Sheet feeding device and image forming device

Abstract

To make it easier to recognize that a lock mechanism is in an unlocked condition.SOLUTION: A sheet feeding device is used in a state connected with another unit having a first housing and a first storage part, and comprises a second housing connected to a lower portion of the first housing, a second storage part mounted so as to be pulled out with respect to the second housing, and a lock mechanism which can take a locked condition for locking so that the first housing and the second housing are not separated and an unlocked condition. When the lock mechanism is in the locked condition, the whole of the lock mechanism is positioned outside a moving locus of the first storage part, and when the lock mechanism is in the unlocked condition, the whole of the lock mechanism is not in a state of being positioned outside the moving locus of the first storage part.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a sheet feeding device that feeds sheets and an image forming apparatus that forms images on sheets. [Background technology]

[0002] Image forming apparatuses such as printers, copiers, and multifunction peripherals have sheet storage compartments for storing sheets used as recording materials, and some of these are attached to the housing of the image forming apparatus in a removable manner. To accommodate the increasing capacity of sheet storage compartments and the increasing variety of recording materials, optional feeding devices are often used that can be connected to the bottom of the image forming apparatus body in response to user requests. In some cases, optional feeding devices are used with multiple feeding units stacked vertically for one image forming apparatus body.

[0003] Patent Document 1 describes a sheet feeding device equipped with a locking mechanism that locks the frame of the image forming device body to the frame of the sheet feeding device using a hook that engages with the device body. The locking mechanism in the above document has an operating unit that can be operated to switch the locking mechanism between a locked state and an unlocked state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-114768 Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration of the above document, if a user does not realize that the locking mechanism is in the unlocked state, there is a possibility that the image forming apparatus will be used with the locking mechanism in the unlocked state after installation. Therefore, there has been a demand for a configuration that makes it easy for a user to recognize that the locking mechanism is in the unlocked state.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding device and an image forming apparatus that can easily recognize that a locking mechanism is in an unlocked state. [Means for solving the problem]

[0007] One aspect of the present invention is a sheet feeding device that feeds sheets and is used in connection with another unit having a first housing and a first storage section that stores sheets and is attached to the first housing in a manner that allows it to be pulled out, the sheet feeding device having a second housing connected below the first housing, a second storage section that stores sheets and is attached to the second housing in a manner that allows it to be pulled out, and a locking mechanism that can be in a locked state that locks the first housing and the second housing to prevent them from separating, and an unlocked state that allows the first housing and the second housing to separate, wherein when the locking mechanism is in the locked state, the entire locking mechanism is positioned outside the movement trajectory of the first storage section when the first storage section is attached to and pulled out of the first housing, and when the locking mechanism is in the unlocked state, the entire locking mechanism is configured not to be positioned outside the movement trajectory of the first storage section.

[0008] Another aspect of the present invention is a sheet feeding device that feeds sheets and is used in connection with another unit having a first housing and a first storage section that stores sheets and is attached to the first housing in a manner that allows it to be pulled out, the sheet feeding device having a second housing connected below the first housing, a second storage section that stores sheets and is attached to the second housing in a manner that allows it to be pulled out, and a locking mechanism that can assume a locked state that locks the first housing and the second housing to prevent them from separating, and an unlocked state that allows the first housing and the second housing to separate, wherein the locking mechanism is a locking member having an engaging portion that engages with an engaged portion provided on the first housing, and the locking member has a locking member that is movable so that the engaging portion approaches and moves away from the engaged portion, and the locking member has a contacted portion that comes into contact with the first storage section when the first storage section is moved when the locking member is in a position where the engaging portion is farthest from the engaged portion.

[0009] Another aspect of the present invention is a sheet feeding device that is used in connection with another unit having a first housing and feeds sheets, the sheet feeding device having a second housing connected below the first housing, a storage section that stores sheets and is attached so that it can be pulled out from the second housing, and a locking mechanism that can be in a locked state that locks the first housing and the second housing to prevent separation, and an unlocked state that allows the first housing and the second housing to be separated, wherein when the locking mechanism is in the locked state, the entire locking mechanism is located outside the movement trajectory of the storage section when the storage section is attached to and pulled out from the first housing, and when the locking mechanism is in the unlocked state, the entire locking mechanism is configured not to be located outside the movement trajectory of the storage section. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a sheet feeding device and an image forming apparatus that can easily recognize that the locking mechanism is in an unlocked state. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to a first embodiment. [Figure 2] 1A is a top view of an optional feeding device according to a first embodiment, and FIG. 1B is an enlarged view of a part of the optional feeding device. [Figure 3] FIG. 2 is a perspective view of the optional feeding device according to the first embodiment. [Figure 4] 1A is a perspective view of a locking mechanism according to a first embodiment, and FIG. 1B is a view showing a part of the locking mechanism. [Figure 5] FIG. 2 is an explanatory view of a locking member according to the first embodiment. [Figure 6] FIG. 3 is a view showing a contact portion of the sheet cassette according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing a contact portion of a sheet cassette according to a first modified example. [Figure 8] FIG. 10 is a diagram showing a contact portion of a sheet cassette according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0013] First Embodiment 1 is a schematic diagram showing a cross-sectional configuration of an image forming apparatus 1 according to the first embodiment. The image forming apparatus 1 has a printer unit 50 as an image forming apparatus main body equipped with an image forming section 52, one or more optional feeding devices 200 that supply sheets S to the printer unit 50, and an image reading device 100.

[0014] The optional feeding device 200 functions as a sheet feeding device that feeds sheets S to the printer unit 50, either alone or with multiple optional feeding devices 200 stacked below the printer unit 50. Each optional feeding device 200 is a feeding unit that makes up the sheet feeding device. When the image forming apparatus 1 is equipped with multiple optional feeding devices 200, any one optional feeding device 200 can be called a first feeding unit, and any other optional feeding device 200 can be called a second feeding unit. The configuration of the optional feeding device 200 will be described later.

