Image forming apparatus

Abstract

The present invention provides an image forming apparatus that allows for the positioning of the feeding tray relative to the main body of the apparatus, even when the sheet support portion of the feeding tray moves when a sheet is supplied. [Solution] The image forming apparatus 1 comprises an apparatus body 2 that houses an image forming unit 5 and has a sheet supply port 21a, and a supply tray 7 that is movable between a closed position and an open position to open and close the sheet supply port 21a, and when in the open position, is capable of supplying a sheet S to the image forming unit 5 through the sheet supply port 21a. The supply tray 7 has a paper feed roller 37, an MP tray cover 71 that can open and close the sheet supply port 21a, an MP tray 72 that moves closer to and further away from the paper feed roller 37 and moves in conjunction with the opening and closing operation of the MP tray cover 71, and a guide member 73 that restricts the movement of the MP tray 72 in the width direction and guides the movement of the MP tray 72 relative to the MP tray cover 71. The apparatus body 2 has a positioning recess 251 that positions the guide member 73 in the width direction.

Description

Technical Field

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

Background Art

[0002] Conventionally, as disclosed in Patent Document 1, there is known an image forming apparatus including a device main body and a manual tray which is a feed tray capable of feeding a sheet by hand to the device main body.

[0003] At the tip of the tray main body portion on which the sheet is placed in the manual tray, a protruding rib is formed, and a protrusion with a sharp tip is formed on the device main body side of the rib. In the device main body, a notch portion into which the protrusion of the manual tray is inserted when the manual tray is opened is formed.

[0004] When the manual tray is opened and the protrusion of the manual tray is inserted into the notch portion of the device main body, movement of the manual tray in the width direction orthogonal to the sheet feeding direction with respect to the device main body is suppressed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the feed tray, when the sheet support portion of the feed tray is configured to move up and down with respect to other portions of the feed tray when feeding the sheet to the device main body, it is necessary to provide a clearance around the sheet support portion so as not to interfere with the up and down movement of the sheet support portion. Therefore, it is difficult to provide a positioning portion for the device main body on the sheet support portion of the feed tray as in the image forming apparatus described in Patent Document 1.

[0007] Therefore, the present invention provides an image forming apparatus that can position the feeding tray relative to the main body of the apparatus, even if the sheet support portion of the feeding tray moves when a sheet is supplied. [Means for solving the problem]

[0008] The image forming apparatus that solves the above problems has the following features.

[0009] That is, the image forming apparatus comprises an apparatus body that houses an image forming unit and has a sheet supply port to the image forming unit, and a supply tray that is movable between a closed position that closes the sheet supply port and an open position that opens the sheet supply port, and which is capable of supplying sheets to the image forming unit through the sheet supply port when in the open position, the supply tray having a paper supply roller that feeds sheets in the feeding direction, a tray cover that can open and close the sheet supply port, a sheet support plate that supports the sheets and moves closer to and further away from the paper supply roller, a sheet support plate that moves relative to the tray cover in conjunction with the opening and closing operation of the tray cover, and a guide member that restricts the movement of the sheet support plate in the width direction perpendicular to the feeding direction and guides the movement of the sheet support plate relative to the tray cover, the apparatus body having a first positioning unit that positions the guide member in the width direction.

[0010] This allows the sheet support plate to be positioned relative to the device body in the width direction, even if the sheet support plate is configured to move closer to and further away from the paper feed roller.

[0011] Furthermore, the guide member has a second positioning section for positioning the guide member with respect to the first positioning section, and a third positioning section for positioning the guide member with respect to the tray cover, and the second positioning section and the third positioning section are aligned along the feeding direction.

[0012] This improves the positioning accuracy of the feeding tray with a tray cover relative to the main body of the device.

[0013] Furthermore, the guide member is screwed to the tray cover between the second positioning portion and the third positioning portion.

[0014] This prevents deformation of the guide member even when a force in the width direction is applied to the guide member while the feed tray is in the open position, thereby maintaining the positional accuracy of the feed tray relative to the device body.

[0015] Furthermore, the apparatus body has a main frame that supports the image forming unit, and the main frame has the first positioning unit.

[0016] As a result, the feeding tray is positioned by the main frame that supports the image forming unit, which suppresses misalignment of the image formed on the sheet supplied from the feeding tray.

[0017] Furthermore, the main frame has a drive frame that supports a drive unit that moves the sheet support plate closer to and further away from the paper feed roller, and the drive frame has the first positioning unit.

[0018] As a result, the drive frame supporting the drive unit of the sheet support plate is located near the feed tray, making it easy to position the feed tray.

[0019] Furthermore, the guide member comprises a first guide member having the second positioning portion, and a second guide member arranged in the width direction relative to the first guide member and not having the second positioning portion.

[0020] If the second positioning portion is provided on both the first guide member and the second guide member, the tolerances of the components constituting the device body and the feeding tray may cause interference between the first guide member, the second guide member and the device body, potentially hindering the smooth opening and closing of the feeding tray. Therefore, by providing the second positioning portion only on the first guide member, the smooth opening and closing of the feeding tray can be maintained.

[0021] Further, the sheet support plate protrudes in the width direction and has a guided protrusion guided by the first guide member. The first guide member has a guide portion in which a long hole into which the guided protrusion is movably inserted is formed. The guided protrusion has a guide positioning portion that sandwiches the guide portion of the first guide member in the width direction. The long hole of the guide portion has a first end where the guided protrusion is located when the feed tray is in the closed position and a second end opposite to the first end where the guided protrusion is located when the feed tray is in the open position. The thickness of the guide portion in the width direction increases from the first end side to the second end side of the long hole. The thickness of the portion of the guide portion sandwiched by the guide positioning portion when the guided protrusion is at the second end of the long hole in the width direction is such that the movement of the guided protrusion in the width direction is restricted by the guide portion.

[0022] Thereby, when the feed tray is in the open position, the positioning of the sheet support plate with respect to the apparatus main body can be performed without hindering the smooth movement of the feed tray.

[0023] Further, the guide member has a rotation shaft portion supported by the apparatus main body so that the tray cover can rotate with respect to the apparatus main body, and the guide member is screwed to the tray cover.

[0024] Thereby, when assembling the rotation shaft portion to the apparatus main body, by removing the screw from the guide member, the guide member can be greatly deformed to facilitate the assembly of the guide member to the apparatus main body. On the other hand, after the guide member is assembled to the apparatus main body, by screwing the guide member to the tray cover, deformation of the guide member can be suppressed, and the feed tray can be prevented from falling off the apparatus main body.

[0025] Further, the guide member has a third positioning portion that positions the guide member with respect to the tray cover, and is screwed to the tray cover between the rotation shaft portion and the third positioning portion in the feeding direction.

[0026] Thus, by removing the screw from the guide member, it becomes possible to greatly deform the guide member starting from the third positioning portion. On the other hand, by screwing the guide member to the tray cover, deformation of the guide member can be effectively suppressed.

[0027] Further, the guide member of the feed tray has a protruding portion as a second positioning portion that protrudes toward the apparatus main body when the feed tray is in the open position, and the apparatus main body has a recess as a first positioning portion into which the protruding portion of the guide member fits when the feed tray is in the open position.

[0028] Thus, by fitting the protruding portion as the second positioning portion of the guide member into the recess as the first positioning portion on the apparatus main body side, the guide member can be accurately positioned with respect to the apparatus main body.

[0029] Further, the protruding portion of the guide member has a protruding portion side taper portion whose width dimension decreases as it goes toward the apparatus main body side at the end portion on the apparatus main body side in the feeding direction when the feed tray is in the open position, and the recess of the apparatus main body has a recess side taper portion whose width dimension increases as it goes toward the guide member side at the end portion on the guide member side in the feeding direction.

[0030] Thus, when the feed tray is moved to the open position, the protruding portion of the guide member can smoothly fit into the recess of the apparatus main body due to the protruding portion side taper portion and the recess side taper portion.

