Image forming apparatus

Abstract

This prevents deformation of at least one of the engaging portion and the engaged portion from affecting the positioning of the tray relative to the device body. [Solution] The image forming apparatus has an engagement portion on one of the apparatus body and the pull-out portion, and a engaged portion on the other, which includes a first contact portion and a second contact portion, and when the pull-out portion is in the mounting position, the first contact portion, the second contact portion and the engagement portion come into contact, restricting the movement of the pull-out portion in the insertion direction by the contact between the first contact portion and the engagement portion, and restricting the movement of the pull-out portion in the pull-out direction by the contact between the second contact portion and the engagement portion; a restricting portion that comes into contact with the engagement portion when the pull-out portion reaches a restricted position downstream of the mounting position and restricts the movement of the pull-out portion in the insertion direction; and a return portion that comes into contact with the engagement portion when the pull-out portion is in the restricted position and moves the pull-out portion from the restricted position to the mounting position by the weight of the pull-out portion.

Description

Technical Field

[0004] ,

[0001] The present invention relates to a positioning device for positioning a drawer unit with respect to a device main body and an image forming apparatus including the same.

Background Art

[0002] In image forming apparatuses such as printers, copiers, and multifunction devices, there is a type in which a cartridge in which a photosensitive drum and process means acting on the photosensitive drum are integrally cartridge-ized is removably mounted on a tray (drawer unit) that moves between the inside and outside of the device main body. Conventionally, an image forming apparatus has been proposed in which an engaging portion is provided on one of the device main body and the tray, and an engaged portion is provided on the other, and the engagement of the engaging portion and the engaged portion enables positioning of the tray in the mounting direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When at least one of the engaging portion and the engaged portion is deformed, the position of the tray with respect to the device main body changes.

[0005] An object of the present invention is to provide a technology capable of suppressing the influence of deformation of at least one of the engaging portion and the engaged portion on the positioning of the tray with respect to the device main body.

Means for Solving the Problems

[0006] To achieve the above object, the image forming apparatus of the present invention is an image forming apparatus configured to be capable of performing an image forming operation on a recording material, a device main body, A pull-out section movable relative to the device body in an insertion direction and a pull-out direction opposite to the insertion direction, wherein the pull-out section is movable relative to the device body to a mounting position, a pull-out position located downstream of the mounting position in the pull-out direction, and a restricted position located downstream of the mounting position in the insertion direction. The device body and the drawer portion are provided with an engaging portion, The engagement portion provided on the other side of the device body and the drawer portion, A positioning portion including a first contact portion and a second contact portion, wherein when the pull-out portion is in the mounting position, the first contact portion, the second contact portion and the engaging portion come into contact, the contact between the first contact portion and the engaging portion restricts the movement of the pull-out portion in the insertion direction, and the contact between the second contact portion and the engaging portion restricts the movement of the pull-out portion in the pull-out direction, When the pull-out portion reaches a restricted position downstream of the mounting position in the insertion direction, a restricting portion comes into contact with the engaging portion and restricts the movement of the pull-out portion in the insertion direction, A return portion that contacts the engaging portion when the pull-out portion is in the restricted position, and moves the pull-out portion from the restricted position to the mounting position by the weight of the pull-out portion, A engaged portion having, It is characterized by having the following features. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress the effect of deformation of at least one of the engaging portion and the engaged portion on the positioning of the tray relative to the device body. [Brief explanation of the drawing]

[0008] [Figure 1] Diagram illustrating the overall configuration of the image forming apparatus in Example 1. [Figure 2] Diagram illustrating the image forming apparatus with the door open. [Figure 3] Diagram illustrating the image forming apparatus with the fixing device moved. [Figure 4] Explanatory drawing of an image forming apparatus when a transfer unit and a tray unit are pulled out [Figure 5] Explanatory drawing of an image forming apparatus in a state where the transfer unit is pulled out alone [Figure 6] Explanatory drawing of the movement of the transfer unit and the tray unit in Example 1 [Figure 7] Explanatory drawing of the movement of the transfer unit and the tray unit in Example l [Figure 8] Explanatory drawing of a connecting member connecting the tray and the transfer unit in Example 1 [Figure 9] Explanatory drawing of a connecting member connecting the tray and the transfer unit in Example 1 [Figure 10] Explanatory drawing of the positioning of the tray unit and the apparatus main body in Example 1 [Figure 11] Explanatory drawing of the positioning of the tray unit and the apparatus main body in Example 1 [Figure 12] Upper sectional view of the apparatus main body [Figure 13] Explanatory drawing of the tray handle of the tray unit in Example 2< [Figure 14] Explanatory drawing of the positioning of the tray unit and the apparatus main body in Example 2 [Figure 15] Explanatory drawing of the positioning of the tray unit and the apparatus main body in Example 2 [Figure 16] Explanatory drawing of the positioning of the tray unit and the apparatus main body in Example 3< [Figure 17] Explanatory drawing of the positioning of the tray unit and the apparatus main body in Example 4<< [Figure 18] Explanatory drawing of the configuration of the engaging portion and the engaged portion in Example 1 [Figure 19] Explanatory drawing of the configuration of the engaging portion and the engaged portion in Example 2< <<

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments for implementing the present invention will be exemplarily described in detail based on the embodiments with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the device to which the invention is applied and various conditions. That is, the scope of the present invention is not intended to be limited to the following embodiments. Also, not all of the features described in the following embodiments are essential for the solution means of the invention. <Example 1>

[0010] [Overall Configuration] The printer 1 as an image forming apparatus will be described with reference to FIG. 1. FIG. 1 is a diagram for explaining the overall configuration of the printer 1 according to this embodiment. In this embodiment, the printer 1 is an electrophotographic color laser beam printer that forms an image on a sheet S as a recording material.

[0011] The printer 1 has a device main body (housing) 1A, a scanner (exposure device) 2, a control unit 3, and a door (opening / closing member) 20 that can be opened and closed with respect to the device main body 1A. Further, the printer 1 has a sheet feeding unit 30, a transfer unit (transfer device) 40, a tray unit (moving unit, support unit) 50, and a fixing device 80. The part including the device main body 1A and the door 20 can also be called a main frame 100. The main frame 100 includes the exterior of the printer 1.

[0012] The device main body 1A houses the scanner 2, the control unit 3, the sheet feeding unit 30, the transfer unit 40, the tray unit 50, and the fixing device 80. The sheet feeding unit 30 has a stacking tray 31 for stacking the sheet S as a recording material and a supply roller 32. The stacking tray 31 can be pulled out in the direction of the door 20 to replenish the sheet S. The tray unit 50 has a tray (support member, drawer) 51 and cartridges PY, PM, PC, PK. The tray 51 has a tray handle 52. The cartridges PY, PM, PC, PK are detachably mounted on the tray 51.

[0013] Each of the cartridges PY, PM, PC, and PK is independently removable from the tray 51. Each cartridge contains yellow (Y), magenta (M), cyan (C), and black (K) toner (developer), respectively. The cartridges PY, PM, PC, and PK have the same configuration except for the color of the toner they contain. Therefore, the configuration and operation of one of the cartridges PY, PM, PC, or PK may be described, while the others are omitted. Also, when there is no need to distinguish between cartridges PY, PM, PC, and PK, they may simply be referred to as cartridge P. The tray unit 50 can be said to have multiple cartridges P and a tray 51 into which the multiple cartridges P are removablely mounted.

[0014] In this embodiment, the tray unit 50 has a plurality of photosensitive drums (image carriers) 61, a plurality of charging rollers 62 (charging members), and a plurality of 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 rotational axis directions of the photosensitive drums 61, the developing rollers 71, and the charging rollers 62 are parallel.

[0015] The part that forms the black (K) image is called the black station (first station), and the photosensitive drum 61 of the first station is called the first photosensitive drum, the developing roller 71 is called the first developing roller, and the charging roller 62 is called the first charging roller. The part that forms the cyan (C) image is called the cyan station (second station), and the photosensitive drum 61 of the second station is called the second photosensitive drum, the developing roller 71 is called the second developing roller, and the charging roller 62 is called the second charging roller. The part that forms the magenta (M) image is called the magenta station (third station), and the photosensitive drum 61 of the third station is called the third photosensitive drum, the developing roller 71 is called the third developing roller, and the charging roller 62 is called the third charging roller. The part that forms the yellow (Y) image is called the yellow station (fourth station), and the photosensitive drum 61 of the fourth station is called the fourth photosensitive drum, the developing roller 71 is called the fourth developing roller, and the charging roller 62 is called the fourth charging roller. Cartridge PK is installed in the black station, cartridge PC in the cyan station, cartridge PM in the magenta station, and cartridge PY in the yellow station. In this embodiment, cartridge PK is referred to as the first cartridge, cartridge PC as the second cartridge, cartridge PM as the third cartridge, and cartridge PY as the fourth cartridge.

[0016] The numbers 1, 2, 3, and 4 are used for explanatory purposes only.

[0017] The photosensitive drum 61, the charging roller 62, and the developing roller 71 may be provided in either the cartridge P or the tray 51. In this embodiment, the cartridge P has the photosensitive drum 61, the charging roller 62, and the developing roller 71.

[0018] The transfer unit 40 includes a belt 41, a primary transfer roller 42, a cleaning unit 43, a drive roller 46 for driving the belt 41, and a tension roller (driven roller) 47. In this embodiment, the printer 1 is equipped with an optical sensor 44 for detecting the toner image transferred to the belt 41. In this embodiment, the belt 41 is positioned below the photosensitive drum 61 and is in contact with the photosensitive drum 61 so that a primary transfer section is formed between the belt 41 and the photosensitive drum 61. The printer 1 also has a secondary transfer roller 45 that contacts the belt 41 so that a secondary transfer section is formed. The secondary transfer section is formed between the belt 41 and the secondary transfer roller 45. The rotational axis directions of the primary transfer roller 42, the drive roller 46, the tension roller 47, and the secondary transfer roller 45 are parallel. A pair of registration rollers 4 is positioned in front of the secondary transfer section.

[0019] The fixing device 80 includes a fixing unit 81 and a flapper 5. When an image forming operation is performed on the sheet S, the fixing device 80 is in the use position. The fixing device 80 is housed inside the main body 1A when in the use position. The fixing device 80 is also configured to heat the sheet S when in the use position. In this embodiment, the fixing unit 81 includes a heating unit (heating roller) including a heater and a pressurizing unit (pressurizing roller).

[0020] The movement of the transfer unit 40 and the tray unit 50 will be explained using Figures 1, 2, 3, 4, and 5. Figure 2 shows the printer 1 with the door 20 open. Figure 3 shows the printer 1 with the fuser 80 moved. Figure 4 shows the printer 1 with the transfer unit 40 and the tray unit 50 extended. Figure 5 shows the printer 1 with the transfer unit 40 extended independently.

