Image forming apparatus

Abstract

To further advance a conventional technique.SOLUTION: An image forming apparatus includes: an apparatus main body having an opening; a first unit attached to the apparatus main body so as to be drawn out from the apparatus main body through the opening; a second unit attached to the apparatus main body so as to be drawn out from the apparatus main body through the opening, the second unit having an engaged portion, and being configured to be drawn out from the apparatus main body together with the first unit, and also to be drawn out from the apparatus main body independently from the first unit; an engaging member 90 engaged with the engaged portion in a case where the second unit is drawn out from the apparatus main body, the engaging member having a first path 93B and a second path 92 branching from the first path 93B. In a case where the second unit is drawn out together with the first unit, the engaged portion passes the first path 93B, and in a case where the second unit is drawn out independently from the first unit, the engaged portion passes the second path 92.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art A known configuration of an image forming apparatus, such as a printer, copier, or multifunction device, includes a tray that is configured to be movable between the inside and outside of the main body of the image forming apparatus, and a cartridge that is removably attached to the tray.

[0003] For example, Patent Document 1 discloses an image forming apparatus that includes a tray on which a cartridge is removably mounted and that is configured to be able to be pulled out from both one end and the other end of the image forming apparatus.

[0004] Furthermore, for example, Patent Document 2 discloses an image forming apparatus including a tray to which a cartridge is removably attached, a transfer unit, and a fixing device provided at one end of the image forming apparatus. In the above configuration, the tray is configured to be removable from one end of the image forming apparatus, and the transfer unit is configured to be removable from the other end of the image forming apparatus. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-244018 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-206897 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention is a further development of conventional technology. [Means for solving the problem]

[0007] In order to achieve the above object, an image forming apparatus according to the present invention comprises: a device body having an opening; a first unit attached to the device body so as to be removable from the device body through the opening; a second unit attached to the device body so as to be removable from the device body through the opening, the second unit having an engaged portion and configured so as to be removable from the device body together with the first unit and so as to be removable from the device body independently of the first unit; an engaging member that engages with the engaged portion when the second unit is pulled out from the device main body, the engaging member having a first passage and a second passage branched from the first passage; Equipped with When the second unit is pulled out together with the first unit, the engaged portion passes through the first passage, and when the second unit is pulled out independently from the first unit, the engaged portion passes through the second passage. It is characterized by: [Effects of the Invention]

[0008] The present invention allows further development of conventional techniques. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating the overall configuration of a printer according to a first embodiment. [Figure 2] FIG. 1 is a diagram illustrating a printer according to a first embodiment with a door open. [Figure 3] FIG. 2 is a diagram illustrating the printer according to the first embodiment in a state where the fixing device is in a retracted position. [Figure 4] FIG. 2 is a diagram showing the printer of the first embodiment with two units pulled out. [Figure 5] FIG. 2 is a diagram showing the printer of the first embodiment in a state where only the transfer unit is pulled out. [Figure 6] 4A to 4C are diagrams illustrating the movement of a transfer unit and a tray unit according to the first embodiment. [Figure 7] 4A to 4C are diagrams illustrating the movement of a transfer unit and a tray unit according to the first embodiment. [Figure 8] FIG. 2 is a perspective view illustrating an engagement configuration of two units according to the first embodiment. [Figure 9] FIG. 4 is a side view illustrating the engagement structure of two units in the first embodiment. [Figure 10] FIG. 2 is a perspective view illustrating an engagement configuration of two units according to the first embodiment. [Figure 11] 3A and 3B are diagrams illustrating details of a main guide according to the first embodiment. [Figure 12] FIG. 3 is a diagram illustrating a movement path of a transfer unit according to the first embodiment. [Figure 13] FIG. 3 is a diagram illustrating a movement path of a transfer unit according to the first embodiment. [Figure 14] FIG. 3 is a diagram illustrating a movement path of a transfer unit according to the first embodiment. [Figure 15] FIG. 2 is a perspective view illustrating a restricting structure according to the first embodiment. [Figure 16] FIG. 2 is a diagram illustrating a regulation structure according to the first embodiment. [Figure 17] FIG. 2 is a diagram illustrating a regulation structure according to the first embodiment. [Figure 18] FIG. 10 is an explanatory diagram of a tray unit according to a modified example. [Figure 19] FIG. 10 is a diagram illustrating the overall configuration of a printer according to a second embodiment. [Figure 20] FIG. 10 is a diagram showing a printer according to a second embodiment in a state where a transfer unit is pulled out. [Figure 21] FIG. 10 is a diagram showing a printer according to a second embodiment with two units pulled out. [Figure 22] FIG. 10 is a diagram illustrating the overall configuration of a printer according to a third embodiment. [Figure 23] FIG. 10 is a diagram showing a printer according to a third embodiment in a state where a transfer unit is pulled out. [Figure 24] FIG. 10 is a diagram showing a printer according to a third embodiment with two units pulled out. [Figure 25] 10A and 10B are diagrams illustrating details of a main guide according to a third embodiment. [Figure 26] FIG. 10 is a diagram illustrating a movement path of a transfer unit according to a third embodiment. [Figure 27] FIG. 10 is a diagram illustrating a movement path of a transfer unit according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes in detail exemplary embodiments of the present invention with reference to the drawings. The dimensions, materials, shapes, and relative positions of the components described in the embodiments may be changed as appropriate depending on the configuration and various conditions of the device to which the invention is applied. In other words, the scope of the present invention is not limited to the following embodiments.

[0011] Example 1 [Configuration of image forming device] First, an image forming apparatus according to the present invention will be described. Generally, an image forming apparatus is an apparatus that forms an image on a recording medium using various known image formation principles and methods, such as an electrophotographic process, an electrostatic recording process, or a magnetic recording process. Examples of such an apparatus include copiers, printers (e.g., laser printers, LED printers, etc.), facsimile machines, word processors, and image display devices (electronic blackboards and electronic whiteboards). Recording media are those on which an image is formed by an image forming apparatus, and include, for example, paper, overhead projectors, and image displays.

[0012] A printer 1 as an image forming apparatus according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view showing the overall configuration of the printer 1. The printer 1 is an electrophotographic color laser beam printer that forms an image on a sheet S as a recording material.

[0013] The printer 1 includes a device main body (housing) 1A, a scanner (exposure device) 2, a control unit 3, and a door (opening / closing member) 20 that can be opened and closed relative to the device main body 1A. The printer 1 also includes a sheet feeding unit 30, a transfer unit (transfer device) 40, a tray unit (moving unit, support unit) 50, and a fixing device 80. The part including the device main body 1A and the door 20 is referred to as a main frame 100. The main frame 100 includes the exterior of the printer 1.

[0014] In the following description, the front side (front face side) of the printer 1 is the side where the door 20 is located. The rear side (rear face side) is the side opposite the front side (front face side). The front-to-rear direction is the direction from the rear side of the printer 1 to the front side (front direction) and the opposite direction (rear direction). The left and right sides are left and right when viewing the printer 1 from the front side. The left-to-right direction is the direction from right to left (left direction) and the opposite direction (right direction). The top and bottom sides are up and down in the direction of gravity (vertical direction). The top side is the direction from bottom to top, and the bottom side is the direction from top to bottom. Figure 1 is a diagram of the printer 1 viewed left and right, with the front-to-back direction indicated as H and the up-down direction indicated as V.

[0015] The device main body 1A houses the scanner 2, the control unit 3, the sheet feeding unit 30, the tray unit 50 as a first unit, the transfer unit 40 as a second unit, and the fixing device 80. The tray unit 50 and the transfer unit 40 are attached to the device main body 1A so that they can be pulled out from the device main body 1A.

[0016] The sheet feeding section 30 is a feeding section that has a stacking tray 31 on which sheets S as recording materials are stacked, and a supply roller 32. The stacking tray 31 is a paper feed cassette that is configured to be insertable into and removable from the device main body 1A in the front-rear direction. A user of the printer 1 can pull the stacking tray 31 out from the device main body 1A to the front side to replenish the sheets S. In other words, the user can insert and remove the stacking tray 31 and open and close the door 20 from the front side of the device main body 1A.

[0017] The tray unit 50 has cartridges PY, PM, PC, and PK, and a tray 51 that detachably holds each cartridge. The tray 51 has a tray handle 52. The tray handle 52 is provided at the front end of the tray 51, and a user can grasp the tray handle 52 to pull out the tray unit 50 from the apparatus main body 1A. The cartridges PY, PM, PC, and PK are each detachably attached to the tray 51. That is, the tray unit 50 has a plurality of cartridges P and the tray 51 to which the plurality of cartridges P are detachably attached.

[0018] Each of the cartridges PY, PM, PC, and PK can be attached to and detached from the tray 51 independently of the others. Cartridge PY contains yellow (Y), cartridge PM contains magenta (M), cartridge PC contains cyan (C), and cartridge PK contains black (K) toner (developer). Cartridges PY, PM, PC, and PK have the same configuration except for the toner colors they contain. Therefore, in the following explanation, the configuration and operation of only one of cartridges PY, PM, PC, and PK will be explained, and explanations of the others may be omitted. Furthermore, when there is no need to distinguish between cartridges PY, PM, PC, and PK, cartridges PY, PM, PC, and PK may be simply referred to as cartridge P.

[0019] In the first embodiment, the tray unit 50 includes a plurality of photosensitive drums (image carriers) 61, a plurality of The tray unit 50 is an image forming unit having a charging roller 62 (charging member) and multiple developing rollers (developer carriers) 71. Specifically, the tray unit 50 has four photosensitive drums 61, four charging rollers 62, and four developing rollers 63. The rotational axis directions of the photosensitive drums 61, the developing rollers 63, and the charging rollers 62 are parallel to the left-right direction of the printer 1.

[0020] The portion where a black (K) image is formed is called the black station (first station), the photosensitive drum 61 of the first station is called the first photosensitive drum, the developing roller 63 is called the first developing roller, and the charging roller 62 is called the first charging roller.

[0021] The portion where a cyan (C) image is formed is called a cyan station (second station), the photosensitive drum 61 of the second station is called a second photosensitive drum, the developing roller 63 is called a second developing roller, and the charging roller 62 is called a second charging roller.

[0022] The portion where a magenta (M) image is formed is called the magenta station (third station), the photosensitive drum 61 of the third station is called the third photosensitive drum, the developing roller 63 is called the third developing roller, and the charging roller 62 is called the third charging roller.

[0023] The portion where a yellow (Y) image is formed is called the yellow station (fourth station), the photosensitive drum 61 of the fourth station is called the fourth photosensitive drum, the developing roller 63 is called the fourth developing roller, and the charging roller 62 is called the fourth charging roller.

[0024] The cartridge PK is installed in the black station, the cartridge PC in the cyan station, the cartridge PM in the magenta station, and the cartridge PY in the yellow station. In the first embodiment, the cartridge PK is called the first cartridge, the cartridge PC is called the second cartridge, the cartridge PM is called the third cartridge, and the cartridge PY is called the fourth cartridge. The numbers 1, 2, 3, and 4 are used for convenience of explanation.

[0025] In the first embodiment, the cartridge P has a photosensitive drum 61, a charging roller 62, and a developing roller 63. The photosensitive drum 61, the charging roller 62, and the developing roller 63 may be provided in the tray 51 instead of in the cartridge P.

[0026] The transfer unit 40 is a belt unit including a belt 41, a primary transfer roller 42, a cleaning unit 43, a drive roller 46 that drives the belt 41, and a tension roller (driven roller) 47. The printer 1 in the first embodiment is provided with an optical sensor 44 that detects the toner image transferred to the belt 41. In the first embodiment, the belt 41 is disposed below the photosensitive drum 61. The belt 41 can contact the photosensitive drum 61 so as to form a primary transfer portion (transfer nip) between the belt 41 and the photosensitive drum 61. The printer 1 also includes a secondary transfer roller 45 that contacts the belt 41 to form a secondary transfer portion (transfer nip) between the belt 41 and the secondary transfer roller 45. The rotational axes of the primary transfer roller 42, the drive roller 46, the tension roller 47, and the secondary transfer roller 45 are parallel to the left-right direction of the printer 1. A registration roller pair 4 is disposed upstream of the secondary transfer portion in the conveyance direction of the sheet S.

[0027] The fixing device 80 has a fixing section 81 and a flapper 5. When an image forming operation is performed on the sheet S, the fixing device 80 is in the fixing position. The fixing device 80 is stored inside the apparatus main body 1A when in the fixing position, and is configured to be able to heat the sheet S. The fixing device 80 is also configured to be able to move between the fixing position and a retracted position that does not interfere with the pull-out operation of the tray unit 50. In the first embodiment, the fixing section 81 is a heating element having a heater. It includes a heating section (heating roller) and a pressure section (pressure roller).

[0028] The movement of the transfer unit 40 and the tray unit 50 will be described using Figures 1, 2, 3, 4, and 5. Figure 2 is a diagram showing the printer 1 with the door 20 open. Figure 3 is a diagram showing the printer 1 with the fixing device 80 in the retracted position. Figure 4 is a diagram showing the printer 1 with the transfer unit 40 and the tray unit 50 pulled out from the device main body 1A. Figure 5 is a diagram showing the printer 1 with the transfer unit 40 pulled out alone from the device main body 1A. Figures 2, 3, 4, and 5 are all schematic cross-sectional views of the printer 1 as viewed from the left to right.