Advantages of the Invention

[0031] According to the present invention, even if the sheet support portion of the feeding tray is configured to move, the feeding tray can be positioned relative to the main body of the device. [Brief explanation of the drawing]

[0032] [Figure 1] This is a central cross-sectional view showing an image forming apparatus. [Figure 2] This is a perspective view showing an image forming apparatus. [Figure 3] This is a left front perspective view showing the front of the device body with the MP tray cover open. [Figure 4] This is a right front perspective view showing the front of the device body with the MP tray cover open. [Figure 5] This is a plan view showing the feed tray in an open state. [Figure 6] This is a plan view showing the feed tray in a closed state. [Figure 7] This is a perspective view showing the first guide member. [Figure 8] (a) is a side view showing the first guide member, and (b) is a top view showing the first guide member. [Figure 9] This is a perspective view showing the second guide member. [Figure 10] (a) is a side view showing the second guide member, and (b) is a top view showing the second guide member. [Figure 11] This is a perspective view showing the MP tray cover to which the first guide member and the second guide member are attached. [Figure 12] This is a plan view showing the MP tray. [Figure 13] This is a side cross-sectional view showing the front of the device body with the MP tray cover closed. [Figure 14] This is a side cross-sectional view showing the front of the device body with the MP tray cover open. [Figure 15](a) is a plan view showing the relationship between the guide portion of the first guide member and the guide positioning portion of the MP tray, with the guided projection of the MP tray positioned at the first end of the elongated hole, and (b) is a side view showing the first guide member with the guided projection of the MP tray positioned at the first end of the elongated hole. [Figure 16] (a) is a plan view showing the relationship between the guide portion of the first guide member and the guide positioning portion of the MP tray, with the guided projection of the MP tray positioned at the second end of the elongated hole, and (b) is a side view showing the first guide member with the guided projection of the MP tray positioned at the second end of the elongated hole. [Figure 17] This is a side cross-sectional view showing the feeding tray with the MP tray cover in the open position and the MP tray moved to a close position by the lifting mechanism. [Figure 18] This is a side cross-sectional view showing the feeding tray with the MP tray cover in the open position and the MP tray moved to a separated position by the lifting mechanism. [Figure 19] This is a perspective view showing the drive frame. [Figure 20] (a) is a plan view showing the drive frame, and (b) is a front view showing the drive frame. [Figure 21] This perspective view shows the MP tray cover, which is in the closed position, moving towards the open position, with the positioning protrusion approaching the positioning recess. [Figure 22] This is a perspective view showing the MP tray cover in the open position with the positioning protrusion fitted into the positioning recess. [Figure 23] This is a front perspective view showing how the open feeding tray is supported by the front cover by inserting the rotating shaft of the guide member into the support hole in the front cover. [Figure 24] This is a plan cross-sectional view showing how the closed feeding tray is supported by the front cover by inserting the rotating shaft of the guide member into the support hole in the front cover. [Figure 25]This plan view shows how removing the screw from the connecting hole allows the portion of the guide member attached to the MP tray cover that is on the rotating shaft side of the positioning hole to be deformed in the left-right direction. [Figure 26] (a) is a plan view showing the portion of the first guide member on the rotating shaft side of the positioning hole with the screw inserted into the connecting hole, and (b) is a plan view showing the portion of the first guide member on the rotating shaft side of the positioning hole with the screw removed from the connecting hole. [Figure 27] This is a side view showing the gear case supporting the conductive bearings of the intermediate discharge roller and the discharge roller. [Figure 28] (a) is a perspective view showing the conductive bearing of the intermediate discharge roller, (b) is a side view showing the conductive bearing of the intermediate discharge roller, and (c) is a plan view showing the conductive bearing of the intermediate discharge roller. [Figure 29] This is a plan view showing the contact state of the ground spring with the conductive bearing of the intermediate discharge roller. [Figure 30] This is a side view showing the contact state of the ground spring with the conductive bearing of the discharge roller. [Modes for carrying out the invention]

[0033] Next, embodiments for carrying out the present invention will be described with reference to the attached drawings.

[0034] [Image forming apparatus] The image forming apparatus 1 shown in Figures 1 and 2 is an embodiment of the image forming apparatus according to the present invention, and is a color laser printer that forms a multi-color image on a sheet S using an electrophotographic method.

[0035] In the following explanation, the right side of Figure 1 is defined as the front side of the image forming apparatus 1, the left side of Figure 1 is defined as the rear side of the image forming apparatus 1, the front of the page in Figure 1 is defined as the left side of the image forming apparatus 1, and the back of the page in Figure 1 is defined as the right side of the image forming apparatus 1. Furthermore, the top and bottom sides of Figure 1 are defined as the top and bottom sides of the image forming apparatus 1, respectively.

[0036] As shown in Figures 1 and 2, the image forming apparatus 1 comprises a main body 2, a paper feeding unit 3 having a paper feed tray 10 for supporting a sheet S and a sheet transport unit 30 for transporting the sheet S, and an image forming unit 5 for forming an image on the sheet S transported by the paper feeding unit 3.

[0037] The main body of the device 2 is formed in a roughly rectangular parallelepiped shape and houses the paper feeding section 3 and the image forming section 5. A front opening 2A is located on the front of the main body of the device 2, and the main body of the device 2 has a front cover 21 that can open and close the front opening 2A.

[0038] The paper feeding unit 3 is located at the bottom of the main body 2 of the device and transports the sheet S, which is supported by the paper feeding tray 10, to the image forming unit 5 via the sheet transport unit 30. The paper feeding tray 10 is configured to slide in the front-rear direction and is movable between a storage position where it is housed in the main body 2 of the device and a detached position where it is pulled forward from the storage position.

[0039] The sheet transport unit 30 includes a paper feed roller 32, a separation roller 33, a separation pad 33a, a transport roller pair 34, and a registration roller pair 35. Inside the main body 2 of the device, a transport path P for sheets S is configured, which goes from the paper feed tray 10 through the image forming unit 5 to the paper output tray 22. The sheets S are transported along the transport path P from the paper feed tray 10 to the paper output tray 22.

[0040] The sheets S supported in the paper feed tray 10 are separated one by one by the paper feed roller 32, the separation roller 33, and the separation pad 33a, and then sent to the transport path P. The paper feed roller 32 is a roller that transports the sheets S from the paper feed tray 10 toward the image forming unit 5. The separation roller 33 and the separation pad 33a constitute a separation means that separates the sheets S supported in the paper feed tray 10 one by one.

[0041] The sheet S, which has been sent onto the transport path P, is transported toward the image forming unit 5 by the transport roller pair 34 and the resist roller pair 35. The resist roller pair 35 restricts the movement of the leading edge of the transported sheet S, stopping it temporarily, and then transports the sheet S toward the image forming unit 5 at a predetermined timing.

[0042] As shown in Figures 1 to 4, the front cover 21 has a sheet supply port 21a that can supply the sheet S toward the image forming unit 5. The sheet supply port 21a is located at the front end of the main body 2 of the apparatus. The sheet supply port 21a is a sheet supply port for the image forming unit 5. The front cover 21 supports an MP tray cover 71 that is rotatable about the rotation axis X of the rotation shaft 732.

[0043] The MP tray cover 71 can move between an open position, where the sheet supply port 21a is open, and a closed position, where the sheet supply port 21a is closed, by rotating around the rotation axis X. The MP tray cover 71 is an example of a tray cover that can open and close the sheet supply port. The rotation axis X of the rotation shaft 732 extends in the left-right direction, and the rotation axis X direction of the MP tray cover 71 is in the left-right direction.

[0044] The MP tray cover 71 supports the MP tray 72. The MP tray 72 can support the sheet S when the MP tray cover 71 is in the open position. The MP tray 72 is an example of a sheet support plate that supports a sheet. The sheet S supported by the MP tray 72 is supplied to the image forming unit 5 through the sheet supply port 21a.

