Sheet transport device, image forming apparatus

Abstract

To obtain a sheet conveyance device and an image forming apparatus capable of reducing the resistance to which a conveyed sheet member is subjected compared to a case where the conveyed sheet member passes only in the area sandwiched between a first line and a second line.SOLUTION: The sheet conveyance device includes a first conveyance roll for conveying a sheet member in a first direction, a second conveyance roll whose axial direction is the same as that of the first conveyance roll, arranged on the downstream side of the first conveyance roll in the conveyance direction of the sheet member, and for conveying the sheet member in a second direction that is different from the first direction, and a guiding portion for guiding the sheet member by being in contact with a tip of the sheet member on the side of the second conveyance roll relative to a first line extending in the first direction from the portion where the sheet member is sandwiched in the first conveyance roll, and in an area on the opposite side of the first conveyance roll relative to a second line extending in a second direction from the portion where the sheet member is sandwiched in the second conveyance roll.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a sheet conveying apparatus and an image forming apparatus. [Background Art]

[0002] The sheet conveying apparatus described in Patent Document 1 includes: a conveying unit that conveys a sheet toward a predetermined position; a motor that drives the conveying unit; a sheet detection unit that detects the sheet on a conveying path of the sheet heading toward the predetermined position via the conveying unit; a torque detection unit that detects load torque applied to the motor; and a control unit that executes speed control for changing a rotational speed of the motor in accordance with timing at which the sheet detection unit detects the sheet during execution of a conveying operation of causing the conveying unit to convey the sheet. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2020-190657 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] A sheet conveying apparatus that conveys a sheet member includes a plurality of conveying rolls arranged at intervals from an upstream side to a downstream side in a conveying direction of the sheet member.

[0005] For reasons of machine layout, the conveying direction of the sheet member may differ between a first conveying roll and a second conveying roll arranged on the downstream side of the first conveying roll in the conveying direction of the sheet member. Specifically, the first conveying roll conveys the sheet member in a first direction, and the second conveying roll may convey the sheet member in a second direction different from the first direction. In such a case, a guide portion is provided that guides the sheet member conveyed by the first conveying roll toward the second conveying roll.

[0006] The guide section guides the sheet material within the region enclosed by a first line extending in a first direction from the point where the sheet material is gripped in the first conveyor roll, and a second line extending in a second direction from the point where the sheet material is gripped in the second conveyor roll. In this case, the conveyed sheet material experiences resistance from the guide section. This resistance can sometimes become significant.

[0007] The object of the present invention is to reduce the resistance that the conveyed sheet member receives from the guide section compared to the case where the conveyed sheet member passes only within the area sandwiched between the first and second lines. [Means for solving the problem]

[0008] A sheet conveying device according to a first aspect of the present disclosure is characterized by comprising: a first conveying roll for conveying a sheet member in a first direction; a second conveying roll arranged downstream of the first conveying roll in the conveying direction of the sheet member and conveying the sheet member in a second direction different from the first direction; and a guide portion that contacts the leading edge of the sheet member and guides the sheet member in a region on the second conveying roll side with respect to a first line extending in the first direction from the portion of the first conveying roll where the sheet member is gripped, and on the opposite side from the first conveying roll side with respect to a second line extending in the second direction from the portion of the second conveying roll where the sheet member is gripped.

[0009] A sheet conveying device according to a second aspect of the present disclosure is a sheet conveying device according to the first aspect, characterized in that the guide portion guides the sheet member such that, when viewed from the axial direction of the first conveying roll, the leading edge of the sheet member traces a curved trajectory in which the side away from the second line in the horizontal direction is convex.

[0010] A sheet conveying device according to a third aspect of this disclosure is a sheet conveying device according to the second aspect, wherein the second direction is the vertical direction of the device. Viewed from the axial direction, the guide portion is characterized in that it guides the sheet member such that the leading edge of the sheet member traces a curved trajectory within the region where the second conveyor roll is located in the width direction of the device.

[0011] A sheet conveying device according to a fourth aspect of this disclosure is characterized in that, in the sheet conveying device described in the first aspect, the portion of the guide that contacts the leading edge of the sheet member is curved so that the side that is horizontally away from the second line when viewed from the axial direction of the first conveying roll is convex.

[0012] A sheet conveying device according to a fifth aspect of the present disclosure is a sheet conveying device according to a fourth aspect, characterized in that the second direction is the vertical direction of the device, and the guide portion is arranged in a region in which the second conveying roll is arranged in a direction perpendicular to the axial direction and parallel to the horizontal plane when viewed from the axial direction.

[0013] A sheet conveying device according to a sixth aspect of the present disclosure is a sheet conveying device according to a third or fifth aspect, wherein the second conveying roll has one roll portion arranged on the side of the first conveying roll and another roll portion that sandwiches a sheet member between itself and the first roll portion, and is arranged above the first conveying roll and below the second conveying roll in the vertical direction of the device, and is arranged on the side of the first conveying roll relative to the second conveying roll in the width direction of the device, and is characterized by comprising another guide portion that guides the sheet member so that the leading edge of the sheet member conveyed by the third conveying roll contacts the roll surface of the other roll portion.