[0029] The transfer unit 40 and the tray unit 50 are attached to the device main body 1A so that they can be pulled out from the device main body 1A through an opening 1A1 in the device main body 1A. In other words, the transfer unit 40 and the tray unit 50 are configured to be movable from the inside to the outside of the device main body 1A. In the front-rear direction H, the device main body 1A has a first end 1b1 on the front side where the opening 1A1 is provided and a second end 1b2 on the rear side opposite the first end 1b1. The tray unit 50 is movable through the opening 1A1 to a first inner position inside the device main body 1A and a first outer position outside the device main body 1A. The transfer unit 40 is movable through the opening 1A1 to a second inner position inside the device main body 1A and a second outer position outside the device main body 1A. In the first embodiment, a common opening 1A1 is provided through which the tray unit 50 and the transfer unit 40 move. However, the device main body 1A may also be provided with separate openings for the tray unit 50 to move through and the transfer unit 40 to pass through. Here, the units (transfer unit 40 and tray unit 50) being located outside the apparatus main body 1A means that at least a part of the unit is located outside the apparatus main body 1A, and it is not necessary that the entire unit is located outside the apparatus main body 1A. In the first embodiment, when the transfer unit 40 is located at the second outer position, at least a part of the belt 41 protrudes forward from the apparatus main body 1A through the opening 1A1.

[0030] The direction in which the tray unit 50 moves from the first inner position to the first outer position is referred to as the first removal direction Dd1, and the direction opposite to the first removal direction Dd1 is referred to as the first attachment direction Da1. The first removal direction Dd1 is the direction from the second end 1b2 (rear side) to the first end 1b1 (front side).

[0031] Furthermore, when the tray unit 50 is attached to the device main body 1A, the direction parallel to the left-right direction of the printer 1 is defined as the width direction of the tray unit 50. Furthermore, the extension direction of the tray 51 that intersects with the width direction of the tray unit 50 is defined as the longitudinal direction of the tray unit 50. In the first embodiment, when the tray unit 50 is attached to the device main body 1A in the first inner position, the longitudinal direction of the tray unit 50 intersects with the front-rear direction H.

[0032] The direction in which the transfer unit 40 moves from the second inner position to the second outer position is called the second take-out direction Dd2, and the opposite direction to the second take-out direction Dd2 is called the second attachment direction Da2. In the second take-out direction Dd2, the drive roller 46 is positioned downstream of the tension roller 47. The second take-out direction Dd2 is the direction from the second end 1b2 (rear side) toward the first end 1b1 (front side).

[0033] Furthermore, when the transfer unit 40 is attached to the device main body 1A, the direction parallel to the left-right direction of the printer 1 is defined as the width direction of the transfer unit 40. Furthermore, the direction intersecting the width direction of the transfer unit 40 and parallel to the line connecting the rotation center of the drive roller 46 and the rotation center of the tension roller 47 is defined as the longitudinal direction of the transfer unit 40. In the first embodiment, when the transfer unit 40 is attached to the device main body 1A in the second inner position, the longitudinal direction of the transfer unit 40 intersects with the front-rear direction H.

[0034] The first take-out direction Dd1 and the first attachment direction Da1 are directions that intersect (preferably, are perpendicular to) the rotational axis direction of the photosensitive drum 61. The second take-out direction Dd2 and the second attachment direction Da2 are directions that intersect (preferably, are perpendicular to) the rotational axis direction of the drive roller 46. The rotational axis direction of the drive roller 46 is parallel to the rotational axis direction of the photosensitive drum 61.

[0035] The fixing device 80 is disposed on the first end 1b1 side of the apparatus main body 1A in the front-rear direction H. The fixing device 80 is located on the first end 1b1 side of the tray unit 50 located at the first inner position.

[0036] Door 20 attached to apparatus main body 1A is movable between a closed position and an open position. As shown in Fig. 1, when door 20 is in the closed position (door 20 closed state), door 20 covers opening 1A1. As shown in Fig. 2, when door 20 is in the open position (door 20 open state), opening 1A1 is exposed.

[0037] 1, when the door 20 is in the closed position, the door 20 covers the fixing device 80 attached to the device main body 1A. More specifically, when the door 20 is in the closed position, the upper cover portion 20b of the door 20 is located above the fixing device 80 and covers the fixing device 80 from above. The upper cover portion 20b of the door 20 functions as a part of the exterior of the printer 1.

[0038] The door 20 can move between an open position and a closed position while the fixing device 80 is supported by the apparatus main body 1A. In other words, the door 20 moves from the closed position to the open position so as to move away from the fixing device 80 supported by the apparatus main body 1A. Therefore, as shown in FIG. 2, when the door 20 is in the open position, the door 20 is away from the fixing device 80 supported by the apparatus main body 1A.

[0039] The fixing device 80 is movable from the fixing position shown in FIG. 2 to the retracted position shown in FIG. 3 so that the opening 1A1 is widely exposed. The movement mechanism of the fixing device 80 will be described in detail later. When the door 20 is in the open position and the fixing device 80 is in the retracted position (the state shown in FIG. 3), the transfer unit 40 and the tray unit 50 can be moved from the inside to the outside of the device main body 1A through the opening 1A1. FIG. 4 shows the transfer unit 40 and the tray unit 50 moved (pulled out) to the outside of the device main body 1A.

[0040] With the tray unit 50 moved to the outside of the apparatus main body 1A (the state shown in FIG. 4), it is possible to remove the cartridges PY, PM, PC, and PK from the tray 51 and to attach the cartridges PY, PM, PC, and PK to the tray 51. This allows the cartridges PY, PM, PC, and PK to be replaced with new cartridges PY, PM, PC, and PK. In the first embodiment, the cartridge P is detachable from the tray 51 in a direction intersecting (preferably a direction perpendicular to) the rotation axis of the photosensitive drum 61.

[0041] The cartridges PY, PM, PC, and PK are removed from the tray 51 by moving in a direction away from the transfer unit 40 relative to the tray 51. In other words, the cartridges PY, PM, PC, and PK are removed from the tray 51 by moving in a direction opposite to the transfer unit 40 side relative to the tray 51. In the first embodiment, the transfer unit 40 is disposed below the tray unit 50. Therefore, the cartridges PY, PM, PC, and PK are removed from the tray 51 by moving upward relative to the tray 51.

[0042] The transfer unit 40 can be pulled out together with the tray unit 50 from the apparatus main body 1A. The transfer unit 40 can be pulled out from the device main body 1A independently of the tray unit 50. In other words, the user of the printer 1 can choose to move only the transfer unit 40, or to pull out the transfer unit 40 together with the tray unit 50. How to pull out the transfer unit 40 and tray unit 50 will be described in detail below.

[0043] [Image formation operation] 1, the image forming operation of the printer 1 will be described. The control unit 3 of the printer 1 starts the image forming operation on the sheet S based on an image signal received from an external host device 400. The external host device 400 is, for example, a personal computer, an image reader, or a facsimile machine.

[0044] When an image is formed on the sheet S, the fixing device 80 is located at the fixing position, the tray unit 50 is located at the first inner position, the transfer unit 40 is located at the second inner position, and the door 20 is located at the closed position. With the transfer unit 40 located at the second inner position, the belt 41 can be brought into contact with the photosensitive drum 61. A contact / separation mechanism for bringing the photosensitive drum 61 into contact with and separating the belt 41 may also be provided. At this time, the tray unit 50 is located above the transfer unit 40.

[0045] During the image forming operation, a charging voltage is applied to the charging roller 62, and the photosensitive drum 61 rotates. Then, a laser corresponding to image information is irradiated from the scanner 2 onto the photosensitive drum 61, and the surface of the photosensitive drum 61 charged by the charging roller 62 is exposed to the light. As a result, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum 61.

[0046] The developing roller 63 carries toner. A developing voltage is applied to the developing roller 63, and the electrostatic latent image formed on the photosensitive drum 61 is developed with toner supplied from the developing roller 63, forming a toner image on the surface of the photosensitive drum 61. In the first embodiment, the developing roller 63 develops the electrostatic latent image while in contact with the photosensitive drum 61, but the developing roller 63 may also develop the electrostatic latent image while there is a gap between the developing roller 63 and the photosensitive drum 61.

[0047] When a full-color image is formed on the sheet S, a toner image of each color is formed on the photosensitive drum 61 of each cartridge P.

[0048] In the first embodiment, when the tray unit 50 is in the first inner position, the developing roller 63 is movable between a contact position where it contacts the photosensitive drum 61 and a spaced position where it is spaced from the photosensitive drum 61. Specifically, a switching device provided in the apparatus main body 1A switches between a state where the developing roller 63 is in the contact position and a state where the developing roller 63 is in the spaced position. This allows the developing roller 63 to be spaced from the photosensitive drum 61 when no image forming operation is being performed.

[0049] The printer 1 can perform monochrome printing when the developing roller 63 and photosensitive drum 61 corresponding to the cartridge PK are in contact with each other and the developing rollers 63 and photosensitive drums 61 corresponding to the cartridges PY, PM, and PC are spaced apart from each other. The printer 1 can also perform full-color printing when the photosensitive drums 61 and belt 41 corresponding to the cartridges PY, PM, PC, and PK are in contact with each other.

[0050] The toner images formed on the respective photosensitive drums 61 are transferred onto the belt 41 at the primary transfer portion, and are conveyed toward the secondary transfer portion formed by the belt 41 and the secondary transfer roller 45 .

[0051] The apparatus main body 1A includes a conveying path (first path, first A double-sided conveying path (second path, second conveying path) 20a is formed in the door 20. The sheet S is conveyed from the sheet feeding section 30 to the fixing device 80 through the conveying path 1c by a conveying section formed of a plurality of rollers and the like. The door 20 also has a double-sided conveying path (second route, second conveying path) 20a through which the sheet S passes after passing through the fixing device 80. The door 20 covers the conveying path 1c when in a closed state. It can also be said that the door 20 functions as a conveying path forming section that forms the conveying path 1c together with the apparatus main body 1A. When the door 20 is opened, the conveying path 1c and the double-sided conveying path 20a are exposed, as shown in FIG. 2.

[0052] In the sheet feeding unit 30, one sheet S is separated and fed by a supply roller 32 at a predetermined timing from a stacking tray 31 on which sheets S are stacked, and the sheet S is conveyed through a conveying path 1c toward a secondary transfer unit and a fixing device 80. Then, the toner image formed on the belt 41 and the sheet S arrive at the secondary transfer unit in time with each other.

[0053] At the secondary transfer portion, a toner image is transferred from belt 41 to sheet S. Toner that has not been transferred to sheet S is removed from belt 41 by a cleaning blade (cleaning member) 43A provided in cleaning portion 43. Cleaning portion 43 is disposed downstream of the secondary transfer portion and upstream of the primary transfer portion in the rotation direction of belt 41 during image formation. Note that the rotation direction of belt 41 during image formation is counterclockwise in FIG. 1.

[0054] The sheet S onto which the toner image has been transferred in the secondary transfer unit is transported toward the fixing device 80. In the fixing device 80, the sheet S is heated and pressurized in a fixing unit 81, and the toner image is fixed onto the sheet S. The sheet S onto which the toner image has been fixed is transported toward a flapper 5 serving as a path switching unit.

[0055] The flapper 5 is movable between a paper discharge position where the sheet S that has passed through the fixing device 80 is guided toward a paper discharge path 1d and a reversing position where the sheet S is guided toward a reversing path 1e.

[0056] When single-sided printing is performed, in which an image is formed on one side of the sheet S, the sheet S is guided to the paper discharge path 1d by the flapper 5 and discharged onto a discharge tray 1f formed on the top of the apparatus main body 1A.

[0057] On the other hand, when double-sided printing is performed, in which images are printed on both sides (front and back) of the sheet S, the sheet S is guided to the reversing path 1e by the flapper 5. After the sheet S is guided to the reversing path 1e, the conveying direction of the sheet S is reversed, and the sheet S is conveyed toward the secondary transfer unit through the double-sided conveying path 20a formed in the door 20. After the toner image is transferred to the back side of the sheet S in the secondary transfer unit, the sheet S passes through the fixing device 80, is guided by the flapper 5 to the paper discharge path 1d, and is discharged onto the discharge tray 1f of the apparatus main body 1A.

[0058] [Layout of various units] 1, 2, 3, 4, and 5, the layout of various units constituting the apparatus main body 1A, such as the tray unit 50, transfer unit 40, and fixing device 80, will be described. In particular, the movement space (movement trajectory) of the tray unit 50 and transfer unit 40 when they are pulled out from the apparatus main body 1A, and the layout position of the fixing device 80 will be described in detail.

[0059] The fixing device 80 of the printer 1 is disposed horizontally on the first end 1b1 side of the device main body 1A. The transfer unit 40 and the tray unit 50 move to the outside of the device main body 1A through an opening 1A1 provided on the first end 1b1 side of the device main body 1A.

[0060] In the first embodiment, the fixing device 80 is disposed at a position closer to the first end 1b1 than to the second end 1b2 of the apparatus main body 1A. The distance between first end 1b1 and fixing device 80 is shorter than the distance between fixing device 80 and second end 1b2. Fixing device 80 is disposed at a position closer to first end 1b1 than the midpoint of apparatus body 1A in the horizontal direction, and the distance between first end 1b1 and fixing device 80 in the horizontal direction is shorter than the distance between first end 1b1 and the midpoint of apparatus body 1A.

[0061] When the tray unit 50 moves from the first inner position to the first outer position, the movement direction of the tray unit 50 is a direction (first removal direction Dd1) that intersects with the rotation axis of the photosensitive drum 61. At this time, the tray unit 50 moves so as to move away from the second end 1b2.