[0045] The image forming apparatus 1 includes a supply mechanism 36 that supplies sheets S supported on an MP tray 72 to an image forming unit 5. The supply mechanism 36 includes a paper feed roller 37, a separation roller 38, and a separation pad 39. The sheets S supported on the MP tray 72 are separated one by one by the paper feed roller 37, the separation roller 38, and the separation pad 39 and sent to a transport path P. The sheets S sent to the transport path P are fed toward the image forming unit 5 by a pair of registration rollers 35. The paper feed roller 37 is a roller that feeds the sheets S in the feeding direction.

[0046] In the image forming apparatus 1, the feeding tray 7 is composed of a paper feed roller 37, an MP tray cover 71, an MP tray 72, and a guide member 73 (see Figures 3 and 4), etc.

[0047] The feeding tray 7 is movable between a closed position, where the sheet supply port 21a is closed, and an open position, where the sheet supply port 21a is open. When in the open position, sheets S can be fed to the image forming unit through the sheet supply port 21a. The feeding tray 7 is in the open position when the MP tray cover 71 is in the open position, and the feeding tray 7 is in the closed position when the MP tray cover 71 is in the closed position.

[0048] The image forming unit 5 is located above the paper feeding unit 3 and includes four toner cartridges 50 arranged in a front-to-back direction, and a photosensitive drum 51 corresponding to each toner cartridge 50. Each toner cartridge 50 corresponds to black, yellow, magenta, and cyan. Each toner cartridge 50 is equipped with a developing roller 52.

[0049] The toner cartridge 50 is detachably supported in a drawer 59. The drawer 59 is detachably attached to the device body 2 through a front opening 2A in the device body 2 by opening the front cover 21. The drawer 59 is movable between a first position where it is located inside the device body 2 and a second position where at least a portion of it is located outside the device body 2. The drawer 59 has a handle 591 for the user to grip when moving the drawer 59 between the first and second positions. The handle 591 is located at the front end of the drawer 59.

[0050] The photosensitive drum 51 is formed in a substantially cylindrical shape with its axis running in the left-right direction and is rotatably supported by the drawer 59. The left-right direction is an example of the width direction, which is perpendicular to the sheet feeding direction. The developing roller 52 extends in the left-right direction and is rotatably supported by the toner cartridge 50. In other words, the drawer 59 supports the photosensitive drum 51 and the developing roller 52. Toner is an example of a developer. The developing roller 52 supplies toner to the photosensitive drum 51.

[0051] The apparatus body 2 includes an exposure apparatus 56 for exposing the surface of the photosensitive drum 51. The exposure apparatus 56 includes a laser diode, a polarizer, a lens, and a mirror (not shown). The exposure apparatus 56 is configured to emit a light beam to each photosensitive drum 51 and expose the surface of each photosensitive drum 51.

[0052] Below the transport path P of the photosensitive drum 51, a transfer belt 41 is positioned opposite. The transfer belt 41 is in contact with the photosensitive drum 51. The transfer belt 41 is stretched between a drive roller 42 and a driven roller 43 positioned in front of the drive roller 42. Transfer rollers 44 are positioned opposite each photosensitive drum 51 on either side of the transfer belt 41. In the image forming unit 5, the belt device 40 is composed of the transfer belt 41, drive roller 42, driven roller 43, and transfer rollers 44, etc.

[0053] The image forming unit 5 is equipped with a charger 54 for charging each photosensitive drum 51. The charger 54 is supported by a drawer 59. The photosensitive drums 51, uniformly charged by the charger 54, are selectively exposed by the exposure device 56. This exposure selectively removes charge from the surface of the photosensitive drum 51, forming an electrostatic latent image on the surface of the photosensitive drum 51.

[0054] The toner contained in the toner cartridge 50 is positively charged and carried on the surface of the developing roller 52. A developing bias is applied to the developing roller 52, and when the electrostatic latent image formed on the photosensitive drum 51 faces the developing roller 52, toner is supplied from the developing roller 52 to the electrostatic latent image due to the potential difference between the electrostatic latent image and the developing roller 52. As a result, a toner image is formed on the surface of the photosensitive drum 51.

[0055] When the sheet S, which has been transported toward the image forming unit 5, reaches the transfer belt 41, it is transported by the transfer belt 41 and passes sequentially between the transfer belt 41 and each photosensitive drum 51. Then, when the toner image supported on the surface of the photosensitive drum 51 comes into contact with the sheet S, it is transferred to the sheet S by the transfer bias applied to the transfer roller 44.

[0056] In this embodiment, the transfer belt 41 is configured as a transport belt that transports the sheet S to which the toner image is transferred. However, it is also possible to configure it as an intermediate transfer belt to which the toner image is transferred to the belt itself, and the toner image transferred to the belt is further transferred to the sheet S.

[0057] The sheet S onto which the toner image has been transferred is transported to the fuser unit 60. The fuser unit 60 is equipped with a heating roller 61 and a pressure roller 62 that presses against the heating roller 61. As the sheet S transported to the fuser unit 60 passes between the heating roller 61 and the pressure roller 62, the toner image is heat-fixed. In other words, the fuser unit 60 fixes the toner image onto the sheet S.

[0058] Downstream of the sheet transport direction from the fuser 60 in the transport path P, there is an intermediate discharge roller 63a that transports the sheet S and a driven roller 63b positioned opposite the intermediate discharge roller 63a. Downstream of the sheet transport direction from the intermediate discharge roller 63a and the driven roller 63b in the transport path P, there is a discharge roller 64a that transports the sheet S and a driven roller 64b positioned opposite the discharge roller 64a.

[0059] The sheet S on which the toner image has been heat-fixed is transported downstream from the fuser 60 in the sheet transport direction, and is further transported by the intermediate discharge roller 63a and driven roller 63b, as well as the discharge roller 64a and driven roller 64b, before being discharged into the output tray 22.

[0060] In the image forming apparatus 1, a process unit PU for forming a toner image on a sheet S is configured by a drawer 59, a toner cartridge 50 supported by the drawer 59, a photosensitive drum 51, and a charger 54, etc. In the process unit PU, the drawer 59 may support the photosensitive drum 51 as in this embodiment, or the toner cartridge 50 may support the photosensitive drum 51. The process unit PU may also include a fuser 60. Alternatively, there may be no drawer 59, and the process unit having the toner cartridge 50 and photosensitive drum 51 may be attached and detached.

[0061] [Main frame] As shown in Figure 2, the device body 2 comprises a first main frame 23 and a second main frame 24, which are spaced apart from each other in the left-right direction. The first main frame 23 is located at the left end of the device body 2, and the second main frame 24 is located at the right end of the device body 2. The first main frame 23 extends in the front-rear and up-down directions and is positioned so that its plate surface faces the left-right direction. The second main frame 24 extends in the front-rear and up-down directions and is positioned so that its plate surface faces the left-right direction.

[0062] The process cartridge 50 and fuser 60, which constitute the image forming unit 5, are positioned between the first main frame 23 and the second main frame 24. The first main frame 23 is located to the left of the process cartridge 50 and fuser 60, and the second main frame 24 is located to the right of the process cartridge 50 and fuser 60. The image forming unit 5 is supported by the first main frame 23 and the second main frame 24. The first main frame 23 is an example of a main frame that supports the image forming unit.

[0063] [Feeding tray] As shown in Figures 2 to 6, the feeding tray 7 includes an MP tray cover 71, an MP tray 72, a guide member 73, and a connecting arm 74.

[0064] The MP tray cover 71 is a plate-shaped cover member. The MP tray cover 71 has a first surface 71a that faces forward when in the closed position, and a second surface 71b that faces backward when in the closed position. The second surface 71b is the surface opposite to the first surface 71a. The first surface 71a of the MP tray cover 71 in the closed position constitutes part of the front view of the image forming apparatus 1. The MP tray 72 is supported by the second surface 71b of the MP tray cover 71.

[0065] The MP tray 72 has a support surface 721 that supports the sheet S. The support surface 721 faces upward when the MP tray cover 71 is in the open position. The MP tray 72 is located in front of the supply mechanism 36 when the MP tray cover 71 is in the open position.