[0014] The image forming apparatus according to the seventh aspect of this disclosure is: Any one of the 1st to 6th forms The present invention is characterized by comprising a sheet conveying device as described above, and an image forming unit that forms an image on a sheet member conveyed by the sheet conveying device. [Effects of the Invention]

[0015] The sheet conveying device according to the first aspect of this disclosure can reduce the resistance that the conveyed sheet member receives from the guide compared to the case where the conveyed sheet member passes only within the area sandwiched between the first and second lines.

[0016] The sheet conveying apparatus according to the second aspect of the present disclosure can suppress an abrupt change in resistance that the sheet member receives from the guide portion, as compared with a case where the trajectory of the leading end of the sheet member is bent.

[0017] The sheet conveying apparatus according to the third aspect of the present disclosure can narrow the installation range where the second conveying roll and the guide portion are arranged in the width direction of the apparatus, as compared with a case where the trajectory of the leading end of the sheet member is drawn outside the region where the second conveying roll is arranged in the width direction of the apparatus.

[0018] The sheet conveying apparatus according to the fourth aspect of the present disclosure can suppress an abrupt change in resistance that the sheet member receives from the guide portion, as compared with a case where a bent portion is formed at a portion of the guide portion that the leading end of the sheet member contacts.

[0019] The sheet conveying apparatus according to the fifth aspect of the present disclosure can narrow the installation range where the second conveying roll and the guide portion are arranged in the width direction of the apparatus, as compared with a case where the guide portion is arranged outside the region where the second conveying roll is arranged in the width direction of the apparatus.

[0020] The sheet conveying apparatus according to the sixth aspect of the present disclosure can reduce the resistance that the sheet member receives from the other guide portion before the leading end of the conveyed sheet member comes into contact with the roll surface of the other roll portion, as compared with a case where the leading end of the sheet member conveyed by the third conveying roll directly contacts the nipping portion between one roll portion and the other roll portion.

[0021] The image forming apparatus according to the seventh aspect of the present disclosure can suppress jamming of the sheet member inside the apparatus main body, as compared with a case where the sheet conveying apparatus in which the conveyed sheet member passes only within the region sandwiched between the first line and the second line is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] [Figure 1] FIG. 1 is a schematic configuration diagram illustrating the image forming apparatus according to the embodiment of the present disclosure. [Figure 2]It is a configuration diagram illustrating an image forming unit of an image forming apparatus according to an embodiment of the present disclosure. [Figure 3] It is a configuration diagram illustrating a conveying unit according to an embodiment of the present disclosure. [Figure 4] It is an enlarged configuration diagram illustrating a conveying unit according to an embodiment of the present disclosure. [Figure 5] (A)(B)(C)(D)(E)(F) It is a side view illustrating a sheet member conveyed by a conveying unit according to an embodiment of the present disclosure. [Figure 6] (A)(B)(C) It is a side view illustrating a sheet member conveyed by a conveying unit according to an embodiment of the present disclosure. [Figure 7] It is a drawing showing a graph comparing a conveying unit according to an embodiment of the present disclosure and a conveying unit according to a comparative example with respect to the embodiment. [Figure 8] It is a configuration diagram illustrating a conveying unit according to a comparative example with respect to an embodiment of the present disclosure. [Figure 9] (A)(B)(C)(D)(E)(F) It is a side view illustrating a sheet member conveyed by a conveying unit according to a comparative example with respect to a conveying unit according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF EMBODIMENTS

[0023] An example of a sheet conveying apparatus and an image forming apparatus according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 9. Note that, in each drawing, arrow H indicates the vertical direction, which is the vertical direction of the apparatus; arrow W indicates the horizontal direction, which is the width direction of the apparatus; and arrow D indicates the horizontal direction, which is the depth direction of the apparatus.

[0024] (Overall Configuration of Image Forming Apparatus) As shown in FIG. 1, the image forming apparatus 10 includes: an image forming unit 12 that forms a toner image by an electrophotographic method; a conveying unit 14 that conveys a sheet member P along a conveying path 16; and storage units 60 and 70 that store the sheet member P.

[0025] In the image forming apparatus 10 with the above configuration, sheet members P are housed in the housing sections 60 and 70, and the sheet members P housed in either of the housing sections 60 or 70 are transported along the transport path 16 by the transport section 14. Furthermore, a toner image formed by the image forming section 12 is formed on the transported sheet members P, and the sheet members P on which the toner image has been formed are discharged to the outside of the apparatus body 10a.

[0026] [Image forming unit 12] As shown in Figure 1, the image forming unit 12 includes a plurality of toner image forming units 30, each forming a toner image of a different color, and a transfer unit 32 that transfers the toner images formed by the toner image forming units 30 to a sheet member P. Furthermore, the image forming unit 12 includes a fixing device 34 that fixes the toner images transferred to the sheet member P by the transfer unit 32 to the sheet member P.

