JP2024126144A - SHEET FEEDING DEVICE AND IMAGE FORMING APPARATUS - Google Patents

Abstract

To enable a sheet jamming at positions of a pair of conveying rollers to be easily removed from a feeding tray, while separating the feeding tray with respect to a main body of an image forming device.SOLUTION: A sheet feeding device is provided with a connecting/separating mechanism 79 that makes a driven roller 61b separate with respect to a driving roller 61a in tandem with operation by which a feeding tray 12 is separated. The connecting/separating mechanism 79 is provided with a movable member 80 provided with a link part 81 that moves the driven roller 61b in a separating direction and a contacting part 83 that can contact a part 12a to be contacted of the feeding tray 12, which is further provided with a compressed spring 84 that energizes the movable member 80. The part 12a to be contacted of the feeding tray 12, to which the feeding tray 12 is attached, contacts the contacting part 83 of the movable member 80 to restrict the link part 81 of the movable member 80 from moving in a predetermined direction against the energization of the compressed spring 84.SELECTED DRAWING: Figure 4

Description

This invention relates to a sheet feeding device that feeds sheets, and an image forming device equipped with the same, such as a copier, printer, facsimile, or a multifunction machine or printing machine that is one of these.

Conventionally, in image forming devices such as copiers, printers, and printing machines, it has been widely known that a feed tray (paper feed cassette) containing sheets such as paper is installed in a detachable (removable) manner relative to the main body of the image forming device (see, for example, Patent Document 1).
The sheet fed from the feed tray is then transported further downstream in the transport direction by a pair of transport rollers disposed in the vicinity of the sheet on the downstream side in the transport direction.

On the other hand, Patent Document 1 discloses a technology for improving the ease of removing (jam removal) a sheet that has jammed at the position of the transport roller pair, in which when an exterior cover installed near the transport roller pair is opened, one of the two rollers that make up the transport roller pair is moved away from the other roller in conjunction with the opening action.

In conventional image forming devices, if a sheet jams at the position of the pair of transport rollers installed near the downstream side of the feed tray, it is not possible to easily remove (clear the jam) the sheet from the feed tray side when the feed tray is detached (pulled out) from the image forming device main body.

This invention was made to solve the above-mentioned problems, and aims to provide a sheet feeding device and an image forming device that can easily remove a sheet that has jammed at the position of a pair of transport rollers installed near the downstream side of the feed tray from the feed tray side when the feed tray is detached from the image forming device main body.

The sheet feeding device of the present invention comprises a feed tray that is detachably installed in the image forming device body and capable of storing sheets, a pair of transport rollers that are installed on the side of the image forming device body and transport the sheets fed from the feed tray when the feed tray is attached to the image forming device body, and a contact/separation mechanism that separates one roller of the pair of transport rollers from the other roller in conjunction with the operation of removing the feed tray from the image forming device body, and the contact/separation mechanism separates the one roller of the pair of transport rollers from the other roller in conjunction with the operation of removing the feed tray from the image forming device body. The roller is provided with a link section that moves in a predetermined direction in conjunction with the link section to move the other roller in the separation direction, a contact section that can contact the contacted section of the feed tray, a movable member, and a biasing member that biases the movable member so that the link section moves in the predetermined direction, and the contacted section of the feed tray contacts the contacted section of the movable member when the feed tray is attached to the image forming device body, and limits the movement of the link section of the movable member in the predetermined direction against the bias of the biasing member.

The present invention provides a sheet feeding device and an image forming device that can easily remove a sheet that has jammed at the position of a pair of transport rollers installed near the downstream side of the feed tray from the feed tray side while the feed tray is detached from the image forming device main body.

1 is an overall configuration diagram showing an image forming apparatus according to an embodiment of the present invention; FIG. 2 is a configuration diagram showing a part of a sheet feeding device. 11A and 11B are diagrams illustrating a procedure for removing a jam by pulling out the first tray from the image forming apparatus main body. 4A and 4B are diagrams illustrating a contact/separation mechanism and a feeding tray. FIG. 2 is a diagram showing a pair of conveying rollers, a drive mechanism, and a contact/separation mechanism in the axial direction. FIG. FIG. 13A and 13B are diagrams illustrating a contact/separation mechanism and a feeding tray according to a first modified example. 13 is a diagram showing a contact/separation mechanism and a feeding tray according to a second modified example. FIG.