[0015] The image forming section 52 of this embodiment is an intermediate transfer type electrophotographic unit that includes four process cartridges 5a, 5b, 5c, and 5d that create toner images using four types of toner, namely black, cyan, magenta, and yellow, respectively, and an intermediate transfer unit 4. The image forming section 52 also includes a laser scanner 9 as an exposure device, and a fixing device 15.

[0016] Each of the process cartridges 5a to 5d has a photosensitive drum as an image carrier and one or more process units that act on the photosensitive drum to perform steps in an electrophotographic process, and is detachably mountable to the housing (main housing 51) of the printer unit 50. In this embodiment, the process units of the process cartridges 5a to 5d are, for example, a charging roller as a charging member and a developing roller as a developing member. Each of the process cartridges 5a to 5d also contains one of black, cyan, magenta, and yellow toners used as a developer.

[0017] The laser scanner 9 includes a laser light source and an exposure optical system including a polygon mirror 9a that irradiates the four photosensitive drums with laser light emitted from the laser light source. Note that an LED exposure device in which LEDs are arranged in the main scanning direction (the direction of the rotation axis of the photosensitive drums) may also be used as the exposure device.

[0018] The intermediate transfer unit 4 includes an intermediate transfer belt 4a as an intermediate transfer member, multiple rollers (4b, 4d, 4e) around which the intermediate transfer belt 4a is stretched, a secondary transfer roller 4c, and primary transfer rollers 4f, 4g, 4h, and 4i. In this embodiment, the intermediate transfer belt 4a is stretched around a drive roller 4b, an idler roller 4d, and a tension roller 4e, and is driven to rotate in the direction of arrow A by the drive roller 4b. The primary transfer rollers 4f to 4i are positioned opposite the photosensitive drums of the corresponding process cartridges 5a to 5d, with the intermediate transfer belt 4a sandwiched between them. The secondary transfer roller 4c is positioned so as to sandwich the intermediate transfer belt 4a together with the drive roller 4b (inner secondary transfer roller). A transfer section (secondary transfer section) where a toner image is transferred to the sheet S is formed as a nip between the intermediate transfer belt 4a and the secondary transfer roller 4c.

[0019] The fixing device 15 has a pair of rotors 15a that sandwich and transport the sheet S, and a heating unit that heats the toner image on the sheet S. The pair of rotors 15a is composed of a fixing member (heating member) that heats the toner image, and a pressure member that is pressed against the fixing member. The fixing member and pressure member may be cylindrical rollers, film units with cylindrical film, or belt units in which an endless belt is stretched around multiple rollers. The heating unit may be a ceramic heater with a heating resistor pattern printed on a ceramic substrate, a halogen lamp that emits radiant heat, or an induction heating coil unit that uses electromagnetic induction to heat a conductive layer inside the fixing member.

[0020] The printer unit 50 also has a main body housing 51 that houses the image forming section 52, an internal feeding device 53 arranged within the main body housing 51, a plurality of conveying members (13, 14, 16) that convey the sheets S, and an output tray 17 as a stacking section on which the sheets S are stacked.

[0021] The main body housing 51 includes a metal frame that constitutes the frame of the printer unit 50 and a cover member that forms the exterior surface of the printer unit 50 .

[0022] The internal feeding device 53 includes a sheet cassette 10 that is retractably mounted in the main body housing 51, and a feeding section (11, 12) that feeds sheets S one by one from the sheet cassette 10. The sheet cassette 10 is a sheet storage section (storage cabinet, sheet tray) that stores sheets S. The sheet cassette 10 stores sheets S in a stacked state. The feeding section in this embodiment includes a feeding roller 11 that feeds sheets S from the sheet cassette 10, and a separation roller 12 that comes into contact with the feeding roller 11 to form a separation nip.

[0023] In this embodiment, the plurality of conveying members include a conveying roller pair 13, a registration roller pair 14 disposed immediately before the secondary transfer portion, and a discharge roller pair 16 disposed downstream of a fixing device 15.

[0024] The image reading device 100 has a platen glass on which an original sheet is placed, and a reading unit (image sensor) that reads an image of the original sheet through the platen glass. The image reading device 100 is disposed above the printer unit 50 and is fixed to the top surface of the main body housing 51.

[0025] (Image formation operation) The flow of the image forming operation, which is a series of operations in which the image forming apparatus 1 forms an image on the sheet S while conveying the sheet S one by one, will be described.

[0026] During image formation, the photosensitive drums of the process cartridges 5a to 5d and the intermediate transfer belt 4a are rotated. The surfaces of the photosensitive drums are charged by charging rollers. A laser scanner 9 irradiates the photosensitive drums with laser light based on image information read by the image reading device 100 or image information received from an external computer. This exposes the photosensitive drums, forming electrostatic latent images on their surfaces. A developing roller carries and supplies toner to the photosensitive drums, developing the electrostatic latent images into toner images.

[0027] The toner images formed on the surfaces of the photosensitive drums are primarily transferred onto the intermediate transfer belt 4a by the primary transfer rollers 4f to 4i. At this time, multiple transfer is performed so that the four color toner images are superimposed on each other, forming a full-color toner image on the intermediate transfer belt 4a. The full-color toner image is carried on the intermediate transfer belt 4a and transported toward the secondary transfer unit.

[0028] Meanwhile, sheets S are fed one by one from the in-main body feeding device 53 (or optional feeding device 200). After passing through the separation nip, the sheet S is fed to the registration roller pair 14 via the conveying roller pair 13. The leading edge of the sheet S abuts against the registration roller pair 14, which is in a stopped state, thereby correcting any skew of the sheet S. Thereafter, the registration roller pair 14 feeds the sheet S to the secondary transfer unit in time with the timing at which the toner image is conveyed to the secondary transfer unit. In the secondary transfer unit, the toner image is secondarily transferred from the intermediate transfer belt 4a to the sheet S.