[0066] The sheet S supported on the support surface 721 is transported towards the rear and supplied to the supply mechanism 36. In other words, the direction of supply of the sheet S supported on the support surface 721 is towards the rear.

[0067] The MP tray 72 has side guides 722 that protrude upward from the support surface 721 and guide the left and right ends of the sheet S supported on the support surface 721. The side guides 722 are movable along the left-right direction and a pair is provided on the left and right sides.

[0068] The guide member 73 is formed separately from the MP tray cover 71 and is attached to the second surface 71b of the MP tray cover 71. The guide member 73 has a first guide member 73A and a second guide member 73B. The first guide member 73A and the second guide member 73B are spaced apart in the left-right direction. The second guide member 73B is positioned side by side with respect to the first guide member 73A in the width direction.

[0069] The first guide member 73A is located at the left end of the MP tray cover 71. The second guide member 73B is located at the right end of the MP tray cover 71.

[0070] As shown in Figures 7 and 8, the first guide member 73A includes a guide body 731, a rotating shaft 732, a guide portion 733, connecting holes 734A and 734B, positioning holes 735A and 735B, and a positioning projection 736. The positioning projection 736 is an example of a second positioning portion.

[0071] The guide body 731 is formed from an elongated member extending in a first direction. This first direction is perpendicular to the direction in which the rotation axis X extends. When the MP tray cover 71 is in the open position, this first direction coincides with the feeding direction. When the MP tray cover 71 is in the closed position, the guide body 731 extends in the vertical direction.

[0072] The rotating shaft 732 has a rotation axis X and extends in the left-right direction. The rotating shaft 732 is located at the lower end of the guide body 731 when the MP tray cover 71 is in the closed position. The upstream side in the first direction is the side away from the rotating shaft 732 in the first direction, and the downstream side in the first direction is the side approaching the rotating shaft 732 in the first direction.

[0073] The guide portion 733 is formed in the guide body 731 and extends in a first direction. A long hole 733a is formed in the guide portion 733. In the first direction, the long hole 733a is located away from the rotation axis X of the rotation shaft 732. The long hole 733a penetrates in the left-right direction and is a hole with the first direction as its major axis.

[0074] The connecting holes 734A and 734B are formed in the guide body 731 and penetrate in a direction perpendicular to the second surface 71b of the MP tray cover 71 to which the first guide member 73A is attached. In the first direction, the connecting hole 734A is located between the rotating shaft 732 and the elongated hole 733a. In the first direction, the connecting hole 734B is located further from the rotating shaft 732 than the elongated hole 733a.

[0075] The positioning holes 735A and 735B are formed in the guide body 731 and penetrate in a direction perpendicular to the second surface 71b of the MP tray cover 71 to which the first guide member 73A is attached. In the first direction, the positioning holes 735A and 735B are located between the connecting holes 734A and 734B.

[0076] Positioning hole 735A is located between connecting hole 734A and elongated hole 733a in the first direction. Positioning hole 735B is located between positioning hole 735A and connecting hole 734B in the first direction.

[0077] The positioning projection 736 is the part that positions the first guide member 73A relative to the device body 2. The positioning projection 736 is formed on the guide body 731 and extends from the rotating shaft 732 in a direction perpendicular to the rotation axis X. In the first direction, the positioning projection 736 protrudes from the rotating shaft 732 on the side opposite to the elongated hole 733a.

[0078] As shown in Figures 9 and 10, the second guide member 73B differs from the first guide member 73A in that it does not have a positioning projection 736 and is formed symmetrically with respect to the first guide member 73A, which lacks the positioning projection 736. The other configurations of the second guide member 73B are the same as those of the first guide member 73A. Therefore, a detailed explanation of the second guide member 73B will be omitted.

[0079] In the following description, when it is necessary to distinguish between the first guide member 73A and the second guide member 73B, the first guide member 73A or the second guide member 73B will be used as appropriate. When it is not necessary to distinguish between the first guide member 73A and the second guide member 73B, the guide member 73 will simply be used as appropriate.

[0080] As shown in Figure 11, positioning bosses 712A and 712B are formed on the second surface 71b of the MP tray cover 71, into which the positioning holes 735A and 735B of the guide member 73 are fitted.

[0081] The positioning bosses 712A and 712B are formed corresponding to the positions on the second surface 71b where the first guide member 73A and the second guide member 73B are attached. The positioning bosses 712A and 712B corresponding to the first guide member 73A are located at the left end of the second surface 71b, and the positioning bosses 712A and 712B corresponding to the second guide member 73B are located at the right end of the second surface 71b.

[0082] The positioning hole 735A fits into the positioning boss 712A, and the positioning hole 735B fits into the positioning boss 712B, thereby positioning the guide member 73 relative to the MP tray cover 71.

[0083] For example, the positioning boss 712A is formed in a cylindrical shape, and the positioning hole 735A is formed in a circular shape corresponding to the shape of the positioning boss 712A. When the positioning hole 735A fits into the positioning boss 712A, the guide member 73 is positioned in a direction parallel to the second surface 71b. The positioning hole 735A is an example of a third positioning part that positions the guide member relative to the tray cover.

[0084] Furthermore, for example, the positioning boss 712B is formed in a cylindrical shape, and the positioning hole 735B is formed as an elongated hole with the first direction being the major axis direction. When the positioning hole 735B fits into the positioning boss 712B, the rotational movement of the guide member 73 in a direction parallel to the second surface 71b centered on the positioning boss 712A is restricted.

[0085] With the positioning holes 735A and 735B fitted into the positioning bosses 712A and 712B, the guide member 73 is attached to the MP tray cover 71 by screwing the screws 81 inserted into the connecting holes 734A and 734B into the MP tray cover 71. In other words, the guide member 73 is screwed to the MP tray cover 71.

[0086] As shown in Figure 6, the front cover 21 has a support hole 211 that rotatably supports the pivot shaft 732 of the guide member 73. By inserting the pivot shaft 732 into the support hole 211, the MP tray cover 71 to which the guide member 73 is attached can be rotatably supported by the front cover 21. The pivot shaft 732 is supported by the front cover 21 such that the MP tray cover 71 can rotate around the pivot axis X relative to the front cover 21 of the device body 2.

[0087] In this embodiment, the rotating shaft 732 is formed in the shape of a cylindrical boss, and the front cover 21 has a support hole 211 into which the rotating shaft 732 fits. However, it is also possible to form the rotating shaft 732 in the shape of a cylindrical hole and form a cylindrical boss shape in the front cover 21 that fits onto the rotating shaft 732.

[0088] The support holes 211 of the front cover 21 are formed in two locations corresponding to the first guide member 73A and the second guide member 73B. The support hole 211 into which the pivot shaft 732 of the first guide member 73A is inserted is located at the left end of the front cover 21, and the support hole 211 into which the pivot shaft 732 of the second guide member 73B is inserted is located at the right end of the front cover 21.

[0089] As shown in Figures 3 to 5 and Figure 12, the MP tray 72 has guided projections 723 that protrude in the left-right direction. The guided projections 723 consist of a guided projection 723A located at the left end of the MP tray 72 and a guided projection 723B located at the right end of the MP tray 72. The left guided projection 723A protrudes to the left from the left end of the MP tray 72, and the right guided projection 723B protrudes to the right from the right end of the MP tray 72.

[0090] The guided projections 723 of the MP tray 72 are movably fitted into the elongated holes 733a of the guide member 73. The left guided projection 723A is fitted into the elongated hole 733a of the first guide member 73A from the right, and the right guided projection 723B is fitted into the elongated hole 733a of the second guide member 73B from the left.

[0091] The guided projection 723 of the MP tray 72 is slidably fitted into the elongated hole 733a of the guide member 73, thereby supporting the MP tray 72 so that it can move in a first direction by the MP tray cover 71. When the MP tray 72 moves in the first direction relative to the MP tray cover 71, the guided projection 723 is guided by the elongated hole 733a of the guide member 73.

