Sheet conveying apparatus and image forming apparatus

Abstract

The present application relates to a sheet conveying device that standardizes a roller unit, and an image forming apparatus. The sheet conveying device includes a housing (11) having an upper layer housing space (160); a paper feeding roller unit (200) having a roller (221) that conveys a sheet, and being detachable with respect to the upper layer housing space (160); and an upper layer conveying guide (155) provided to the housing (11) in a manner that is movable between a closed position that covers at least one side of the upper layer housing space (160) and an open position that opens one side of the upper layer housing space (160).

Description

Technical Field

[0001] The present invention relates to a sheet conveying apparatus and an image forming apparatus, and particularly to a sheet conveying apparatus for conveying sheets and an image forming apparatus having the sheet conveying apparatus. Background Technology

[0002] The image forming apparatus includes a sheet transport device that holds multiple sheets in an overlapping state, and forms an image on the sheets supplied one by one from the sheet transport device. The sheet transport device transports the sheets one by one sequentially, starting from the topmost sheet among the multiple sheets.

[0003] For example, Japanese Patent No. 6676304 discloses a sheet conveying device, characterized by comprising: a device body; a rotating body unit detachable from the device body; and a connecting shaft provided on the device body, capable of connecting the rotating body unit when it is installed on the device body. The rotating body unit includes: a conveying rotating body for conveying sheet in a sheet conveying direction; a guide portion for guiding the sheet; and an engaging portion provided on the guide portion. The guide portion is movable relative to the conveying rotating body between an engaging position where the engaging portion of the device body engages with the engaging portion to guide the sheet and a moving position where it moves from the engaging position. It is also positioned at a position overlapping the conveying rotating body when viewed from the sheet conveying direction. The rotating body unit is held by the guide portion in the moving position and can be detached from or installed on the connecting shaft.

[0004] However, in the sheet conveying device described in Japanese Patent No. 6676304, since the guide portion of the rotating unit guides the sheet, the guide portion must be shaped to suit the sheet. Therefore, in two different models where the sheet shapes differ, the shape of the guide portion must be made to correspond to the shape of that model. Thus, it is impossible to share the rotating unit in two different models. Furthermore, even if a first rotating unit and a second rotating unit can be installed in one sheet conveying device, the first rotating unit and the second rotating unit cannot be shared. Summary of the Invention

[0005] One of the objectives of this invention is to provide a sheet conveying device that standardizes roller units.

[0006] Another object of the present invention is to provide an image forming apparatus that standardizes roller units.

[0007] According to one aspect of the invention, a sheet conveying device includes: a main frame having a storage space; a roller unit having rollers for conveying sheet material and being detachable from the storage space; and a cover disposed on the main frame in such a way that it can move between a closed position covering at least one side of the storage space and an open position opening one side of the storage space.

[0008] According to another aspect of the present invention, an image forming apparatus includes: the sheet conveying device described above; and an image forming unit that forms an image on a sheet conveyed by the sheet conveying device. Attached Figure Description

[0009] Figure 1 This is a perspective view showing the appearance of an MFP according to one embodiment of the present invention.

[0010] Figure 2 This is a side view schematically representing a portion of the internal structure of an MFP.

[0011] Figure 3 This is a cross-sectional view showing an example of the structure of a sheet conveying device.

[0012] Figure 4 This is the first stereoscopic view representing a portion of the MFP.

[0013] Figure 5 This is a second stereoscopic view representing a portion of the MFP.

[0014] Figure 6 This is a three-dimensional view of the paper feed roller unit.

[0015] Figure 7 This is the front view of the upper cover.

[0016] Figure 8 This is a 3D view of the upper cover.

[0017] Figure 9 This is the front view of the lower cover.

[0018] Figure 10 This is a 3D view of the lower cover.

[0019] Figure 11 It is a three-dimensional diagram used to illustrate the loading and unloading of the paper feed roller unit.

[0020] Figure 12 This is the first front view showing the fixing mechanism of the paper feed roller unit.

[0021] Figure 13 This is a side view showing the fixing mechanism of the paper feed roller unit.

[0022] Figure 14 This is the second front view showing the fixing mechanism of the paper feed roller unit.

[0023] Figure 15 This is the third front view showing the fixing mechanism of the paper feed roller unit. Detailed Implementation

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals are used to denote the same parts. Their names and functions are also the same. Therefore, detailed descriptions of them will not be repeated.

[0025] Figure 1 This is a perspective view showing the appearance of an MFP (Multi-Function Peripheral) according to one embodiment of the present invention. The MFP 100 is an example of an image forming apparatus. Figure 1 In this diagram, we define the mutually orthogonal X, Y, and Z directions. The X and Y directions are parallel to the horizontal plane. In the following description, the X direction is parallel to the left and right sides of the MFP100, also called the left-right direction. The direction of the X-direction arrow is the right direction, and the opposite direction is the left direction. The Y direction is parallel to the depth direction of the MFP100, also called the front-back direction. The opposite direction of the Y-direction arrow is the front direction, and the opposite direction is the back direction. The Z direction is parallel to the vertical direction of the MFP100, also called the vertical direction. The direction the Z-direction arrow points is the up direction, and the opposite direction is the down direction.

[0026] Reference Figure 1 The MFP100 has a housing 11 covering the entire MFP100. The housing 11 has an internal space in which an image forming unit 140 forms an image on a sheet based on image data, and a sheet transport device 150 supplies the sheet to the image forming unit 140. The sheet is the recording medium for forming the image. The sheet includes paper, postcards, and OHP (Overhead Projector) sheets. Additionally, the MFP100 has a side door 11A on the left side of the housing 11. The side door 11A can be opened and closed by rotating about a rotation axis arranged in the vertical direction. In the open state (side door 11A open), the internal space of the housing 11 is open to the left. In the closed state (side door 11A closed), the internal space of the housing 11 is not open to the outside.