[0027] -Toner image forming unit 30- Multiple toner image forming units 30 are provided to form toner images for each color. In this embodiment, a total of four toner image forming units 30 are provided for yellow (Y), magenta (M), cyan (C), and black (K). In the following description, if it is not necessary to distinguish between yellow (Y), magenta (M), cyan (C), and black (K), the designations Y, M, C, and K will be omitted from the reference numerals.

[0028] Each toner image forming unit 30 is basically configured similarly, except for the toner used, and as shown in Figure 2, it includes a rotating circular image holder 40 and a charger 42 for charging the image holder 40. Furthermore, the toner image forming unit 30 includes an exposure device 44 that irradiates the charged image holder 40 with exposure light to form an electrostatic latent image, and a developing device 46 that develops the electrostatic latent image as a toner image with a developer G containing toner. Thus, each toner image forming unit 30 forms images of each color using toner of each color.

[0029] Furthermore, each colored image holder 40 is in contact with a circulating transfer belt 50 (details will be described later), as shown in Figure 1. In the circulating direction of the transfer belt 50 (see arrows in the figure), the toner image forming units 30 for yellow (Y), magenta (M), cyan (C), and black (K) are arranged in this order from the upstream side.

[0030] -Transfer section 32- As shown in Figure 1, the transfer unit 32 includes a transfer belt 50 and primary transfer rolls 52, each positioned on the opposite side of the image holders 40 of each color from the transfer belt 50, which transfer the toner images formed on the image holders 40 of each color to the transfer belt 50.

[0031] Furthermore, the transfer section 32 includes a winding roll 56 around which the transfer belt 50 is wound, and a drive roll 58 around which the transfer belt 50 is wound and which transmits rotational force to the transfer belt 50. As a result, the transfer belt 50 rotates in the direction of the arrow in the figure.

[0032] Furthermore, the transfer section 32 is positioned on the opposite side of the winding roll 56, with the transfer belt 50 in between, and includes a secondary transfer roll 54 that transfers the toner image transferred on the transfer belt 50 to the sheet member P. A transfer nip NT is formed between the secondary transfer roll 54 and the transfer belt 50, which transfers the toner image to the sheet member P.

[0033] In this configuration, the toner image is first transferred onto the transfer belt 50 by the primary transfer roll 52 in the order of yellow (Y), magenta (M), cyan (C), and black (K). Meanwhile, the toner image is transferred from the transfer belt 50 to the sheet member P, which is transported sandwiched between the transfer belt 50 and the secondary transfer roll 54, by the secondary transfer roll 54. Furthermore, the sheet member P, on which the toner image has been transferred, is transported toward the fuser unit 34.

[0034] - Fixing device 34 - As shown in Figure 1, the fixing device 34 is positioned downstream of the transfer nip NT in the transport direction of the sheet member P. The fixing device 34 heats and pressurizes the toner image transferred to the sheet member P to fix it to the sheet member P.

[0035] [Storage compartments 60, 70] As shown in Figure 1, the storage sections 60 and 70 are located in the lower part of the inside of the main body 10a of the device, and the sheet members P can be loaded inside them. Details of the storage sections 60 and 70 will be described later.

[0036] [Conveying section 14] As shown in Figure 1, the transport unit 14 transports the sheet members P stored in the storage units 60 and 70 along the transport path 16. The storage units 60 and 70 will be described in detail later.

[0037] 〔others〕 As shown in Figure 1, the image forming apparatus 10 is equipped with a number of casters 110 that allow the apparatus body 10a to be easily moved. The casters 110 are attached to the four corners of the lower end of the apparatus body 10a.

[0038] (Main part configuration) Next, the storage sections 60 and 70 and the transport section 14 will be described. The transport section 14 is an example of a sheet transport device.

[0039] [Storage compartments 60, 70] The storage sections 60 and 70 are arranged side by side in the vertical direction of the device, as shown in Figure 3. Storage section 60 is located below storage section 70 and on one side (right side in the figure) in the width direction of the device. In the vertical direction of the device, the lower portion of storage section 60 overlaps with the upper portion of the caster 110.

[0040] In this embodiment, the storage section 60 mainly stores A4-sized sheet members P, and the storage section 70 mainly stores postcard-sized sheet members P. In this image forming apparatus 10, A4-sized sheet members P are consumed the most. Therefore, the number of sheets that can be stored in the storage section 60, which stores the most consumed sheet members P, is made greater than the number that can be stored in the storage section 70. In other words, the thickness of the storage section 60 in the vertical direction of the apparatus is made greater than the thickness of the storage section 70 in the vertical direction of the apparatus.

[0041] [Conveying section 14] As shown in Figure 1, the transport unit 14 is positioned upstream of the transfer nip NT in the transport direction of the sheet member P (hereinafter simply referred to as the "sheet transport direction") and includes an adjustment roll 24 for adjusting the timing of feeding the sheet member P to the transfer nip NT. Furthermore, the transport unit 14 is positioned downstream of the fixing device 34 in the sheet transport direction and includes an discharge roll 26 for discharging the sheet member P on which the toner image has been fixed to the outside of the device body 10a.

