Image forming apparatus

Abstract

To allow a user to easily recognize the necessity of replacement of a cartridge in an image forming apparatus.SOLUTION: A replacement control section (engine control section), when receiving an instruction to move a cartridge, performs moving processing of controlling a moving device to move the cartridge from a mounted position to a retreat position. When a result of acquisition of the amount of toner remaining in the cartridge satisfies a predetermined condition, the replacement control section performs the processing of moving the cartridge even when not receiving the instruction to move the cartridge.SELECTED DRAWING: Figure 16

Description

[Technical Field]

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

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

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-183305 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-096852 Summary of the Invention [Problem to be solved by the invention]

[0004] In an image forming apparatus using the rotary development system described above, for example, when the amount of toner remaining in the toner cartridge becomes low, image formation may become impossible. In such a case, the image forming apparatus must prompt the user to replace the toner cartridge, for example by displaying a message on a display unit. However, if the user does not notice such a message, after inputting an image formation instruction to the image forming apparatus, the image formation operation will not be performed, and the user will only realize the need to replace the toner cartridge. As a result, it will take some time for the toner cartridge replacement work to be completed and image formation to become possible.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a technique that makes it easier for a user to recognize the need for cartridge replacement in an image forming apparatus. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided an image forming device in which a cartridge containing toner can be attached and detached, the image forming device comprising: a photosensitive member; a developing unit that develops an electrostatic latent image formed on the photosensitive member with the toner supplied from the cartridge; a rotatable rotary; a moving device that moves the cartridge to an attached position where the cartridge is located inside the rotary; and a retracted position where the cartridge is located outside the rotary; a control means that performs a moving process to control the moving device to move the cartridge from the attached position to the retracted position when a moving instruction for the cartridge is received; and an acquisition unit that acquires the amount of toner remaining in the cartridge, wherein the control means performs the moving process when the acquisition result from the acquisition unit satisfies a predetermined condition, even if the moving instruction has not been received. [Effects of the Invention]

[0007] According to the present invention, the user can easily recognize the need to replace the cartridge in the image forming apparatus. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Figure 2] FIG. 2 is a schematic diagram illustrating the driving configuration of the image forming apparatus. [Figure 3] Schematic diagram of a developing unit, a cartridge, and a tray. [Figure 4] FIG. 2 is a cross-sectional view of the rotary and its vicinity in the image forming apparatus. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a cross-sectional view of the rotary and its vicinity in the image forming apparatus. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. 4 is an explanatory diagram of a tray movement configuration. [Figure 12] FIG. 4 is an explanatory diagram of a tray movement configuration. [Figure 13] FIG. 10 is a diagram showing an example of detection of the tray state. [Figure 14] FIG. 10 is a diagram showing an example of detection of the tray state. [Figure 15] FIG. 2 is a block diagram showing an example of the control configuration of the image forming apparatus and an example of the functional configuration of an engine control unit. [Figure 16] 10 is a flowchart showing an example of a procedure for controlling the movement of a cartridge. [Figure 17] 10 is a flowchart showing an example of a procedure for controlling the movement of a cartridge. [Figure 18] 10 is a flowchart showing an example of a procedure for sleep transition control and sleep return control. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

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

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

[0012] The schematic configuration and image forming operation of image forming apparatus 1 will be described using Figures 1, 2, and 3. Figure 1 is a schematic diagram showing the cross-sectional configuration of image forming apparatus 1. Figure 2 is a diagram explaining the drive source of image forming apparatus 1. Figure 3 is a conceptual diagram showing the configuration for replenishing toner from toner cartridge 70 to developing unit 50. Note that in this specification, toner cartridge is also simply referred to as "cartridge." As shown in Figure 1, image forming apparatus 1 has image forming apparatus main body (hereinafter referred to as apparatus main body) 1A and cartridges 70y, 70m, 70c, and 70k that are detachable from apparatus main body 1A. Apparatus main body 1A is the portion of image forming apparatus 1 excluding cartridges 70y, 70m, 70c, and 70k.

[0013] The apparatus main body 1A has a drum-shaped (cylindrical) electrophotographic photosensitive member (hereinafter referred to as photosensitive drum) 2 as an image carrier that carries an electrostatic latent image. A charging roller 3, a scanner 4 as an exposure device, and a cleaning unit 6 are arranged around the photosensitive drum 2. The charging roller 3 is an example of a charging unit that uniformly charges the photosensitive drum 2. The scanner 4 is an example of an exposure unit that irradiates the photosensitive drum 2 with laser light according to image information to expose it. An electrostatic latent image is formed on the photosensitive drum 2 by irradiating the charged photosensitive drum 2 with laser light. The cleaning unit 6 is an example of a cleaning member that removes toner remaining on the surface of the photosensitive drum 2.

[0014] Furthermore, the apparatus main body 1A has a sheet storage section 300, a pickup roller 310, a feed roller 311, a separation roller 312, a pair of conveying rollers 320, a secondary transfer roller 12, a fixing device 40, and an intermediate transfer unit 10. The pickup roller 310 is an example of a feeding section that feeds the sheet S. The feed roller 311 and the separation roller 312 are examples of a separation conveying unit that separates and conveys the sheets S one by one by frictional force. The secondary transfer roller 12 is an example of a transfer unit that transfers an image from the intermediate transfer belt 10a to the sheet S.

[0015] The intermediate transfer unit 10 has an intermediate transfer belt 10a, a belt drive roller 10b, a tension roller 10c, a cleaning device 13, and a primary transfer roller 11. The intermediate transfer belt 10a is an example of an intermediate transfer body that carries an image transferred (primary transfer) from the photosensitive drum 2 and transports it for transfer (secondary transfer) onto a sheet S. The intermediate transfer belt 10a is stretched over the belt drive roller 10b and the tension roller 10c. The belt drive roller 10b is rotationally driven by a drive source, thereby rotating the intermediate transfer belt 10a.

[0016] The apparatus main body 1A also has a rotary main body (rotary, rotating body) 90 having developing units 50y, 50m, 50c, and 50k. As will be described later, in this embodiment, trays 80y, 80m, 80c, and 80k are attached to the rotary main body 90. Cartridges 70y, 70m, 70c, and 70k are removably attached to the trays 80y, 80m, 80c, and 80k.

[0017] The tray 80k supports the cartridge 70k. The tray 80m supports the cartridge 70m. The tray 80y supports the cartridge 70y. The tray 80c supports the cartridge 70c.

[0018] The developing units 50y, 50m, 50c, and 50k develop (visualize) the electrostatic latent images formed on the photosensitive drum 2 into toner images using toner of the corresponding color. The developing units 50y, 50m, 50c, and 50k develop the electrostatic latent images formed on the photosensitive drum 2 using yellow toner, magenta toner, cyan toner, and black toner, respectively.

[0019] The developing unit 50y has a developing roller 51y, a supply roller 52y, and a developing blade. The developing roller 51y is a developer carrier that carries toner as a developer and rotates to supply the toner to the photosensitive drum 2. The supply roller 52y is disposed in contact with the developing roller 51y and is a supply member that supplies toner to the developing roller 51y. The developing blade is a regulating member that regulates the thickness of the toner layer carried by the developing roller 51y. The other developing units 50m, 50c, and 50k also have similar developing rollers 51m, 51c, and 51k, supply rollers 52m, 52c, and 52k, and developing blades.

[0020] Cartridges 70y, 70m, 70c, and 70k corresponding to the developing units 50y, 50m, 50c, and 50k are attached adjacent to the developing units 50y, 50m, 50c, and 50k, respectively, to the rotary body 90. The cartridges 70y, 70m, 70c, and 70k contain yellow toner, magenta toner, cyan toner, and black toner, respectively, to be supplied to the developing units 50y, 50m, 50c, and 50k.

[0021] The rotary main body 90 has a rotary frame 90f that supports the developing units 50y, 50m, 50c, and 50k. The developing units 50y, 50m, 50c, and 50k are supported by the rotary frame 90f, which is a rotatable support body.

[0022] Trays 80y, 80m, 80c, and 80k are attached to the rotary body 90. The combination of the rotary body 90 and the trays 80y, 80m, 80c, and 80k can be called the rotary unit 90U. In other words, the rotary unit 90U has the rotary body 90 and the trays 80y, 80m, 80c, and 80k.

[0023] The cartridges 70y-70k are detachably held in the trays 80y-80k. As will be described later, the trays 80y-80k are supported so as to be slidable to the outside of the rotary main body 90. The combination of the rotary unit 90U and the cartridges 70y, 70m, 70c, and 70k can be referred to as the rotary assembly 90A. In other words, the rotary assembly 90A has the rotary unit 90U and the cartridges 70y, 70m, 70c, and 70k.

[0024] As will be described later, the rotary body 90 is rotatable around a rotation axis (rotation center) 90C. The rotation axis 90C coincides with the rotation axes of the rotary frame 90f, the rotary unit 90U, and the rotary assembly 90A. The rotation axis 90C is also substantially parallel to the rotation axis (rotation center) of the photosensitive drum 2.

[0025] The rotary body 90 can rotate about the rotation axis 90C to assume a developing position in which any one of the developing rollers 51y, 51m, 51c, and 51k faces the photosensitive drum 2. The position in which the developing roller 51y faces the photosensitive drum 2 is called the yellow developing position. The position in which the developing roller 51m faces the photosensitive drum 2 is called the magenta developing position. The position in which the developing roller 51c faces the photosensitive drum 2 is called the cyan developing position. The position in which the developing roller 51k faces the photosensitive drum 2 is called the black developing position. In other words, the rotary body 90 can rotate about the rotation axis 90C so that the positions of the developing rollers 51y, 51m, 51c, and 51k relative to the photosensitive drum 2 can change.

[0026] 2, the device main body 1A has motors M1, M2, and M3 as drive sources. As will be described later, the motor M1 supplies a drive force for rotating the rotary main body 90 about the rotation axis 90C. In other words, the motor M1 rotates the rotary assembly 90A and the rotary unit 90U about the rotation axis 90C.

[0027] The apparatus main body 1A also has a drive device 98 including a motor M2 and a transmission device. The transmission device includes drive racks 15L, 15R as drive gears, and a transmission unit 15t, which will be described later. The driving force of the motor M2 is transmitted to the drive racks 15L, 15R by the transmission unit 15t. In other words, the motor M2 is configured to drive the drive racks 15L, 15R, and moves the trays 80y, 80m, 80c, and 80k relative to the rotary main body 90 via the drive racks 15L, 15R.

[0028] Motor M3 drives components other than those driven by motors M1 and M2, such as the photosensitive drum 2, developing units 50y, 50m, 50c, and 50k, pickup roller 310, feed roller 311, conveying roller pair 320, secondary transfer roller 12, belt drive roller 10b, and fixing device 40.

[0029] The components driven by motors M1, M2, and M3 can be changed as needed. Also, the functions of any two or all three of motors M1, M2, and M3 can be combined into one motor. Alternatively, drive sources other than motors M1, M2, and M3 may be added.

[0030] Here, the subscripts y, m, c, and k attached to the developing units 50y, 50m, 50c, and 50k, the cartridges 70y, 70m, 70c, and 70k, and the trays 80y, 80m, 80c, and 80k indicate the toner colors. The developing units 50y, 50m, 50c, and 50k have the same basic configuration and function. The cartridges 70y, 70m, 70c, and 70k have the same basic configuration and function. The trays 80y, 80m, 80c, and 80k also have the same basic configuration and function. Therefore, when it is not necessary to distinguish between them, the subscripts y, m, c, and k are omitted, and the description will be given assuming that the unit is any one of the four units, cartridges, and trays.

[0031] 3, the cartridge 70 has a toner frame 71. The toner frame 71 has a toner storage section 71a that stores toner, and a discharge opening 71b that communicates with the toner storage section 71a.

[0032] The developing unit 50 has a developing frame (storage frame) 53. The developing frame 53 has a developing-side storage portion 53a and a receiving opening 53b that communicates with the developing-side storage portion (toner supply chamber) 53a. As mentioned above, the developing unit 50 has the developing roller 51, the supply roller 52, etc., but these members are omitted in Figure 3.

[0033] As will be described later, the cartridge 70 is movable relative to the developing frame 53 between an attached position and a retracted position retracted from the attached position. When the cartridge 70 is in the attached position relative to the developing frame 53, the discharge opening 71b faces the receiving opening 53b. In other words, the toner storage portion 71a of the cartridge 70 and the developer-side storage portion 53a of the developing unit 50 communicate with each other via the discharge opening 71b and the receiving opening 53b. When toner is replenished from the cartridge 70 to the developing unit 50, at least a portion of the receiving opening 53b is positioned below at least a portion of the discharge opening 71b.

[0034] The toner contained in the toner container 71a is then discharged from the discharge opening 71b, and the toner discharged from the discharge opening 71b is received in the developer-side container 53a through the receiving opening 53b. The toner contained in the developer-side container 53a is supplied to the developing roller 51 by the supply roller 52. The toner contained in the toner container 71a is supplied to the developing roller 51 through this route.

[0035] The cartridge 70 may have a sealing member (first sealing member) not shown that covers the discharge opening 71b. The developing unit 50 may have a sealing member (second sealing member) not shown that covers the receiving opening 53b. When the cartridge 70 is not attached to the developing unit 50, the cartridge 70 and the developing unit 50 may be configured so that the discharge opening 71b and the receiving opening 53b are covered with sealing members, respectively, to prevent toner from leaking out from the discharge opening 71b and the receiving opening 53b.

[0036] <Image formation operation> The image forming operation in this embodiment will be described. First, the photosensitive drum 2 is rotated in the direction of the arrow (counterclockwise) in Fig. 1 in synchronization with the rotation of the intermediate transfer belt 10a. Then, the surface of the photosensitive drum 2 is uniformly charged by the charging roller 3.

[0037] When a color image is formed on the sheet S, the rotary body 90 rotates in the direction of the arrow in Figure 1 (clockwise) while supporting the developing units 50y, 50m, 50c, and 50k, as follows: Then, the electrophotographic process is repeatedly performed while the developing rollers 51y, 51m, 51c, and 51k are moved one by one to the developing position.