[0021] The transfer unit 40 and the tray unit 50 are movable from the inside to the outside 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 to a first inner position inside the device body 1A and to a first outer position outside the device body 1A. The transfer unit 40 is movable through the opening 1A1 to a second inner position inside the device body 1A and to a second outer 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 inner position to the second outer position, at least the belt 41 moves, and at least a portion of the belt 41 protrudes from the device body 1A toward the outside of the device body 1A.

[0022] The direction in which the tray unit 50 moves from the first inner position to the first outer position is called the tray removal direction Dd1 (pull-out direction), and the direction opposite to the tray removal direction Dd1 is called the tray installation direction Da1 (mounting direction). The tray removal direction Dd1 can be said to be the direction from the second end 1b2 to the first end 1b1.

[0023] The direction in which the transfer unit 40 moves from the second inner position to the second outer position is called the transfer removal direction Dd2, and the direction opposite to the transfer removal direction Dd2 is called the transfer mounting direction Da2. In the transfer removal direction Dd2, the drive roller 46 is located downstream of the tension roller 47. The transfer removal direction Dd2 can be described as the direction from the second end 1b2 to the first end 1b1.

[0024] The tray removal direction Dd1 and the tray mounting direction Da1 are directions that intersect (preferably orthogonal to) the rotation axis direction of the photosensitive drum 61. The transfer removal direction Dd2 and the transfer mounting direction Da2 are directions that intersect (preferably orthogonal to) the rotation axis direction of the drive roller 46. The rotation axis direction of the drive roller 46 is parallel to the rotation axis direction of the photosensitive drum 61.

[0025] In the horizontal direction H, a fixing device 80 is positioned on one end of the device body 1A (the side on which the first end portion 1b1 is located).

[0026] The door 20 attached to the main body 1A of the device is movable between the closed position and the open position. As shown in Figure 1, when the door 20 is in the closed position (closed state), the door 20 covers the opening 1A1. As shown in Figure 2, when the door 20 is in the open position (open state), the opening 1A1 is exposed.

[0027] As shown in Figure 1, when the door 20 is in the closed position, the door 20 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 functions as part of the exterior.

[0028] The door 20 can move between an open position and a closed position while the fixing device 80 is supported by the device body 1A. In other words, the door 20 moves from the closed position to the open position so as to move away from the fixing device supported by the device body 1A. Therefore, as shown in Figure 2, when the door 20 is in the open position, the door 20 is away from the fixing device 80 supported by the device body 1A.

[0029] As will be described later, the fixing device 80 can be moved from the state in Figure 2 to the state in Figure 3 so that the opening 1A1 is widely exposed. With the door 20 and fixing device 80 moved (Figure 3), the transfer unit 40 and tray unit 50 can move from the inside to the outside of the device body 1A through the opening 1A1, and after the move, it will be in the state in Figure 4.

[0030] With the tray unit 50 moved outside the main body 1A of the device (Figure 4), it is permissible to remove cartridges PY, PM, PC, and PK from the tray 51 and to install cartridges PY, PM, PC, and PK onto the tray 51. This allows cartridges PY, PM, PC, and PK to be replaced with new cartridges PY, PM, PC, and PK. In this embodiment, cartridge P is detachable from the tray 51 in a direction intersecting (preferably perpendicular to) the rotation axis of the photosensitive drum 61.

[0031] Cartridges PY, PM, PC, and PK are removed from tray 51 by moving away from the transfer unit 40 relative to the tray 51. In other words, cartridges PY, PM, PC, and PK are removed from tray 51 by moving away from the transfer unit 40 relative to the tray 51. In this embodiment, the transfer unit 40 is located below the tray unit 50. Therefore, cartridges PY, PM, PC, and PK are removed from tray 51 by moving upward relative to the tray 51.

[0032] 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.

[0033] [Image Formation Process] The image formation operation of printer 1 will be explained using Figure 1. The control unit 3 of printer 1 starts the image formation operation on the sheet S based on the image signal received from the external host device 400. The external host device 400 is, for example, a personal computer, an image reader, and a facsimile machine.

[0034] 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 inner position, the transfer unit 40 is in the second inner position, and the door 20 is in the closed position. With the transfer unit 40 in the second inner position, the belt 41 can contact the photosensitive drum 61. At this time, the tray unit 50 is positioned above the transfer unit 40.

[0035] A charging voltage is applied to the charging roller 62, causing the photosensitive drum 61 to rotate. Corresponding to the image information A laser is shone from the scanner 2 onto the photosensitive drum 61, and the surface of the photosensitive drum 61, which has been charged by the charging roller 62, is exposed. As a result, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum 61.

[0036] 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, forming a toner image on the surface of the photosensitive drum 61. In this embodiment, the developing roller 71 develops the electrostatic latent image while in contact with the photosensitive drum 61, but the developing roller 71 may develop the electrostatic latent image with a gap between the developing roller 71 and the photosensitive drum 61.

[0037] When a full-color image is formed, toner images of each color are formed on each photosensitive drum 61.

[0038] In this embodiment, with the tray unit 50 in the first inner position, the developing roller 71 is movable between a contact position in contact with the photosensitive drum 61 and a separated position away from the photosensitive drum 61. Specifically, a switching device provided in the main body 1A switches between the developing roller 71 being in the contact position and the developing roller 71 being in the separated position. This allows the developing roller 71 to be kept away from the photosensitive drum 61 when no image forming operation is being performed.

[0039] Furthermore, printer 1 can perform monochrome printing with the developing roller 71 and photosensitive drum 61 corresponding to cartridge PK in contact, and with the developing roller 71 and photosensitive drum 61 corresponding to cartridges PY, PM, and PC separated. Also, printer 1 can perform full-color printing with the photosensitive drum 61 and belt 41 corresponding to cartridges PY, PM, PC, and PK in contact.

[0040] The toner images formed on each photosensitive drum 61 are transferred onto the belt 41 by the primary transfer roller 42 in the primary transfer section and transported toward the secondary transfer section formed by the belt 41 and the secondary transfer roller 45.

[0041] Meanwhile, the main body 1A of the device has a transport path (first path, first transport path) 1c through which the sheet S heading toward the fixing device 80 passes. The door 20 also has a double-sided transport path (second path, second transport path) 20a through which the sheet S that has passed through the fixing device 80 passes. When the door 20 is closed, it covers the transport path 1c. When the door 20 is opened, the transport path 1c and the double-sided transport path 20a are exposed (Figure 2).

[0042] In the sheet feeding unit 30, one sheet S is separated and fed from the sheets S loaded on the loading tray 31 by the supply roller 32 at a predetermined timing, and is transported through the transport path 1c toward the secondary transfer unit and the fixing device 80.

[0043] In the secondary transfer section, the toner image is transferred from the belt 41 to the sheet S. Toner that is not transferred to the sheet S is removed from the belt 41 by a cleaning blade (cleaning member) 43A provided in the cleaning section 43.

[0044] The sheet S onto which the toner image has been transferred in the secondary transfer section is transported toward the fuser unit 80. In the fuser unit 80, the sheet S is heated and pressurized in the fuser section 81, and the toner image is fixed to the sheet S. The sheet S with the fixed toner image is transported toward the flapper 5, which acts as a path switching section.

[0045] The flapper 5 guides the sheet S that has passed through the fuser 80 toward the paper output path 1d. It is movable between its initial position and a reversal position that guides it toward the reversal path 1e.

[0046] When single-sided printing is performed, in which an image is formed on one side of the sheet S, the sheet S is guided by the flapper 5 to the paper output path 1d and discharged into the output tray 1f formed on the top of the main body 1A of the device.

[0047] On the other hand, when double-sided printing is performed in which an image is printed on one side and the other side of the sheet S, the sheet S is guided to the reversal path 1e by the flapper 5. After the sheet S is guided to the reversal path 1e, the transport direction of the sheet S is reversed, and the sheet S is transported through the double-sided transport path 20a formed in the door 20 toward the secondary transfer section. In the secondary transfer section, after the toner image is transferred to the back side of the sheet S, the sheet S passes through the fuser 80, is guided to the paper discharge path 1d by the flapper 5, and is discharged into the discharge tray 1f of the main body 1A.

[0048] [Removal of tray unit and transfer unit, and placement of fixing device] Figures 1, 2, 3, 4, and 5 will be used to explain the removal of the tray unit 50 and the transfer unit 40 from the main body 1A of the apparatus, and the arrangement of the fixing device 80.

[0049] As described above, the fuser unit 80 of the printer 1 is located horizontally on one end of the device body 1A. 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.

[0050] In other words, with respect to the horizontal direction H, the fixing device 80 is closer to the first end 1b1 than to the second end 1b2. That is, with respect to 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 than to the center of the device body 1A in the horizontal direction H, and it can be said that the distance between the first end 1b1 and the fixing device 80 in the horizontal direction H is shorter than the distance between the first end 1b1 and the center of the device body 1A.

[0051] Furthermore, 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 in a direction that intersects the rotation axis of the photosensitive drum 61. At this time, the tray unit 50 moves away from the second end 1b2.

[0052] 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 in a direction that intersects the rotation axis of the drive roller 46. At this time, the transfer unit 40 moves away from the second end 1b2.

[0053] As described above, the door 20 in this embodiment covers the opening 1A1 when closed and also covers at least a portion of the sheet S transport path 1c. The door 20 also has a double-sided transport path 20a. If a sheet S jams (hereinafter referred to as a jam), the user of the printer 1 can remove the sheet S from one end of the device body 1A to clear the jam. Specifically, the door 20 can be moved to the open position to access the inside of the device body 1A and remove the sheet S. Also, if a portion of the sheet S that has passed through the fuser 80 is exposed to the outside of the device body 1A, the sheet S can be pulled from the outside of the device body 1A and removed without opening the door 20.

[0054] Furthermore, the user of printer 1 can move the transfer unit 40 and tray unit 50 from one end of the main unit 1A to the outside of the main unit 1A to perform tasks such as checking the condition of the transfer unit 40 and cartridge P, maintenance, and replacement.

[0055] In other words, the printer 1 has the fuser unit 80 located on one end of the main unit 1A, and the main unit The transfer unit 40 and the tray unit 50 can be moved in and out of the main body 1A through one end of the main body 1A. As a result, the user can clear jams, access the fixing device 80, and operate the transfer unit 40 and the tray unit 50 from one direction.

[0056] In this embodiment, the printer 1 has its front facing the door 20. Therefore, it is sufficient to have enough space to perform tasks such as clearing jams and operating the transfer unit 40 and tray unit 50 from the front of the printer 1. On the other hand, it is not necessary to have enough space to perform these tasks from the left, right, back, or top of the printer 1. Therefore, the printer 1 can be installed in a space-saving manner.