[0062] Similarly, when the transfer unit 40 moves from the second inner position to the second outer position, the movement direction of the transfer unit 40 is a direction (second removal direction Dd2) that intersects with the rotation axis of the drive roller 46. At this time, the transfer unit 40 moves away from the second end 1b2.

[0063] The door 20, located on the first end 1b1 side of the device body 1A, covers the opening 1A1 when closed and also covers at least a portion of the conveying path 1c for the sheet S. The door 20 also has a duplex conveying path 20a. If a jam occurs with the sheet S, the user of the printer 1 can remove the sheet S from the first end 1b1 side of the device body 1A and clear the jam. Specifically, by moving the door 20 to the open position, the user can access the conveying path 1c inside the device body 1A and the duplex conveying path 20a of the door 20 to remove the sheet S. Furthermore, if a portion of the sheet S that has passed through the fixing device 80 is exposed outside the device body 1A, the sheet S can be removed by pulling it from outside the device body 1A without opening the door 20.

[0064] Furthermore, the user of the printer 1 can pull out the transfer unit 40 and the tray unit 50 from the first end 1b1 side of the device main body 1A and move them to the outside of the device main body 1A. Similarly, the user can insert the transfer unit 40 and the tray unit 50 into the device main body 1A from the first end 1b1 side of the device main body 1A and move them to the inside of the device main body 1A. In other words, the user can check the status of the transfer unit 40 and the cartridge P, perform maintenance, replace, and other tasks from the first end 1b1 side of the device main body 1A.

[0065] Furthermore, the stacking tray 31 on which the sheets S are stacked can be pulled out from the first end 1b1 side of the device body 1A, so that the user of the printer 1 can replenish the sheets S from the first end 1b1 side of the device body 1A.

[0066] As described above, in the printer 1, the fixing device 80 and the door 20 are disposed on the first end 1b1 side of the device main body 1A. The transfer unit 40 and the tray unit 50 are configured to be movable in and out of the device main body 1A through the opening 1A1 on the first end 1b1 side of the device main body 1A, and the stacking tray 31 is also pulled out from the first end 1b1 side of the device main body 1A. This configuration allows the user to clear jams, access the fixing device 80, install and remove the transfer unit 40 and the tray unit 50, and replenish sheets S from the same direction (the front side in the first embodiment).

[0067] In the first embodiment, the printer 1 has the first end 1b1 side where the door 20 is provided as the front. Therefore, when installing the printer 1, it is sufficient to secure space for performing tasks such as clearing jams and operating the transfer unit 40 and tray unit 50 from the front of the printer 1. On the other hand, it is not necessary to secure space for performing these tasks from the left, right, back, or top of the printer 1. Therefore, with the configuration of the first embodiment, the printer 1 can be installed in a space-saving manner.

[0068] If the transfer unit 40 or the tray unit 50 is pulled out from the second end 1b2 of the device main body 1A, the user will need to access both ends of the device main body 1A to clear the jam and pull out the transfer unit 40 or the tray unit 50. Also, if one of the transfer unit 40 and the tray unit 50 is pulled out from one end of the device main body 1A and the other is pulled out from the other end, the user will need to access both ends of the device main body 1A. This requires space to work from both the front and back of the device main body 1A, which increases the area required to install the printer 1.

[0069] [Positional relationship between the tray unit and the fixing unit] The positional relationship between the tray unit 50 and the fixing device 80 will be described using Figures 1, 2, 3, 4, 6, and 7. Figures 6 and 7 are diagrams illustrating the movement of the transfer unit 40 and the tray unit 50, and are schematic cross-sectional views of the printer 1 as viewed from the left to the right. Figure 6 shows the printer 1 with the door 20 in a closed state, and Figure 7 shows the printer 1 with the door 20 in an open state.

[0070] The tray unit 50 passes through a predetermined space when moving between a first inner position where an image formation operation on a sheet S is performed and a first outer position where replacement of the cartridge P is permitted. Hereinafter, the space through which the tray unit 50 passes when moving from the first inner position to the first outer position (the movement space of the tray unit 50) will be referred to as the first space Q1. The first space Q1 can also be referred to as the path or trajectory through which the tray unit 50 passes when moving from the first inner position to the first outer position (first movement path, first movement trajectory). In Figures 6 and 7, the approximate outlines of the tray unit 50 at the first outer position and the first inner position are indicated by dashed lines, and the first space Q1 is indicated by dotted lines.

[0071] The transfer unit 40 passes through a predetermined space when moving between a second inner position where an image is formed on the sheet S and a second outer position. Hereinafter, the space through which the transfer unit 40 passes when moving from the second inner position to the second outer position (the movement space of the transfer unit 40) will be referred to as the second space Q2. The second space Q2 can also be referred to as the path or trajectory through which the transfer unit 40 passes when moving from the second inner position to the second outer position (the second movement path, the second movement trajectory). In Figures 6 and 7, the approximate outlines of the transfer unit 40 at the second outer position and the second inner position are indicated by dashed lines, and the second space Q2 is indicated by dotted lines.

[0072] When an image forming operation is performed on the sheet S, the fixing device 80 is located at the fixing position as shown in Fig. 6. The fixing device 80 located at the fixing position is located on the first end 1b1 side of the tray unit 50 located at the first inner position, and a portion of the fixing device 80 overlaps with the first space Q1. In other words, when the fixing device 80 is located at the fixing position, at least a portion of the fixing device 80 is located inside the first space Q1.

[0073] 6, in the first embodiment, when the door 20 is in the closed state, at least a portion of the double-sided conveying path 20a provided in the door 20 overlaps with the first space Q1. That is, when the door 20 is in the closed state, at least a portion of the double-sided conveying path 20a is inside the first space Q1.

[0074] When the fixing device 80 is in the fixing position, if the tray unit 50 tries to move from the first inner position to the first outer position, the tray unit 50 interferes with the fixing device 80, restricting the tray unit 50 from being drawn out. Therefore, the fixing device 80 is configured to be able to retreat from the fixing position. Specifically, the fixing device 80 is configured to be able to move between the fixing position and a retreated position retreated from the fixing position. In FIG. 7, the approximate outlines of the fixing device 80 at the retreated position and at the fixing position are shown by dashed lines. When the fixing device 80 has retreated from the fixing position, When located at the retracted position, the entire fixing device 80 is located outside the first space Q1, and the tray unit 50 is allowed to move from the first inner position to the first outer position.

[0075] When the tray unit 50 moves from the first inner position to the first outer position, the tray unit 50 passes below the fixing device 80, which is located in the retracted position. The fixing device 80 is located outside the second space Q2 at both the fixing position and the retracted position. Therefore, the transfer unit 40 can move from the second inner position to the second outer position in both the state where the fixing device 80 is in the fixing position and the state where the fixing device 80 is in the retracted position. Therefore, when only the transfer unit 40 is pulled out from the apparatus main body 1A, there is no need to move the fixing device 80. When the transfer unit 40 moves from the second inner position to the second outer position, the transfer unit 40 passes below the fixing device 80.

[0076] With this configuration, the fixing device 80 can be disposed in the apparatus main body 1A so that a portion of the fixing device 80 at the fixing position overlaps with the first space Q1, which allows the apparatus main body 1A to be made smaller in size compared to a configuration in which the entire fixing device 80 is disposed outside the first space Q1. Note that in the first embodiment, at least a portion of the fixing device 80 overlaps with the space through which the cartridge P passes when the tray unit 50 moves from the first inner position to the first outer position, but the fixing device 80 may be disposed so as to overlap with the space through which the tray 51 passes.

[0077] When the tray unit 50 is pulled out to the outside of the apparatus main body 1A, the door 20 is first moved to the open position as shown in Fig. 2. In the first embodiment, the door 20 can be moved to the open position and the closed position while the fixing device 80 is positioned at the fixing position. Then, while the door 20 is in the open position, the fixing device 80 can be moved from the fixing position to the retracted position so as to move outside the first space Q1 as shown in Fig. 3.

[0078] Furthermore, the fixing device 80 is lifted from the fixing position and moves to a retracted position above the fixing position. In other words, the retracted position is higher than the fixing position. As shown in FIG. 7 , when the fixing device 80 is in the retracted position, at least a portion of the fixing device 80 protrudes from the device main body 1A toward the outside of the device main body 1A. Furthermore, when the fixing device 80 is in the retracted position, at least a portion of the fixing device 80 is located higher than the position of the upper cover portion 20b of the door 20 in the closed position. This allows the size of the printer 1 to be kept small in the vertical direction V when the fixing device 80 is in the fixing position, while ensuring space for the tray unit 50 to move by moving the fixing device 80 to the retracted position. With the fixing device 80 in the retracted position outside the first space Q1, the user can grasp the tray handle 52 and move the tray unit 50 toward the outside of the device main body 1A. Furthermore, since the movement of the door 20 to the closed position is restricted when the fixing device 80 is in the retracted position, it is possible to prevent the door 20 from being closed while forgetting to return the fixing device 80 to the fixing position.

[0079] A specific description will be given of the movement mechanism of the fixing device 80 according to the first embodiment. The fixing device 80 has a fixing frame 80a that supports a fixing section 81. When the fixing device 80 retreats from the fixing position, the fixing frame 80a displaces relative to the apparatus main body 1A while supporting the fixing section 81.

[0080] The fixing device 80 according to the first embodiment is movable between a fixing position and a retracted position while attached to the apparatus main body 1A. When the fixing device 80 is in the retracted position, the entire fixing device 80 is located outside the first space Q1.

[0081] The printer 1 has a connecting member (fixing connecting member, fixing link, arm) 85 movably connected to the apparatus main body 1A. The fixing device 80 is connected to the apparatus main body 1A via the connecting member 85.

[0082] The connecting member 85 is a rotating member that can rotate around a rotation center 85A. The connecting member 85 rotates around a rotation axis extending in the left-right direction of the printer 1. When the tray unit 50 is pulled out of the device main body 1A, the connecting member 85 is moved out of the first space Q1. One end of the connecting member 85 is connected to the fixing device 80, and the other end of the connecting member 85 is connected to the device main body 1A. While supported by the connecting member 85 (while connected to the device main body 1A via the connecting member 85), the fixing device 80 can move from the fixing position to the retracted position and vice versa. The connecting member 85 is rotatably connected to the fixing device 80, so that the fixing device 80 can move to the retracted position while maintaining the same orientation as when it was in the fixing position. In this way, by configuring the fixing device 80 to be connected to the device main body 1A via the connecting member 85, the movement amount of the fixing device 80 when moving between the retracted position and the fixing position can be increased.

[0083] 7, when the tray unit 50 moves from the first inner position to the first outer position, the angle between the movement direction of the tray unit 50 and the horizontal direction is smaller than the angle between the movement direction of the tray unit 50 and the vertical direction V. Furthermore, when the fixing device 80 moves from the fixing position to the retracted position, the movement amount of the fixing device 80 in the vertical direction V is larger than the movement amount of the fixing device 80 in the horizontal direction. In other words, when the fixing device 80 moves from the fixing position to the retracted position, the movement amount of the fixing device 80 in a direction approximately perpendicular to the movement direction of the tray unit 50 is larger than the movement amount of the fixing device 80 in a direction parallel to the movement direction of the tray unit 50.

[0084] The fixing device 80 may be configured to move between the fixing position and the retracted position while attached to the device main body 1A via a guide fixed to the device main body 1A. The method for moving the fixing device 80 to the outside of the first space Q1 is not limited to this. For example, the fixing device 80 may be detachable from the device main body 1A so as to retract from the fixing position, and the fixing device 80 may be moved to the outside of the first space Q1. That is, the fixing device 80 may be positioned outside the first space Q1 by separating it from the device main body 1A and the door 20 (separating it from the main frame 100). Alternatively, the fixing device 80 may be connected to the door 20, and the fixing device 80 may be moved to the outside of the first space Q1 by opening the door 20.

[0085] [Positional relationship between tray unit and transfer unit] The positional relationship between the tray unit 50 and the transfer unit 40 will be described with reference to FIGS. 1, 2, 3, 4, 5, 6, and 7. FIG.

[0086] When an image is formed on the sheet S, the transfer unit 40 is located at the second inner position. As shown in FIGS. 6 and 7, a portion of the transfer unit 40 is located inside the first space Q1. More specifically, the cleaning unit 43, which is part of the transfer unit 40, is located inside the space through which the tray 51 passes when the tray unit 50 moves from the first inner position to the first outer position. This allows the apparatus main body 1A to be more compact than a configuration in which the entire transfer unit 40 at the second inner position is located outside the first space Q1. In the first embodiment, the cleaning unit 43 overlaps the space through which the tray 51 passes, but it may also overlap the space through which the cartridge P passes. Furthermore, portions of the transfer unit 40 other than the cleaning unit 43 may overlap the first space Q1. In the first embodiment, the cleaning member 43A of the transfer unit 40 at the second inner position overlaps the first space Q1.

[0087] In the first embodiment, when the tray unit 50 is in the first inner position and the transfer unit 40 is in the second inner position, the cleaning unit 43 is located downstream of the tray unit 50 in the first removal direction Dd1. In addition, in the vertical direction V, the area (range) where the cleaning unit 43 is located and the area (range) where the tray unit 50 is located at least partially overlap. When the tray unit 50 is pulled out from the apparatus main body 1A, the transfer unit 40 is also pulled out at the same time, so there is no risk that the cleaning section 43 will interfere with the pulling-out operation of the tray unit 50. Furthermore, by moving the tray unit 50 and the transfer unit 40 together, the photosensitive drum 61 is prevented from being exposed when the tray unit 50 moves to the first outer position, and the photosensitive drum 61 can be prevented from being scratched or soiled.