[0027] Figure 2 This is a schematic side view showing the internal structure of a portion of an MFP. (See reference...) Figure 2Inside the MFP100, the main transport path 41, indicated by the thick dashed line, is formed to extend substantially in the vertical direction. The main transport path 41 is the path used to guide paper transported from the sheet transport device 150 through the image forming unit 140 to the output tray 17. In this example, the lower end 43 of the main transport path 41, located opposite to the upper end 13 above the image forming unit 140, forms a loading inlet for receiving paper from the sheet transport device 150. Additionally, the upper end 13 of the main transport path 41 forms an outlet for discharging the image-formed paper to the output tray 17. An output roller 15 is provided at the upper end 13 of the main transport path 41. The lower end 43 of the main transport path 41 connects to a plurality of secondary transport paths 151a and 152a of the sheet transport device 150, which will be described later.

[0028] The sheet conveying device 150 includes an upper paper supply tray 151 and a lower paper supply tray 152. The upper paper supply tray 151 and the lower paper supply tray 152 are stacked in a sequential arrangement from top to bottom. Figure 2 As shown by the medium-thick dashed line, in the sheet conveying device 150, a secondary conveying path 151a is formed, extending from the upper paper supply tray 151 to the lower end 43 of the main conveying path 41. A secondary conveying path 152a is formed, extending from the lower paper supply tray 152 to the lower end 43 of the main conveying path 41.

[0029] A pickup roller 211, a feed roller 221, and a separation roller 161 are respectively provided corresponding to the upper paper supply tray 151 and the lower paper supply tray 152. The pickup roller 211, feed roller 221, and separation roller 161 corresponding to the upper paper supply tray 151 are located in the secondary conveying path 151a. The pickup roller 211, feed roller 221, and separation roller 161 corresponding to the lower paper supply tray 152 are located in the secondary conveying path 152a.

[0030] In the MFP100, during image formation, a tray containing the sheet to be imaged is selected from the upper feed tray 151 and the lower feed tray 152 as the target tray. The pickup roller 211, feed roller 221, and separation roller 161 corresponding to the selected target tray in the upper feed tray 151 and lower feed tray 152 are activated. Thus, when the upper feed tray 151 is selected as the target tray, the sheet is supplied to the main feed path 41 via the secondary transport path 151a. Similarly, when the lower feed tray 152 is selected as the target tray, the sheet is supplied to the main transport path 41 via the secondary transport path 152a.

[0031] The image forming unit 140 includes image forming units 21Y, 21M, 21C, and 21K for yellow, magenta, cyan, and black, respectively. An image is formed on the sheet by driving at least one of the image forming units 21Y, 21M, 21C, and 21K. When all image forming units 21Y, 21M, 21C, and 21K are driven, a full-color image is formed. Printing data for yellow, magenta, cyan, and black is input to the image forming units 21Y, 21M, 21C, and 21K, respectively. Since the toners processed by the image forming units 21Y, 21M, 21C, and 21K are different, the image forming unit 21Y used to form the yellow image will be described here.

[0032] The image forming unit 21Y includes an exposure head for receiving yellow printing data, a photosensitive drum, a charger, a developer, and a transfer roller 23Y. The exposure head emits a laser based on the received printing data (electrical signal). The emitted laser is scanned in one dimension by a multi-faceted mirror on the exposure head, exposing the photosensitive drum. The direction of the one-dimensional scan of the photosensitive drum is the main scanning direction. After being charged by the charger, the photosensitive drum is irradiated by the laser emitted from the exposure head. This forms an electrostatic latent image on the photosensitive drum. Next, toner is placed on the electrostatic latent image by the developer to form a toner image. The toner image formed on the photosensitive drum is transferred onto the intermediate transfer belt 27 via the transfer roller 23Y.

[0033] On the other hand, the intermediate transfer belt 27 is suspended without slack by the drive roller 24 and roller 24A. When the drive roller 24 rotates counterclockwise in the figure, the intermediate transfer belt 27 rotates counterclockwise in the figure at a predetermined speed. As the intermediate transfer belt 27 rotates, the roller 24A rotates counterclockwise.

[0034] Therefore, image forming units 21Y, 21M, 21C, and 21K sequentially transfer toner images onto the intermediate transfer belt 27. The timing of the toner images transferred by image forming units 21Y, 21M, 21C, and 21K onto the intermediate transfer belt 27 is adjusted by detecting a reference mark attached to the intermediate transfer belt 27. As a result, toner images of yellow, magenta, cyan, and black are superimposed on the intermediate transfer belt 27.

[0035] On the main conveying path 41, a timing roller 45, a transfer roller 47, and a fixing roller 49 are arranged sequentially at intervals from the lower end 43 to the upper end 13. The sheet material supplied from the sheet conveying device 150 to the main conveying path 41 is conveyed to the timing roller 45.

[0036] The timing roller 45 adjusts the conveying state of the sheet in the main conveying path 41 so that the sheet reaches the transfer roller 47 at the same time as the toner image formed on the intermediate transfer belt 27 arrives. The sheet conveyed by the timing roller 45 is pressed against the intermediate transfer belt 27 by the transfer roller 47. By energizing the transfer roller 47, the yellow, magenta, cyan, and black toner images superimposed on the intermediate transfer belt 27 are transferred onto the sheet. The charge on the transfer roller 47 is adjusted to a value suitable for the basis weight of the sheet by controlling the voltage applied to the transfer roller 47 by the CPU (central processing unit).

[0037] A sheet with a toner image transferred onto it is conveyed to a fixing roller 49, where it is heated. The toner melts and is fixed onto the sheet. Afterward, the image-formed sheet is discharged from the upper end 13 of the main transport path 41 onto a paper tray 17 via a paper discharge roller 15. The temperature of the fixing roller 49 is adjusted by a CPU to a value suitable for the sheet's basis weight.

[0038] Figure 3 This is a cross-sectional view showing an example of the structure of a sheet conveying device. Figure 3 This represents a section in a plane perpendicular to the front-back direction of MFP100. (Refer to...) Figure 3 A paper feed roller unit 200 is disposed in the upper storage space 160, which is located above the upper paper feed tray 151. The paper feed roller unit 200 is fixed to the upper paper feed frame 159. The upper paper feed frame 159 is part of the frame 11.