[0029] The sheet S that has passed through the secondary transfer unit undergoes fixing processing in the fixing device 15. The fixing device 15 heats and pressurizes the toner image on the sheet S while nipping and transporting the sheet S at the nip portion (fixing nip) of a pair of rotating bodies 15a. This results in an image fixed on the sheet S. The sheet S that has passed through the fixing device 15 is discharged outside the main body housing 51 by a pair of discharge rollers 16 and is stacked on a discharge tray 17 as a product.

[0030] (Optional feeding device) FIG. 2(a) is a view of the optional feeding device 200 as seen from above. FIG. 2(b) is an enlarged view of a portion 2B of FIG. 2(a). FIG. 3 is a perspective view of the optional feeding device 200. The circle in the upper right corner of FIG. 3 is an enlarged view of a portion of the oblique view. FIGS. 2(a) and 3 show two optional feeding devices 200 stacked one on top of the other, with the sheet cassette 20 of the upper optional feeding device 200 pulled out.

[0031] In the following description and drawings, the vertically downward direction (direction of gravity) when the image forming apparatus 1 is installed on a horizontal surface is referred to as the "downward direction," the vertically upward direction is referred to as the "upward direction," and the downward and upward directions are collectively referred to as the "up-down direction." The horizontal direction perpendicular to the up-down direction, in which the sheet cassette 20 is pulled out (pulling out direction), is referred to as the "front direction." The horizontal direction in which the sheet cassette 20 is inserted (installation direction) is referred to as the "rear direction." The front and rear directions are collectively referred to as the "front-to-rear direction." The horizontal direction, in which the left-hand side when the image forming apparatus 1 or the optional feeding device 200 is viewed from the front, is referred to as the "leftward direction." The horizontal direction, in which the right-hand side when the image forming apparatus 1 or the optional feeding device 200 is viewed from the front, is referred to as the "rightward direction." The leftward and rightward directions are collectively referred to as the "left-to-right direction."

[0032] As shown in Figures 2(a) and 3, each optional feeding device 200 has a housing 220, a sheet cassette 20, a feeding section (Figure 1) including a feeding roller 21 and a separation roller 22, a pair of conveying rollers 23, and a locking mechanism 20L.

[0033] The housing 220 includes a metal frame that constitutes the frame of the optional feeding device 200 and a cover member that forms the exterior surface of the optional feeding device 200.

[0034] The sheet cassette 20 is a sheet storage section (storage cabinet, sheet tray) that stores sheets S. The sheet cassette 20 has a cassette body that is roughly box-shaped and open at the top. A storage space for the sheets S is formed inside the cassette body, and the sheets S are stored in a stacked state. The sheet cassette 20 also has a regulating member that regulates the position of the sheets S, and a lifting plate (middle plate) that supports the lower surfaces of the stacked sheets S and raises and lowers the sheets S.

[0035] The sheet cassette 20 is attached to the housing 220 so as to be removable. That is, the sheet cassette 20 is movable between a removed position (the position in FIG. 2(a) , the position of the upper sheet cassette 20 in FIG. 3 ) where it is removed from the housing 220, and an attached position (the position of the lower sheet cassette 20 in FIG. 3 ) where it is attached to the housing 220. The housing 220 has a guide portion (guide rail) that guides the guided portion of the sheet cassette 20 so that the sheet cassette 20 slides in a sliding direction substantially parallel to the front-rear direction relative to the housing 220.

[0036] When the sheet cassette 20 is in the pulled-out position, at least a portion of the storage space of the sheet cassette 20 is exposed to the outside of the housing 220, allowing the user to replenish or replace the sheets S. When the sheet cassette 20 is in the pulled-out position, the optional feeding device 200 can perform a feeding operation to feed the sheets S from the sheet cassette 20, and the image forming apparatus 1 can perform an image forming operation on the sheets S fed from the sheet cassette 20.

[0037] The feeding unit of this embodiment includes a feed roller 21 that feeds a sheet S from a sheet cassette 20, and a separation roller 22 that contacts the feed roller 21 to form a separation nip. The separation roller 22 applies a frictional force to the sheet S in the direction opposite to the sheet feeding direction at the separation nip, thereby preventing sheets S other than the uppermost sheet S from passing through the separation nip when multiple sheets S enter the separation nip. In other words, the feeding unit feeds sheets S one by one from the sheet cassette 10. The above feeding unit is an example, and for example, a pickup roller that unwinds a sheet S from the sheet cassette 20 toward the feed roller 21 may be added upstream of the feed roller 21. The separation roller 22 is an example of a separating member that separates the sheets S, and for example, a pad-shaped friction member (rubber pad) that contacts the feed roller 21 may be used as the separating member.

[0038] The conveying roller pair 23 is disposed at a discharge port 222, which is an opening provided in the upper surface 221 of the housing 220. The conveying roller pair 23 is also disposed on a conveying path that penetrates from the lower surface of the housing 220 to the upper surface 221. Therefore, the conveying roller pair 23 shown in Figures 2(a) and 3 can convey not only the sheet S fed from the upper sheet cassette 20, but also the sheet S fed from the lower sheet cassette 20.

[0039] In the image forming operation described above, a feeding operation will be described when the sheet cassette 20 of the optional feeding device 200 is used as the supply source of the sheets S. First, the sheets S stored in the sheet cassette 20 are fed by the feeding roller 21 rotating counterclockwise in FIG. 1. One sheet S that has passed through the separation nip is carried by the conveying roller pair 23 through the discharge port 222 and the receiving port of the printer unit 50 into the conveying path within the printer unit 50, and is conveyed toward the conveying roller pair 13. The operation thereafter is the same as when the sheet S is fed from the in-main body feeding device 53.

