drum 2. In other words, the image forming apparatus 1 according to the present embodiment uses a contact developing method. However, each of the developing rollers 51y, 51m, 51c, and 51k can develop the electrostatic latent image across a gap from the photosensitive drum 2 at the developing positions. In other words, the image forming apparatus 1 can employ a non-contact developing method.

[0068] As the yellow toner image is developed, the yellow toner image on the photosensitive drum 2 is primary-transferred to the intermediate transfer belt 10a by the primary transfer roller 11 located inside the intermediate transfer belt 10a.

[0069] The rotary device main body 90 is then rotated to move the developing rollers 51m, 51c, and 51k to the developing positions in turn, thereby forming toner images of respective colors. More specifically, after the yellow toner image is formed on the intermediate transfer belt 10a, the rotary device main body 90 assumes a magenta developing orientation, and a magenta toner image is formed on the intermediate transfer belt 10a. After the magenta toner image is formed on the intermediate transfer belt 10a, the rotary device main body 90 assumes a cyan developing orientation, and a cyan toner image is formed on the intermediate transfer belt 10a. After the cyan toner image is formed on the intermediate transfer belt 10a, the rotary device main body 90 assumes a black developing orientation, and a black toner image is formed on the intermediate transfer belt 10a. After the black toner image is formed on the intermediate transfer belt 10a, the rotary device main body 90 assumes the yellow developing orientation again, and a yellow toner image is formed on the intermediate transfer belt 10a. FIG. 1The intermediate transfer belt 10a is rotated in the direction of the arrow (clockwise) around the rotation axis 90C and returns to the yellow developing orientation. Note that the first image to be formed on the intermediate transfer belt 10a can be any color. For example, a black toner image can be formed first.

[0070] The primary transfer is repeated so that the toner images of the four colors are superimposed on the intermediate transfer belt 10a, thereby forming a color image on the intermediate transfer belt 10a. The secondary transfer roller 12 and the cleaning device 13 remain out of contact with the intermediate transfer belt 10a until the color image is formed on the intermediate transfer belt 10a.

[0071] Meanwhile, the sheet S is fed by the pickup roller 310 from the sheet storage unit 300 located in the lower portion of the device main body 1A. The sheet S is separated one by one by the feed roller 311 and the separation roller 312, and is fed to the convey roller pair 320. The convey roller pair 320 delivers the fed sheet S to the transfer portion (secondary transfer portion), which is the nip portion 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) to the surface of the conveyed sheet S.

[0072] The sheet S on which the color image is transferred is conveyed to the fixing device 40. In the fixing device 40, the sheet S is heated and pressed, whereby the image is fixed to the sheet S. The sheet S that has passed through the fixing device 40 is discharged from the image forming apparatus 1 as a product.

[0073] Now, in the case of forming a monochrome image, the rotary device main body 90 assumes the black developing orientation. In this state, the photosensitive drum 2 is charged and exposed to form an electrostatic latent image on the surface of the photosensitive drum 2. Then, the electrostatic image is developed with black toner by the developing roller 51k located at the developing position. The black toner image is primary transferred to the intermediate transfer belt 10a, and then secondary transferred to the sheet S. The subsequent steps are similar to the case of the color image.

[0074] (Rotary device configuration)

[0075] The configuration of the rotary device main body 90 will be described with reference to FIG. 1 , FIG. 4A , FIG. 4B and FIG. 5 .

[0076] FIG. 4A and FIG. 4B are cross-sectional views of the image forming apparatus 1 that illustrate the rotary device main body 90 and its vicinity. FIG. 4A and FIG. 4B are cross-sectional views of the image forming apparatus 1 taken along an imaginary plane perpendicular to the rotation axis 90C of the rotary device main body 90. FIG. 5 is a perspective view of the rotary device main body 90.

[0077] As described above, the toner cartridges 70y to 70k are detachably attached to the rotary device main body 90. When the toner in the toner cartridges 70y to 70k is used up, the user can replenish the toner for the image forming apparatus 1 by replacing the toner cartridges 70y to 70k.

[0078] As FIG. 1 indicated in FIG. 1A, the apparatus main body 1A includes a frame 16 that houses the rotary device main body 90.

[0079] The frame 16 is a main body frame of the image forming apparatus 1 according to the present embodiment. The frame 16 is a housing (skeleton) of the apparatus main body 1A that is configured of a frame and an exterior member. In the present embodiment, the frame 16 has a substantially rectangular parallelepiped shape.

[0080] The frame 16 has an opening 16a. More specifically, the frame 16 includes a side surface that extends in a direction intersecting the horizontal direction. This side surface constitutes at least a part of the outer surface of the apparatus main body 1A on the +X side. The opening 16a is located in this side surface. In the discharge direction in which the sheet S on which an image is formed is discharged from the discharge port of the apparatus main body 1A, this side surface is a side surface located downstream of the discharge port. The user can access the sheet storage unit 300 from the side surface side of the image forming apparatus 1 to replenish the sheet S and take out the sheet S discharged from the discharge port. Therefore, this side surface can be referred to as the front surface (front surface) of the apparatus main body 1A.

[0081] The toner cartridges 70y, 70m, 70c, and 70k can be detached from and attached to the rotary device main body 90 through the opening 16a. In other words, the toner cartridge 70k can be regarded as an example of a first toner cartridge that houses toner to be supplied to a first developing roller (developing roller 51k) and that can be detachably attached to a rotary device (rotary device main body 90) through the opening 16a of the frame 16 of the apparatus main body 1A. The toner cartridge 70m can be regarded as an example of a second toner cartridge that houses toner to be supplied to a second developing roller (developing roller 51m) and that can be detachably attached to a rotary device (rotary device main body 90) through the opening 16a of the frame 16 of the apparatus main body 1A.

[0082] In the present embodiment, the toner cartridges 70y, 70m, 70c, and 70k are detached from or attached to the rotary device main body 90 through the opening 16a while being supported by the trays 80y, 80m, 80c, and 80k.

[0083] In other words, the user can detach or attach the toner cartridges 70y to 70k from or to the rotary device main body 90 via the trays 80y to 80k.

[0084] The opening 16a is located in a side surface of the frame 16. In the present embodiment, the side surface is a surface substantially parallel to the rotation axis 90C of the rotary device body 90. Thus, when the toner cartridge 70 is replaced, the toner cartridge 70 passes through the opening 16a in a direction intersecting the rotation axis 90C, desirably a direction orthogonal to the rotation axis 90C.

[0085] The image forming apparatus 1 includes a door 14 that covers the opening 16a of the frame 16. The door 14 is an openable and closable member that can be moved to a closed position (see FIG. 6A ) in which the door 14 covers the opening 16a and an open position (see FIG. 6B and FIG. 6C ) in which the opening 16a is exposed.

[0086] As described above, in the present embodiment, the toner cartridge 70 is configured to be detachably attached to the rotary device body 90 via the tray 80. This enables stable detachment and attachment of the toner cartridge 70 to the rotary device body 90.

[0087] More specifically, the user can replace the toner cartridge 70 by detaching and attaching the toner cartridge 70 from and to the tray 80, which is configured to be movable relative to the rotary device body 90, i.e., relative to the apparatus body 1A. In a configuration in which the user replaces the toner cartridge by directly inserting / removing the toner cartridge into / from the apparatus body, the user would need to insert the toner cartridge into a predetermined attachment position within the apparatus body. In the present embodiment, the tray 80 that supports the toner cartridge 70 can be moved so that the toner cartridge 70 is moved to the attachment position. Thus, the user can replace the toner cartridge 70 by a simple operation of placing the toner cartridge 70 on the tray 80, thereby having improved operability.

[0088] In a case where the Y direction parallel to the rotation axis 90C of the rotary device body 90 is taken as a longitudinal direction thereof, the toner cartridge 70 has an elongated shape. In other words, the longitudinal dimension of the toner cartridge 70 is greater than the height and width in a cross section orthogonal to the longitudinal direction. In handling such an elongated toner cartridge 70, if the opening 16a is located in a side surface of the frame 16 substantially 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 moving distance. This facilitates replacement of the toner cartridge 70 compared to, for example, insertion and removal of the toner cartridge 70 through an opening located in a side surface of the frame 16 on a side (+Y side or -Y side) of the longitudinal direction of the toner cartridge 70.

[0089] The rotary device main body 90 can be rotated about the rotation axis 90C to assume a replacement orientation in which one of the toner cartridges 70y to 70k can be detached from the rotary device main body 90. The replacement orientation in which the toner cartridge 70y can be detached will be referred to as a yellow replacement orientation. The replacement orientation in which the toner cartridge 70m can be detached will be referred to as a magenta replacement orientation. The replacement orientation in which the toner cartridge 70c can be detached will be referred to as a cyan replacement orientation.

[0090] The replacement orientation in which the toner cartridge 70k can be detached will be referred to as a black replacement orientation.

[0091] The black replacement orientation is an example of a first replacement orientation in which a first toner cartridge can be detached from the rotary device main body 90. The yellow replacement orientation, the magenta replacement orientation, and the cyan replacement orientation are examples of second replacement orientations in which second toner cartridges can be detached from the rotary device main body 90. The yellow replacement orientation, the magenta replacement orientation, the cyan replacement orientation, and the black replacement orientation can be referred to as a first replacement orientation to a fourth replacement orientation. Such numbering is used merely for the convenience of description, and can be interchanged as appropriate in principle.

[0092] The rotary device main body 90 can be rotated clockwise about the rotation axis 90C in FIG. 1 , and sequentially assume the yellow replacement orientation, the magenta replacement orientation, the cyan replacement orientation, and the black replacement orientation. In the present embodiment, the rotary device main body 90 alternates the development orientation and the replacement orientation by being rotated clockwise about the rotation axis 90C in FIG. 1 . For example, in FIG. 1 , the rotary device main body 90 is in the black development orientation. When the rotary device main body 90 is rotated clockwise from this state, the rotary device main body 90 switches the orientation in the order of the cyan replacement orientation, the yellow development orientation, the black replacement orientation, the magenta development orientation, the yellow replacement orientation, the cyan development orientation, and the magenta replacement orientation. When the rotary device main body 90 in the magenta replacement orientation is rotated clockwise, the rotary device main body 90 returns to the black development orientation. That is, the rotary device main body 90 can be rotated one turn (360°) or more clockwise.

[0093] FIG. 4A A cross section of the rotary device main body 90 in the development orientation, specifically the yellow development orientation, is illustrated. FIG. 4B A cross section of the rotary device main body 90 in the replacement orientation, specifically the black replacement orientation, is illustrated.

[0094] As shown in FIG. 4A and FIG. 4B , four trays 80y to 80k are attached to the rotary device main body 90. The trays 80y to 80k hold the respective toner cartridges 70y to 70k. In FIG. 4A andFIG. 4B In this state, the trays 80y to 80k are housed inside the rotary device main body 90. This state can be regarded as the toner cartridges 70y to 70k being attached to the developing units 50y to 50k.

[0095] As described above, the toner cartridge 70 can be moved to the attached position and retracted from the attached position to the retracted position with respect to the developing frame 53 of the developing unit 50. Specifically, the first toner cartridge (toner cartridge 70k) can be moved to the first attached position and the first retracted position with respect to the first housing frame (developing frame 53k). The second toner cartridge (toner cartridge 70m) can be moved to the second attached position and the second retracted position with respect to the second housing frame (developing frame 53m).

[0096] When the toner cartridge 70 is in the attached position with respect to the developing frame 53, as shown in FIG. 1, the discharge opening 71b and the receiving opening 53b face each other. In this state, the toner cartridge 70 is configured so that toner is supplied to the developing housing portion 53a through the receiving opening 53b (the opening in the housing frame). FIG. 3

[0097] The device main body 1A includes a moving device configured to move the toner cartridge 70 from the attached position to the retracted position with respect to the rotary device main body 90 (more specifically, with respect to the developing frame 53 of the developing unit 50). The moving device will be described below with reference to FIGS. 2A and 2B. FIG. 8 The rotary device main body 90 includes a plurality of moving devices corresponding to the plurality of toner cartridges 70y to 70k. The trays 80y to 80k can be regarded as components of the moving devices.