[0038] First, the scanner 4 irradiates the photosensitive drum 2 with laser light based on image data corresponding to a yellow image, forming an electrostatic latent image corresponding to the yellow image on the surface of the photosensitive drum 2. In parallel with the formation of this electrostatic latent image, the motor M1 rotates the rotary body 90 to place the rotary body 90 in a yellow developing position. When the rotary body 90 is in the yellow developing position, the developing roller 51y is in the developing position, and develops the electrostatic latent image formed on the photosensitive drum 2 with yellow toner.

[0039] In this embodiment, each of the developing rollers 51y, 51m, 51c, and 51k is an elastic roller having a metal shaft coated with rubber. At the developing position, each of the developing rollers 51y, 51m, 51c, and 51k develops an electrostatic latent image while in contact with the photosensitive drum 2. In other words, the image forming apparatus 1 in this embodiment employs a contact development system. However, each of the developing rollers 51y, 51m, 51c, and 51k may also develop an electrostatic latent image while a gap is provided between the developing rollers 51y, 51m, 51c, and 51k and the photosensitive drum 2 at the developing position. In other words, the image forming apparatus 1 may employ a non-contact development system.

[0040] When the yellow toner image is developed, the yellow toner image on the photosensitive drum 2 is primarily transferred onto the intermediate transfer belt 10a by the primary transfer roller 11 arranged inside the intermediate transfer belt 10a.

[0041] Thereafter, the rotary body 90 is rotated to move the developing rollers 51m, 51c, and 51k to the developing positions in order, thereby forming toner images of each color. That is, after a yellow toner image is formed on the intermediate transfer belt 10a, the rotary body 90 takes the magenta developing position, 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 body 90 takes the cyan developing position, 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 body 90 takes the black developing position, and a black toner image is formed on the intermediate transfer belt 10a.

[0042] Then, the primary transfer is repeated so that the four color toner images are superimposed on the intermediate transfer belt 10a, thereby forming a color image on the intermediate transfer belt 10a. Note that, until the color image is formed on the intermediate transfer belt 10a, the secondary transfer roller 12 and the cleaning device 13 are not in contact with the intermediate transfer belt 10a.

[0043] Meanwhile, sheets S are fed by a pickup roller 310 from a sheet storage unit 300 provided at the bottom of the apparatus main body 1A. The sheets S are separated into individual sheets by a feed roller 311 and a separation roller 312 and then fed to a pair of conveying rollers 320. The pair of conveying rollers 320 sends the fed sheets S to a transfer area (secondary transfer area), which is a nip area between the intermediate transfer belt 10a and the secondary transfer roller 12. The color image on the intermediate transfer belt 10a is transferred (secondary transfer) onto the surface of the conveyed sheet S.

[0044] The sheet S onto which the color image has been transferred is sent to the fixing device 40. In the fixing device 40, the sheet S is heated and pressurized, and the image is fixed onto the sheet S. After passing through the fixing device 40, the sheet S is discharged outside the image forming apparatus 1 as a finished product.

[0045] On the other hand, when a monochrome image is formed on the sheet S, the rotary body 90 takes the black developing position. In this state, an electrostatic latent image is formed on the surface of the photosensitive drum 2 by charging and exposing the photosensitive drum 2, and then the electrostatic latent image is developed with black toner by the developing roller 51k positioned at the developing position. The black toner image is primarily transferred to the intermediate transfer belt 10a, and then secondarily transferred to the sheet S. The subsequent steps are the same as those for color images.

[0046] <Rotary configuration> The configuration of the rotary body 90 will be described using Figures 1, 4(A), 4(B), and 5. Figures 4(A) and 4(B) are cross-sectional views showing the rotary body 90 and its surroundings of the image forming apparatus 1. Figures 4(A) and 4(B) are cross-sectional views of the apparatus cut along an imaginary plane perpendicular to the rotation axis 90C of the rotary body 90. Figure 5 is a perspective view of the rotary body 90.

[0047] As described above, the cartridges 70y to 70k are detachable from the rotary body 90. When the toner in the cartridges 70y to 70m runs out, the user can replenish the image forming apparatus 1 with toner by replacing the cartridges 70y to 70k.

[0048] 1, the apparatus main body 1A has a frame 16 that houses the rotary main body 90. The frame 16 is the main body frame of the image forming apparatus 1 of this embodiment. The frame 16 is the housing (skeleton) of the apparatus main body 1A that is composed of a frame and exterior members, and is approximately rectangular in shape in this embodiment.

[0049] The frame 16 has an opening 16a. More specifically, the frame 16 has a side surface 16b that extends in a direction intersecting the horizontal direction. The side surface 16b constitutes at least a part of the exterior surface on the +X side of the device main body 1A. The opening 16a is located on this side surface 16b. The side surface 16b is located downstream of the discharge port in the discharge direction in which the sheets S on which images are formed are discharged from the discharge port of the device main body 1A. A user can access the sheet storage unit 300 from the side surface 16b of the image forming apparatus 1 to refill the sheets S or retrieve the sheets S discharged from the discharge port. Therefore, the side surface 16b can be said to be the front surface (front face) of the device main body 1A.

[0050] In this embodiment, the cartridges 70y, 70m, 70c, and 70k are supported by the trays 80y to 80k and are attached to and detached from the rotary body 90 through the opening 16a. In other words, the user can attach and detach the cartridges 70y to 70k to and from the rotary body 90 via the trays 80y to 80k.

[0051] The opening 16a is disposed on a side surface 16b of the frame body 16. The side surface 16b is a surface that is approximately parallel to the rotation axis 90C of the rotary body 90. Therefore, when the cartridge 70 is replaced, the cartridge 70 passes through the opening 16a in a direction intersecting (preferably perpendicular to) the rotation axis 90C.

[0052] Image forming apparatus 1 has door 14 that covers opening 16a of frame 16. Door 14 is an openable / closable member that can be moved between a closed position (see also FIG. 6(A)) that covers opening 16a and an open position (see also FIGS. 6(B) and 6(C)) that exposes opening 16a.

[0053] As described above, in this embodiment, the cartridge 70 is configured to be detachable from the rotary body 90 via the tray 80. Therefore, the cartridge 70 can be detachable from the rotary body 90 in a stable manner.

[0054] More specifically, the user can replace the cartridge 70 by inserting or removing the cartridge 70 into or from a tray 80 that is configured to be movable relative to the rotary body 90 (i.e., relative to the apparatus main body 1A). As a comparative example, in a configuration in which the user replaces the cartridge by directly inserting or removing the cartridge into or from the apparatus main body, the user is required to insert the cartridge to a predetermined mounting position within the apparatus main body. In this embodiment, the tray 80 is movable so that the cartridge 70 moves to the mounting position while supporting the cartridge 70. Therefore, the user can replace the cartridge 70 by the simple operation of placing the cartridge 70 on the tray 80, improving operability.

[0055] The cartridge 70 has an elongated shape with its longitudinal direction being the Y direction parallel to the rotation axis 90C of the rotary body 90. In other words, the longitudinal dimension of the cartridge 70 is greater than the height and width of a cross section perpendicular to the longitudinal direction. When handling such an elongated cartridge 70, by arranging the opening 16a on the side surface 16b of the frame 16 that is approximately parallel to the longitudinal direction (Y direction) of the cartridge 70, the cartridge 70 can pass through the opening 16a in a short moving distance. For example, this makes it easier to replace the cartridge 70 than when inserting or removing the cartridge 70 through an opening provided on the side surface of either one side (+Y side or −Y side) of the frame 16 in the longitudinal direction of the cartridge 70.

[0056] The rotary body 90 can rotate about a rotation axis 90C and assume replacement positions that allow removal of any of the cartridges 70y to 70k from the rotary body 90. The position that allows removal of the cartridge 70y is called the yellow replacement position. The position that allows removal of the cartridge 70m is called the magenta replacement position. The position that allows removal of the cartridge 70c is called the cyan replacement position. The position that allows removal of the cartridge 70k is called the black replacement position.

[0057] 4A shows a cross section of the rotary body 90 in a developing position (specifically, a yellow developing position), and FIG. 4B shows a cross section of the rotary body 90 in a replacement position (specifically, a black replacement position).

[0058] As shown in Figures 4(A) and 4(B), four trays 80y to 80k are attached to the rotary body 90. The trays 80y to 80k hold cartridges 70y to 70k, respectively. In Figures 4(A) and 4(B), the trays 80y to 80k and cartridges 70y to 70k are housed inside the rotary body 90. This state can be said to be the state in which the cartridges 70y to 70k are attached to the development units 50y, 50m, 50c, and 50k.

[0059] When the cartridge 70 is in the mounting position relative to the developing frame 53, the discharge opening 71b and the receiving opening 53b face each other, as shown in Fig. 3. In this state, the cartridge 70 is configured to supply toner to the developing-side accommodating portion 53a through the receiving opening 53b (the opening in the accommodating frame).

[0060] The apparatus main body 1A has a moving device 85 configured to move the cartridge 70 from an attached position to a retracted position relative to the rotary main body 90 (more specifically, relative to the developing frame 53 of the developing unit 50). The moving device 85 will be described later using FIG. 8 and other figures. In this embodiment, the rotary main body 90 is provided with a plurality of moving devices 85y-85k corresponding to the plurality of cartridges 70y-70k. It can be said that the trays 80y-80k are part of these moving devices 85y-85k.

[0061] In this embodiment, the cartridge 70k containing black toner is larger in size than the cartridges 70y to 70c containing yellow toner, magenta toner, and cyan toner, and can contain more toner.

[0062] Specifically, the length of the black cartridge 70k in a first radial direction relative to the rotation axis 90C of the rotary body 90 is greater than the length of the magenta cartridge 70m in a second radial direction. Here, the first radial direction is the rotation radius direction of the rotary body 90 (the radial direction of an imaginary circle centered on the rotation axis 90C), and is the direction in which the cartridge 70k extends relative to the rotation axis 90C when viewed in the direction of the rotation axis 90C. The second radial direction is the rotation radius direction of the rotary body 90, and is the direction in which the cartridge 70m extends relative to the rotation axis 90C when viewed in the direction of the rotation axis 90C. Similarly, the length of the black cartridge 70k in the first radial direction is greater than the lengths of the cartridges 70y, 70c in the radial directions corresponding to the other cartridges 70y, 70c.

[0063] Therefore, the tray 80k that holds the black cartridge 70k is larger in size than the trays 80y to 80c that hold the other cartridges 70y, 70m, and 70c. That is, four cartridges 70y to 70k and trays 80y to 80k of different sizes are arranged inside the rotary body 90.

[0064] Here, the rotational drive of the rotary body 90 will be described with reference to Figure 5. As shown in Figure 5, disk gears 92L and 92R are formed at both ends of the rotary body 90. Furthermore, rotary drive gears 93L and 93R are connected to both ends of the oscillating shaft 91 so as to be capable of transmitting drive power. Here, the drive force of the motor M1 is transmitted to the rotary drive gear 93R by a drive transmission mechanism. Next, the drive force is transmitted to the disk gears 92L and 92R by the rotary drive gears 93L and 93R, thereby rotating the rotary body 90.

[0065] The rotary body 90 is supported so as to be able to swing about a swing shaft 91. The rotary body 90 is urged by a biasing member (not shown) in the counterclockwise direction in FIGS. 4A and 4B around the swing shaft 91. This direction can be said to be the direction in which each of the developing rollers 51y to 51k approaches the photosensitive drum 2. As a result, when the rotary body 90 is in the developing position, each of the developing rollers 51y to 51k abuts against the photosensitive drum 2.

[0066] 5, rotary cams 90eL and 90eR are provided at both ends of the rotary body 90. When the rotary body 90 rotates clockwise in FIGS. 4A and 4B around the rotation axis 90C, the rotary cams 90eL and 90eR come into contact with a roller 96 (FIGS. 4A and 4B) supported by the frame 16. Then, the rotary cams 90eL and 90eR move clockwise in FIGS. 4A and 4B around the swing shaft 91. This direction can be said to be the direction in which each of the developing rollers 51y to 51k moves away from the photosensitive drum 2. This direction can also be said to be the direction in which the rotary body 90 approaches the opening 16a of the frame 16 and the door 14.

[0067] As a result, when the rotary body 90 rotates and switches from the developing position to the replacement position, the rotary body 90 swings around the swing shaft 91. When the rotary body 90 is in the replacement position, the developing roller 51 is separated from the photosensitive drum 2.

[0068] 4(B), in the black replacement position, the cartridge 70k stops at a position facing the opening 16a provided in the side surface 16b of the apparatus main body 1A and the door 14. From this state, when the tray 80k is slid from the attachment position to the developing unit 50k to the outside of the rotary main body 90, the user can replace the cartridge 70k.

[0069] <Cartridge replacement operation> The cartridge replacement operation will be described using Figures 4(A), 6(A) to 6(C), and 7(A) and 7(B). Figures 6(A) to 6(C) are external views of the device main body 1A. Figures 7(A) and 7(B) are cross-sectional views of the rotary body 90 and its surroundings during cartridge replacement. Figures 7(A) and 7(B) are cross-sectional views of the device taken along an imaginary plane perpendicular to the rotation axis 90C of the rotary body 90.

[0070] Fig. 6(A) shows the appearance of the apparatus main body 1A during image forming operation and in standby state. During image forming operation, the image forming apparatus 1 performs a series of operations from feeding the sheet S, forming an image on the sheet S, to discharging the sheet S as a finished product. The standby state is a state in which the image forming apparatus 1 is ready to start image forming operation upon receiving an image formation instruction (print instruction), and is waiting for an image formation instruction from the user. As shown in Fig. 6(A), during image forming operation and in standby state, the door 14 is closed.

[0071] 6(B) shows the appearance of the apparatus main body 1A when the cartridge is replaced. When the cartridge is replaced, the door 14 is opened, and the tray 80 and the cartridge 70 are moved to the outside of the apparatus main body 1A.