[0092] As shown in Figures 3 to 6, the image forming apparatus 1 includes a connecting arm 74 that connects the front cover 21 of the apparatus body 2 to the MP tray 72. The connecting arm 74 has a first end 74a that is rotatably supported by the front cover 21 and a second end 74b that is connected to a guided projection 723 of the MP tray 72. The front cover 21 has a support portion 212 that supports the first end 74a of the connecting arm 74 (see Figures 3 and 4). The support portion 212 is located above the support hole 211.

[0093] The connecting arm 74 connected to the left-side guided projection 723 is located to the left of the first guide member 73A, which is positioned on the left side. The connecting arm 74 connected to the right-side guided projection 723 is located to the left of the second guide member 73B, which is positioned on the right side.

[0094] As shown in Figure 13, when the MP tray cover 71 is in the closed position, the guided projection 723 of the MP tray 72 is located at the first end 7331 of the elongated hole 733a of the guide member 73, on the side away from the pivot shaft 732. In this case, the MP tray 72 is moved to a position away from the pivot shaft 732 in the first direction.

[0095] As shown in Figure 14, when the MP tray cover 71 is in the open position, the guided projection 723 of the MP tray 72 is located at the second end 7332 of the elongated hole 733a of the guide member 73, on the side closer to the pivot shaft 732. The second end 7332 is the end of the elongated hole 733a opposite to the first end 7331. In this case, the MP tray 72 is moved closer to the pivot shaft 732 in the first direction compared to when the MP tray cover 71 is in the closed position.

[0096] When the MP tray cover 71 rotates from the open position to the closed position, the connecting arm 74 rotates around its first end 74a in accordance with the rotation of the MP tray cover 71, and the guided projection 723 connected to the connecting arm 74 moves from the second end 7332 to the first end 7331 in the elongated hole 733a of the guide member 73.

[0097] On the other hand, when the MP tray cover 71 rotates from the closed position to the open position, the connecting arm 74 rotates around its first end 74a in accordance with the rotation of the MP tray cover 71, and the guided projection 723 connected to the connecting arm 74 moves from the first end 7331 to the second end 7332 in the elongated hole 733a of the guide member 73.

[0098] In this way, as the guided projection 723 moves within the elongated hole 733a in accordance with the rotation of the MP tray cover 71 to the open and closed positions, the MP tray 72 is guided by the elongated hole 733a and moves in a first direction relative to the MP tray cover 71. In other words, the MP tray 72 moves in a first direction relative to the MP tray cover 71 in accordance with the opening and closing operation of the MP tray cover 71. Furthermore, the elongated hole 733a of the guide member 73 guides the movement of the MP tray 72 relative to the MP tray cover 71.

[0099] [Positioning of the MP tray relative to the first guide member] As shown in Figure 12, the guided projection 723A on the left side of the MP tray 72 has a guide positioning portion 724 that sandwiches the guide portion 733 of the first guide member 73A in the width direction. The guide positioning portion 724 is composed of a projection that protrudes radially from the guided projection 723A and a protruding shape at the base of the guided projection 723. The widthwise length of the guide positioning portion 724 is w2.

[0100] As shown in Figures 15 and 16, the thickness of the first end 7331 side of the guide portion 733 of the first guide member 73A is t2, and the thickness of the end on the second end 7332 side is t3.

[0101] The thickness of the guide portion 733 in the width direction of the first guide member 73A increases from the first end 7331 side to the second end 7332 side of the elongated hole 733a, and the thickness t3 at the end on the second end 7332 side is greater than the thickness t2 at the end on the first end 7331 side.

[0102] As shown in Figure 15, the thickness t2 of the guide portion 733 on the first end 7331 side of the first guide member 73A is smaller than the widthwise length w2 of the guide positioning portion 724. Therefore, when the guided projection 723A of the MP tray 72 is located at the first end 7331 of the elongated hole 733a, a gap exists between the guide positioning portion 724 and the guide portion 733 in the widthwise direction.

[0103] As a result, when the feeding tray 7 is in the closed position and the guided projection 723A is located at the first end 7331 of the elongated hole 733a, the MP tray 72 can move in the width direction by the amount of the gap relative to the first guide member 73A.

[0104] On the other hand, as shown in Figure 16, the thickness t3 of the end of the guide portion 733 on the second end 7332 side of the first guide member 73A is approximately the same as the widthwise length w2 of the guide positioning portion 724. Therefore, when the guided projection 723A of the MP tray 72 is located at the second end 7332 of the elongated hole 733a, there is no gap between the guide positioning portion 724 and the guide portion 733 in the widthwise direction.

[0105] Therefore, when the feeding tray 7 is in the open position and the guided projection 723A is located at the second end 7332 of the elongated hole 733a, the MP tray 72 is restricted from moving in the width direction by the first guide member 73A. As a result, the MP tray 72 is positioned in the width direction with respect to the first guide member 73A.

[0106] In other words, when the guided projection 723A is at the second end 7332 of the elongated hole 733a, the widthwise thickness t3 of the portion of the guide section 733 that is sandwiched by the guide positioning section 724 is such that the widthwise movement of the guided projection 723A is restricted by the guide section 733.

[0107] Thus, when the feeding tray 7 is in the open position, the guide portion 733 and the guide positioning portion 724 position the MP tray 72 in the width direction relative to the first guide member 73A. In this case, the thickness of the guide portion 733 in the width direction increases from the first end 7331 side to the second end 7332 side of the elongated hole 733a, so that the smooth movement of the feeding tray 7 from the closed position to the open position is not hindered.

[0108] [MP tray lifting mechanism] As shown in Figures 17 and 18, the image forming apparatus 1 is equipped with a lifting mechanism 8. The lifting mechanism 8 is a mechanism for moving the MP tray 72 between an approach position (shown in Figure 17) where it is close to the paper feed roller 37 in the sheet transport section 36, and a distanced position (shown in Figure 18) where it is further away from the paper feed roller 37 than the approach position, when the MP tray cover 71 is moved to the open position.

[0109] The MP tray 72 moves closer to and further away from the paper feed roller 37 by the drive of the lifting mechanism 8. The MP tray 72 has a passive projection 726 that protrudes downward at its downstream end in the first direction. The passive projections 726 are located at the left and right ends of the MP tray 72.

[0110] The lifting mechanism 8 includes a lifting lever 81 and a drive gear 82. The lifting lever 81 is rotatably supported on the device body 2 around a pivot axis 81a and is configured to engage with a passive projection 726. The drive gear 82 receives a driving force from a drive source provided by the image forming apparatus 1 and drives the lifting lever 81 with the input driving force. The lifting lever 81 and the drive gear 82 are located on the left and right sides of the MP tray 72.

[0111] In the lifting mechanism 8, the lifting lever 81 is driven upward by the drive gear 82 and rotates, engaging with the passive projection 726 from below. The lifting lever 81, engaged with the passive projection 726, pushes the passive projection 726 upward, moving the MP tray 72 to a close position.

[0112] Furthermore, in the lifting mechanism 8, the lifting lever 81 is driven downward by the drive gear 82, thereby releasing the upward pressure on the passive protrusion 726 by the lifting lever 81. With the upward pressure released, the MP tray 72 moves downward by its own weight, moving to the separated position.

[0113] [Drive frame] As shown in Figures 5 and 13, the first main frame 23 located at the left end of the device body 2 has a drive frame 25. The drive frame 25 supports the sheet transport drive gear 26 and the cam gear 27.

[0114] The sheet transport drive gear 26 is a gear that receives driving force from a drive source in the image forming apparatus 1 and uses that input driving force to drive the separation roller 38 and the paper feed roller 37 of the supply mechanism 36. The cam gear 27 is a gear that receives driving force from a drive source in the image forming apparatus 1 and uses that input driving force to drive the drive gear 82 of the lifting mechanism 8.

[0115] Specifically, when the sheet S supported by the MP tray 72 is supplied to the image forming unit 5 by the supply mechanism 36, the sheet transport drive gear 26 drives the separation roller 38 and the paper feed roller 37. In addition, driving force is transmitted from the cam gear 27 to the drive gear 82, causing the MP tray 72 to move to the approach position.