[0057] If the transfer unit 40 or tray unit 50 is pulled out from the other end of the device body 1A, the user needs to access both ends of the device body 1A to clear the jam and pull out the transfer unit 40 or tray unit 50. Similarly, if one of the transfer unit 40 or 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 also needs to access both ends of the device body 1A. As a result, space is required to work from both the front and the back of the device body 1A, increasing the area required to install the printer 1.

[0058] Furthermore, in this embodiment, the sheets S can be replenished from one end of the device body 1A. Therefore, it is sufficient to have space to replenish the sheets S from the front of the printer 1, and the printer 1 can be installed in a space-saving manner.

[0059] [Relationship between tray unit and fuser] The relationship between the tray unit 50 and the fixing device 80 will be explained using Figures 1, 2, 3, 4, 6, and 7. Figures 6 and 7 illustrate the movement of the transfer unit 40 and the tray unit 50.

[0060] The tray unit 50 passes through a predetermined space when moving from a first inner position (mounting position) where image forming operations are performed on the sheet S, to a first outer position (extraction position) where cartridge P can be replaced. The space through which the tray unit 50 passes when moving from the first inner position to the first outer position is called the first space (the movement space of the tray unit 50). The first space can also be called the path or trajectory (first movement path, first movement trajectory) through which the tray unit 50 passes when moving from the first inner position to the first outer position.

[0061] As the transfer unit 40 moves from the second inner position where the image forming operation on the sheet S is performed to the second outer position, it passes through a predetermined space. The space through which the transfer unit 40 moves 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 called the path or trajectory (second movement path, second movement trajectory) through which the transfer unit 40 moves from the second inner position to the second outer position.

[0062] The position (usage position) of the fixing device 80 when the image forming operation is performed on the sheet S, and the first space and the second space have the following relationship.

[0063] In other words, as shown in Figures 6 and 7, at least a portion of the fixing device 80 in the operating position overlaps with the first space. To put it another way, when the fixing device 80 is in the operating position, at least a portion of the fixing device 80 is inside the first space.

[0064] In this embodiment, at least a part of the fixing device 80 is such that the tray unit 50 is first inside When moving from the side position to the first outer position, the space through which the cartridge P passes overlaps, but it may also be arranged to overlap with the space through which the tray 51 passes.

[0065] This allows the main body of the device 1A to be made smaller compared to a configuration in which the fixing device 80 at the point of use is located outside the first space.

[0066] As shown in Figure 6, in this embodiment, when the door 20 is closed, at least a portion of the double-sided transport path 20a overlaps with the first space. That is, when the door 20 is closed, at least a portion of the double-sided transport path 20a is inside the first space.

[0067] As described above, at least a portion of the fixing device 80 in the use position is inside the first space. Therefore, when the fixing device 80 is in the use position, the tray unit 50 is restricted from moving from the first inner position to the first outer position. On the other hand, the fixing device 80 is configured to be retractable from the use position. When the fixing device 80 is retracted from the use position, the tray unit 50 is permitted to move from the first inner position to the first outer position. When the tray unit 50 moves from the first inner position to the first outer position, the tray unit 50 passes below the fixing device 80. The fixing device 80 is outside the second space in both the use position and the retracted position. Therefore, in both the use position and the retracted position, the transfer unit 40 can move from the second inner position to the second outer position. When the transfer unit 40 moves from the second inner position to the second outer position, the transfer unit 40 passes below the fixing device 80.

[0068] The fixing device 80 has a fixing frame 80a that supports the fixing section 81. When the fixing device 80 is moved away from the operating position, the fixing frame 80a is displaced relative to the device body 1A while supporting the fixing section 81.

[0069] When pulling the tray unit 50 out of the main body 1A of the device, first, the door 20 is moved to the open position as shown in Figure 2. In this embodiment, with the fixing device 80 in the use position, the door 20 can be moved to the open position and the closed position. Then, with the door 20 in the open position, and with the door 20 in the open position, the fixing device 80 is moved from the use position to the retracted position so as to move it out of the first space as shown in Figure 3.

[0070] In the printer 1 of this embodiment, the fuser unit 80 is attached to the main unit 1A and is movable between a working position and a retracted position, which is a position moved away from the working position. In this embodiment, when the fuser unit 80 is in the retracted position, the entire fuser unit 80 is located outside the first space.

[0071] The fuser unit 80 is lifted from its operating position and positioned in a retracted position above the operating position. In other words, the retracted position is higher than the operating position. As shown in Figure 7, when the fuser unit 80 is in the retracted position, at least a portion of the fuser unit 80 protrudes from the device body 1A toward the outside. Furthermore, when the fuser unit 80 is in the retracted position, at least a portion of the fuser unit 80 is higher than the position of the upper cover portion 20b of the door 20 in the closed position. This allows the size of the printer 1 to be kept small in the vertical direction V when the fuser unit 80 is in the operating position, while the movement of the fuser unit 80 to the retracted position secures space for the tray unit 50 to move. Note that when the fuser unit 80 is in the retracted position, the door 20 is restricted from taking the closed position.

[0072] Specifically, the printer 1 has a connecting member (fuser connecting member, fuser link, arm) 85 that is movably connected to the main body 1A of the device. The fuser device 80 is connected to the main body 1A of the device via the connecting member 85.

[0073] The connecting member 85 is rotatable about a rotation center 85A, and when the tray unit 50 is pulled out to the outside of the device body 1A, the connecting member 85 is moved to the outside of the first space. A 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 a rotation center 85A. The fixing device 80 is movable from the use position to the retracted position and from the retracted position to the use position while supported by the connecting member 85 (connected to the device body 1A via the connecting member 85). The connecting member 85 is configured to be movable (oscillating) relative to the device body 1A and the fixing device 80. In other words, the fixing device 80 is connected to the device body 1A via the connecting member 85. As a result, the amount of movement of the fixing device 80 when it moves between the retracted position and the use position can be increased compared to a configuration in which the fixing device 80 is directly connected to the device body 1A.

[0074] As shown in Figure 7, when the tray unit 50 moves from the first inner position to the first outer position, the angle between the direction of movement of the tray unit 50 and the horizontal direction H is smaller than the angle between the direction of movement of the tray unit 50 and the vertical direction V. Furthermore, when the fixing device 80 moves from the use 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 use position to the retracted position, the amount of movement of the fixing device 80 in the direction perpendicular to the direction of movement of the tray unit 50 is greater than the amount of movement of the fixing device 80 in the direction parallel to the direction of movement of the tray unit 50.

[0075] Furthermore, the fixing device 80 may be attached to the device body 1A via a guide fixed to the device body 1A, and move between the operating position and the retracted position. In this case, the shape of the guide is arbitrary.

[0076] However, the method for moving the fixing device 80 outside the first space is not limited to this. For example, the fixing device 80 may be detachable from the main body 1A so as to be moved out of its operating position, thereby moving the fixing device 80 outside the first space. In other words, the fixing device 80 may be positioned outside the first space by separating it from the main body 1A and the door 20 (separating it from the main frame 100). Alternatively, the fixing device 80 may be connected to the door 20, and the fixing device 80 may be moved outside the first space by opening the door 20.

[0077] [Relationship between tray unit and transfer unit] The relationship between the tray unit 50 and the transfer unit 40 will be explained using Figures 1, 2, 3, 4, 5, 6, and 7.

[0078] When the fixing device 80 is in the position shown in Figure 2, the tray handle 52 is hidden by the fixing device 80 and cannot be grasped. When the fixing device 80 is located outside the first space, as shown in Figure 3, the user can grasp the tray handle 52 of the tray unit 50 and move it toward the outside of the device body 1A.

[0079] As shown in Figures 6 and 7, the position of the transfer unit 40 when the image forming operation is performed on the sheet S has the following relationship with the first space.

[0080] In other words, when the image forming operation is performed on the sheet S, the transfer unit 40 is in the second inner position. As shown in Figures 6 and 7, at least a portion of the transfer unit 40 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 inside the first space.

[0081] In this embodiment, at least a portion of the transfer unit 40 overlaps with the space through which the tray 51 passes when the tray unit 50 moves from the first inner position to the first outer position, but it may also be arranged to overlap with the space through which the cartridge P passes. This makes it possible to miniaturize the main body 1A of the device compared to a configuration in which the transfer unit 40 in the second inner position is located outside the first space.

[0082] In this embodiment, the printer 1 is such that the part of the transfer unit 40 that overlaps the first space is the cleaning section 43 that houses the cleaning member 43A. However, other parts of the transfer unit 40 may overlap the first space. Also, in this embodiment, the cleaning member 43A of the transfer unit 40 located in the second inner position overlaps the first space.

[0083] 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 part of the transfer unit 40 (cleaning part 43) is downstream of the tray unit 50 in the direction of movement when the tray unit 50 moves from the first inner position to the first outer position. Also, in the vertical direction V, the area (range) where the part of the transfer unit 40 (cleaning part 43) downstream of the tray unit 50 is located at least partially overlaps with the area (range) where the tray unit 50 is located.

[0084] In this embodiment, when the door 20 is closed, at least a portion of the double-sided transport path 20a overlaps with the second space through which the transfer unit 40 passes when moving 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 transport path 20a is inside the second space.

[0085] As described above, when the transfer unit 40 is in the second inner position, at least a portion of the transfer unit 40 is inside the first space. Therefore, in this embodiment, when the user moves the tray unit 50 from the first inner position to the first outer position relative to the device body 1A, the transfer unit 40 also moves from the second inner position to the second outer position relative to the device body 1A. In other words, with the transfer unit 40 and the tray unit 50 integrated, the tray unit moves from the first inner position to the first outer position, and the transfer unit 40 moves from the second inner position to the second outer position.

[0086] By moving the tray unit 50 and the transfer unit 40 together, exposure of the photosensitive drum 61 is suppressed when the tray unit 50 moves to the first outer position, thereby preventing scratches and dirt from getting on the photosensitive drum 61.

[0087] As shown in Figure 7, when the door 20 is open, the tray unit 50 is in the first outer position, and the transfer unit 40 is in the second outer position, the transfer unit 40 supports the tray unit 50 from below. Furthermore, in this embodiment, the door 20 supports the transfer unit 40. In other words, the transfer unit 40, supported by the door 20, supports the tray unit 50. This state can also be described as the door 20 supporting the tray unit 50 via the transfer unit 40.

[0088] Figures 8, 9, and 10 illustrate the configuration for moving the tray unit 50 and the transfer unit 40 as a single unit. Figures 8, 9, and 10 illustrate the connecting members (levers, stoppers, locking members) 53 that connect the tray 51 of the tray unit 50 and the transfer unit 40.