[0088] In the first embodiment, the conveying path 1c overlaps with the first space Q1 and the second space Q2. In other words, the sheet S is conveyed from the sheet feeding section 30 to the fixing device 80 by passing through the first space Q1 and the second space Q2. When the door 20 is closed, at least a portion of the duplex conveying path 20a overlaps with the second space Q2 through which the transfer unit 40 passes when moving from the second inner position to the second outer position. In other words, when the door 20 is closed, at least a portion of the duplex conveying path 20a is inside the second space Q2.

[0089] 4, when the door 20 is in the open position, the tray unit 50 is in the first outer position, and the transfer unit 40 is in the second outer position, the transfer unit 40 supports the tray unit 50 from below. Furthermore, in the first embodiment, the door 20 supports the transfer unit 40. In other words, the transfer unit 40 supported by the door 20 supports the tray unit 50. In this state, it can also be said that the door 20 supports the tray unit 50 via the transfer unit 40.

[0090] [Tray unit and transfer unit engagement structure] The engagement structure of the tray unit 50 and the transfer unit 40 will be described using Figures 8, 9, and 10. Figures 8, 9, and 10 are diagrams illustrating the engagement structure for the tray unit 50 and the transfer unit 40 to engage with each other. Figures 8 and 10 are perspective views showing one end in the longitudinal direction and one end in the width direction of the tray unit 50 and the transfer unit 40. Figure 9 is a diagram showing one end in the longitudinal direction of the tray unit 50 and the transfer unit 40 (near the tension roller 47), and is a side view of the tray unit 50 (transfer unit 40) as seen from the width direction.

[0091] The tray unit 50 includes a locking member (connecting member, lever, stopper) 53 provided on the tray 51. The locking member 53 has a transfer locking portion 53A and is a rotating member that is rotatable around a rotation center 53B. The tray 51 also has a transfer connecting portion 51A that is an engaging portion that engages with the transfer unit 40. The transfer connecting portion 51A is provided at one end of the tray 51 in the longitudinal and width directions, and is formed so as to protrude from the outside toward the inside in the width direction.

[0092] The transfer unit 40 includes a drive roller 46, a tension roller 47, and a transfer frame 48 that supports the four primary transfer rollers 42. The transfer frame 48 is a support member that has a tray connection groove 48A and a lock connection portion 48B and extends from one end to the other end in the longitudinal direction of the transfer unit 40. The tray connection groove 48A opens in the width direction of the transfer unit 40 and in the second attachment direction Da2, and is an engaged portion that engages with the transfer connection portion 51A. The lock connection portion 48B is located on the rotation trajectory of the lock member 53 and is an engaged portion that engages with the lock member 53.

[0093] The tray connecting groove 48A has a surface facing the second mounting direction Da2 and two opposing surfaces extending from the surface in the second mounting direction Da2. When the tray unit 50 is located in the first inner position and the transfer unit 40 is located in the second inner position, as shown in Fig. 9, the transfer connecting portion 51A is located inside the tray connecting groove 48A. At this time, the transfer connecting portion 51A is disposed at a distance from the three surfaces that make up the tray connecting groove 48A.

[0094] The tray connection groove 48A and the transfer connection portion 51A restrict the tray unit 50 from moving relative to the transfer unit 40 in the first removal direction Dd1 and in a direction perpendicular to the first removal direction Dd1. On the other hand, the transfer unit 40 restricts the tray unit 50 from moving relative to the tray unit 50 in the second attachment direction Da2 and in a direction perpendicular to the second attachment direction Da2. In other words, the tray unit 50 and the transfer unit 40 restrict each other from moving relatively in a predetermined direction by more than the distance between the tray connection groove 48A and the transfer connection portion 51A.

[0095] The tray connecting groove 48A and the transfer connecting portion 51A are provided in a total of four locations: near both ends of the tension roller 47 in the direction of the rotation axis of the tension roller 47, and near both ends of the drive roller 46 in the direction of the rotation axis of the drive roller 46. In other words, the engagement structure between the tray unit 50 and the transfer unit 40 is provided at both ends in the longitudinal direction and both ends in the width direction of the tray unit 50 and the transfer unit 40. Therefore, the tray unit 50 can support the transfer unit 40 by the transfer connecting portion 51A abutting against the tray connecting groove 48A from below. Furthermore, the transfer unit 40 can support the tray unit 50 by the tray connecting groove 48A abutting against the transfer connecting portion 51A from below.

[0096] The locking member 53 is configured to be movable between a connection position in which the transfer locking portion 53A engages with the locking connection portion 48B and a release position in which the transfer locking portion 53A is disengaged from the locking connection portion 48B by rotating around the rotation center 53B.

[0097] The lock connecting portion 48B is formed in a groove shape having a surface facing the first removal direction Dd1 and a surface facing the first attachment direction Da1 opposite to the surface. When the locking member 53 is in the coupled position, the transfer locking portion 53A is located between the surface facing the first removal direction Dd1 and the surface facing the first attachment direction Da1 opposite to the surface facing the first removal direction Dd1. Therefore, when the locking member 53 is in the coupled position, the tray unit 50 is restricted from moving in the first removal direction Dd1 relative to the transfer unit 40. Similarly, when the locking member 53 is in the coupled position, the transfer unit 40 is restricted from moving in the second removal direction Dd2 relative to the tray unit 50. However, when the locking member 53 is in the coupled position, there may be play (gap) between the transfer locking portion 53A and the lock connecting portion 48B in the first removal direction Dd1 and the first attachment direction Da1.

[0098] The lock connecting portions 48B and the locking members 53 may be provided at the widthwise ends of the transfer unit 40 and the tray unit 50. That is, two or more lock connecting portions 48B may be provided in the transfer unit 40, and the same number of locking members 53 as the number of lock connecting portions 48B may be provided in the tray unit 50.

[0099] In this way, it can be said that the transfer connecting portion 51A and the locking member 53 function as a tray-side connecting device, and the tray connecting groove 48A and the lock connecting portion 48B function as a transfer-side connecting device. By connecting (engaging) the tray-side connecting device and the transfer-side connecting device, the tray unit 50 and the transfer unit 40 are connected (engaged), and the tray unit 50 and the transfer unit 40 can move integrally.

[0100] 10, the apparatus main body 1A also has an unlocking section 1B. The unlocking section 1B is a section that moves the locking member 53 from the transfer position to the release position. When the tray unit 50 is in the first inner position and the transfer unit 40 is in the second inner position, the unlocking section 1B contacts the locking member 53 so as to lift the locking member 53 from the lock connecting section 48B, and the locking member 53 is in the release position. In this state, the transfer locking section 53A is separated from the lock connecting section 48B, and movement of the transfer unit 40 in the second removal direction Dd2 relative to the tray unit 50 is not restricted.

[0101] When the tray unit 50 is moved in the first removal direction Dd1 with the locking member 53 in the release position, the transfer unit 40 (tray connection groove 48A) is pushed in the second removal direction Dd2 by the transfer connection portion 51A. As a result, the transfer unit 40 is also moved integrally with the tray unit 50 in the second removal direction Dd2. When the tray unit 50 moves a predetermined distance in the first removal direction Dd1, the locking member 53 separates from the lock release portion 1B, moves to the connection position, and engages with the lock connection portion 48B. Therefore, in the process of pulling out the tray unit 50 from the apparatus main body 1A, the locking member 53 moves from the release position to the connection position. Then, with the locking member 53 in the connection position and engaged with the lock connection portion 48B, the tray unit 50 is moved to the first outer position, and the transfer unit 40 is moved to the second outer position.

[0102] When the tray unit 50 is in the first outer position and the transfer unit 40 is in the second outer position, the locking member 53 is in the coupled position and engages with the locking connection portion 48B. When the tray unit 50 is moved in the first attachment direction Da1 with the locking member 53 engaged with the locking connection portion 48B, the locking member 53 pushes the transfer unit 40 (locking connection portion 48B) in the second attachment direction Da2. As a result, the transfer unit 40 is also moved integrally with the tray unit 50 in the second attachment direction Da2.

[0103] When the transfer unit 40 is moved in the second attachment direction Da2 with the lock member 53 engaged with the lock connection portion 48B, the tray unit 50 (transfer connection portion 51A) is pushed in the first attachment direction Da1 by the tray connection groove 48A. As a result, the tray unit 50 is also moved integrally with the transfer unit 40 in the first attachment direction Da1.

[0104] The unlocking portion 1B has a slope at its end in the first removal direction Dd1 that slopes upward toward the first attachment direction Da1. As the tray unit 50 moves from the first outer position to the first inner position, the locking member 53 abuts against the slope and gradually rotates in a direction away from the lock connecting portion 48B. Once the locking member 53 climbs over the slope of the unlocking portion 1B, it is supported by the unlocking portion 1B and is positioned at the unlocked position.

[0105] As described above, when the tray unit 50 and the transfer unit 40 are moved integrally toward the inside of the apparatus main body 1A, the lock member 53 is moved to the unlocking position by the lock release section 1B. In this state, even if the tray unit 50 is moved in the first mounting direction Da1, the transfer unit 40 does not move. Meanwhile, in the process of closing the door 20, the force of the secondary transfer roller 45 contacting the transfer unit 40 pushes the transfer unit 40 in the second mounting direction Da2 and pushes it to the back of the apparatus main body 1A (to the second inner position). In other words, the door 20 can push the transfer unit 40 so that the transfer unit 40 is located at the second inner position. Similarly, the door 20 may be configured to push the tray unit 50 so that the tray unit 50 is located at the first inner position.

[0106] On the other hand, when the transfer unit 40 is moved in the second removal direction Dd2 with the locking member 53 in the release position and the tray unit 50 in the first inner position, the transfer unit 40 can be moved from the second inner position to the second outer position independently of the tray unit 50. Therefore, in the printer 1 of the first embodiment, as shown in FIG. 5, with the tray unit 50 positioned inside the device main body 1A (first inner position), the transfer unit 40 can be moved outside the device main body 1A (second outer position). The transfer unit 40 in the second outer position can be removed from the device main body 1A, and the user can replace it with a new transfer unit 40.

[0107] In the first embodiment, when the tray unit 50 is in the first inner position, the tray unit 50 is positioned relative to the apparatus main body 1A independently of the transfer unit 40. When the knit 40 is in the second inner position, the transfer unit 40 is positioned relative to the device main body 1A independently of the tray unit 50. With this configuration, the transfer unit 40 and the tray unit 50 can each be positioned with high precision relative to the device main body 1A. Therefore, when the tray unit 50 is in the first inner position and the transfer unit 40 is in the second inner position, a clearance is provided between the tray connecting groove 48A and the transfer connecting portion 51A.

[0108] Note that the clearance between the tray connecting groove 48A and the transfer connecting portion 51A may be eliminated so that the tray unit 50 and the transfer unit 40 can be positioned relative to each other when the tray unit 50 is in the first inner position and the transfer unit 40 is in the second inner position. In this case, the transfer unit 40 and the tray unit 50 can be positioned relative to each other with high precision.

[0109] [Posture and movement direction of tray unit and transfer unit] Next, the postures and movement directions of the tray unit 50 and the transfer unit 40 will be described in detail. As shown in Figures 1, 6, and 7, the tray unit 50 and the transfer unit 40 are tilted with respect to the horizontal direction (front-rear direction H) when attached to the apparatus main body 1A. In other words, when the tray unit 50 and the transfer unit 40 are attached to the apparatus main body 1A, the longitudinal direction of the tray unit 50 and the longitudinal direction of the transfer unit 40 intersect with the horizontal direction.

[0110] When the tray unit 50 is in the first inner position, the rotational axis of the photosensitive drum 61 of the cartridge PY closest to the first end 1b1 is located higher in the vertical direction V than the rotational axis of the photosensitive drum 61 of the cartridge PK farthest from the first end 1b1.

[0111] When the tray unit 50 is in the first inner position, the four photosensitive drums 61 will be referred to as the first photosensitive drum, the second photosensitive drum, the third photosensitive drum, and the fourth photosensitive drum in order from the farthest from the first end 1b1, and will be described more specifically. The second photosensitive drum is closer to the first end 1b1 than the first photosensitive drum, and the rotation axis of the second photosensitive drum is located higher in the vertical direction V than the rotation axis of the first photosensitive drum. Similarly, the third photosensitive drum is closer to the first end 1b1 than the second photosensitive drum, and the rotation axis of the third photosensitive drum is located higher in the vertical direction V than the rotation axis of the second photosensitive drum. The fourth photosensitive drum is closer to the first end 1b1 than the third photosensitive drum, and the rotation axis of the fourth photosensitive drum is located higher in the vertical direction V than the rotation axis of the third photosensitive drum.

[0112] Here, a line connecting the rotation centers of the photosensitive drums 61 is defined as a line LD. The line LD extends in a direction parallel to the longitudinal direction of the tray unit 50. In the first embodiment, when the tray unit 50 is in the first inner position, the line LD is inclined upward relative to the horizontal direction from the side farther from the first end 1b1 to the side closer to the first end 1b1.

[0113] Furthermore, the contact surfaces of the belt 41 that contact the first, second, third, and fourth photosensitive drums are inclined upward from the side farther from the first end 1b1 to the side closer to the first end 1b1. The contact surfaces extend parallel to the longitudinal direction of the transfer unit 40 and parallel to a line connecting the rotation centers of the drive roller 46 and the tension roller 47.