[0098] In the present embodiment, the toner cartridge 70k that houses black toner is larger in size and can house more toner than the toner cartridges 70y to 70c that house yellow toner, magenta toner, and cyan toner. In other words, the first toner cartridge can house a first amount of toner, the second toner cartridge can house a second amount of toner, and the first amount can be regarded as being greater than the second amount.

[0099] ​Specifically, the length of the black toner cartridge 70k relative to the rotation axis 90C of the rotary device body 90 in the first radial direction is greater than the length of the magenta toner cartridge 70m in the second radial direction. As used herein, the first radial direction refers to the radial direction of rotation of the toner cartridge 70k relative to the rotary device body 90 extending from the rotation axis 90C when viewed in the direction of the rotation axis 90C (the radial direction of an imaginary circle about the rotation axis 90C). The second radial direction refers to the radial direction of rotation of the toner cartridge 70m relative to the rotary device body 90 extending from 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 greater than the lengths of the other toner cartridges 70y and 70c in the radial directions corresponding to the toner cartridges 70y and 70c.

[0100] Therefore, the tray 80k holding the black toner cartridge 70k is larger than the trays 80y, 80c, and 80k holding the other toner cartridges 70y, 70m, and 70c. That is, the rotary device body 90 includes four toner cartridges 70y to 70k of different sizes and trays 80y to 80k. In other words, 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 smaller than the first toner cartridge, can be detachably attached to the rotary device body 90. Accordingly, the rotary device body 90 includes a tray 80k, as an example of a first support member supporting the first toner cartridge, and a tray 80y, as an example of a second support member smaller than the first support member. Furthermore, toner cartridges 70m and 70c, as examples of third and fourth toner cartridges smaller than the first toner cartridge, can be detachably attached to the rotary device body 90. Accordingly, the rotating device body 90 includes trays 80m and 80c, which are examples of third and fourth support members with dimensions smaller than the first support member.

[0101] Now, refer to FIG. 5 Describes the rotation drive of the main body 90 of the rotary device. For example... FIG. 5 As shown, disc gears 92L and 92R are formed at both ends of the rotary device body 90. Furthermore, rotary device drive gears 93L and 93R are coupled to both ends of the swing shaft 91 in a manner capable of driving transmission. The driving force of the motor M1 is transmitted to the rotary device drive gear 93R through a drive transmission mechanism. Then, the rotary device drive gears 93L and 93R transmit the driving force to the disc gears 92L and 92R, thereby driving the rotary device body 90 to rotate. The rotary device body 90... FIG. 1 It rotates clockwise around the central axis 90C.

[0102] The rotary device body 90 is supported so as to be swingable about the swing axis 91. The rotary device body 90 is biased counterclockwise about the swing axis 91 by a biasing member (not shown) in FIG. 4A and FIG. 4B . This direction can be regarded as a direction in which each of the developing rollers 51y to 51k approaches the photosensitive drum 2. Thus, when the rotary device body 90 assumes the developing orientation, the respective developing rollers 51y to 51k come into contact with the photosensitive drum 2.

[0103] As shown in FIG. 5 , rotary device cams 90eL and 90eR are disposed at both ends of the rotary device body 90. When the rotary device body 90 is rotated clockwise about the rotation axis 90C in FIG. 4A and FIG. 4B , the rotary device cams 90eL and 90eR come into contact with rollers (not shown) supported by the frame 16. Then, the rotary device body 90 is moved clockwise about the swing axis 91 in FIG. 4A and FIG. 4B . This direction can be regarded as a direction in which each of the developing rollers 51y to 51k moves away from the photosensitive drum 2. This direction can also be regarded as a direction in which the rotary device body 90 approaches the opening 16a of the frame 16 and the door 14.

[0104] When the rotary device body 90 is rotated and switched from the developing orientation to the replacement orientation, the rotary device body 90 is thus swung about the swing axis 91. In the replacement orientation of the rotary device body 90, the developing rollers 51 are separated from the photosensitive drum 2.

[0105] As shown in FIG. 4B , in the black replacement orientation, the toner cartridge 70k is stopped at a position opposite the opening 16a formed in the side surface of the device body 1A and the door 14. When the tray 80k is slid from the attached position inside the developing unit 50k to the outside of the rotary device body 90, the user can replace the toner cartridge 70k.

[0106] (Toner cartridge replacement operation)

[0107] The toner cartridge replacement operation will be described with reference to FIG. 4A , FIG. 6A-6C , FIG. 7A , and FIG. 7B . FIG. 6A-6C is an external view of the device body 1A. FIG. 7A and FIG. 7B are cross-sectional views of the vicinity of the rotary device body 90 during the toner cartridge replacement. FIG. 7A and FIG. 7B are cross-sectional views of the image forming apparatus 1 in an imaginary plane perpendicular to the rotation axis 90C of the rotary device body 90.

[0108] FIG. 6A The appearance of the device main body 1A during an image forming operation or in a standby state is illustrated. The image forming operation period refers to a period in which the image forming apparatus 1 performs a series of operations including feeding a sheet S, forming an image on the sheet S, and then discharging the sheet S as a product. The standby state refers to a state in which the image forming apparatus 1 can start an image forming operation upon receiving an image forming instruction (print instruction) and waits for an image forming instruction from a user. As FIG. 6A illustrated in FIG. 1, the door 14 is closed during an image forming operation or in a standby state.

[0109] FIG. 6B The appearance of the device main body 1A during a toner cartridge replacement period is illustrated. During the toner cartridge replacement period, the door 14 is opened, and the tray 80 and the toner cartridge 70 are moved to the outside of the device main body 1A.

[0110] The toner cartridge 70 is movable relative to the developing frame 53 of the developing unit 50 to an attached position and a retracted position in which the toner cartridge 70 is retracted from the attached position. As FIG. 3 illustrated in FIG. 1, the discharge opening 71b and the receiving opening 53b are opposite each other when the toner cartridge 70 is in the attached position. As FIG. 4A and FIG. 4B illustrated in FIG. 1, the rotary device main body 90 is configured to rotate about the rotation axis 90C and assume a developing orientation and a replacement orientation when the toner cartridge 70 is in the attached position.

[0111] A toner cartridge replacement operation will be described. First, a user issues an instruction for a toner cartridge replacement operation to the control unit of the device main body 1A. For example, the user issues the instruction for the toner cartridge replacement operation by inputting via an operation panel (operation unit) disposed on the device main body 1A.

[0112] When the control unit receives the instruction for the toner cartridge replacement operation, the rotary device main body 90 is rotated to a replacement orientation of the toner cartridge 70 to be replaced (the toner in the toner cartridge 70 is used up) and stopped. Specifically, the control unit rotates the rotary device main body 90 to the replacement orientation of the toner cartridge specified by the instruction for the toner cartridge replacement operation (the black replacement orientation for replacing the black toner cartridge 70k in FIG. 4B FIG. 1). In the replacement orientation, the tray 80 supporting the toner cartridge 70 instructed to be replaced is opposite the opening 16a of the frame 16 of the device main body 1A.

[0113] For example, FIG. 4Athe yellow developing roller 51y is opposed to the photosensitive drum 2. Here, the black toner cartridge 70y and the tray 80k do not need to be opposed to the opening 16a or the door 14. In other words, when the rotary device body 90 is in a replacement orientation other than the intended replacement orientation of the toner cartridge 70 or is in a developing orientation, the toner cartridge 70 and the tray 80 do not need to be opposed to the opening 16a or the door 14. Therefore, the opening 16a can have a size large enough for a single toner cartridge 70 to pass through. When the rotary device body 90 is rotated by a predetermined angle from the yellow developing orientation in the drawing clockwise, as shown in FIG. 4B , the black toner cartridge 70k and the tray 80k are opposed to the opening 16a and the door 14.

[0114] As employed herein, "the tray 80 is opposed to the opening 16a" means that the tray 80 is positioned to be movable to the outside of the device body 1A via the opening 16a. More specifically, when the tray 80 is opposed to the opening 16a, the tray 80 can be moved outward in the radial direction of the rotation of the rotary device body 90 by a moving mechanism to be described later, so that the tray 80 and the toner cartridge 70 supported by the tray 80 protrude from the device body 1A. In FIG. 4A , none of the trays 80y to 80k is opposed to the opening 16a. In FIG. 4B , only the black tray 80k is opposed to the opening 16a, and the other trays 80y to 80c are not opposed to the opening 16a.

[0115] In a case where the rotary device body 90 is positioned to the replacement orientation, the motor M2 moves the tray 80 supporting the toner cartridge 70 to be replaced to the outside of the device body 1A.

[0116] Thereby, the toner cartridge 70 to be replaced is moved from the attached position to the retracted position with respect to the rotary device body 90. As shown in FIG. 6B , FIG. 6C , FIG. 7A and FIG. 7B , the tray 80 and the toner cartridge 70 to be replaced supported by the tray 80 protrude from the device body 1A via the opening 16a.

[0117] More specifically, the tray 80 can be moved to a housed position and a detached position with respect to the rotary device body 90. The housed position is a position where the tray 80 is housed within the rotary device body 90. The detached position is a position where the tray 80 protrudes from the rotary device body 90 and the toner cartridge 70 can be detached from the tray 80 (removal position, replaceable position). Examples of the detached position include the position of the tray 80 in FIG. 6B and FIG. 6C , the tray 80k in FIG. 7A , and the tray 80m in FIG. 7B .

[0118] When tray 80 is in the receiving position, the toner cartridge 70 attached to tray 80 is in the attached position. When tray 80 is in the detached position, the toner cartridge 70 attached to tray 80 is in the retracted position.

[0119] The rotary device body 90 includes, not shown, protrusions for holding the tray 80 in a receiving position and the toner cartridge 70 in an attached position. The tray 80 has recesses, not shown, to be engaged with the protrusions. Protrusions and recesses are provided for each of the trays 80y to 80k. The protrusions are desiccated in the direction of engagement with the recesses.

[0120] The protrusion engaging with the recess of the tray 80 locks the tray 80 to the rotating device frame 90f. Thus, even during rotation of the rotating device body 90, the tray 80 remains in the receiving position and prevents the toner cartridge 70 from moving from the attached position. When the tray 80 moves between the receiving and dismounting positions by a mobile device described below, the protrusion can be moved through the tray 80 and disengage from the recess.

[0121] In this embodiment, the door 14 is supported so that it is rotatable relative to the device body 1A. For example... FIG. 7A As shown, door 14 is biased from an open position to a closed position by spring 14s. Spring 14s is, for example, a tension spring, and biases door 14 about its main axis 14c. FIG. 7A and FIG. 7B The counterclockwise torque in the middle.

[0122] Door 14 was pushed open by tray 80. FIG. 6B (The state of the tray 80). This state can be viewed as the tray 80 being supported by the door 14. The door 14 supports at least a portion of the tray 80, which protrudes from the device body 1A, thereby providing more stable support for the toner cartridge 70. In other words, when the first toner cartridge (toner cartridge 70k) is in the first retracted position, the openable and closable member (door 14) in the open position supports the first support member (tray 80k). When the second toner cartridge (toner cartridges 70y to 70c) is in the second retracted position, the openable and closable member (door 14) in the open position supports the second support member (tray 80y to 80c).

[0123] Door 14 is configured to contact a portion of the frame 16 of the device body 1A (e.g., the lower edge 16c of the opening 16a) in the open position and rotate downward beyond the open position. When the tray 80 retracts from the outside of the device body 1A to the inside, door 14 returns to the closed position due to the biasing force of spring 14s.