[0042] Furthermore, the transport unit 14 includes a delivery roll 20b that sends the sheet members P stored in the storage unit 70 to the transport path 16, and a prevention roll 22b that prevents double feeding of the sheet members P sent out by the delivery roll 20b. The prevention roll 22b is an example of a third transport roll.

[0043] Furthermore, the conveying unit 14 includes a conveying roll 72 positioned between the prevention roll 22b and the adjustment roll 24 in the sheet conveying direction, and a guide plate 76 that guides the sheet member P conveyed by the prevention roll 22b toward the conveying roll 72.

[0044] Furthermore, as shown in Figure 3, the transport unit 14 includes a delivery roll 20a that sends the sheet members P stored in the storage unit 60 to the transport path 16, and a prevention roll 22a that prevents double feeding of the sheet members P sent out by the delivery roll 20a.

[0045] Furthermore, the conveying unit 14 includes a conveying roll 80 positioned between the prevention roll 22a and the conveying roll 72 in the sheet conveying direction, and a guide plate 82 that guides the sheet member P conveyed by the prevention roll 22b toward the conveying roll 72.

[0046] Furthermore, the conveying unit 14 includes guide plates 86, 90, and regulating unit 92 that guide the sheet member P, which is conveyed by the conveying roll 80, toward the conveying roll 72.

[0047] Furthermore, the transport path 16 is divided into two paths upstream of the transport roll 72 in the sheet transport direction. One is the transport path 16a through which the sheet members P loaded in the storage section 60 are transported, and the other is the transport path 16b through which the sheet members P loaded in the storage section 70 are transported.

[0048] -Conveyor Roll 72- The conveying roll 72 is oriented axially in the direction of the depth of the device, and as shown in Figure 3, it is positioned above the housing section 70 in the vertical direction of the device, with a gap between it and the side wall 11 of the device body 10a. The conveying roll 72 is positioned to convey the sheet member P in the vertical direction of the device and comprises a pair of roll sections 72a and 72b. The conveying roll 72 is an example of a second conveying roll, and the vertical direction of the device is an example of a second direction.

[0049] Furthermore, the roll section 72a and the roll section 72b are aligned in the width direction of the device, with the roll section 72a positioned on the side wall 11 side and the roll section 72b positioned on the opposite side of the side wall 11, with the roll section 72a in between. In this embodiment, the roll section 72b is driven, and the roll section 72a is driven by the roll section 72b. The roll section 72b is an example of one roll section, and the roll section 72a is an example of another roll section.

[0050] - Feed roll 20b, prevention roll 22b, guide board 76 - As shown in Figure 3, the delivery roll 20b is positioned to contact the uppermost sheet member P housed in the storage section 70, and is designed to send the uppermost sheet member P to the transport path 16b.

[0051] The prevention roll 22b is positioned below the conveying roll 72 and on one side of the device width direction (right side in the figure) relative to the conveying roll 72. The prevention roll 22b is configured to convey the sheet material P in the device width direction.

[0052] The guide plate 76 is curved so that, when viewed from the depth direction of the device, the side opposite the transport path 16b is convex. The guide plate 76 is designed to guide the sheet member P, which is transported in the width direction of the device by the prevention roll 22b, toward the transport roll 72 that transports the sheet member P in the vertical direction of the device. The guide plate 76 is an example of another guide part.

[0053] - Feed roll 20a, prevention roll 22a, guide board 82 - As shown in Figure 3, the delivery roll 20a is positioned to contact the uppermost sheet member P housed in the storage section 60, and is designed to send the uppermost sheet member P to the transport path 16a.

[0054] The prevention roll 22a is positioned below the conveying roll 72 and on one side of the device width direction relative to the conveying roll 72 (right side in the figure). The prevention roll 22a is configured to convey the sheet material P in the device width direction.

[0055] The guide plate 82 is linear when viewed from the depth direction of the device, and is inclined with respect to the width direction of the device such that one side in the width direction of the device is lower than the other side. The guide plate 82 is designed to guide the sheet member P, which is conveyed in the width direction of the device by the prevention roll 22a, toward the conveying roll 80.

[0056] -Conveyor roll 80, guide board 86, guide board 90, regulating section 92- The conveyor roll 80 has its axial direction in the depth direction of the device, and as shown in Figure 3, it is positioned between the conveyor roll 72 and the prevention roll 22a in the vertical and width directions of the device. The conveyor roll 80 is configured to convey the sheet member P in a first direction that is inclined with respect to the width direction of the device, such that one side in the width direction of the device is lower than the other side. The conveyor roll 80 is an example of a first conveyor roll.

[0057] Here, the frictional force generated between the surface of the conveying roll 80 and the sheet member P is lower than the frictional force generated between the surfaces of the prevention rolls 22a and 22b and the sheet member P, taking life into consideration. In other words, the conveying force of the sheet member P by the conveying roll 80 is weaker than the conveying force of the prevention rolls 22a and 22b. For this reason, it is preferable that the resistance experienced by the sheet member P being conveyed by the conveying roll 80 be small.