[0039] The paper feed roller unit 200 includes a retainer 201, a pickup roller 211, and a paper feed roller 221. The pickup roller 211 and the paper feed roller 221 are rotatably mounted on the retainer 201. The paper feed roller 221 is rotatably mounted on a paper feed shaft 223. The paper feed shaft 223 is supported on a frame 11 and fixed to the frame 11. The retainer 201 is rotatable about the axis of the paper feed shaft 223. The retainer 201 is subjected to force by an elastic member such as a spring in the downward rotational direction of the pickup roller 211.

[0040] The upper paper supply tray 151 has an upper lifting plate 154 at the bottom. Multiple sheets P are placed on the upper lifting plate 154 in an overlapping state. As the upper lifting plate 154 rises, the top of the multiple sheets P comes into contact with the pick-up roller 211.

[0041] When the upper lifting plate 154 rises further from its position where it abuts against the top of the multiple sheets P, the pick-up roller 211 rises against the elastic force of the elastic member. A sensor is provided to measure the height of the pick-up roller 211, and the rising of the upper lifting plate 154 stops when the pick-up roller 211 reaches a predetermined height. Therefore, in the state where the pick-up roller 211 abuts against the top of the sheet P, the pick-up roller 211 presses the sheet P downwards with a predetermined force. In this state, when the pick-up roller 211 rotates, the topmost sheet of the sheet P is conveyed toward the feed roller 221 due to the friction generated between it and the pick-up roller 211.

[0042] The separating roller 161 is positioned below the feed roller 221 and contacts the feed roller 221. The separating roller 161 is rotatable about a separating shaft 165. The separating shaft 165 is supported by a separating frame shaft. The separating shaft 165 is subjected to an upward force by an elastic body such as a spring. The separating roller 161 is positioned opposite the feed roller 221. When there is no sheet P between the feed roller 221 and the separating roller 161, the separating roller 161 contacts the feed roller 221 and rotates with the feed roller 221. However, a resistance is provided on the separating shaft 165 of the separating roller 161 to limit the rotation of the separating roller 161.

[0043] There are cases where two or more sheets are picked up overlappingly from the upper feed tray 151 by the pick-up roller 211. In this case, the bundle of two or more sheets enters between the feed roller 221 and the separation roller 161. The uppermost sheet P of the two or more sheets contacts the feed roller 221, and the lowermost sheet P contacts the separation roller 161. Here, the case of two sheets P1 and P2 overlapping is described as an example. Let the coefficient of dynamic friction between the feed roller 221 and the uppermost sheet P1 be μ1, the coefficient of static friction between the separation roller 161 and the lowermost sheet P2 be μ2, and the coefficient of static friction between the uppermost sheet P1 and the lowermost sheet P2 be μ3. The outer peripheral surfaces of the feed roller 221 and the separation roller 161 are formed of a material that satisfies the relationships μ1 > μ3 and μ2 > μ3, and are surface treated.

[0044] With multiple sheets P1 and P2 entering between the feed roller 221 and the separation roller 161, a resistance is provided on the separation shaft 165 to restrict the rotation of the separation roller 161. Therefore, a force is generated in sheet P2 in the opposite direction to the conveying direction. Since μ2 > μ3, the separation roller 161 stops rotating when it is in contact with sheet P2. In addition, since μ1 > μ3, the frictional force on sheet P1 from the feed roller 221 overcomes the frictional force on sheet P1 from sheet P2, and sheet P1 is conveyed by the feed roller 42.

[0045] An upper conveyor guide 155 is disposed between the upper paper supply tray 151 and the side door 11A. The upper conveyor guide 155 has an upper inner path surface 157 on the side facing the paper supply roller 221 and an upper outer path surface 158 on the side facing the side door 11A. The side door 11A has a door path surface 12 on the side facing the upper conveyor guide 155. The upper conveyor guide 155 and the side door 11A are disposed at a predetermined interval. The upper outer path surface 158 and the door path surface 12 constitute a part of the secondary conveyor path 152a.

[0046] With the side door 11A open, the upper conveyor guide 155 protrudes to the left of the housing 11, allowing user access. The upper conveyor guide 155 is rotatably connected to the upper guide shaft 156 at its lower portion. The upper guide shaft 156 is fixed to the housing 11 in a parallel position to the front-back direction. The upper conveyor guide 155 moves to a closed position and an open position by rotating about the upper guide shaft 156. Figure 5 The image shows the upper transport guide 155 in the closed position.

[0047] The upper cover 251 is disposed adjacent to the upper conveyor guide 155 to the right (in the direction of the X arrow). When the upper conveyor guide 155 is in the open position, the upper cover 251 is exposed to the left, allowing the user to access the upper cover 251.

[0048] The upper cover 251 has an upper cover path surface 254 facing the upper conveying guide 155. The upper cover path surface 254 is opposite to the upper inner path surface 157 of the upper conveying guide 155. The sheet P1 conveyed by the feed roller 221 travels between the upper inner path surface 157 of the upper conveying guide 155 and the upper cover path surface 254 of the upper cover 251. The upper cover path surface 254 and the upper inner path surface 157 constitute a part of the secondary conveying path 151a.

[0049] The upper cover 251 is rotatably connected to the front cover shaft 255 at its lower portion. The front cover shaft 255 is fixed to the housing 11 in a state parallel to the front-rear direction. The upper cover 251 moves to a closed position and an open position by rotating about the front cover shaft 255. Figure 5 The image shows the upper cover 251 in the closed position. When the upper cover 251 is in the closed position, it covers the left side of the upper storage space 160.

[0050] A lower conveyor guide 155A is disposed between the lower paper supply tray 152 and the side door 11A. The lower conveyor guide 155A has a lower inner path surface 157A on the side facing the paper supply roller 221 and a lower outer path surface 158A on the side facing the side door 11A. The side door 11A has a door path surface 12 on the side facing the lower conveyor guide 155A. The lower conveyor guide 155A and the side door 11A are disposed at a predetermined interval. The lower outer path surface 158A and the door path surface 12 constitute part of a secondary conveyor path. The secondary conveyor path, which is part of the lower outer path surface 158A and the door path surface 12, is the path through which the sheet P discharged from the additional tray added below the lower paper supply tray 152 passes.