[0089] The printer 1 according to this embodiment has a locking member 53. In this embodiment, the locking member 53 is provided on the tray 51 of the tray unit 50. The locking member 53 is for transfer It has a locking part 53A and is rotatable around the rotation center 53B.

[0090] The tray 51 is equipped with a transfer coupling section 51A. The transfer unit 40 is equipped with a transfer frame 48 that supports a drive roller 46, a tension roller 47, and a primary transfer roller 42, and the transfer frame 48 is provided with a tray coupling groove 48A and a lock coupling section 48B.

[0091] The locking member 53 can move between a connected position where the transfer locking portion 53A engages with the locking connecting portion 48B and the transfer unit 40 and the tray unit 50 are connected, and a released position where it is retracted from the connected position, by rotating around the rotation center 53B.

[0092] When the transfer connecting portion 51A engages with the tray connecting groove 48A, the tray unit 50 is restricted from moving in the first removal direction Dd1 (pull-out direction) and in the direction perpendicular to the first removal direction Dd1 relative to the transfer unit 40. On the other hand, the transfer unit 40 is restricted from moving in the second mounting direction Da2 and in the direction perpendicular to the second mounting direction Da2 relative to the tray unit 50.

[0093] Similar configurations are provided in a total of four locations: near both ends of the tension roller 47 in the direction of its rotation axis, and near both ends of the drive roller 46 in the direction of its rotation axis.

[0094] When the transfer lock portion 53A of the locking member 53 at the connection position engages with the locking connection portion 48B, the tray unit 50 is restricted from moving in the first mounting direction Da1 (insertion direction) relative to the transfer unit 40. On the other hand, the transfer unit 40 is restricted from moving in the second removal direction Dd2 relative to the tray unit 50.

[0095] The locking member 53 and the locking connecting portion 48B may also be provided at both ends of the transfer unit 40 in the direction of the rotation axis of the tension roller 47.

[0096] In other words, when the transfer connecting portion 51A engages with the tray connecting groove 48A, and the locking member 53 at the connecting position engages with the locking connecting portion 48B, the transfer unit 40 and the tray unit 50 are restricted from moving relative to each other. In this state, there may be some play between the transfer unit 40 and the tray unit 50.

[0097] In other words, the transfer coupling portion 51A and the locking member 53 function as a tray-side coupling device, and the tray coupling groove 48A and the locking coupling portion 48B function as a transfer-side coupling device. By connecting the tray-side coupling device and the transfer-side coupling device, the tray unit 50 and the transfer unit 40 are connected, and the tray unit 50 and the transfer unit 40 move as a single unit.

[0098] On the other hand, as shown in Figure 9, the main body of the device 1A has a connecting shaft 581 with a circular cross-section that is positioned perpendicular 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 is in contact with the connecting shaft 581 and is in the released position. In this state, the transfer locking part 53A is separated from the locking connecting part 48B.

[0099] With the locking member 53 in the released position, when the tray unit 50 is moved in the first removal direction Dd1, the transfer unit 40 is pushed toward the second removal direction Dd2 by the transfer coupling part 51A. As a result, the transfer unit 40 is also moved toward the second removal direction Dd2 together with the tray unit 50. When the tray unit 50 has moved a predetermined distance in the first removal direction Dd1, the locking member 53 separates from the coupling shaft 581 and moves to the coupling position, locking... The locking member 53 engages with the locking connector 48B. With the locking member 53 in the connection position and engaged with the locking connector 48B, the tray unit 50 is moved to the first outer position and the transfer unit 40 is moved to the second outer position.

[0100] When the tray unit 50 is moved in the first mounting direction Da1 with the locking member 53 engaged with the locking connecting portion 48B, the transfer unit 40 is pushed toward the second mounting direction Da2 by the locking member 53. As a result, the transfer unit 40 is also moved toward the second mounting direction Da2 together with the tray unit 50.

[0101] When the transfer unit 40 is moved in the second mounting direction Da2 with the locking member 53 engaged with the locking connecting portion 48B, the transfer unit 40 pushes the transfer connecting portion 51A, and the tray unit 50 is pushed toward the first mounting direction Da1. As a result, the tray unit 50 is also moved toward the first mounting direction Da1 together with the transfer unit 40.

[0102] When the tray unit 50 and the transfer unit 40 are moved together toward the inside of the device body 1A, the locking member 53 is moved to the release position by the connecting shaft 581. In this state, even if the tray unit 50 is moved in the first mounting direction Da1, the transfer unit 40 does not move. Therefore, in the process of closing the door 20, the force of the secondary transfer roller 45 contacting the transfer unit 40 pushes the transfer unit 40 toward the second mounting direction Da2, pushing it to the back of the device body 1A (second inner position). In other words, the door 20 can push the transfer unit 40 so that it is positioned in the second inner position. Alternatively, the door 20 may push the tray unit 50 so that it is positioned in the first inner position.

[0103] On the other hand, when the locking member 53 is in the released position and the tray unit 50 is in the first inner position, moving the transfer unit 40 in the second removal direction Dd2 allows the transfer unit 40 to move independently from the tray unit 50 from the second inner position to the second outer position. In the printer 1 of this embodiment, as shown in Figure 5, with the tray unit 50 positioned inside the device body 1A (first inner position), the transfer unit 40 can be moved to the outside of the device body 1A (second outer position). The transfer unit 40 is removable from the device body 1A and can be replaced with a new transfer unit 40.

[0104] In this embodiment, when the tray unit 50 is in the first inner position, the tray unit 50 is positioned relative to the device body 1A. Furthermore, when the transfer unit 40 is in the second inner position, the clearance between the tray connecting groove 48A and the transfer connecting portion 51A is eliminated so that the transfer unit 40 can be positioned accurately relative to the tray unit 50.

[0105] When the tray unit 50 is in the first inner position and the transfer unit 40 is in the second inner position, if it is desired to position the tray unit 50 and the transfer unit 40 independently relative to the device body 1A, a clearance should be provided between the tray connecting groove 48A and the transfer connecting part 51A.

[0106] [Movement of tray unit and transfer unit] As shown in Figures 1, 6, and 7, the tray unit 50 and the transfer unit 40 are tilted with respect to the horizontal direction H when mounted on the main body 1A of the device.

[0107] More specifically, when the tray unit 50 is in the first inner position, the rotation axis of the photosensitive drum 61 closer to the first end 1b1 is located higher in the vertical direction V than the rotation axis of the photosensitive drum 61 further from the first end 1b1.

[0108] In other words, with the tray unit 50 in the first inner position, the second photosensitive drum is closer to the first end 1b1 than the first photosensitive drum, and the rotation axis of the second photosensitive drum is located vertically V above the rotation axis of the first photosensitive drum. Similarly, the third photosensitive drum is closer to the first end 1b1 than the second photosensitive drum, and the rotation axis of the third photosensitive drum is located vertically V above the rotation axis of the second photosensitive drum. The fourth photosensitive drum is closer to the first end 1b1 than the third photosensitive drum, and the rotation axis of the fourth photosensitive drum is located vertically V above the rotation axis of the third photosensitive drum.

[0109] Here, as shown in Figure 1, when viewed in the direction of the rotation axis of the photosensitive drum 61, the straight line connecting the centers of each photosensitive drum 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 with respect to the horizontal direction H, from the side farther from the first end 1b1 towards the side closer to the first end 1b1. Furthermore, the contact surfaces of the belt 41 that contact the first photosensitive drum, the second photosensitive drum, the third photosensitive drum, and the fourth photosensitive drum are inclined upward, from the side farther from the first end 1b1 towards the side closer to the first end 1b1.

[0110] When the tray unit 50 moves from the first inner position to the first outer position, the tray unit 50 moves in a direction inclined with respect to the horizontal direction H (in this embodiment, in a direction inclined upward with respect to the horizontal direction H). In other words, when the tray unit 50 moves from the first inner position to the first outer position, the tray unit 50 moves diagonally upward. 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 diagonally upward to downward. The direction of movement of the tray unit 50 may include a direction parallel to the horizontal direction H, or a direction diagonally downward with respect to the horizontal direction H.

[0111] The angle between the straight line LD and the horizontal direction H is smaller when the tray unit 50 is in the first outer position than when the tray unit 50 is in the first inner position. In this embodiment, when the tray unit 50 is in the first outer position, the straight line LD and the horizontal direction H are parallel, but the straight line LD may be inclined downward or upward with respect to the horizontal direction H.

[0112] 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 diagonally upward to downward. The direction of movement of the transfer unit 40 may include a direction parallel to the horizontal direction H, or a diagonally downward direction relative to the horizontal direction H.

[0113] The angle between the contact surface of the belt 41 and the horizontal direction H is smaller when the transfer unit 40 is in the second outer position than when the transfer unit 40 is in the second inner position. In this embodiment, when the transfer unit 40 is in the second outer position, the contact surface of the belt 41 is parallel to the horizontal direction H, but the contact surface of the belt 41 may be inclined downward or upward with respect to the horizontal direction H.

[0114] When moving the tray unit 50 from the first outer position to the first inner position, the tray unit 50 moves horizontally in the H direction, and then moves diagonally downward from a certain point. When moving the transfer unit 40 from the second outer position to the second inner position, the transfer unit 40 moves horizontally in the H direction, and then moves diagonally downward from a certain point. With this configuration, when inserting the tray unit 50 and the transfer unit 40 into the device body 1A, the weight of the tray unit 50 and the transfer unit 40 can be utilized.

[0115] [Positioning of the tray unit] Figures 9, 10, 11, and 12 will be used to explain the positioning method of the tray unit 50 relative to the device body 1A. Here, Figure 9 shows the position of the tray unit 50 on the front (downstream) side in the insertion direction of the tray unit 50 in the positioning configuration of the tray unit 50 relative to the device body 1A. This is also a cross-sectional view to explain the fixed configuration. Figure 11 is a side view to explain the positioning configuration of the tray unit 50 on the rear (upstream) side in the insertion direction of the tray unit 50 relative to the main body 1A of the device. Figure 12 is a schematic diagram that shows the planar configuration of the left and right side frames of the main body 1A and the tray unit 50 when viewed in a direction perpendicular to both the insertion / removal direction of the tray unit 50 relative to the main body 1A and the rotation axis direction of the photosensitive drum, etc. Note that in Figure 10, the configurations of the main body 1A and the tray unit 50 are illustrated so that the insertion direction Da1 to the withdrawal direction Dd1 is horizontal. When the printer 1 is installed on a horizontal plane as is normally assumed, the insertion direction Da1 is inclined downward from the upstream side to the downstream side.