[0058] The guide plate 86 is linear when viewed from the depth direction of the device, and is inclined with respect to the width direction of the device such that one side in the width direction of the device is lower than the other side. The guide plate 86 supports the back surface of the sheet member P that is conveyed in the first direction by the conveyor roll 80, and guides the sheet member P so that it is aligned with the first direction.

[0059] The guide plate 90 is curved so that when viewed from the depth direction of the device, the other side in the width direction of the device is convex. Here, as shown in Figure 4, the line extending in the first direction from the part of the conveyor roll 80 where the sheet member P is held is called the first line L1, and the line extending in the vertical direction (second direction) of the device from the part of the conveyor roll 72 where the sheet member P is held is called the second line L2. Then, when viewed from the depth direction of the device, the guide plate 90 is curved so that the side away from the second line L2 in the width direction of the device is convex. In other words, when viewed from the depth direction of the device, the guide plate 90 is curved so that the side facing the conveyed sheet member P is concave. The guide plate 90 is an example of a guide section. Furthermore, point P1 on the guide board 90 that is furthest from the second line L2 is located downstream in the sheet transport direction from point P2 where the guide board 90 intersects with the first line L1.

[0060] The guide plate 90 is positioned to guide the sheet member P by contacting the leading edge of the sheet member P in the region (region R1 in the figure) on the side of the conveyor roll 72 relative to the first line L1 and on the side opposite to where the conveyor roll 80 is positioned relative to the second line L2. In this embodiment, the angle α1 formed by the first line L1 and the second line L2 is 132 degrees.

[0061] Furthermore, viewed from the depth direction of the device, the guide plate 90 is positioned within the area where the conveyor rolls 72 are arranged in the width direction of the device. In other words, viewed from the axial direction of the conveyor rolls 80, the guide plate 90 is positioned within the area where the conveyor rolls 72 are arranged in a direction perpendicular to the axial direction of the conveyor rolls 80 and parallel to the horizontal plane. As a result, within the area where the conveyor rolls 72 are arranged in the width direction of the device, the guide plate 90 contacts at least a portion of the leading edge of the sheet member P, guiding the sheet member P so that its leading edge traces a curved trajectory. In other words, the guide plate 90 contacts at least a portion of the leading edge of the sheet member P, guiding the sheet member P so that its leading edge traces a smooth curved trajectory.

[0062] Specifically, the direction of movement of the leading edge of the conveyed sheet member P changes from a direction inclined to one side with respect to the vertical direction of the device to a direction inclined to the other side with respect to the vertical direction of the device, so that the leading edge of the sheet member P traces a curved trajectory.

[0063] The regulating section 92 is positioned on the opposite side of the transport path 16a from the guide plate 86. As a result, the tip of the regulating section 92 contacts the surface of the sheet member P as it is being transported while in contact with the guide plate 90, thereby regulating the transport position of the sheet member P.

[0064] (action) Next, the operation of the transport unit 14 will be explained. In particular, the process from when the sheet material P loaded in the storage unit 70 is transported to the transport roll 72, and the process from when the sheet material P loaded in the storage unit 60 is transported to the transport roll 72 will be explained. The process from when the sheet material P loaded in the storage unit 60 is transported to the transport roll 72 will be explained in comparison with the transport unit 214 in the comparative configuration.

[0065] [Transportation of sheet material P loaded in storage section 70] In the transport section 14, the delivery roll 20b shown in Figure 3 delivers the uppermost sheet member P loaded in the storage section 70 from the storage section 70 toward the prevention roll 22b. The prevention roll 22b receives the sheet member P from the delivery roll 20b and transports it.

[0066] As shown in Figure 6(A), the sheet member P, which is transported by the prevention roll 22b, is guided along the surface of the curved guide plate 76. Furthermore, as shown in Figures 6(B) and (C), the leading edge of the sheet member P comes into contact with the roll surface of the roll section 72a and is moved by the rotating roll section 72a. The sheet member P is then caught in the transport roll 72 and transported.

[0067] [Configuration of the transport unit 214] The transport unit 214 in the comparative configuration, as shown in Figure 8, is equipped with a transport roll 72, a delivery roll 20b, a prevention roll 22b, and a guide plate 76. Furthermore, the transport unit 214 is equipped with a delivery roll 20a, a prevention roll 22a, a guide plate 82, a transport roll 80, a guide plate 86, a guide plate 290, and a regulating unit 92. In other words, the transport unit 214 is equipped with a guide plate 290, but not with a guide plate 90, compared to the transport unit 14.

[0068] The guide plate 290 has a flat surface that overlaps the second line L2 when viewed from the depth direction of the device, and is designed to guide the sheet member P, whose tip is in contact with the guide plate 290, toward the conveyor roll 72. In other words, the conveyor unit 214 is designed to guide the sheet member P so that it passes through the area (area R2 in the figure) sandwiched between the first line L1 and the second line L2. Area R2 includes the first line L1 and the second line L2.