[0051] With the side door 11A open, the lower transport guide 155A is exposed to the left of the housing 11, allowing user access. The lower transport guide 155A is rotatably connected to the lower guide shaft 156A at its lower portion. The lower guide shaft 156A is fixed to the housing 11 in a parallel position to the front-back direction. The lower transport guide 155A moves to a closed position and an open position by rotating about the lower guide shaft 156A. Figure 5 The image shows the lower transport guide 155A in the closed position.

[0052] The lower cover 251A is disposed adjacent to the lower conveyor guide 155A to the right above it. When the lower conveyor guide 155A is in the open position, the lower cover 251A is exposed to the left, allowing the user to access the lower cover 251A.

[0053] The lower cover 251A has a lower cover path surface 254A facing the lower conveying guide 155A. The lower cover path surface 254A is opposite to the lower inner path surface 157A of the lower conveying guide 155A. The sheet P1 conveyed by the feed roller 221 travels between the lower inner path surface 157A of the lower conveying guide 155A and the lower cover path surface 254A of the lower cover 251A. The lower cover path surface 254A and the lower inner path surface 157A constitute part of the auxiliary conveying path for the addition. Furthermore, the auxiliary conveying path for the addition is the path through which the sheet stored in the addition tray, which is added below the lower feed tray 152, passes.

[0054] The lower cover 251A is rotatably connected to the front cover shaft 255 at its lower portion. The front cover shaft 255 is fixed to the housing 11 in a state parallel to the front-rear direction. The lower cover 251A moves to a closed position and an open position by rotating about the front cover shaft 255. Figure 5The image shows the lower cover 251A in the closed position. With the lower cover 251A in the closed position, it covers the left side of the lower storage space 160A.

[0055] The upper cover path surface 254 of the upper cover 251 forms part of the secondary conveying path 151a. The lower cover path surface 254A of the lower cover 251A forms part of the secondary conveying path 152a. The secondary conveying paths 151a and 152a have different shapes. Therefore, the upper cover path surface 254 and the lower cover path surface 254A have different shapes, and the upper cover 251 and the lower cover 251A have different shapes.

[0056] Figure 4 This is the first stereoscopic view representing a portion of the MFP. Figure 4 The MFP100 shown indicates the side door 11A is open. With the side door 11A open, the upper conveyor guide 155 and the lower conveyor guide 155A are exposed to the outside of the main body. A door path surface 12 is formed on the inner surface of the side door 11A, forming part of the secondary conveyor paths 151a and 152a and the main conveyor path 41.

[0057] With the side door 11A open, the user can rotate the upper conveyor guide 155 around the upper guide shaft 156. Additionally, the user can rotate the lower conveyor guide 155A around the lower guide shaft 156A.

[0058] Figure 5 This is a second stereoscopic view representing a portion of the MFP. (See reference...) Figure 5 This shows the upper conveyor guide 155 and the lower conveyor guide 155A in their open positions. In this state, the user can access both the upper cover 251 and the lower cover 251A. Figure 5 The image shows the upper cover 251 and the lower cover 251A in their open positions.

[0059] With the upper cover 251 in the open position, the upper storage space 160 is open to the left. Therefore, the user can insert the paper feed roller unit 200 into the upper storage space 160, and can also remove the paper feed roller unit 200 from the upper storage space 160.

[0060] With the lower cover 251A in the open position, the lower storage space 160A opens to the left and outwards. Therefore, the user can insert the paper feed roller unit 200 into the lower storage space 160A, and can also remove the paper feed roller unit 200 from the lower storage space 160A.

[0061] Figure 6 This is a 3D view of the paper feed roller unit. (Refer to...) Figure 6 The paper feed roller unit 200 includes a retainer 201 and an operating lever 230. The retainer 201 includes a connecting portion 201C, a front retaining portion 201A, and a rear retaining portion 201B. The front retaining portion 201A and the rear retaining portion 201B are arranged opposite to each other. The connecting portion 201C is shaped to extend along the Y direction. The connecting portion 201C connects the front retaining portion 201A and the rear retaining portion 201B. The connecting portion 201C, the front retaining portion 201A, and the rear retaining portion 201B may also be formed as a single unit of retainer 201. The front retaining portion 201A has an insertion guide 203 protruding from the front retaining portion 201A on the side opposite to the direction toward the rear retaining portion 201B.

[0062] The front retaining portion 201A and the rear retaining portion 201B respectively support the separating shaft 213. The separating shaft 213 is fixed to the front retaining portion 201A and the rear retaining portion 201B respectively. The separating shaft 213 protrudes from the rear retaining portion 201B on the side opposite to the direction of the rear retaining portion 201B toward the front retaining portion 201A. The pickup roller 211 and the separating gear 215 are arranged between the position where the separating shaft 213 is supported by the front retaining portion 201A and the position where it is supported by the rear retaining portion 201B. The pickup roller 211 and the separating gear 215 are connected to the separating shaft 213 in a state that allows them to rotate around the separating shaft 213. The pickup roller 211 and the separating gear 215 can also be connected to the separating shaft 213 via bearings. The pickup roller 211 and the separating gear 215 are connected. Therefore, the pickup roller 211 rotates as the separating gear 215 rotates.

[0063] The front holding part 201A and the rear holding part 201B are each provided with a through hole through which the paper feed shaft 223 passes. The paper feed shaft 223 is connected to the front holding part 201A and the rear holding part 201B with the through holes of each part passing through them. The front holding part 201A and the rear holding part 201B are connected in a state that allows them to rotate relative to the paper feed shaft 223. Bearings may also be provided in the through holes of the front holding part 201A and the rear holding part 201B. The front holding part 201A and the rear holding part 201B are connected to the paper feed shaft 223 via bearings.