[0116] As shown in Figure 12, the frame constituting the main body 1A of the device includes a left side frame 100L and a right side frame 100R. The left side 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 engaging 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. As a result, the position of the tray unit 50 is restricted in a direction perpendicular to the direction of movement of the tray unit 50. In other words, the engagement of the first engaging portion F1 and the first engaged portion F2, and the second engaging portion R1 and the second engaged portion R2 restricts the relative movement between the device body 1A and the tray unit 50 in the width direction W intersecting the insertion / removal direction.

[0117] As shown in Figure 12, a connecting shaft 581 is positioned on the second end 1b2 side of the main body 1A of the device so as to connect the left side frame 100L and the right side frame 100R. The connecting shaft 581 is a shaft with a circular cross-section that extends in a direction intersecting (orthogonal in this embodiment) the direction of movement of the tray unit 50, and is provided to rotate freely with respect to the left side frame 100L and the right side frame 100R. When the tray unit 50 is mounted on the main body 1A of the device, the connecting shaft 581 is configured to engage with an engaged portion provided on the tray unit 50 as an engaging portion provided on the main body 1A of the device.

[0118] The engaging and engaged parts described above will be explained with reference to Figures 9 and 10. Here, Figures 9 and 10 show the configuration of the engaging and engaged parts on the right side in the width direction W of the device body 1A and the tray unit 50, and engaging and engaged parts are also provided on the opposite left side, configured symmetrically in the width direction W. However, engaging and engaged parts may be provided on either the right or left side in the width direction.

[0119] As shown in Figures 9 and 10, the front end side (rear end side in the pulling-out direction) of the tray unit 50 in the mounting direction is provided with a first contact portion 541 and a second contact portion 551, which constitute a positioning portion 502R for positioning the tray unit 50 on the device body 1A. The first contact portion 541 and the second contact portion 551 are configured to be able to contact the connecting shaft 581 of the device body 1A. The connecting shaft 581 is positioned closer to the front end (downstream end) of the tray unit 50 than to the rear end (upstream end) in the mounting direction (insertion direction) of the tray unit 50 when the tray unit 50 is in the mounting position. The front end side of the tray unit 50 in the mounting direction is further provided with a third contact portion 561 for defining the limit position of the movement of the tray unit 50 on the device body 1A in the mounting direction. The third contact portion 561 is also configured to be able 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 these positioning portions 502 constitute the engaged portion of the tray unit 50, to which the connecting shaft 581 of the device body 1A, which acts as an engaging portion, can engage.

[0120] The tray unit 50 is located on the right side of the tray facing the right side frame 100R of the main body 1A of the device. The tray has a frame 500R, and the right frame 500R of the tray is provided with a guide groove 501R that is recessed in the opposite direction to the mounting direction (pull-out direction). When the tray unit 50 is inserted into the device body 1A to the mounting position, the connecting shaft 581 of the device body 1A is inserted into the guide groove 501R along the insertion / removal direction. The positioning portion 502R, consisting of a first contact portion 541 and a second contact portion 551, and the third contact portion 561 are part of the groove forming portion that forms the guide groove 501R.

[0121] When the tray unit 50 is mounted on the device body 1A, the upper surface 504R, which is a surface area facing approximately downwards in the guide groove 501R, rests on the connecting shaft 581, so that the leading edge of the tray unit 50 in the insertion direction is supported by the connecting shaft 581. The positioning portion 502, including the first contact portion 541 and the second contact portion 551, is provided as a downward-facing concave shape on the upper surface 504R of the guide groove 501R. During the process of mounting the tray unit 50 on the device body 1A, the upper surface 504R moves smoothly along the connecting shaft 581, and the connecting shaft 581 fits into the downward-facing concave shape of the positioning portion 502. In this embodiment, since the connecting shaft 581 is rotatably provided on the device body 1A, the relative movement between the connecting shaft 581 and the guide groove 501R during insertion of the tray unit 50 is smooth.

[0122] The first contact portion 541 is configured to restrict the movement of the tray unit 50 in the mounting direction (insertion direction) relative to the device body 1A by contacting the connecting shaft 581. When the tray unit 50 is mounted on the device body 1A, the first contact portion 541 is configured as a first inclined surface that is inclined with respect to the insertion / removal direction of the tray unit 50 relative to the device body 1A. The direction in which the first inclined surface, the first contact portion 541, extends is a direction that intersects both the horizontal direction and the direction of gravity. The direction (normal direction) that the first inclined surface, the first contact portion 541, faces is a direction that includes the component of the insertion direction (Da1) of the tray unit 50 relative to the device body 1A.

[0123] The second contact portion 551 is configured to contact the connecting shaft 581, thereby restricting the movement of the tray unit 50 in the direction opposite to the mounting direction to the device body 1A (movement in the pulling direction). When the tray unit 50 is mounted on the device body 1A, the second contact portion 551 is configured as a second inclined surface that is inclined with respect to the insertion / removal direction of the tray unit 50 to the device body 1A. The direction in which the second inclined surface, the second contact portion 551, extends is a direction that intersects both the horizontal direction and the direction of gravity. The direction that the second inclined surface, the second contact portion 551, faces (normal direction) is a direction that includes the component of the pulling direction (Dd1) of the tray unit 50 to the device body 1A.

[0124] When the first contact portion 541 and the second contact portion 551 of the tray unit 50 are simultaneously in contact with the connecting shaft 581 of the device body 1A, the tray unit 50 is positioned horizontally H relative to the device body 1A. When the first contact portion 541 and the second contact portion 551 of the tray unit 50 are simultaneously in contact with the connecting shaft 581 of the device body 1A, the tray unit 50 is positioned vertically V relative to the device body 1A. When the first contact portion 541 and the second contact portion 551 of the tray unit 50 are simultaneously in contact with the connecting shaft 581 of the device body 1A, the tray unit 50 is positioned in the insertion direction Da1, the withdrawal direction Dd1, and directions perpendicular to these relative to the device body 1A. When the first contact portion 541 and the second contact portion 551 of the tray unit 50 are simultaneously in contact with the connecting shaft 581 of the device body 1A, the tray unit 50 is in the positioning position (mounting position).

[0125] The third contact portion 561 is located at the innermost part of the guide groove 501R, upstream of the first contact portion 541 and the second contact portion 551 in the insertion direction of the tray unit 50. The third contact portion 561 is connected to both the first contact portion 541 and the second contact portion 551. The third contact portion 561 is positioned so as not to come into contact with the connecting shaft 581 when it is in contact with the shaft 581 (positioned by the positioning portion 502R). The width of the guide groove 501R in the direction intersecting the insertion / removal direction of the tray unit 50 (mounting direction and pulling direction) has a predetermined amount of play relative to the width of the cross-section of the connecting shaft 581 in the same direction. Therefore, for example, if the tray unit 50 is inserted with momentum, it is possible to insert the tray unit 50 in such a way that the connecting shaft 581 goes beyond the positioning position (mounting position) set by the positioning portion 502R and into the back of the guide groove 501R. When the connecting shaft 581 goes beyond the positioning position set by the positioning portion 502R and into the back of the guide groove 501R and reaches the restricted position, the third contact portion 561 comes into contact with the connecting shaft 581, restricting the insertion of the tray unit 50. In other words, the contact of the third contact portion 561 with the connecting shaft 581 defines the limit position of movement of the tray unit 50 in the mounting direction relative to the device body 1A. When the tray unit 50 is in the restricted position where the third contact portion 561 contacts the connecting shaft 581, if there is no external force pushing the tray unit 50 in the mounting direction, the state in which the third contact portion 561 contacts the connecting shaft 581 is not maintained. Specifically, the tray unit 50 is configured to return to the position where it is positioned by the positioning portion 502R due to its own weight. In this embodiment, as the return portion, there is a series of downwardly sloping surfaces extending from the third contact portion 561 to the first contact portion 541 of the positioning portion 502R. As the inclined surface slides along the connecting shaft 581, the connecting shaft 581 is positioned in the positioning section 502R (in contact with both the first contact section 541 and the second contact section 551), that is, the tray unit 50 automatically returns to the positioning position.

[0126] Figures 18(a) and 18(b) are schematic diagrams showing a simplified configuration of the engaging and engaged parts in this embodiment. Figure 18(a) shows the state when the third contact part 561, which serves as a restricting part and is provided on the tray unit 50, contacts the connecting shaft 581, which serves as an engaging part and is provided on the device body 1A, and the tray unit 50 is in the restricted position. Figure 18(b) shows the state when the first contact part 541 and the second contact part 551, which constitute the engaged part and are provided on the tray unit 50, contact the connecting shaft 581, which serves as an engaging part and is provided on the device body 1A, and the tray unit 50 is in the mounting position (positioning position). As shown in Figures 18(a) and 18(b), the connecting shaft 582 has a first contacted portion 91 that contacts the first contacted portion 541, a second contacted portion 92 that contacts the second contacted portion 551, and a third contacted portion 93 that contacts the third contacted portion 561.

[0127] As shown in Figure 18(a), when the tray unit 50 is inserted further downstream in the insertion direction beyond the mounting position (positioning position), the third contact portion 561 of the tray unit 50 comes into contact with the connecting shaft 581 of the device body 1A, restricting the movement of the tray unit 50 in the insertion direction. At this time, the connecting shaft 581 is at least away from the second contact portion 551, and in this embodiment, the connecting shaft 581 is away from both the first contact portion 541 and the second contact portion 551. Also at this time, the inclined surface 511 of the tray unit 50 comes into contact with the connecting shaft 581, which supports the leading end of the tray unit 50 in the insertion direction, in the direction of gravity. The inclined surface 511 is an inclined surface that extends in a direction intersecting both the horizontal direction and the direction of gravity when in contact with the connecting shaft 581. Therefore, when there is no external force acting on the tray unit 50 (excluding gravity), the tray unit 50 will no longer maintain the state in which the third contact portion 561 is in contact with the connecting shaft 581, and the inclined surface 511 will slide along the connecting shaft 581 due to its own weight, returning to the mounting position (positioning position). In other words, as shown in Figure 18(b), both the first contact portion 541 and the second contact portion 551 will be in contact with the connecting shaft 581. Thus, the inclined surface 511 functions as a return portion.

[0128] In the configuration example shown in Figures 18(a) and 18(b), the inclined surface 511, which serves as the return section, is a continuous inclined surface with the first contact section 541, and the first contact section 541 and the inclined surface 511 are arranged in a straight line. However, the relationship between the first contact section 541 and the inclined surface 511 is such that It is not limited to these. For example, the inclined surface 511 may be configured as an inclined surface that is separate (discontinuous) from the first contact portion 541, the inclination angle may be different from that of the first contact portion 541, and the surface may bend or curve in the middle. In other words, various configurations can be adopted as long as they can function as a return portion that moves the tray unit 50 from the restricted position to the mounting position using its own weight.

