Image forming apparatus

Abstract

An image forming apparatus includes a positioning portion, a restricting portion, and a returning portion. An engaged portion is provided on the other one of the device body and the pull-out portion as compared to an engaging portion provided on the other one of the device body and the pull-out portion. When the pull-out portion is in the attached position, the first contact portion and the second contact portion are in contact with the engagement portion. Contact between the first contact portion and the engagement portion restricts movement of the pull-out portion in an insertion direction. Contact between the second contact portion and the engagement portion restricts movement of the pull-out portion in a pull-out direction. The restricting portion restricts movement of the pull-out portion when the pull-out portion reaches a restricted position. The return portion moves the pull-out portion to the attachment position when the pull-out portion is in the restricted position.

Description

Technical Field

[0001] This disclosure relates to a positioning device for positioning a pull-out portion relative to the main body of a device, and to an image forming apparatus including the positioning device. Background Technology

[0002] Some image forming apparatuses, such as printers, copiers, and multifunction peripherals, are configured to detachably mount a cartridge on a tray (pull-out portion) that moves between the interior and exterior of the apparatus body. The cartridge is formed by integrally incorporating a photosensitive drum and a processing unit acting on the photosensitive drum. Conventionally, an image forming apparatus has been proposed in which an engaging portion is disposed on one of the apparatus body and the tray, while a portion to be engaged is disposed on the other of the apparatus body and the tray, and wherein the engagement between the engaging portion and the portion to be engaged allows the tray to be positioned in the attachment direction.

[0003] When at least one of the joining part and the joined part deforms, the position of the pallet relative to the main body of the equipment changes. Summary of the Invention

[0004] This disclosure aims to provide a technique that can suppress the effect on the positioning of a pallet relative to the equipment body caused by deformation of at least one of the joining and joined portions.

[0005] To solve the above problems, the image forming apparatus according to this disclosure, configured to perform an image forming operation on a recording material, includes:

[0006] Equipment body;

[0007] The pull-out portion is movable relative to the device body in the insertion direction and in the pull-out direction opposite to the insertion direction. The pull-out portion is movable relative to the device body to an attachment position, a pull-out position downstream of the attachment position in the pull-out direction, and a restricted position downstream of the attachment position in the insertion direction.

[0008] The engaging portion is disposed on one of the device body and the pull-out portion; and

[0009] The joined portion is disposed on the other of the device body and the pull-out portion.

[0010] in

[0011] The joined parts include:

[0012] The positioning portion includes a first contact portion and a second contact portion. When the pull-out portion is in the attachment position, the first and second contact portions of the positioning portion contact the engagement portion. The movement of the pull-out portion in the insertion direction is limited by the contact between the first contact portion and the engagement portion, and the movement of the pull-out portion in the pull-out direction is limited by the contact between the second contact portion and the engagement portion.

[0013] A limiting portion, configured to contact the engaging portion when the pull-out portion reaches the limited position, to limit the movement of the pull-out portion in the insertion direction, and

[0014] The return portion is configured to contact the engagement portion when the pull-out portion is in the restricted position, such that the pull-out portion moves from the restricted position to the attachment position under its own weight.

[0015] The features of this disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings. The following description of the embodiments is by way of example. Attached Figure Description

[0016] Figure 1 This is a diagram showing the overall configuration of the image forming apparatus according to the first embodiment;

[0017] Figure 2 This is a diagram showing an image forming device in which a door is open;

[0018] Figure 3 This is a diagram showing an image forming apparatus in which the fixing device has been moved;

[0019] Figure 4 This is a diagram showing an image forming apparatus in which the transfer unit and tray unit have been pulled out;

[0020] Figure 5 This is a diagram showing an image forming apparatus in which the transfer unit has been pulled out individually;

[0021] Figure 6 This is a diagram illustrating the movement of the transfer unit and the tray unit according to the first embodiment;

[0022] Figure 7 This is a diagram illustrating the movement of the transfer unit and the tray unit according to the first embodiment;

[0023] Figure 8 This is a diagram showing the connecting members of the connecting tray and the transfer unit according to the first embodiment;

[0024] Figure 9 This is a diagram showing the connecting members of the connecting tray and the transfer unit according to the first embodiment;

[0025] Figure 10A This is a diagram showing the state in which the first contact portion and the second contact portion are in contact with the connecting shaft when positioning the tray unit and the device body according to the first embodiment;

[0026] Figure 10B This is a diagram showing the state in which the third contact portion contacts the connecting shaft when positioning the tray unit and the device body according to the first embodiment;

[0027] Figure 11 This is a diagram showing the positioning of the tray unit and the device body according to the first embodiment;

[0028] Figure 12 This is a cross-sectional view of the upper surface of the main body of the equipment;

[0029] Figure 13 This is a diagram showing the tray handle of the tray unit according to the second embodiment;

[0030] Figure 14A This is a diagram showing the state in which the tray shaft contacts both the first contact portion and the second contact portion when positioning the tray unit and the device body according to the second embodiment;

[0031] Figure 14B This is a diagram showing the state in which the tray shaft contacts the third contact portion when positioning the tray unit and the device body according to the second embodiment;

[0032] Figure 15 This is a diagram showing the positioning of the tray unit and the device body according to the second embodiment;

[0033] Figure 16 This is a diagram showing the positioning of the tray unit and the device body according to the third embodiment;

[0034] Figure 17 This is a diagram showing the positioning of the tray unit and the device body according to the fourth embodiment;

[0035] Figure 18A This is a diagram showing a state in which a third contact portion disposed on a tray unit contacts a connecting shaft disposed on a device body in a configuration of a joining portion and a joined portion according to the first embodiment, wherein the tray unit is in a restricted position.

[0036] Figure 18B The diagram shows a configuration of the joining portion and the joined portion according to the first embodiment, in which a first contact portion and a second contact portion disposed on the tray unit are in contact with a connecting shaft disposed on the device body, and wherein the tray unit is in an attached position.

[0037] Figure 19AThe diagram illustrates a configuration of the engaging and engaged portions according to the second embodiment, where a tray shaft disposed on the tray unit contacts a third contact portion disposed on the device body, and the tray unit is in a restricted position; and

[0038] Figure 19B The diagram shows a state in which a tray shaft disposed on the device body contacts a first contact portion and a second contact portion disposed on a tray unit in a configuration of a joining portion and a joined portion according to the second embodiment, wherein the tray unit is in an attached position. Detailed Implementation

[0039] Hereinafter, with reference to the accompanying drawings, exemplary embodiments for implementing the present disclosure will be described in detail. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described in the embodiments may be appropriately modified according to the configuration of the device to which the present disclosure is applied and various conditions. That is, the scope of the present disclosure is not intended to be limited to the following embodiments. Furthermore, all features described in the following embodiments are not necessarily necessary for the disclosed solutions.

[0040] First Embodiment

[0041] Overall Configuration

[0042] refer to Figure 1 The printer 1, which is used as an image forming device, will be described. Figure 1 This is a diagram showing the overall configuration of printer 1 according to this embodiment. In this embodiment, printer 1 is an electrophotographic color laser beam printer that forms images on a sheet S used as recording material.

[0043] Printer 1 has a main body (housing) 1A, a scanner (exposure device) 2, a control unit 3, and a door (opening and closing member) 20 that can be opened and closed relative to the main body 1A. Furthermore, printer 1 also has a sheet feed unit 30, a transfer unit (transfer device) 40, a tray unit (moving unit or support unit) 50, and a fixing unit 80. The portion including the main body 1A and the door 20 can also be referred to as the main frame 100. The main frame 100 includes the external portion of printer 1.

[0044] The main body 1A of the device houses a scanner 2, a control unit 3, a sheet feed section 30, a transfer unit 40, a tray unit 50, and a fixing unit 80. The sheet feed section 30 has a sheet stacking tray 31 for stacking sheets S used as recording materials, and a supply roller 32. The sheet stacking tray 31 can be pulled out toward the door 20 to replenish the sheets S. The tray unit 50 has a tray (support member or drawer) 51 and boxes PY, PM, PC, and PK. The tray 51 has a tray handle 52. Boxes PY, PM, PC, and PK are attached so that they can be removed from the tray 51.

[0045] Each of cartridges PY, PM, PC, and PK can be independently attached to and detached from tray 51. Cartridges PY, PM, PC, and PK contain yellow (Y), magenta (M), cyan (C), and black (K) toners (developers), respectively. Cartridges PY, PM, PC, and PK have the same configuration except that they contain different colors of toner. Therefore, the configuration and operation of one of cartridges PY, PM, PC, and PK will be described, and descriptions of the other cartridges may be omitted. Furthermore, when cartridges PY, PM, PC, and PK need not be distinguished from each other, they can be simply referred to as cartridge P. It can be said that tray unit 50 has multiple cartridges P and tray 51, with cartridges P attached to the tray in a manner that makes them removable.

[0046] In this embodiment, the tray unit 50 has multiple photosensitive drums (image carriers) 61, multiple charging rollers (charging components) 62, 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 71. The rotation axes of the photosensitive drums 61, developing rollers 71, and charging rollers 62 are parallel to each other.

[0047] The portion forming the black (K) image is referred to as the black station (first station). The photosensitive drum 61 of the first station is called the first photosensitive drum, its developing roller 71 is called the first developing roller, and its charging roller 62 is called the first charging roller. The portion forming the cyan (C) image is referred to as the cyan station (second station). The photosensitive drum 61 of the second station is called the second photosensitive drum, its developing roller 71 is called the second developing roller, and its charging roller 62 is called the second charging roller. The portion forming the magenta (M) image is referred to as the magenta station (third station). The photosensitive drum 61 of the third station is called the third photosensitive drum, its developing roller 71 is called the third developing roller, and its charging roller 62 is called the third charging roller. The portion forming the yellow (Y) image is referred to as the yellow station (fourth station). The photosensitive drum 61 of the fourth station is called the fourth photosensitive drum, its developing roller 71 is called the fourth developing roller, and its charging roller 62 is called the fourth charging roller. Boxes PK, PC, PM, and PY are attached to the black station, cyan station, magenta station, and yellow station, respectively. In this embodiment, boxes PK, PC, PM, and PY are referred to as the first box, the second box, the third box, and the fourth box, respectively.

[0048] Please note that numbers such as "first", "second", "third" and "fourth" are used merely for ease of explanation.

[0049] The photosensitive drum 61, charging roller 62, and developing roller 71 can be disposed in the cartridge P or on the tray 51. In this embodiment, the cartridge P has a corresponding photosensitive drum 61, charging roller 62, and developing roller 71.

[0050] The transfer unit 40 includes a belt 41, a primary transfer roller 42, a cleaning section 43, a drive roller 46 for driving the belt 41, and a tension roller (driven roller) 47. In the printer 1 according to this embodiment, an optical sensor 44 is arranged to detect the toner image transferred onto the belt 41. In this embodiment, the belt 41 is arranged below and in contact with the photosensitive drum 61, forming a primary transfer portion between the belt 41 and the photosensitive drum 61. Furthermore, the printer 1 has a secondary transfer roller 45 that contacts the belt 41, forming a secondary transfer portion. The secondary transfer portion is formed between the belt 41 and the secondary transfer roller 45. The rotation axes of the primary transfer roller 42, the drive roller 46, the tension roller 47, and the secondary transfer roller 45 are parallel to each other. A pair of alignment rollers 4 are arranged upstream of the secondary transfer portion.