[0064] Based on the rear retaining part 201B, on the opposite side from the direction of the rear retaining part 201B toward the front retaining part 201A, the rear bearing 224B and the mating gear 225 are connected to the paper feed shaft 223. The rear bearing 224B is a bearing, and its inner ring is fixed to the paper feed shaft 223. The mating gear 225 is fixed to the paper feed shaft 223. When the paper feed roller unit 200 is installed in the MFP100, the mating gear 225 meshes with a gear connected to a motor installed in the MFP100. When the rotational force of the motor is transmitted to the mating gear 225, the paper feed shaft 223 rotates. Here, the motor is controlled so that the paper feed shaft 223 rotates in one direction. Here, the direction of rotation of the paper feed shaft 223 is called the forward rotation direction.

[0065] A paper feed roller 221, a first clutch 227, and a second clutch 229 are disposed between the position of the front holding portion 201A and the position of the rear holding portion 201B of the paper feed shaft 223. The paper feed roller 221 is connected to the paper feed shaft 223 in a rotatable state relative to the paper feed shaft 223. The first clutch 227 is a one-way clutch and has a first fixed portion and a first movable portion. The first fixed portion is fixed relative to the paper feed shaft 223, while the first movable portion is not fixed to the paper feed shaft 223. The first movable portion is rotatable about the paper feed shaft 223. The first movable portion is connected to the paper feed roller 221. When the paper feed shaft 223 rotates in the forward direction, the first movable portion transmits power from the first fixed portion. When the paper feed shaft 223 rotates in the opposite direction to the forward direction, the first movable portion does not transmit power from the first fixed portion. The first movable portion can rotate about the paper feed shaft 223 in the forward direction even when the first fixed portion is stopped.

[0066] The distance between the position of the front retaining part 201A supporting the separation shaft 213 and the through hole through which the paper feed shaft 223 passes is the same as the distance between the position of the rear retaining part 201B supporting the separation shaft 213 and the through hole through which the paper feed shaft 223 passes. Therefore, the retainer 201 supports the separation shaft 213 and the paper feed shaft 223 in a parallel state.

[0067] The second clutch 229 is a one-way clutch, having a second fixed portion and a second movable portion. The second fixed portion is fixed relative to the paper feed shaft 223, while the second movable portion is not fixed to the paper feed shaft 223. The second movable portion is rotatable around the paper feed shaft 223. The second movable portion meshes with the connecting gear 217. When the paper feed shaft 223 rotates in the forward direction, the second movable portion transmits power from the second fixed portion. When the paper feed shaft 223 rotates in the opposite direction to the forward direction, the second movable portion does not transmit power from the second fixed portion. The second movable portion can still rotate in the forward direction around the paper feed shaft 223 even when the second fixed portion is stopped.

[0068] The connecting gear 217 is rotatably connected to a shaft extending from the rear retaining portion 201B to the front retaining portion 201A. The connecting gear 217 meshes with the release gear 215 and the second movable part of the second clutch 229. The connecting gear 217 transmits power from the second clutch 229 to the release gear 215.

[0069] When the feed shaft 223 rotates forward, the feed roller 221 and the pickup roller 211 also rotate forward. Sometimes, the feed roller 221 and the pickup roller 211 may slip between themselves and the sheet. In this case, one of them will not rotate due to the action of the first clutch 227 and the second clutch 229. Therefore, even if the sheet slips during the transport of either the feed roller 221 or the pickup roller 211, the sheet can be transported efficiently.

[0070] The operating lever 230 includes a connecting portion 233, a front fixing portion 231, and a rear fixing portion 232. The connecting portion 233 is elongated in the Y direction. The connecting portion 233 has an upper surface and a lower surface that intersect the vertical direction and face opposite directions. The distance between the upper and lower surfaces is less than a predetermined distance. Therefore, the user can hold the connecting portion 233 with two fingers of one hand while gripping the upper and lower surfaces. The connecting portion 233 has multiple grooves parallel to the front-back direction. Therefore, the user can easily press the upper surface of the connecting portion 233 from above with at least one finger.

[0071] The connecting part 233 has a front fixed boss 235 and a rear fixed boss 236 protruding outward at both ends in the Y direction. The front fixed boss 235 and the rear fixed boss 236 are both cylindrical in shape, and their rotational symmetry axis is located on the same straight line parallel to the front and rear directions.

[0072] A front fixing part 231 and a rear fixing part 232 extending in the X direction are respectively connected to both ends of the connecting part 233 in the Y direction. The front fixing part 231 and the rear fixing part 232 are plate-shaped extending from the connecting part 233 in the X direction. The front fixing part 231 and the rear fixing part 232 are each formed with a hole through which the paper feed shaft 223 passes. The front fixing part 231 and the rear fixing part 232 are respectively connected to the paper feed shaft 223 in a rotatable state. The front fixing part 231 and the rear fixing part 232 can also be connected to the paper feed shaft 223 via bearings. Therefore, the operating lever 230 can rotate around the paper feed shaft 223. Therefore, the front fixing boss 235 and the rear fixing boss 236 can rotate around the axis of the paper feed shaft 223.

[0073] Figure 7 This is the front view of the upper cover. Figure 8 This is a 3D view of the upper cover. (Refer to...) Figure 7 and Figure 8The upper cover 251 has an upper cover main body 252, a front cover fixing part 253, and a rear cover fixing part 253A. The front cover fixing part 253 and the rear cover fixing part 253A have shapes that are symmetrical with respect to the XZ plane.

[0074] The upper cover body 252 is a plate-like shape that is longer in the Y direction. The upper cover body 252 has an upper surface that intersects the vertical direction and faces opposite directions, as well as an upper cover path surface 254.

[0075] A front cover fixing part 253 and a rear cover fixing part 253A are connected to the upper cover main body 252 at predetermined intervals in the Y direction. The front cover fixing part 253 and the rear cover fixing part 253A are plate-shaped extending from the upper cover main body 252 in the X direction.

[0076] The front cover fixing part 253 has a front cover shaft 255 protruding forward. The front cover fixing part 253 has a front through hole 257 formed at a predetermined distance from the front cover shaft 255. The front cover fixing part 253 has a front fixing surface 259 facing upward.