[0129] As shown in Figure 12, the tray unit 50 also has a tray left frame 500L that faces the left side frame 100L of the device body 1A. Although not shown in the figure, the tray left frame 500L is provided with an engaged portion that has the same configuration as the engaged portion of the tray right frame 500R, which consists of a positioning portion 502R (first contact portion 541, second contact portion 551) and a third contact portion 561.

[0130] As shown in Figures 11 and 12, a tray shaft 591 is provided on the side of the tray unit 50 closest to the tray handle 52, which serves as the gripping portion, extending outward from the left side frame 100L and the right side frame 100R of the device body 1A. The tray shaft 591 is positioned closer to the rear end (upstream end) of the tray unit 50 than to the front end (downstream end) in the mounting direction (insertion direction) of the tray unit 50 when the tray unit 50 is in the mounting position. Fourth contact portions 571L and 571R are provided on the left side frame 100L and the right side frame 100R of the device body 1A. The fourth contact portions 571L and 571R are part of guide grooves provided on the left side frame 100L and the right side frame 100R, respectively, which guide the tray shaft 591 in the insertion and removal direction of the tray unit 50.

[0131] Figure 11 shows the guide groove 573L of the left side frame 100L. The guide groove 573L is configured as a groove shape that extends in the insertion and removal direction of the tray unit 50 and has a lower surface area 574L which is a surface area facing approximately upward. When the tray unit 50 is mounted on the device body 1A, the tray shaft 591 rests on the lower surface area 574L, so that the rear end of the tray unit 50 in the insertion direction is supported by the guide groove 573L (lower surface area 574L). The fourth contact portion 571L is configured as part of the lower surface area 574L of the guide groove 573L. The right side frame 100R is also provided with a guide groove 573R with a similar configuration. The tray shaft 591 of the tray unit 50 abuts against the fourth contact portions 571L and 571R of the left side frame 100L and the right side frame 100R, respectively. This restricts the movement of the tray unit 50 in a direction intersecting the insertion direction of the tray shaft 591 relative to the guide groove 573L. Thus, the tray unit 50 is positioned vertically V (in the direction of gravity) relative to the device body 1A. The tray shaft 591 has a circular cross-section and is a single shaft member that passes through the tray unit 50.

[0132] When the tray unit 50 is positioned at the leading end in the mounting direction by the connecting shaft 581 of the device body 1A, the tray shaft 591 is positioned at the rear end in the mounting direction by contacting the fourth contact portions 571L and 571R. 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 to the point where the third contact portion 561 contacts the connecting shaft 581 at the leading end in the mounting direction, the tray shaft 591 does not come into contact with the far end of the guide groove 573L.

[0133] With the above configuration, the tray unit 50 is positioned relative to the main body 1A of the device.

[0134] Here, the state in which both the first contact portion 541 and the second contact portion 551 are in contact with the connecting shaft 581 corresponds to the state in which the tray unit 50 is in a predetermined mounting position relative to the device body 1A, and the printer 1 is in a state in which it can perform image forming operations. The third contact portion 561 is not configured to be directly involved in the positioning of the tray unit 50 during the image forming operation, and therefore may deform (wear) due to repeated pulling out and mounting or forceful mounting. Even if this occurs, it is possible to suppress the impact on the positioning accuracy of the tray unit 50.

[0135] In this embodiment, the connecting shaft 581 is a single shaft member with a circular cross-section that connects the left side frame 100L and the right side frame 100R, but the same effect can be obtained even if the shaft shape is not circular in cross-section.

[0136] In this embodiment, the first contact portion 541 and the second contact portion 551 constituting the positioning portion 502 are configured as linear inclined surfaces. The angle formed by the first contact portion 541 and the second contact portion 551 can be arbitrarily set based on the angle of the tray unit 50 relative to the device body 1A and its own weight. The configuration of the positioning portion 502 is not limited to the configuration of this embodiment; for example, the same effect as in this embodiment can be obtained even if the first contact portion 541 and the second contact portion 551 are configured as curved surfaces.

[0137] In this embodiment, the third contact portion 561 of the tray unit 50 is abutted against the connecting shaft 581 of the device body 1A to restrict excessive insertion of the tray unit 50, but the configuration is not limited to this. For example, instead of the third contact portion 561 of the tray unit 50, the device body 1A may be provided with a third contact portion. The third contact portion may abut against a part other than the connecting shaft 581, as long as the function of restricting excessive insertion of the tray unit 50 is obtained and the return portion functions. <Example 2> Using Figures 12 to 15, the method for positioning the tray unit 50 relative to the apparatus body 1A in the image forming apparatus according to Embodiment 2 of the present invention will be explained. In this embodiment, components common to Embodiment 1 are denoted by the same reference numerals, and components different from Embodiment 1 will be mainly described. In this embodiment, matters not specifically described here are the same as in Embodiment 1.

[0138] In Example 1, the positioning configuration for the tray unit 50 in the insertion and removal direction, consisting of an engaging portion and an engaged portion, was positioned on the front side of the tray unit 50 in the insertion direction, while the positioning configuration for the tray unit 50 in the vertical direction V (direction of gravity) was positioned on the rear side of the tray unit 50 in the insertion direction. In contrast, in Example 2, the positioning configuration for the tray unit 50 in the insertion and removal direction, consisting of an engaging portion and an engaged portion, was positioned on the rear side of the tray unit 50 in the insertion direction, while the positioning configuration for the tray unit 50 in the vertical direction V (direction of gravity) was positioned on the front side of the tray unit 50 in the insertion direction.

[0139] Furthermore, in Example 1, the engaging portion was provided on the main body 1A of the device, and the engaged portion was provided on the tray unit 50. In contrast, in Example 2, the engaging portion was provided on the tray unit 50, and the engaged portion was provided on the main body 1A of the device.

[0140] As shown in Figure 12, the main body of the device 1A includes a left side frame 100L and a right side frame 100R. The left side frame 100L includes a first engaging portion F1 and a second engaging portion R1 that can restrict the position of the tray unit 50 perpendicular to the direction of movement.

[0141] As shown in Figures 13 and 14, a tray shaft 591 is provided on the side of the tray unit 50 closest to the tray handle 52, extending outwards from the left side frame 100L and the right side frame 100R. The tray shaft 591 has a circular cross-section and is a single shaft member that penetrates the tray unit 50. The tray shaft 591 constitutes an engaging portion provided on the tray unit 50. The left side frame 100L and the right side frame 100R are each provided with a first contact portion 542 that restricts the movement of the tray unit 50 in the mounting direction and a second contact portion 552 that restricts movement in the opposite direction to the mounting direction. These first contact portion 542 and second contact portion 552 constitute a positioning portion 508 (see Figure 19) for positioning the tray unit 50 relative to the device body 1A. Furthermore, the left side frame 100L and the right side frame 100R are provided with a third contact portion 562 to define the limit position of movement of the tray unit 50 in the mounting direction relative to the device body 1A. Positioning portion 508 The first contact portion 542, the second contact portion 552, and the third contact portion 562 constitute the engaged portion of the device body 1A, to which the tray shaft 591 of the tray unit 50, which acts as an engaging portion, can engage.

[0142] Figure 14 shows the guide groove 575L of the left side frame 100L. The guide groove 575L is configured as a groove shape that extends in the insertion and removal direction of the tray unit 50 and has a lower surface area 576L which is a surface area facing approximately upward. When the tray unit 50 is mounted on the device body 1A, the tray shaft 591 rests on the lower surface area 576L, so that the rear end of the tray unit 50 in the insertion direction is supported by the guide groove 575 (lower surface area 576L). The positioning portion 508, including the first contact portion 542 and the second contact portion 552, is provided as an upward-facing concave shape that is recessed downward on the lower surface area 576L of the guide groove 575L. During the process of mounting the tray unit 50 on the device body 1A, the tray shaft 591 moves so as to slide along the lower surface area 576R, and the tray shaft 591 fits into the positioning portion which is a concave shape. In this embodiment, since the tray shaft 591 is rotatably mounted on the tray unit 50, the relative movement between the tray shaft 591 and the guide groove 575L during insertion of the tray unit 50 is smooth.

[0143] The first contact portion 542 is configured to restrict the movement of the tray unit 50 in the mounting direction (insertion direction) relative to the device body 1A by contacting the tray shaft 591. The first contact portion 542 is configured as a first inclined surface that is inclined with respect to the insertion / removal direction of the tray unit 50 relative to the device body 1A. The direction in which the first inclined surface, the first contact portion 542, extends is a direction that intersects both the horizontal direction and the direction of gravity. The direction (normal direction) that the first inclined surface, the first contact portion 542, faces is a direction that includes the component of the withdrawal direction (Dd1) of the tray unit 50 relative to the device body 1A.

[0144] The second contact portion 552 is configured to contact the tray shaft 591, thereby restricting the movement of the tray unit 50 in the direction opposite to the mounting direction to the device body 1A (movement in the pulling direction). The second contact portion 552 is configured as a second inclined surface that is inclined with respect to the insertion / removal direction of the tray unit 50 to the device body 1A. The direction in which the second inclined surface, the second contact portion 552, extends is a direction that intersects both the horizontal direction and the direction of gravity. The direction that the second inclined surface, the second contact portion 552, faces (normal direction) is a direction that includes the component of the insertion direction (Da1) of the tray unit 50 to the device body 1A.

[0145] When the tray shaft 591 of the tray unit 50 is simultaneously in contact with both the first contact portion 542 and the second contact portion 552 of the device body 1A, the tray unit 50 is positioned in the horizontal direction H relative to the device body 1A. When the tray shaft 591 of the tray unit 50 is simultaneously in contact with both the first contact portion 542 and the second contact portion 552 of the device body 1A, the tray unit 50 is positioned in the vertical direction V relative to the device body 1A. When the tray shaft 591 of the tray unit 50 is simultaneously in contact with both the first contact portion 542 and the second contact portion 552 of the device body 1A, the tray unit 50 is positioned in the insertion direction Da1, the withdrawal direction Dd1, and directions perpendicular to these relative to the device body 1A. When the tray shaft 591 of the tray unit 50 is simultaneously in contact with both the first contact portion 542 and the second contact portion 552 of the device body 1A, the tray unit 50 is in the positioning position (mounting position).