[0051] The fixing device 80 includes a fixing section 81 and a baffle 5. When an image forming operation is performed on the sheet S, the fixing device 80 is in the use position. In the use position, the fixing device 80 is housed within the device body 1A (inside). Furthermore, in the use position, the fixing device 80 is configured to heat the sheet S. In this embodiment, the fixing section 81 includes a heating section (heating roller) 82 containing a heater and a pressure section (pressure roller) 83.

[0052] refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The movement of the transfer unit 40 and the tray unit 50 will be described. Figure 2 This is a diagram showing printer 1 with door 20 open. Figure 3 This is a diagram showing printer 1 with the fixing device 80 in a moved state. Figure 4 This is a diagram showing printer 1 with the transfer unit 40 and tray unit 50 pulled out. Figure 5 This is a diagram showing printer 1 with the transfer unit 40 pulled out separately.

[0053] The transfer unit 40 and the tray unit 50 are movable from the interior to the exterior of the device body 1A. In the horizontal direction H, the device body 1A has a first end 1b1 with an opening 1A1 and a second end 1b2 opposite to the first end 1b1. The tray unit 50 is movable through the opening 1A1 between a first interior position inside the device body 1A and a first exterior position outside the device body 1A. The transfer unit 40 is movable through the opening 1A1 between a second interior position inside the device body 1A and a second exterior position outside the device body 1A. The opening 1A1 may include an opening through which the tray unit 50 passes and an opening through which the transfer unit 40 passes. When the transfer unit 40 moves from the second interior position to the second exterior position, at least the belt 41 moves, wherein at least a portion of the belt protrudes outward from the device body 1A.

[0054] The direction in which the pallet unit 50 moves from the first inner position to the first outer position is called the pallet pull-out direction Dd1 (pull-out direction), and the direction opposite to the pallet pull-out direction Dd1 is called the pallet attachment direction Da1 (attachment direction). It can be said that the pallet pull-out direction Dd1 is the direction from the second end 1b2 toward the first end 1b1.

[0055] The direction in which the transfer unit 40 moves from the second inner position to the second outer position is called the transfer pull-out direction Dd2, and the direction opposite to the transfer pull-out direction Dd2 is called the transfer attachment direction Da2. In the transfer pull-out direction Dd2, the drive roller 46 is located downstream of the tension roller 47. The transfer pull-out direction Dd2 is the direction from the second end 1b2 toward the first end 1b1.

[0056] The tray pull-out direction Dd1 and the tray attachment direction Da1 are directions that intersect the rotation axis of the photosensitive drum 61 (these can be orthogonal directions). The transfer pull-out direction Dd2 and the transfer attachment direction Da2 are directions that intersect the rotation axis of the drive roller 46 (these can be orthogonal directions). The rotation axis of the drive roller 46 is parallel to the rotation axis of the photosensitive drum 61.

[0057] In the horizontal direction H, the fixing device 80 is arranged on one end side of the equipment body 1A (i.e., the side on which the first end 1b1 is arranged).

[0058] The door 20 attached to the main body of the equipment 1A can move between a closed position and an open position. For example... Figure 1 As shown, when door 20 is in the closed position (closed state), the door covers opening 1A1. (As indicated...) Figure 2 As shown, when the door 20 is in the open position (open state), the opening 1A1 is exposed.

[0059] like Figure 1As shown, when the door 20 is in the closed position, it covers the fixing device 80 attached to the main body 1A of the device. 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. The upper cover portion 20b of the door 20 serves as part of the outer portion.

[0060] When the fixing unit 80 is supported by the equipment body 1A, the door 20 can move between an open position and a closed position. In other words, the door 20 moves from the closed position to the open position to separate from the fixing unit supported by the equipment body 1A. Therefore, as Figure 2 As shown, when the door 20 is in the open position, the door is separated from the fixing device 80 supported by the main body 1A of the equipment.

[0061] As will be described later, the fixing device 80 is able to... Figure 2 The state shown moves to Figure 3 The state shown exposes opening 1A1 extensively. This is because door 20 and fixing device 80 have already been moved ( Figure 3 In this state, the transfer unit 40 and the tray unit 50 can move from the inside to the outside of the device body 1A through the opening 1A1. After moving, they obtain... Figure 4 The state shown.

[0062] With the tray unit 50 already moved outside the main body 1A of the device ( Figure 4 This allows for the removal of cartridges PY, PM, PC, and PK from tray 51, and also allows for the attachment of cartridges PY, PM, PC, and PK to tray 51. Therefore, cartridges PY, PM, PC, and PK can be replaced with new cartridges PY, PM, PC, and PK, respectively. In this embodiment, cartridge P can be attached to or removed from tray 51 in a direction intersecting (which can be orthogonal) to the axis of rotation of the photosensitive drum 61.

[0063] Boxes PY, PM, PC, and PK are removed from tray 51 by moving relative to tray 51 in a direction away from transfer unit 40. In other words, boxes PY, PM, PC, and PK are removed from tray 51 by moving relative to tray 51 to the side opposite to transfer unit 40. In this embodiment, transfer unit 40 is arranged below tray unit 50. Therefore, boxes PY, PM, PC, and PK are removed from tray 51 by moving upward relative to tray 51.

[0064] Furthermore, the transfer unit 40 can be removed from the main body 1A of the device independently of the tray unit 50, and can be replaced with a new transfer unit 40.

[0065] Image forming operations

[0066] refer to Figure 1The image forming operation of printer 1 will be described. The control unit 3 of printer 1 initiates an image forming operation on 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, a fax machine, etc.

[0067] When an image is formed on the sheet S, the fixing device 80 is in the use position, the tray unit 50 is in the first internal position, the transfer unit 40 is in the second internal position, and the door 20 is in the closed position. When the transfer unit 40 is in the second internal position, the belt 41 can contact the photosensitive drum 61. At this time, the tray unit 50 is located above the transfer unit 40.

[0068] When a charging voltage is applied to the charging roller 62, the photosensitive drum 61 rotates. A laser beam corresponding to the image information is irradiated onto the photosensitive drum 61 from the scanner 2, thereby exposing the surface of the photosensitive drum 61 charged by the charging roller 62. As a result, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum 61.

[0069] The developing roller 71 carries toner. A developing voltage is applied to the developing roller 71, and the electrostatic latent image formed on the photosensitive drum 61 is developed by the toner supplied from the developing roller 71, thereby forming a toner image on the surface of the photosensitive drum 61. In this embodiment, the developing roller 71 develops the electrostatic latent image when in contact with the photosensitive drum 61. However, the developing roller 71 can also develop the electrostatic latent image with a gap between the developing roller 71 and the photosensitive drum 61.

[0070] When forming a panchromatic image, toner images of various colors are formed on each photosensitive drum 61.

[0071] It should be noted that in this embodiment, when the tray unit 50 is in the first internal position, the developing roller 71 can move between a contact position where the developing roller is in contact with the photosensitive drum 61 and a separation position where the developing roller is separated from the photosensitive drum 61. Specifically, a switching device provided in the device body 1A switches between the state where the developing roller 71 is in the contact position and the state where the developing roller 71 is in the separation position. Therefore, when no image forming operation is performed, the developing roller 71 can be separated from the photosensitive drum 61.

[0072] Furthermore, printer 1 can perform monochrome printing when the developing roller 71 and photosensitive drum 61 corresponding to cartridge PK are in contact with each other, while the developing roller 71 and photosensitive drum 61 corresponding to cartridges PY, PM, and PC are separated from each other. Additionally, printer 1 can perform full-color printing when the photosensitive drum 61 corresponding to cartridges PY, PM, PC, and PK are in contact with the belt 41.

[0073] The toner image formed on the corresponding photosensitive drum 61 is transferred from the primary transfer roller 42 to the belt 41 at the primary transfer section, and then conveyed toward the secondary transfer section formed by the belt 41 and the secondary transfer roller 45.

[0074] Simultaneously, a transport channel (first channel or first conveying channel) 1c is formed in the main body 1A of the equipment, through which the sheet S facing the fixing device 80 passes. Furthermore, a double-sided transport channel (second channel or second conveying channel) 20a is formed on the door 20, through which the sheet S that has already passed through the fixing device 80 passes. The door 20 covers the transport channel 1c when closed. When the door 20 is opened, the transport channel 1c and the double-sided transport channel 20a are exposed. Figure 2 ).

[0075] In the sheet feeding section 30, one sheet S of the sheets S stacked in the sheet stacking tray 31 is separated and fed by the supply roller 32 at a specified time, and is conveyed toward the secondary transfer section and the fixing device 80 through the transfer channel 1c.

[0076] In the secondary transfer section, the toner image is transferred from belt 41 to sheet S. Toner not transferred to sheet S is removed from belt 41 by a cleaning scraper (cleaning member) 43A disposed in cleaning section 43.

[0077] In the secondary transfer section, the sheet S onto which the toner image has been transferred is conveyed toward the fixing device 80. In the fixing device 80, the sheet S is heated and pressurized by the fixing section 81, and the toner image is fixed onto the sheet S. The sheet S onto which the toner image has been fixed is then conveyed toward the baffle 5, which serves as a channel switching section.

[0078] The baffle 5 is movable between a sheet discharge position in which the sheet S, which has passed through the fixing device 80, is guided toward the sheet discharge channel 1d, and a reversal position in which the sheet S is guided toward the reversal channel 1e.

[0079] When single-sided printing is performed to form an image on one side of the sheet S, the sheet S is guided by the baffle 5 to the sheet discharge channel 1d and discharged onto the discharge tray 1f formed in the upper part of the equipment body 1A.

[0080] On the other hand, when double-sided printing is performed to form images on both sides of the sheet S, the sheet S is guided by the baffle 5 to the reversing channel 1e. After the sheet S is guided to the reversing channel 1e, the conveying direction of the sheet S is reversed, and the sheet S is conveyed towards the secondary transfer section through the double-sided conveying channel 20a formed on the door 20. After the toner image is transferred to the back side of the sheet S in the secondary transfer section, the sheet S passes through the fixing device 80, is guided by the baffle 5 to the sheet discharge channel 1d, and is discharged onto the discharge tray 1f of the equipment body 1A.

[0081] Arrangement of the tray pull-out unit, transfer unit, and fixing unit

[0082] refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The description will cover the pulling out of the tray unit 50 and the transfer unit 40 from the main body 1A of the equipment and the arrangement of the fixing device 80.

[0083] As described above, the fixing unit 80 of printer 1 is arranged horizontally on one end of the device body 1A. Furthermore, the transfer unit 40 and the tray unit 50 move from one end of the device body 1A to the outside of the device body 1A through the opening 1A1.

[0084] In other words, in the horizontal direction H, the fixing device 80 is positioned closer to the first end 1b1 than the second end 1b2. That is, in the horizontal direction H, the distance between the fixing device 80 and the first end 1b1 is shorter than the distance between the fixing device 80 and the second end 1b2. The fixing device 80 is positioned closer to the first end 1b1 in the horizontal direction H than the center of the device body 1A. It can be said that in the horizontal direction H, the distance between the first end 1b1 and the fixing device 80 is shorter than the distance between the first end 1b1 and the center of the device body 1A.