[0077] The rear fixing part 253A has a rear shaft 255A that protrudes rearward. The front shaft 255 and the rear shaft 255A are cylindrical, and their respective axes of rotational symmetry are arranged on the same straight line parallel to the Y direction.

[0078] A rear through hole 257A is formed at a predetermined distance from the rear shaft 255A. The distance between the rear shaft 255A and the rear through hole 257A is the same as the distance between the front shaft 255 and the front through hole 257. The rear fixing part 253A has an upward-facing rear fixing surface 259A.

[0079] The front cover shaft 255 and the rear cover shaft 255A are rotatably connected to the housing 11. Therefore, the upper cover 251 can rotate about the respective axes of the front cover shaft 255 and the rear cover shaft 255A, and move between an open position and a closed position.

[0080] Figure 9 This is the front view of the lower cover. Figure 10 This is a 3D view of the lower layer. (Refer to...) Figure 9 and Figure 10 The lower cover 251A has a lower cover main body 252A, a front cover fixing part 253, and a rear cover fixing part 253A. The front cover fixing part 253 and the rear cover fixing part 253A have the same shape as the front cover fixing part 253 and the rear cover fixing part 253A of the upper cover 251. Therefore, their description will not be repeated.

[0081] The lower cover body 252A is a plate-like shape that is longer in the Y direction. The lower cover body 252A has an upper surface that intersects the vertical direction and faces opposite directions, as well as a lower cover path surface 254A. The shape of the lower cover path surface 254A is different from that of the upper cover path surface 254 of the upper cover 251.

[0082] The front shaft 255 and rear shaft 255A of the lower cover 251A are rotatably connected to the housing 11. Therefore, the lower cover 251A can rotate about the respective axes of the front shaft 255 and the rear shaft 255A, and move between the open position and the closed position.

[0083] Figure 11 This is a perspective view illustrating the assembly and disassembly of the paper feed roller unit. (Refer to...) Figure 11 The image shows the upper cover 251 in the open position. Additionally, it shows the paper feed roller unit 200 housed in the upper storage space 160 located below the upper paper feed frame 159.

[0084] The front guide portion 271 and the rear guide portion 272 are fixed to the upper paper feed frame 159. The front guide portion 271 and the rear guide portion 272 are arranged in the Y direction and are symmetrical with respect to the XZ plane. The front guide portion 271 has a front fixing pin 273 protruding towards the rear guide portion 272 on its surface facing the rear guide portion 272. The rear guide portion 272 has a rear fixing pin 274 protruding towards the front guide portion 271 on its surface facing the front guide portion 271. The front fixing pin 273 and the rear fixing pin 274 are cylindrical, and their respective axes of rotational symmetry are located on the same straight line parallel to the Y direction.

[0085] In this state, when the upper cover 251 moves to the closed position, the front retaining pin 273 elastically deforms and enters the front through hole 257, and the rear retaining pin 274 elastically deforms and enters the rear through hole 257A. Thus, the upper cover 251 is positioned relative to the front guide portion 271, and is in the closed position.

[0086] During the movement of the upper cover 251 from the open position to the closed position, the front fixing boss 235 of the operating lever 230 elastically deforms and enters the front through hole 257, and the rear fixing boss 236 elastically deforms and enters the rear through hole 257A. Thus, the operating lever 230 moves together with the upper cover 251, from the holding position to the retracted position. The operating lever 230 rotates about the paper feed shaft 223, and the upper cover 251 rotates about the front shaft 255 and the rear shaft 255A. Therefore, the outer diameters of the front fixing boss 235 and the rear fixing boss 236 are smaller than the inner diameters of the front through hole 257 and the rear through hole 257A.

[0087] Figure 12 This is the first front view showing the fixing mechanism of the paper feed roller unit. Figure 12This is a diagram showing the upper storage space of 160mm from the rear (the direction the Y-direction arrow points). Figure 13 This is a side view showing the fixing mechanism of the paper feed roller unit. Figure 13 This is a diagram showing the upper storage space 160 as viewed from the left (in the direction of the X-shaped arrow). Figure 12 and Figure 13 As an example of the fixing mechanism, the front bearing 224A of the paper feed roller unit 200 will be fixed by the front guide 271 and the front cover fixing part 253. The rear bearing 224B of the paper feed roller unit 200 is fixed by the rear guide 272 and the rear cover fixing part 253A in the same way.

[0088] A portion of each of the front guide portion 271, the front cover fixing portion 253, and the front fixing portion 231 overlaps in the rearward direction (direction indicated by the Y-direction arrow). The front guide portion 271, the front cover fixing portion 253, and the front fixing portion 231 are arranged sequentially in the rearward direction (direction indicated by the Y-direction arrow). The front guide portion 271 is fixed to the upper paper feed frame 159. The front cover shaft 255 of the front cover fixing portion 253 is supported by a front cover bearing 277 formed in the front guide portion 271. The front guide portion 271 is rotatable about the front cover shaft 255. The front guide portion 271 has a stop 279 protruding in the rearward direction (direction indicated by the Y-direction arrow). The front cover fixing portion 253 is positioned in an open position, its rotation range limited by the stop 279. The open position of the upper cover 251 is such that the front cover bearing 277 and the front through hole 257 are approximately horizontal. With the upper cover 251 in the open position, the upper surface of the upper cover body 252 of the upper cover 251 is approximately horizontal. Therefore, the upper cover 251 guides the paper feed roller unit 200, which is loaded and unloaded relative to the upper storage space 160, when it is in the open position.

[0089] The operating lever 230 is rotatable about the paper feed shaft 223. A sliding groove 237 is formed in a portion of the operating lever 230 that contacts the paper feed shaft 223. A lever stop 228, fixed to the front bearing 224A, is disposed in the sliding groove 237. Therefore, the range of rotation of the operating lever 230 is limited by the lever stop 228 and the sliding groove 237. The gripping position of the operating lever 230 is determined by the lever stop 228 and the sliding groove 237. When the operating lever 230 is in the gripping position, the connecting portion 233 of the operating lever 230 is approximately horizontal. Therefore, the user can easily grip the connecting portion 233.