[0040] (Configuration of the top surface of the case) 3, a configuration for connecting to the printer unit 50 or another optional feeder 200 is arranged on the upper surface 221 of the housing 220 of the optional feeder 200. The upper surface 221 of the housing 220 is the surface that faces the lower surface of the printer unit 50 to which the optional feeder 200 is connected, or the lower surface of another optional feeder 200 to which the optional feeder 200 is connected.

[0041] In this embodiment, on an upper surface 221 of the housing 220, positioning pins 201, 202, 203, locking members 204, 205, 206, the above-mentioned outlet 222, and a connector 223 are arranged.

[0042] The pins 201 to 203 are positioning shapes that determine the relative positions of the printer unit 50 and the optional feeder 200. The pins 201 to 203 each protrude upward. The underside of the main body housing 51 of the printer unit 50 has upwardly recessed holes formed at positions corresponding to the pins 201 to 203.

[0043] When the printer unit 50 is placed on the optional feeder 200, the pins 201 to 203 as engaging portions engage with the hole shapes as engaged portions, respectively. This determines the relative positions of the printer unit 50 and the optional feeder 200 in the front-to-back direction (arrow Y) and the left-to-right direction (arrow X). In addition, the bottom surface of the housing 220 of the optional feeder 200 also has hole shapes recessed upward at positions corresponding to the pins 201 to 203. This allows the optional feeder 200 to be stacked on top of another optional feeder 200,

[0044] Although an example in which the engaging portion is a pin (convex portion) and the engaged portion is a hole-shaped (concave portion) has been described here, the engaging portion may be a hole-shaped (concave portion) and the engaged portion may be a pin (convex portion) that engages with the hole-shaped portion. Furthermore, the shapes of the convex portion and the concave portion are not limited to a pin (shaft-shaped member) extending in the up-down direction and a cylindrical hole, but may be any shape that can restrict the relative movement between the printer unit 50 and the optional feeder device 200 in at least one of the front-rear direction and the left-right direction.

[0045] In this embodiment, pins 201-203 are arranged in a total of three locations: two locations at the front and rear of the right side of the housing 220 and one location at the rear left side. This allows the relative positions of the printer unit 50 and the optional feeding device 200 to be determined accurately. Furthermore, pins 201-203 are arranged in two locations at the front and rear of the right side of the housing 220 where the discharge outlet 222 for sheets S is located. This improves the positional accuracy of the discharge outlet 222 relative to the inlet of the printer unit 50 or another optional feeding device 200, and allows sheets S to be more smoothly transferred from the optional feeding device 200. However, the number and locations of pins 201-203 (engaging portions) and hole shapes (engaged portions) may be changed as appropriate depending on the specific configuration of the image forming apparatus 1.

[0046] The connector 223 is connected to a main body-side connector provided on the printer unit 50. The optional feeder 200 is electrically connected to a circuit within the printer unit 50 via the connector 223, and can receive power and control signals. A connector insertion section shaped to be engageable with the connector 223 is disposed on the underside of the housing 220 of the optional feeder 200. Therefore, when the optional feeder 200 is stacked on top of another optional feeder 200, the connector 223 and the connector insertion section are connected, and the lower optional feeder 200 is electrically connected to the printer unit 50 via the upper optional feeder 200.

[0047] The locking members 204 to 206 are arranged so as to protrude upward from the top surface 221 of the housing 220. In this embodiment, the locking members 204 to 206 are arranged at a total of three locations: two locations on the left and right ends of the front side of the housing 220, and one location approximately in the center of the rear of the housing 220. At least one of the locking members 204 to 206 is arranged so that the movement area when the sheet cassette 20 is pulled out and inserted overlaps with the movable area B (FIG. 2(b)) of the locking member.

[0048] The locking members 204 to 206 are part of a locking mechanism 20L that locks the printer unit 50 and the optional feeding device 200. Details of the locking mechanism 20L and the fact that the movable range of the locking members overlaps with the movable range of the sheet cassette 20 will be described in detail below.

[0049] (locking mechanism) Next, the locking mechanism 20L according to this embodiment will be described. Fig. 4(a) is a perspective view of the locking mechanism 20L. Fig. 4(b) is a front view of a portion of the locking mechanism 20L seen from the front side. Fig. 5 is a schematic diagram showing the movable range of the locking member 204.

[0050] As shown in FIG. 4( a ), the locking mechanism 20 L includes locking members 204 to 206 , an operating lever 210 , a slider 211 , and a connecting rod 212 .

[0051] 5, the locking member 204 has a claw portion 214 (hook portion) as an engaging portion that engages with the printer unit 50 or another optional feeder 200. The printer unit 50 is provided with an engaged portion 215 that engages with the claw portion 214. The engaged portion 215 is a part of the main body housing 51, and is formed by a part of the frame of the printer unit 50 or a member fixed to the frame. The housing 220 of the optional feeder 200 is also provided with an engaged portion that engages with the claw portion 214.

[0052] 5 shows only one locking member 204, the other locking members 205 and 206 also have a claw portion 214 similar to that of the locking member 204. In addition, the printer unit 50 and the other optional feeder 200 are provided with an engaged portion that engages with the claw portion 214 of the locking member 205 and an engaged portion that engages with the claw portion 214 of the locking member 206.