[0124] The toner cartridge 70 is detachably held by the tray 80. (As...)FIG. 6C As shown in FIG. 6, the user can thus perform an operation of detaching the toner cartridge 70 from the tray 80 and attaching a new toner cartridge 70 (replacement operation). To replace a plurality of toner cartridges 70, the replacement operation can be performed by repeating the foregoing operation.

[0125] FIG. 7A and FIG. 7B A cross section near the rotary device body 90 during replacement of the toner cartridge is illustrated.

[0126] FIG. 7A A state at the time of replacement of the black toner cartridge 70k is illustrated. FIG. 7B A state at the time of replacement of the magenta toner cartridge 70m is illustrated.

[0127] The image forming apparatus 1 includes a moving device not shown for moving the toner cartridge 70 from the attached position to the retracted position. In the present embodiment, the moving device can be regarded as including the tray 80. The moving device including the tray 80k can be regarded as an example of a first moving device including a first support member. The moving device including the tray 80m can be regarded as an example of a second moving device including a second support member.

[0128] Even when the toner cartridge 70 is in the retracted position, the tray 80 remains coupled to (supported by) the rotary device body 90. To facilitate an operation of detaching the toner cartridge 70 from the rotary device body 90, the length by which the toner cartridge 70 protrudes from the rotary device body 90 at the retracted position desirably is large. Since the toner cartridge 70 is configured to be detachably attached to the rotary device body 90 via the tray 80, the toner cartridge 70 can be stably supported by the tray 80 even if the length by which the toner cartridge 70 protrudes from the rotary device body 90 is large.

[0129] The direction of movement of the toner cartridge 70 when the toner cartridge 70 is moved from the attached position to the retracted position will be referred to as a retraction direction. In the present embodiment, the retraction direction of the toner cartridge 70 is a direction intersecting the direction of the rotation axis 90C (Y direction). As FIG. 7A and FIG. 7B As shown in FIG. 6, the retraction direction of the toner cartridge 70 is thus a direction orthogonal to the direction of the rotation axis 90C (Y direction) when viewed in the direction of the rotation axis 90C (Y direction). The retraction direction of the toner cartridge 70 can be regarded as an outward direction (a direction away from the rotation axis 90C) among radial directions of the rotation of the rotary device body 90.

[0130] As FIG. 7A and FIG. 7BAs shown in the middle, in order for the user to perform the operation of detaching the toner cartridge 70 from the rotary device main body 90, at least a portion of the toner cartridge 70 desirably protrudes from the rotary device main body 90 when the toner cartridge 70 is detached. In the present embodiment, when the toner cartridge 70 is in the retracted position, the entire toner cartridge 70 protrudes from the rotary device main body 90.

[0131] When the rotary device main body 90 rotates around the rotation axis 90C, the rotation path of the rotary device main body 90 can be seen as matching a circumscribed circle (not shown, an imaginary circle) of the rotary device main body 90 around the rotation axis 90C. When the toner cartridge 70 is in the retracted position, half or more of the length of the toner cartridge 70 in the retraction direction desirably lies outside the rotation path of the rotary device main body 90. More specifically, when the toner cartridge 70 in the retracted position is viewed in the rotation axis direction of the rotary device, half or more of the entire length of the toner cartridge 70 in the movement direction of the toner cartridge from the attached position to the retracted position desirably lies outside the rotation path of the rotary device. This applies to all of the toner cartridges 70, including the toner cartridge 70k as an example of the first cartridge and the toner cartridge 70m as an example of the second cartridge. In the present embodiment, when the toner cartridge 70 is in the retracted position, the entire toner cartridge 70 lies outside the rotation path (imaginary circle) of the rotary device main body 90.

[0132] In order to facilitate the user’s gripping of the toner cartridge 70, at least a portion of the toner cartridge 70 desirably lies outside the image forming device 1 (outside the device main body 1A) when the toner cartridge 70 is in the retracted position. As employed herein, “outside the device” refers to a space outside the image forming device 1 (outside the device main body 1A) when the image forming device 1 is in use, such as during an image forming operation on the sheet S.

[0133] In the present embodiment, the outer surface of the device main body 1A is constituted by the outer surface of the frame 16. In other words, the outside of the device can be seen as the outside of the frame 16. Therefore, the state in which at least a portion of the toner cartridge 70 lies outside the device can be seen as at least a portion of the toner cartridge 70 protruding from the opening 16a of the frame 16 of the device main body 1A to the outside of the frame 16.

[0134] In the present embodiment, the opening 16a of the frame 16 of the device main body 1A is covered by the door 14 when the door 14 is in the closed position. The outer surface 14a of the door 14 in the closed position constitutes a part of the outer surface of the device main body 1A. In this case, the outside of the device refers to the outside of the outer surface 14a of the door 14 in the closed position. More specifically, in the case where the position of the outer surface 14a of the door 14 in the closed position serves as the outside position, at least a part of the toner cartridge 70 in the retracted position is located outside of the device main body 1A compared to the outside position.

[0135] In other words, if the door 14 is in the open position, at least a part of the toner cartridge 70 is located in the space outside of the device main body 1A. At least a part of the toner cartridge 70 is located downstream of the outside position in the retraction direction of the toner cartridge 70.

[0136] In the case where the side surface where the opening 16a is located serves as the front face of the device main body 1A, at least a part of the toner cartridge 70 in the retracted position can be regarded as protruding forward from the outer surface of the device main body 1A from the front face side. In this case, the user can easily access the toner cartridge 70 from the front face side of the image forming device 1 and perform the replacement operation of the toner cartridge 70.

[0137] When the toner cartridge 70 is in the retracted position, half or more of the length of the toner cartridge 70 in the retraction direction desirably is located outside of the device. More specifically, when viewed in the direction of the rotation axis of the rotary device, half or more of the entire length of the toner cartridge 70 in the direction of movement of the toner cartridge 70 from the attached position to the retracted position desirably is located outside of the main body frame when the toner cartridge 70 is in the retracted position. This applies to all of the toner cartridges 70, including the toner cartridge 70k as an example of the first cartridge and the toner cartridge 70m as an example of the second cartridge. The entire toner cartridge 70 more desirably is located outside of the device when the toner cartridge 70 is in the retracted position. In the present embodiment, the outer surface of the device main body 1A on the front face side is constituted by the outer surface 14a of the door 14 and the side surface. However, the configuration of the door 14 is not limited thereto. For example, the door 14 can have a size that covers the entire side surface. In this case, the outer surface of the device main body 1A on the front face side is constituted by the outer surface 14a of the door 14.

[0138] The tray 80 includes a cartridge holding portion 81 (see FIG. 3 and FIG. 6C ) that holds the toner cartridge 70. The cartridge holding portion 81 is a portion to be attached where the toner cartridge 70 is attached. When the tray 80 is in the detached position, the entire cartridge holding portion 81 desirably is located outside of the rotation path of the rotary device main body 90 in the retraction direction. When the tray 80 is in the detached position, half or more of the length of the cartridge holding portion 81 in the retraction direction desirably is located outside of the device.

[0139] As described above, the size of the toner cartridge 70k and the tray 80k is larger than those of the other toner cartridges 70y to 70c and the trays 80y to 80c. As FIG. 7A and FIG. 7B In the present embodiment, as shown in

[0140] Specifically, as shown in FIG. 7A the moving distance of the tray 80k (first support member) when moving from the housing position (first housing position) to the detachment position (first detachment position) is LI. The moving distance of the tray 80m (second support member) when moving from the housing position (second housing position) to the detachment position (second detachment position) is L2. FIG. 7B The state in which the toner cartridge 70m and the tray 80m move is illustrated. The moving distance when the trays 80y and 80c move from the housing position to the detachment position is also L2. Here, LI is larger than L2. In other words, the moving distance of the first support member when the first toner cartridge moves from the first attachment position to the first retracted position can be considered to be larger than the moving distance of the second support member when the second toner cartridge moves from the second attachment position to the second retracted position.

[0141] As shown in FIG. 7A In a case where the tray 80k is in the detachment position and the toner cartridge 70k is in the retracted position, the toner cartridge 70k protrudes from the outer surface of the device main body 1A toward the outside of the device by a distance PI. In the present embodiment, the tray 80k also protrudes from the outer surface of the device main body 1A toward the outside of the device by the distance PI.

[0142] As shown in FIG. 7B In a case where the tray 80m is in the detachment position and the toner cartridge 70m is in the retracted position, the toner cartridge 70m protrudes from the outer surface of the device main body 1A toward the outside of the device by a distance P2. In the present embodiment, the tray 80m also protrudes from the outer surface of the device main body 1A toward the outside of the device by the distance P2. The toner cartridges 70y and 70c also protrude from the outer surface of the device main body 1A toward the outside of the device by the distance P2.

[0143] The distance PI is larger than the distance P2. In other words, assuming that the protruding length of the first toner cartridge in the first retracted position from the opening 16a of the device main body 1A is a first length (PI), and the protruding length of the second toner cartridge in the second retracted position from the opening 16a is a second length (P2). In this case, the first length can be considered to be larger than the second length.

[0144] In terms of strength, the toner cartridges 70y to 70c, which are smaller in size than the toner cartridge 70k, desirably have a distance P2 by which they protrude to the outside of the device at the retracted position that is smaller than a distance P1 by which the toner cartridge 70k protrudes to the outside of the device at the retracted position. The reason is as follows. When the toner cartridge 70 is located at the retracted position, at least a portion of the toner cartridge 70 protrudes to the outside of the rotating path of the rotating device body 90 or protrudes to the outside of the device from the outer surface of the device body 1A. Here, the tray 80 supports the weight of the toner cartridge 70 in a state in which the tray 80 is cantilevered on the rotating device body 90. Therefore, by reducing the distance P2 by as much as the toner cartridges 70y to 70c protrude to the outside of the device at the retracted position, it is possible to reduce the load on the tray 80y to 80c and the guide unit (not shown) of the rotating device body 90 for supporting the tray 80y to 80c. Also, the toner cartridges 70y to 70c are smaller in size than the toner cartridge 70k, and even if the distance P2 is made smaller than the distance P1, it is possible to maintain the operability of the cartridge replacement on the tray 80y to 80c.

[0145] (tray layout in rotating device)

[0146] The layout of the trays 80y to 80k in the rotating device body 90 will be described with reference to FIG. 8 , FIG. 9 and FIG. 10 . FIG. 8 is a perspective view that illustrates the layout of the trays 80y to 80k in the rotating device body 90. FIG. 9 is a cross-sectional view that illustrates the layout of the trays 80y to 80k in the rotating device body 90. FIG. 10 is a view that illustrates the arrangement of members on one end side of the trays 80y to 80k in the Y direction. FIG. 9 illustrates a cross section of the rotating device body 90 in an imaginary plane that is perpendicular to the rotation axis 90C of the rotating device body 90. FIG. 10 The upper half of FIG. 8 is a view of the rotating device body 90 and the trays 80m and 80k as seen from the upper right (+Z side) of FIG. 10 The lower half of FIG. 8 is a view of the rotating device body 90 and the trays 80c and 80y as seen from the left side (-X side) of

[0147] As shown in FIG. 8 , the trays 80y to 80k each include a cartridge holding unit 81y to 81k and a to-be-guided portion 82y to 82k.

[0148] The toner cartridges 70y to 70k are attached to the cartridge holding portions 81y to 81k, respectively. The cartridge holding portions 81y to 81k accommodate at least a portion of the respective toner cartridges 70y to 70k attached thereto.

[0149] The to-be-guided portions 82y to 82k are located at both ends of the trays 80y to 80k in the Y direction, with the cartridge holding portions 81y to 81k therebetween. Each of the to-be-guided portions 82y to 82k is an elongated member extending in a direction orthogonal to the rotation axis of the rotary device body 90.