[0069] [Transportation of sheet material P loaded in storage section 60] In the transport sections 14 and 214, the delivery roll 20a shown in Figures 3 and 8 delivers the uppermost sheet member P loaded in the storage section 60 from the storage section 60 towards the prevention roll 22a. The prevention roll 22a receives the sheet member P from the delivery roll 20a and transports it.

[0070] The prevention roll 22a transports the sheet member P in the width direction of the device. Furthermore, the guide plate 82, which is inclined with respect to the width direction of the device, supports the back surface of the sheet member P being transported by the prevention roll 22a and guides it toward the transport roll 80. The transport roll 80 receives the sheet member P guided by the guide plate 82 and transports it.

[0071] As shown in Figures 5(A) and 9(A), the sheet member P conveyed by the conveyor roll 80 is supported on its back surface by the guide plate 86 and is conveyed at an inclination with respect to the width direction of the device.

[0072] In the transport section 214 of the comparative configuration, as shown in Figure 9(B), the leading edge of the sheet member P, which is transported at an inclination with respect to the width direction of the device, contacts the flat surface of the guide plate 290. Furthermore, as shown in Figure 9(C), the leading edge of the sheet member P moves along the surface of the guide plate 290 in a straight line, thereby guiding the sheet member P toward the transport roll 72 by the guide plate 290.

[0073] Furthermore, the sheet surface at the leading edge of the sheet member P comes into contact with the surface of the guide plate 290, and as shown in Figure 9(D), the sheet member P is guided by the guide plate 290 toward the conveyor roll 72. Then, the leading edge of the sheet member P comes into contact with the clamping portion between the roll section 72a and the roll section 72b, and as shown in Figures 9(E) and (F), the sheet member P is conveyed by the conveyor roll 72.

[0074] In contrast, in the conveying unit 14 according to this embodiment, as shown in Figure 5(B), the leading edge of the sheet member P, which is conveyed at an inclination with respect to the width direction of the device, contacts the curved surface of the guide plate 90. Also, as shown in Figure 5(C), the leading edge of the sheet member P moves along the surface of the guide plate 90 in a curved trajectory, and the sheet member P is guided by the guide plate 90 toward the conveying roll 72. In other words, the leading edge of the sheet member P moves along the surface of the guide plate 90 in a smooth curved trajectory, and the sheet member P is guided by the guide plate 90 toward the conveying roll 72.

[0075] Furthermore, the leading edge of the sheet member P moves along the surface of the guide plate 90 in a curved trajectory, and as shown in Figure 5(D), the sheet member P is guided by the guide plate 90 toward the conveyor roll 72. Also, as shown in Figures 5(E) and 5(F), the leading edge of the sheet member P comes into contact with the roll surface of the roll section 72b and is moved by the rotating roll section 72b. The sheet member P is then caught in the conveyor roll 72 and conveyed. Note that, as shown in Figure 5(E), after the leading edge of the sheet member P separates from the guide plate 90, the guide plate 90 comes into contact with the sheet surface of the sheet member P and guides the sheet member P.

[0076] 〔analysis〕 Next, we will explain the results of an analysis using the finite element method of the resistance that the sheet members P transported from the storage unit 60 receive from the guide plates 90 and 290 in the transport unit 14 and transport unit 214.

[0077] -Analysis Specifications- In the transport section 14 and the transport section 214, the angle α1 between the first line L1 and the second line L2 was set to 132 degrees (see Figure 4). In the conveying sections 14 and 214, the distance M1 in the second direction (vertical direction) from the intersection point K1 of the first line L1 and the second line L2 to the axis of the conveying roll 72 was set to 73 [mm] (see Figure 4).

[0078] In the conveying sections 14 and 214, the distance M2 in the first direction from the intersection point K1 of the first line L1 and the second line L2 to the axis of the conveying roll 80 was set to 42 [mm] (see Figure 4). In the transport section 14, the maximum distance M3 in the device width direction between the curved surface of the guide plate 90 and the second line L2 was set to 12 [mm] (see Figure 4).

[0079] • In the transport section 14, the bending radius (R) of the curved surface of the guide plate 90 was set to 62 mm (see Figure 4). • In the transport section 214, the surface of the guide plate 290 was aligned with the vertical direction of the device (see Figure 8).

[0080] For specifications other than those described above, the same specifications were adopted for the transport unit 14 and the transport unit 214.

[0081] -Analysis conditions- The analysis conditions for the conveying force of the conveying roll 80 were the same for both the conveying unit 14 and the conveying unit 214.

[0082] -Analysis results- The analysis results will be explained using the graph shown in Figure 7. In the graph shown in Figure 7, the vertical axis represents the resistance that the conveyed sheet material P receives from the guide plate, and the horizontal axis represents the elapsed time. The dashed line in the graph shows the analysis results for the conveying unit 14, and the solid line shows the analysis results for the conveying unit 214.