[0114] When the tray unit 50 moves from the first inner position to the first outer position, the tray unit 50 first moves in a direction inclined relative to the horizontal direction (in the first embodiment, a direction inclined upward relative to the horizontal direction). In other words, when the tray unit 50 moves from the first inner position to the first outer position, the tray unit 50 moves diagonally upward. The movement direction of the unit 50 changes from diagonally upward to downward. In the first embodiment, the movement direction of the tray unit 50 (first removal direction Dd1) changes from diagonally upward to horizontal, but is not limited to this configuration. For example, the movement direction of the tray unit 50 may include a diagonally downward direction relative to the horizontal direction. Conversely, the first attachment direction Da1 of the tray unit 50 changes from horizontal to diagonally downward.

[0115] The angle between the line LD and the horizontal direction is smaller when the tray unit 50 is in the first outer position than when the tray unit 50 is in the first inner position. In the first embodiment, the line LD is parallel to the horizontal direction when the tray unit 50 is in the first outer position, but this configuration is not limited to this. For example, when the tray unit 50 is in the first outer position, the line LD may be inclined with respect to the horizontal direction.

[0116] Similarly, when the transfer unit 40 moves from the second inner position to the second outer position, the movement direction of the transfer unit 40 (second removal direction Dd2) changes from diagonally upward to downward. In the first embodiment, the movement direction of the transfer unit 40 changes from diagonally upward to horizontal, but this is not limited to this configuration. For example, the movement direction of the transfer unit 40 may include a direction diagonally downward relative to the horizontal. Conversely, the second attachment direction Da2 of the transfer unit 40 changes from horizontal to diagonally downward.

[0117] The angle between the longitudinal direction of the transfer unit 40 and the horizontal direction is smaller when the transfer unit 40 is in the second outer position than when the transfer unit 40 is in the second inner position. In the first embodiment, when the transfer unit 40 is in the second outer position, the longitudinal direction of the transfer unit 40 is parallel to the horizontal direction, but the contact surface of the belt 41 may be inclined downward or upward with respect to the horizontal direction.

[0118] When the tray unit 50 is moved from the first outer position to the first inner position, the tray unit 50 moves horizontally and then moves diagonally downward from the middle. When the transfer unit 40 is moved from the second outer position to the second inner position, the transfer unit 40 moves horizontally and then moves diagonally downward from the middle. With this configuration, the weights of the tray unit 50 and the transfer unit 40 can be used when inserting the tray unit 50 and the transfer unit 40 into the apparatus main body 1A.

[0119] [Transfer unit movement path] Next, the movement path of the transfer unit 40 will be described in more detail with reference to Figures 11, 12, 13(a), (b), and 14. As shown in Figure 4, a main guide 90 is attached to the main frame 100. The main guide 90 is an engaging member that engages with the transfer unit 40 and regulates the movement direction of the transfer unit 40.

[0120] FIG. 11 is a diagram illustrating the configuration of the main guide 90. The main guide 90 has an upper guide region 93 and a lower guide region 92 that are partitioned vertically by a wall 91. The upper guide region 93 and the lower guide region 92 are grooves that are formed in the main guide 90 and open in the left-right direction. As shown in FIG. 8, the transfer unit 40 is provided with a transfer shaft 49 that is a shaft-shaped protrusion that extends in the width direction (a direction perpendicular to the second removal direction Dd2). The transfer shaft 49 is a protrusion that fits into the groove-shaped upper guide region 93 and lower guide region 92, and is an engaged portion that engages with the main guide 90. In the first embodiment, the transfer shaft 49 is provided at the downstream end of the transfer unit 40 in the second attachment direction Da2.

[0121] The lower guide area 92 is a passage that branches off from the upper guide area 93 and extends parallel to the upper guide area 93. The lower guide area 92 is provided at a position farther from the tray unit 50 inside the apparatus main body 1A than the upper guide area 93. In the first embodiment, In the example, the upper guide region 93 and the lower guide region 92 extend substantially parallel to each other, but the present invention is not limited to this configuration, and the lower guide region 92 may extend at an angle relative to the upper guide region 93 .

[0122] A cutout portion 91A is provided on the downstream side of the wall 91 in the second attachment direction Da2 (upstream side in the second removal direction Dd2) as an opening connecting the upper guide area 93 and the lower guide area 92. In addition, a cutout portion 91B is provided on the downstream side of the wall 91 in the second removal direction Dd2 as an opening connecting the upper guide area 93 and the lower guide area 92. The cutout portion 91A and the cutout portion 91B each function as a connection portion connecting the upper guide area 93 and the lower guide area 92. In the second removal direction Dd2, the cutout portion 91A is provided on the upstream side of the wall 91, and the cutout portion 91B is provided on the downstream side of the wall 91.

[0123] A slope 92A that slopes upward in the second attachment direction Da2 is provided at the downstream end of the lower guide region 92 in the second attachment direction Da2. Also, a detent portion 92B that extends in a direction intersecting (preferably perpendicular to) the second removal direction Dd2 is provided at the downstream end of the lower guide region 92 in the second removal direction Dd2.

[0124] The upper guide region 93 includes a first region 93A at the downstream end in the second attachment direction Da2, a second region 93B extending parallel to the lower guide region 92, and a third region 93C at the downstream end in the second removal direction Dd2. The first region 93A includes a portion located downstream of the cutout 91A in the second attachment direction Da2. The second region 93B is separated from the lower guide region 92 by the wall 91 and is connected to the lower guide region 92 by the cutouts 91A and 91B. The third region 93C includes a portion located downstream of the cutout 91B in the second removal direction Dd2.

[0125] A tray unit support portion 94 is provided on the upper portion of the main guide 90. The tray unit support portion 94 is configured to be able to support the tray unit 50 from below. Note that a configuration for supporting and guiding the tray unit 50 may be provided independently of the tray unit support portion 94.

[0126] The second region 93B of the upper guide region 93 functions as a first passage through which the transfer shaft 49 passes when the transfer unit 40 is pulled out together with the tray unit 50. Furthermore, the lower guide region 92 branching off from the second region 93B functions as a second passage through which the transfer shaft 49 passes when the transfer unit 40 is pulled out independently from the tray unit 50. Below, the movement path of the transfer unit 40 in each of the cases where the transfer unit 40 is pulled out independently from the tray unit 50 and where the transfer unit 40 is pulled out together with the tray unit 50 will be described in detail.

[0127] (Path of movement when the transfer unit moves independently from the tray unit) First, a detailed description will be given of the movement path of the transfer unit 40 when the transfer unit 40 moves independently of the tray unit 50. Figure 12 is a diagram illustrating the movement path of the transfer unit 40, and the path (trajectory) of the transfer shaft 49 when the transfer unit 40 moves independently of the tray unit 50 from the second inner position to the second outer position is shown by a broken line.

[0128] When the transfer unit 40 is located at the second inner position, the transfer shaft 49 is located within the first region 93A of the upper guide region 93. When the transfer unit 40 moves independently from the second inner position to the second outer position, the transfer shaft 49 passes through the cutout 91A from the first region 93A of the upper guide region 93 of the main guide 90 and enters the lower guide region 92 along the slope 92A, as shown in FIG. 12 . The cutout 91A functions as an entrance for the transfer shaft 49 to enter the lower guide region 92 when the transfer unit 40 is pulled out independently from the tray unit 50. The transfer unit 40 then moves in the second removal direction Dd2 while being guided by the main guide 90 so that the transfer shaft 49 passes through the lower guide area 92. After the transfer shaft 49 moves until it abuts against the detent portion 92B, the transfer unit 40 is lifted up, whereby the transfer shaft 49 passes through the notch portion 91B, enabling the transfer unit 40 to be removed from the apparatus main body 1A. The notch portion 91B functions as an exit for the transfer shaft 49 to exit the lower guide area 92 when the transfer unit 40 is pulled out independently from the tray unit 50. The second outer position of the transfer unit 40 is the position where the transfer shaft 49 abuts against the detent portion 92B.

[0129] When the transfer unit 40 is moved to the second inner position with the tray unit 50 attached to the apparatus main body 1A, the transfer unit 40 follows the above-mentioned movement trajectory in the opposite direction. That is, the transfer shaft 49 enters the lower guide area 92 from the cutout portion 91B, moves through the lower guide area 92 in its extension direction, climbs the inclined surface 92a, and reaches the first area 93A of the upper guide area 93.

[0130] 13(a) and (b) are diagrams illustrating the structure for restricting erroneous entry of the transfer shaft 49. Fig. 13(a) shows the upstream end of the main guide 90 in the second removal direction Dd2. Fig. 13(b) shows the upstream end of the main guide 90 in the second attachment direction Da2.

[0131] When the transfer unit 40 starts to move from the second inner position to the second outer position, the weight of the transfer unit 40 causes the transfer shaft 49 to move from the first region 93A of the upper guide region 93 through the notch 91A and along the slope 92A. However, if the transfer unit 40 is moved in a lifted manner, the transfer shaft 49 may enter the second region 93B of the upper guide region 93. Therefore, in the first embodiment, when the transfer unit 40 moves independently from the tray unit 50, a prevention wall 51B is provided in the tray unit 50 as a limiting portion (first limiting portion) that limits the transfer shaft 49 from moving through the second region 93B to the second outer position. Also, as shown in FIG. 13(a), the transfer unit 40 is provided with an abutting portion 48C. When the transfer shaft 49 attempts to enter the second region 93B while the tray unit 50 is in the first inner position, the abutting portion 48C abuts against the prevention wall 51B of the tray unit 50, restricting the transfer shaft 49 from entering the second region 93B. When the abutting portion 48C abuts against the prevention wall 51B, the transfer shaft 49 is located upstream of the wall 91 in the second removal direction Dd2. More specifically, when the abutting portion 48C abuts against the prevention wall 51B in the second removal direction Dd2, the position of the transfer shaft 49 overlaps with the position of the notch 91A in the second removal direction Dd2. The improper entry restriction structure is configured so that when the abutting portion 48C abuts against the prevention wall 51B, the transfer shaft 49 is located in the notch 91A, which is the connection between the second region 93B and the lower guide region 92.

[0132] The prevention wall 51B has an inclined surface that slopes toward the lower guide region 92 as it advances toward the first removal direction Dd1, and the abutting portion 48C abuts against this inclined surface. Therefore, when an attempt is made to pull out the transfer unit 40 with the abutting portion 48C abutting against the prevention wall 51B, the transfer unit 40 receives a force from the prevention wall 51B via the abutting portion 48C in a direction that moves it toward the lower guide region 92. In other words, the inclined surface of the prevention wall 51B guides the abutting portion 48C so that the transfer shaft 49 approaches the lower guide region 92 as the transfer unit 40 is pulled out to the outside of the apparatus main body 1A. With this configuration, the transfer shaft 49 can be guided into the lower guide region 92 while being restricted from advancing through the second region 93B in the second removal direction Dd2.

[0133] Furthermore, the printer 1 according to the first embodiment includes a restricting structure 70 that restricts the tray unit 50 from moving in the first removal direction Dd1 and being pulled out to the outside of the device main body 1A when the abutting portion 48C is in contact with the preventing wall 51B. This prevents the transfer unit 40 from being drawn out together with the tray unit 50 in a state where the abutting portion 48C is in contact with the prevention wall 51B. The regulation structure 70 will be described in detail later.

[0134] Furthermore, a lower slope portion 91C that slopes downward as it approaches the second removal direction Dd2 is formed at the upstream end of the wall 91 in the second removal direction Dd2. When the transfer shaft 49 moving in the second removal direction Dd2 abuts against the lower slope portion 91C, it receives a downward force from the lower slope portion 91C, and the lower slope portion 91C makes it easier for the transfer shaft 49 to be guided into the lower guide area 92. With this configuration, when the transfer unit 40 is pulled out alone from the apparatus main body 1A, the transfer shaft 49 reliably passes through the lower guide area 92, and the transfer unit 40 can move without interfering with the photosensitive drum 61.

[0135] When the transfer unit 40 is located at the second outer position, the transfer shaft 49 abuts against the detent portion 92B. At this time, the downstream end of the transfer unit 40 in the second removal direction Dd2 is supported by a support portion (not shown) of the door 20, and the center of gravity G1 (see FIG. 5) of the transfer unit 40 is located between the transfer shaft 49 and the downstream end. Therefore, when the transfer unit 40 moves independently from the second outer position to the second inner position, the transfer shaft 49 passes through the lower guide area 92. Then, the transfer shaft 49 moves along the lower guide area 92, ascends the inclined surface 92A, and reaches the upper guide area 93.

[0136] However, when the transfer unit 40 is lifted and moved into the inside of the device main body 1A, such as when replacing the transfer unit 40, there is a possibility that the transfer shaft 49 may enter the second region 93B of the upper guide region 93. Therefore, in the first embodiment, when the tray unit 50 is in the first inner position and the transfer unit 40 moves (inserts) into the inside of the device main body 1A by itself, a prevention wall 51C is provided in the tray unit 50 as a limiting portion (second limiting portion) that prevents the transfer shaft 49 from passing through the second region 93B of the upper guide region 93 and the transfer unit 40 from reaching the second inner position. Also, as shown in FIG. 13(b), the transfer unit 40 is provided with an abutting portion 48D. When the transfer shaft 49 enters the second region 93B, the abutting portion 48D abuts against the prevention wall 51C of the tray unit 50, thereby restricting the movement of the transfer unit 40 in the second installation direction Da2. In Example 1, when the abutting portion 48C abuts against the prevention wall 51B, the transfer shaft 49 is in the second region 93B, but when the abutting portion 48C abuts against the prevention wall 51B, the position of the transfer shaft 49 and the position of the cutout portion 91B may overlap in the direction of the second mounting direction Da2.