[0150] In the present embodiment, a reinforcing rib (not shown) is formed on a portion of each to-be-guided portion 82k in the moving direction of the tray 80k, and a reinforcing rib (not shown) is formed on a portion of each to-be-guided portion 82m in the moving direction of the tray 80m (see also FIG. 11A and FIG. 11B ). The reinforcing ribs are rib shapes (ridges) protruding outward in the Y direction from the to-be-guided portions 82k and 82m located at both ends of the trays 80k and 80m in the Y direction, and extend long in the moving direction of the trays 80k and 80m. The reinforcing ribs improve the rigidity of the to-be-guided portions 82k and 82m.

[0151] In the present embodiment, the reinforcing ribs have a limited length to avoid interfering with the to-be-guided portions 82y and 82c. However, in the absence of the possibility of interference with the to-be-guided portions 82y and 82c, the reinforcing ribs can be deployed over the entire length of the to-be-guided portions 82m and 82k. The reinforcing ribs can also be added to the to-be-guided portions 82y and 82c. If the to-be-guided portions 82m and 82k have sufficient rigidity, the reinforcing ribs can be omitted.

[0152] Rack portions 83y to 83k (rack gears) are formed on the to-be-guided portions 82y to 82k. Pinions 94y to 94k are rotatably held inside the rotary device body 90. The pinions 94y to 94k are engaged with the rack portions 83y to 83k, respectively, in a drivable manner.

[0153] The rack portions 83y to 83k and the pinions 94y to 94k are components of a moving device configured to move the toner cartridges 70y to 70k from the attached position to the retracted position. The rack portions 83y to 83k and the pinions 94y to 94k can be regarded as components of a to-be-driven device to be driven by a driving device of the device body 1A.

[0154] The pinions 94y to 94k can be regarded as rotors (rotating members) that rotate to move the trays 80y to 80k relative to the rotary device body 90.

[0155] Pinions 94y to 94k and rack portions 83y to 83k serve as driven portions of a mobile device for a rotary device body 90, receiving driving force from a drive device of the device body 1A. Pinions 94k and rack portions 83k are examples of a first pinion and a first rack gear constituting at least a part of a first driven unit included in a first drive device. Pinions 94m and rack portions 83m are examples of a second pinion and a second rack gear constituting at least a part of a second driven unit included in a second mobile device.

[0156] The rotary device body 90 includes a guide portion to engage with the portions 82y to 82k to be guided. The rotary device body 90 also includes similar guide portions to engage with the portions 82y and 82c to be guided on trays 80y and 80c. The guide portions are located not only on one side (+Y side) of the rotary device body 90 in the Y direction, but also on the other side (-Y side) of the rotary device body 90 in the Y direction.

[0157] As the tray 80 moves between the receiving position and the disassembly position, the guide portion maintains engagement with the portion 82 to be guided and guides the movement direction of the tray 80 for at least a portion of the movement range. In this embodiment, the guide portion maintains engagement with the portion 82 to be guided throughout the entire movement range between the receiving and disassembly positions of the tray 80k. In this embodiment, the guide portion maintains engagement with the portion 82 to be guided throughout the entire movement range between the receiving and disassembly positions of the tray 80m.

[0158] like FIG. 8 and FIG. 9 As shown in the diagram, and as will be described in detail below, four trays 80y to 80k are arranged to overlap each other in the rotating device body 90.

[0159] As the pinion gears 94y to 94k rotate, the rack portions 83y to 83k and the trays 80y to 80k move relative to the main body 90 of the rotating device. FIG. 9 As shown, four trays 80y to 80k are arranged such that their direction of movement rotates relative to the rotating device body 90 in units of 90°. Trays 80y and 80c, as well as trays 80m and 80k, are thus held to slide in substantially the same direction (parallel direction). This direction of movement of trays 80y to 80k during sliding movement is limited by the engagement of the aforementioned guide portions 82y to 82y with the guide portion.

[0160] Trays 80y to 80k move to the outside of the device through opening 16a. The direction of movement of each of trays 80y to 80k from opening 16a to the outside of the device is substantially the same (parallel).

[0161] likeFIG. 9 As shown in FIG. 8, in the moving direction of the tray 80k, the range in which the tray 80k is present is arranged to overlap with the range in which the tray 80y is present and the range in which the tray 80c is present. In the moving direction of the tray 80k, the range in which the tray 80k is present also overlaps with the rotation axis 90C of the rotary device main body 90. In other words, the toner cartridge 70k held by the cartridge holding portion 81k of the tray 80k can be regarded as overlapping with the rotation axis 90C of the rotary device main body 90 (in the direction of the rotation axis of the rotary device). FIG. 4B ).

[0162] In the moving direction of the tray 80m, the range in which the tray 80m is present is offset so as not to overlap with the range in which the tray 80y is present or the range in which the tray 80c is present. In the moving direction of the tray 80y, the range in which the tray 80y is present is offset so as not to overlap with the range in which the tray 80m is present or the range in which the tray 80k is present. Similarly, in the moving direction of the tray 80c, the range in which the tray 80c is present is offset so as not to overlap with the range in which the tray 80m is present or the range in which the tray 80k is present.

[0163] The positional relationship between the trays 80 can also be expressed as follows: when viewed in the moving direction of the tray 80y, the tray 80y overlaps with the tray 80k, and the tray 80y does not overlap with the tray 80m. When viewed in the moving direction of the tray 80m, the tray 80m overlaps with the tray 80k, and the tray 80m does not overlap with the trays 80y and 80c. When viewed in the moving direction of the tray 80c, the tray 80c overlaps with the tray 80k, and the tray 80c does not overlap with the tray 80m.

[0164] As employed herein, two elements (members, components, units, etc.) overlap when viewed in a particular direction means that when the elements are projected perpendicularly onto an imaginary plane perpendicular to that direction, the projected area of one of the elements at least partially overlaps with the projected area of the other.

[0165] As FIG. 8 and FIG. 10 shown in FIG. 8, in the direction of the rotation axis 90C (Y direction), the range in which the rack portion 83m and the to-be-guided portion 82m are present at least partially overlaps with the range in which the rack portion 83k and the to-be-guided portion 82k are present. In other words, in the present embodiment, the range in which the first rack gear (rack portion 83k) is present can be regarded as at least partially overlapping with the range in which the second rack gear (rack portion 83m) is present in the direction of the rotation axis of the rotary device (Y direction). The rack portions 83m and 83k and the to-be-guided portions 82m and 82k can thus be arranged in the Y direction in a space-saving manner, as compared with a configuration in which the rack portion 83m and the to-be-guided portion 82m do not overlap with the rack portion 83k or the to-be-guided portion 82k.

[0166] In the direction of the rotation axis 90C (Y direction), the range in which the rack portion 83y and the to-be-guided portion 82y are present at least partially overlaps the range in which the rack portion 83c and the to-be-guided portion 82c are present. In other words, in the present embodiment, the range in which the third rack gear (third rack portion 83y) is present at least partially overlaps the range in which the fourth rack gear (rack portion 83c) is present in the direction of the rotation axis of the rotary device (Y direction). The rack portions 83y and 83c and the to-be-guided portions 82y and 82c can be arranged in the Y direction in a space-saving manner compared to an arrangement in which the rack portion 83y and the to-be-guided portion 82y do not overlap the rack portion 83c or the to-be-guided portion 82c.

[0167] Now, the FIG. 10 engagement positions of the rack portions 83 and the pinions 94 will be described. FIG. 10 The upper half of FIG. 6 illustrates the engagement position of the rack portion 83k and the pinion 94k. FIG. 10 The lower half of FIG. 6 illustrates the engagement position of the rack portion 83y and the pinion 94y.

[0168] The drive force transmitted from the motor M2 (M2) that serves as a drive source is transmitted to the pinions 94y to 94k in the region Y1 in the drawing in the direction of the rotation axis 90C of the rotary device main body 90 (Y direction) via a transmission device that will be described later. FIG. 2 The pinion 94k engages with the rack portion 83k in the region Y2 in the drawing in the Y direction in a drive-transmittable manner. The rack portion 83m engages with the pinion 94m (M2) in the region Y2 in the Y direction in a drive-transmittable manner, just like the rack portion 83k. FIG. 8 The rack portion 83c engages with the pinion 94c (M2) in the region Y3 in the Y direction in a drive-transmittable manner, just like the rack portion 83y. FIG. 8

[0169] Here, the regions Y2 and Y3 are located at different positions in the Y direction (offset in the Y direction). The region Y1 is located at a position different from both the regions Y2 and Y3 in the Y direction. In other words, the region Y1 is offset from the regions Y2 and Y3 in the Y direction.

[0170] ​When the toner cartridges 70y and 70c are in the attached position, the areas occupied by the rack portion 83y and the rack portion 83c at least partially overlap in the direction of movement of the rack portion 83y (the direction of movement of the tray 80y). In this embodiment, the directions of movement of the trays 80y and 80c are substantially the same (parallel), therefore the areas occupied by the rack portion 83y and the rack portion 83c also at least partially overlap in the direction of movement of the tray 80c. When the toner cartridges 70y and 70c are in the attached position, the tooth surfaces of the rack portion 83y and the rack portion 83c are in a direction orthogonal to the direction of movement of the rack portions 83y and 83c (…). FIG. 8 They are opposite each other in the horizontal direction.

[0171] When the toner cartridges 70m and 70k are in the attached position, the area occupied by the rack portion 83m and the area occupied by the rack portion 83k at least partially overlap in the direction of movement of the rack portion 83m (the direction of movement of the tray 80m). In this embodiment, the directions of movement of the trays 80m and 80k are substantially the same (parallel), therefore the areas occupied by the rack portion 83m and the areas occupied by the rack portion 83k also at least partially overlap in the direction of movement of the tray 80k. When the toner cartridges 70m and 70k are in the attached position, the tooth surfaces of the rack portion 83m and the rack portion 83k are in a direction orthogonal to the direction of movement of the rack portions 83m and 83k (…). FIG. 8 They are opposite each other in the vertical direction.

[0172] As will be described later FIG. 12A As shown, when viewed in the direction of rotation axis 90C (Y direction), rack portion 83y overlaps with rack portions 83m and 83k. When viewed in the direction of rotation axis 90C (Y direction), rack portion 83m overlaps with rack portions 83y and 83c. When viewed in the direction of rotation axis 90C (Y direction), rack portion 83c overlaps with rack portions 83m and 83k. When viewed in the direction of rotation axis 90C (Y direction), rack portion 83k overlaps with rack portions 83y and 83c. In other words, the area occupied by the first rack gear (rack portion 83k) and the area occupied by the second rack gear (rack portion 83m) can be considered as not overlapping in the direction of rotation axis (Y direction) of the rotary device. When the first toner cartridge 70k is in the first attachment position and the second toner cartridge 70y is in the second attachment position, the first rack gear (rack portion 83k) and the second rack gear (rack portion 83y) can be considered to overlap when viewed in the rotation axis direction (Y direction) of the rotary device.

[0173] Therefore, since the positions of the rack portions 83k and 83m are different from the positions of the rack portions 83y and 83c in the Y direction, the rack portions 83y and 83c can be arranged to overlap the rack portions 83m and 83k when viewed in the Y direction.

[0174] This can save space for arranging four trays in the rotary device body 90 and miniaturize the rotary device body 90 in the radial direction of rotation. If the moving distances of the respective trays 80y to 80k are maintained the same as the moving distances in the present embodiment, the area required for arranging four pairs of rack portions when viewed in the Y direction increases when the rack portions 83 are arranged not to overlap each other when viewed in the Y direction. In comparison with such a configuration, arranging the plurality of pairs of rack portions 83 at positions offset in the Y direction so that the rack portions 83 overlap when viewed in the Y direction can reduce the area for arranging the rack portions 83 when viewed in the Y direction.