[0083] In the transport section 214, when the leading edge of the sheet member P comes into contact with the guide plate 290, as shown in Figure 9(B), and the direction of movement of the leading edge is abruptly changed, the resistance experienced by the sheet member P increases, as shown by section E1 in the graph.

[0084] Furthermore, in the transport section 214, when the leading edge of the sheet member P contacts the surface of the guide plate 290 and bends, as shown in Figure 9(C), the resistance experienced by the sheet member P increases further and reaches a peak value, as shown by section E2 in the graph.

[0085] Furthermore, in the transport section 214, when the sheet surface at the leading edge of the sheet member P comes into contact with the surface of the guide plate 290, as shown in Figure 9(D), the resistance experienced by the sheet member P decreases, as shown by section E3 in the graph.

[0086] In contrast, in the transport section 14, when the leading edge of the sheet member P comes into contact with the guide plate 90, as shown in Figure 5(B), and the direction of movement of the leading edge is changed, the resistance experienced by the sheet member P increases, as shown by section F1 in the graph.

[0087] However, the distance M4 in the first direction between the position where the tip of the sheet member P contacts the guide plate 90 and the axis of the conveyor roll 80 is longer than the distance M5 in the first direction between the position where the tip of the sheet member P contacts the guide plate 290 and the axis of the conveyor roll 80 (see Figure 9(B)).

[0088] Furthermore, in the conveying section 14, the leading edge of the sheet member P that is in contact with the guide plate 290 moves away from the second line L2 (see Figure 4) that extends in the vertical direction of the device. As a result, the degree of resistance increase in the conveying section 14 is smaller compared to the conveying section 214.

[0089] Furthermore, in the transport section 14, as the leading edge of the sheet member P moves in a curved trajectory while contacting the curved surface of the guide plate 90, and the sheet member P bends as shown in Figure 5(C), the resistance gradually increases as shown by section F2 in the graph.

[0090] Furthermore, in the transport section 14, as the leading edge of the sheet member P moves in a curved trajectory while contacting the curved surface of the guide plate 90, and the sheet member P bends as shown in Figures 5(D) and (E), the resistance, which has been gradually increasing, reaches a peak as shown by section F3 in the graph.

[0091] However, as can be seen by comparing Figures 5(A) to (F) with Figures 9(A) to (F), the distance from the position where the sheet member P is held by the conveyor roll 80 to the position where the sheet member P is in contact with the guide plates 90 and 290 is always longer in the conveyor section 14 than in the conveyor section 214. For this reason, as shown in the graph in Figure 7, the peak resistance in the conveyor section 14 is smaller than the peak resistance in the conveyor section 214.

[0092] (summary) As explained above, in the conveying section 14, the resistance that the conveyed sheet member P receives from the guide plate 90 is smaller compared to the conveying section 214, where the sheet member P passes only within the region R2 sandwiched between the first line L1 and the second line L2.

[0093] Furthermore, in the transport section 14, the guide plate 90 guides the sheet member P so that, when viewed from the depth direction of the device, the side of the sheet member P that moves away from the second line L2 in the width direction of the device is convex. Therefore, compared to the case where the direction of movement of the tip of the sheet member P changes abruptly, the abrupt change in the resistance that the sheet member P receives from the guide plate 90 is suppressed.

[0094] Furthermore, in the conveying section 14, within the area where the conveying rolls 72 are positioned in the width direction of the device, the guide plate 90 moves such that the leading edge of the sheet member P traces a curved trajectory. As a result, the installation range of the guide plate 90 and the conveying rolls 72 in the width direction of the device is narrower compared to the case where the leading edge of the sheet member P moves outside the area where the conveying rolls 72 are positioned in the width direction of the device.

[0095] Furthermore, in the transport section 14, the guide plate 90 is curved so that, when viewed from the depth direction of the device, the side that is away from the second line L2 in the width direction of the device is convex. As a result, compared to the case in which a bend is formed in the guide plate, abrupt changes in the resistance that the sheet member P receives from the guide plate 90 are suppressed.

[0096] Furthermore, in the conveying section 14, the guide plate 90 is positioned within the area where the conveying rolls 72 are located in the width direction of the device. Compared to the case where the guide plate is positioned outside the area where the conveying rolls 72 are located in the width direction of the device, the installation range of the guide plate 90 and the conveying rolls 72 in the width direction of the device is narrowed.

[0097] Furthermore, in the conveying section 14, the leading edge of the sheet member P guided by the guide plate 76 comes into contact with the roll section 72a (solid line in Figure 6(B)). As a result, compared to the case where the leading edge of the sheet member P comes into direct contact with the clamping portion between the roll section 72a and the roll section 72b (dotted line in Figure 6(B)), the bending radius of the sheet member P becomes larger, reducing the resistance that the conveyed sheet member P receives from the guide plate 76.

[0098] Furthermore, in the image forming apparatus 10, compared to the case where a transport unit 214 is provided, the resistance that the sheet member P receives from the guide plate 90 is reduced, thereby suppressing jamming of the sheet member P inside the apparatus body 10a.