The following describes in detail the embodiments of the present invention with reference to the drawings. Note that in each drawing, the same or corresponding parts are given the same reference numerals, and the repeated explanations will be appropriately simplified or omitted.

First, the overall configuration and operation of an image forming apparatus 1 will be described with reference to FIG.
In FIG. 1, reference numeral 1 denotes a printer as an image forming apparatus, 2 denotes a photosensitive drum, 3 denotes a charging device that charges the surface of the photosensitive drum 2, and 6 denotes an exposure device that irradiates the surface of the photosensitive drum 2 charged by the charging device 3 with laser light L to form an electrostatic latent image.
Reference numeral 4 denotes a developing device that develops the electrostatic latent image formed on the surface of the photosensitive drum 2 to form a toner image, and reference numeral 7 denotes a transfer device that transfers the toner image formed on the surface of the photosensitive drum 2 onto a sheet P. Reference numeral 5 denotes a cleaning device that cleans the surface of the photosensitive drum 2 to remove untransferred toner.
Reference numeral 11 denotes a sheet feeding device provided with three stages of first to third feeding trays 12 to 14, and reference numeral 51 denotes a feeding mechanism for feeding the sheets P stored in the first to third feeding trays. Reference numerals 61 to 63 denote first to third conveying roller pairs provided on the first to third conveying paths K1 to K3.
In addition, reference numeral 17 denotes a pair of registration rollers (a pair of timing rollers) that transport the sheet P toward the position of the transfer device 7, reference numeral 20 denotes a fixing device that fixes the toner image (unfixed image) carried on the sheet P, and reference numeral 31 denotes a stack section on which the sheet P discharged from the image forming apparatus main body 1 is stacked.
In the image forming apparatus 1 configured as above, the side from which the first to third feed trays 12 to 14 are pulled out (the left side in FIGS. 1 and 3) is the side operated by an operator and corresponds to the front side of the image forming apparatus 1. In contrast, the side on which the first to third transport paths K1 to K3 (the first to third transport roller pairs 61 to 63) are provided (the right side in FIGS. 1 and 3) corresponds to the rear side of the image forming apparatus 1 (the side that is likely to face the wall of a room).

The operation of the image forming apparatus 1 during normal image formation (printing) will be described with reference to FIG.
First, when image information is input to the exposure device 6 from a personal computer (not shown) or the like connected to the image forming apparatus 1, the exposure device 6 emits laser light L based on the image information toward the photosensitive drum 2.

Meanwhile, the photosensitive drum 2 rotates counterclockwise in FIG. 1, and through a predetermined image creation process (charging process, exposure process, and development process), an image (toner image) corresponding to the image information is formed on the photosensitive drum 2.
Thereafter, the image formed on the photosensitive drum 2 is transferred onto the sheet P conveyed by a pair of registration rollers 17 at the position of the transfer device 7 (image forming portion).

On the other hand, the sheet P conveyed to the position of the transfer device 7 (image forming portion) operates as follows.
First, one of the first to third feed trays 12 to 14 arranged side by side below the image forming apparatus 1 is automatically or manually selected (for example, the bottom third feed tray 14 is selected). Then, the topmost sheet of the sheets P stored in the third feed tray 14 is fed by the feeding mechanism 51 and conveyed in this order through the third conveying path K3 on which the third conveying roller pair 63 is installed, the second conveying path K2 on which the second conveying roller pair 62 is installed, and the first conveying path K1 on which the first conveying roller pair 61 is installed.
Thereafter, the sheet P reaches the position of the registration roller pair 17. At this time, the registration roller pair 17 is in a state of stopping rotation, and the leading edge of the sheet P abuts against the nip of the registration roller pair 17, so that the skew of the sheet P is corrected.