[0072] The cartridge 70 is movable between an attached position and a retracted position retracted from the attached position relative to the developing frame 53 of the developing unit 50. When the cartridge 70 is in the attached position relative to the developing frame 53, the discharge opening 71b and the receiving opening 53b face each other, as shown in Figure 3. As shown in Figures 4(A) and 4(B), the rotary body 90 is configured to rotate about a rotation axis 90C when the cartridge 70 is in the attached position, and to assume a developing position or an exchange position.

[0073] The replacement of a cartridge will now be described. First, when a user instructs the image forming apparatus 1 to replace a cartridge 70, the rotary body 90 rotates until it assumes the replacement posture corresponding to the cartridge 70 to be replaced, and then stops. In other words, the image forming apparatus 1 rotates the rotary body 90 so that it assumes the replacement posture corresponding to the cartridge 70 to be replaced. With the rotary body 90 in the replacement posture, the tray 80 supporting the cartridge 70 to be replaced faces the opening 16a of the frame 16 of the apparatus main body 1A.

[0074] For example, the rotary body 90 in FIG. 4A is in a yellow developing position in which the yellow developing roller 51y faces the photosensitive drum 2. At this time, the black cartridge 70k and tray 80k do not need to face the opening 16a and the door 14. The opening 16a need only be large enough to allow each cartridge 70 to pass through individually. When the rotary body 90 rotates a predetermined angle clockwise in the drawing from the yellow developing position, the black cartridge 70k and tray 80k face the opening 16a and the door 14, as shown in FIG. 4B.

[0075] Here, "the tray 80 faces the opening 16a" means that the tray 80 is positioned so as to be movable to the outside of the apparatus main body 1A via the opening 16a. In other words, when the tray 80 faces the opening 16a, the tray 80 is moved radially outward of the rotary body 90 by a moving device (described later), allowing the tray 80 and the cartridge 70 supported by the tray 80 to protrude to the outside of the apparatus main body 1A. In FIG. 4A, none of the trays 80y to 80k faces the opening 16a. In FIG. 4B, only the black tray 80k faces the opening 16a, and the other trays 80y to 80c do not face the opening 16a.

[0076] With the rotary body 90 positioned in the replacement posture, the tray 80 supporting the cartridge 70 to be replaced is moved toward the outside of the apparatus main body 1A by the motor M2. As a result, the cartridge 70 to be replaced moves from the mounting position to the retracted position relative to the rotary body 90. Furthermore, as shown in Figures 6(B), 6(C), 7(A), and 7(B), the tray 80 and the cartridge 70 to be replaced supported by the tray 80 protrude to the outside of the apparatus main body 1A through the opening 16a.

[0077] More specifically, the tray 80 is movable between a storage position and an ejection position relative to the rotary body 90. The storage position is a position where the tray 80 is stored within the rotary body 90. The ejection position is a position where the tray 80 protrudes outside the rotary body 90 and the cartridge 70 can be ejected from the tray 80 (removal position, replaceable position). Examples of storage positions are the positions of the trays 80y to 80k in Figures 4(A) and 4(B). Examples of ejection positions are the positions of the tray 80 in Figures 6(B) and 6(C), the tray 80k in Figure 7(A), and the tray 80m in Figure 7(B).

[0078] When the tray 80 is in the storage position, the cartridge 70 attached to the tray 80 is in the loading position. When the tray 80 is in the ejection position, the cartridge 70 attached to the tray 80 is in the retracted position.

[0079] 7(A) and 7(B), the rotary body 90 has a protrusion 95 for holding the tray 80 in the storage position and for holding the cartridge 70 in the mounting position. As shown in Fig. 8, the tray 80 is provided with a recess 87 that fits into the protrusion 95. Figs. 7(A) and 7(B) show protrusions 95k and 95m corresponding to trays 80k and 80m, and Fig. 8 shows recesses 87y and 87m of trays 80y and 80m, but the protrusion 95 and recess 87 are provided for each of the trays 80y to 80k.

[0080] The convex portion 95 fits into the concave portion 87 of the tray 80, thereby locking the tray 80 to the rotary frame body 90f. This allows the tray 80 to remain in the storage position even when the rotary body 90 rotates, preventing the cartridge 70 from moving from the installation position. When the tray 80 is moved between the storage position and the removal position by a moving device described below, the tray 80 can move by climbing over the convex portion 95.

[0081] In this embodiment, the door 14 is rotatably supported relative to the apparatus main body 1A. As shown in Fig. 7(A), the door 14 is biased from the open position toward the closed position by a spring 14s. The spring 14s is, for example, a tension spring, and biases the door 14 so as to generate a moment in the counterclockwise direction in Fig. 7(A) about the support shaft 14c of the door 14.

[0082] When the tray 80 pushes the door 14, the door 14 enters an open state (the state shown in FIG. 6(B)). This state can also be said to be a state in which the tray 80 is supported by the door 14. By the door 14 supporting at least a portion of the tray 80 that protrudes outside the apparatus main body 1A, the cartridge 70 can be supported more stably.

[0083] In addition, the door 14 is configured to abut against a part of the frame 16 of the device main body 1A (for example, the lower edge 16c of the opening 16a) in the open position, so as not to rotate downward beyond the open position. When the tray 80 is pulled back from the outside to the inside of the device main body 1A, the biasing force of the spring 14s causes the door 14 to return to the closed position.

[0084] The cartridge 70 is detachably held in the tray 80. Therefore, as shown in Fig. 6(C), the user can remove the cartridge 70 from the tray 80 and install a new cartridge 70 (replacement work). When replacing multiple cartridges 70, the replacement work can be performed by repeating the above operation.

[0085] 7A and 7B show cross sections of the rotary body 90 and its surroundings when replacing the cartridges. Fig. 7A shows the state when the black cartridge 70k is replaced, and Fig. 7B shows the state when the magenta cartridge 70m is replaced.

[0086] The image forming apparatus 1 includes a moving device 85 (FIG. 8) that moves the cartridge 70 from the mounting position to the retracted position. In this embodiment, the moving device 85 can be said to include the tray 80.

[0087] Even when the cartridge 70 is in the retracted position, the tray 80 remains connected to the rotary body 90 (is supported by the rotary body 90). To easily remove the cartridge 70 from the rotary body 90, it is preferable that the length by which the cartridge 70 protrudes from the rotary body 90 in the retracted position is long. Because the cartridge 70 is configured to be detachable from the rotary body 90 via the tray 80, the cartridge 70 can be stably supported by the tray 80 even when the length by which the cartridge 70 protrudes from the rotary body 90 is long.

[0088] The direction in which the cartridge 70 moves from the mounted position to the retracted position is referred to as the retraction direction. In this embodiment, the retraction direction of the cartridge 70 is a direction intersecting the direction of the rotation axis 90C (Y direction). Therefore, as shown in Figures 7(A) and 7(B), when viewed in the direction of the rotation axis 90C (Y direction), the retraction direction of the cartridge 70 is a direction perpendicular to the direction of the rotation axis 90C (Y direction). Furthermore, the retraction direction of the cartridge 70 can be said to be a direction toward the outside in the rotational radius direction of the rotary body 90 (a direction away from the rotation axis 90C).

[0089] 7(A) and 7(B), since the user removes the cartridge 70 from the rotary body 90, it is preferable that at least a portion of the cartridge 70 protrudes from the rotary body 90 when the cartridge 70 is removed. In this embodiment, when the cartridge 70 is in the retracted position, the entire cartridge 70 protrudes from the rotary body 90.

[0090] When the rotary body 90 rotates around the rotation axis 90C, the rotation locus of the rotary body 90 coincides with a circumscribing circle (imaginary circle 90V shown by a dashed line in FIGS. 7A and 7B) of the rotary body 90 centered on the rotation axis 90C. When the cartridge 70 is in the retracted position, it is preferable that more than half of the length of the cartridge 70 in the retraction direction is outside the rotation locus of the rotary body 90. In other words, when viewed in the direction of the rotary's rotation axis, it is preferable that, with the cartridge 70 in the retracted position, more than half of the total length of the cartridge is located outside the rotation locus of the rotary in the direction of movement of the cartridge from the mounted position toward the retracted position. Furthermore, in this embodiment, as shown in FIGS. 7A and 7B, when the cartridge 70 is in the retracted position, the entire cartridge 70 is outside the rotation locus (imaginary circle 90V) of the rotary body 90.

[0091] Furthermore, in order to make it easier for the user to grasp the cartridge 70, it is preferable that at least a part of the cartridge 70 is outside the image forming apparatus 1 (outside the apparatus main body 1A) when the cartridge 70 is in the retracted position. Here, "outside the apparatus" refers to the space outside the image forming apparatus 1 (outside the apparatus main body 1A) when the image forming apparatus 1 is being used, for example, for forming an image on a sheet S.

[0092] In this embodiment, the exterior surface of the apparatus main body 1A is formed by the exterior surface of the frame 16. In other words, the outside of the apparatus can also be referred to as the outside of the frame 16. Therefore, a state in which at least a part of the cartridge 70 is outside the apparatus can also be referred to as a state in which at least a part of the cartridge 70 protrudes from the opening 16a of the frame 16 of the apparatus main body 1A toward the outside of the frame 16.

[0093] In this embodiment, when the door 14 is in the closed position, the opening 16a of the frame 16 of the apparatus main body 1A is covered by the door 14. The exterior surface 14a of the door 14 in the closed position forms part of the exterior surface of the apparatus main body 1A. In this case, the outside of the apparatus refers to the area outside the exterior surface 14a of the door 14 in the closed position. In other words, if the position of the exterior surface 14a of the door 14 in the closed position is defined as the exterior position, then when the cartridge 70 is in the retracted position, at least a part of the cartridge 70 is located outside the apparatus main body 1A beyond this exterior position.

[0094] In other words, at least a part of the cartridge 70 is positioned in the space that would be outside the apparatus main body 1A if the door 14 were in the closed position. In addition, with respect to the retraction direction of the cartridge 70, at least a part of the cartridge 70 is located downstream of the visible position.

[0095] Furthermore, when the side surface 16b on which the opening 16a is provided is the front surface of the apparatus main body 1A and the cartridge 70 is in the retracted position, at least a portion of the cartridge 70 protrudes forward beyond the exterior surface on the front side of the apparatus main body 1A. In this case, the user can easily access the cartridge 70 from the front side of the image forming apparatus and replace the cartridge 70.

[0096] When the cartridge 70 is in the retracted position, it is preferable that at least half of the length of the cartridge 70 in the retracted direction is located outside the apparatus. In other words, when viewed in the direction of the rotary's rotation axis, it is preferable that at least half of the overall length of the cartridge 70 is located outside the main body frame in the direction of movement of the cartridge 70 from the installed position toward the retracted position when the cartridge 70 is in the retracted position. It is also more preferable that the entire cartridge 70 is located outside the apparatus when the cartridge 70 is in the retracted position. In this embodiment, the exterior surface 14a and the side surface 16b of the door 14 form the exterior surface on the front side of the apparatus main body 1A, but the configuration of the door 14 is not limited to this. For example, the size of the door 14 may be such that it covers the entire side surface 16b. In this case, the exterior surface 14a of the door 14 forms the exterior surface on the front side of the apparatus main body 1A.

[0097] The tray 80 has a cartridge holding portion 81 (see Figures 3 and 6(C)) that holds the cartridge 70. The cartridge holding portion 81 is a mounting portion onto which the cartridge 70 is mounted. When the tray 80 is in the removal position, it is preferable that the entire cartridge holding portion 81 is outside the rotation trajectory of the rotary body 90 in the retraction direction. When the tray 80 is in the removal position, it is preferable that more than half of the length of the cartridge holding portion 81 is outside the machine in the retraction direction.

[0098] As described above, the cartridge 70k and the tray 80k are larger in size than the other cartridges 70y to 70c and trays 80y to 80c. Therefore, in this embodiment, as shown in Figures 7(A) and 7(B), the amount of movement of the tray 80 during cartridge replacement is changed according to the size of the cartridge 70.

[0099] Specifically, as shown in Figure 7(A), the movement distance of tray 80k when it moves from the storage position to the removal position is L1. The movement distance of tray 80m when it moves from the storage position to the removal position is L2. Figure 7(B) shows a state in which cartridge 70m and tray 80m have moved, but the movement distance of trays 80y and 80c when they move from the storage position to the removal position is also L2. In this case, L1 is greater than L2.

[0100] 7(A), when the tray 80k is in the ejection position and the cartridge 70k is in the retracted position, the cartridge 70k protrudes from the exterior surface of the apparatus main body 1A by a distance P1. In this embodiment, the tray 80k also protrudes from the exterior surface of the apparatus main body 1A by a distance P1.

[0101] 7(B), when the tray 80m is in the ejection position and the cartridge 70m is in the retracted position, the cartridge 70m protrudes from the exterior surface of the apparatus main body 1A by a distance P2. In this embodiment, the tray 80m also protrudes from the exterior surface of the apparatus main body 1A by a distance P2. The cartridges 70y and 70c also protrude from the exterior surface of the apparatus main body 1A by a distance P2. The distance P1 is greater than the distance P2.

[0102] For cartridges 70y-70c, which are smaller in size than cartridge 70k, it is preferable from the standpoint of strength to make the distance P2 by which cartridge 70y-70c protrudes outside the apparatus when in the retracted position shorter than the distance P1 by which cartridge 70k protrudes outside the apparatus when in the retracted position. This is for the following reason: When cartridge 70 is located in the retracted position, at least a portion of cartridge 70 protrudes outside the apparatus outside the rotation path of the rotary body 90 or from the external surface of the apparatus main body 1A. At this time, the tray 80 supports the weight of cartridge 70 while being cantilevered by the rotary body 90. Therefore, shortening the distance P2 by which cartridges 70y-70c protrude outside the apparatus when in the retracted position reduces the load on trays 80y-80c and the guide portion 97 of the rotary body 90 that supports trays 80y-80k. Furthermore, because cartridges 70y-70c are smaller in size than cartridge 70k, the ease of cartridge replacement for trays 80y-80c can be maintained even if distance P2 is shorter than distance P1.