[0116] On the other hand, when the sheet S supported by the MP tray 72 is not supplied to the image forming unit 5 by the supply mechanism 36, the drive of the separation roller 38 and the paper feed roller 37 is stopped. Also, no driving force is transmitted from the cam gear 27 to the drive gear 82, and the MP tray 72 moves to the separated position. The cam gear 27 is an example of a drive unit that moves the sheet support plate closer to and further away from the paper feed roller.

[0117] [Positioning of guide members relative to the device body] As shown in Figures 19 and 20, the drive frame 25 has a positioning recess 251 for positioning the first guide member 73A relative to the device body 2. The positioning recess 251 is an example of a first positioning part. The positioning recess 251 is open toward the front. The positioning projection 736 of the first guide member 73A can be fitted into the positioning recess 251.

[0118] As shown in Figure 20(a), the width of the positioning recess 251 in the left-right direction is w1. As shown in Figure 8(b), the thickness of the positioning projection 736 in the left-right direction is t1. The width of the positioning recess 251 w1 and the thickness of the positioning projection 736 t1 are formed to be approximately the same size, allowing the positioning projection 736 to slidably fit into the positioning recess 251. The fitting of the positioning projection 736 and the positioning recess 251 positions the first guide member 73A in the width direction relative to the drive frame 25.

[0119] As shown in Figure 13, when the feed tray 7 is in the closed position, the positioning recess 251 and the positioning projection 736 are separated in the front-rear direction and do not engage with each other. Therefore, when the feed tray 7 is in the closed position, the positioning recess 251 does not position the first guide member 73A in the width direction relative to the drive frame 25. The positioning projection 736 protrudes downward from the rotating shaft 732 when the feed tray 7 is in the closed position.

[0120] Furthermore, when the feed tray 7 is in the closed position, the positioning projection 736 is located above the lower end of the MP tray cover 71. In other words, the positioning projection 736 does not protrude below the lower end of the MP tray cover 71. Therefore, when the feed tray 7 moves between the closed and open positions, the positioning projection 736 does not interfere with the paper feed tray 10 located below the MP tray cover 71, and does not hinder the smooth opening and closing operation of the feed tray 7. The positioning projection 736 of the drive frame 25 is also located above the lower end of the MP tray cover 71.

[0121] As shown in Figure 21, when the MP tray cover 71, which is in the closed position, moves towards the open position around the pivot shaft 732, the positioning projection 736 moves backward and approaches the positioning recess 251.

[0122] As shown in Figure 22, when the MP tray cover 71 moves further to the open position, the positioning projection 736 fits into the positioning recess 251 from the front, and the widthwise position of the first guide member 73A is positioned relative to the drive frame 25. The positioning recess 251 is an example of a recess that serves as a first positioning part into which the projection of the guide member fits when the feed tray is in the open position.

[0123] Furthermore, when the feeding tray 7 is in the open position, the positioning projection 736 protrudes rearward from the rotating shaft 732. In other words, when the feeding tray 7 is in the open position, the positioning projection 736 protrudes toward the main body of the device 2. The positioning projection 736 is an example of a projection that acts as a second positioning part, protruding toward the main body of the device when the feeding tray is in the open position.

[0124] Furthermore, the positioning projection 736 of the drive frame 25 is located below the rotation axis X of the rotation shaft 732. Therefore, it is possible to extend the positioning projection 736 forward to a position where it overlaps with the rotation shaft 732 when viewed from above. This increases the engagement length in the front-rear direction between the positioning projection 736 and the positioning recess 251 when the positioning projection 736 is fitted into the positioning recess 251, thereby improving the positioning accuracy of the first guide member 73A relative to the drive frame 25.

[0125] As shown in Figures 19 and 20, the positioning recess 251 of the drive frame 25 has a recess-side tapered portion 251a at the front end, which is the end on the first guide member 73A side in the feeding direction, and the size in the width direction increases as it moves forward toward the first guide member 73A side.

[0126] Furthermore, as shown in Figures 7 and 8, the positioning projection 736 of the first guide member 73A has a tapered projection 736a at its rear end, which is the end on the device body 2 side in the feeding direction when the feeding tray 7 is in the open position, and the width of the projection decreases as it moves towards the rear on the device body 2 side.

[0127] Therefore, when the positioning projection 736 is fitted into the positioning recess 251, even if there is a slight misalignment in the width direction between the positioning projection 736 and the positioning recess 251, the positioning projection 736 is guided by the recess-side tapered portion 251a and the projection-side tapered portion 736a to a position corresponding to the width direction of the positioning recess 251. This allows the positioning projection 736 to fit smoothly into the positioning recess 251.

[0128] Thus, in the image forming apparatus 1, when the feed tray 7 moves to the open position, the positioning projection 736 and the positioning recess 251 engage, thereby positioning the widthwise position of the first guide member 73A relative to the drive frame 25. In this case, since the drive frame 25 is provided on the first main frame 23 of the apparatus body 2, the widthwise position of the first guide member 73A relative to the apparatus body 2 can be positioned.

[0129] Furthermore, when the feeding tray 7 is in the open position, the guide portion 733 and the guide positioning portion 724 position the MP tray 72 in the width direction relative to the first guide member 73A. Thus, the positioning projection 736 and the positioning recess 251 can position the MP tray 72 in the width direction relative to the device body 2.

[0130] Furthermore, the drive frame 25, in which the positioning recess 251 is formed, is provided on the first main frame 23 that supports the image forming unit 5. In addition, the widthwise positioning of the MP tray 72, which supports the sheet S fed toward the image forming unit 5, is performed by the first main frame 23 that supports the image forming unit 5. This makes it possible to suppress misalignment of the image formed on the sheet S supplied from the MP tray 72.

[0131] Furthermore, the drive frame 25, which supports the cam gear 27 that drives the MP tray 72, is located close to the MP tray 72. Therefore, the drive frame 25 has a positioning recess 251, which makes it easy to position the MP tray 72.

[0132] Furthermore, the positioning recess 251 is formed not on the MP tray 72, but on the drive frame 25 provided on the first main frame 23 of the device body 2. Therefore, even if the MP tray 72 is configured to move closer to and further away from the paper feed roller 37, it is possible to position the widthwise position of the MP tray 72 relative to the device body 2.

[0133] Furthermore, the widthwise positioning of the first guide member 73A with respect to the device body 2 is achieved by the positioning projection 736 of the first guide member 73A fitting into the positioning recess 251 on the device body 2 side. Therefore, it is possible to position the first guide member 73A with high precision relative to the device body 2.

[0134] Furthermore, in the image forming apparatus 1, the positioning projection 736 is provided only on the first guide member 73A and not on the second guide member 73B.

[0135] If positioning protrusions 736 are provided on both the first guide member 73A and the second guide member 73B, the tolerances of the components constituting the device body 2 and the feeding tray 7 may cause interference between the first guide member 73A and the second guide member 73B, on which the positioning protrusions 736 are provided, and the device body 2, on which the positioning recess 251 is provided, potentially hindering the smooth opening and closing of the feeding tray 7.

[0136] Therefore, by providing the positioning projection 736 only on the first guide member 73A, it is possible to maintain the smooth opening and closing of the feeding tray 7.

[0137] [Assembly of the feed tray to the front cover] As shown in Figures 23 and 24, the feeding tray 7 is rotatably supported relative to the front cover 21 by inserting the rotating shaft 732 of the guide member 73 into the support hole 211 of the front cover 21.

[0138] The front cover 21 has a pair of left and right support holes 211. The pivot shaft 732 of the first guide member 73A is inserted into the left support hole 211 from the right, and the pivot shaft 732 of the second guide member 73B is inserted into the right support hole 211 from the left. In other words, the pivot shafts 732 of the first guide member 73A and the second guide member 73B are inserted into the support holes 211 of the front cover 21, respectively, from the inside outwards in the left-right direction.

[0139] The guide member 73 is screwed to the MP tray cover 71 by screwing screws 81, which are inserted into connecting holes 734A and 734B, into the MP tray cover 71. By removing the screws 81 inserted into the connecting hole 734A of the guide member 73, it becomes possible to easily assemble the guide member 73 to the front cover 21.