Then, the pair of registration rollers 17 start to rotate, and the sheet P is transported toward the transfer device 7 (image forming section) in time for alignment with the image formed on the photosensitive drum 2. Then, the image on the photosensitive drum 2 is transferred onto the sheet P by the transfer device 7 (transfer process).
After the transfer process, the sheet P passes through the transfer device 7, and then travels through a transport path to the fixing device 20. The sheet P that has reached the fixing device 20 is fed between a fixing roller and a pressure roller, and the toner image is fixed by the heat from the fixing roller and the pressure at the nip (fixing process). The sheet P after the fixing process with the toner image fixed is sent out from the fixing device 20, and then discharged from the image forming apparatus 1, and placed on the stack unit 31 as an output image.
In this way, a series of image forming processes (printing operations) is completed.

Next, the feeding mechanism 51 in the sheet feeding device according to the present embodiment will be described in detail with reference to FIG.
In the following, we will explain the feeding mechanism 51 that feeds sheets P stored in the second feeding tray 13 in the middle level among the first to third feeding trays 12 to 14. However, since the feeding mechanisms that feed sheets P stored in the other feeding trays 12 and 14 have almost the same configuration, we will not repeat the explanation.

Referring to Figure 2, the feed tray 13 is provided with a loading section 43 formed so as to be able to stack multiple sheets P (sheet stack PT), a feeding mechanism 51 for feeding the sheets P loaded on the loading section 43, and the like.
The placement section 43 is configured such that a portion thereof can be raised and lowered so that the downstream side in the feeding direction (the right side in FIG. 2) of the uppermost sheet P of the stacked sheet bundle PT reaches a predetermined height position (the position of the pickup roller 52). Specifically, the placement section 43 is configured to have a lifting plate that can rotate about a rotation center shaft 43a and a fixed plate that does not rise and fall. The lifting plate is disposed downstream in the feeding direction from the fixed plate, and is configured to be raised and lowered by rotating in forward and reverse directions about the rotation center shaft 43a.
2, the feeding mechanism 51 is made up of a feed roller 53, a pick-up roller 52, a separation roller 54, and the like.

The feed roller 53 is installed on the leading edge (downstream side) of the sheet P placed on the loading section 43 in the feeding direction (the direction of the white arrow in Figure 2), and contacts the top surface of the uppermost sheet P and rotates along the feeding direction of the sheet P (counterclockwise rotation in Figure 2) to feed the sheet P in the feeding direction indicated by the dotted dashed arrow.
2 along the running direction while in contact with the surface (top surface) of the uppermost sheet P placed on the placement section 43, and conveys the sheet P toward the position of the feed roller 53. The pickup roller 52 is configured to be capable of contacting and separating from the sheet P (uppermost sheet P) placed on the placement section 43 (lifting plate). That is, the pickup roller 52 is formed to be movable between a retracted position where it does not contact the sheet P placed on the placement section 43 and a contact position (the position shown in FIG. 2) where it contacts the sheet P.
The separation roller 54 is disposed so as to form a nip portion between itself and the feed roller 53 .
The separation roller 54 rotates in the forward direction (the direction of the dashed arrow in FIG. 2, which is the clockwise direction) along the feeding direction when one sheet P is sandwiched in the nip portion and when no sheet P is sandwiched in the nip portion. In contrast, the separation roller 54 rotates in the reverse direction (the direction of the solid arrow in FIG. 2, which is the counterclockwise direction) to the forward direction described above when multiple sheets are sandwiched in the nip portion. As a result, the uppermost sheet P of the multiple sheets P sandwiched in the nip portion is fed in the feeding direction along with the rotation of the feed roller 53, and the lower sheet P is transported in the reverse direction to the feeding direction (forward direction), thereby reducing double feeding and continuous feeding of the sheets P.
In this embodiment, the separation roller 54 may be replaced with a plate-shaped separation pad.