[0137] The prevention wall 51C has an inclined surface that slopes toward the lower guide region 92 as it moves in the first mounting direction Da1, and the abutment portion 48D abuts against this inclined surface. Therefore, when an attempt is made to push the transfer unit 40 into the device main body 1A with the abutment portion 48D abutting against the prevention wall 51C, the transfer unit 40 is prevented from moving in the direction of floating up.

[0138] Furthermore, a lower inclined surface 91D that slopes downward in the second mounting direction Da2 and an upper inclined surface 91E that slopes upward in the second mounting direction Da2 are formed at the upstream end of the wall 91 in the second mounting direction Da2. The lower inclined surface 91D is provided so that the transfer shaft 49 can be easily guided into the lower guide area 92.

[0139] As described above, when the transfer unit 40 moves independently of the tray unit 50, the transfer shaft 49 passes through the lower guide area 92. Therefore, the transfer unit 40 can move in the second removal direction Dd2 or the second attachment direction Da2 at a position spaced downward from the tray unit 50. With this configuration, the transfer unit 40 can move smoothly between the second inner position and the second outer position without damaging the photosensitive drum 61, with the belt 41 and the like spaced apart from the photosensitive drum 61.

[0140] (Path of movement when the transfer unit moves together with the tray unit) Next, a detailed description will be given of the movement path of the transfer unit 40 when the transfer unit 40 moves together with the tray unit 50. Figure 14 is a diagram illustrating the movement path of the transfer unit 40, and the path (trajectory) of the transfer shaft 49 when the transfer unit 40 moves together with the tray unit 50 from the second inside position to the outside of the apparatus main body 1A is shown by a broken line.

[0141] When the tray unit 50 moves from the first inner position to the first outer position while connected to the transfer unit 40, the lower surface of the tray unit 50 is supported by the tray unit support portion 94. Meanwhile, the transfer unit 40 moves together with the tray unit 50 while being supported from below by the transfer connecting portion 51A of the tray unit 50. Therefore, when the transfer unit 40 moves together with the tray unit 50, the transfer shaft 49 does not fall into the lower guide region 92, but enters the second region 93B and moves along the upper guide region 93. Note that, although the first embodiment is configured such that the main guide 90 supports the tray unit 50, a configuration in which a support member different from the main guide 90 supports the tray unit 50 may also be used.

[0142] A rotatable roller 94A is provided at the end of the tray unit support portion 94 on the second removal direction Dd2 side. The tray unit 50 can move smoothly on the roller 94A, reducing the load on the user when pulling out the tray unit 50.

[0143] When the center of gravity G2 (see FIG. 4) of the tray unit 50 and the transfer unit 40 is downstream of the rotating roller 94A in the second mounting direction Da2, the tray unit 50 moves while being supported by the tray unit support portion 94. At this time, the tray unit 50 moves while being supported by the rotating roller 94A and a surface 94B downstream of the rotating roller 94A in the second mounting direction Da2.

[0144] When the center of gravity G2 of the tray unit 50 and the transfer unit 40 is downstream of the roller 94A in the second removal direction Dd2, the underside 51D of the tray unit 50 moves away from the surface 94B of the tray unit support portion 94, and the tray unit 50 moves while being supported by the roller 94A. The upper surface of the second region 93B of the upper guide region 93 has a flat portion 95 that extends linearly and a curved portion 96 that forms an arc upward from the downstream end of the wall 91 in the second removal direction Dd2. When the transfer shaft 49 passes through the second region 93B of the upper guide region 93, the transfer shaft 49 comes into contact with the flat portion 95 and the curved portion 96, thereby limiting the tilt of the tray unit 50 and the transfer unit 40 during movement.

[0145] When the tray unit 50 and the transfer unit 40 are further pulled out from a state in which the transfer shaft 49 is positioned in the second region 93B, the transfer shaft 49 slides against the curved surface 96, and the orientation of the tray unit 50 and the transfer unit 40 transitions from an inclined state to a horizontal state. The transfer unit 40 is then supported by the support portion of the door 20, and the tray unit 50 is supported by the door 20 via the transfer unit 40. At this time, the tray connecting groove 48A of the transfer unit 40 supports the transfer connecting portion 51A of the tray unit 50 from below. The tray unit 50 is supported by the door 20 via the transfer unit 40, and the position of the tray unit 50 at which the cartridge P and the tray unit 50 can be removed from the apparatus main body 1A is the first outer position. Furthermore, when the transfer unit 40 is pulled out together with the tray unit 50 from the apparatus main body 1A, the transfer unit 40 is supported by the support portion of the door 20 at a position different from the second outer position. That is, the position (first position) when the transfer unit 40 is pulled out together with the tray unit 50 is different from the position (second position, second outer position) when the transfer unit 40 is pulled out independently from the tray unit 50. In the first embodiment, the second position is closer to the apparatus main body 1A than the first position.

[0146] The underside of the transfer unit 40 is such that when the transfer unit 40 is pulled out alone to the outside of the device body, In either case, when the transfer unit 40 is in the second outer position (second position), or when it is connected to the tray unit 50 and pulled out to the outside of the apparatus main body, the transfer unit 40 is supported by the support portion of the door 20. The transfer unit 40 is removable from the apparatus main body 1A when it is in the second outer position (second position).

[0147] As described above, when the tray unit 50 moves from the first outer position to the first inner position together with the transfer unit 40, the transfer unit 40 is supported from below by the tray unit 50. Therefore, the transfer shaft 49 can move through the cutout portion 91B without falling into the lower guide area 92. Furthermore, an upper inclined surface portion 91E is provided at the upstream end of the wall 91 of the main guide 90 in the first mounting direction Da1, which prevents the transfer shaft 49 from getting caught on the wall 91.

[0148] When the tray unit 50 moves from the first outer position to the first inner position together with the transfer unit 40, if the transfer shaft 49 comes into contact with the curved surface portion 96, the transfer shaft 49 receives a downward force with the rotating roller 94A as the fulcrum. Then, the tray unit 50 receives a force in a direction that lifts the tray handle 52 via the transfer unit 40. As a result, the tray unit 50 and the transfer unit 40 move while changing their posture in accordance with the curved surface portion 96. Then, if the center of gravity G2 moves downstream of the rotating roller 94A in the second attachment direction Da2, the tray unit 50 is pulled into the first inner position by its own weight.

[0149] As described above, when the transfer unit 40 moves together with the tray unit 50, the transfer shaft 49 passes through the upper guide area 93, allowing the tray unit 50 to move smoothly between the first inner position and the first outer position.

[0150] In the above description, the main guide 90 is provided on one widthwise end side of the tray unit 50 and the transfer unit 40, but a guide member (engagement member) symmetrical in shape to the main guide 90 is also provided on the other widthwise end side of the tray unit 50 and the transfer unit 40. In other words, the transfer unit 40 moves between the inside and outside of the device main body 1A while engaging with engagement members provided on the device main body 1A at both widthwise ends.

[0151] Furthermore, in the above description, the transfer unit 40 is configured to be able to pass through multiple paths, but this configuration is not limited to this. For example, a first unit and a second unit different from the transfer unit 40 and the tray unit 50 may be provided. Even in this case, the second unit can be configured to pass through different paths when it is pulled out from the device main body 1A together with the first unit and when it is pulled out from the device main body 1A independently of the first unit. In this case, the first unit and the second unit may refer to individual parts or members.

[0152] [Tray unit regulation structure] A restriction structure 70 that restricts movement of the tray unit 50 will be described using Figures 15, 16(a) to 16(c), and 17. Because the tray unit 50 is supported by the door 20 via the transfer unit 40 at the first outer position, there is a risk that the tray unit 50 will not be properly supported if it is pulled out to the first outer position by itself. In other words, it is desirable to configure the tray unit 50 so that it cannot move to the first outer position when the transfer unit 40 is at the second outer position or is in the process of moving to the second outer position. Therefore, the printer 1 according to the first embodiment is provided with a restriction structure 70 (see Figure 5) that restricts the tray unit 50 from moving alone to the outside of the device main body 1A.

[0153] 15 is a perspective view showing the configuration of the regulating structure 70. The regulating structure 70 includes a regulating member 71 that regulates the tray unit 50 from moving to the first outer position when the transfer unit 40 is at a position away from the second inner position, a holding member 72 that holds the regulating member 71, and a regulating member The regulating member 71 includes a spring 73 that biases the regulating member 71. The regulating member 71 is held by the holding member 72 so as to be rotatable about a rotation axis 71a. The regulating member 71 is configured to be rotatable between a non-regulating position where it does not regulate the movement of the tray unit 50, and a regulating position where it regulates the movement of the tray unit 50. The rotation axis 71a extends in a direction intersecting (preferably perpendicular to) the longitudinal and width directions of the tray unit 50 positioned in the first inner position. The regulating member 71 also has a positioned portion 71b that engages (abuts) with a positioning portion 72a of the holding member 72 to determine its position in a direction parallel to the rotation axis 71a.

[0154] The holding member 72 is installed on the surface of the main frame 100 of the printer 1 opposite to the surface facing the tray unit 50. In other words, the main frame 100 is disposed between the rotation axis 71a of the holding member 72 and the regulating member 71 and the tray unit 50 and the transfer unit 40.

[0155] The regulating member 71 has a rotation shaft portion 71i that rotates around a rotation axis 71a, a connection portion 71j that extends from the rotation shaft portion 71i in a direction intersecting the rotation axis 71a, and a tray regulating portion 71c and a transfer detecting portion 71d that extend from the connection portion 71j in the direction of extension of the connection portion 71j and in a direction intersecting the rotation axis 71a. The connection portion 71j extends in parallel from the upper and lower portions of the rotation shaft portion 71i and is connected to the upper and lower ends at the ends of the extensions. The above-mentioned positioned portion 71b is a part of the connection portion 71j.

[0156] The tray regulating portion 71c is a regulating portion (contact portion) that extends from the upper portion of the connecting portion 71j and abuts against the tray lock portion 50a of the tray unit 50 to regulate the position of the tray unit 50. The transfer detecting portion 71d is a contact portion that extends from the lower portion of the connecting portion 71j substantially parallel to the extending direction of the tray regulating portion 71c and abuts against the transfer side surface 40a of the transfer unit 40. An opening 100a is also provided in the main frame 100. The tray regulating portion 71c and the transfer detecting portion 71d are arranged to straddle the opening 100a from the side of the rotation axis 71a to the side of the tray unit 50 (transfer unit 40). In other words, portions of the tray regulating portion 71c and the transfer detecting portion 71d are located inside the opening 100a.

[0157] 16(a), 16(b), and 17 are views of the regulating structure 70 viewed from above in a direction parallel to the rotation axis 71a. FIG. 16(c) is a view of the regulating structure 70 viewed from the left and right of the printer 1 (the width direction of the tray unit 50). FIG. 16(a) shows the regulating member 71 in the non-regulating position and abutting against the transfer unit 40. When the transfer unit 40 is in the second inner position or nearby, the transfer detection portion 71d of the regulating member 71 abuts against the transfer side surface 40a. At this time, the regulating member 71 is biased by the spring 73 in a direction in which the transfer detection portion 71d presses against the transfer side surface 40a, but the transfer side surface 40a restricts its rotation (movement), thereby fixing its position. Also, at this time, the tray regulating portion 71c is located outside the first space Q1, which is the movement space of the tray unit 50. Therefore, the tray unit 50 can move between the first inner position and the first outer position without being restricted by the restricting member 71.

[0158] On the other hand, when the transfer unit 40 is at the second outer position, or when it is moving to the second outer position and is away from the second inner position, the transfer detection portion 71d does not come into contact with the transfer unit 40. Then, the regulating member 71 is biased by the spring 73 to rotate in the direction of the arrow Dr, and the frame abutment portion 71h of the regulating member 71 abuts against the surface of the main frame 100 on the holding member 72 side.

[0159] 16(b) and (c) show the state in which the regulating member 71 is located at the regulating position and the tray unit 50 abuts against the regulating member 71. When the regulating member 71 abuts against the main frame 100, not against the transfer unit 40, the tray regulating portion 71c is located inside the first space Q1 (movement space of the tray lock portion 50a). More specifically, the tray unit 50 is positioned at the end in the width direction thereof. The tray restricting portion 71c is positioned at a position overlapping with a movement locus 50a1 of the tray locking portion 50a that protrudes from the tray restricting portion 71c toward the rotation axis 71a. Therefore, when the restricting member 71 is positioned by abutting against the main frame 100 without abutting against the transfer unit 40, the tray locking portion 50a abuts against the tray restricting portion 71c, and movement of the tray unit 50 in the first removal direction Dd1 is restricted. At this time, a surface 50a2 of the tray locking portion 50a abuts against a surface 71c1 of the tray restricting portion 71c, and the restricting member 71 is pressed by the tray unit 50. Then, a surface 71c2 of the tray restricting portion 71c facing the opposite side to the surface 71c1 abuts against the edge of the opening 100a of the main frame 100.