[0085] As described above, when the tray unit 50 moves from the first inner position to the first outer position, the direction of movement of the tray unit 50 is the direction intersecting the rotation axis of the photosensitive drum 61. At this time, the tray unit 50 moves away from the second end 1b2.

[0086] As described above, when the transfer unit 40 moves from the second inner position to the second outer position, the direction of movement of the transfer unit 40 is the direction intersecting the rotation axis of the drive roller 46. At this time, the transfer unit 40 moves away from the second end 1b2.

[0087] As described above, according to this embodiment, the door 20, in its closed state, covers the opening 1A1 and also covers at least a portion of the transport channel 1c for the sheet S. Furthermore, the door 20 includes a double-sided transport channel 20a. When the sheet S jams (hereinafter referred to as a "paper jam"), the user of the printer 1 can remove the sheet S from one end of the device body 1A to clear the paper jam. Specifically, by moving the door 20 to the open position, the user can access the interior of the device body 1A and remove the sheet S. Furthermore, when a portion of the sheet S that has passed through the fixing device 80 is exposed to the outside of the device body 1A, the user can pull the sheet S out from the outside of the device body 1A and remove the sheet S without opening the door 20.

[0088] Furthermore, by moving the transfer unit 40 and the tray unit 50 from one end of the device body 1A to the outside of the device body 1A, the user of the printer 1 can perform operations such as checking the status, maintenance, or replacing the transfer unit 40 and the tray P.

[0089] In other words, in printer 1, the transfer unit 40 and the tray unit 50 are configured to move between the interior and exterior of the device body 1A via one end side of the device body 1A, while the fixing unit 80 is arranged on one end side of the device body 1A. Therefore, the user can clear paper jams, approach the fixing unit 80, and operate the transfer unit 40 and the tray unit 50 from one direction.

[0090] In this embodiment, the side of the printer 1 with the door 20 is defined as the front side. Therefore, it is only necessary to ensure space for performing operations such as clearing paper jams and operating the transfer unit 40 and tray unit 50 from the front side of the printer 1. On the other hand, it is not necessary to ensure space for performing these operations from the left, right, rear, and top sides of the printer 1. Therefore, the printer 1 can be installed in a smaller space.

[0091] If the transfer unit 40 or the tray unit 50 is pulled out from the other end of the device body 1A, the user needs to approach both ends of the device body 1A to clear the paper jam and pull out the transfer unit 40 or the tray unit 50. Furthermore, if one of the transfer unit 40 or the tray unit 50 is pulled out from one end of the device body 1A and the other is pulled out from the other end, the user needs to approach both ends of the device body 1A. Therefore, it is necessary to ensure space not only for operations performed from the front of the device body 1A but also for operations performed from the rear, which results in an increase in the mounting area of ​​the printer 1.

[0092] Furthermore, in this embodiment, the replenishment of the sheet S can be performed from one end of the device body 1A. Therefore, only space needs to be ensured for replenishing the sheet S from the front of the printer 1, thus allowing the printer 1 to be installed in a smaller space.

[0093] Relationship between tray unit and fixing unit

[0094] refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 6 and Figure 7 The relationship between tray unit 50 and fixing device 80 will be described. Figure 6 and Figure 7 This is a diagram showing the movement of the transfer unit 40 and the tray unit 50.

[0095] During the movement between the first internal position (attached position) where the image forming operation is performed on the sheet S and the first external position (pull-out position) allowing the replacement cartridge P, the tray unit 50 traverses a designated space. As described above, the space traversed by the tray unit 50 during its movement from the first internal position to the first external position is referred to as the first space (the movement space of the tray unit 50). The first space can also be referred to as the channel or track traversed by the tray unit 50 during its movement from the first internal position to the first external position (the first movement channel or the first movement track).

[0096] During the movement between the second inner position and the second outer position on the sheet S where the image forming operation is performed, the transfer unit 40 traverses a designated space. The space traversed by the transfer unit 40 during its movement from the second inner position to the second outer position is called the second space (the movement space of the transfer unit 40). The second space can also be referred to as the channel or track (second movement channel or second movement track) traversed by the transfer unit 40 during its movement from the second inner position to the second outer position.

[0097] When an image forming operation is performed on the sheet S, the position (use position) of the fixing device 80 has the following relationship with the first space and the second space.

[0098] In other words, such as Figure 6 and Figure 7 As shown, at least a portion of the fixing device 80 in the use position overlaps with the first space. In other words, when the fixing device 80 is in the use position, at least a portion of the fixing device 80 is located within the first space.

[0099] In this embodiment, when the tray unit 50 moves from the first inner position to the first outer position, at least a portion of the fixing device 80 overlaps with the space traversed by the cartridge P. However, it can alternatively be arranged to overlap with the space traversed by the tray 51.

[0100] Therefore, compared to the configuration where the fixing device 80 is located outside the first space, the main body of the device 1A is miniaturized.

[0101] It should be noted that in this embodiment, when the door 20 is in the closed state, at least a portion of the double-sided conveyor channel 20a overlaps with the first space, such as... Figure 6 As shown. That is, when the door 20 is closed, at least a portion of the double-sided transmission channel 20a is located in the first space.

[0102] As described above, at least a portion of the fixing device 80 in the use position is located inside the first space. Therefore, when the fixing device 80 is in the use position, the movement of the tray unit 50 from the first internal position to the first external position is restricted. On the other hand, the fixing device 80 is configured to be retractable from the use position. In the retracted state of the fixing device 80, the tray unit 50 is allowed to move from the first internal position to the first external position. When the tray unit 50 moves from the first internal position to the first external position, the tray unit passes under the fixing device 80. It should be noted that the fixing device 80 is located outside the second space in both the use position and the retracted position. Therefore, when the fixing device 80 is in both the use position and the retracted position, the transfer unit 40 is allowed to move from the second internal position to the second external position. When the transfer unit 40 moves from the second internal position to the second external position, the transfer unit passes under the fixing device 80.

[0103] The fixing device 80 has a fixing frame body 80a that supports the fixing part 81. When the fixing device 80 is retracted from the use position, the fixing frame body 80a is displaced relative to the device body 1A, while supporting the fixing part 81.

[0104] When the tray unit 50 is pulled out relative to the main body 1A, the door 20 is first moved to the open position, such as... Figure 2 As shown. In this embodiment, when the fixing device 80 is in the use position, the door 20 is movable between the open position and the closed position. Then, when the door 20 is in the open position, the fixing device 80 moves from the use position to the retracted position so that it is located outside the first space, as shown. Figure 3 As shown.

[0105] In the printer 1 according to this embodiment, the fusing device 80 is movable between a use position and a retracted position while remaining attached to the device body 1A. In this embodiment, when the fusing device is in the retracted position, the entire fusing device 80 is located outside the first space.

[0106] The fixing device 80 is raised from the using position and positioned in a retracted position above the using position. In other words, the retracted position is higher than the using position. Figure 7 As shown, when the fusing unit 80 is in the retracted position, at least a portion of the fusing unit 80 is in a position protruding outward from the main body 1A of the device. Furthermore, when the fusing unit 80 is in the retracted position, at least a portion of the fusing unit 80 is higher than the upper cover portion 20b of the door 20 when it is in the closed position. Therefore, in the vertical direction V, when the fusing unit 80 is in the use position, the size of the printer 1 can be kept relatively small, and when the fusing unit 80 is moved to the retracted position, sufficient space can be ensured for allowing the tray unit 50 to move. It should be noted that when the fusing unit 80 is in the retracted position, movement of the door 20 to the closed position is restricted.

[0107] Specifically, printer 1 has a connecting member (fixed connecting member, fixed link, or arm) 85 that is movably connected to the device body 1A. Fusing unit 80 is connected to device body 1A via connecting member 85.

[0108] The connecting member 85 is rotatable about a rotation center 85A. When the tray unit 50 is pulled out to the outside of the device body 1A, the connecting member 85 moves to the outside of the first space. The fixing device 80 is rotatably connected to one end of the connecting member 85, and the other end of the connecting member 85 is rotatably connected to the device body 1A about the rotation center 85A. The fixing device 80 is movable between a used position and a retracted position while being supported by the connecting member 85 (i.e., while being connected to the device body 1A via the connecting member 85). The connecting member 85 is configured to be movable (swingable) relative to the device body 1A and the fixing device 80. That is, the fixing device 80 is connected to the device body 1A via the connecting member 85. Therefore, compared to a configuration where the fixing device 80 is directly connected to the device body 1A, the amount of movement of the fixing device 80 between the retracted position and the used position can be increased.

[0109] like Figure 7 As shown, when the tray unit 50 moves from the first inner position to the first outer position, the angle formed between the moving direction of the tray unit 50 and the horizontal direction H is smaller than the angle formed between the moving direction of the tray unit 50 and the vertical direction V. Furthermore, when the fixing device 80 moves from the using position to the retracted position, the amount of movement of the fixing device 80 in the vertical direction V is greater than the amount of movement of the fixing device 80 in the horizontal direction H. In other words, when the fixing device 80 moves from the using position to the retracted position, the amount of movement of the fixing device 80 in the direction perpendicular to the moving direction of the tray unit 50 is greater than the amount of movement of the fixing device 80 in the direction parallel to the moving direction of the tray unit 50.

[0110] Furthermore, the fixing device 80 can move between a used position and a retracted position while being held attached to the device body 1A by a guide fixed to the device body 1A. In this case, the guide can have any shape.

[0111] However, the method for moving the fixing device 80 to the outside of the first space is not limited to this. For example, the fixing device 80 can be configured to be removed from the device body 1A so as to retract from the use position. In this way, the fixing device 80 can be moved to the outside of the first space. That is, the fixing device 80 can be located outside the first space by separating it from the device body 1A and the door 20 (i.e., by separating it from the main frame 100). Furthermore, the fixing device 80 can be configured to be connected to the door 20. In this way, the fixing device 80 can be moved to the outside of the first space by opening the door 20.

[0112] Relationship between tray unit and transfer unit

[0113] refer to Figures 1 to 7 The relationship between tray unit 50 and transfer unit 40 will be described.

[0114] When the fixing device 80 is in Figure 2 In the position shown, the tray handle 52 is hidden by the fixing device 80 and therefore cannot be gripped. Figure 3 As shown, when the fixing device 80 is located outside the first space, the user can hold the tray handle 52 of the tray unit 50 and move the tray unit 50 toward the outside of the device body 1A.

[0115] like Figure 6 and Figure 7 As shown, when an image forming operation is performed on the sheet S, the position of the transfer unit 40 has the following relationship with the first space.

[0116] In other words, when an image forming operation is performed on the sheet S, the transfer unit 40 is located in the second internal position. For example... Figure 6 and Figure 7 As shown, at least a portion of the transfer unit 40 located in the second inner position overlaps with the first space. In other words, when the transfer unit 40 is in the second inner position, at least a portion of the transfer unit 40 is located inside the first space.