Here, in the feeding tray 13, the loading section 43 (lifting plate) is raised and lowered in the vertical direction depending on the number of sheets P stacked on the loading section 43 so that the pickup roller 52 can abut against the uppermost sheet P of the sheet stack PT stacked on the loading section 43 (lifting plate). Then, the pickup roller 52 descends to a position where it abuts against the upper surface of the sheet P placed on the loading section 43 (lifting plate) whose vertical position has been adjusted, and then the sheet P is fed.
Further, the feeding tray 13 in this embodiment is provided with a pair of side fences (not shown) that regulate the position in the width direction (the direction perpendicular to the plane of the paper in FIG. 2) of the sheet P placed on the placement portion 43. The side fences are respectively installed at both ends in the width direction so as to sandwich the sheet P, and are configured to be movable in conjunction with each other in the width direction by a manual movement mechanism in accordance with the width size of the sheet P (configured so that the distance in the width direction can be increased or decreased).
Further, the feeding tray 13 in this embodiment is provided with a reference fence 107 and an end fence 103 that regulate the position of the sheet P placed on the placement portion 43 in the feeding direction (the left-right direction in FIG. 2). The reference fence 107 is installed so that the side surface (leading end) of the sheet P on the downstream side in the feeding direction abuts against the reference fence 107. The end fence 103 is installed so as to abut against the side surface (rear end) of the sheet P on the upstream side in the feeding direction, and is configured to be movable in the feeding direction in accordance with the size of the sheet P in the feeding direction by a manual movement mechanism.

Hereinafter, the sheet feeding device 11 (image forming apparatus 1), which is a characteristic feature of this embodiment, will be described with reference to FIGS.
1, 3, etc., in the sheet feeding device 11 in this embodiment, three (three tiers) feeding trays 12 to 14 (trays) capable of storing sheets P are arranged in a vertical direction. Each of the feeding trays 12 to 14 is installed in a detachable manner (removable) with respect to the image forming apparatus main body 1.
A feeding mechanism 51 is provided above the downstream side of each of the feeding trays 12 to 14 in the feeding direction, and pairs of conveying rollers 61 to 63 (conveying paths K1 to K3) are provided further downstream in the feeding direction.
In this specification and the like, the state in which the "detachable" feed trays 12-14 are "detached" from the image forming apparatus main body 1 is defined to include not only a state in which the feed trays 12-14 are completely removed from the image forming apparatus main body 1 (such as the state of the first feed tray 12 in Figure 3(C)), but also a state in which a portion of the feed trays 12-14 is held by the image forming apparatus main body 1 and pulled out (such as the state of the first feed tray 12 in Figure 3(B)).

3A and the like, a first conveying roller pair 61 is disposed in the conveying path of the sheet P fed from the first feeding tray 12. Specifically, when the sheet P is fed from the first feeding tray 12, the sheet P passes through the first conveying path K1 (the first conveying roller pair 61).
On the other hand, when the sheet P is fed from the second feeding tray 13, the sheet P passes through the second transport path K2 (the second transport roller pair 62) and the first transport path K1 (the first transport roller pair 61).
In addition, when a sheet P is fed from the third feeding tray 14, the sheet P passes through the third transport path K3 (third transport roller pair 63), the second transport path K2 (second transport roller pair 62), and the first transport path K1 (first transport roller pair 61).

Of the three feed trays 12-14 and the three transport roller pairs 61-63, the following describes the first upper feed tray 12 and the first transport roller pair 61 of the first transport path K1. However, the other feed trays 13, 14 and transport roller pairs 62, 63 have almost the same configuration, so their description will be omitted.

3 to 7, the sheet feeding device 11 in the present embodiment is provided with a first feeding tray 12 as a feeding tray, and a first conveying roller pair 61 as a conveying roller pair.
The first feeding tray 12 is detachably installed in the image forming apparatus main body 1, and functions as a feeding tray capable of storing a sheet P (or a plurality of sheets P).
The first conveying roller pair 61 is installed on the side of the image forming apparatus main body 1 so as not to be attached or detached in conjunction with the attachment or detachment operation of the first feeding tray 12 (feeding tray), and functions as a conveying roller pair that conveys the sheet P fed from the first feeding tray 12 (feeding tray) in a state where it is attached to the image forming apparatus main body 1. This first conveying roller pair 61 (conveying roller pair) is composed of a driving roller 61a as one roller and a driven roller 61b as the other roller. A nip is formed between the two rollers 61a and 61b, and each of them rotates along the conveying direction to sandwich and convey the sheet P. The driving roller 61a as one roller is rotated by a driving mechanism 90 (see FIG. 4 and FIG. 6). The driven roller 61b as the other roller abuts against the driving roller 61a and rotates in conjunction with the rotation of the driving roller 61a.