[0140] In other words, by removing the screw 81 from the connecting hole 734A, it becomes possible to deform the portion of the guide member 73 on the rotating shaft 732 side of the positioning hole 735A in the left-right direction, as shown in Figures 24 and 25.

[0141] Therefore, by deforming the portion of the first guide member 73A on the rotating shaft 732 side to the right, and deforming the portion of the second guide member 73B on the rotating shaft 732 side to the left, the left and right rotating shafts 732 can be easily inserted into the support holes 211.

[0142] The deformation of the first guide member 73A and the second guide member 73B can be performed, for example, such that the distance L2 between the left and right rotating shafts 732 becomes smaller than the distance L1 between the left and right support holes 211.

[0143] Furthermore, when inserting the left and right rotating shafts 732 into the support holes 211 one at a time, the assembly can be made easier by deforming the guide member 73 so that, with one rotating shaft 732 inserted into the support hole 211, the other rotating shaft 732 is positioned on the left and right inner sides of the support hole 211.

[0144] As shown in Figure 26(a), the first guide member 73A, which is screwed to the MP tray cover 71, is positioned relative to the MP tray cover 71 at the positioning hole 735A, which fits into the positioning boss 712A. It is also fixed to the MP tray cover 71 at the connecting hole 734A into which the screw 81 is inserted.

[0145] The connecting hole 734A is located between the rotating shaft 732 and the positioning hole 735A in the first direction, which is the feeding direction. Therefore, the first guide member 73A, which is screwed in at the portion of the connecting hole 734A, is deformable in the portion closer to the rotating shaft 732 than the connecting hole 734A.

[0146] On the other hand, as shown in Figure 26(b), when the screw 81 is removed from the connecting hole 734A, the fixing of the first guide member 73A to the MP tray cover 71 at the portion of the connecting hole 734A is released. Therefore, the portion of the first guide member 73A closer to the rotating shaft 732 than the portion of the positioning hole 735A becomes deformable.

[0147] In this case, the distance L4 from the positioning hole 735A to the rotating shaft 732 in the first guide member 73A is greater than the distance L3 from the connecting hole 734A to the rotating shaft 732. Therefore, the amount of lateral deformation of the portion of the first guide member 73A on the rotating shaft 732 side can be increased when the deformation is centered on the positioning hole 735A compared to when the deformation is centered on the connecting hole 734A. The same applies to the second guide member 73B.

[0148] This allows the screw 81 to be removed from the connecting hole 734A, thereby significantly deforming the portion of the guide member 73 that is closer to the rotating shaft 732 than the positioning hole 735A, making it easier to assemble the guide member 73 to the front cover 21.

[0149] Furthermore, after assembling the guide member 73 to the front cover 21, inserting the screw 81 into the connecting hole 734A and fastening it to the MP tray cover 71 can suppress deformation of the part of the guide member 73 on the side of the rotating shaft 732. This prevents the rotating shaft 732 of the guide member 73 from unexpectedly coming out of the support hole 211 of the front cover 21 and the feeding tray 7 from falling off the front cover 21.

[0150] [Positional relationship between the positioning projection and the positioning hole in the first guide member] As shown in Figure 26, the first guide member 73A has a positioning projection 736 for positioning the first guide member 73A relative to the device body 2, and a positioning hole 735A for positioning the first guide member 73A relative to the MP tray cover 71.

[0151] The positioning projection 736 and the positioning hole 735A are arranged side by side along the first direction, which is the feeding direction. The positioning projection 736 is located downstream of the positioning hole 735A in the first direction.

[0152] In this way, the positioning projection 736 and the positioning hole 735A are aligned along the first direction, which makes it possible to improve the positioning accuracy of the feeding tray 7 having the MP tray cover 71 relative to the device body 2.

[0153] Furthermore, in the first guide member 73A, a connecting hole 734A is located between the positioning projection 736 and the positioning hole 735A, and the first guide member 73A is screwed to the MP tray cover 71 between the positioning projection 736 and the positioning hole 735A.

[0154] In other words, the first guide member 73A is fixed to the MP tray cover 71 at the portion of the connecting hole 734A, which is located closer to the positioning projection 736 than the portion of the positioning hole 735A that is positioned in the MP tray cover 71.

[0155] Therefore, even when a force in the width direction is applied to the first guide member 73A while the feeding tray 7 is in the open position and the positioning projection 736 is positioning the first guide member 73A relative to the device body 2, deformation of the first guide member 73A can be suppressed. This makes it possible to maintain the positioning accuracy of the feeding tray 7 relative to the device body 2.

[0156] In this embodiment, the lifting mechanism 8 for moving the MP tray 72 between an approaching position and a separated position has a configuration comprising a lifting lever 81 that rotates in the vertical direction and a drive gear 82 that drives the lifting lever 81, but is not limited to this and may have other configurations.

[0157] Furthermore, in this embodiment, the first guide member 73A and the second guide member 73B are separate from the MP tray cover 71 and are screwed in place, but the embodiment is not limited to this, and the first guide member 73A and the second guide member 73B may be integrated with the MP tray cover 71.

[0158] [Grounding of the conductive bearings of the intermediate discharge roller and discharge roller] As shown in Figures 1 and 27, the image forming apparatus 1 is equipped with a gear case 90 to the left of the intermediate discharge roller 63a and the discharge roller 64a. The gear case 90 supports conductive bearings 91 and 92. Conductive bearing 91 is located at the rear and lower end of the gear case 90, and conductive bearing 92 is located in the front-to-rear center of the upper end of the gear case 90.

[0159] The conductive bearing 91 is the bearing for the roller shaft 631 of the intermediate discharge roller 63a, and the roller shaft 631 of the intermediate discharge roller 63a is supported by the gear case 90 via the conductive bearing 91. The conductive bearing 92 is the bearing for the roller shaft 641 of the discharge roller 64a, and the roller shaft 641 of the discharge roller 64a is supported by the gear case 90 via the conductive bearing 92.

[0160] The roller shaft 631 and conductive bearing 91 of the intermediate discharge roller 63a, and the roller shaft 641 and conductive bearing 92 of the discharge roller 64a, are each formed of conductive material.

[0161] The image forming apparatus 1 is supported by a gear case 90 and includes an earth spring 93 that contacts conductive bearings 91 and 92. The earth spring 93 is conductive and grounded. By the earth spring 93 contacting conductive bearings 91 and 92, conductive bearings 91 and roller shaft 631, as well as conductive bearings 92 and roller shaft 641, are grounded.

[0162] The ground spring 93 extends upward from the rear and lower end of the gear case 90, then bends at the upper end of the gear case 90 and extends forward. By contacting the conductive bearings 91 and 92, the ground spring 93 can ground two locations of the conductive bearings 91 and 92 with a single ground spring 93.

[0163] As shown in Figure 28, the conductive bearing 91 has a bearing body 911, a leg portion 912, a contact portion 913, and a regulating portion 914. The bearing body 911 is formed in a cylindrical shape through which the roller shaft 631 is inserted. The axial direction of the bearing body 911 is along the left-right direction.

[0164] The leg portion 912 protrudes rearward from the right end of the bearing body 911. The leg portion 912, together with the right end surface of the bearing body 911, contacts the left side surface of the gear case 90, thereby stabilizing the orientation of the conductive bearing 91 relative to the gear case 90. The contact portion 913 protrudes rearward from the bearing body 911 to the left of the leg portion 912. The ground spring 93 makes contact with the contact portion 913.

[0165] The restricting portion 914 protrudes rearward from the bearing body 911 to the left of the contact portion 913. The amount of rearward protrusion of the restricting portion 914 is greater than the amount of rearward protrusion of the contact portion 913, and it is possible to restrict the movement of the ground spring 93, which is in contact with the contact portion 913, to the left.

[0166] As shown in Figure 27, the ground spring 93 passes vertically behind the bearing body 911 in the conductive bearing 91. In the left-right direction, the ground spring 93 is located between the leg portion 912 and the regulating portion 914.