[0175] In the present embodiment, the positions of the four pairs of rack portions 83y to 83k in the Y direction are offset in two groups of two pairs. In other words, in the direction of the rotation axis of the rotary device (Y direction), the range in which the first rack gear is present can be seen as overlapping the range in which the second rack gear is present, and the range in which the third rack gear is present can be seen as overlapping the range in which the fourth rack gear is present. Also, in the Y direction, the range in which the first rack gear and the second rack gear are present can be seen as being arranged not to overlap the range in which the third rack gear and the fourth rack gear are present. This allows the rotary device body 90 to be miniaturized in the Y direction in comparison with the case where the four pairs of rack portions 83y to 83k are located at different positions in the Y direction.

[0176] (Moving configuration of trays)

[0177] The configuration related to the movement of the trays 80y to 80k arranged in the rotary device body 90 will be described with reference to FIG. 11A , FIG. 11B , FIG. 12A and FIG. 12B . FIG. 11A and FIG. 11B are perspective views illustrating the configuration related to the movement of the tray 80k. FIG. 12A and FIG. 12B are cross-sectional views illustrating the configuration related to the movement of the tray 80k.

[0178] In the present embodiment, all of the trays 80y to 80k are driven by the driving force of the motor M2 via the drive racks 15L and 15R as transmission devices to the pinions 94y to 94k. Here, the configuration for moving the tray 80k with respect to the rotary device body 90 will be described. The configuration for driving the trays 80y to 80c with respect to the rotary device body 90 is substantially the same as the configuration for driving the tray 80k, and thus the description thereof will be omitted.

[0179] FIG. 11A A state in which the tray 80k is located inside the rotary device body 90 (i.e., a state in which the toner cartridge 70k is attached to the developing unit 50k) is illustrated. In other words, FIG. 11A A state in which the tray 80k is in the accommodation position, which corresponds to a state in which the toner cartridge 70k is in the detached position with respect to the developing frame 53k ( FIG. 4A ) is illustrated. FIG. 11B A state in which the tray 80k is slid out of the rotary device body 90 is illustrated. In other words, FIG. 11B A state in which the tray 80k is located at the attachment position, which corresponds to a state in which the toner cartridge 70k is in the retracted position with respect to the developing frame 53k ( FIG. 4B ) is illustrated.

[0180] The device body 1A according to the present embodiment includes the drive racks 15L and 15R as drive gears for driving the pinions 94. Each drive rack 15 is driven by the motor M2 via a drive transmission mechanism, which is not shown.

[0181] As described above, two rack portions 83k are formed at both ends of the tray 80k in the Y direction. Two pinions 94k and two drive racks 15L and 15R are disposed at positions corresponding to the rack portions 83k on both ends. In other words, the device body 1A according to the present embodiment includes the drive racks 15L and 15R as a first drive gear and a second drive gear. The drive rack 15L can be regarded as an example of the first drive gear, and the drive rack 15R can be regarded as an example of the second drive gear.

[0182] Note that such numbering is used only for the convenience of description, and in principle, can be appropriately interchanged. When it is not necessary to distinguish, the drive racks 15L and 15R will be referred to as "drive racks 15".

[0183] The rack portion 83 according to the present embodiment is configured as a rack-and-pinion pair, and the pinion 94 according to the present embodiment is configured as a pinion pair. In the present embodiment, the rack-and-pinion pair and the pinion pair are located at one end side and the other end side of the support member (tray 80) in the Y direction, but can be located at other positions. The rack portion 83k and the pinion 94k of the mobile device corresponding to the tray 80k can be respectively regarded as examples of a first rack-and-pinion pair and a first pinion pair.

[0184] The rack portions 83y to 83c and the pinions 94y to 94c of the mobile device corresponding to the respective other trays 80y to 80c can be respectively regarded as examples of a second rack pair and a second pinion pair.

[0185] One of the rack-and-pinion pairs meshes with one of the pinion pairs, and the other of the rack-and-pinion pairs meshes with the other of the pinion pairs. At least one of the pinion pairs is driven by the drive rack 15L serving as the first drive rack. In the present embodiment, the pinion pairs are simultaneously driven by both the drive racks 15L and 15R serving as the first drive rack and the second drive rack. This suppresses rotation of the tray 80 and enables stable movement of the toner cartridge 70.

[0186] The tray 80 can be configured to have one rack portion 83 and be moved by one drive rack 15 via one pinion 94.

[0187] The tray 80k is held so as to be slidable with respect to the rotary device main body 90 in a direction parallel to the to-be-guided portion 82k, that is, a direction of movement. The drive rack 15 is held so as to be slidable with respect to the device main body 1A in a direction intersecting the direction of movement of the tray 80k. The drive rack 15 is configured to slide (reciprocate) with respect to the device main body 1A in a first direction (vertically upward in the present embodiment) and a second direction opposite to the first direction (vertically downward in the present embodiment). In other words, the direction of movement of the drive rack 15 according to the present embodiment is a direction intersecting (desirably orthogonal to) both the direction of movement of the tray 80k and the direction of the rotation axis 90C of the rotary device main body 90 (Y direction).

[0188] The tray moving operation for sliding the tray 80k between the accommodation position and the detached position will be described with reference to FIG. 11A and FIG. 11B The tray moving 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 94k, and the rack portion 83k.

[0189] The tray moving operation when the toner cartridge 70k is detached from the rotary device body 90 (tray pull-out operation) will be described first. In a state before the start of the tray pull-out operation, the drive rack 15 is located below the position where the pinion 94k is engaged ( FIG. 11A ). As described above, during the replacement operation of the toner cartridge 70k, the rotary device body 90 assumes a replacement orientation for the toner cartridge 70k ( FIG. 4B ).

[0190] When the tray pull-out operation is started, the drive rack 15 is slid upward with respect to the device body 1A by the driving force of the motor M2. During the movement, the drive rack 15 is engaged with the pinion 94k, and the pinion 94k is driven to rotate.

[0191] As shown in FIG. 11B , the pinion 94k is driven to rotate in the direction of the arrow in the drawing, so that a driving force is input to the rack portion 83k engaged with the pinion 94k. The tray 80k is thereby pushed out to the outside of the device, moving from the housed position to the detached position with respect to the rotary device body 90. Here, the moving direction of the tray 80k is guided to a predetermined moving direction by the engagement of the to-be-guided portion 82k with the guide portion of the rotary device body 90. As a result of the movement of the tray 80k from the housed position to the detached position, the toner cartridge 70k moves from the attached position to the retracted position with respect to the developing unit 50k.

[0192] When the tray 80k is located at the detached position and the toner cartridge 70k is located at the retracted position, the user can detach or attach the toner cartridge 70k from / to the tray 80k.

[0193] The tray moving operation when the toner cartridge 70 is attached to the rotary device body 90 (tray pull-in operation, tray insertion operation) is performed in a process opposite to the tray pull-out operation. For example, the user operates a predetermined operation unit to start the tray pull-in operation. When the tray pull-in operation is started, the drive rack 15 is slid downward with respect to the device body 1A by the driving force of the motor M2. The rotation direction of the motor M2 in the tray pull-in operation is opposite to that in the tray pull-out operation.

[0194] The pinion 94K is driven to rotate in a direction opposite to the arrow in FIG. 11B , so that a driving force is input to the rack portion 83k engaged with the pinion 94k. Thereby, the tray 80k is pulled in to the inside of the device, moving from the detached position to the housed position with respect to the rotary device body 90.

[0195] The moving direction of the tray 80k is guided to the moving direction (opposite to FIG. 11BThe arrow in the drawing is reversed). As a result of the tray 80k moving from the detached position to the housed position, the toner cartridge 70k moves from the retracted position to the attached position relative to the developing unit 50k.

[0196] While the movement of the black tray 80k and the toner cartridge 70k has been described above, the other trays 80y to 80c and the toner cartridges 70y to 70c are also moved by similar mechanisms. That is, in the replacement direction of each toner cartridge, the drive rack 15 transmits the drive to the pinions 94y to 94c.

[0197] The drive device for driving the moving devices disposed in the rotary device body 90 is constituted by the motor M2 included in the device body 1A and a transmission device including the drive rack 15 (15L and 15R) and a drive transmission mechanism.

[0198] As described above, in the present embodiment, the rotary device body 90 includes a plurality of moving devices corresponding to the plurality of toner cartridges 70k to 70y. The drive device of the device body 1A is a common drive device that drives the plurality of moving devices (a plurality of devices to be driven) of the rotary device body 90.

[0199] In the present embodiment, the drive device switches its drive target in accordance with the rotation of the rotary device body 90. The drive device according to the present embodiment includes the drive rack 15 that functions as a transmission member for transmitting the drive force of the drive source. The drive device can assume a state in which the transmission member is engaged with the first device to be driven (the pinion 94k) in a manner capable of driving transmission and a state in which the transmission member is engaged with the second device to be driven (the pinion 94m) in a manner capable of driving transmission. The drive device can also assume a state in which the transmission member is disengaged from the first device to be driven and the second device to be driven.

[0200] As described above, the pinions 94y to 94k are held by the rotary device body 90. Therefore, when the rotary device body 90 rotates, the pinions 94y to 94k desirably disengage from each other from the drive rack 15.

[0201] FIG. 12A A state in which the tray 80k is located inside the rotary device body 90 (located in the housed position) is illustrated. FIG. 12B A state in which the tray 80k is moved to the outside of the rotary device body 90 (moved to the detached position) is illustrated.

[0202] As FIG. 12A As shown in the drawing, when the tray 80k is located inside the rotary device body 90, the drive rack 15 is located in the lower portion of the device body 1A. Here, the drive rack 15 is retracted from the pinions 94. Therefore, the rotary device body 90 can be rotated without interfering with the drive rack 15. More specifically, the drive rack 15 can be retracted from the pinions 94 in accordance with the rotation of the rotary device body 90.FIG. 12A and FIG. 12B outside the rotation path of the rotary device body 90 indicated by the dotted line in

[0203] As described above, by driving the motor M2 forward and backward, the trays 80 attached to the rotary device body 90 can be moved relative to the rotary device body 90 from the accommodation position to the detachment position and from the detachment position to the accommodation position. In other words, the driving apparatus according to the present embodiment can not only drive each of the moving apparatuses of the rotary device so that the toner cartridge 70 moves from the attached position to the retracted position, but also drive each of the moving apparatuses so that the toner cartridge 70 moves from the retracted position to the attached position.

[0204] As described above, in the present embodiment, the amount of movement of the trays 80 during the toner cartridge replacement varies depending on the size of the toner cartridge 70. Specifically, as FIG. 7A and FIG. 7B indicated in

[0205] In the present embodiment, when the toner cartridges 70y to 70k are moved from their attached positions to their retracted positions, the amount obtained by dividing the speed of the rack portion 83k by the speed of the driving rack 15 is greater than the amount obtained by dividing the speed of the rack portions 83y to 83c by the speed of the driving rack 15.

[0206] For example, as indicated in FIG. 10 , the pinion 94y is configured as a stepped gear so that the pitch circle radius of the small-diameter gear 942 engaged with the rack portion 83y is smaller than the pitch circle radius of the large-diameter gear 941 engaged with the driving rack 15. The pinions 94m and 94c are configured as similar stepped gears. On the other hand, the pinion 94k is configured to have the same pitch circle radius at the engagement portion with the driving rack 15 and at the engagement portion with the rack portion 83k. Here, the pitch circle radius of the pinion 94k can be the same as the pitch circle radius of the large-diameter gear 941 of the pinions 94y to 94c. With this configuration, for the same movement distance of the driving rack 15, it is possible to make the movement distance of the rack portion 83k greater than the movement distance of the other rack portions 83y to 83c. More specifically, it is possible to make the movement distance LI when the black tray 80k is moved from the accommodation position to the detachment position greater than the movement distance L2 when the other trays 80y to 80c are moved from their accommodation positions to their detachment positions.