[0117] In this embodiment, when the tray unit 50 moves from the first inner position to the first outer position, at least a portion of the transfer unit 40 overlaps with the space traversed by the tray 51. However, it can alternatively be arranged to overlap with the space traversed by the box P. Therefore, compared to a configuration where the transfer unit 40 is located outside the first space in the second inner position, miniaturization of the device body 1A is achieved.

[0118] It should be noted that in the printer 1 according to this embodiment, the portion of the transfer unit 40 that overlaps with the first space is the cleaning portion 43 that accommodates the cleaning member 43A. However, another portion of the transfer unit 40 may also overlap with the first space. Furthermore, in this embodiment, the cleaning member 43A of the transfer unit 40 located in the second inner position overlaps with the first space.

[0119] The tray unit 50 and the transfer unit 40 can be said to satisfy the following relationship: When the tray unit 50 is in the first inner position and the transfer unit 40 is in the second inner position, a portion of the transfer unit 43 (cleaning portion 40) is located downstream of the tray unit 50 in the direction of movement in which the tray unit 50 moves from the first inner position to the first outer position. In the vertical direction V, the area (range) in which the transfer unit 40 is arranged located downstream of the tray unit 50 (cleaning portion 43) at least partially overlaps with the area (range) in which the tray unit 50 is arranged.

[0120] It should be noted that in this embodiment, when the door 20 is closed, at least a portion of the double-sided conveying channel 20a overlaps with the second space traversed by the transfer unit 40 during its movement from the second inner position to the second outer position. That is, when the door 20 is closed, at least a portion of the double-sided conveying channel 20a is located inside the second space.

[0121] As described above, when the transfer unit 40 is in the second internal position, at least a portion of the transfer unit 40 is located inside the first space. Therefore, in this embodiment, when the user moves the tray unit 50 relative to the device body 1A from the first internal position to the first external position, the transfer unit 40 also moves relative to the device body 1A from the second internal position to the second external position. That is, in the integrated state of the transfer unit 40 and the tray unit 50, the tray unit moves from the first internal position to the first external position, and the transfer unit 40 moves from the second internal position to the second external position.

[0122] By moving the tray unit 50 and the transfer unit 40 as a whole, when the tray unit 50 moves to the first external position, the exposure of the photosensitive drum 61 is suppressed, thereby preventing the photosensitive drum 61 from being damaged or contaminated.

[0123] like Figure 7 As shown, when the door 20 is open and the tray unit 50 is in the first external position and the transfer unit 40 is in the second external position, the transfer unit 40 supports the tray unit 50 from below. In this embodiment, the door 20 also supports the transfer unit 40. That is, the transfer unit 40 supported by the door 20 supports the tray unit 50. Alternatively, in this state, the door 20 supports the tray unit 50 via the transfer unit 40.

[0124] refer to Figures 8 to 10A and Figure 10B The configuration for the integrated mobile tray unit 50 and the transfer unit 40 will be described. Figures 8 to 10A and Figure 10B This is a diagram showing the connecting member (i.e., rod, stop, or locking member) 53 that connects the tray 51 of the tray unit 50 to the transfer unit 40.

[0125] The printer 1 according to this embodiment has a locking member 53. In this embodiment, the locking member 53 is disposed on the tray 51 of the tray unit 50. The locking member 53 has a transfer locking portion 53A and is rotatable about a rotation center 53B.

[0126] The tray 51 has a transfer connection portion 51A. The transfer unit 40 includes a drive roller 46, a tension roller 47, and a transfer frame 48, which supports a primary transfer roller 42. The transfer frame 48 is provided with a tray connection groove 48A and a locking connection portion 48B.

[0127] When the locking member 53 rotates around the rotation center 53B, the transfer locking portion 53A engages with the locking connection portion 48B. Therefore, the locking member 53 can move to the connection position where the transfer unit 40 and the tray unit 50 are connected, and to the release position where the transfer unit 40 and the tray unit 50 are retracted from the connection position.

[0128] When the transfer connection portion 51A engages with the tray connection groove 48A, the movement of the tray unit 50 relative to the transfer unit 40 is restricted in the first removal direction Dd1 (pull-out direction) and in directions orthogonal to the first removal direction Dd1. On the other hand, the movement of the transfer unit 40 relative to the tray unit 50 is restricted in the second attachment direction Da2 and in directions orthogonal to the second attachment direction Da2.

[0129] A configuration similar to the above is set at a total of four locations: near the two ends of the tension roller 47 in the direction of rotation axis and near the two ends of the drive roller 46 in the direction of rotation axis.

[0130] When the transfer locking portion 53A of the locking member 53 in the connected position engages with the locking connection portion 48B, the movement of the tray unit 50 relative to the transfer unit 40 is restricted in the first attachment direction Da1 (insertion direction). On the other hand, the movement of the transfer unit 40 relative to the tray unit 50 is restricted in the second removal direction Dd2.

[0131] The locking member 53 and the locking connection part 48B can also be arranged at both ends of the transfer unit 40 along the rotation axis of the tension roller 47.

[0132] In other words, when the transfer connection portion 51A engages with the tray connection groove 48A and the locking member 53, which is in the connection position, engages with the locking connection portion 48B, the relative movement between the transfer unit 40 and the tray unit 50 is restricted. It should be noted that in this state, a clearance may exist between the transfer unit 40 and the tray unit 50.

[0133] In other words, the transfer connection portion 51A and the locking member 53 can be considered as tray-side connectors, while the tray connection groove 48A and the locking connection portion 48B can be considered as transfer-side connectors. When the tray-side connector and the transfer-side connector are connected, the tray unit 50 and the transfer unit 40 are connected and move together.

[0134] On the other hand, such as Figure 9 As shown, the main body 1A of the device has a connecting shaft 581 with a circular cross-section, which is arranged such that it is orthogonal to the direction of movement of the tray unit 50. When the tray unit 50 is in the first inner position and the transfer unit 40 is in the second inner position, the locking member 53 contacts the connecting shaft 581 and is in the released position. In this state, the transfer locking portion 53A is separated from the locking connection portion 48B.

[0135] When the tray unit 50 moves along the first removal direction Dd1 with the locking member 53 in the released position, the transfer unit 40 is pressed by the transfer connecting portion 51A along the second removal direction Dd2. Therefore, the transfer unit 40 also moves integrally with the tray unit 50 along the second removal direction Dd2. When the tray unit 50 moves a specified distance along the first removal direction Dd1, the locking member 53 separates from the connecting shaft 581, moves to the connecting position, and engages with the locking connecting portion 48B. With the locking member 53 in the connecting position and engaged with the locking connecting portion 48B, the tray unit 50 moves to the first external position, and the transfer unit 40 moves to the second external position.

[0136] When the tray unit 50 moves along the first attachment direction Da1 with the locking member 53 engaged with the locking connection portion 48B, the transfer unit 40 is pressed by the locking member 53 along the second attachment direction Da2. Therefore, the transfer unit 40 also moves integrally with the tray unit 50 along the second attachment direction Da2.

[0137] When the transfer unit 40 moves along the second attachment direction Da2 with the locking member 53 engaged with the locking connection portion 48B, the transfer unit 40 presses the transfer connection portion 51A, and the tray unit 50 is pressed along the first attachment direction Da1. Therefore, the tray unit 50 also moves integrally with the transfer unit 40 along the first attachment direction Da1.

[0138] When the tray unit 50 and the transfer unit 40 move together toward the interior of the equipment body 1A, the locking member 53 is moved to the release position via the connecting shaft 581. In this state, even if the tray unit 50 moves along the first attachment direction Da1, the transfer unit 40 does not move. Therefore, during the closing of the door 20, the transfer unit 40 is pressed along the second attachment direction Da2 by the contact force from the secondary transfer roller 45 pressing against the transfer unit 40, and is pressed into the rear (second interior position) of the equipment body 1A. That is, the door 20 can press the transfer unit 40 so that the transfer unit 40 is located in the second interior position. In addition, the door 20 can press the tray unit 50 so that the tray unit 50 is located in the first interior position.

[0139] On the other hand, when the transfer unit 40 moves along the second removal direction Dd2 with the locking member 53 in the released position and the tray unit 50 in the first inner position, the transfer unit 40 can move independently of the tray unit 50 from the second inner position to the second outer position. In the printer 1 according to this embodiment, as... Figure 5 As shown, while the tray unit 50 remains inside the device body 1A (first internal position), the transfer unit 40 can be moved to the outside of the device body 1A (second external position). The transfer unit 40 can be removed from the device body 1A and replaced with a new transfer unit 40.

[0140] In this embodiment, when the tray unit 50 is in the first internal position, it is positioned relative to the device body 1A. Furthermore, when the transfer unit 40 is in the second internal position, there is no gap between the tray connecting groove 48A and the transfer connecting portion 51A, allowing the transfer unit 40 to be precisely positioned relative to the tray unit 50.

[0141] If it is desired to position the tray unit 50 and the transfer unit 40 independently relative to the device body 1A when the tray unit 50 is in the first internal position and the transfer unit 40 is in the second internal position, a gap can be provided between the tray connecting groove 48A and the transfer connecting portion 51A.

[0142] Movement of the tray unit and the transfer unit

[0143] like Figure 1 , Figure 6 and Figure 7 As shown, the tray unit 50 and the transfer unit 40 are tilted relative to the horizontal direction H when they are attached to the main body of the device 1A.

[0144] More specifically, when the tray unit 50 is in the first internal position, the rotation axis of the photosensitive drum 61 positioned closer to the first end 1b1 is positioned higher in the vertical direction V compared to the rotation axis of the photosensitive drum 61 positioned further away from the first end 1b1.

[0145] In other words, when the tray unit 50 is in the first internal position, the second photosensitive drum is positioned closer to the first end 1b1 than the first photosensitive drum, and the rotation axis of the second photosensitive drum is positioned higher in the vertical direction V than the rotation axis of the first photosensitive drum. Similarly, the third photosensitive drum is positioned closer to the first end 1b1 than the second photosensitive drum, and the rotation axis of the third photosensitive roller is positioned higher in the vertical direction V than the rotation axis of the second photosensitive drum. The fourth photosensitive drum is positioned closer to the first end 1b1 than the third photosensitive drum, and the rotation axis of the fourth photosensitive roller is positioned higher in the vertical direction V than the rotation axis of the third photosensitive drum.

[0146] Here, it should be like Figure 1 When viewed along the rotation axis of the photosensitive drum 61 as shown, the straight line connecting the centers of the respective photosensitive drums 61 is defined as the straight line LD. In this embodiment, when the tray unit 50 is in the first inner position, the straight line LD is inclined upward relative to the horizontal direction H from the side farther from the first end 1b1 toward the side closer to the first end 1b1. Furthermore, the contact surfaces of the band 41 that contact the first to fourth photosensitive drums are inclined upward from the side farther from the first end 1b1 toward the side closer to the first end 1b1.