[0146] The third contact portion 562 is located at the innermost part of the guide groove 575L, downstream of the first contact portion 542 and the second contact portion 552 in the insertion direction of the tray unit 50. The third contact portion 562 is located in a position where the tray shaft 591 does not contact the first contact portion 542 and the second contact portion 552 when the tray shaft 591 is in contact with both the first contact portion 542 and the second contact portion 552 (positioned by the positioning portion 508). The width of the guide groove 575L in the direction intersecting the insertion and removal direction (mounting direction and pulling direction) of the tray unit 50 is such that the width of the tray shaft 591 The cross-section is configured to have a predetermined amount of play in the same direction. Therefore, for example, if the tray unit 50 is inserted with momentum, it is possible to insert the tray unit 50 such that the tray shaft 591 goes beyond the positioning position (mounting position) set by the positioning part 508 and is inserted into the back of the guide groove 575L. When the tray shaft 591 goes beyond the positioning position set by the positioning part 508 and is inserted into the back of the guide groove 575L and reaches the restricted position, the tray shaft 591 comes into contact with the third contact part 562, and the insertion of the tray unit 50 is restricted. In other words, the contact of the third contact part 562 with the tray shaft 591 defines the limit position of movement of the tray unit 50 in the mounting direction relative to the device body 1A.

[0147] When the tray unit 50 is in a restricted position where the tray shaft 591 is in contact with the third contact portion 562, if the external force pushing the tray unit 50 in the mounting direction is removed, the state in which the tray shaft 591 is in contact with the third contact portion 562 is not maintained. Specifically, the tray unit 50 is configured to return to the position where it is positioned in the positioning portion 508 due to its own weight. In this embodiment, the return portion consists of a series of inclined surfaces that slope downward from the third contact portion 562 to the first contact portion 542 of the positioning portion 508. As the tray shaft 591 slides along these inclined surfaces, the tray shaft 591 automatically returns to the position where it fits into the positioning portion 508 (in contact with both the first contact portion 542 and the second contact portion 552), that is, to the positioning position.

[0148] Figures 19(a) and 19(b) are schematic diagrams showing a simplified configuration of the engaging and engaged parts in this embodiment. Figure 19(a) shows the tray shaft 591, which serves as an engaging part provided on the tray unit 50, in contact with the third contact part 562, which serves as a restricting part provided on the device body 1A, and the tray unit 50 is in the restricted position. Figure 19(b) shows the tray shaft 591, which serves as an engaging part provided on the device body 1A, in contact with the first contact part 542 and the second contact part 552, which constitute the engaged part provided on the tray unit 50, and the tray unit 50 is in the mounting position (positioning position). As shown in Figures 19(a) and 19(b), 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.

[0149] As shown in Figure 19(a), when the tray unit 50 is inserted further downstream in the insertion direction beyond the mounting position (positioning position), the tray shaft 591 of the tray unit 50 comes into contact with the third contact portion 562 of the device body 1A, restricting the movement of the tray unit 50 in the insertion direction. At this time, the tray shaft 591 is at least away from the second contact portion 552, and in this embodiment, the connecting shaft 581 is away from the first contact portion 542 and the second contact portion 552. Also at this time, the tray shaft 591 comes into contact with the inclined surface 512 of the guide groove 575L of the device body 1A that supports the rear end side of the tray unit 50 in the insertion direction, in the direction of gravity. The inclined surface 512 is an inclined surface that extends in a direction intersecting both the horizontal direction and the direction of gravity when the tray shaft 591 is in contact with it. Therefore, when there is no external force acting on the tray unit 50 (excluding gravity), the tray unit 50 will no longer maintain the state in which the tray shaft 591 is in contact with the third contact portion 562, and the tray shaft 591 will slide on the inclined surface 512 due to its own weight, returning to the mounting position (positioning position). That is, as shown in Figure 19(b), the tray shaft 591 will be in contact with both the first contact portion 542 and the second contact portion 552. In other words, the inclined surface 512 functions as a return portion.

[0150] In the configuration examples shown in Figures 19(a) and 19(b), the inclined surface 512, which serves as the return section, is a continuous inclined surface with the first contact section 542, and the first contact section 542 and the inclined surface 512 are arranged in a straight line. However, the relationship between the first contact section 542 and the inclined surface 512 is not limited to this relationship. For example, the inclined surface 512 may be separated (discontinuous) from the first contact section 542. It may be configured as an inclined surface, the inclination angle may be different from that of the first contact portion 542, and it may be a surface that bends or curves along the way. In other words, various configurations can be adopted as long as they can function as a return section that moves the tray unit 50 from the restricted position to the mounting position using its own weight.

[0151] Although not shown in the diagram, the right tray frame 500R is also provided with an engaged portion having the same configuration as the engaged portion on the left tray frame 500L, which consists of a positioning portion 508 (first contact portion 542, second contact portion 552) and a third contact portion 562.

[0152] As shown in Figures 12 and 15, a connecting shaft 581 is provided on the second end 1b2 side of the device body 1A to connect the left side frame 100L and the right side frame 100R. The tray unit 50 is provided with a fourth contact portion 572. When 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 guide groove 503R in the direction intersecting the insertion direction of the tray unit 50 relative to the connecting shaft 581 is restricted. Thus, 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 perpendicular to the direction of movement of the tray unit 50.

[0153] The tray unit 50 has a tray right frame 500R that faces the right side frame 100R of the device body 1A, and the tray right frame 500R is provided with a guide groove 503R that is recessed in the opposite direction to the mounting direction (pull-out direction). When the tray unit 50 is inserted into the device body 1A to the mounting position, the connecting shaft 581 of the device body 1A is inserted into the guide groove 503R along the insertion / removal direction. The guide groove 503R has an upper surface area 505R which is a surface area facing approximately downwards. When the tray unit 50 is mounted on the device body 1A, the upper surface area 505R rests on the connecting shaft 581, so that the tip of the tray unit 50 in the insertion direction is supported by the connecting shaft 581.

[0154] The fourth contact portion 572 is configured as part of the upper surface portion 505R of the guide groove 503R. The left tray frame 500L is also provided with a guide groove with the same configuration as the guide groove 503R of the right tray frame 500. The fourth contact portions 572 of the left side frame 100L and the right side frame 100R abut against the connecting shaft 581 of the device body 1A, thereby positioning the tray unit 50 in the vertical direction V (direction of gravity) relative to the device body 1A.

[0155] When the tray unit 50 is positioned at the rear end in the mounting direction by the positioning part of the device body 1A, the tray shaft 591 is positioned at the rear end in the mounting direction, and the fourth contact part 572 is positioned at the front end in the mounting direction by contacting the connecting shaft 581. 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 part 562 at the rear end in the mounting direction, the connecting shaft 581 does not come into contact with the far end of the guide groove 503R.

[0156] With the above configuration, the tray unit 50 is positioned relative to the main body 1A of the device.

[0157] Here, the state in which both the first contact portion 541 and the second contact portion 551 are in contact with the connecting shaft 581 corresponds to the state in which the tray unit 50 is in a predetermined mounting position relative to the device body 1A, and the printer 1 is in a state in which it can perform image forming operations. Since the third contact portion 562 is not configured to be directly involved in the positioning of the tray unit 50 during the image forming operation, wear that occurs due to repeated pulling out and mounting or forceful mounting can be suppressed from affecting the positioning accuracy of the tray unit 50.

[0158] On both sides of the tray handle 52 are sheet transport sections 52A, which extend from the drive rollers 46 of the transfer unit 40 to the fixing device 80. The drive rollers 46 and the fixing device 80 are positioned by the left side frame 100L and the right side frame 100R, similar to the tray shaft 591. As shown in Figure 1, the tray shaft 591, the transfer unit 40, and the fixing device 80 are close together, ensuring very high precision in their positioning.

[0159] This makes it easier to ensure the distance between the cartridge PY and the fixing device 80, which in turn makes it easier to manage the thermal effects of the fixing device 80 and enables stable sheet transport.

[0160] In this embodiment, the tray shaft 591 is a single shaft member with a circular cross-section that penetrates the tray unit 50, but the same effect can be obtained even if the shaft shape is not circular in cross-section.

[0161] In this embodiment, the first contact portion 542 and the second contact portion 552 constituting the positioning portion 505 are made of linear inclined surfaces, and the entire positioning portion 505 is made of a roughly V-shape. The angle at which the first contact portion 542 and the second contact portion 552 form the V-shape can be arbitrarily set based on the angle of the tray unit 50 with respect to the device body 1A and its own weight. The configuration of the positioning portion 505 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 made of curved surfaces, the same effect as in this embodiment can be obtained.

[0162] In this embodiment, the tray unit 50 is prevented from being inserted too far by abutting its tray shaft 591 against the third contact portion 562 of the device body 1A, but the configuration is not limited to this. The third contact portion may contact a part other than the tray shaft 591, as long as it provides the function of preventing excessive insertion of the tray unit 50 and the return portion functions correctly. <Example 3> Using Figures 9 to 12 and Figure 16, the method for positioning the tray unit 50 relative to the main body 1A of the apparatus in Example 3 will be explained. In this example, components common to Examples 1 and 2 are denoted by the same reference numerals, and components that differ from Examples 1 and 2 will be mainly described. In this example, matters not specifically described here are the same as in Examples 1 and 2.

[0163] Figure 16 is a perspective view illustrating the positioning configuration of the tray unit 50 at the insertion end of the device body 1A in this embodiment. A connecting shaft 582 is positioned on the second end 1b2 side of the device body 1A to connect the left side frame 100L and the right side frame 100R. As shown in Figure 16, the connecting shaft 582 has a non-circular engagement portion with the right side frame 100R. Specifically, the engagement portion with the right side frame 100R has a so-called D shape, including an arc portion and a flat portion (straight portion). That is, the connecting shaft 582 is configured not to rotate freely with respect to the right side frame 100R. Note that the right side frame 100R is not shown in Figure 16. Except for the non-circular engagement portion with the right side frame 100R, the connecting shaft 582 has a circular cross-section and extends in a direction perpendicular to the direction of movement of the tray unit 50.

[0164] The other configurations in Example 3 are the same as those in Example 1.

[0165] In Example 3, since the connecting shaft 582 is not rotatable, the surface that abuts against the third contact portion 561 is always the same.

[0166] As shown in Figures 18(a) and 18(b), 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. If the connecting shaft 582 does not rotate, the first contact portion 5 Neither 41 nor the second contact portion 551 comes into contact with the third contacted portion 93, and the third contact portion 561 comes into contact with neither the first contacted portion 91 nor the second contacted portion 92.

[0167] Therefore, even if the connecting shaft 582 wears down due to repeated pulling out and attaching of the tray unit 50 or forceful attachment, it does not affect the surface of the connecting shaft 582 that contacts the first contact portion 541 and the second contact portion 551. In other words, the areas of the connecting shaft 582 that contact the first contact portion 541, the second contact portion 551, and the third contact portion 561 are always different areas because the rotation of the connecting shaft 582 is restricted. Therefore, even if wear occurs in the area of ​​the connecting shaft 582 that contacts the third contact portion 561, it is possible to more reliably suppress the impact on the positioning accuracy of the tray unit 50.