[0160] In the first embodiment, when the transfer unit 40 moves independently in the second removal direction Dd2 and the abutting portion 48C of the transfer unit 40 abuts against the prevention wall 51B of the tray unit 50, the tray lock portion 50a abuts against the regulating member 71. Therefore, if an attempt is made to pull out the transfer unit 40 independently from the tray unit 50 and the transfer unit 40 pushes the tray unit 50, the regulating structure 70 restricts the tray unit 50 from being pulled out together with the transfer unit 40.

[0161] The surface 71c1 of the tray restrictor 71c and the surface 50a2 of the tray locking portion 50a are each inclined with respect to a plane perpendicular to the longitudinal direction of the tray unit 50 located at the first inner position. Specifically, the surface 71c1 of the tray restrictor 71c is inclined in a direction away from the upper end of the opening 100a as it approaches the first removal direction Dd1. Similarly, the surface 50a2 of the tray locking portion 50a is inclined in a direction away from the upper end of the opening 100a as it approaches the first removal direction Dd1. Therefore, when the tray locking portion 50a pushes the tray restrictor 71c in the first removal direction Dd1, the tray restrictor 71c is pushed from the tray locking portion 50a toward the upper edge of the opening 100a and abuts against the upper edge. With this configuration, the force with which the tray locking portion 50a of the tray unit presses the tray regulating portion 71c can be distributed to the main frame 100, thereby suppressing deformation or damage to the tray regulating portion 71c and more reliably regulating the movement of the tray unit 50.

[0162] Furthermore, when the tray unit 50 moves from the first outer position to the first inner position, the transfer unit 40 also moves with the tray unit 50. Then, the tip of the transfer side surface 40a (the end of the transfer unit 40 on the second mounting direction Da2 side) abuts against the inclined surface 71d1 formed at the tip of the transfer detection portion 71d. Then, the regulating member 71 rotates (moves) from the regulating position to the non-regulating position, and the tray regulating portion 71c retreats from the movement trajectory 50a1 of the tray lock portion 50a. Therefore, the regulating member 71 does not regulate the movement of the tray unit 50 in the first mounting direction Da1. Similarly, when the transfer unit 40 moves alone from the second outer position to the second inner position in the second mounting direction Da2, the regulating member 71 is pushed by the transfer unit 40 and rotates against the biasing force of the spring 73. Therefore, the regulating member 71 does not regulate the movement of the transfer unit 40 in the second mounting direction Da2.

[0163] As described above, in the first embodiment, when the transfer unit 40 is away from the second inner position, the regulating structure 70 regulates the movement of the tray unit 50 from the first inner position to the first outer position.

[0164] The configuration of the restriction structure is not limited to the above. For example, the movement of the tray unit 50 may be restricted by a structure in which a member that moves linearly between a restricted position and a non-restricted position is provided, instead of a rotating member that receives a biasing force.

[0165] [Variations] Next, a modified example of the first embodiment will be described. In the first embodiment, the photosensitive drum 61, the charging roller 62, and the developing roller 63 are provided in the cartridge P. Therefore, modified examples will be described by way of example with reference to Figures 18(a) to 18(d). Figures 18(a) to 18(d) are views showing tray units 50 according to modified examples.

[0166] For example, as shown in FIG. 18( a ), the tray 51 may have a photosensitive drum 61 and a charging roller 62 , and the cartridge P may have a developing roller 63 .

[0167] 18(b), the cartridge P may include a drum cartridge P1 having a photosensitive drum 61 and a charging roller 62, and a developer cartridge P2 having a developing roller 63. In other words, the cartridge P may be separable into the drum cartridge P1 and the developer cartridge P2. In this case, it is preferable that the drum cartridge P1 and the developer cartridge P2 be attachable to and detachable from the tray 51 independently of each other.

[0168] 18(c), the cartridge P may include a cartridge PR having a photosensitive drum 61, a charging roller 62, and a developing roller 63, and a cartridge PT having toner for replenishing the cartridge PR. In other words, the cartridge P may be separable into the cartridge PR and the cartridge PT.

[0169] 18(d), the cartridge P may include a drum cartridge P1 having a photosensitive drum 61 and a charging roller 62, a developer cartridge P2 having a developing roller 63, and a cartridge PT having toner for replenishing the developer cartridge P2. In other words, the cartridge P may be separable into the drum cartridge P1, the developer cartridge P2, and the cartridge PT.

[0170] <Example 2> Next, a second embodiment of the present invention will be described with reference to Figures 19, 20, and 21. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and will not be described again, and the description will focus mainly on the characteristic parts of the second embodiment.

[0171] [Configuration of image forming device] 19 is a diagram illustrating the overall configuration of a printer 401 as an image forming apparatus according to Example 2. The printer 401 as an image forming apparatus according to Example 2 includes a device main body 401A in which an opening 401A1 is formed, and a door 420. The printer 401 corresponds to the printer 1 of Example 1, the device main body 401A corresponds to the device main body 1A of Example 1, and the opening 401A1 corresponds to the opening 1A1 of Example 1.

[0172] In the first embodiment, the toner image formed on the photosensitive drum 61 is transferred to the belt 41 of the transfer unit 40, and then transferred from the belt 41 to the sheet S at a secondary transfer portion. That is, the transfer unit 40 according to the first embodiment functions as a so-called intermediate transfer unit. On the other hand, in the second embodiment, the printer 401 includes a transfer unit 440 as a second unit configured to be removable from the apparatus main body 401A, in addition to the tray unit 50 as a first unit similar to that of the first embodiment. The transfer unit 440 transports the sheet S with a belt (conveyor belt) 441 so that the sheet S comes into contact with the photosensitive drum 61 and the toner image is transferred from the photosensitive drum 61 to the sheet S. That is, the transfer unit 440 in the second embodiment functions as a so-called conveyor belt unit.

[0173] A printer 401 as an image forming apparatus in the second embodiment includes an apparatus main body 401A, a sheet feeding unit 430, and a transfer unit 440. As in the first embodiment, a fixing device 80 is disposed on the first end 1b1 side of the apparatus main body 401A.

[0174] The transfer unit 440 includes a belt 441 that conveys the sheet S, four primary transfer rollers 442, a drive roller 446, and a tension roller 447. The printer 401 in the second embodiment is provided with an optical sensor 44 that detects the toner image transferred onto the belt 441.

[0175] FIG. 20 illustrates the printer 401 with the transfer unit 40 independently removed from the device main body 401A. FIG. 21 illustrates the printer 401 with the transfer unit 440 and the tray unit 50 removed from the device main body 401A. The opening 401A1 is provided on the first end 1b1 side of the device main body 401A. The tray unit 50 and the transfer unit 440 are configured to be removable from the device main body 401A through the opening 401A1. The door 420 is movable between a closed position that covers the opening 401A1 and an open position that exposes the opening 401A1. The door 420 in the open position supports the transfer unit 440 and the tray unit 50 removed to the outside of the device main body 401A by a support portion (not shown). Also in the second embodiment, the fixing device 80 is configured to be movable between a fixing position and a retracted position, and is retracted from the movement space (movement path) of the tray unit 50 when the tray unit 50 is removed.

[0176] [Image formation operation] Next, a description will be given of an image forming operation of the printer 401 according to the second embodiment. In the second embodiment, the moving path of the sheet S and the method of transferring the toner image onto the sheet S are different from those in the first embodiment.

[0177] In the image forming operation, a toner image is formed on the photosensitive drum 61 based on image information, as in the first embodiment. Meanwhile, a sheet S fed from a sheet feeding unit 430 is conveyed along the belt 441 while being sandwiched between a primary transfer roller 442 and the photosensitive drum 61 via the belt 441. At this time, a transfer voltage is applied to the primary transfer roller 442, and the toner image is transferred from the photosensitive drum 61 to the sheet S. In the second embodiment, the movement direction of the belt 441 and the rotation directions of the drive roller 446 and the tension roller 447 during the image forming operation are opposite to those in the first embodiment.

[0178] The sheet S onto which the toner image has been transferred is conveyed toward the fixing device 80, where the toner image is fixed onto the sheet S.

[0179] When single-sided printing is performed, the sheet S that has passed through the fixing device 80 is discharged by the flapper 5 onto a discharge tray 401f formed at the top of the apparatus main body 401A. When double-sided printing is performed, the sheet S that has been inverted by the flapper 5 passes from the double-sided conveying path 420a inside the door 420 through a return conveying path provided above the sheet feeding unit 430, and is then handed over to the belt 441 again. The sheet S is then conveyed again by the belt 441 to a position where it abuts against the photosensitive drum 61. After the toner image is transferred from the photosensitive drum 61 to the rear surface of the sheet S, the sheet S passes through the fixing device 80 and is discharged onto the discharge tray 401f.

[0180] In this way, in the printer 401 according to the second embodiment, a secondary transfer portion is not formed, and toner images of different colors are directly transferred onto the sheet S from the multiple photosensitive drums 61 in an overlapping manner.

[0181] The transfer unit 440 of the second embodiment is configured similarly to the transfer unit 40 of the first embodiment, except that the transfer unit 440 transports the sheet S between the primary transfer roller 442 and the photosensitive drum 61. Specifically, the transfer unit 440 is configured to be removable from the first end 1b1 side of the apparatus main body 401A. Therefore, the user can easily remove jams, access the fixing device 80, install and remove the transfer unit 440 and the tray unit 50, Sheets S can be replenished from the first end 1b1 side of the printer 401.

[0182] Furthermore, the transfer unit 440 is configured to be able to be pulled out from the apparatus main body 401A together with the tray unit 50, and also to be able to be pulled out from the apparatus main body 401A independently of the tray unit 50. When the transfer unit 440 is pulled out together with the tray unit 50, the transfer shaft of the transfer unit 440 passes through the upper guide area 93, which is the first passage of the main guide 90. When the transfer unit 440 is pulled out independently of the tray unit 50, the transfer shaft of the transfer unit 440 passes through the second area 93B of the lower guide area 92, which is the second passage of the main guide 90.

[0183] Furthermore, the tray unit 50 is restricted from being pulled out independently from the device main body 401A by the restricting structure 70. On the other hand, the transfer unit 440 is able to move independently between the inside and outside of the device main body 401A without being restricted by the restricting structure 70.

[0184] Example 3 Next, a third embodiment of the present invention will be described with reference to Figures 22, 23, 24, 25, 26, and 27. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and their description will be omitted, and the description will focus mainly on the characteristic parts of the third embodiment.

[0185] [Configuration of image forming device] 22 is a diagram illustrating the overall configuration of a printer 301 as an image forming apparatus according to Example 3. The printer 301 as an image forming apparatus according to Example 3 includes a device body 301A in which an opening 301A1 is formed, and a door 320. The printer 301 corresponds to the printer 1 of Example 1, the device body 301A corresponds to the device body 1A of Example 1, and the opening 301A1 corresponds to the opening 1A1 of Example 1.

[0186] In the first embodiment, the tray unit 50 and the transfer unit 40 are mounted in the apparatus main body 1A so that their longitudinal directions are inclined relative to the horizontal direction. On the other hand, in the third embodiment, the tray unit 50 and the transfer unit 40 are mounted in the apparatus main body 1A so that their longitudinal directions are parallel to the horizontal direction.

[0187] Figure 23 is a diagram showing the printer 301 in a state where the transfer unit 40 is pulled out alone from the device main body 301A. Figure 24 is a diagram showing the printer 301 in a state where the transfer unit 40 and the tray unit 50 are pulled out from the device main body 301A. The opening 301A1 is provided on the first end 1b1 side of the device main body 301A.

[0188] The tray unit 50 and the transfer unit 40 are configured to be removable from the apparatus main body 301A through the opening 301A1. The door 420 is movable between a closed position that covers the opening 301A1 and an open position that exposes the opening 301A1. The door 320 in the open position supports the transfer unit 340 and the tray unit 50 that have been removed to the outside of the apparatus main body 301A by a support portion (not shown). Also in the third embodiment, the fixing device 80 is configured to be movable between a fixing position and a retracted position, and is retracted from the movement space (movement path) of the tray unit 50 when the tray unit 50 is removed.

[0189] [Transfer unit movement path] Next, the movement path of the transfer unit 40 will be described in more detail with reference to Figures 25, 26, and 27. In the third embodiment, the tray unit 50 and the transfer unit 40 are pulled out horizontally from the device main body 301A. That is, the tray unit 50 and the transfer unit 40 move horizontally between the inside and outside of the device main body 301A without changing their posture.

[0190] 23 and 24, a main guide 900 is attached to the main frame 100. Fig. 25 is a diagram illustrating the configuration of the main guide 900. The configuration of the main guide 900 according to the third embodiment is generally similar to that of the main guide 90 according to the first embodiment, with the curved surface portion 96 removed, and therefore a detailed description thereof will be omitted.

[0191] (Path of movement when the transfer unit moves independently from the tray unit) First, a detailed description will be given of the movement path of the transfer unit 40 when the transfer unit 40 moves independently of the tray unit 50. Figure 26 is a diagram illustrating the movement path of the transfer unit 40, and the path (trajectory) of the transfer shaft 49 when the transfer unit 40 moves independently of the tray unit 50 from the second inner position to the second outer position is shown by a broken line.

[0192] When the transfer unit 40 is located at the second inner position, the transfer shaft 49 is located within the first region 93A of the upper guide region 93. When the transfer unit 40 moves independently from the second inner position to the second outer position, the transfer shaft 49 passes through the first region 93A of the upper guide region 93 of the main guide 90, the notch 91A, and the inclined surface 92A, as shown in FIG. 26 , and enters the lower guide region 92. The transfer unit 40 then moves in the second removal direction Dd2 while being guided by the main guide 90 so that the transfer shaft 49 passes through the lower guide region 92. After the transfer shaft 49 moves until it abuts against the detent portion 92B, the transfer unit 40 can be lifted up, whereupon the transfer shaft 49 passes through the notch 91B, allowing the transfer unit 40 to be removed from the apparatus main body 1A. The second outer position of the transfer unit 40 is the position where the transfer shaft 49 abuts against the detent portion 92B.