[0147] When the tray unit 50 moves from the first inner position to the first outer position, it moves in a direction inclined relative to the horizontal direction H (in this embodiment, an upward inclination relative to the horizontal direction H). That is, when the tray unit 50 moves from the first inner position to the first outer position, it moves in an upward inclination direction. When the tray unit 50 moves from the first inner position to the first outer position, the direction of movement of the tray unit 50 changes from an upward inclination direction to a downward inclination direction. The direction of movement of the tray unit 50 may also include a direction parallel to the horizontal direction H or a downward inclination direction relative to the horizontal direction H.

[0148] When the tray unit 50 is in the first outer position, the angle formed between the straight line LD and the horizontal direction H is smaller than the angle when the tray unit is in the first inner position. In this embodiment, when the tray unit 50 is in the first outer position, the straight line LD is parallel to the horizontal direction H. However, the straight line LD may also be inclined downward or upward relative to the horizontal direction H.

[0149] Similarly, when the transfer unit 40 moves from the second inner position to the second outer position, the direction of movement of the transfer unit 40 changes from an upward tilt to a downward tilt. The direction of movement of the transfer unit 40 may also include a direction parallel to the horizontal direction H or a downward tilt relative to the horizontal direction H.

[0150] When the transfer unit 40 is in the second outer position, the angle formed between the contact surface of the strip 41 and the horizontal direction H is smaller than the angle when the transfer unit is in the second inner position. In this embodiment, when the transfer unit 40 is in the second outer position, the contact surface of the strip 41 is parallel to the horizontal direction H. However, the contact surface may also be inclined downward or upward relative to the horizontal direction H.

[0151] When the tray unit 50 moves from the first external position to the first internal position, it first moves horizontally in the direction H, and then moves downwards in an inclined direction during the movement. When the transfer unit 40 moves from the second external position to the second internal position, it first moves horizontally in the direction H, and then moves downwards in an inclined direction during the movement. With this configuration, the weight of the tray unit 50 and the transfer unit 40 can be utilized when they are inserted into the device body 1A.

[0152] Pallet unit positioning

[0153] refer to Figures 9 to 12 The method for positioning the pallet unit 50 relative to the device body 1A will be described. Figure 9 This is a cross-sectional view showing the positioning configuration of the tray unit 50 on the front (downstream) side in the insertion direction in the positioning configuration of the tray unit 50 relative to the device body 1A. Figure 11 This is a side view showing the positioning configuration of the tray unit 50 on the rear (upstream) side in the insertion direction in the positioning configuration of the tray unit 50 relative to the device body 1A. Figure 12 This is a schematic diagram showing the planar configuration of the left and right side frames of the device body 1A and the tray unit 50 when viewed from a direction orthogonal to the insertion / removal direction of the tray unit 50 relative to the device body 1A and the rotation axis direction of the photosensitive drum, etc. It should be noted that Figure 10 shows the corresponding configuration of the device body 1A and the tray unit 50 such that the insertion direction Da1 to the removal direction Dd1 are horizontal. In the state where the printer 1 is mounted on a horizontal plane (the generally assumed mounting state), the insertion direction Da1 is a downward-sloping direction from the upstream side to the downstream side.

[0154] like Figure 12As shown, the frame constituting the main body 1A includes a left frame 100L and a right frame 100R. The left frame 100L has a first engaging portion F1 and a second engaging portion R1. The first engaging portion F1 and the second engaging portion R1 are hook-shaped engaging portions. The tray unit 50 has a first engaged portion F2 and a second engaged portion R2. The first engaged portion F2 and the second engaged portion R2 are hook-shaped engaged portions. When the tray unit 50 is inserted, the first engaged portion F2 and the second engaged portion R2 engage with the first engaging portion F1 and the second engaging portion R1 from the upstream side in the insertion direction Da1, respectively. Therefore, the position of the tray unit 50 is restricted in a direction orthogonal to the movement direction of the tray unit 50. In other words, the engagement between the first engaging portion F1 and the first engaged portion F2, and the engagement between the second engaging portion R1 and the second engaged portion R2, restrict the relative movement between the main body 1A and the tray unit 50 in the width direction W (which intersects the insertion / removal direction).

[0155] like Figure 12 As shown, a connecting shaft 581 is arranged on the second end 1b2 side of the device body 1A to connect the left frame 100L and the right frame 100R. The connecting shaft 581 has a circular cross-section, extends in a direction intersecting (orthogonal in this embodiment) the direction of movement of the tray unit 50, and is rotatably disposed relative to the left frame 100L and the right frame 100R. The connecting shaft 581 is configured as an engagement portion provided on the device body 1A so that it can engage with the engagement portion provided on the tray unit 50 when the tray unit 50 is attached to the device body 1A.

[0156] refer to Figure 9 , Figure 10A and Figure 10B The joining portion and the joined portion will be described here. Figure 9 , Figure 10A and Figure 10B The arrangement of the joining portion and the joined portion of the device body 1A and the tray unit 50 on the right side in the width direction W is shown. On the left side, opposite to the right side, a joining portion and the joined portion are also provided, symmetrically arranged along the width direction W. However, the joining portion and the joined portion may also be provided only on one side, either the right or the left side, in the width direction.

[0157] like Figure 9 , Figure 10A and Figure 10BAs shown, a first contact portion 541 and a second contact portion 551 constituting the positioning portion 502R that positions the tray unit 50 relative to the device body 1A are provided on the head end side (i.e., the rear end side in the removal direction) of the tray unit 50 along the attachment direction. The first contact portion 541 and the second contact portion 551 are configured to contact the connecting shaft 581 of the device body 1A. The connecting shaft 581 is arranged relative to the tray unit 50 in the attachment position at a position closer to the head end (downstream end) than the rear end (upstream end) of the tray unit 50 in the attachment position. A third contact portion 561 is also provided on the head end side of the tray unit 50 along the attachment direction to limit the movement limit position of the tray unit 50 relative to the device body 1A in the attachment direction. The third contact portion 561 is also configured to contact the connecting shaft 581 of the device body 1A. The first contact portion 541, the second contact portion 551, and the third contact portion 561 of the positioning portion 502R constitute the engaged portion of the tray unit 50, and the connecting shaft 581 of the device body 1A, which serves as the engaged portion, can engage with the engaged portion.

[0158] The tray unit 50 has a right tray frame 500R facing the right side frame 100R of the device body 1A, and the right tray frame 500R is provided with a guide groove 501R recessed in the direction opposite to the attachment direction (pull-out direction). When the tray unit 50 is inserted into the device body 1A to reach the attachment position, the connecting shaft 581 of the device body 1A is inserted into the guide groove 501R in the insertion / removal direction. A positioning portion 502R (which includes a first contact portion 541 and a second contact portion 551) and a third contact portion 561 form part of a groove forming portion, which forms the guide groove 501R.

[0159] When the tray unit 50 is attached to the device body 1A, the upper surface 504R (which is the generally downward-facing surface area of ​​the guide groove 501R) rests on the connecting shaft 581, thereby supporting the head end side of the tray unit 50 in the insertion direction. The positioning portion 502 (including a first contact portion 541 and a second contact portion 551) is configured as a downward-facing recess on the upper surface 504R of the guide groove 501R, recessed in the upward direction. During the attachment of the tray unit 50 to the device body 1A, the upper surface 504R moves to slide on the connecting shaft 581, and the connecting shaft 581 engages with the positioning portion 502, which is the downward-facing recess. In this embodiment, the connecting shaft 581 is rotatably disposed in the device body 1A. Therefore, when the tray unit 50 is inserted, the relative movement between the connecting shaft 581 and the guide groove 501R becomes smooth.

[0160] The first contact portion 541 is configured to restrict the movement of the tray unit 50 toward the device body 1A in the attachment direction (insertion direction) by contacting the connecting shaft 581. When the tray unit 50 is in an attachment position to the device body 1A, the first contact portion 541 is configured as a first inclined surface that is inclined relative to the insertion / removal direction of the tray unit 50 relative to the device body 1A. The direction in which the first contact portion 541, serving as the first inclined surface, extends is a direction that intersects both the horizontal direction and the direction of gravity. The direction (normal direction) in which the first contact portion 541, serving as the first inclined surface, faces is a direction that includes the component of the insertion direction (Da1) of the tray unit 50 relative to the device body 1A.

[0161] The second contact portion 551 is configured to restrict movement of the tray unit 50 in a direction opposite to the attachment direction of the tray unit 50 relative to the device body 1A (i.e., movement of the tray unit 50 in the pull-out direction) by contacting the connecting shaft 581. When the tray unit 50 is in an attachment position to the device body 1A, the second contact portion 551 is configured as a second inclined surface that is inclined relative to the insertion / removal direction of the tray unit 50 relative to the device body 1A. The direction in which the second contact portion 551, serving as the second inclined surface, extends is a direction that intersects both the horizontal direction and the direction of gravity. The direction (normal direction) in which the second contact portion 551, serving as the second inclined surface, faces is a direction that includes a component of the pull-out direction (Dd1) of the tray unit 50 relative to the device body 1A.

[0162] When both the first contact portion 541 and the second contact portion 551 of the tray unit 50 simultaneously contact the connecting shaft 581 of the device body 1A, the tray unit 50 is positioned relative to the device body 1A in the horizontal direction H. When both the first contact portion 541 and the second contact portion 551 of the tray unit 50 simultaneously contact the connecting shaft 581 of the device body 1A, the tray unit 50 is positioned relative to the device body 1A in the vertical direction V. When both the first contact portion 541 and the second contact portion 551 of the tray unit 50 simultaneously contact the connecting shaft 581 of the device body 1A, the tray unit 50 is positioned relative to the device body 1A in the insertion direction Da1, the pull-out direction Dd1, and directions orthogonal to these directions. When both the first contact portion 541 and the second contact portion 551 of the tray unit 50 simultaneously contact the connecting shaft 581 of the device body 1A, the tray unit 50 is in the positioned position (attached position).

[0163] The third contact portion 561 is disposed at the innermost part of the guide groove 501R, which is located upstream of the first contact portion 541 and the second contact portion 551 along the insertion direction of the tray unit 50. With both the first contact portion 541 and the second contact portion 551 in contact with the connecting shaft 581 (i.e., positioned by the positioning portion 502R), the third contact portion 561 is positioned where it is not in contact with the connecting shaft 581. The guide groove 501R is configured such that its width in the direction intersecting the insertion / removal direction (i.e., the attachment direction and the pull-out direction) of the tray unit 50 has a specified clearance relative to the width of the cross-section of the connecting shaft 581 in the same direction. Therefore, for example, when the tray unit 50 is inserted with excessive force, the tray unit 50 can be inserted such that the connecting shaft 581 can be inserted into the back side of the guide groove 501R beyond the positioning position (i.e., the attachment position) defined by the positioning portion 502R. When the connecting shaft 581 is inserted into the back side of the guide groove 501R beyond the positioning position defined by the positioning portion 502R as described above and then reaches the restricted position, the third contact portion 561 contacts the connecting shaft 581 to restrict the insertion of the tray unit 50. That is, when the third contact portion 561 contacts the connecting shaft 581, it defines the limit position of movement of the tray unit 50 relative to the device body 1A in the attachment direction. When the tray unit 50 is in the restricted position where the third contact portion 561 contacts the connecting shaft 581, the state of contact between the third contact portion 561 and the connecting shaft 581 will not be maintained if no external force is applied to press the tray unit 50 in the attachment direction. Specifically, the tray unit 50 is configured to return to the position positioned by the positioning portion 502R under its own weight. In this embodiment, the downwardly inclined surface from the third contact portion 561 to the first contact portion 541 of the positioning portion 502R is continuously configured as the return portion. When the inclined surface slides over the connecting shaft 581, the connecting shaft 581 is accommodated in the positioning portion 502R (that is, it contacts both the first contact portion 541 and the second contact portion 551), which means that the tray unit 50 automatically returns to the positioning position.