[0168] In this embodiment, the connecting shaft 582 only needs to be prevented from rotating relative to the left side frame 100L and the right side frame 100R, and the rotation restriction configuration does not have to be one in which the engaging portion is non-circular. Furthermore, the non-circular shape is not limited to D shape, and may, for example, have multiple planar sections (multiple straight sections). <Example 4> The method for positioning the tray unit 50 relative to the apparatus body 1A in Embodiment 4 will be explained using Figures 12 to 15 and Figure 17. In this embodiment, components common to Embodiments 1 to 3 are denoted by the same reference numerals, and components different from Embodiments 1 to 3 will be mainly described. Matters not specifically described here in this embodiment are the same as in Embodiments 1 to 3.

[0169] Figure 17 is a perspective view illustrating the positioning configuration of the tray unit 50 at the rear end in the insertion direction relative to the main body 1A of the apparatus in this embodiment. A tray shaft 592 is provided on the side of the tray unit 50 closest to the tray handle 52, extending outward from the left side frame 100L and the right side frame 100R. As shown in Figure 17, the engagement portion of the tray shaft 592 with the tray unit 50 is non-circular. Specifically, the engagement portion with the tray unit 50 has a so-called D shape, including an arc portion and a flat portion (straight portion). In other words, the tray shaft 592 is configured not to rotate freely relative to the tray unit 50.

[0170] The other configurations in Example 4 are the same as those in Example 2.

[0171] In Example 4, since the tray shaft 592 is not rotatable, the surface that abuts against the third contact portion 562 is always the same.

[0172] As shown in Figures 19(a) and 19(b), 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. If the tray shaft 592 does not rotate, neither the first contact portion 542 nor the second contact portion 552 will contact the third contacted portion 93, and the third contact portion 562 will not contact neither the first contacted portion 91 nor the second contacted portion 92.

[0173] Therefore, even if the tray shaft 592 wears down due to repeated pulling out and attaching of the tray unit 50 or forceful attachment, it does not affect the surface of the tray shaft 592 that contacts the first contact portion 542 and the second contact portion 552. In other words, the areas of the tray shaft 592 that contact the first contact portion 542, the second contact portion 552, and the third contact portion 562 are always different areas because the rotation of the tray shaft 592 is restricted. Therefore, even if wear occurs in the area of ​​the tray shaft 592 that contacts the third contact portion 562, it is possible to more reliably suppress the impact on the positioning accuracy of the tray unit 50.

[0174] In this embodiment, the tray shaft 592 is designed not to rotate relative to the tray unit 50. It is sufficient to do so, and the rotation restriction configuration does not have to be one in which the engaging portion is non-circular. Furthermore, the non-circular shape is not limited to D-shape, and may, for example, have multiple planar sections (multiple straight sections).

[0175] The configurations of each of the above embodiments can be combined with each other.

[0176] The disclosure of embodiments of the present invention includes the following configurations. (Composition 1) An image forming apparatus configured to perform an image forming operation on a recording material, The main body of the device, A pull-out section movable relative to the device body in an insertion direction and a pull-out direction opposite to the insertion direction, wherein the pull-out section is movable relative to the device body to a mounting position, a pull-out position located downstream of the mounting position in the pull-out direction, and a restricted position located downstream of the mounting position in the insertion direction. The device body and the drawer portion are provided with an engaging portion, The engagement portion provided on the other side of the device body and the drawer portion, A positioning portion including a first contact portion and a second contact portion, wherein when the pull-out portion is in the mounting position, the first contact portion, the second contact portion and the engaging portion come into contact, the contact between the first contact portion and the engaging portion restricts the movement of the pull-out portion in the insertion direction, and the contact between the second contact portion and the engaging portion restricts the movement of the pull-out portion in the pull-out direction, When the pull-out portion reaches a restricted position downstream of the mounting position in the insertion direction, a restricting portion comes into contact with the engaging portion and restricts the movement of the pull-out portion in the insertion direction, A return portion that contacts the engaging portion when the pull-out portion is in the restricted position, and moves the pull-out portion from the restricted position to the mounting position by the weight of the pull-out portion, A engaged portion having, An image forming apparatus characterized by comprising: (Configuration 2) The image forming apparatus according to configuration 1, characterized in that the image forming operation can be performed when the drawer portion is in the mounting position. (Composition 3) The engagement portion includes a first contacted portion that contacts the first contacted portion, a second contacted portion that contacts the second contacted portion, and a third contacted portion that contacts the regulating portion. The image forming apparatus according to configuration 2, characterized in that the first contact portion, the second contact portion, and the third contact portion are arranged at different positions from each other. (Composition 4) An image forming apparatus according to any one of configurations 1 to 3, characterized in that the insertion direction is inclined downward from the upstream side to the downstream side. (Composition 5) The image forming apparatus according to any one of configurations 1 to 4, characterized in that the movement of the pull-out portion in an intersecting direction that intersects the insertion direction is restricted by the contact between the first contact portion, the second contact portion, and the engaging portion. (Composition 6) The image forming apparatus according to any one of configurations 1 to 5, characterized in that the rotation of the engaging portion relative to the one is restricted. (Composition 7) An image forming apparatus according to any one of configurations 1 to 6, characterized in that it includes a cartridge that can be detachably attached to the drawer portion. (Composition 8) An image forming apparatus according to any one of configurations 1 to 7, characterized in that when the engaging portion is in contact with the return portion, the return portion extends in a direction intersecting the horizontal direction and the direction of gravity. (Composition 9) The drawer portion has the engaging portion, and the device body has the engaged portion. An image forming apparatus according to any one of the configurations 1 to 8 characterized by the above. (Composition 10) The image forming apparatus according to configuration 9, characterized in that, in the insertion direction, the restricting portion is located downstream of the first contact portion and the second contact portion. (Composition 11) The image forming apparatus according to configuration 9 or 10, characterized in that the first contact portion is a first inclined surface, the second contact portion is a second inclined surface, the direction in which the first inclined surface extends intersects with respect to the horizontal direction and the direction of gravity, and the direction in which the second inclined surface extends intersects with respect to the horizontal direction and the direction of gravity. (Composition 12) The image forming apparatus according to any one of the configurations 9 to 11, characterized in that the pull-out portion has an upstream end and a downstream end in the insertion direction, and the engaging portion is closer to the upstream end than to the downstream end. (Composition 13) The drawer portion has the engaged portion, and the device body has the engaged portion. An image forming apparatus according to any one of the configurations 1 to 8 characterized by the above. (Composition 14) The image forming apparatus according to configuration 13, characterized in that, in the insertion direction, the restricting portion is located upstream of the first contact portion and the second contact portion. (Composition 15) The image forming apparatus according to configuration 13 or 14, characterized in that the first contact portion is a first inclined surface, the second contact portion is a second inclined surface, and when the pull-out portion is in the mounting position, the direction in which the first inclined surface extends intersects with the horizontal direction and the direction of gravity, and the direction in which the second inclined surface extends intersects with the horizontal direction and the direction of gravity. (Composition 16) The image forming apparatus according to any one of the configurations 13 to 15, characterized in that the pull-out portion has an upstream end and a downstream end in the insertion direction, and the engaging portion is closer to the downstream end than to the upstream end. [Explanation of symbols]

[0177] 1...Printer, 1A...Main unit, 40...Transfer unit, 41...Belt, 43...Cleaning unit, 50...Tray unit, PY, PM, PC, PK...Cartridge

Claims

1. An image forming apparatus configured to perform an image forming operation on a recording material, The main body of the device, A pull-out section movable relative to the device body in an insertion direction and a pull-out direction opposite to the insertion direction, wherein the pull-out section is movable relative to the device body to a mounting position, a pull-out position located downstream of the mounting position in the pull-out direction, and a restricted position located downstream of the mounting position in the insertion direction. The device body and the drawer portion are provided with an engaging portion, The engagement portion provided on the other side of the device body and the drawer portion, A positioning portion including a first contact portion and a second contact portion, wherein when the pull-out portion is in the mounting position, the first contact portion, the second contact portion and the engaging portion come into contact, the contact between the first contact portion and the engaging portion restricts the movement of the pull-out portion in the insertion direction, and the contact between the second contact portion and the engaging portion restricts the movement of the pull-out portion in the pull-out direction, When the pull-out portion reaches a restricted position downstream of the mounting position in the insertion direction, a restricting portion comes into contact with the engaging portion and restricts the movement of the pull-out portion in the insertion direction, A return portion that contacts the engaging portion when the pull-out portion is in the restricted position, and moves the pull-out portion from the restricted position to the mounting position by the weight of the pull-out portion, A engaged portion having, An image forming apparatus characterized by comprising:

2. The image forming apparatus according to claim 1, characterized in that the image forming operation can be performed while the drawer portion is in the mounting position.

3. The engagement portion includes a first contacted portion that contacts the first contacted portion, a second contacted portion that contacts the second contacted portion, and a third contacted portion that contacts the regulating portion. The image forming apparatus according to claim 2, characterized in that the first contact portion, the second contact portion, and the third contact portion are arranged at different positions from each other.

4. The image forming apparatus according to any one of claims 1 to 3, characterized in that the insertion direction is inclined downward from the upstream side to the downstream side.

5. The image forming apparatus according to claim 4, characterized in that the movement of the pull-out portion in an intersecting direction that intersects the insertion direction is restricted by the contact between the first contact portion, the second contact portion, and the engaging portion.

6. The image forming apparatus according to claim 1, characterized in that the rotation of the engaging portion relative to one of the other portions is restricted.

7. The image forming apparatus according to claim 1, characterized in that it includes a cartridge that can be detachably attached to the drawer portion.

8. The image forming apparatus according to claim 1, characterized in that, when the engaging portion is in contact with the return portion, the return portion extends in a direction intersecting the horizontal direction and the direction of gravity.

9. The drawer portion has the engaging portion, and the device body has the engaged portion. The image forming apparatus according to feature 1.

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

11. The image forming apparatus according to claim 9 or 10, characterized in that the first contact portion is a first inclined surface, the second contact portion is a second inclined surface, the direction in which the first inclined surface extends intersects with the horizontal direction and the direction of gravity, and the direction in which the second inclined surface extends intersects with the horizontal direction and the direction of gravity.

12. The image forming apparatus according to claim 9 or 10, wherein the extraction portion has an upstream end and a downstream end with respect to the insertion direction, and the engaging portion is closer to the upstream end than to the downstream end.

13. The drawer portion has the engaged portion, and the device body has the engaged portion. The image forming apparatus according to feature 1.

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

15. The image forming apparatus according to claim 13 or 14, characterized in that the first contact portion is a first inclined surface, the second contact portion is a second inclined surface, and when the pull-out portion is in the mounting position, the direction in which the first inclined surface extends intersects with the horizontal direction and the direction of gravity, and the direction in which the second inclined surface extends intersects with the horizontal direction and the direction of gravity.

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

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