[0053] The locking members 204 to 206 are movable between an engagement position (locking position, solid line in FIG. 5) where the claw portion 214 engages with the engaged portion 215, and a disengagement position (release position, dashed line in FIG. 5) where the claw portion 214 disengages from the engaged portion 215. In other words, the locking members 204 to 206 are movable so that the claw portion 214 approaches and moves away from the engaged portion 215. A state in which the locking members 204 to 206 are in the engagement position is called the locked state of the locking mechanism 20L, and a state in which the locking members 204 to 206 are in the disengaged position is called the unlocked state of the locking mechanism 20L.

[0054] In this embodiment, the locking members 204, 205, and 206 move between the engagement position and the disengagement position by rotating around the rotation shafts 204b, 205b, and 206b (FIG. 4(a)), respectively. In this embodiment, the axial directions of the rotation shafts 204b, 205b, and 206b are all along the direction in which the sheet cassette 20 is inserted and removed (the front-to-rear direction of the device). Note that some or all of the locking members 204 to 206 may move between the engagement position and the disengagement position by, for example, linear movement (sliding) without rotating.

[0055] The slider 211 is elongated and extends in the left-right direction of the device. The slider 211 is supported by the housing 220 so as to reciprocate (slide) in a slide direction C that intersects with the pull-out direction of the sheet cassette 20. In this embodiment, the slider 211 reciprocates in the left-right direction. A drive unit 211a that drives the locking member 204 is provided at one end of the slider 211, and a drive unit 211b that drives the locking member 205 is provided at the other end of the slider 211. In this embodiment, the drive units 211a and 211b are rack-shaped and engage with gears provided on the rotation shafts 204b and 205b. The drive units 211a and 211b do not have to be rack-shaped as long as they are shaped so as to abut against the corresponding locking member or a member that moves integrally with the locking member to move the locking member between the engaged position and the disengaged position.

[0056] Because the upper and lower positions of drive units 211a and 211b are different, the rotation direction of locking member 204 and the rotation direction of locking member 205 are always opposite. In other words, when slider 211 is slid leftward from the state shown in Figure 4(a), locking members 204 and 205 move from the engaged position to the disengaged position by tilting toward the center in the left-right direction. Thereafter, when slider 211 is slid rightward, locking members 204 and 205 move up toward the left and right, respectively, by tilting toward the center, and move from the disengaged position to the engaged position.

[0057] The connecting rod 212 is elongated and extends in the front-to-rear direction of the device. One end of the connecting rod 212 is provided with a gear 212a that meshes with a rack portion 211c provided on the slider 211. The other end of the connecting rod 212 is a rotation shaft 206b of the locking member 206. Due to the meshing of the rack portion 211c and the gear 212a, the connecting rod 212 rotates as the slider 211 moves, and further, the locking member 206 rotates together with the connecting rod 212 between the engaged position and the disengaged position. As long as the locking member 206 can be moved between the engaged position and the disengaged position in response to the operation of the operating lever 210, the configuration is not limited to one in which the locking member 206 is moved via the rack portion 211c, the gear 212a, and the connecting rod 212.

[0058] The operating lever 210 is an operating unit that can switch the locking mechanism 20L between a locked state and an unlocked state. In this embodiment, the operating lever 210 is integrally formed with a slider 211. The operating lever 210 and the slider 211 can move left and right between a locked position, where the locking mechanism 20L is locked, and an unlocked position, where the locking mechanism 20L is unlocked.

[0059] With the sheet cassette 20 pulled out (FIG. 3), the user can operate the locking mechanism 20L by gripping and moving the operating lever 210 left and right. Specifically, when the user moves the operating lever 210 leftward, each of the locking members 204 to 206 moves from the engaged position to the disengaged position, and the locking mechanism 20L changes from the locked state to the unlocked state. Conversely, when the user moves the operating lever 210 rightward, each of the locking members 204 to 206 moves from the disengaged position to the engaged position, and the locking mechanism 20L changes from the unlocked state to the locked state.

[0060] In the locked state, the locking members 204 to 206 of the locking mechanism 20L engage with the engaged portions 215 (FIG. 5) of the printer unit 50, thereby restricting the printer unit 50 from being separated (detached) upward from the optional feeder 200. In the unlocked state, the locking members 204 to 206 are disengaged from the engaged portions 215 (FIG. 5) of the printer unit 50, allowing the printer unit 50 to be separated (detached) upward from the optional feeder 200.

[0061] When another optional feeding device 200 is connected to the upper level of the optional feeding device 200, the locking mechanism 20L in the locked state prevents the upper level optional feeding device 200 from being separated (detached) upward from the lower level optional feeding device 200. Furthermore, the locking mechanism 20L in the unlocked state allows the upper level optional feeding device 200 to be separated (detached) upward from the lower level optional feeding device 200.

[0062] The shape of claw portion 214 of locking members 204-206, the position of the rotation center, and the shape of engaged portion 215 are set so that when an upward force is applied to claw portion 214 of the locking member in the engaged position, the locking member will not move to the disengaged position. For example, suppose that in the state shown in FIG. 5, a user attempts to lift printer unit 50 upward, causing engaged portion 215 to press claw portion 214 upward. At this time, the force received by claw portion 214 causes a moment around pivot axis 204b acting on locking member 204 in direction R1, which moves locking member 204 from the disengaged position to the engaged position. This prevents locking members 204-206 from moving to the disengaged position and unintentionally releasing the lock between devices.

[0063] (Contact area of ​​sheet cassette) Incidentally, the image forming apparatus 1 of this embodiment is assumed to be used after connecting the printer unit 50 to the optional feeding device 200 and locking the locking mechanism 20L during installation. If the image forming apparatus 1 is used with the locking mechanism 20L in the unlocked state, the stability (resistance to tipping) of the printer unit 50 when an external force is applied to the apparatus will be reduced compared to the original design.

[0064] Therefore, there has been a demand for a configuration that allows easy recognition that the lock mechanism 20L is in the unlocked state.