[0164] Figure 18A and Figure 18B This is a schematic diagram illustrating the configuration of the joining portion and the joined portion in this embodiment in a simplified manner. Figure 18A The diagram shows that a third contact portion 561, which is disposed on the tray unit 50 and serves as a limiting portion, contacts a connecting shaft 581, which is disposed on the device body 1A and serves as a joining portion, and that the tray unit 50 is in a restricted position. Figure 18BThe diagram shows a state in which a first contact portion 541 and a second contact portion 551, disposed on the tray unit 50 and forming the joined portion, contact a connecting shaft 581 disposed on the device body 1A and serving as the joined portion, and wherein the tray unit 50 is in an attached position (positioning position). Figure 18A and Figure 18B As shown, the connecting shaft 582 has a first contacted portion 91 that contacts the first contact portion 541, a second contacted portion 92 that contacts the second contact portion 551, and a third contacted portion 93 that contacts the third contact portion 561.

[0165] like Figure 18A As shown, when the tray unit 50 is further inserted downstream in the insertion direction beyond the attachment position (positioning position), the third contact portion 561 of the tray unit 50 contacts the connecting shaft 581 of the device body 1A to restrict the movement of the tray unit 50 in the insertion direction. At this time, the connecting shaft 581 is at least separated from the second contact portion 551. In this embodiment, the connecting shaft 581 is separated from both the first contact portion 541 and the second contact portion 551. At this time, the inclined surface 511 of the tray unit 50 contacts the connecting shaft 581 supporting the tray unit 50 at its head end in the insertion direction in the gravity direction. In the state where the connecting shaft 581 contacts the inclined surface 511, the inclined surface 511 is an inclined surface extending in a direction that intersects both the horizontal direction and the gravity direction. Therefore, when no external force (except gravity) is applied to the tray unit 50, the contact state between the third contact portion 561 and the connecting shaft 581 is not maintained, and the inclined surface 511 slides down the connecting shaft 581 under its own weight, thereby returning the tray unit 50 to the attachment position (positioning position). Therefore, as... Figure 18B As shown, a state is established in which both the first contact portion 541 and the second contact portion 551 are in contact with the connecting shaft 581. That is to say, the inclined surface 511 serves as a return portion.

[0166] exist Figure 18A and Figure 18B In the configuration example shown, the inclined surface 511, used as the return portion, is formed as an inclined surface continuous with the first contact portion 541, and the first contact portion 541 and the inclined surface 511 form a straight line. However, the relationship between the first contact portion 541 and the inclined surface 511 is not limited to the above relationship. For example, the inclined surface 511 can be configured as an inclined surface separate from (discontinuous) from the first contact portion 541, can have a different inclination angle than the first contact portion 541, or can be a surface that is bent or curved in its middle portion. That is, various configurations can be adopted as long as the tray unit 50 can be used as a return portion that moves from the restricted position to the attachment position under its own weight.

[0167] like Figure 12 As shown, the tray unit 50 also has a left tray frame 500L, which faces the left side frame 100L of the device body 1A. Although not shown, the left tray frame 500L is provided with a joining portion having the same configuration as the joining portion provided on the right tray frame 500R, which includes a positioning portion 502R (a first contact portion 541 and a second contact portion 551) and a third contact portion 561.

[0168] like Figure 11 and Figure 12 As shown, a tray shaft 591 extending to the outside of the left frame 100L and right frame 100R of the device body 1A is provided on the side of the tray unit 50 near the tray handle 52 used as a gripping portion. The tray shaft 591 is positioned relative to the tray unit 50 in the attached position, closer to the rear end (upstream end) than the head end (downstream end) of the tray unit 50 in the attachment direction (insertion direction). Fourth contact portions 571L and 571R are respectively provided on the left frame 100L and right frame 100R of the device body 1A. The fourth contact portions 571L and 571R are portions of guide grooves respectively provided on the left frame 100L and right frame 100R, and guide the tray shaft 591 along the insertion / removal direction of the tray unit 50.

[0169] Figure 11 The guide groove 573L of the left frame 100L is shown. The guide groove 573L is formed in a groove shape, extending along the insertion / removal direction of the tray unit 50, and has a lower surface 574L, which is a generally upward-facing surface area. When the tray unit 50 is attached to the device body 1A, the tray shaft 591 rests on the lower surface 574L, thereby the guide groove 573L (lower surface 574L) supports the rear end side of the tray unit 50 in the insertion direction. A fourth contact portion 571L is formed in the guide groove 573L as part of the lower surface 574L. A guide groove 573R with the same configuration is also provided on the right frame 100R. The tray shaft 591 of the tray unit 50 abuts against the fourth contact portions 571L and 571R of the left frame 100L and right frame 100R, respectively. Therefore, the movement of the tray unit 50 relative to the guide groove 573L of the tray shaft 591 is restricted in the direction intersecting the insertion direction of the tray unit 50. Therefore, the pallet unit 50 is positioned relative to the equipment body 1A in the vertical direction V (gravity direction). The pallet shaft 591 has a circular cross-section and is a uniaxial member that penetrates the pallet unit 50.

[0170] The tray unit 50 is configured such that when the positioning portion on the head end side along the attachment direction is positioned by the connecting shaft 581 of the device body 1A, the tray shaft 591 contacts the fourth contact portions 571L and 571R and is positioned on the rear end side along the attachment direction. The length (depth) of the guide groove 573L in the insertion / removal direction of the tray unit 50 is such that even when the tray unit 50 is inserted into a position where the third contact portion 561 contacts the connecting shaft 581 on the head end side along the attachment direction, the tray shaft 591 does not contact the innermost end of the guide groove 573L.

[0171] According to the above configuration, the tray unit 50 is positioned relative to the main body 1A of the equipment.

[0172] Here, with both the first contact portion 541 and the second contact portion 551 in their positioning positions in contact with the connecting shaft 581, the tray unit 50 is in a designated attachment position relative to the device body 1A, and the printer 1 is able to perform an image forming operation. The third contact portion 561 does not directly participate in the positioning of the tray unit 50 during the imaging operation. Therefore, even if deformation (wear) occurs due to repeated pulling and attaching of the tray unit 50 or attachment of the tray unit 50 with excessive force, the impact on the positioning accuracy of the tray unit 50 can be suppressed.

[0173] In this embodiment, the connecting shaft 581 is formed as a uniaxial member with a circular cross-section, which connects the left frame 100L and the right frame 100R. However, the same effect can be achieved even if the shaft does not have a circular cross-section.

[0174] In this embodiment, the first contact portion 541 and the second contact portion 551 constituting the positioning portion 502 are formed as linearly inclined surfaces. The angle formed between the first contact portion 541 and the second contact portion 551 can be arbitrarily set according to the angle of the tray unit 50 relative to the device body 1A or the weight of the tray unit 50. The configuration of the positioning portion 502 is not limited to the configuration of this embodiment. For example, even if the first contact portion 541 and the second contact portion 551 are formed as curved surfaces, the same effect as in this embodiment can be obtained.

[0175] In this embodiment, the third contact portion 561 of the tray unit 50 abuts against the connecting shaft 581 of the device body 1A to limit over-insertion of the tray unit 50. However, the configuration is not limited to this. For example, instead of providing the third contact portion 561 of the tray unit 50, the third contact portion can be provided on the device body 1A. The third contact portion can contact portions other than the connecting shaft 581, as long as the function of limiting over-insertion of the tray unit 50 is ensured and the return portion functions normally.

[0176] Second Embodiment

[0177] refer to Figures 12 to 15 This document describes a method for positioning a tray unit 50 relative to a device body 1A in an image forming apparatus according to a second embodiment of the present disclosure. In this embodiment, components common to the first embodiment are indicated by the same reference numerals, and components different from those in the first embodiment will be described primarily. Matters not specifically described in this embodiment are the same as those in the first embodiment.

[0178] In the first embodiment, the positioning configuration (including the engaging portion and the engaged portion) of the tray unit 50 in the insertion / removal direction is arranged on the front side of the tray unit 50 in the insertion direction, while the positioning configuration of the tray unit 50 in the vertical direction V (gravity direction) is arranged on the rear side of the tray unit 50 in the insertion direction. Conversely, in the second embodiment, the positioning configuration (including the engaging portion and the engaged portion) of the tray unit 50 in the insertion / removal direction is arranged on the rear side of the tray unit 50 in the insertion direction, while the positioning configuration of the tray unit 50 in the vertical direction V (gravity direction) is arranged on the front side of the tray unit 50 in the insertion direction.

[0179] Furthermore, in the first embodiment, the engaging portion is disposed on the device body 1A, and the engaged portion is disposed on the tray unit 50. On the other hand, in the second embodiment, the engaging portion is disposed on the tray unit 50, and the engaged portion is disposed on the device body 1A.

[0180] like Figure 12 As shown, the main body 1A of the device includes a left frame 100L and a right frame 100R. The left frame 100L includes a first joint portion F1 and a second joint portion R1, which can limit the position of the tray unit 50 orthogonal to its direction of movement.

[0181] like Figure 13 and Figure 14A , Figure 14BAs shown, a tray shaft 591 extending to the outer side of the left frame 100L and the right frame 100R is provided on the side of the tray unit 50 near the tray handle 52. The tray shaft 591 is configured to have a circular cross-section and is a single-axis member penetrating the tray unit 50. The tray shaft 591 constitutes a joint portion provided on the tray unit 50. The left frame 100L and the right frame 100R are respectively provided with a first contact portion 542 that restricts the movement of the tray unit 50 in the attachment direction and a second contact portion 552 that restricts the movement of the tray unit 50 in the direction opposite to the attachment direction. The first contact portion 542 and the second contact portion 552 constitute a positioning portion 508 (see FIG. 19) that positions the tray unit 50 relative to the device body 1A. In addition, the left frame 100L and the right frame 100R are provided with a third contact portion 562 that defines the limit position of the movement of the tray unit 50 relative to the device body 1A in the attachment direction. The first contact portion 542, the second contact portion 552, and the third contact portion 562 constituting the positioning portion 508 constitute the engaged portion of the device body 1A, and the tray shaft 591 of the tray unit 50, which serves as the engaged portion, can engage with the engaged portion.

[0182] Figure 14A and Figure 14B The guide groove 575L of the left frame 100L is shown. The guide groove 575L is formed in a groove shape, extending along the insertion / removal direction of the tray unit 50, and has a lower surface 576L, which is a generally upward-facing area. When the tray unit 50 is attached to the device body 1A, the tray shaft 591 rests on the lower surface 576L, thereby supporting the rear end side of the tray unit 50 in the insertion direction. A positioning portion 508, including a first contact portion 542 and a second contact portion 552, is disposed on the lower surface 576L of the guide groove 575L as an upwardly recessed portion that is recessed downward. During the attachment of the tray unit 50 to the device body 1A, the tray shaft 591 moves to slide on the lower surface 576L, and the tray shaft 591 engages with the positioning portion 502, which is the recess. In this embodiment, the tray shaft 591 is rotatably disposed in the tray unit 50. Therefore, when the tray unit 50 is inserted, the relative movement between the tray shaft 591 and the guide groove 575L becomes smooth.