[0099] Furthermore, in the image forming apparatus 10, the lower portion of the housing section 60 overlaps with the upper portion of the caster 110 in the vertical direction of the apparatus. As a result, the height of the image forming apparatus 10 is lower compared to the case where the housing section is positioned above the caster 110.

[0100] Although this disclosure has been described in detail with respect to specific embodiments, it will be apparent to those skilled in the art that this disclosure is not limited to such embodiments, and that various other embodiments are possible within the scope of this disclosure. For example, in the above embodiment, the transport unit 14 was used in an electrophotographic image forming apparatus 10, but for example, the transport unit may be used in an image forming apparatus such as an inkjet type.

[0101] Furthermore, in the above embodiment, the guide plate 90 moved such that the tip of the sheet member P traced a curved trajectory, but it is sufficient for the tip of the sheet member P to move within region R1. For example, the tip of the sheet member P may move in a straight line within region R1. However, in this case, the effect achieved by moving the tip in a curved trajectory will not be achieved.

[0102] Furthermore, in the above embodiment, the guide plate 90 moved within region R2 such that the tip of the sheet member P traced a curved trajectory. However, the tip of the sheet member P may move outside region R2. In this case, however, the effect achieved by the movement of the tip of the sheet member P within region R2 will not be achieved.

[0103] Furthermore, in the above embodiment, the guide plate 90 that guides the tip of the sheet member P was a plate-shaped member, but it is not limited to a plate-shaped member, and any member that has a curved surface that the tip of the sheet member P contacts is acceptable. For example, it may be a molded member with a curved surface, curved rods arranged in the depth direction of the device, or a resin film bent into a curved shape.

[0104] Furthermore, in the above embodiment, the guide plate 76 for the tip of the sheet member P was a plate-shaped member, but it is not limited to a plate-shaped member. The sheet member P can be conveyed in such a way that the tip of the sheet member P contacts the roll section 72b. For example, it may be a molded member with a curved surface, curved rods arranged in the depth direction of the device, or a resin film bent into a curved shape. [Explanation of Symbols]

[0105] 10 Image forming apparatus 10a Main unit of the device 12 Image forming unit 14. Conveying section (an example of a sheet conveying device) 22b Prevention roll (an example of a third conveyor roll) 72. Conveyor Roll (Example of a Second Conveyor Roll) 72a Roll section (an example of another roll section) 72b Roll section (an example of a single roll section) 76. Information board (an example of another information display) 80 Conveyor Rolls (Example of the First Conveyor Roll) 90. Information board (an example of an information section) L1 front line L2 second line P Sheet Material R1 area R2 area

Claims

1. A first conveyor roll that conveys the sheet material in the first direction, A second conveyor roll is positioned downstream of the first conveyor roll in the conveying direction of the sheet member, and conveys the sheet member in a second direction which is a different vertical direction from the first direction of the device, and has one roll section positioned on the first conveyor roll side and another roll section that sandwiches the sheet member between the first roll section, A guide portion that contacts the leading edge of the sheet member and guides the sheet member in the region opposite to the first conveyor roll side with respect to a first line extending in the first direction from the portion of the sheet member that is gripped in the second conveyor roll, and in the region opposite to the first conveyor roll side with respect to a second line extending in the second direction from the portion of the sheet member that is gripped in the second conveyor roll, In the second direction, a third conveyor roll is positioned above the first conveyor roll and below the second conveyor roll, and in the width direction of the device, it is positioned on the first conveyor roll side relative to the second conveyor roll, and conveys the sheet member in the width direction of the device. The system includes another guide portion that guides the sheet member so that the leading edge of the sheet member conveyed by the third conveyor roll contacts the roll surface of the other roll portion, Viewed from the axial direction of the first conveyor roll, the intersection point between the surface in which the leading edge of the sheet member contacts the guide portion and the first line is in a region opposite to the second line from the first conveyor roll side. Sheet conveying device.

2. The guide portion guides the sheet member such that, when viewed from the axial direction, the leading edge of the sheet member traces a curved trajectory in which the side away from the second line in the horizontal direction is convex. The sheet conveying device according to claim 1.

3. When viewed from the axial direction, the guide portion guides the sheet member such that the leading edge of the sheet member traces a curved trajectory within the region where the second conveyor roll is located in the width direction of the apparatus. The sheet conveying device according to claim 2.

4. The portion of the guide section that the leading edge of the sheet member contacts is curved so that the side that is horizontally away from the second line when viewed from the axial direction of the first conveyor roll is convex. The sheet conveying device according to claim 1.

5. The second direction is the vertical direction of the device. Viewed from the axial direction, the guide portion is positioned within the region where the second conveying roll is located in a direction perpendicular to the axial direction and parallel to the horizontal plane. The sheet conveying device according to claim 4.

6. A sheet conveying device according to any one of claims 1 to 5, An image forming unit that forms an image on a sheet member conveyed by the sheet conveying device, An image forming apparatus equipped with the following features.

Images