[0090] Figure 14 This is the second front view showing the fixing mechanism of the paper feed roller unit. Figure 14This indicates that the upper cover 251 has moved from the open position to the closed position. Furthermore, when the upper cover 251 moves from the open position to the closed position, the front fixed boss 235 engages with the front through hole 257. As a result, the upper cover 251 engages with the operating lever 230. Then, the operating lever 230 moves as the upper cover 251 rotates. Finally, the upper cover 251 reaches the closed position.

[0091] Figure 15 This is the third front view showing the fixing mechanism of the paper feed roller unit. Figure 15 The diagram shows the upper cover 251 in the closed position. With the upper cover 251 in the closed position, the front retaining pin 273 engages with the front retaining boss 235. Thus, the upper cover 251 is engaged with the front guide portion 271. At this stage, the upper cover 251 is positioned in the closed position, and the operating lever 230 is positioned in the retracted position.

[0092] Furthermore, the front fixing surface 259 of the upper cover 251 abuts against the front bearing 224A. When the upper cover 251 is in the closed position, the front fixing surface 259 is positioned opposite the front fixing surface 275 of the front guide 271. The front fixing surface 259 faces the insertion direction of the paper feed roller unit 200 into the upper storage space 160. Therefore, the upper cover 251, with its front fixing surface 259 abutting against the front bearing 224A, restricts the movement of the paper feed roller unit 200 to the side opposite to the insertion direction. The front bearing 224A is supported in a state where it is clamped by the front guide 271 and the upper cover 251. Thus, the front bearing 224A is positioned, and therefore the paper feed roller unit 200 is positioned within the upper paper feed frame 159.

[0093] During the movement of the upper cover 251 from the closed position to the open position, the operating lever 230 moves along with the upper cover 251. When the operating lever 230 reaches the holding position, its rotation is restricted. During this phase, the operating lever 230 is positioned in the holding position. Furthermore, as the upper cover 251 moves toward the open position, the engagement between the operating lever 230 and the upper cover 251 is released, and the upper cover 251 rotates independently to the open position.

[0094] <Variation Example>

[0095] (1) In the above embodiments, MFP100 was described as an example of an image forming apparatus. An image forming apparatus can be any apparatus capable of forming an image. For example, an image forming apparatus can also be a printer or a fax machine. In addition, a printer can be an apparatus that forms an image using toner or an inkjet printer that forms an image using ink.

[0096] (2) The sheet conveying device 150 is described as part of the MFP100, but it may also be a separate device from the MFP100.

[0097] <Summary of Implementation Methods>

[0098] (Item 1) A sheet conveying device, comprising:

[0099] The main frame includes storage space.

[0100] The roller unit has rollers for conveying sheets and is freely loadable and detachable relative to the aforementioned storage space; and

[0101] The cover is provided on the main frame in such a way that it can move between a closed position covering at least one of the storage spaces and an open position opening the storage space.

[0102] According to this aspect, the roller unit can be freely loaded and unloaded relative to the storage space of the main frame. A cover is provided on the main frame that can move between a closed position covering at least one side of the storage space and an open position opening the storage space. The roller unit can be detached from the storage space when the cover is in the open position. The roller unit can be stored in the storage space when the cover is in the closed position. Since the cover is provided on the main frame, it can be shaped to match the shape of the main frame. The shape of the roller unit is determined independently of the shape of the cover. Therefore, the roller unit can be shared with other types of sheet conveying devices. As a result, a sheet conveying device that standardizes the roller unit can be provided. The housing 11 corresponds to the main frame, the upper storage space 160 and the lower storage space 160A correspond to the storage space, and the paper feed roller unit 200 corresponds to the roller unit. The upper cover 251 and the lower cover 251A correspond to the cover.

[0103] (Item 2) The sheet conveying device according to Item 1, wherein,

[0104] The aforementioned roller unit includes a first roller unit and a second roller unit of the same shape.

[0105] The aforementioned storage space includes a first storage space capable of accommodating the first roller unit and a second storage space capable of accommodating the second roller unit.

[0106] The aforementioned cover includes a first cover that covers the first storage space and a second cover that covers the second storage space.

[0107] The first cover and the second cover have different shapes.

[0108] According to this aspect, the first cover can open and close to accommodate a first storage space for a first roller unit, and the second cover can open and close to accommodate a second storage space for a second roller unit with the same shape as the first roller unit. The first cover and the second cover have different shapes. Therefore, there is no need to distinguish between the first roller unit and the second roller unit, thus making the user's replacement operation easier. The upper storage space 160 corresponds to the first storage space, and the lower storage space 160A corresponds to the second storage space. The paper feed roller unit 200 stored in the upper storage space 160 corresponds to the first roller unit, and the paper feed roller unit 200 stored in the lower storage space 160A corresponds to the second roller unit. The upper cover 251 corresponds to the first cover, and the lower cover 251A corresponds to the second cover.

[0109] (Item 3) The sheet conveying device according to Item 1 or 2, wherein,

[0110] The aforementioned cover has a conveying surface, which forms part of the conveying path through which the sheet conveyed by the aforementioned roller passes.

[0111] According to this aspect, the cover has a conveying surface that forms part of the conveying path. Therefore, it is not necessary to match the shape of the roller unit with the shape of the conveying path. Therefore, the standardization of the roller unit is easy. The upper cover path surface 254 of the upper cover 251 and the lower cover path surface 254A of the lower cover 251A correspond to the conveying surfaces, respectively.

[0112] (Item 4) The sheet conveying device according to any one of items 1 to 3, wherein,

[0113] The cover has a fixing part, which fixes the roller unit housed in the storage space to the main frame when the cover is in the closed position.

[0114] According to this aspect, the fixing part secures the roller unit to the main frame when the cover is in the closed position. Therefore, the user can install the roller unit by opening and closing the cover. Thus, the user's replacement of the roller unit becomes easy. The front fixing surface 259 and rear fixing surface 259A of the upper cover 251 and the lower cover 251A respectively correspond to the fixing part.