The first conveying roller pair 61 (or the second and third conveying roller pairs 62 and 63) as the conveying roller pair is provided downstream (on the right side in Figs. 1, 3 and 5) in the mounting direction of the first feeding tray 12 (or the second and third feeding trays 13 and 14) as the feeding tray. The image forming device main body 1 is installed so that the upstream side in the mounting direction (on the left side in Figs. 1, 3 and 5) is the front and the downstream side in the mounting direction (on the right side in Figs. 1, 3 and 5) is the back. Therefore, assuming that the back of the image forming device 1 is installed facing the wall of a room, it is preferable to configure the sheet P jammed at the positions of the first to third conveying roller pairs 61 to 63 so that it can be removed from the other side (particularly the front side, which is the operating side for the operator) rather than by opening the exterior cover from the back side.

Now, referring to Figure 4 (and Figure 3), the sheet feeding device 11 in this embodiment is provided with a contact/separation mechanism 79 that contacts and separates the drive roller 61a (one roller) and the driven roller 61b (the other roller) of the first conveying roller pair 61 as a conveying roller pair.
The contact/separation mechanism 79 is configured to separate the driven roller 61b from the drive roller 61a in conjunction with the operation of removing (pulling out) the first feed tray 12 (feed tray) from the image forming apparatus main body 1.
Specifically, as shown in Figures 3 (A) and 4 (A), when the first feeding tray 12 is attached to the image forming apparatus main body 1, as during normal printing, the drive roller 61a and the driven roller 61b are in contact with each other, making it possible for the sheet P to be transported by the first transport roller pair 61.
3B and 4B, when printing is stopped (driving of the image forming apparatus 1 (driving roller 61a) is stopped) and the first feeding tray 12 is pulled out from the image forming apparatus main body 1, the driven roller 61b is separated from the driving roller 61a by the contact/separation mechanism 79. By separating the driving roller 61a and the driven roller 61b in this manner, even if a sheet P is jammed at the position of the first conveying roller pair 61 as shown in FIG. 3B, it is possible to insert a hand into the space of the pulled out first feeding tray 12 and easily take out (remove) the jammed sheet P in the direction of the black arrow in FIG. 3C.
3C, when an operator clears a jam by pulling the sheet P in the direction of the black arrow, the first conveying roller pair 61 is in a separated state, but the feed roller 53 and separation roller 54 of the feeding mechanism 51 (see FIGS. 1 and 2) are in contact with each other. However, as described above, the separation roller 54 is configured to be able to rotate in the reverse direction relative to the feeding direction, so it does not become a large load resistance when an operator clears a jam by pulling the sheet P in the direction of the black arrow.

In this way, in the sheet feeding device 11 of the present embodiment, when the first feeding tray 12 (feeding tray) is detached, the first conveying roller pair 61 (conveying roller pair) is switched from a contact state to a separated state, so that a sheet P that has jammed at the position (nip) of the first conveying roller pair 61 can be easily removed (jam clearance) from the side of the first feeding tray 12 with the first feeding tray 12 detached from the image forming apparatus main body 1.
In addition, the contact/separation mechanism 79 is configured so that the driven roller 61b abuts against the drive roller 61a in conjunction with the operation of attaching (pushing in) the first feed tray 12 (feed tray), which was detached from the image forming apparatus main body 1.

As shown in FIG. 6, a drive gear 61x is installed on one end of the rotation shaft of the drive roller 61a. This drive gear 61x meshes with a motor gear 92 installed on the motor shaft of the drive motor 91, and the drive of the motor 91 is transmitted. As a result, the drive roller 61a is driven to rotate in a predetermined direction (counterclockwise in FIG. 4) by the drive motor 91 controlled by the control unit. In this way, the drive motor 91, motor gear 92, etc. function as a drive mechanism 90 that drives and rotates the drive roller 61a.