[0183] The first contact portion 542 is configured to restrict the movement of the tray unit 50 toward the device body 1A in the attachment direction (insertion direction) by contacting the tray shaft 591. The first contact portion 542 is configured as a first inclined surface that is inclined relative to the insertion / removal direction of the tray unit 50 relative to the device body 1A. The direction in which the first contact portion 542, serving as the first inclined surface, extends is a direction that intersects both the horizontal direction and the direction of gravity. The direction (normal direction) in which the first contact portion 542, serving as the first inclined surface, faces is a direction that includes the component of the pull-out direction (Dd1) of the tray unit 50 relative to the device body 1A.

[0184] The second contact portion 552 is configured to limit the movement of the tray unit 50 in a direction opposite to the attachment direction of the tray unit 50 relative to the device body 1A (i.e., the movement of the tray unit 50 in the pull-out direction) by contacting the tray shaft 591. The second contact portion 552 is configured as a second inclined surface that is inclined relative to the insertion / removal direction of the tray unit 50 relative to the device body 1A. The direction in which the second contact portion 552, serving as the second inclined surface, extends is a direction that intersects both the horizontal direction and the direction of gravity. The direction (normal direction) facing the second contact portion 552, serving as the second inclined surface, is a direction that includes the component of the insertion direction (Da1) of the tray unit 50 relative to the device body 1A.

[0185] When the tray shaft 591 of the tray unit 50 simultaneously contacts both the first contact portion 542 and the second contact portion 552 of the device body 1A, the tray unit 50 is positioned relative to the device body 1A in the horizontal direction H. When the tray shaft 591 of the tray unit 50 simultaneously contacts both the first contact portion 542 and the second contact portion 552 of the device body 1A, the tray unit 50 is positioned relative to the device body 1A in the vertical direction V. When the tray shaft 591 of the tray unit 50 simultaneously contacts both the first contact portion 542 and the second contact portion 552 of the device body 1A, the tray unit 50 is positioned relative to the device body 1A in the insertion direction Da1, the pull-out direction Dd1, and directions orthogonal to these directions. When the tray shaft 591 of the tray unit 50 simultaneously contacts both the first contact portion 542 and the second contact portion 552 of the device body 1A, the tray unit 50 is in the positioned position (attached position).

[0186] The third contact portion 562 is disposed at the innermost part of the guide groove 575L, which is located downstream of the first contact portion 542 and the second contact portion 552 along the insertion direction of the tray unit 50. The third contact portion 562 is disposed at a position where the tray shaft 591 is in contact with both the first contact portion 542 and the second contact portion 552 (i.e., the tray shaft 591 is positioned by the positioning portion 508), and is not in contact with the tray shaft 591. The guide groove 575L is configured such that its width in the direction intersecting the insertion / removal direction (i.e., the attachment direction and the pull-out direction) of the tray unit 50 has a specified clearance relative to the width of the cross-section of the tray shaft 591 in the same direction. Therefore, for example, when the tray unit 50 is inserted with excessive force, the tray unit 50 can be inserted such that the tray shaft 591 is inserted into the back side of the guide groove 575L beyond the positioning position (i.e., the attachment position) defined by the positioning portion 508. When the tray shaft 591 is inserted into the back side of the guide groove 575L beyond the positioning position defined by the positioning portion 508 as described above and then reaches the restricted position, the tray shaft 591 contacts the third contact portion 562 to restrict the insertion of the tray unit 50. That is, when the third contact portion 562 contacts the tray shaft 591, it defines the limit position of movement of the tray unit 50 relative to the device body 1A in the attachment direction.

[0187] When the tray unit 50 is in the restricted position where the tray shaft 591 contacts the third contact portion 562, the contact between the tray shaft 591 and the third contact portion 562 is not maintained unless an external force is applied to press the tray unit 50 in the attachment direction. Specifically, the tray unit 50 is configured to return to the position positioned by the positioning portion 508 under its own weight. In this embodiment, the inclined surface from the third contact portion 562 to the first contact portion 542 of the positioning portion 508, which slopes downward, is continuously configured as the return portion. When the tray shaft 591 slides over the inclined surface, the tray shaft 591 is accommodated in the positioning portion 508 (i.e., it contacts both the first contact portion 542 and the second contact portion 552), meaning that the tray unit 50 automatically returns to the positioning position.

[0188] Figure 19A and Figure 19B This is a schematic diagram illustrating the configuration of the joining portion and the joined portion in this embodiment in a simplified manner. Figure 19A The diagram shows that a tray shaft 591, which is disposed on the tray unit 50 and serves as a connecting portion, contacts a third contact portion 562, which is disposed on the device body 1A and serves as a limiting portion, and that the tray unit 50 is in a limited position. Figure 19BThe diagram shows a tray shaft 591, which is mounted on the device body 1A and serves as a joining portion, contacting a first contact portion 542 and a second contact portion 552, which are mounted on the tray unit 50 and constitute the joined portion, and the tray unit 50 is in an attached position (positioning position). Figure 19A and Figure 19B As shown, the tray shaft 591 has a first contacted portion 91 that contacts the first contact portion 542, a second contacted portion 92 that contacts the second contact portion 552, and a third contacted portion 93 that contacts the third contact portion 562.

[0189] like Figure 19A As shown, when the tray unit 50 is inserted further downstream in the insertion direction beyond the attachment position (positioning position), the tray shaft 591 of the tray unit 50 contacts the third contact portion 562 of the device body 1A to restrict the movement of the tray unit 50 in the insertion direction. At this time, the tray shaft 591 is at least separated from the second contact portion 552. In this embodiment, the connecting shaft 581 is separated from both the first contact portion 542 and the second contact portion 552. At this time, the tray shaft 591 contacts the inclined surface 512 of the guide groove 575L of the device body 1A in the gravity direction, which supports the rear end side of the tray unit 50 in the insertion direction. In the state where the tray shaft 591 is in contact with the inclined surface 512, the inclined surface 512 is an inclined surface that extends in a direction that intersects both the horizontal direction and the gravity direction. Therefore, when no external force (except gravity) is applied to the tray unit 50, the contact between the tray shaft 591 and the third contact portion 562 is not maintained, and the tray shaft 591 slides down the inclined surface 512 under its own weight, thereby returning the tray unit 50 to the attachment position (positioning position). That is, as Figure 19B As shown, a state is established where the tray shaft 591 is in contact with both the first contact portion 542 and the second contact portion 552. That is, the inclined surface 512 acts as a return portion.

[0190] exist Figure 19A and Figure 19B In the configuration example shown, the inclined surface 512 used as the return portion is formed as an inclined surface continuous with the first contact portion 542, and the first contact portion 542 and the inclined surface 512 form a straight line. However, the relationship between the first contact portion 542 and the inclined surface 512 is not limited to the above relationship. For example, the inclined surface 512 can be configured as an inclined surface separate from (discontinuous) from the first contact portion 542, can have a different inclination angle than the first contact portion 542, or can be a surface that is bent or curved in its middle portion. That is, various configurations can be adopted as long as the tray unit 50 can be used as a return portion that moves from the restricted position to the attachment position under its own weight.

[0191] Although not shown, the right frame 500R of the tray is also provided with a engaged portion having the same configuration as the engaged portion provided on the left frame 500L of the tray, which includes a positioning portion 508 (a first contact portion 542 and a second contact portion 552) and a third contact portion 562.

[0192] like Figure 12 and Figure 15 As shown, a connecting shaft 581 is disposed on the second end 1b2 side of the device body 1A to connect the left frame 100L and the right frame 100R. The tray unit 50 is provided with a fourth contact portion 572. Since the fourth contact portion 572 of the tray unit 50 abuts against the connecting shaft 581 of the device body 1A, the movement of the tray unit 50 relative to the connecting shaft 581 of the guide groove 503R is restricted in a direction intersecting the insertion direction of the tray unit 50. Therefore, the tray unit 50 is positioned in the vertical direction V. The connecting shaft 581 has a circular cross-section and extends in a direction orthogonal to the movement direction of the tray unit 50.

[0193] The tray unit 50 has a right tray frame 500R facing the right side frame 100R of the device body 1A, and the right tray frame 500R is provided with a guide groove 503R recessed in the direction opposite to the attachment direction (pull-out direction). When the tray unit 50 is inserted into the device body 1A until it reaches the attachment position, the connecting shaft 581 of the device body 1A is inserted into the guide groove 503R in the insertion / removal direction. The guide groove 503R has an upper surface 505R, which is a surface area that is substantially downward. When the tray unit 50 is attached to the device body 1A, the upper surface 505R rests on the connecting shaft 581, whereby the connecting shaft 581 supports the head end side of the tray unit 50 in the insertion direction.

[0194] The fourth contact portion 572 is formed as part of the upper surface 505R within the guide groove 503R. A guide groove with the same configuration as the guide groove 503R of the right frame 500R is also provided on the left frame 500L of the tray. When the corresponding fourth contact portions 572 of the left frame 100L and the right frame 100R abut against the connecting shaft 581 of the equipment body 1A, the tray unit 50 is positioned relative to the equipment body 1A in the vertical direction V (gravity direction).

[0195] The tray unit 50 is configured such that when the tray shaft 591 on the rear end side in the attachment direction is positioned by the positioning portion of the device body 1A, the fourth contact portion 572 contacts the connecting shaft 581 and is located on the head end side in the attachment direction. The length (depth) of the guide groove 503R in the insertion / removal direction of the tray unit 50 is such that even when the tray unit 50 is inserted to the position where the tray shaft 591 contacts the third contact portion 562 on the rear end side in the attachment direction, the connecting shaft 581 does not contact the innermost end of the guide groove 503R.

[0196] According to the above configuration, the tray unit 50 is positioned relative to the main body 1A of the equipment.

[0197] Here, with both the first contact portion 542 and the second contact portion 552 in their positioning positions in contact with the tray shaft 591, the tray unit 50 is in a designated attachment position relative to the device body 1A, and the printer 1 is able to perform image forming operations. The third contact portion 562 does not directly participate in the positioning of the tray unit 50 during the imaging operation. Therefore, even if wear occurs due to repeated pulling and attaching of the tray unit 50 or attachment of the tray unit 50 with excessive force, the impact on the positioning accuracy of the tray unit 50 can be suppressed.

[0198] On both sides of the tray handle 52, sheet conveying portions 52A extending from the drive roller 46 of the transfer unit 40 to the fixing device 80 are provided. Furthermore, the drive roller 46 and the fixing device 80, like the tray shaft 591, are positioned by the left frame 100L and the right frame 100R. Because the tray shaft 591, the transfer unit 40, and the fixing device 80 are like... Figure 1 As shown, they are close to each other, so their positions can be ensured with high precision.