[0193] When the transfer unit 40 is moved to the second inner position with the tray unit 50 attached to the apparatus main body 1A, the transfer unit 40 follows the above-mentioned movement trajectory in the opposite direction. That is, the transfer shaft 49 enters the lower guide area 92 from the cutout portion 91B, moves through the lower guide area 92 in its extension direction, climbs the inclined surface 92a, and reaches the first area 93A of the upper guide area 93.

[0194] As described above, when the transfer unit 40 moves independently of the tray unit 50, the transfer shaft 49 passes through the lower guide area 92. Therefore, the transfer unit 40 moves in the second removal direction Dd2 or the second attachment direction Da2 at a position spaced downward from the tray unit 50. With this configuration, the transfer unit 40 can move smoothly between the second inner position and the second outer position without damaging the photosensitive drum 61.

[0195] (Path of movement when the transfer unit moves together with the tray unit) Next, a detailed description will be given of the movement path of the transfer unit 40 when the transfer unit 40 moves together with the tray unit 50. Figure 27 is a diagram illustrating the movement path of the transfer unit 40, and the path (trajectory) of the transfer shaft 49 when the transfer unit 40 moves together with the tray unit 50 from the second inside position to the outside of the apparatus main body 1A is shown by a broken line.

[0196] When the tray unit 50 moves from the first inner position to the first outer position while connected to the transfer unit 40, the lower surface of the tray unit 50 is supported by the tray unit support portion 94. Meanwhile, the transfer unit 40 moves together with the tray unit 50 while being supported from below by the transfer connecting portion 51A of the tray unit 50. Therefore, when the transfer unit 40 moves together with the tray unit 50, the transfer shaft 49 does not fall into the lower guide region 92, but enters the second region 93B and moves along the upper guide region 93.

[0197] A rotatable roller 94A is provided at the end of the tray unit support portion 94 on the second removal direction Dd2 side. The tray unit 50 can move smoothly on the roller 94A. This reduces the load on the user when pulling out the tray unit 50.

[0198] When the center of gravity of the tray unit 50 and the transfer unit 40 is downstream of the rotating roller 94A in the second mounting direction Da2, the tray unit 50 moves while being supported by the tray unit support portion 94. At this time, the tray unit 50 moves while being supported by the rotating roller 94A and a surface 94B downstream of the rotating roller 94A in the second mounting direction Da2.

[0199] When the centers of gravity of the tray unit 50 and the transfer unit 40 are downstream of the rollers 94A in the second removal direction Dd2, the lower surface 51D of the tray unit 50 moves away from the surface 94B of the tray unit support portion 94, and the tray unit 50 moves while being supported by the rollers 94A. The transfer shaft 49 comes into contact with the flat portion 95, which is the upper surface of the second region 93B of the upper guide region 93, thereby limiting the tilt of the tray unit 50 and the transfer unit 40 during movement.

[0200] When the tray unit 50 and the transfer unit 40 are further pulled out from the state in which the transfer shaft 49 is positioned in the second region 93B, the transfer unit 40 is supported by the support portion of the door 20, and the tray unit 50 is supported by the door 20 via the transfer unit 40.

[0201] As described above, when the transfer unit 40 moves together with the tray unit 50, the transfer shaft 49 passes through the upper guide area 93, allowing the tray unit 50 to move smoothly between the first inner position and the first outer position.

[0202] The configurations shown in the above-described embodiments can be combined as needed.

[0203] The disclosure of this embodiment includes the following configuration. (Configuration 1) a device body having an opening; a first unit attached to the device body so as to be removable from the device body through the opening; a second unit attached to the device body so as to be removable from the device body through the opening, the second unit having an engaged portion and configured so as to be removable from the device body together with the first unit and so as to be removable from the device body independently of the first unit; an engaging member that engages with the engaged portion when the second unit is pulled out from the device main body, the engaging member having a first passage and a second passage branched from the first passage; Equipped with When the second unit is pulled out together with the first unit, the engaged portion passes through the first passage, and when the second unit is pulled out independently from the first unit, the engaged portion passes through the second passage. An image forming apparatus characterized by: (Configuration 2) the first passage and the second passage are grooves; 2. The image forming apparatus according to claim 1, wherein the engaged portion is a protrusion that fits into the groove. (Configuration 3) 3. The image forming apparatus according to claim 1, wherein the second passage is farther from the first unit inside the apparatus body than the first passage. (Configuration 4) When the second unit is pulled out independently from the first unit, the engaged portion 4. The image forming apparatus according to any one of configurations 1 to 3, further comprising a restricting portion that restricts the entry of the toner into the first passage. (Configuration 5) the engaging member has a partition portion that separates the first passage and the second passage, and a connecting portion that connects the first passage and the second passage, the second unit has an abutment portion that abuts against the limiting portion when the second unit is pulled out independently from the first unit, The image forming apparatus of configuration 4, characterized in that when the abutting portion abuts against the limiting portion, the position of the engaged portion overlaps the position of the connecting portion in the direction in which the second unit is pulled out to the outside of the apparatus main body. (Configuration 6) The image forming apparatus described in configuration 5, wherein the limiting portion has an inclined surface against which the abutting portion abuts, and the inclined surface guides the abutting portion so that the engaged portion approaches the second passage as the second unit is pulled out to the outside of the apparatus main body. (Configuration 7) The image forming apparatus according to configuration 5 or 6, further comprising a restricting structure that restricts the first unit from being pulled out to the outside of the apparatus body when the abutting portion is in contact with the restricting portion. (Configuration 8) The image forming apparatus according to any one of configurations 1 to 7, wherein a limiting portion is provided that limits the engaged portion from passing through the first passage and reaching a position where the second unit is attached to the apparatus body when the second unit is inserted inside the apparatus body while the first unit is attached to the apparatus body. (Configuration 9) The image forming apparatus according to any one of configurations 1 to 8, wherein the second unit is pulled out to a first position when pulled out together with the first unit, and is pulled out to a second position when pulled out independently from the first unit. (Configuration 10) 10. The image forming apparatus according to configuration 9, wherein the second unit is detachable from the apparatus body when in the second position. (Configuration 11) 11. The image forming apparatus according to configuration 9 or 10, wherein the second position is closer to the apparatus body than the first position. (Configuration 12) the device body has an opening / closing member configured to be able to open and close the opening, 12. The image forming apparatus according to any one of configurations 1 to 11, wherein the opening / closing member supports the second unit pulled out from the apparatus main body when the opening / closing member is in an open state. (Configuration 13) The image forming apparatus according to any one of configurations 1 to 12, characterized in that a portion of the second unit is located inside a space through which the first unit attached to the apparatus main body passes when pulled out. (Configuration 14) The image forming apparatus according to any one of configurations 1 to 13, wherein the first unit is an image forming unit having at least one photosensitive member, and the second unit is a belt unit including a belt that contacts the photosensitive member. (Configuration 15) 15. The image forming apparatus according to configuration 14, wherein the image forming unit has a cartridge including a developing roller that contacts the photosensitive member, and a tray that detachably holds the cartridge. (Configuration 16) a transfer roller that forms a transfer nip with the belt to transfer the image transferred from the photosensitive member to the belt onto a recording material; a feeding section that feeds a recording material to the transfer nip; a fixing device that heats the image transferred at the transfer nip to fix the image onto the recording material; a conveying section that conveys the recording material from the feeding section to the fixing device via the transfer nip, The image forming apparatus of configuration 14 or 15, characterized in that the recording material transported from the feeding section to the fixing device passes through a space through which the first unit passes when it is pulled out from the state in which it is attached to the apparatus main body, and a space through which the second unit passes when it is pulled out from the state in which it is attached to the apparatus main body. (Configuration 17) a fixing device that heats the image transferred onto the recording material to fix the image onto the recording material; The image forming apparatus according to any one of configurations 1 to 16, wherein the fixing device is configured to be movable between a fixing position where an image is fixed to a recording material, the fixing position overlapping a space through which the first unit passes when pulled out from the apparatus main body, and a retracted position where the fixing device retracts from the space. (Configuration 18) a paper feed cassette that stores recording materials and is configured to be removable from the device body; An image forming apparatus according to any one of configurations 1 to 17, characterized in that, when viewed vertically, the direction in which the paper feed cassette is pulled out is the same as the direction in which the first unit is pulled out from the apparatus main body. [Explanation of symbols]

[0204] 1... printer (image forming apparatus), 1A... apparatus main body, 1A1... opening, 40... transfer unit (second unit), 49... transfer shaft (engaged portion), 50... tray unit (first unit), 90... main guide (engaging member), 92... lower guide area (second passage), 93... upper guide area (first passage)

Claims

1. a device body having an opening; a first unit attached to the device body so as to be removable from the device body through the opening; a second unit attached to the device body so as to be removable from the device body through the opening, the second unit having an engaged portion and configured so as to be removable from the device body together with the first unit and so as to be removable from the device body independently of the first unit; an engaging member that engages with the engaged portion when the second unit is pulled out from the device main body, the engaging member having a first passage and a second passage branched from the first passage; Equipped with When the second unit is pulled out together with the first unit, the engaged portion passes through the first passage, and when the second unit is pulled out independently from the first unit, the engaged portion passes through the second passage. An image forming apparatus characterized by:

2. the first passage and the second passage are grooves; 2. The image forming apparatus according to claim 1, wherein the engagement portion is a protrusion that fits into the groove.

3. 2. The image forming apparatus according to claim 1, wherein the second passage is farther from the first unit inside the apparatus main body than the first passage.

4. 2. The image forming apparatus according to claim 1, further comprising a restricting portion that restricts the engagement portion from entering the first passage when the second unit is pulled out independently of the first unit.

5. the engaging member has a partition portion that separates the first passage and the second passage, and a connecting portion that connects the first passage and the second passage, the second unit has an abutment portion that abuts against the limiting portion when the second unit is pulled out independently from the first unit, 5. The image forming apparatus according to claim 4, wherein when the abutting portion abuts against the limiting portion, the position of the engaged portion overlaps the position of the connecting portion in the direction in which the second unit is pulled out to the outside of the apparatus main body.

6. The image forming apparatus according to claim 5, wherein the limiting portion has an inclined surface against which the abutting portion abuts, and the inclined surface guides the abutting portion so that the engaged portion approaches the second passage as the second unit is pulled out to the outside of the apparatus main body.

7. 6. The image forming apparatus according to claim 5, further comprising a restricting structure that restricts the first unit from being pulled out to the outside of the apparatus body when the contact portion is in contact with the restricting portion.

8. 2. The image forming apparatus according to claim 1, further comprising a limiting portion that, when the first unit is attached to the device body and the second unit is inserted inside the device body, limits the engaged portion from passing through the first passage and reaching a position where the second unit is attached to the device body.

9. 2. The image forming apparatus according to claim 1, wherein the second unit is pulled out to a first position when pulled out together with the first unit, and is pulled out to a second position when pulled out independently of the first unit.

10. 10. The image forming apparatus according to claim 9, wherein the second unit is detachable from the main body of the apparatus when in the second position.

11. 10. The image forming apparatus according to claim 9, wherein the second position is closer to the apparatus body than the first position.

12. the device body has an opening / closing member configured to be able to open and close the opening, 2. The image forming apparatus according to claim 1, wherein the opening / closing member supports the second unit drawn out from the main body of the apparatus when the opening / closing member is in an open state.

13. 2. The image forming apparatus according to claim 1, wherein a part of the second unit is located inside a space through which the first unit attached to the apparatus main body passes when it is pulled out.

14. The image forming apparatus according to any one of claims 1 to 13, wherein the first unit is an image forming unit having at least one photosensitive member, and the second unit is a belt unit including a belt that contacts the photosensitive member.

15. 15. The image forming apparatus according to claim 14, wherein the image forming unit comprises a cartridge including a developing roller that contacts the photosensitive member, and a tray that detachably holds the cartridge.

16. a transfer roller that forms a transfer nip with the belt to transfer the image transferred from the photosensitive member to the belt onto a recording material; a feeding section that feeds a recording material to the transfer nip; a fixing device that heats the image transferred at the transfer nip to fix the image onto the recording material; a conveying section that conveys the recording material from the feeding section to the fixing device via the transfer nip, 15. The image forming apparatus according to claim 14, wherein the recording material transported from the feeding section to the fixing device passes through a space through which the first unit passes when it is pulled out from the state in which it is attached to the device main body, and a space through which the second unit passes when it is pulled out from the state in which it is attached to the device main body.

17. a fixing device that heats the image transferred onto the recording material to fix the image onto the recording material; The image forming apparatus according to any one of claims 1 to 13, characterized in that the fixing device is configured to be movable between a fixing position where an image is fixed to a recording material, overlapping a space through which the first unit passes when pulled out from a state where it is attached to the apparatus main body, and a retracted position where it retracts from the space.

18. a paper feed cassette that stores recording materials and is configured to be removable from the device body; An image forming apparatus according to any one of claims 1 to 13, characterized in that, when viewed vertically, the direction in which the paper feed cassette is pulled out is the same as the direction in which the first unit is pulled out from the apparatus main body.

Images