[0167] The image forming apparatus 1 is supported by a gear case 90 and includes a pressure spring 94 that presses the ground spring 93 forward. The ground spring 93 is pressed forward by the pressure spring 94 and comes into contact with the contact portion 913 of the conductive bearing 91.

[0168] The gear case 90 has a first pressing piece 901 and a second pressing piece 902 that press the ground spring 93 to the right. The first pressing piece 901 presses the ground spring 93 to the right below the conductive bearing 91, and the second pressing piece 902 presses the ground spring 93 to the right above the conductive bearing 91.

[0169] The earth spring 93 is pressed to the right by the first pressing piece 901 and the second pressing piece 902, thereby contacting the leg portion 912 of the conductive bearing 91.

[0170] As shown in Figure 29, the ground spring 93 is in contact with the conductive bearing 91 at two points, the contact portion 913 and the leg portion 912, making it possible to stably maintain contact between the ground spring 93 and the conductive bearing 91.

[0171] Furthermore, the earth spring 93 presses the leg portion 912 toward the right, restricting the conductive bearing 91 from moving toward the left. As a result, the leftward movement of the conductive bearing 91 is suppressed, so even if the length of the roller shaft 631 protruding to the left from the conductive bearing 91 is shortened, the conductive bearing 91 will not come out of the roller shaft 631.

[0172] As shown in Figure 30, the conductive bearing 92 is configured similarly to the conductive bearing 91, and has a bearing body 921, legs 922, contact portion 923, and restricting portion 924. The bearing body 921, legs 922, contact portion 923, and restricting portion 924 correspond to the bearing body 911, legs 912, contact portion 913, and restricting portion 914, respectively. However, the legs 922, contact portion 923, and restricting portion 924 of the conductive bearing 92 protrude downward from the bearing body 921.

[0173] The ground spring 93 passes below the bearing body 921 in the conductive bearing 92 along the front-rear direction. In the left-right direction, the ground spring 93 is located between the leg portion 922 and the regulating portion 924.

[0174] The gear case 90 has a third pressing piece 903 and a fourth pressing piece 904 that press the ground spring 93 upward. The ground spring 93 is pressed upward by the third pressing piece 903 and the fourth pressing piece 904 and contacts the contact portion 923 of the conductive bearing 92.

[0175] The gear case 90 has a fifth pressing piece 905 and a sixth pressing piece 906 that press the ground spring 93 to the right. The fifth pressing piece 905 presses the ground spring 93 to the right behind the conductive bearing 92, and the sixth pressing piece 906 presses the ground spring 93 to the right in front of the conductive bearing 92.

[0176] The earth spring 93 is pressed to the right by the fifth pressing piece 905 and the sixth pressing piece 906, thereby contacting the leg portion 922 of the conductive bearing 92.

[0177] Thus, since the ground spring 93 is in contact with the conductive bearing 92 at two points, the contact portion 923 and the leg portion 922, it is possible to make stable contact between the ground spring 93 and the conductive bearing 92.

[0178] Furthermore, the earth spring 93 presses the leg portion 922 to the right, restricting the leftward movement of the conductive bearing 92. As a result, the leftward movement of the conductive bearing 92 is suppressed, so even if the length of the leftward protrusion of the roller shaft 641 from the conductive bearing 92 is shortened, the conductive bearing 92 will not come out of the roller shaft 641. [Explanation of Symbols]

[0179] 1. Image forming apparatus 2. Main unit of the device 5 Image forming unit 7 Feeding tray 21 Front cover 21a Sheet supply port 23. First main frame 25 Drive frame 37 Paper feed roller 51 Photosensitive drum 52 Developing roller 59 drawers 71 MP Tray Cover 71A Tray support section 71B Bending section 72 MP Tray 73 Guide member 73A First guide member 73B Second guide member 81 screws 251 Positioning recess 251a Recessed side tapered portion 712A Positioning Boss 721 Linking Boss 722 Support surface 723, 723A, 723B Guided projection 724 Guide positioning section 732 Rotating shaft 733 Information Department 733a long hole 734A connection hole 735A Positioning hole 736 Positioning protrusion 736a Tapered section on the protruding part side 7331 First end 7332 Second end S Seat t2 (thickness of the first end of the guide portion in the first guide member) t3 (thickness of the second end of the guide portion in the first guide member) w2 (length in the width direction of the guide positioning section)

Claims

1. The apparatus body includes an image forming unit and a sheet supply port for the image forming unit, The system includes a feeding tray that is movable between a closed position that closes the sheet feeding port and an open position that opens the sheet feeding port, and which is capable of feeding sheets to the image forming unit through the sheet feeding port when in the open position, The aforementioned feeding tray is A paper feed roller that feeds the sheet in the feeding direction, A tray cover that can open and close the sheet supply opening, A sheet support plate that supports a sheet and moves closer to and further away from the paper feed roller, the sheet support plate moving relative to the tray cover in conjunction with the opening and closing operation of the tray cover, The device includes a guide member that restricts the movement of the sheet support plate in the width direction perpendicular to the feeding direction and guides the movement of the sheet support plate relative to the tray cover, The image forming apparatus is characterized in that the apparatus body has a first positioning unit for positioning the guide member in the width direction.

2. The guide member has a second positioning unit for positioning the guide member with respect to the first positioning unit, and a third positioning unit for positioning the guide member with respect to the tray cover. The image forming apparatus according to claim 1, wherein the second positioning section and the third positioning section are arranged along the feeding direction.

3. The image forming apparatus according to claim 2, wherein the guide member is screwed to the tray cover between the second positioning portion and the third positioning portion.

4. The apparatus body has a main frame that supports the image forming unit, The image forming apparatus according to any one of claims 1 to 3, wherein the main frame has the first positioning portion.

5. The main frame has a drive frame that supports a drive unit that moves the sheet support plate closer to and further away from the paper feed roller. The image forming apparatus according to claim 4, wherein the drive frame has the first positioning portion.

6. The image forming apparatus according to claim 2, wherein the guide member comprises a first guide member having the second positioning portion and a second guide member arranged in the width direction relative to the first guide member and not having the second positioning portion.

7. The sheet support plate has a guided projection that protrudes in the width direction and is guided by the first guide member, The first guide member has a guide portion in which an elongated hole is formed into which the guided projection is movably inserted, The guided projection has a guide positioning portion that sandwiches the guide portion of the first guide member in the width direction, The elongated hole in the guide portion has a first end where the guided projection is located when the feeding tray is in the closed position, and a second end opposite to the first end where the guided projection is located when the feeding tray is in the open position. The thickness of the guide portion in the width direction increases from the first end side to the second end side of the elongated hole. The image forming apparatus according to claim 6, wherein the thickness in the width direction of the portion of the guide that is sandwiched by the guide positioning portion when the guided projection is at the second end of the elongated hole is such that the movement of the guided projection in the width direction is restricted by the guide.

8. The guide member has a pivot shaft portion supported by the device body so that the tray cover can rotate relative to the device body, The image forming apparatus according to claim 1, wherein the guide member is screwed to the tray cover.

9. The image forming apparatus according to claim 8, wherein the guide member has a third positioning portion for positioning the guide member with respect to the tray cover, and is screwed to the tray cover between the pivot shaft portion and the third positioning portion in the feeding direction.

10. The guide member of the feeding tray has a projection that acts as a second positioning portion and protrudes toward the main body of the device when the feeding tray is in the open position. The image forming apparatus according to claim 1, wherein the apparatus body has a recess serving as a first positioning portion into which the protruding portion of the guide member fits when the feeding tray is in the open position.

11. The protruding portion of the guide member has a tapered portion on the end facing the device body in the feeding direction when the feeding tray is in the open position, the size in the width direction decreasing as it moves toward the device body. The image forming apparatus according to claim 10, wherein the recess of the apparatus body has a recess-side tapered portion at the end on the guide member side in the feeding direction, the size of which in the width direction increases as it approaches the guide member side.

Images