[0103] <Tray arrangement in the rotary> The arrangement of the trays 80y to 80k in the rotary body 90 will be described using Figures 8, 9, and 10. Figure 8 is a perspective view showing the arrangement of the trays 80y to 80k in the rotary body 90. Figure 9 is a cross-sectional view showing the arrangement of the trays 80y to 80k in the rotary body 90. Figure 10 is a view showing the arrangement of components at one end of the trays 80y to 80k in the Y direction. Figure 9 shows a cross-section of the rotary body 90 in an imaginary plane perpendicular to the rotation axis 90C of the rotary body 90. The upper half of Figure 10 is a view of the rotary body 90 and trays 80m and 80k in Figure 8 as seen from the upper right side (+Z side) of Figure 8, and the lower half of Figure 10 is a view of the rotary body 90 and trays 80c and 80y in Figure 8 as seen from the left side (-X side) of Figure 8.

[0104] As shown in FIG. 8, the trays 80y to 80k are each provided with cartridge holding portions 81y to 81k and guided portions 82y to 82k.

[0105] The cartridges 70y to 70k are attached to the cartridge holding portions 81y to 81k, respectively. Each of the cartridge holding portions 81y to 81k accommodates at least a portion of the cartridges 70y to 70k attached thereto.

[0106] The guided portions 82y to 82k are provided at both ends of the trays 80y to 80k, sandwiching the cartridge holding portions 81y to 81k in the Y direction. Each of the guided portions 82y to 82k is an elongated member that extends in a direction perpendicular to the rotation axis of the rotary body 90.

[0107] In this embodiment, a reinforcing rib 82k1 is formed on a portion of the guided portion 82k in the movement direction Dk of the tray 80k, and a reinforcing rib 82m1 is formed on a portion of the guided portion 82m in the movement direction Dm of the tray 80m (see also FIGS. 11(A) and 11(B)). The reinforcing ribs 82k1, 82m1 are rib-shaped (protruding stripes) that protrude outward in the Y direction from the guided portions 82k, 82m provided at both ends of the trays 80k, 80m in the Y direction and extend in the movement directions Dk, Dm of the trays 80k, 80m. The reinforcing ribs 82k1, 82m1 improve the rigidity of the guided portions 82k, 82m.

[0108] In this embodiment, the lengths of the reinforcing ribs 82m1 and 82k1 are limited to avoid the guided portions 82y and 82c, but the reinforcing ribs 82m1 and 82k1 may be provided over the entire length of the guided portions 82m and 82k if there is no interference with the guided portions 82y and 82c. Reinforcing ribs may also be added to the guided portions 82y and 82c. Furthermore, if the rigidity of the guided portions 82m and 82k is sufficient, the reinforcing ribs 82m1 and 82k1 may not be provided.

[0109] Rack portions 83y to 83k (rack gears) are formed on the guided portions 82y to 82k. Pinion gears 94y to 94k are rotatably held within the rotary body 90. The pinion gears 94y to 94k are engaged with the rack portions 83y to 83k, respectively, so as to be capable of transmitting driving force.

[0110] The rack portions 83y-83k and pinion gears 94y-94k are part of moving devices 85y-85k configured to move the cartridges 70y-70k from the mounting position to the retracted position. The rack portions 83y-83k and pinion gears 94y-94k can be considered to be part of a driven device that is driven by a drive device 98 of the apparatus main body 1A. The pinion gears 94y-94k can be considered to be rotating bodies (rotating members) that rotate to move the trays 80y-80k relative to the rotary main body 90.

[0111] The pinion gears 94y to 94k and the rack portions 83y to 83k function as driven portions for the moving devices 85y to 85k of the rotary body 90 to receive a driving force from the driving device 98 of the apparatus main body 1A.

[0112] The rotary body 90 has guide portions 97 (see FIGS. 7(A) and 7(B)) that engage with each of the guided portions 82y to 82k. FIG. 7(A) shows the guide portion 97 (97k) that engages with the guided portion 82k of tray 80k, and FIG. 7(B) shows the guide portion 97 (97m) that engages with the guided portion 82m of tray 80m. The rotary body 90 is provided with similar guide portions that engage with the guided portions 82y and 82c of trays 80y and 80c. Also, while FIGS. 7(A) and 7(B) show the guide portion 97 provided on one side (+Y side) of the rotary body 90 in the Y direction, a similar guide portion 97 is also provided on the other side (-Y side) of the rotary body 90 in the Y direction.

[0113] When tray 80 moves between the storage position and the removal position, guide portion 97 maintains an engaged state with guided portion 82 over at least a portion of the movement range, guiding the movement direction of tray 80. In this embodiment, guide portion 97 maintains an engaged state with guided portion 82k over the entire movement range of tray 80k between the storage position and the removal position. Also, in this embodiment, guide portion 97 maintains an engaged state with guided portion 82m over the entire movement range of tray 80m between the storage position and the removal position.

[0114] As shown in FIGS. 8 and 9, four trays 80y to 80k are arranged inside the rotary body 90 so as to overlap one another, as will be described in detail below.

[0115] When the pinion gears 94y-94k rotate, the rack portions 83y-83k and the trays 80y-80k move relative to the rotary body 90. As shown in Fig. 9, the four trays 80y-80k are arranged so that their movement directions are rotated by 90 degrees relative to the rotary body 90. Therefore, the trays 80y and 80c, and the trays 80m and 80k are held so that they can slide in substantially the same direction (parallel directions). The movement direction of each of the trays 80y-80k during sliding movement is regulated by the engagement between the guided portions 82y-82k and the guide portion 97.

[0116] The trays 80y to 80k move to the outside of the apparatus through the opening 16a. When each of the trays 80y to 80k moves to the outside of the apparatus through the opening 16a, the movement directions of the respective trays are substantially the same direction (parallel).

[0117] 9, in the movement direction Dk of tray 80k, the range in which tray 80k is arranged overlaps with the range in which tray 80y and tray 80c are arranged. Furthermore, in the movement direction Dk of tray 80k, the range in which tray 80k is arranged overlaps with the rotation axis 90C of the rotary body 90. In other words, it can be said that cartridge 70k held in cartridge holding portion 81k of tray 80k overlaps with the rotation axis 90C of the rotary body 90 (FIG. 4(B)).

[0118] On the other hand, in the direction Dm of movement of tray 80m, the range in which tray 80m is arranged is shifted so as not to overlap with the range in which tray 80y is arranged and the range in which tray 80c is arranged. Furthermore, in the direction Dy of movement of tray 80y, the range in which tray 80y is arranged is shifted so as not to overlap with the range in which tray 80m is arranged and the range in which tray 80k is arranged. Similarly, in the direction Dc of movement of tray 80c, the range in which tray 80c is arranged is shifted so as not to overlap with the range in which tray 80m is arranged and the range in which tray 80k is arranged.

[0119] The positional relationship between the trays 80 can also be expressed as follows: When viewed in the movement direction Dy of tray 80y, tray 80y and tray 80k overlap, but tray 80y and tray 80m do not overlap. When viewed in the movement direction Dm of tray 80m, tray 80m and tray 80k overlap, but tray 80m does not overlap with trays 80y and 80c. When viewed in the movement direction Dc of tray 80c, tray 80c and tray 80k overlap, but tray 80c and tray 80m do not overlap.

[0120] Here, when two elements (components, parts, units, etc.) overlap when viewed in a particular direction, this means that when each element is vertically projected onto an imaginary plane perpendicular to that direction, the projection area of ​​one element at least partially overlaps with the projection area of ​​the other element.

[0121] 8 and 10, in the direction of rotation axis 90C (Y direction), the range in which rack portion 83m and guided portion 82m are arranged at least partially overlaps with the range in which rack portion 83k and guided portion 82k are arranged. Therefore, compared to an arrangement in which rack portion 83m and guided portion 82m do not overlap with rack portion 83k and guided portion 82k, rack portions 83m, 83k and guided portions 82m, 82k can be arranged in a more space-saving manner in the Y direction.

[0122] In the direction of rotation axis 90C (Y direction), the range in which rack portion 83y and guided portion 82y are arranged at least partially overlaps with the range in which rack portion 83c and guided portion 82c are arranged. Therefore, compared to an arrangement in which rack portion 83y and guided portion 82y do not overlap with rack portion 83c and guided portion 82c, rack portions 83y, 83c and guided portions 82y, 82c can be arranged in a more space-saving manner in the Y direction.

[0123] Here, the meshing position between the rack portion 83 and the pinion gear 94 will be described with reference to Figure 10. The upper half of Figure 10 shows the meshing position between the rack portion 83k and the pinion gear 94k. The lower half of Figure 10 shows the meshing position between the rack portion 83y and the pinion gear 94y.

[0124] In the direction of the rotation axis 90C of the rotary body 90 (Y direction), in an area Y1 in the figure, a driving force transmitted from a motor M2 (FIG. 2) serving as a driving source via a transmission device (described later) is transmitted to the pinion gears 94y to 94k. In an area Y2 in the Y direction, the pinion gear 94k meshes with the rack portion 83k so as to be able to transmit driving force. In an area Y3 in the Y direction, the pinion gear 94y meshes with the rack portion 83y so as to be able to transmit driving force. Note that the rack portion 83m, like the rack portion 83k, meshes with the pinion gear 94m (FIG. 8) so as to be able to transmit driving force in the area Y2. The rack portion 83c, like the rack portion 83y, meshes with the pinion gear 94c (FIG. 8) so as to be able to transmit driving force in the area Y3.

[0125] Here, the regions Y2 and Y3 are at different positions in the Y direction (shifted in the Y direction). Also, the region Y1 is at a different position in the Y direction from both the region Y2 and the region Y3. In other words, the region Y1 is shifted in the Y direction with respect to the regions Y2 and Y3.

[0126] Furthermore, when the cartridges 70y, 70c are in the mounted position, the range in which the rack portion 83y is disposed at least partially overlaps with the range in which the rack portion 83c is disposed in the movement direction of the rack portion 83y (the movement direction Dy of the tray 80y). In this embodiment, the movement directions Dy, Dc of the trays 80y, 80c are substantially the same direction (parallel), so the range in which the rack portion 83y is disposed at least partially overlaps with the range in which the rack portion 83c is disposed in the movement direction Dc of the tray 80c as well. Therefore, when the cartridges 70y, 70c are in the mounted position, the toothed surface of the rack portion 83y and the toothed surface of the rack portion 83c face each other in the direction perpendicular to the movement directions Dy, Dc of the rack portions 83y, 83c (the left-right direction in FIG. 8).

[0127] Furthermore, when the cartridges 70m and 70k are in the mounted position, the range in which the rack portion 83m is disposed at least partially overlaps with the range in which the rack portion 83k is disposed in the movement direction of the rack portion 83m (the movement direction Dm of the tray 80m). In this embodiment, the movement directions Dm and Dk of the trays 80m and 80k are substantially the same direction (parallel), and therefore the range in which the rack portion 83m is disposed at least partially overlaps with the range in which the rack portion 83k is disposed in the movement direction Dk of the tray 80k as well. Therefore, when the cartridges 70m and 70k are in the mounted position, the toothed surfaces of the rack portions 83m and 83k face each other in the direction perpendicular to the movement directions Dm and Dk of the rack portions 83m and 83k (the up-and-down direction in FIG. 8).

[0128] 12(A) described later, when viewed in the direction of the rotation axis 90C (Y direction), rack portion 83y overlaps with rack portion 83m and rack portion 83k. When viewed in the direction of the rotation axis 90C (Y direction), rack portion 83m overlaps with rack portion 83y and rack portion 83c. When viewed in the direction of the rotation axis 90C (Y direction), rack portion 83c overlaps with rack portion 83m and rack portion 83k. When viewed in the direction of the rotation axis 90C (Y direction), rack portion 83k overlaps with rack portion 83y and rack portion 83c. In other words, in the direction of the rotation axis of the rotary (Y direction), the range in which rack portion 83k is arranged does not overlap with the range in which rack portion 83y is arranged. When viewed in the direction of the rotary axis (Y direction), the rack portion 83k and the rack portion 83y overlap with each other when the cartridge 70k is in the mounting position and the cartridge 70y is in the mounting position.

[0129] In this way, since the positions at which rack sections 83k and 83m are arranged in the Y direction are different from the positions at which rack sections 83y and 83c are arranged, rack sections 83y and 83c can be arranged so that they overlap with rack sections 83m and 83k when viewed in the Y direction.

[0130] This saves space for arranging the four trays inside the rotary body 90, making it possible to reduce the size of the rotary body 90 in the direction of its rotation radius. In other words, if the rack units 83 are arranged so as not to overlap each other as viewed in the Y direction while maintaining the movement distance of each tray 80y to 80k the same as in this embodiment, the area required for arranging the four rack units as viewed in the Y direction will be larger. Compared to this configuration, by arranging the multiple rack units 83 with their positions shifted in the Y direction and making the rack units 83 overlap each other as viewed in the Y direction, it is possible to reduce the area required for arranging the rack units 83 as viewed in the Y direction.

[0131] In this embodiment, the four rack sections 83y-83k are arranged in two pairs of two, with their positions shifted in the Y direction. That is, in the direction of the rotary's rotation axis (Y direction), the ranges in which rack section 83k and rack section 83m are arranged overlap, and the ranges in which rack section 83y and rack section 83c are arranged overlap. Furthermore, in the Y direction, the ranges in which rack section 83k and rack section 83m are arranged and the ranges in which rack section 83y and rack section 83c are arranged do not overlap. This makes it possible to reduce the size of rotary body 90 in the Y direction compared to when each of the four rack sections 83y-83k is shifted in the Y direction.

[0132] <Tray movement configuration> 11(A), 11(B), 12(A) and 12(B) will be used to explain the configuration related to the movement of trays 80y-80k arranged in the rotary main body 90. Figures 11(A) and 11(B) are perspective views showing the configuration related to the movement of tray 80k. Figures 12(A) and 12(B) are cross-sectional views showing the configuration related to the movement of tray 80k.