[0065] In particular, in this embodiment, the operation lever 210 is disposed inside the optional feeding device 200 in order to reduce the size of the device. In other words, when viewed from the front side of the device with the sheet cassette 20 closed, the operation lever 210 is in a position where it is covered by the front cover 20F (FIG. 3) of the sheet cassette 20. For this reason, if the user completes the installation work without realizing that the operation lever 210 is in the detached position during installation of the device, the image forming device 1 will be used with the lock mechanism 20L in the unlocked state.

[0066] Therefore, in this embodiment, as described below, the sheet cassette 20 is provided with a contact portion 20a that comes into contact with a portion of the locking mechanism 20L when the sheet cassette 20 is pulled out or attached to the housing 220 while the locking mechanism 20L is in the unlocked state. In this embodiment, when the locking mechanism 20L is in the unlocked state, the contact between the contact portion 20a and a portion of the locking mechanism 20L prevents the sheet cassette 20 from being pulled out or attached to the housing 220.

[0067] 6 is a diagram showing a contact portion 20a provided on the sheet cassette 20. When viewed in the movement direction of the sheet cassette 20 (the front-to-rear direction of the device), the contact portion 20a in this embodiment is arranged in a position overlapping with the locking member 204 in the disengaged position in the lower optional feeding device 200. In other words, at least a portion of the locking member 204 in the disengaged position enters the movement trajectory (the space through which the sheet cassette 20 passes) of the upper sheet cassette 20 when it is inserted into or extracted from the housing 220. In other words, the contact portion 20a of the upper sheet cassette 20 is arranged to come into contact with the locking member 204 when the upper sheet cassette 20 is moved while the locking mechanism 20L in the lower optional feeding device 200 is in the unlocked state.

[0068] In other words, the upper optional feeding device 200 (first feeding unit) has a housing 220 (first housing) and a sheet cassette 20 (first storage section). The lower optional feeding device 200 (second feeding unit) has a housing 220 (second housing) connected below the upper housing 220, a sheet cassette 20 (second storage section), and a locking mechanism 20L. The locking mechanism 20L can be in a locked state in which the upper and lower housings 220 (first and second housings) are locked to prevent separation, and in an unlocked state in which the upper and lower housings 220 are allowed to separate. The sheet cassette 20 (first storage section) of the upper optional feeding device 200 has a contact portion 20a that comes into contact with a part of the locking mechanism 20L when the sheet cassette 20 (first storage section) is moved when the locking mechanism 20L is in the unlocked state.

[0069] In this way, when the lock mechanism 20L is in the unlocked state, the entire lock mechanism 20L is configured not to be positioned outside the movement trajectory of the upper sheet cassette 20 (first storage section). In other words, when the lock mechanism 20L is in the unlocked state, a part of the lock mechanism 20L is always inside the movement trajectory of the upper sheet cassette 20 (first storage section). This configuration makes it easier for the user to recognize that the lock mechanism 20L is in the unlocked state.

[0070] The locking member 204 also has a contacted portion 204a that comes into contact with the contact portion 20a of the sheet cassette 20. The contacted portion 204a is the portion that comes into contact with the sheet cassette 20 when the upper sheet cassette 20 (first storage section) is moved while the locking member 204 is in the position where the claw portion 214 (engaging portion) is furthest from the engaged portion 215 (the broken line position in FIG. 5, the position in FIG. 6). This configuration makes it easier for the user to recognize that the locking mechanism 20L is in the unlocked state.

[0071] When the locking member 204 is in the engaged position, the upper sheet cassette 20 does not overlap with the locking member 204 when viewed in the movement direction of the upper sheet cassette 20 (the front-to-rear direction of the device). In other words, the locking member 204 in the engaged position is retracted from the movement trajectory of the upper sheet cassette 20 when it is inserted into or extracted from the housing 220. In other words, when the locking mechanism 20L is in the locked state, the entire locking mechanism 20L is located outside the movement trajectory of the sheet cassette 20 when the upper sheet cassette 20 (first storage section) is inserted into or extracted from the housing 220 (first housing). Therefore, when the locking mechanism 20L in the lower optional feeding device 200 is in the locked state, the upper sheet cassette 20 can move without interfering with any part of the locking mechanism 20L.

[0072] In this embodiment, the contacted portion 204a of the locking member 204 is a convex portion that protrudes upward when the locking member 204 is in the disengaged position. In particular, the contacted portion 204a in this embodiment protrudes upward further than the tip of the claw portion 214 when the locking member 204 is in the disengaged position. The contacted portion 204a is disposed in a position closer to the pivot shaft 204b than the claw portion 214. Because the force from the sheet cassette 20 is received by the contacted portion 204a, which is closer to the pivot shaft 204b than the claw portion 214, the possibility of deformation or damage to the locking member 204 can be reduced compared to when the force from the sheet cassette 20 is received by, for example, the claw portion 214.

[0073] In this embodiment, contact portions 20a are arranged at two locations, at the front and rear ends of the cassette body of the sheet cassette 20. As shown in Fig. 6, consider a case where a user attempts to pull out the sheet cassette 20 of the upper optional feeding device 200 from the housing 220 when the locking member 204 of the lower optional feeding device 200 is in the disengaged position. In this case, the contact portion 20a (first contact portion) at the front end of the sheet cassette 20 comes into contact with the locking member 204 of the lower optional feeding device 200, preventing the sheet cassette 20 from being pulled out.

[0074] Also, consider a case where the user attempts to attach sheet cassette 20 of upper optional feeding device 200 to housing 220 when locking member 204 of lower optional feeding device 200 is in the disengaged position. In this case, contact portion 20a (second contact portion) at the rear end of sheet cassette 20 comes into contact with locking member 204 of lower optional feeding device 200, preventing sheet cassette 20 from being attached.