[0207] Since pinion gears 94y to 94c are configured as stepped gears, the moving distance LI of the tray 80k can be made larger than the moving distance L2 of the other trays 80y to 80c, despite the configuration in which the pinion gears 94y to 94k receive driving force from the same driving rack 15.

[0208] Instead of (or in combination with) configuring the pinion gears 94y to 94c as stepped gears, the pinion gear 94k can be configured as a stepped gear. In this case, the portion of the pinion gear 94k that engages with the rack portion 83k can be configured as a small-diameter gear and the portion of the pinion gear 94k that engages with the rack portion 83k can be configured as a large-diameter gear having a pitch circle radius larger than that of the small-diameter gear. Stepped gears are an example of a reduction mechanism, and other conventional reduction mechanisms that reduce the amount of movement of the output side (tray 80 side) member compared to the amount of movement of the input side (driving source side) member can be used instead.

[0209] The amount of movement of the driving rack 15 when moving the toner cartridge 70k from the attached position to the retracted position can be made larger than the amount of movement of the driving rack 15 when moving the toner cartridges 70y to 70c from their attached positions to their retracted positions.

[0210] The shorter the distance by which the toner cartridge 70 moves from the attached 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 waits for the toner cartridge 70 to move. The configuration in which the amount of movement of the driving rack 15 with respect to the toner cartridge 70k is larger than the amount of movement of the driving rack 15 with respect to the toner cartridges 70y to 70c as described above can reduce the time the user waits for the toner cartridges 70y to 70c to move.

[0211] The above-described configurations can make the moving distance LI larger than the moving distance L2. These configurations can be used in combination.

[0212] (Modified Example)

[0213] Although the portion to be driven is described as including a pinion gear 94 that engages with both the driving rack 15 and the rack portion 83, the portion to be driven can include a gear that engages with the driving rack 15 and a gear that engages with the rack portion 83.

[0214] The configuration of the moving device for moving the tray 80 is also not limited to the rack and gear configuration. For example, the member corresponding to the pinion gear 94 can be replaced with a roller to be rotated by the motor M2, and the tray 80 can be moved by the frictional force between the roller and the tray 80.

[0215] When a roller to be rotated by the motor M2 is used, the roller can be brought into contact with the toner cartridges 70. In this case, the toner cartridges 70y to 70k can be configured to be detachable and attachable directly from the rotary device body 90 without intervention of the trays 80y to 80k. In this case, the driving device can be constituted by the roller.

[0216] (Configuration for detecting a remaining toner level in a developing housing portion)

[0217] A configuration for detecting a remaining level of toner in the developing frame 53 of the image forming apparatus 1 according to the first embodiment will be described with reference to FIGS. 13-2 0. A configuration for detecting a remaining level of toner in the developing frame 53 of the image forming apparatus 1 according to the first embodiment will be described with reference to

[0218] The amount of toner in the toner cartridges 70 decreases each time an image forming operation is performed. If the toner level in the toner cartridges 70 is low, less toner is supplied from the toner cartridges 70 to the developing frame 53. Therefore, the remaining toner level in the developing frame 53 decreases. If image formation is performed with the remaining toner level in the developing frame 53 being low, image defects can occur on a printed product. Therefore, the image forming apparatus 1 according to the present embodiment includes a configuration for detecting a remaining toner level in the developing frame 53.

[0219] By detecting that the remaining toner level in the developing frame 53 is low, it can be detected that the remaining toner level in the toner cartridges 70 is low. When it is detected that the amount of toner in any of the toner cartridges 70 is insufficient, the image forming apparatus 1 can thus issue a notification to replace the toner cartridges 70.

[0220] A configuration for detecting a remaining level in the developing frame 53 will be described with reference to FIG. 1 and FIG. 13 A configuration for detecting a remaining level in the developing frame 53 will be described with reference to FIG. 13 is a plan view of the rotary device. As shown in FIG. 13 , the developing units 50y, 50m, 50c, and 50k include the developing frames 53y, 53m, 53c, and 53k, respectively. The magnet units 103y, 103m, 103c, and 103k are disposed inside the developing frames 53y, 53m, 53c, and 53k, respectively. In other words, the developing frames 53 can be regarded as including the magnet units 103. The developing units 50y, 50m, 50c, and 50k can also be regarded as including the magnet units 103y, 103m, 103c, and 103k, respectively.

[0221] The magnet units 103y, 103m, 103c, and 103k have a common configuration and function. Therefore, when it is not necessary to distinguish, a suffix y, m, c, and k will be omitted to describe one of the four magnet units 103.

[0222] As shown in FIG. 1and FIG. 13 As shown, a magnetic sensor 102 is deployed above the rotating device body 90. The magnetic sensor 102 is a detection unit for detecting the magnetic poles generated by the magnet 101. The magnetic sensor 102 is located above the upper end 90eu of the rotating device, which is the vertical uppermost point of the rotating device body 90. In the following description, the center of rotation of the rotating device body 90 will be referred to as the rotating device center Rm. The magnetic sensor 102 is located above the rotating device center Rm. The magnetic sensor 102 is opposite to the rotating device body 90.

[0223] like FIG. 1 As shown, the magnetic sensor 102 is located downstream of the intermediate transfer belt 10a in the retraction direction of the toner cartridge 70. The magnetic sensor 102 is also located downstream of the photosensitive drum 2a in the retraction direction (X direction) of the toner cartridge 70.

[0224] Next, we will refer to FIG. 13 , FIG. 14A and FIG. 14B Describe magnet unit 103. FIG. 14A This is a perspective view of magnet unit 103. FIG. 14B This is a plan view of the magnet unit 103. In the following description, the direction from the center Rm of the rotary device to the outside of the rotary device in the radial direction of rotation of the rotary device body 90 will be referred to as the first radial direction. The downstream end of the developing frame 53 in the first radial direction will be referred to as the downstream end 53rd of the receiving portion, and the upstream end will be referred to as the upstream end 53ru of the receiving portion. In the first radial direction, the distance between the upstream end 53ru of the receiving portion and the center Rm of the rotary device is less than the distance between the downstream end 53rd of the receiving portion and the center Rm of the rotary device. The downstream end 53rd of the receiving portion and the upstream end 53ru of the receiving portion are opposite each other in the first radial direction. The downstream end 53rd of the receiving portion and the upstream end 53ru of the receiving portion extend in a direction intersecting the first radial direction.

[0225] like FIG. 14A As shown, the magnet unit 103 is supported by the developing frame 53. More specifically, the magnet unit 103 is supported on the downstream end 53rd of the receiving portion. The developing frame 53 houses the fixing member 107 and the magnet unit 103. In other words, the developing frame 53 can be viewed as including the fixing member 107 and the magnet unit 103. The magnet unit 103 includes a magnet 101, a support member 100, and a rotation shaft 106. The fixing member 107 is integrated with the developing frame 53 and fixes the rotation shaft 106 to the developing frame 53. The rotation shaft 106 is rotatably fixed to the fixing member 107. In other words, the rotation shaft 106 can be viewed as a unit to be supported by the developing frame 53 via the fixing member 107.

[0226] The support member 100 is integrated with the rotation shaft 106. In other words, the support member 100 is fixed to the fixed member 107. The support member 100 can rotate with the rotation shaft 106 as a rotation axis. The rotation shaft 106 extends in the rotation axis direction of the rotary device body 90. The support member 100 is a support member that supports the magnet 101. In other words, the magnet 101 supported by the support member 100 can also rotate with the rotation shaft 106 as a rotation axis. Specifically, the rotation axis of the magnet 101 extends in the rotation axis direction of the rotary device body 90.

[0227] The magnet unit 103 can be seen as being disposed inside the developing frame 53 to be movable (rotatable) with respect to the developing frame 53. More specifically, the magnet unit 103 can rotate with respect to the developing frame 53 (housing portion) via the rotation shaft 106 (to-be-supported unit). In other words, the magnet unit 103 rotates with respect to the developing frame 53 about the rotation shaft extending in the rotation axis direction of the rotary device body 90.

[0228] The magnet 101 is a magnet. The density of the support member 100 is lower than the density of the magnet 101. In view of the application of the present embodiment, the magnet 101 does not necessarily need to be a magnet, and any member can be used as long as it is a magnet that generates a magnetic field. The shape and size of the magnet 101 are desirably modified as appropriate in accordance with the desired characteristics of the magnet 101.

[0229] As shown in FIG. 14A and FIG. 14B The magnet 101 includes a to-be-supported surface (magnet first surface) 101s1 in contact with the support member 100. The magnet 101 also includes a magnet second surface 101s2 positioned opposite the to-be-supported surface 101s1. The support member 100 includes a first surface 100s1 in contact with the to-be-supported surface 101s1 and a second surface 100s2 as a surface positioned opposite the first surface 100s1. The to-be-supported surface 101s1, the first surface 100s1, and the second surface 100s2 each extend in the direction of the rotation axis 90C (Y direction) of the rotary device body 90.

[0230] The lengths of the first surface 100s1 and the second surface 100s2 in the direction of the rotation axis 90C of the rotary device body 90 are both greater than the length of the to-be-supported surface 101s1 in the direction of the rotation axis 90C of the rotary device body 90. The areas of the first surface 100s1 and the second surface 100s2 are both greater than the area of the to-be-supported surface 101s1. This makes it less likely that the magnet unit 103 will be buried in toner during the detection of the remaining toner level to be described below, and enables accurate detection of the toner remaining level.

[0231] In the following description, the axis of rotation of magnet unit 103 will be referred to as the axis of rotation A1. The radial direction about the axis of rotation A1 and from the center of rotation of magnet unit 103 toward magnet 101 will be referred to as the outward radial direction. The downstream end of magnet unit 103 in the outward radial direction will be referred to as the bottom end 103d of magnet unit. The center of gravity of magnet unit 103 will be referred to as the center of gravity Zm.

[0232] The distance between the rotation axis A1 in the outward radial direction and the center of gravity Zm of the magnet unit 103 will be referred to as distance D1. The distance between the center of gravity Zm of the magnet unit 103 in the outward radial direction and the bottom end 103d of the magnet unit will be referred to as distance D2. Distance D1 is greater than distance D2. This promotes the rotation of the magnet unit 103 compared to the case where distance D1 is less than distance D2. Therefore, even if toner accumulates near the rotation axis 106 and interferes with the rotation of the magnet unit 103, the magnet unit 103 can easily rotate.

[0233] Next, we will refer to FIGS. 15-19A to FIG. 19C This describes a method for determining the amount of toner in the developing container 53a. First, refer to... FIG. 15 The configuration of the control unit of the image forming apparatus 1 is described. FIG. 15 This is a block diagram showing the configuration of the control unit of the image forming apparatus 1.

[0234] The image forming apparatus 1 includes an engine control unit 500, a controller 600, and a display unit 700. A host computer 400 transmits print jobs to the image forming apparatus 1. Upon receiving the print jobs from the host computer 400, the controller 600 causes the engine control unit 500 to control the image forming operation based on the print jobs. The display unit 700 is a display device capable of displaying information. An example of the display unit 700 is a display device with a display screen, such as a monitor. FIGS. 6A-6C As shown, the display unit 700 is deployed on the frame 16.

[0235] The engine control unit 500 includes a central processing unit (CPU) 510, a read-only memory (ROM) 520, and a random access memory (RAM) 530. The ROM 520 is a non-volatile memory that holds and stores control programs and various types of data. The ROM 520 stores the determination results of the amount of toner in the developing frame 53 by the CPU 510, which will be described below. The RAM 530 is a volatile memory that stores temporary data.