[0133] In this embodiment, the trays 80y-80k are all driven by the driving force of the motor M2 transmitted to pinion gears 94y-94k by drive racks 15L, 15R serving as a transmission device. Here, a configuration for moving the tray 80k relative to the rotary body 90 will be described, and a configuration for moving the trays 80y-80c relative to the rotary body 90 will not be described because it is substantially the same as the configuration for moving the tray 80k.

[0134] FIG. 11(A) shows a state in which the tray 80k is inside the rotary body 90 (i.e., a state in which the cartridge 70k is attached to the developing unit 50k). That is, FIG. 11(A) shows a state in which the tray 80k is in the storage position, which corresponds to a state in which the cartridge 70k is in the attachment position relative to the developing frame 53k (FIG. 4(A)). FIG. 11(B) shows a state in which the tray 80k has been slid to the outside of the rotary body 90. That is, FIG. 11(B) shows a state in which the tray 80k is in the removal position, which corresponds to a state in which the cartridge 70k is in the retracted position relative to the developing frame 53k (FIG. 4(B)).

[0135] The apparatus main body 1A of this embodiment has drive racks 15L and 15R as drive gears that drive the pinion gear 94. Each drive rack 15L is driven by a motor M2 via a drive transmission mechanism (not shown).

[0136] As described above, two rack portions 83k are formed at both ends of the tray 80k in the Y direction. Two pinion gears 94k and two drive racks 15L, 15R are arranged at positions corresponding to the rack portions 83k at both ends. When there is no need to distinguish between the drive racks 15L and 15R, the drive racks 15L and 15R will be collectively referred to as "drive rack 15."

[0137] That is, the rack portion 83 of this embodiment is configured as a rack gear pair, and the pinion gear 94 of this embodiment is configured as a pinion gear pair. In this embodiment, the rack gear pair and the pinion gear pair are arranged at one end side and the other end side of the support member (tray 80) in the Y direction, but they may be arranged at other positions.

[0138] One of the rack gear pair meshes with one of the pinion gear pair, and the other of the rack gear pair meshes with the other of the pinion gear pair. At least one of the pinion gear pair is driven by the drive rack 15L. In this embodiment, both of the pinion gear pair are simultaneously driven by the drive racks 15L and 15R. This makes it difficult for the tray 80 to rotate, allowing for stable movement of the cartridge 70.

[0139] Alternatively, the drive force may be input to only one of the pair of pinion gears using only the drive rack 15L. In this case, the pair of pinion gears may be connected by a shaft or the like, and the drive force may be transmitted from one of the pair of pinion gears that receives the drive force from the drive rack 15L to the other of the pair of pinion gears. This configuration eliminates the need for the drive rack 15R and the configuration for moving the drive rack 15R, making it possible to make the device smaller and simpler.

[0140] The tray 80k is held so as to be slidable relative to the rotary body 90 in a direction parallel to the guided portion 82k (i.e., the movement direction Dk). The drive rack 15 is held so as to be slidable relative to the device body 1A in a direction intersecting the movement direction Dk of the tray 80k. The drive rack 15 is configured to slide (move back and forth) relative to the device body 1A. The movement direction of the drive rack 15 in this embodiment is a direction intersecting (preferably perpendicular to) both the movement direction Dk of the tray 80k and the direction of the rotation axis 90C of the rotary body 90 (Y direction).

[0141] 11(A) and 11(B), a tray movement operation for sliding the tray 80k between the storage position and the removal position will be described. The tray movement operation of the tray 80k is performed by the motor M2 (FIG. 2), a drive transmission mechanism (not shown), the drive rack 15, the pinion gear 94k, and the rack portion 83k.

[0142] First, we will explain the tray movement operation (tray extraction operation) when removing the cartridge 70k from the rotary body 90. Before the tray extraction operation starts, the drive rack 15 is positioned below the position where it engages with the pinion gear 94k (FIG. 11(A)). Also, as mentioned above, in the replacement operation of the cartridge 70k, the rotary body 90 takes the replacement posture for the cartridge 70k (FIG. 4(B)).

[0143] When the tray extraction operation is started, the driving force of the motor M2 causes the drive rack 15 to slide upward in the apparatus main body 1A. As the drive rack 15 moves, it engages with the pinion gear 94k, and the pinion gear 94k is rotated.

[0144] As shown in Figure 11(B), when the pinion gear 94k is driven to rotate in the direction of the arrow in the figure, a driving force is input to the rack portion 83k that meshes with the pinion gear 94k. As a result, the tray 80k is pushed out of the apparatus and moves from the storage position to the removal position relative to the rotary body 90. At this time, the movement direction of the tray 80k is guided in a predetermined movement direction Dk by the engagement between the guided portion 82k and the guide portion 97k (Figure 7(A)) of the rotary body 90. As a result of the tray 80k moving from the storage position to the removal position, the cartridge 70k is moved from the installation position to the retracted position relative to the developing unit 50k.

[0145] With the tray 80k positioned at the ejection position and the cartridge 70k positioned at the retracted position, the user can attach or detach the cartridge 70k to or from the tray 80k.

[0146] The tray movement operation (tray pull-in operation, tray insertion operation) when attaching the cartridge 70 to the rotary body 90 is performed in the reverse process of the tray pull-out operation. Before the tray pull-in operation is started, the drive rack 15 is positioned above the position where it engages with the pinion gear 94k. When the operation is started, the drive force of the motor M2 causes the drive rack 15 to slide downward in the device main body 1A. Here, the rotation direction of the motor M2 in the tray pull-in operation is the opposite direction to the tray pull-out operation. As the drive rack 15 moves, it engages with the pinion gear 94k, and the pinion gear 94k is driven to rotate.

[0147] As the pinion gear 94k is driven to rotate in the direction opposite to the arrow in Figure 11(B), a driving force is input to the rack portion 83k that meshes with the pinion gear 94k. As a result, the tray 80k is drawn into the interior of the apparatus and moves from the removal position to the storage position relative to the rotary body 90. The movement direction of the tray 80k is guided in the movement direction Dk (the opposite direction to the arrow in Figure 11(B)) by the engagement between the guided portion 82k and the guide portion 97k (Figure 7(A)) of the rotary body 90. As a result of the tray 80k moving from the removal position to the storage position, the cartridge 70k is moved from the retracted position to the attached position relative to the developing unit 50k.

[0148] The movement of the black tray 80k and cartridge 70k has been described above, but the movement of the other trays 80y-80c and cartridges 70y-70c is also performed by a similar mechanism. That is, when each cartridge is in the replacement position, the drive rack 15 transmits drive to the pinion gears 94y-94c.

[0149] A drive device 98 for driving the moving device 85 provided on the rotary body 90 is configured by the motor M2 provided on the device body 1A, and a transmission device including the drive rack 15 and the drive transmission mechanism.

[0150] As described above, in this embodiment, the plurality of moving devices 85k-85y corresponding to the plurality of cartridges 70y-70k are arranged in the rotary main body 90. The driving device 98 of the apparatus main body 1A is a common driving device that drives the plurality of moving devices 85k-85y (plurality of driven devices) of the rotary main body 90.

[0151] Furthermore, in this embodiment, the rotation of the rotary body 90 switches the drive target of the drive unit 98. In other words, the drive unit of this embodiment includes a drive rack 15 as a transmission member that transmits the driving force of the drive source. The drive unit can be in a state where the transmission member is engaged with the pinion gear 94k so as to be able to transmit driving force, and a state where the transmission member is engaged with the pinion gear 94m so as to be able to transmit driving force. The drive unit can also be in a state where the transmission member is disengaged from the pinion gear 94k and the pinion gear 94m.

[0152] As described above, the pinion gears 94y to 94k are held by the rotary body 90. Therefore, when the rotary body 90 rotates, it is preferable that the engagement between the pinion gears 94y to 94k and the drive rack 15 is released.

[0153] Fig. 12(A) shows a state in which the tray 80k is inside the rotary body 90 (in the storage position), and Fig. 12(B) shows a state in which the tray 80k has moved outside the rotary body 90 (in the removal position).

[0154] As shown in Figure 12(A), when the tray 80k is inside the rotary body 90, the drive rack 15 is located at the bottom inside the device main body 1A. At this time, the drive rack 15 is retracted from the pinion gear 94k. Therefore, the drive rack 15 does not interfere with the rotation of the rotary body 90, allowing the rotary body 90 to rotate. More specifically, the drive rack 15 can be retracted outside the rotation trajectory of the rotary body 90 shown by the dotted line in Figures 12(A) and 12(B).

[0155] As described above, by driving the motor M2 to rotate in the forward and reverse directions, the tray 80 attached to the rotary body 90 can be moved from the storage position to the removal position and from the removal position to the storage position relative to the rotary body 90. In other words, the drive device of this embodiment not only drives each moving device of the rotary so that the cartridge moves from the mounting position to the retracted position, but also drives each moving device so that the cartridge moves from the retracted position to the mounting position.

[0156] <Tray status detection example> Next, an example of detecting the state of the tray 80 (tray state) when the tray 80 is moved between the storage position and the removal position will be described. FIG. 13 shows an example of detecting the tray state when the tray 80 is moved from the storage position to the removal position, and FIG. 14 shows an example of detecting the tray state when the tray 80 is moved from the removal position to the storage position. FIGS. 13(A) to 13(C) respectively show the state when the tray 80 is in the storage position, the state when the tray 80 is moving toward the removal position, and the state when the tray 80 is in the removal position. FIGS. 14(A) to 14(C) respectively show the state when the tray 80 is in the removal position, the state when the tray 80 is moving toward the storage position, and the state when the tray 80 is in the storage position. FIGS. 13(D) and 14(D) show the output of the tray detection sensor 1302, the operating state of the motor M2, and the tray state.

[0157] In the image forming apparatus 1 of this embodiment, as described above, the motor M2 is used as a drive source, and gears 131 (131a, 131b, 131c, 131d) are connected to the motor M2 so as to transmit the drive force of the motor M2. The gears 131 are connected to the rack portion 83 of the tray 80 and transmit the drive force of the motor M2 to the rack portion 83. Therefore, by driving and rotating the motor M2, the tray 80 can be moved between the storage position and the removal position. Furthermore, by moving the tray 80 with the cartridge 70 attached to it, the cartridge 70 can be moved between the attachment position and the retracted position.

[0158] The image forming apparatus 1 includes a tray detection sensor 1302 near the tray 80. The tray detection sensor 1302 is configured, for example, as a photointerrupter. A photointerrupter incorporates a light-emitting element that outputs light and a light-receiving element that receives light in a single package, and has the function of detecting an object when the object to be detected blocks light between the light-emitting element and the light-receiving element. The tray detection sensor 1302 is configured to detect the tray 80. To achieve this, sensor flags 1301a and 1301b are provided on the side of the tray 80 to block light from the light-emitting element of the tray detection sensor 1302 toward the light-receiving element. Note that the arrangement of the tray detection sensor 1302 and the sensor flags 1301a and 1301b shown in FIGS. 13 and 14 is merely an example.

[0159] As shown in Figures 13(A), 13(C), 14(A), and 14(C), the tray detection sensor 1302 is configured to output an ON signal when the light from the light-emitting element to the light-receiving element is blocked by the sensor flag 1301a or 1301b. Also, as shown in Figures 13(B) and 14(B), the tray detection sensor 1302 is configured to output an OFF signal when the light from the light-emitting element to the light-receiving element is not blocked by the sensor flag 1301a or 1301b.

[0160] In this way, the tray detection sensor 1302 of this example is configured to output an ON signal when the tray 80 is in the storage position or the removal position, and to output an OFF signal when the tray 80 is moving between the storage position and the removal position. The output of the tray detection sensor 1302 changes as the tray 80 moves. The direction of movement of the tray 80 is determined by the rotation direction of the motor M2. Therefore, the tray state (in the storage position, moving to the removal position, in the removal position, or moving to the storage position) can be determined based on the rotation direction of the motor M2 and the output of the tray detection sensor 1302.

[0161] 13(A) to 13(D) will be used to describe an example of detecting the tray state when the tray 80 is moved from the storage position to the removal position. When the tray 80, which is in the storage position as shown in FIG. 13(A), is moved from the storage position to the removal position, the engine control unit 102 (exchange control unit 1021) in FIG. 15 (described later) starts driving the motor M2 to rotate clockwise (forward) in FIG. 13(A). When the motor M2 starts rotating (forward), the tray 80 starts moving toward the removal position as shown in FIG. 13(B). This causes the output of the tray detection sensor 1302 to change from an ON signal to an OFF signal as shown in FIG. 13(D). Based on the change in the output of the tray detection sensor 1302, the engine control unit 102 determines that the tray 80 is moving from the storage position to the removal position.

[0162] Thereafter, while the motor M2 continues to rotate (forward), the output of the tray detection sensor 1302 changes from an OFF signal to an ON signal, as shown in Fig. 13(D). Based on the change in the output of the tray detection sensor 1302, the engine control unit 102 determines that the tray 80 has reached the removal position, and stops the motor M2.

[0163] 14(A) to 14(D), an example of detecting the tray state when the tray 80 is moved from the removal position to the storage position will be described. When the tray 80, which is in the removal position as shown in FIG. 14(A), is moved from the removal position to the storage position, the engine control unit 102 (exchange control unit 1021) starts driving the motor M2 to rotate counterclockwise (reverse) in FIG. 14(A). When the motor M2 starts rotating (reverse), the tray 80 starts moving toward the storage position as shown in FIG. 14(B). This causes the output of the tray detection sensor 1302 to change from an ON signal to an OFF signal as shown in FIG. 14(D). Based on the change in the output of the tray detection sensor 1302, the engine control unit 102 determines that the tray 80 is moving from the removal position to the storage position.

[0164] Thereafter, while the motor M2 continues to rotate (reversely), the output of the tray detection sensor 1302 changes from an OFF signal to an ON signal, as shown in Fig. 14(D). Based on the change in the output of the tray detection sensor 1302, the engine control unit 102 determines that the tray 80 has reached the storage position, and stops the motor M2.