[0075] As described above, in this embodiment, the contact portions 20a (first contact portion, second contact portion) are arranged on the upstream side and downstream side in the pull-out direction of the sheet cassette 20 (storage portion, first storage portion). As a result, the contact portions 20a come into contact with the locking member 204 during both the pull-out and installation operations of the sheet cassette 20.

[0076] In this way, the user can become aware that the lock mechanism 20L is in the unlocked state when the sheet cassette 20 cannot be normally pulled out or installed (cassette opening and closing operation).

[0077] That is, according to this embodiment, it is possible to provide a sheet feeding device and an image forming apparatus that can easily recognize that the locking mechanism 20L is in the unlocked state. Furthermore, according to this embodiment, it is possible to prevent the image forming apparatus 1 from being used with the locking mechanism 20L in the unlocked state, and to ensure that the image forming apparatus 1 is used in a state where it exhibits its inherent stability.

[0078] (Variation 1) 6 illustrates a configuration in which contact portion 20a arranged on sheet cassette 20 of upper optional feeder 200 comes into contact with locking member 204 of lower optional feeder 200. However, this is not limiting, and as shown in FIG. 7, contact portion 10a that can come into contact with locking member 204 of upper optional feeder 200 may be arranged on sheet cassette 10 of printer unit 50. In this case, if sheet cassette 10 is pulled out or installed while locking mechanism 20L of uppermost optional feeder 200 is in the unlocked state, contact portion 10a will come into contact with the contacted portion, preventing installation or removal of sheet cassette 10.

[0079] That is, the printer unit 50 (image forming apparatus main body) has a main body housing 51 (first housing) and a sheet cassette 10 (first storage section) that stores sheets and is attached to the main body housing 51 so as to be removable (FIG. 1). The upper optional feeding device 200 (feeding unit) has a housing 220 (second housing) connected below the main body housing 51, a sheet cassette 20 (second storage section) that stores sheets and is attached to the housing 220 so as to be removable, and a locking mechanism 20L. The locking mechanism 20L can be in a locked state that locks the main body housing 51 and the housing 220 (first housing and second housing) so that they cannot be separated, and an unlocked state that allows the main body housing 51 and the housing 220 to be separated. The sheet cassette 10 (first storage section) of the printer unit 50 has a contact portion 10a that comes into contact with a part of the locking mechanism 20L when the sheet cassette 10 is moved when the locking mechanism 20L is in the unlocked state.

[0080] As in the first embodiment, this modification also makes it easier for the user to recognize that the lock mechanism 20L is in the unlocked state. Note that, as in the first embodiment, the contact portions 10a (first and second contact portions) may be arranged in two locations, one on the front side and one on the rear side of the sheet cassette 10.

[0081] (Variation 2) 8, the contact portion 20a arranged on the sheet cassette 20 may be configured to come into contact with the locking member 204 of the optional feeding device 200 to which the sheet cassette 20 belongs. For example, the contact portion 20a of the sheet cassette 20 of the lower optional feeding device 200 may be configured to come into contact with the contacted portion 204a of the locking member 204 of the lower optional feeding device 200.

[0082] That is, the optional feeding device 200 (feeding unit) has a housing 220 that can be connected to the printer unit 50 (image forming apparatus main body) or another optional feeding device 200 (another feeding unit) in the sheet feeding device. The optional feeding device 200 (feeding unit) also has a sheet cassette 20 (storage section) that stores sheets and is attached to the housing 220 so that it can be pulled out, and a locking mechanism 20L. The locking mechanism 20L can be in a locked state that locks the housing 220 and the printer unit 50 or another optional feeding device 200 so that they cannot be separated, and an unlocked state that allows them to be separated. The sheet cassette 20 (storage section) has a contact portion 20a that comes into contact with a part of the locking mechanism 20L when the sheet cassette 20 is moved when the locking mechanism 20L is in the unlocked state.

[0083] As in the first embodiment, this modification also makes it easier for the user to recognize that the lock mechanism 20L is in the unlocked state. Note that, as in the first embodiment, the contact portions 20a (first and second contact portions) may be arranged in two locations, one on the front side and one on the rear side of the sheet cassette 20.

[0084] (Other variations) For example, the contact portions 20a may be arranged on both the left and right sides of the sheet cassette 20, and the two contact portions 20a may come into contact with the left and right lock members 204, 205.

[0085] Furthermore, the object that the contact portion 20a comes into contact with may be a portion other than the locking members 204 to 206 of the locking mechanism 20L. For example, a protrusion may be provided on the slider 211 or the connecting rod 212 (FIG. 4(a)) as the contacted portion, so that the contact portion 20a comes into contact with the protrusion when the sheet cassette 20 is pulled out or installed while the locking mechanism 20L is in the unlocked state.

[0086] (Other embodiments) In the above-described embodiment, the image forming apparatus 1 is exemplified as including an intermediate transfer type electrophotographic unit as the image forming section 52. However, the image forming section 52 is not limited to this, and may be, for example, a direct transfer type electrophotographic unit that transfers a toner image directly from a photosensitive drum to a sheet S without using an intermediate transfer body. Furthermore, the image forming section 52 may be an image forming unit (printing unit) other than an electrophotographic type, such as an inkjet type. [Explanation of symbols]

[0087] 10...first storage section (sheet cassette) / 20...storage section, first storage section, second storage section (sheet cassette) / 10a, 20a...contact section / 20L...locking mechanism / 204, 205, 206...locking member / 204a...contacted section / 50...image forming apparatus main body (printer unit) / 51...first housing (main body housing) / 200...sheet feeding device / 220...housing, first housing, second housing

Claims

1. A sheet feeding device that is used in a state connected to another unit and feeds sheets, the sheet feeding device having a first housing and a first storage section that stores sheets and is attached to the first housing so as to be removable, a second housing connected below the first housing; a second storage section that stores a seat and is attached to the second housing so as to be removable; a locking mechanism that can be in a locked state in which the first housing and the second housing are locked so as not to be separated, and an unlocked state in which the first housing and the second housing are allowed to be separated; and when the locking mechanism is in the locked state, the entire locking mechanism is located outside a movement locus of the first storage unit when the first storage unit is attached to and pulled out from the first housing, When the locking mechanism is in the unlocked state, the entire locking mechanism is configured not to be positioned outside the movement trajectory of the first storage section. A sheet feeding device characterized by:

2. the locking mechanism is a locking member having an engaging portion that engages with an engaged portion provided on the first housing, the engaging portion being movable so as to approach and move away from the engaged portion; When the engaging portion is disengaged from the engaged portion, at least a portion of the locking member is always positioned inside the movement locus of the first storage portion.

2. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.

3. When the locking mechanism is in the unlocked state, contact between the first storage unit and the locking member prevents the first storage unit from being pulled out or attached.

3. The sheet feeding device according to claim 2, wherein the sheet feeding device is a sheet feeding device.

4. the locking member has a contacted portion that comes into contact with the first storage portion when the first storage portion is moved while the locking mechanism is in the unlocked state, and is configured to rotate around a rotation axis; The contacted portion is disposed closer to the rotation axis than the engaging portion.

3. The sheet feeding device according to claim 2, wherein the sheet feeding device is a sheet feeding device.

5. The first storage section has a first contact portion that comes into contact with a part of the locking mechanism when the first storage section, when pulled out from the first housing, attempts to move in an attachment direction, and a second contact portion that is provided downstream of the first contact portion in the pull-out direction of the first storage section and comes into contact with a part of the locking mechanism when the first storage section, when mounted in the first housing, attempts to move in the pull-out direction.

2. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.

6. A sheet feeding device that is used in a state connected to another unit and feeds sheets, the sheet feeding device having a first housing and a first storage section that stores sheets and is attached to the first housing so as to be removable, a second housing connected below the first housing; a second storage section that stores a seat and is attached to the second housing so as to be removable; a locking mechanism that can be in a locked state in which the first housing and the second housing are locked so as not to be separated, and an unlocked state in which the first housing and the second housing are allowed to be separated, the locking mechanism is a locking member having an engaging portion that engages with an engaged portion provided on the first housing, the engaging portion being movable so as to approach and move away from the engaged portion; the locking member has a contacted portion that comes into contact with the first storage portion when the first storage portion is moved in a state where the locking member is in a position where the engaging portion is farthest from the engaged portion, A sheet feeding device characterized by:

7. When the locking mechanism is in the unlocked state, contact between the first storage unit and the locking member prevents the first storage unit from being pulled out or attached.

7. The sheet feeding device according to claim 6, wherein the sheet feeding device is a sheet feeding device.

8. The locking member is configured to rotate about a rotation axis; The contacted portion is disposed closer to the rotation axis than the engaging portion.

7. The sheet feeding device according to claim 6, wherein the sheet feeding device is a sheet feeding device.

9. The first storage section has a first contact portion that comes into contact with the locking member when the first storage section, when pulled out from the first housing, attempts to move in an attachment direction, and a second contact portion that is provided downstream of the first contact portion in the pull-out direction of the first storage section and comes into contact with the locking member when the first storage section, when mounted in the first housing, attempts to move in the pull-out direction.

7. The sheet feeding device according to claim 6, wherein the sheet feeding device is a sheet feeding device.

10. A sheet feeding device that is used in a state where it is connected to another unit having a first housing and feeds sheets, a second housing connected below the first housing; a storage section that stores a seat and is attached to the second housing so as to be removable; a locking mechanism that can be in a locked state in which the first housing and the second housing are locked so as not to be separated, and an unlocked state in which the first housing and the second housing are allowed to be separated; and when the locking mechanism is in the locked state, the entire locking mechanism is located outside a movement locus of the storage unit when the storage unit is attached to or pulled out from the first housing, When the locking mechanism is in the unlocked state, the entire locking mechanism is configured not to be positioned outside the movement trajectory of the storage unit. A sheet feeding device characterized by:

11. the locking mechanism is a locking member having an engaging portion that engages with an engaged portion provided on the first housing, the engaging portion being movable so as to approach and move away from the engaged portion; When the engaging portion is disengaged from the engaged portion, at least a portion of the locking member is always positioned inside the movement locus of the storage portion.

11. The sheet feeding device according to claim 10.

12. When the locking mechanism is in the unlocked state, contact between the storage unit and the locking member prevents the storage unit from being pulled out or attached.

12. The sheet feeding apparatus according to claim 11.

13. the locking member has a contacted portion that comes into contact with the storage portion when the storage portion is moved while the locking mechanism is in the unlocked state, and is configured to rotate around a rotation axis; The contacted portion is disposed closer to the rotation axis than the engaging portion.

12. The sheet feeding apparatus according to claim 11.

14. The storage unit has a first contact portion that comes into contact with a part of the locking mechanism when the storage unit, when pulled out from the second housing, attempts to move in an attachment direction, and a second contact portion that is provided downstream of the first contact portion in the pull-out direction of the storage unit and comes into contact with a part of the locking mechanism when the storage unit, when attached to the second housing, attempts to move in the pull-out direction.

11. The sheet feeding device according to claim 10.

15. the other unit is another sheet feeding device connected to an image forming apparatus main body that forms an image on a sheet and feeds a sheet toward the image forming apparatus main body; 15. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.

16. An image forming apparatus comprising the sheet feeding device according to any one of claims 1 to 14 and the other unit, the other unit is an image forming apparatus main body that forms an image on a sheet fed from the sheet feeding device; An image forming apparatus characterized by:

Images