[0199] Therefore, it is easier to ensure the distance between the box PY and the fixing device 80, which helps to manage the heat effects from the fixing device 80 and allows for stable sheet delivery.

[0200] In this embodiment, the tray shaft 591 is formed as a single-axis member with a circular cross-section penetrating the tray unit 50. However, the same effect can be achieved even if the shaft does not have a circular cross-section.

[0201] In this embodiment, the first contact portion 542 and the second contact portion 552 constituting the positioning portion 508 are formed as linear inclined surfaces, and the overall shape of the positioning portion 508 is approximately V-shaped. The angle of the V-shape formed between the first contact portion 542 and the second contact portion 552 can be arbitrarily set according to the angle of the tray unit 50 relative to the device body 1A or the weight of the tray unit 50. The configuration of the positioning portion 508 is not limited to the configuration of this embodiment. For example, even if the first contact portion 542 and the second contact portion 552 are formed as curved surfaces, the same effect as in this embodiment can be obtained.

[0202] In this embodiment, the tray shaft 591 of the tray unit 50 abuts against the third contact portion 562 of the device body 1A to limit over-insertion of the tray unit 50. However, the configuration is not limited to this. The third contact portion may contact portions other than the tray shaft 591, as long as the function of limiting over-insertion of the tray unit 50 is ensured and the return portion functions normally.

[0203] Third Embodiment

[0204] refer to Figures 9 to 12 and Figure 16 This document describes a method for positioning a tray unit 50 relative to a device body 1A according to a third embodiment. In this embodiment, components shared with the first and second embodiments are indicated by the same reference numerals, and components different from those in the first and second embodiments will be described primarily. Matters not specifically described in this embodiment are the same as those in the first and second embodiments.

[0205] Figure 16 This is a perspective view showing the positioning configuration of the tray unit 50 relative to the device body 1A at its head end side along the insertion direction according to this embodiment. A connecting shaft 582 is arranged on the second end 1b2 side of the device body 1A to connect the left frame 100L and the right frame 100R. Figure 16 As shown, the connecting shaft 582 has a non-circular engagement portion relative to the right frame 100R. Specifically, the engagement portion with the right frame 100R has a so-called D-shape, comprising an arcuate portion and a flat portion (straight portion). That is, the connecting shaft 582 is configured not to rotate freely relative to the right frame 100R. It should be noted that in Figure 16 In the middle, the right frame 100R is not shown. Except for the non-circular joint portion with the right frame 100R, the connecting shaft 582 has a circular cross section and extends in a direction orthogonal to the movement direction of the tray unit 50.

[0206] The other configurations in the third embodiment are the same as those in the first embodiment.

[0207] In the third embodiment, the connecting shaft 582 cannot rotate freely. Therefore, the same surface of the connecting shaft 582 always abuts against the third contact portion 561.

[0208] like Figure 18A and Figure 18B As shown, the connecting shaft 582 has a first contacted portion 91 that contacts the first contact portion 541, a second contacted portion 92 that contacts the second contact portion 551, and a third contacted portion 93 that contacts the third contact portion 561. Unless the connecting shaft 582 rotates, neither the first contact portion 541 nor the second contact portion 551 contacts the third contacted portion 93, and the third contact portion 561 does not contact either the first contacted portion 91 or the second contacted portion 92.

[0209] Therefore, even if the connecting shaft 582 wears due to repeated pulling and attaching of the tray unit 50 or attaching the tray unit 50 with excessive force, the surfaces of the connecting shaft 582 that contact the first contact portion 541 and the second contact portion 551 remain unaffected. In other words, because the rotation of the connecting shaft 582 is restricted, the areas that contact the first contact portion 541, the second contact portion 551, and the third contact portion 561 are always different from each other. Therefore, even if wear occurs in the area where the connecting shaft 582 contacts the third contact portion 561, the impact on the positioning accuracy of the tray unit 50 can be suppressed more reliably.

[0210] In this embodiment, it is sufficient to prevent the connecting shaft 582 from rotating relative to the left frame 100L and the right frame 100R. The configuration that restricts rotation does not necessarily involve a joint portion with a non-circular shape. The non-circular shape is not limited to a D-shape and may, for example, have multiple flat portions (multiple straight portions).

[0211] Fourth embodiment

[0212] refer to Figures 12 to 15 as well as Figure 17 This document describes a method for positioning a tray unit 50 relative to a device body 1A according to a fourth embodiment. In this embodiment, components common to the first to third embodiments are indicated by the same reference numerals, and components different from those in the first to third embodiments will be described primarily. Matters not specifically described in this embodiment are the same as those in the first to third embodiments.

[0213] Figure 17 This is a perspective view showing the positioning configuration of the tray unit 50 relative to the device body 1A on the rear end side along the insertion direction according to this embodiment. The tray shaft 592, extending to the outer side of the left frame 100L and the right frame 100R, is provided on the side of the tray unit closer to the tray handle 52. Figure 17As shown, the tray shaft 592 has a non-circular engagement portion relative to the tray unit 50. Specifically, the engagement portion with the tray unit 50 has a so-called D-shape, which includes an arcuate portion and a flat portion (straight portion). That is, the tray shaft 592 is configured not to rotate freely relative to the tray unit 50.

[0214] The other configurations in the fourth embodiment are the same as those in the second embodiment.

[0215] In the fourth embodiment, the tray shaft 592 cannot rotate freely. Therefore, the same surface of the tray shaft 592 always abuts against the third contact portion 562.

[0216] like Figure 19A and Figure 19B As shown, the tray shaft 592 has a first contacted portion 91 that contacts the first contact portion 542, a second contacted portion 92 that contacts the second contact portion 552, and a third contacted portion 93 that contacts the third contact portion 562. Unless the tray shaft 592 rotates, neither the first contact portion 542 nor the second contact portion 552 contacts the third contacted portion 93, and the third contact portion 562 does not contact either the first contacted portion 91 or the second contacted portion 92.

[0217] Therefore, even if the tray shaft 592 wears due to repeated pulling and attaching of the tray unit 50 or attaching the tray unit 50 with excessive force, the surfaces of the tray shaft 592 that contact the first contact portion 542 and the second contact portion 552 remain unaffected. In other words, because the rotation of the tray shaft 592 is restricted, the areas that contact the first contact portion 542, the second contact portion 552, and the third contact portion 562 are always different from each other. Therefore, even if wear occurs in the area of ​​the tray shaft 592 that contacts the third contact portion 562, the impact on the positioning accuracy of the tray unit 50 can be suppressed more reliably.

[0218] In this embodiment, the tray shaft 592 only needs to remain non-rotating relative to the tray unit 50. The configuration that restricts rotation does not necessarily involve a joint portion with a non-circular shape. The non-circular shape is not limited to a D-shape and, for example, may have multiple flat portions (multiple straight portions).

[0219] The corresponding configurations described in the above embodiments can be combined with each other.

[0220] According to this disclosure, the effect on the positioning of the pallet relative to the equipment body caused by deformation of at least one of the joining portion and the joined portion can be suppressed.

[0221] While this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the following claims shall be given the broadest interpretation in order to cover all such modifications and equivalent structures and functions.

Claims

1. An image forming apparatus configured to perform an image forming operation on a recording material, the image forming apparatus comprising: an apparatus main body; a pull-out portion movable with respect to the apparatus main body in an insertion direction and a pull-out direction opposite to the insertion direction, the pull-out portion being movable with respect to the apparatus main body to an attached position, a pulled-out position downstream of the attached position in the pull-out direction, and a restricted position downstream of the attached position in the insertion direction; an engaging portion provided on one of the apparatus main body and the pull-out portion; and an engaged portion provided on the other of the apparatus main body and the pull-out portion, wherein the engaged portion includes: a positioning portion including a first contact portion and a second contact portion, the first contact portion and the second contact portion of the positioning portion being in contact with the engaging portion with the pull-out portion in the attached position, movement of the pull-out portion in the insertion direction being limited by contact between the first contact portion and the engaging portion, movement of the pull-out portion in the pull-out direction being limited by contact between the second contact portion and the engaging portion, a restricting portion configured to come into contact with the engaging portion with the pull-out portion reaching the restricted position to restrict movement of the pull-out portion in the insertion direction, and a returning portion configured to come into contact with the engaging portion with the pull-out portion in the restricted position so that the pull-out portion moves from the restricted position to the attached position under its own weight.

2. The image forming apparatus according to claim 1, wherein the image forming operation is able to be performed in a state where the pull-out portion is in the attached position.

3. The image forming apparatus according to claim 2, wherein the engaging portion includes a first contacted portion configured to be in contact with the first contact portion, a second contacted portion configured to be in contact with the second contact portion, and a third contacted portion configured to be in contact with the restricting portion, and the first contacted portion, the second contacted portion, and the third contacted portion are arranged at mutually different positions.

4. The image forming apparatus according to claim 1 or 2, wherein the insertion direction is downwardly inclined from an upstream side toward a downstream side.

5. The image forming apparatus according to claim 4, wherein movement of the pull-out portion in a direction intersecting the insertion direction is limited by contact of the engaging portion with the first contact portion and the second contact portion.

6. The image forming apparatus according to claim 1 or 2, wherein rotation of the engaging portion with respect to one of the apparatus main body and the pull-out portion is limited.

7. The image forming apparatus according to claim 1 or 2, further comprising: a cartridge removably mounted on the pull-out portion. ​ 8. The image forming apparatus according to claim 1 or 2, wherein the return portion extends in a direction intersecting both a horizontal direction and a gravitational direction, in a state where the engaging portion is in contact with the return portion.

9. The image forming apparatus according to claim 1 or 2, wherein the pull-out portion has the engaging portion, and the apparatus main body has the engaged portion.

10. The image forming apparatus according to claim 9, wherein the restricted portion is located downstream of the first contact portion and the second contact portion in the insertion direction.

11. The image forming apparatus according to claim 9 or 10, wherein the first contact portion is a first inclined surface, and the second contact portion is a second inclined surface, and wherein the first inclined surface extends in a direction intersecting both a horizontal direction and a gravitational direction, and the second inclined surface extends in a direction intersecting both the horizontal direction and the gravitational direction.

12. The image forming apparatus according to claim 9 or 10, wherein the pull-out portion has an upstream end and a downstream end in the insertion direction, and the engaging portion is located closer to the upstream end than to the downstream end.

13. The image forming apparatus according to claim 1 or 2, wherein the pull-out portion has the engaged portion, and the apparatus main body has the engaging portion.

14. The image forming apparatus according to claim 13, wherein the restricted portion is located upstream of the first contact portion and the second contact portion in the insertion direction.

15. The image forming apparatus according to claim 13 or 14, wherein the first contact portion is a first inclined surface, and the second contact portion is a second inclined surface, and wherein, when the pull-out portion is in the attached position, the first inclined surface extends in a direction intersecting both a horizontal direction and a gravitational direction, and the second inclined surface extends in a direction intersecting both the horizontal direction and the gravitational direction.

16. The image forming apparatus according to claim 13 or 14, wherein the pull-out portion has an upstream end and a downstream end in the insertion direction, and the engaging portion is located closer to the downstream end than to the upstream end.

Images