[0165] The engine control unit 102 (exchange control unit 1021) stores tray information including the determination result of the tray status in the nonvolatile memory 105. The tray information stored in the nonvolatile memory 105 is retained even while the image forming apparatus 1 is in a power-off state. Therefore, even after the image forming apparatus 1 is started up from a power-off state to a power-on state, it is possible to grasp the status of the tray 80 based on the tray information stored in the nonvolatile memory 105.

[0166] <Cartridge replacement related configuration> Next, a configuration related to cartridge replacement in the image forming apparatus 1 will be described. FIG. 15(A) shows an example of the control configuration of the image forming apparatus 1. The controller 100 controls the entire image forming apparatus 1. For example, the controller 100 can be configured to communicate with a host computer (not shown) via a network. The host computer can be any information processing device with a communication function, such as a personal computer, tablet, or smartphone. When the controller 100 receives a print job from the host computer, it transmits image data of the image to be printed to the engine control unit 102, causing the engine control unit 102 to form an image based on the image data.

[0167] The operation unit 101 provides a user interface for the user to operate the image forming apparatus 1. As an example, the operation unit 101 may include a touch panel. By operating the touch panel, the user can specify one of the cartridges 70y, 70m, 70c, and 70k and instruct the controller 100 to replace the specified cartridge 70. The operation unit 101 may also include one or more buttons. In this case, for example, the operation unit 101 may include a button for specifying the cartridge to be replaced among the cartridges 70y, 70m, 70c, and 70k, and a button for instructing the controller 100 to replace the specified cartridge. Such buttons may be provided near the door 14 of the frame 16.

[0168] In this way, the controller 100 is configured to receive an instruction to replace the cartridge 70 through the operation unit 101. The controller 100 may further be configured to receive an instruction to replace the cartridge 70 from the host computer. When the controller 100 receives an instruction to replace the cartridge 70, it notifies the engine control unit 102 of the cartridge to be replaced and instructs the engine control unit 102 to replace the cartridge.

[0169] The engine control unit 102 controls the components described with reference to FIGS. 1 to 12 to control image formation on the sheet S. The engine control unit 102 has a CPU 103, which is a processor, a volatile memory 104, and a non-volatile memory 105. The CPU 103 controls image formation on the sheet S by executing a control program stored in the non-volatile memory 105. In this case, the CPU 103 stores temporary information in the volatile memory 104. The non-volatile memory 105 also stores various control data used by the CPU 103 for its control. The CPU 103 can include one or more processors. The engine control unit 102 may also employ a configuration that uses an application specific integrated circuit (ASIC) in addition to or instead of the CPU 103.

[0170] 15(A) shows only the components controlled by the engine control unit 102 that are necessary for explaining the embodiment, and other components are omitted. Specifically, FIG. 15(A) shows the scanner 4 that forms an electrostatic latent image on the photosensitive drum 2, and motors M1 and M2. Motor M1 is the drive source for the rotary body 90. Motor M2 is the drive source for the drive rack 15 (i.e., the drive source for moving the tray 80 between the storage position and the removal position).

[0171] In this embodiment, cartridges 70y, 70m, 70c, and 70k are provided with cartridge memories 72y, 72m, 72c, and 72k, which are non-volatile memory devices. In the following description, cartridge memories 72y, 72m, 72c, and 72k will be collectively referred to as cartridge memory 72. When a cartridge 70 is in the mounting position, the engine control unit 102 is configured to be able to access the cartridge memory 72 provided in that cartridge 70. The cartridge memory 72 stores, for example, an initial value T0 of the remaining amount of toner, the amount of toner supplied to the development unit 50 in one replenishment (hereinafter referred to as the replenishment amount T sup ), and information indicating the amount T of toner remaining in the cartridge 70 at the present time, etc. are stored.

[0172] The power supply control unit 106 controls the power supply to various members (devices) included in the image forming apparatus 1. The power supply control unit 106 may be configured with one or more processors or may be configured with an ASIC.

[0173] FIG. 15(B) shows an example of the functional configuration of the engine control unit 102. In this embodiment, each functional block shown in the figure is realized by the CPU 103 executing a control program. Note that at least some of the functional blocks shown in the figure may be realized by an ASIC. The engine control unit 102 has an image formation control unit 1020, an exchange control unit 1021, and a cartridge remaining amount obtaining unit 1022. Furthermore, if the engine control unit 102 is configured to also manage the amount of toner remaining in the development unit 50, it further has a unit remaining amount obtaining unit 1023.

[0174] The image formation control unit 1020 controls the operation of various components (e.g., the scanner 4, the developing unit 50, and the fixing device 40) related to the image formation operation, thereby controlling the image formation operation in the image forming apparatus 1. The image formation control unit 1020 causes an image to be formed on the sheet S based on image data received from the controller 100.

[0175] The exchange control unit 1021 controls processing related to the exchange of the cartridge 70. The exchange control unit 1021 controls the rotation of the rotary body 90 by controlling the motor M1, and controls the movement of the tray 80 by controlling the motor M2. The exchange control unit 1021 also determines (detects) the state of the tray 80 (state in the storage position, state in the process of moving to the removal position, state in the removal position, or state in the process of moving to the storage position) based on the output of the tray detection sensor 1302. The exchange control unit 1021 stores tray information including the determination result of the state of the tray 80 in the nonvolatile memory 105.

[0176] The cartridge remaining amount obtaining unit 1022 is configured to obtain and manage the remaining amount of toner T in each cartridge 70. In this embodiment, the cartridge remaining amount obtaining unit 1022 functions as an example of an obtaining unit that obtains the remaining amount of toner in a cartridge. When a single supply from a cartridge 70 to the developing unit 50 is performed, the cartridge remaining amount obtaining unit 1022 calculates the remaining amount of toner T in the cartridge 70 as the supply amount T supThe remaining toner amount T in the cartridge 70 at the current time is managed by updating the remaining toner amount T so that it decreases by T0. The initial value of the remaining toner amount T is T0. The cartridge remaining amount obtaining unit 1022 manages the remaining toner amount T in each cartridge 70 by storing it in the corresponding cartridge memory 72.

[0177] Here, "one replenishment" from the cartridge 70 to the developing unit 50 can be defined as follows. In the image forming apparatus 1 of this embodiment, toner is replenished from the cartridge 70 to the developing unit 50 during the period in which the rotary body 90 makes one rotation while the cartridge 70 is positioned above the developing unit 50. In this specification, "one replenishment" can be defined as replenishment by rotating the rotary body 90 once. Therefore, when the rotary body 90 makes n rotations (n ​​is an integer equal to or greater than 1), n ​​replenishments are performed. In this case, the replenishment amount T sup is the amount of toner remaining in the cartridge 70 that decreases when the rotary body 90 is rotated once.

[0178] The amount of toner replenished from the cartridge 70 to the developing unit 50 may vary depending on how the rotary body 90 is rotated. For example, while the rotary body 90 is developing an electrostatic latent image with toner of a certain color (first color), its rotation is stopped with the cartridge 70 containing the toner of the first color in the developing position. After the development of the first color is completed, the cartridge 70 containing the toner of the second color is rotated until it assumes the developing position for development of the next color (second color). In this way, the rotary body 90 is not rotated at a constant speed, but is rotated intermittently, and the amount of toner replenished from the cartridge 70 to the developing unit 50 may vary depending on the period during which it is rotated and the period during which it is not rotated. Furthermore, the amount of toner replenished to the developing unit 50 may also vary depending on the rotation speed of the rotary body 90. For this reason, in this embodiment, the replenishment amount T supcan be defined as the amount of toner supplied from the cartridge 70 to the developing unit 50 when the rotary body 90 is rotated once in a predetermined manner. Here, rotating the rotary body 90 once in a predetermined manner means rotating the rotary body 90 once in accordance with a predefined rotation speed, a predefined stop timing of the rotation drive, and a predefined stop period.

[0179] Furthermore, even when the cartridge 70 is positioned above the developing unit 50, the amount of toner replenished from the cartridge 70 to the developing unit 50 may vary depending on the relative position (orientation) of the cartridge 70 with respect to the developing unit 50. For example, the amount of toner replenished to the developing unit 50 when the developing unit 50 is in a predetermined position with respect to the cartridge 70 is assumed to be the maximum. If this maximum amount is significantly larger than the amount of toner replenished to the developing unit 50 when the developing unit 50 is in another position, this predetermined value can be defined as the "replenishment position." In this case, a "single replenishment" can also be defined as the replenishment when the cartridge 70 passes the replenishment position due to the rotation of the rotary body 90.

[0180] Note that, for example, if the engine control unit 102 is configured to electrically control the opening and closing of the receiving opening 53b of the developing unit 50 using a sealing member (not shown) that covers the receiving opening 53b, the engine control unit 102 can control the replenishment by controlling the receiving opening 53b. In other words, the engine control unit 102 can replenish toner to the developing unit 50 by controlling the sealing member to open the receiving opening 53b only while the cartridge 70 is positioned above the developing unit 50 and within a predetermined range of directions relative to the developing unit. In this case, "one replenishment" can also be defined as the replenishment performed from the time the engine control unit 102 opens the receiving opening 53b to the time it closes it.

[0181] The unit remaining amount acquiring unit 1023 is configured to acquire and manage the toner remaining amount D in the developing unit 50. The toner remaining amount D in the developing unit 50 is managed by the unit remaining amount acquiring unit 1023, for example, as follows: During image formation, the engine control unit 102 transmits a laser drive signal to the scanner 4 for driving the laser of the scanner 4. The laser drive signal is, for example, a pulse width modulation signal (PWM). While the laser drive signal is at a high level, the scanner 4 emits laser light to expose the photosensitive drum 2, and while the laser drive signal is at a low level, the scanner 4 does not emit laser light and therefore does not expose the photosensitive drum 2. Note that toner adheres to the area of ​​the photosensitive drum 2 exposed to the laser light, and toner does not adhere to the area of ​​the photosensitive drum 2 not exposed to the laser light. Therefore, the toner consumption amount C due to image formation can be determined by counting the number of high-level pulses of the laser drive signal during the period when laser light is emitted toward the photosensitive drum 2. In this way, the unit remaining amount obtaining unit 1023 determines the toner consumption amount C due to image formation.

[0182] When one supply from the cartridge 70 to the development unit 50 is performed, the unit remaining amount obtaining unit 1023 calculates the remaining toner amount D in the development unit 50 as a supply amount T sup The remaining amount of toner D in the developing unit 50 can be managed by increasing the remaining amount of toner D in the developing unit 50 by the toner consumption amount C each time an image is formed and decreasing the remaining amount of toner D in the developing unit 50 by the toner consumption amount C. The initial value of the remaining amount of toner D in the developing unit 50 is, for example, 0.

[0183] Furthermore, the unit remaining amount obtaining unit 1023 may be configured to manage the remaining toner amount D by measuring the remaining toner amount D in the developing unit 50. For example, the remaining toner amount D in the developing unit 50 can be estimated by measuring the capacitance between the supply roller 52 and the developing roller 51. The capacitance between the supply roller 52 and the developing roller 51 can be measured by applying an AC voltage to the supply roller 52 while the supply roller 52 and the developing roller 51 are spaced apart, and detecting the voltage induced in the developing roller 51. Alternatively, it is also possible to provide two electrodes specifically used for measuring the remaining toner amount D in the developing unit 50, and measure the remaining toner amount D in the developing unit 50 based on the capacitance between the two electrodes determined by applying a voltage to the two electrodes.

[0184] <Cartridge movement control> Next, the movement control of the cartridge 70 performed by the exchange control unit 1021 (CPU 102) of the engine control unit 102 in this embodiment will be described.

[0185] When the replacement control unit 1021 (CPU 102) receives a replacement instruction from the controller 100, it performs movement control to move the cartridge 70 to be replaced that is attached to the rotary body 90 to the retracted position. The replacement instruction is input by a user via, for example, the operation unit 101. In this embodiment, the replacement instruction is an example of a movement instruction for the cartridge 70 to move the cartridge 70 to the retracted position. When the replacement control unit 1021 receives a replacement instruction, it first performs a process of rotating the rotary body 90 so that the rotary body 90 assumes the replacement posture of the cartridge 70 to be replaced. The replacement control unit 1021 further performs a process of moving the tray 80, on which the cartridge 70 to be replaced is attached, from the storage position toward the removal position, thereby moving the cartridge 70 from the attachment position to the retracted position. After starting rotation of the motor M2, the replacement control unit 1021 stops the motor M2 when it detects that the tray 80 has reached the removal position based on the output of the tray detection sensor 1302.

[0186] In this way, the replacement control unit 1021 moves the cartridge 70 to the retracted position. This allows the user to remove the cartridge 70 from the tray 80 and install a new cartridge 70 (replacement work). The mounting position is the position of the target cartridge when the rotary body 90 is in the replacement position, and is also referred to as a first position inside the rotary body 90. The retracted position is also referred to as a second position outside the rotary body 90 where the cartridge 70 can be replaced. In this way, when a cartridge replacement command is received, the replacement control unit 1021 performs a movement process to move the cartridge 70 housed in the rotary body 90 from the mounting position (first position) inside the rotary body 90 to a retracted position (second position) outside the rotary body 90 where the cartridge 70 can be replaced.

[0187] After the replacement work is completed, for example, the user performs an operation to notify the completion of the replacement work through the operation unit 101. The controller 100 transmits a notification of the completion of the replacement work to the engine control unit 102 (replacement control unit 1021). Upon receiving the notification of the completion of the replacement work, the replacement control unit 1021 performs movement control to move the cartridge 70 from the retracted position to the mounted position. The replacement control unit 1021 performs processing to move the cartridge 70 from the retracted position to the mounted position by moving the tray 80 on which the replaced cartridge 70 is mounted from the ejection position toward the housing position. After starting the rotation of the motor M2, the replacement control unit 1021 stops the motor M2 when it detects that the tray 80 has reached the housing position based on the output of the tray detection sensor 1302.