[0236] The magnetic sensor 102 detects the magnetic field generated by the magnet 101 and outputs a signal based on the magnetic field generated by the magnet 101 to the CPU 510 of the engine control unit 500. The CPU 510 of the engine control unit 500 performs a first determination of determining the amount of toner accommodated in the developing frame 53 based on the signal output from the magnetic sensor 102. In other words, the engine control unit 500 can be referred to as a first determination unit that performs the first determination.

[0237] The engine control unit 500 controls the controller 600 to notify the display unit 700 of first information about the determination result of the first determination. The controller 600 can be referred to as a notification unit. The display unit 700 displays the first information notified by the controller 600. The first information is information about the result of the first determination. For example, the first information is information about the amount of toner. For example, the first information is information suggesting replacement of the toner cartridge 70. In other words, the engine control unit 500 can output a signal related to the amount of toner accommodated in the developing frame 53 based on the signal (sensor output signal) output from the magnetic sensor 102.

[0238] The engine control unit 500 also performs a second determination of determining the amount of toner accommodated in the toner cartridge 70 based on the determination result of the first determination. In other words, the engine control unit 500 can be referred to as a second determination unit that performs the second determination.

[0239] The engine control unit 500 controls the controller 600 to notify the display unit 700 of second information about the determination result of the second determination. The display unit 700 displays the second information notified by the controller 600. The second information is information about the result of the second determination. For example, the second information is information about the amount of toner. For example, the second information is information suggesting replacement of the toner cartridge 70. In other words, the engine control unit 500 can output a signal related to the amount of toner accommodated in the toner cartridge 70 based on the signal (sensor output signal) output from the magnetic sensor 102.

[0240] Next, a method for detecting a decrease in the amount of toner in the developing frame 53 will be described with reference to FIGS. 16-18 The method for detecting a decrease in the amount of toner in the developing frame 53k will be described as an example in the following description. However, the description also applies to the case of detecting the amount of toner in the developing frames 53y, 53m, and 53c.

[0241] FIG. 16 is a cross-sectional view of the rotary device main body 90, illustrating a state in which the developing frame 53 accommodates 100% toner. FIG. 17 is a cross-sectional view of the rotary device main body 90, illustrating a state in which the developing frame 53 accommodates 80% toner. FIG. 18is a cross-sectional view of the rotary device main body 90, illustrating a state in which the developing frame 53 accommodates 60% toner.

[0242] As described above, the magnet unit 103k can move with respect to the developing frame 53k.

[0243] As FIG. 16 indicated in FIG. 6, when there is sufficient toner in the developing frame 53k, the magnet unit 103k is positioned near the accommodation portion downstream end 53rdk. At least a portion of the magnet unit 103k desirably contacts the accommodation portion downstream end 53rdk.

[0244] In a state in which image formation is performed from FIG. 16 , the amount of toner accommodated in the developing frame 53 decreases. When the amount of toner in the developing frame 53k decreases to FIG. 17 , the magnet unit 103k moves downward with respect to the accommodation portion downstream end 53rdk compared to the state of FIG. 16 . When the toner in the developing frame 53 is further consumed from the state of FIG. 17 to the state of FIG. 18 , the magnet unit 103k moves further downward with respect to the accommodation portion downstream end 53rd compared to the state of FIG. 17 .

[0245] FIGS. 19A-19C are output waveforms of signals output by the magnetic sensor 102 when detecting the magnetic field generated by the magnet 101 in the state of FIGS. 16-18 . FIG. 19A is an output waveform in a state in which the remaining toner level is FIG. 16 . FIG. 19B is an output waveform in a state in which the remaining toner level is FIG. 17 . FIG. 19C is an output waveform in a state in which the remaining toner level is FIG. 18 . The vertical axis indicates an output amount based on the magnetic flux detected by the magnetic sensor 102. The horizontal axis indicates elapsed time from the start of rotation (revolution) of the rotary device main body 90.

[0246] As described above, as the amount of toner accommodated in the developing frame 53k decreases, the magnet unit 103k moves downward with respect to the developing frame 53k and the distance between the magnet unit 103k and the developing frame 53k increases. In other words, the distance between the magnetic sensor 102 and the magnet unit 103k increases. The direction of the magnet 101 also changes so that the magnetic field detectable by the magnetic sensor 102 decreases. More specifically, as the amount of toner accommodated in the developing frame 53k decreases, the direction of the magnet 101 changes so that the angle formed between the direction orthogonal to the magnet second surface 101s2 and the direction from the magnetic sensor 102 to the rotary device center Rm increases. As the amount of toner accommodated in the developing frame 53k decreases, the magnetic field of the magnet 101 detected by the magnetic sensor 102 thus decreases. Therefore, as the amount of toner accommodated in the developing frame 53k decreases, the output value of the output waveform decreases. The engine control unit 500 determines that the amount of toner is decreasing based on the decrease in the output value of the output waveform.

[0247] In the present embodiment, the aspect ratio of the magnet, the distance between the magnetic sensor 102 and the magnet 101, and the sensitivity of the magnetic sensor 102 are designed so that the output value of the magnetic sensor 102 falls within the range of 100% to 0% when the amount of toner in the developing frame 53 is within the range of 100% to 60%.

[0248] The configuration can be designed so that the output value sharply decreases when the amount of toner in the developing frame 53 decreases from the vicinity of the toner level at which it is determined that the toner cartridge 70 is expected to be replaced. For example, assume that the toner level at which it is determined that the toner cartridge is expected to be replaced is set to 80%. In this case, the amount of decrease in the output value can increase when the remaining toner level decreases from 85% to 75%. For example, the amount of decrease in the output value when the remaining toner level decreases from 85% to 75% is greater than the amount of decrease in the output value when the remaining toner level decreases from 100% to 90%.

[0249] Since the output sharply changes around the threshold value, the configuration for causing the sensor output to sharply decrease can improve the detection accuracy around the threshold value.

[0250] Next, the operation of the magnet unit 103 associated with the rotation of the rotary device body 90 will be described with reference to FIGS. 20A-20D The operation of the magnet unit 103 associated with the rotation of the rotary device body 90 will be described with reference to FIGS. 20A-20D The various orientations assumed by the rotary device body 90 during the period in which one rotation is performed (hereinafter referred to as the rotation period) are illustrated. Just as FIG. 17 As described above, as the amount of toner accommodated in the developing frame 53k decreases, the magnet unit 103k moves downward with respect to the developing frame 53k and the distance between the magnet unit 103k and the developing frame 53k increases. In other words, the distance between the magnetic sensor 102 and the magnet unit 103k increases. The direction of the magnet 101 also changes so that the magnetic field detectable by the magnetic sensor 102 decreases. More specifically, as the amount of toner accommodated in the developing frame 53k decreases, the direction of the magnet 101 changes so that the angle formed between the direction orthogonal to the magnet second surface 101s2 and the direction from the magnetic sensor 102 to the rotary device center Rm increases. As the amount of toner accommodated in the developing frame 53k decreases, the magnetic field of the magnet 101 detected by the magnetic sensor 102 thus decreases. Therefore, as the amount of toner accommodated in the developing frame 53k decreases, the output value of the output waveform decreases. The engine control unit 500 determines that the amount of toner is decreasing based on the decrease in the output value of the output waveform. FIGS. 20A-20DThe state in which the amount of toner in the developing frame 53 is 80% is illustrated. The rotary device body 90 is rotated once in the Rl direction in the order of FIG. 20A , FIG. 20B , FIG. 20C , FIG. 20D and FIG. 20A .

[0251] In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53k will be referred to as the first orientation. FIG. 20A FIG. 20B In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53k will be referred to as the first orientation. FIG. 20C FIG. 20D In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53k will be referred to as the first orientation.

[0252] In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53y will be referred to as the first orientation. FIG. 20B FIG. 20C In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53y will be referred to as the first orientation. FIG. 20D FIG. 20A In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53y will be referred to as the first orientation.

[0253] In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53m will be referred to as the first orientation. FIG. 20C FIG. 20D In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53m will be referred to as the first orientation. FIG. 20A FIG. 20B In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53m will be referred to as the first orientation.

[0254] In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53c will be referred to as the first orientation. FIG. 20D FIG. 20A In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53c will be referred to as the first orientation. FIG. 20B FIG. 20C In the following description, the orientation of the rotary device body 90 in the detection of the amount of toner in the developing frame 53c will be referred to as the first orientation.

[0255] ​​​​​​​​First, the movement of the magnet unit 103k when the rotary device body 90 is transitioned from the first orientation to the second orientation will be described. When the rotary device body 90 assumes the first orientation, the magnet unit 103k is located above the rotary device center Rm. In the following description, a straight line passing through the rotary device center Rm and the magnetic sensor 102 when viewed in the rotary axis direction of the rotary device body 90 will be referred to as straight line L1.

[0256] When the rotary device body 90 is in the first orientation, the magnet unit 103k intersects the straight line L1 when viewed in the rotary axis direction of the rotary device body 90. In other words, the center of rotation of the rotary device body 90, the magnet unit 103k (magnet 101k), and the magnetic sensor 102 are aligned on a straight line in the radial direction of the rotation of the rotary device body 90 (first radial direction) when viewed in the rotary axis direction of the rotary device. In the following description, the timing when the center of rotation of the rotary device body 90, the magnet unit 103k (magnet 101k), and the magnetic sensor 102 are aligned on a straight line in the first radial direction will be referred to as the collocation timing.

[0257] At the collocation timing of the developing frame 53k, the magnet unit 103k (magnet 101k) is closer to the magnetic sensor 102 than the center of rotation of the rotary device body 90 in the radial direction of the rotation of the rotary device body 90. The magnet unit 103k (magnet 101k) is located between the center of rotation of the rotary device body 90 and the magnetic sensor 102 in the radial direction of the rotation of the rotary device body 90.

[0258] When the rotary device body 90 is rotated in the R1 direction and is transitioned from the first orientation to the second orientation, the magnet unit 103k also revolves in the R1 direction with the rotary device center Rm as the center of rotation and moves downward. The magnet unit 103k also moves downstream in the retraction direction of the toner cartridge 70. While revolving in the R1 direction, the magnet unit 103k also rotates in the R2 direction with the rotary axis 106 as the rotary axis. The R2 direction is opposite to the R1 direction. The transition period from the first orientation to the second orientation will be referred to as the second period. In the second period, the magnet unit 103 can be seen as being allowed to move in a direction from the upstream end 53ruk of the accommodation portion toward the downstream end 53rdk of the accommodation portion. The rotation period can be seen as including the second period.

[0259] When the rotary device body 90 is rotated in the Rl direction and changes from the first orientation to the second orientation, the toner also moves in the direction from the upstream end 53ruk of the containing portion to the downstream end 53rdk of the containing portion. When the magnet unit 103k is rotated in the R2 direction, the magnet unit 103k approaches the downstream end 54rdk of the containing portion and eventually comes into contact with the downstream end 53rdk of the containing portion. In the case where the magnet unit 103k is in contact with the downstream end 53rdk of the containing portion, it is less likely that toner enters the space between the magnet unit 103k and the downstream end 53rdk of the containing portion. This makes it possible to achieve accurate detection of the amount of toner in the developing frame 53 in the first period, which will be described later.

[0260] When the rotary device body 90 assumes the second orientation, the magnet unit 103k is located downstream of the rotary device center Rm in the retracting direction of the toner cartridge 70. Also, when the rotary device body 90 assumes the second orientation, at least a portion of the magnet unit 103k and the rotary device center Rm overlap in the vertical position.