[0115] (Item 5) The sheet conveying device according to Item 4, wherein,

[0116] The aforementioned fixing part is provided on the surface facing the insertion direction of the roller unit being inserted into the storage space.

[0117] According to this aspect, the fixing part is provided on the surface facing the insertion direction of the roller unit, so the fixing part abuts against the roller unit from the direction opposite to the insertion direction of the roller unit. Therefore, the roller unit can be easily fixed to the main frame.

[0118] (Item 6) The sheet conveying device according to Item 4 or 5, wherein,

[0119] The aforementioned main frame has a first fixing surface, which faces the opposite direction to the insertion direction of the roller unit into the aforementioned storage space.

[0120] The cover has a second fixing surface, which faces the insertion direction when the cover is in the closed position and is opposite to the first fixing surface.

[0121] According to this aspect, the roller unit's movement in the insertion direction is restricted by a first fixing surface of the main frame, and its movement in the opposite direction to the insertion direction is restricted by a second fixing surface of the cover located in the closed position. Therefore, when the cover component is in the closed position, the movement of the roller unit in a direction parallel to the insertion direction is restricted. Thus, the user can fix the roller unit to the main frame by opening and closing the cover. The front fixing surface 275 of the front guide 271 corresponds to the first fixing surface, and the front fixing surface 259 of the upper cover 251 corresponds to the second fixing surface.

[0122] (Item 7) The sheet conveying device according to any one of items 4 to 6, wherein,

[0123] The aforementioned main frame has a first engaging part.

[0124] The cover has a first engaging portion, which engages with the cover when the cover is in the closed position.

[0125] According to this aspect, when the cover is in the closed position, the first engaging portion engages with the first engaging portion of the main frame. Therefore, the cover in the closed position can be positioned on the main frame. The front fixing pin 273 of the front guide portion 271 corresponds to the first engaging portion, and the front through hole 257 of the upper cover 251 corresponds to the first engaging portion.

[0126] (Item 8) The sheet conveying device according to any one of items 1 to 7, wherein,

[0127] The roller unit also has a holding part, which is provided on the side opposite to the insertion direction of the insertion into the storage space.

[0128] In this respect, the roller unit has a holding part on the side opposite to the insertion direction, so that the user can insert the roller unit into the storage space while holding the holding part. The connecting part 233 of the operating lever 230 is equivalent to the holding part.

[0129] (Item 9) The sheet conveying device according to Item 8, wherein,

[0130] The aforementioned gripping part is movable between a retracted position and a gripping position determined relative to the aforementioned roller, and moves between the retracted position and the gripping position in conjunction with the movement of the aforementioned cover which moves between the aforementioned open position and the aforementioned closed position.

[0131] According to this aspect, the gripping part moves between a retracted position and a gripping position in conjunction with the movement of the cover, which moves between the open and closed positions. Therefore, since the gripping part moves in conjunction with the opening and closing action of the cover, it is possible to move the gripping part to a gripping position that is easy for the user to hold while the cover is in the open position.

[0132] (Item 10) The sheet conveying device according to Item 8 or 9, wherein,

[0133] The aforementioned cover has a second engaging portion.

[0134] The aforementioned gripping part has a second engaging part that engages with the aforementioned second engaging part.

[0135] According to this aspect, since the second engaging portion of the gripping part engages with the second engaging portion of the cover, the gripping part and the cover can move in conjunction with each other during opening and closing. The front through hole 257 of the upper cover 251 corresponds to the second engaging portion, and the front fixing boss 235 of the connecting part 233 corresponds to the second engaging portion.

[0136] (Item 11) An image forming apparatus, comprising:

[0137] The sheet conveying device described in any one of items 1 to 10; and

[0138] The image forming unit forms an image on the sheet conveyed by the sheet conveying device.

[0139] Based on this aspect, it is possible to provide an image forming apparatus that standardizes roller units.

[0140] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the invention is not shown by the foregoing description but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A sheet conveying device, wherein, have: The main frame includes storage space. The roller unit has rollers for conveying sheets and is removable relative to the storage space; as well as The cover is disposed on the main frame in a manner that allows it to move between a closed position covering at least one side of the storage space and an open position opening the other side of the storage space.

2. The sheet conveying device according to claim 1, wherein, The roller unit includes a first roller unit and a second roller unit of the same shape. The storage space includes a first storage space capable of accommodating the first roller unit and a second storage space capable of accommodating the second roller unit. The cover includes a first cover covering the first storage space and a second cover covering the second storage space. The first cover and the second cover have different shapes.

3. The sheet conveying device according to claim 1 or 2, wherein, The cover has a conveying surface that forms part of the conveying path through which the sheet conveyed by the roller passes.

4. The sheet conveying device according to any one of claims 1 to 3, wherein, The cover has a fixing part, which fixes the roller unit stored in the storage space to the main frame when the cover is in the closed position.

5. The sheet conveying device according to claim 4, wherein, The fixing part is disposed on the surface facing the insertion direction of the roller unit into the storage space.

6. The sheet conveying device according to claim 4 or 5, wherein, The main frame has a first fixing surface, which faces the opposite direction to the insertion direction of the roller unit into the storage space. The cover has a second fixing surface, which faces the insertion direction when the cover is in the closed position and is opposite to the first fixing surface.

7. The sheet conveying device according to any one of claims 4 to 6, wherein, The main frame has a first engaging part. The cover has a first engaging portion, which engages with the cover when the cover is in the closed position.

8. The sheet conveying device according to any one of claims 1 to 7, wherein, The roller unit also has a holding part, which is disposed on the side opposite to the insertion direction of the insertion into the storage space.

9. The sheet conveying device according to claim 8, wherein, The gripping part is movable between a retracted position and a gripping position determined relative to the roller, and moves between the retracted position and the gripping position in conjunction with the movement of the cover between the open position and the closed position.

10. The sheet conveying device according to claim 8 or 9, wherein, The cover has a second engaging portion. The holding part has a second engaging part that engages with the second engaging part.

11. An image forming apparatus, wherein, have: The sheet conveying device according to any one of claims 1 to 10; and The image forming unit forms an image on the sheet conveyed by the sheet conveying device.

Images