[0188] In this way, the replacement control unit 1021 moves the cartridge 70 to the mounting position, thereby completing the replacement of the cartridge 70 based on the replacement instruction.

[0189] In this embodiment, when the replacement control unit 1021 detects that the cartridge 70 needs to be replaced based on the remaining toner amount T of the cartridge 70, it performs a movement process to move the cartridge 70 to the retracted position (second position) even if an instruction to replace the cartridge 70 has not been issued. As described above, the remaining toner amount T is detected (managed) by the cartridge remaining amount acquisition unit 1022. For example, when the remaining toner amount T of the cartridge 70 falls below a threshold (i.e., when it detects that the cartridge 70 needs to be replaced), the replacement control unit 1021 performs a movement process to move the cartridge 70 to the retracted position even if an instruction to replace the cartridge 70 has not been issued. This movement process can be performed in the same way as when an instruction to replace the cartridge 70 has been issued. Note that the threshold value for the remaining toner amount T may be set to 0, in which case it will be detected that the remaining toner amount T has reached 0.

[0190] In this way, when cartridge 70 moves to the retracted position, cartridge 70 and tray 80 protrude outside apparatus main body 1A through opening 16a, making it easier for the user to recognize the need to replace cartridge 70. Therefore, it is possible to shorten the downtime until image formation becomes possible after the user has completed the cartridge 70 replacement work, and it is possible to reduce the stress on the user caused by not being able to use image forming apparatus 1.

[0191] <Processing Procedure> 16 is a flowchart showing an example of a procedure for controlling the movement of the cartridge 70, which is executed by the image forming apparatus 1 according to this embodiment. The process according to this procedure is executed repeatedly (for example, periodically) while the image forming apparatus 1 is running.

[0192] In S101, the CPU 102 determines whether the cartridge 70 is in the retracted position based on the tray information stored in the nonvolatile memory 105. If the tray 80 is in the ejected position, it means that one of the cartridges 70 is in the retracted position. Therefore, if the tray information indicates that the tray 80 is in the ejected position, the CPU 102 determines that the cartridge 70 is in the retracted position and ends the processing of this procedure. On the other hand, if the tray information indicates that the tray 80 is in the housed position, the CPU 102 determines that the cartridge 70 is not in the retracted position (is in the mounted position), and proceeds to S102.

[0193] In S102, CPU 102 determines whether image forming operation is being performed. If image forming operation is being performed, CPU 102 terminates the process of this procedure. If image forming operation is not being performed, CPU 102 proceeds to S103. This allows the process from S103 onward to be performed on the condition that image forming apparatus 1 is in a state where it can perform the process of moving cartridge 70 to the retracted position. Note that if image forming apparatus 1 is not in a state where it can perform the process of moving cartridge 70 to the retracted position, for example, because it is performing a preparatory operation for image formation, CPU 102 may terminate the process of this procedure without proceeding to S103. In other words, CPU 102 may proceed from S102 to S103 when image forming apparatus 1 is in a state where it can perform the process of moving cartridge 70 to the retracted position.

[0194] In S103, the CPU 102 determines whether or not a replacement instruction for a cartridge 70 has been received. If the CPU 102 has received a replacement instruction for any of the cartridges 70, the process proceeds to S104. In S104, the CPU 102 performs a movement process to move the cartridge 70 to be replaced in accordance with the replacement instruction to the retracted position. The movement process includes a process of rotating the rotary body 90 to assume the replacement posture of the cartridge 70 to be replaced, and a process of moving the tray 80 on which the cartridge 70 to be replaced is attached from the storage position toward the removal position. By moving the tray 80 from the storage position to the removal position, it is possible to move the cartridge 70 from the attachment position to the retracted position. When the movement process for the cartridge 70 is completed, the CPU 102 ends the process of this procedure.

[0195] Furthermore, if the CPU 102 has not received an instruction to replace the cartridge 70, the process proceeds from S103 to S105. In S105, the CPU 102 determines whether any of the cartridges 70 attached to the rotary body 90 is empty (empty). The remaining toner amount T of each cartridge 70 is managed by the cartridge remaining amount acquisition unit 1022. Here, the empty (empty) state of a cartridge 70 indicates a state in which the toner required for image formation cannot be replenished from the cartridge 70 to the developing unit 50. For example, if the remaining toner amount T of the cartridge 70 is equal to or less than a threshold, the cartridge 70 is determined to be empty. This threshold is set, for example, as the amount of remaining toner at which the toner required for image formation cannot be replenished from the cartridge 70 to the developing unit 50. Note that the empty state can include a state in which the remaining toner amount of the cartridge 70 is zero.

[0196] If the CPU 102 determines that there is no cartridge with no toner remaining, it ends the processing of this procedure. On the other hand, if the CPU 102 determines that there is a cartridge with no toner remaining, it advances the processing from S105 to S106.

[0197] Here, even if a cartridge 70 is out of toner, image formation may be possible if toner remains in the corresponding development unit 50. Therefore, as a modification of the processing according to this procedure, the CPU 102 may perform, for example, the following processing. Specifically, when the CPU 102 determines that a cartridge with no toner remains exists, the CPU 102 may proceed from S105 to S106 on the condition that the development unit 50 is out of toner (empty) (the remaining toner amount T is equal to or less than a threshold). The remaining toner amount T in the development unit 50 is managed by the unit remaining amount acquisition unit 1023. The threshold used to determine the remaining toner amount T in the cartridge 70 may be referred to as a first threshold, and the threshold used to determine the remaining toner amount T in the development unit 50 may be referred to as a second threshold.

[0198] In S106, the CPU 102 performs a movement process to move the cartridge 70 with no remaining toner to the retracted position. As described above, this movement process includes a process of rotating the rotary body 90 to position the cartridge 70 to be processed in the replacement posture, and a process of moving the tray 80 on which the cartridge 70 to be processed is mounted from the storage position toward the removal position. Note that, if multiple cartridges 70 are to be moved, the CPU 102 performs a movement process to the retracted position for one of the cartridges.

[0199] When the movement process of cartridge 70 is completed, CPU 102 ends the process of this procedure. Note that if it is not desirable to continue to hold cartridge 70 at the retracted position after it has been moved to the retracted position, CPU 102 may perform a process of returning cartridge 70 to the mounted position (moving cartridge 70 from the retracted position to the mounted position) after a predetermined time has elapsed since moving cartridge 70 to the retracted position.

[0200] As described above, the image forming apparatus 1 of this embodiment includes a rotatable rotary body 90 (rotary), which includes a developing unit 50 that develops an electrostatic latent image formed on a photosensitive drum 2 (photosensitive member) with toner supplied from the cartridge 70. The moving device 85 is configured to move the cartridge 70 between an installed position where the cartridge 70 is located inside the rotary body 90 and a retracted position where the cartridge 70 is located outside the rotary body 90. The cartridge remaining amount acquiring unit 1022 acquires the remaining toner amount T in the cartridge 70. When a movement instruction (replacement instruction) for the cartridge 70 is received, the replacement control unit 1021 (engine control unit 102) performs a movement process to control the moving device 85 to move the cartridge 70 from the installed position to the retracted position. If the acquired result of the cartridge remaining amount acquiring unit 1022 satisfies a predetermined condition, the replacement control unit 1021 further performs the movement process for the cartridge 70 even if a movement instruction for the cartridge 70 has not been received. For example, when the remaining toner amount T acquired by the cartridge remaining amount acquisition unit 1022 falls below a threshold, the replacement control unit 1021 performs the movement process of the cartridge 70 even if an instruction to move the cartridge 70 has not been received.

[0201] In this manner, in this embodiment, even if the user has not instructed to replace the cartridge 70, a process is performed to move the cartridge 70 whose remaining toner amount T meets a predetermined condition (for example, a cartridge 70 with no remaining toner) to the retracted position. This makes it easier for the user to recognize the need to replace the cartridge 70. This makes it possible to shorten the downtime until the user has completed the cartridge 70 replacement work and image formation becomes possible, and reduces the stress on the user caused by not being able to use the image forming apparatus 1.

[0202] <Modification> The replacement control unit 1021 may be configured to perform processing to move the tray 80 from the storage position to the removal position (moving the cartridge 70 from the storage position to the retracted position) on the condition that it has detected a state in which image formation cannot be performed, not limited to when the cartridge 70 is out of toner. This makes it easier for the user to recognize that image formation cannot be performed by the image forming apparatus 1.

[0203] For example, when the replacement control unit 1021 detects that the cartridge 70 is not installed (not installed) in the image forming apparatus 1 (rotary body 90), it may perform processing to move the tray 80 corresponding to the not-installed cartridge 70 from the storage position (position corresponding to the installed position) to the removal position (position corresponding to the retracted position) even if it has not received an instruction to move the cartridge 70 (no instruction to replace the cartridge 70 has been received). This allows the user to immediately recognize that the image forming apparatus 1 cannot perform image formation due to the cartridge 70 not being installed.

[0204] In the above example, a sensor for detecting that the cartridge 70 is not yet installed in the image forming apparatus 1 (rotary body 90) may be provided in the image forming apparatus 1. In this case, the CPU 102 detects that the cartridge 70 is not yet installed in the image forming apparatus 1 (rotary body 90) based on the output of the sensor. Alternatively, the CPU 102 may detect that the cartridge 70 is not yet installed in the image forming apparatus 1 (rotary body 90) based on the inability to acquire information from the cartridge memory 72 of the cartridge 70.

[0205] [Second embodiment] The image forming apparatus 1 of the first embodiment is configured to perform a process of moving the cartridge 70 that has no remaining toner to the retracted position even when the user has not instructed to replace the cartridge 70. In this case, if the cartridge 70 continues to be held in the retracted position (if the tray 80 continues to be held in the removal position), dust and other contaminants may enter the apparatus through the opening 16a, causing a malfunction in the operation of the image forming apparatus 1.

[0206] In the second embodiment, the image forming apparatus 1 is configured to keep the cartridge 70 with no toner remaining in the installation position until an image formation instruction is received, thereby preventing such a problem from occurring. Also, by configuring the image forming apparatus 1 to move the cartridge 70 to the retracted position at the timing when an image formation instruction is received, it becomes possible to make it easier for the user to recognize the need to replace the cartridge 70, as in the first embodiment. The following will mainly describe the differences from the first embodiment.

[0207] 17 is a flowchart showing an example of a procedure for controlling the movement of the cartridge 70, which is executed by the image forming apparatus 1 according to this embodiment. The process according to this procedure is executed repeatedly (for example, periodically) during startup of the image forming apparatus 1. The procedure in FIG. 17 differs from the procedure in FIG. 16 in the first embodiment in that S201 is added between S105 and S106.

[0208] In this embodiment, if the CPU 102 determines in S105 that a cartridge with no toner remaining exists, the CPU 102 proceeds to S201. Note that, as described above, if the CPU 102 determines that a cartridge with no toner remaining exists, the CPU 102 may proceed to S201 on the condition that the development unit 50 is in an empty state with no toner remaining (the remaining toner amount T is equal to or less than a threshold value).

[0209] In S201, the CPU 102 determines whether or not an image formation instruction (print instruction) has been received from the controller 100. If the CPU 102 has not received an image formation instruction from the controller 100, the CPU 102 ends the processing of this procedure. On the other hand, if the CPU 102 has received an image formation instruction from the controller 100, the CPU 102 advances the processing to S106.

[0210] In S106, the CPU 102 performs a movement process to move the cartridge 70 with no remaining toner to the retracted position, as in the first embodiment. When the movement process of the cartridge 70 is completed, the CPU 102 ends the process of this procedure. Note that if it is not desirable to continue to hold the cartridge 70 in the retracted position after it has been moved to the retracted position, the CPU 102 may perform a process to return the cartridge 70 to the mounted position after a predetermined time has elapsed since the cartridge 70 moved to the retracted position.

[0211] As described above, in the image forming apparatus 1 of this embodiment, when the remaining toner amount T acquired by the cartridge remaining amount acquisition unit 1022 falls below a threshold, the replacement control unit 1021 performs the movement process for the cartridge 70 in response to the reception of an image formation instruction (moves the cartridge 70, which is out of toner, to the retracted position), even if the replacement control unit 1021 has not received a movement instruction (replacement instruction) for the cartridge 70. That is, by continuing to hold the cartridge 70 in the retracted position, the replacement control unit 1021 can reduce the possibility of dust or other contaminants entering the apparatus through the opening 16a, while making it easier for the user to recognize the need to replace the cartridge 70. This shortens the downtime until the user has completed the cartridge 70 replacement operation and image formation becomes possible, thereby reducing the stress on the user caused by not being able to use the image forming apparatus 1.

[0212] As in the modified example of the first embodiment, when it is detected that the cartridge 70 is not installed in the image forming device 1 (rotary body 90), a process may be performed to move the tray 80 in which the cartridge 70 is not installed from the storage position to the removal position.

[0213] [Third embodiment] In the third embodiment, the image forming apparatus 1 is configured to control the movement of the cartridge 70 from the retracted position to the mounted position (moving the tray 80 from the ejected position to the housed position) when transitioning to the sleep mode. This prevents dust and other contaminants from entering the apparatus through the opening 16a by continuing to hold the cartridge 70 in the retracted position (holding the tray 80 in the ejected position) while in the sleep mode. Furthermore, if the cartridge 70 is moved to the retracted position in accordance with a cartridge 70 movement instruction (replacement instruction) and then moved to the mounted position when transitioning to the sleep mode, the image forming apparatus 1 is configured to move the cartridge 70 back to the retracted position when waking up from the sleep mode. This allows the user to immediately replace the cartridge 70 after waking up from the sleep mode. The following mainly describes the differences from the first embodiment.

[0214] The image forming apparatus 1 of this embodiment has a low power consumption mode (sleep mode) as an operating mode. In the sleep mode, the image forming apparatus 1 transitions to a sleep state by stopping the supply of power to devices used in the image forming operation (for example, actuators such as motors, and sensors). In the sleep state, the power consumption of the image forming apparatus 1 is reduced more than in the normal mode (non-sleep mode). The image forming apparatus 1 operating in the normal mode transitions from the normal mode to the sleep mode, for example, when a predetermined time has passed without any operation being performed on the operation unit 101 in a standby state in which no image forming operation is being performed.