[0261] Next, the mechanism when the rotary device body 90 changes from the second orientation to the third orientation will be described. When the rotary device body 90 is rotated in the Rl direction and changes from the second orientation to the third orientation, the magnet unit 103k also revolves to move downward. The magnet unit 103k also moves upstream in the retracting direction of the toner cartridge 70. When the magnet unit 103k revolves in the Rl direction, the magnet unit 103k is subjected to gravity, which urges the magnet unit 103k to move toward the downstream end 53rdk of the containing portion. Since the magnet unit 103k is in contact with the downstream end 53rd of the containing portion, rotation about the rotation axis 106 is restricted. When the rotary device body 90 assumes the third orientation, the magnet unit 103k is located below the rotary device center Rm. When the rotary device body 90 assumes the third orientation, at least a portion of the magnet 101 and the rotary device center Rm are located at the same position in the retracting direction of the toner cartridge 70.

[0262] Next, the mechanism when the rotary device body 90 is transitioned from the third orientation to the fourth orientation will be described. When the rotary device body 90 is rotated in the Rl direction and is transitioned from the third orientation to the fourth orientation, the magnet unit 103k revolves in the Rl direction to move upward. The magnet unit 103k also moves upstream in the retraction direction of the toner cartridge 70. Here, the magnet unit 103k is subjected to gravity and rotates in the Rl direction about the rotation axis 106. More specifically, the magnet unit 103k rotates in a direction from the accommodation portion downstream end 53rdk to the accommodation portion upstream end 53ruk. The period when the rotary device body 90 is transitioned from the third orientation to the fourth orientation can be regarded as a first period during which a direction in which the magnet unit 103 is allowed to move relative to the developing frame 53 includes a gravity direction component. In the first period, the moving direction in which the magnet unit 103 can move relative to the developing frame 53 can also be regarded as including a vertically downward component. A rotation period in which the rotary device body 90 performs one rotation can be regarded as including the first period.

[0263] More specifically, the direction in which the magnet unit 103 is allowed to move is a direction from the accommodation portion downstream end 53rdk toward the accommodation portion upstream end 53ruk. In other words, in the first period, the moving direction in which the magnet unit 103 can move relative to the developing frame 53 is a direction from the accommodation portion downstream end 53rdk toward the accommodation portion upstream end 53ruk. In the first period, the rotating direction of the magnet unit 103 is the same as the rotating direction of the rotary device body 90.

[0264] The first period includes an interference period during which the magnet unit 103k is in contact with the toner, thereby preventing (interfering with) movement of the magnet unit 103k in a direction including a gravity direction component.

[0265] In other words, the first period can be regarded as including a contact period during which the magnet unit 103 is in contact with and received by the toner (developer). More specifically, in the contact period, the second surface 100s2 is in contact with and received by the developer.

[0266] When the rotary device body 90 assumes the fourth orientation, the magnet 101k is located upstream of the rotary device center Rm in the retraction direction of the toner cartridge 70. Also, when the rotary device body 90 assumes the fourth orientation, the rotary device center Rm overlaps at least a portion of the magnet 101k in a vertical position.

[0267] Next, the mechanism when the rotary device body 90 is transitioned from the fourth orientation to the first orientation will be described. When the rotary device body 90 is rotated in the R1 direction and is transitioned from the fourth orientation to the first orientation, the magnet unit 103 revolves in the R1 direction to move upward. The magnet unit 103k also moves downstream in the retraction direction of the toner cartridge 70. Here, the magnet unit 103k rotates in the R1 direction. More specifically, the magnet unit 103k rotates in a direction from the accommodation portion downstream end 53rdk to the accommodation portion upstream end 53ruk. That is, the period when the rotary device body 90 is transitioned from the fourth orientation to the first orientation can be regarded as a first period during which a direction in which the magnet unit 103 is allowed to move relative to the developing frame 53 includes a gravitational direction component.

[0268] In other words, in the first period, a direction in which the magnet unit 103 can move relative to the developing frame 53 can be regarded as including a vertically downward component. A rotation period in which the rotary device body 90 is rotated once can be regarded as including the first period.

[0269] More specifically, the direction in which the magnet unit 103 is allowed to move is a direction from the accommodation portion downstream end 53rdk toward the accommodation portion upstream end 53ruk. That is, in the first period, a direction in which the magnet unit 103 can move relative to the developing frame 53 is a direction from the accommodation portion downstream end 53rdk toward the accommodation portion upstream end 53ruk.

[0270] The first period includes an interference period during which the magnet unit 103k is in contact with the toner, thereby preventing (interfering with) movement of the magnet unit 103k in a direction including a gravitational direction component. In other words, the first period can be regarded as including a contact period during which the magnet unit 103 is in contact with the toner (developer) and is received by the developer. In the contact period, the second surface 100s2 is in contact with and is received by the developer. The first period includes a side-by-side timing.

[0271] More specifically, the contact period includes the side-by-side timing.

[0272] As shown in FIG. 10, among the radial directions of the rotation of the rotary device body 90, a direction from the rotation center Rm to the magnetic sensor 102 will be referred to as a sensor radial direction. FIG. 20A The amount of developer accommodated in the developing frame 53 in the state of FIG. 10 will be referred to as a first amount. FIG. 16 The amount of developer accommodated in the developing frame 53 in the state of FIG. 11 will be referred to as a second amount. FIG. 17 The amount of developer accommodated in the developing frame 53 in the state of FIG. 11 will be referred to as a second amount.

[0273] When the amount of the developer accommodated in the developing frame 53 is the first amount, the distance between the magnetic sensor 102 in the sensor radial direction and the magnet 101k at the time of the side-by-side can be considered a first distance. When the amount of the developer accommodated in the developing frame 53 is a second amount smaller than the first amount, the distance between the magnetic sensor 102 in the sensor radial direction and the magnet 101k at the time of the side-by-side can be considered a second distance. The second distance is greater than the first distance.

[0274] At the time of the side-by-side, the distance between the rotation shaft 106 (to-be-supported unit) in the sensor radial direction and the accommodation portion downstream end 53rd is smaller than the distance between the rotation shaft 106 (to-be-supported unit) in the sensor radial direction and the accommodation portion upstream end 53ru. This makes it less likely that the magnet unit 103 is buried in the toner at the time of the side-by-side.

[0275] The magnetic sensor 102 according to the present embodiment detects the magnetic field of the magnet 101 when the rotary device main body 90 performs one rotation, and outputs a signal. More specifically, the magnetic sensor 102 outputs a signal based on the magnetic field generated by the magnet 101 in at least a portion of the first period. In the present embodiment, the magnetic sensor 102 continues to detect during the rotation period of one rotation of the rotary device main body 90. However, the magnetic sensor 102 can perform detection only for a period shorter than the period of one rotation of the rotary device main body 90. In this case, the magnetic sensor 102 desirably detects the magnetic field in at least a portion of the period in which the rotary device main body 90 transitions from the third orientation to the first orientation.

[0276] As described above, the rotation of the rotary device main body 90 can move the magnet 101 relative to the developer. This makes it possible to achieve a reduction in the moving members for moving the magnet relative to the developer.

[0277] While the present application has been described with reference to exemplary embodiments, it is to be understood that the application is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An image forming apparatus comprising: a developing unit including (I) an accommodating portion configured to accommodate a developer, (II) a developing member configured to develop an electrostatic latent image formed on a photosensitive drum with the developer accommodated in the accommodating portion, and (III) a magnet unit including a magnet, the magnet unit being located inside the accommodating portion and supported so as to be movable in a moving direction with respect to the accommodating portion; a rotating device configured to rotate, the rotating device including the developing unit; and a magnetic sensor, wherein a rotation period in which the rotating device performs one rotation includes a first period, wherein in the first period, the moving direction includes a vertically downward component, wherein the first period includes a contact period during which the magnet unit contacts and is received by the developer, wherein the contact period includes a collocation timing at which, when viewed in a rotation axis direction of the rotating device, a rotation center of the rotating device, the magnet unit, and the magnetic sensor are aligned on a straight line in a radial direction of rotation of the rotating device, and wherein the magnetic sensor is configured to output a signal based on a magnetic field generated by the magnet in at least a portion of the first period.

2. The image forming apparatus according to claim 1, wherein a direction from the rotation center of the rotating device to the magnetic sensor among the radial direction of rotation of the rotating device is a sensor radial direction, wherein a first distance is a distance between the magnetic sensor and the magnet in the sensor radial direction at the collocation timing in a case where an amount of the developer accommodated in the accommodating portion is a first amount, wherein a second distance is a distance between the magnetic sensor and the magnet in the sensor radial direction at the collocation timing in a case where an amount of the developer accommodated in the accommodating portion is a second amount, the second amount being smaller than the first amount, and wherein the second distance is greater than the first distance.

3. The image forming apparatus according to claim 1, wherein the magnetic sensor is located above the rotation center of the rotating device when the image forming apparatus is installed on a horizontal plane.

4. The image forming apparatus according to claim 3, wherein a rotating device end portion is an uppermost end of the rotating device, and wherein the magnetic sensor is located above the rotating device end portion.

5. The image forming apparatus according to claim 2, wherein the magnet unit includes a to-be-supported unit supported by the accommodating portion, wherein a downstream end of the accommodating portion in the sensor radial direction is an accommodating portion downstream end, wherein an upstream end of the accommodating portion in the sensor radial direction is an accommodating portion upstream end, and wherein a distance between the to-be-supported unit and the accommodating portion downstream end in the sensor radial direction at the collocation timing is smaller than a distance between the to-be-supported unit and the accommodating portion upstream end in the sensor radial direction at the collocation timing. ​ 6.The image forming apparatus according to claim 5, wherein the magnet unit is configured to rotate relative to the housing portion via the support-to-be-supported unit. 7.The image forming apparatus according to claim 6, wherein the magnet unit is configured to rotate relative to the housing portion about a rotation axis extending in a direction along a rotation axis of the rotary device. 8.The image forming apparatus according to claim 7, wherein in the first period, a rotation direction of the magnet unit is the same as a rotation direction of the rotary device. 9.The image forming apparatus according to claim 5, wherein in the side-by-side timing, the moving direction is a direction approaching an upstream end of the housing portion from a downstream end of the housing portion. 10.The image forming apparatus according to claim 5, wherein the rotation period includes a second period during which the magnet unit is configured to move in a direction approaching a downstream end of the housing portion from an upstream end of the housing portion. 11.The image forming apparatus according to claim 1, wherein the magnet unit includes a support member having a density lower than a density of the magnet, the support member being a support unit configured to support the magnet. 12.The image forming apparatus according to claim 11, wherein the magnet includes a surface to be supported, wherein the support member includes a first surface in contact with the surface to be supported and a second surface opposite to the first surface, and wherein the second surface is configured to contact and be received by a developer in the contact period. 13.The image forming apparatus according to claim 12, wherein the second surface has an area larger than an area of the surface to be supported. 14.The image forming apparatus according to claim 1, further comprising: a first determination unit configured to perform a first determination of an amount of developer accommodated in the housing portion based on a signal output from the magnetic sensor, and a control unit configured to control a notification unit configured to notify first information about a determination result of the first determination unit. 15.The image forming apparatus according to claim 14, wherein the image forming apparatus is configured such that a cartridge configured to accommodate a developer is detachably attached thereto, and wherein a developer is supplied from the cartridge to the housing portion. 16.The image forming apparatus according to claim 15, further comprising a second determination unit configured to perform a second determination of an amount of developer accommodated in the cartridge based on a determination result of the first determination, wherein the control unit is configured to control the notification unit such that the notification unit is configured to notify second information about a determination result of the second determination unit. 17.The image forming apparatus according to claim 16, further comprising a display unit configured to display the first information or the second information notified by the notification unit. 18.The image forming apparatus of claim 1, wherein the magnet is a magnet. 19.The image forming apparatus of claim 1, further comprising a tray configured to hold a cartridge in a detachably attached manner, the cartridge being configured to accommodate a developer, wherein the tray is configured to move to an accommodation position in which the cartridge is located inside the rotating device and a detachment position in which the cartridge is located outside the rotating device.

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