[0215] In the image forming apparatus 1 of this embodiment, the power supply control unit 106 controls the transition to and recovery from a sleep mode (sleep state) by controlling the power supply to each device in the image forming apparatus 1. In the sleep state, the power supply to the CPU 103, the volatile memory 104, and the nonvolatile memory 105 is stopped, thereby stopping the operation of these devices.

[0216] <Sleep transition control> Fig. 18A is a flowchart showing an example of a procedure for sleep transition control in the image forming apparatus 1 of this embodiment. The process according to the procedure in Fig. 18A is executed while the image forming apparatus 1 is in a standby state.

[0217] In S301, the CPU 103 determines whether or not a sleep transition instruction has been received from the controller 100 in the standby state, and proceeds to S302 in response to the reception of the sleep transition instruction. After receiving the sleep transition instruction, in S302 the CPU 103 determines whether or not the tray 80 is in the storage position based on the tray information stored in the nonvolatile memory 105. If the CPU 103 determines that the tray 80 is not in the storage position (is in the removal position), the CPU 103 proceeds to S303, and if the CPU 103 determines that the tray 80 is in the storage position, the CPU 103 proceeds to S304.

[0218] In S303, the CPU 103 (exchange control unit 1021) performs a movement process to move the tray 80 from the ejection position to the storage position. At this time, the CPU 103 stores information indicating that the tray 80 was in the ejection position (the cartridge 70 was in the retracted position) before the transition to the sleep state in the tray information in the nonvolatile memory 105. When the movement process of the tray 80 to the storage position is completed, the CPU 103 advances the process to S304.

[0219] In this embodiment, the CPU 102 stores information indicating whether or not the tray 80 at the removal position has been moved to the removal position (the cartridge 70 has been moved to the retracted position) in accordance with a replacement instruction, in the nonvolatile memory 105. This information is stored in the nonvolatile memory 105 together with the tray information in response to a replacement instruction for the cartridge 70 being input to the operation unit 101 by the user.

[0220] In S304, the CPU 103 instructs the power supply control unit 106 to transition to sleep mode. In accordance with the instruction from the CPU 103, the power supply control unit 106 controls the power supply to each device in the image forming apparatus 1, thereby transitioning the image forming apparatus 1 to sleep mode. When the transition to sleep mode is complete, the power supply control unit 106 ends the processing of this procedure.

[0221] In this way, when image forming apparatus 1 transitions to the sleep state, it operates to move tray 80 from the removal position to the storage position before transitioning to the sleep state. This prevents malfunctions in the operation of image forming apparatus 1 caused by dirt such as dust entering the apparatus through opening 16a while image forming apparatus 1 is in the sleep state.

[0222] <Sleep wake-up control> Fig. 18B is a flowchart showing an example of a procedure for controlling recovery from sleep in the image forming apparatus 1 of this embodiment. The process according to the procedure in Fig. 18B is executed while the image forming apparatus 1 is in a sleep state.

[0223] In S311, the power supply control unit 106 determines whether or not a return from sleep instruction has been received from the controller 100, and proceeds to S312 in response to the reception of the return from sleep instruction. After receiving the return from sleep instruction, in S312 the power supply control unit 1427 controls the power supply to each device in the image forming apparatus 1, thereby causing the image forming apparatus 1 to return from sleep mode (sleep state).

[0224] Thereafter, in S313, CPU 102 determines whether to execute a movement process to move tray 80 from the storage position to the removal position based on the tray information stored in nonvolatile memory 105. Specifically, CPU 102 determines to execute a movement process if the tray information includes information indicating that tray 80 was in the removal position before transitioning to the sleep state and that movement of tray 80 to the removal position was performed in accordance with a replacement instruction. In response to this determination, CPU 102 proceeds to S314. On the other hand, if the tray information stored in nonvolatile memory 105 does not include such information, CPU 102 determines not to execute a movement process and ends the processing of this procedure.

[0225] In S314, the CPU 102 performs a movement process to move the tray 80 from the storage position to the removal position. When the movement process of the tray 80 to the removal position is completed, the process of this procedure ends.

[0226] As described above, when the image forming apparatus 1 of this embodiment returns from the sleep mode to the tray 80, if the tray 80 was in the removal position based on a movement instruction (replacement instruction) for the cartridge 70 before the image forming apparatus 1 transitioned to the sleep mode, the image forming apparatus 1 returns the tray 80 from the storage position to the removal position. This allows the user to immediately replace the cartridge 70 after the image forming apparatus 1 returns from the sleep mode.

[0227] Although the image forming apparatus 1 of this embodiment performs a movement process to move the tray 80 from the ejection position to the storage position (moving the cartridge 70 from the retracted position to the mounted position) when transitioning to the sleep state, a similar process may be performed, for example, when transitioning to the power-off state. Furthermore, if the tray 80 was in the ejection position based on a movement instruction (replacement instruction) for the cartridge 70 before transitioning to the power-off state, the image forming apparatus 1 may operate to return the tray 80 from the storage position to the ejection position when returning from the power-off state.

[0228] Furthermore, the image forming apparatus 1 of this embodiment may operate to return the tray 80 from the storage position to the ejection position when returning from the sleep mode, regardless of whether or not there was a movement instruction (replacement instruction) for the cartridge 70 before transitioning to the sleep mode. That is, when the tray information indicates that the tray 80 was in the ejection position (the cartridge 70 was in the retracted position) before transitioning to the sleep mode, the image forming apparatus 1 determines to execute the movement process (S313) and performs the movement process to move the tray 80 from the storage position to the ejection position (S314). In this way, by moving the tray 80 to the ejection position (moving the cartridge 70 to the retracted position) after returning to the sleep mode, the user can more easily recognize the need to replace the cartridge 70 when using the image forming apparatus 1.

[0229] [Other embodiments] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0230] The disclosure of the present specification includes the following configurations. (Item 1) An image forming apparatus in which a cartridge containing toner can be detachably attached, A photoreceptor; a developing unit for developing an electrostatic latent image formed on the photosensitive member with the toner supplied from the cartridge, the developing unit being rotatable; a moving device that moves the cartridge between a mounting position where the cartridge is located inside the rotary and a retracted position where the cartridge is located outside the rotary; a control unit that, when receiving a command to move the cartridge, performs a movement process to control the moving device so as to move the cartridge from the mounting position to the retracted position; an acquisition unit that acquires the amount of toner remaining in the cartridge; Equipped with the control means performs the movement process when the acquisition result of the acquisition unit satisfies a predetermined condition, even if the movement instruction has not been received. An image forming apparatus characterized by: (Item 2) When the remaining amount of toner acquired by the acquisition unit becomes equal to or less than a threshold, the control unit performs the movement process even if the movement instruction has not been received. 2. The image forming apparatus according to item 1, (Item 3) when the remaining amount of toner acquired by the acquisition unit becomes equal to or less than a threshold, the control unit performs the movement process in response to reception of an image formation instruction even if the movement instruction has not been received. 2. The image forming apparatus according to item 1, (Item 4) the threshold value is defined as a remaining amount of toner that is not enough to replenish the toner required for image formation from the cartridge to the developing unit; 4. The image forming apparatus according to item 2 or 3. (Item 5) the developing unit has a container that contains the toner supplied from the cartridge, when the remaining amount of toner in the cartridge becomes equal to or less than a first threshold value and the remaining amount of toner in the container becomes equal to or less than a second threshold value, the control unit performs the movement process even if the movement instruction has not been received. 5. The image forming apparatus according to any one of items 1 to 4, (Item 6) the control means controls the moving device to move the cartridge from the retracted position to the mounted position after a predetermined time has elapsed since the cartridge was moved to the retracted position by the moving process. 6. The image forming apparatus according to any one of items 1 to 5, (Item 7) the moving device is attached to the rotary, the cartridge is removably mounted on a support member, and the support member supports the cartridge; the support member is movable relative to the rotary so that the cartridge moves between the mounting position and the retracted position; when the control unit detects that the cartridge is not installed in the image forming apparatus, the control unit moves the support member from the position corresponding to the retracted position to the position corresponding to the installed position even if the control unit has not received the movement instruction. 7. The image forming apparatus according to any one of items 1 to 6, (Item 8) When the image forming apparatus is to be put into a sleep state while the cartridge is in the retracted position, the control unit moves the cartridge from the retracted position to the mounted position before the image forming apparatus is put into the sleep state. 8. The image forming apparatus according to any one of items 1 to 7, wherein: (Item 9) When the cartridge is in the retracted position before the image forming apparatus is switched to the sleep state, the control unit moves the cartridge from the mounted position to the retracted position after the image forming apparatus is restored from the sleep state. 9. The image forming apparatus according to item 8, (Item 10) the moving process includes a process of rotating the rotary when the cartridge is not at the mounting position until the cartridge is at the mounting position, and a process of moving the cartridge from the mounting position to the retracted position. 10. The image forming apparatus according to any one of items 1 to 9, (Item 11) the moving process includes a process of moving the cartridge from the mounting position to the retracted position through an opening provided in a main body frame of the image forming apparatus, and the cartridge can be replaced in the retracted position. 11. The image forming apparatus according to any one of items 1 to 10, (Item 12) a direction from the mounting position toward the retracted position being parallel to a radial direction of the rotary from the center of the rotation axis of the rotary toward the opening; Item 12. The image forming apparatus according to item 11. (Item 13) the cartridge includes a memory device for storing information indicating the amount of toner replenished from the cartridge to the developing unit at one time; the obtaining unit determines the remaining amount of toner in the cartridge based on the replenishment amount; 13. The image forming apparatus according to any one of items 1 to 12, (Item 14) the cartridge attached to the image forming apparatus is accommodated in the rotary at a position adjacent to the developing unit, When the cartridge is housed in the rotary, an opening provided in the cartridge and an opening provided in the developing unit face each other, the amount of toner supplied from the cartridge to the developing unit at one time is the amount of toner supplied from the cartridge to the developing unit during one rotation of the rotary; Item 14. The image forming apparatus according to item 13,

[0231] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0232] 2: photosensitive drum, 50: developing unit, 85: moving device, 102: engine control unit, 70: toner cartridge (cartridge), 80: tray, 90: rotary body

Claims

1. An image forming apparatus in which a cartridge containing toner can be detachably attached, A photoreceptor; a developing unit for developing an electrostatic latent image formed on the photosensitive member with the toner supplied from the cartridge, the developing unit being rotatable; a moving device that moves the cartridge between a mounting position where the cartridge is located inside the rotary and a retracted position where the cartridge is located outside the rotary; a control unit that, when receiving a command to move the cartridge, performs a movement process to control the moving device so as to move the cartridge from the mounting position to the retracted position; an acquisition unit that acquires the amount of toner remaining in the cartridge; Equipped with the control means performs the movement process when the acquisition result of the acquisition unit satisfies a predetermined condition, even if the movement instruction has not been received. An image forming apparatus characterized by:

2. When the remaining amount of toner acquired by the acquisition unit becomes equal to or less than a threshold, the control unit performs the movement process even if the movement instruction has not been received.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. when the remaining amount of toner acquired by the acquisition unit becomes equal to or less than a threshold, the control unit performs the movement process in response to reception of an image formation instruction even if the movement instruction has not been received.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. the threshold value is defined as a remaining amount of toner that is not enough to replenish the toner required for image formation from the cartridge to the developing unit; 3. The image forming apparatus according to claim 2, wherein the image forming apparatus is a recording medium.

5. the developing unit has a container that contains the toner supplied from the cartridge, the control means performs the movement process when the remaining amount of toner in the cartridge becomes equal to or less than a first threshold value and the remaining amount of toner in the container becomes equal to or less than a second threshold value even if the movement instruction has not been received.

5. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

6. the control means controls the moving device to move the cartridge from the retracted position to the mounted position after a predetermined time has elapsed since the cartridge was moved to the retracted position by the moving process.

5. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

7. the moving device is attached to the rotary, the cartridge is removably mounted on a support member, and the support member supports the cartridge; the support member is movable relative to the rotary so that the cartridge moves between the mounting position and the retracted position; when the control unit detects that the cartridge is not installed in the image forming apparatus, the control unit moves the support member from the position corresponding to the retracted position to the position corresponding to the installed position even if the control unit has not received the movement instruction.

5. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

8. When the image forming apparatus is to be put into a sleep state while the cartridge is in the retracted position, the control unit moves the cartridge from the retracted position to the mounted position before the image forming apparatus is put into the sleep state.

5. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. When the cartridge is in the retracted position before the image forming apparatus is switched to the sleep state, the control unit moves the cartridge from the mounted position to the retracted position after the image forming apparatus is restored from the sleep state.

9. The image forming apparatus according to claim 8,

10. the moving process includes a process of rotating the rotary when the cartridge is not at the mounting position until the cartridge is at the mounting position, and a process of moving the cartridge from the mounting position to the retracted position.

5. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

11. the moving process includes a process of moving the cartridge from the mounting position to the retracted position through an opening provided in a main body frame of the image forming apparatus, and the cartridge can be replaced in the retracted position.

5. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

12. a direction from the mounting position toward the retracted position being parallel to a radial direction of the rotary from the center of the rotation axis of the rotary toward the opening; 12. The image forming apparatus according to claim 11.

13. the cartridge includes a memory device for storing information indicating the amount of toner replenished from the cartridge to the developing unit at one time; the obtaining unit determines the remaining amount of toner in the cartridge based on the replenishment amount; 5. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

14. the cartridge attached to the image forming apparatus is accommodated in the rotary at a position adjacent to the developing unit, When the cartridge is housed in the rotary, an opening provided in the cartridge and an opening provided in the developing unit face each other, the amount of toner supplied from the cartridge to the developing unit at one time is the amount of toner supplied from the cartridge to the developing unit during one rotation of the rotary; 14. The image forming apparatus according to claim 13.

Images