The configuration and operation of the contact/separation mechanism 79 will be described in detail below with reference to FIGS.
3 and the like, the contact/separation mechanism 79 separates the driven roller 61b (the other roller) from the drive roller 61a (one roller) of the first conveying roller pair 61 (conveying roller pair) in conjunction with the operation of removing the first feeding tray 12 (feeding tray) from the image forming apparatus main body 1. In detail, the contact/separation mechanism 79 contacts and separates the first conveying roller pair 61 in conjunction with the attachment/detachment operation of the first feeding tray 12.
4, 6, etc., in this embodiment, the contact/separation mechanism 79 is made up of a movable member 80 (movable plate), a compression spring 84 as a biasing member, and the like.

4 and 6, the movable member 80 is provided at each of both axial ends (both widthwise ends) of the sheet feeding device 11. The movable member 80 is provided with a link portion 81. The movable member 80 is held by a housing formed in the sheet feeding device 11 so as to be movable in the up and down direction.
On the other hand, the driven roller 61b has a rotation shaft at both ends thereof rotatably held by a holder 70. Also, a fitting portion 70a that protrudes axially outward is formed on each of both axial ends of the holder 70. The holder 70 (driven roller 61b) is held by a housing of the sheet feeding device 11 so as to be movable in a substantially horizontal direction.

The link portion 81 of the movable member 80 is an irregularly shaped opening formed in the plate-shaped movable member 80, and moves in a predetermined direction (the direction of the arrow in FIG. 4(B), downward) in conjunction with the action of removing (pulling out) the first feed tray 12 (feed tray), thereby moving the driven roller 61b in the separation direction (the direction of the black arrow in FIG. 4(B), to the right).

Specifically, with reference to FIG. 5, the link portion 81 is provided with a first opening 81a, a second opening 81b, and a third opening 81c.
The first opening 81a is formed on the downstream side (lowest part) in the predetermined direction so as to extend in a rectangular shape in the predetermined direction (up-down direction).
The second opening 81b is formed upstream (upward) in a predetermined direction than the first opening 81a, and is formed so as to extend in a rectangular shape in a predetermined direction (up and down direction) at a position farther from the drive roller 61a (one of the rollers) than the first opening 81a.
The third opening 81c connects the first opening 81a and the second opening 81b. The third opening 81c is formed to extend obliquely from the bottom to the top while maintaining a constant width (the longitudinal width of the fitting portion 70a + α).
The link portion 81 is fitted with a fitting portion 70a of a holder 70 which rotatably holds the driven roller 61b.

With this configuration, when the movable member 80 descends from the position shown in Fig. 4(A) to the position shown in Fig. 4(B), the fitting portion 70a moves to the right along the shape of the link portion 81, and the driven roller 61b also moves to the right accordingly. As a result, the driven roller 61b moves away from the drive roller 61a.
4(A) from the position shown in Fig. 4(B), the engaging portion 70a moves leftward to follow the shape of the link portion 81, and the driven roller 61b also moves leftward accordingly. As a result, the driven roller 61b comes into contact with the driving roller 61a.

Also, referring to FIG. 4, a compression spring 84 (biasing member) of the contact/separation mechanism 79 biases the movable member 80 so that the link portion 81 moves in a predetermined direction (downward in FIG. 4).
Specifically, one end (upper end) of the compression spring 84 is connected to the housing 11 x of the sheet feeding device 11 , and the other end (lower end) is connected to the lower end of the opening of the movable member 80 .
In addition, the biasing force of this compression spring 84 is useful when the movable member 80 is lowered (when the driven roller 61b is separated) when the movable member 80 does not descend smoothly due to the sliding resistance between the link portion 81 and the engaging portion 70a, caused by the weight of the movable member 80 alone.

As shown in FIG. 4A, the movable member 80 is formed with a contact portion 83 that can come into contact with the contacted portion 12a of the first feeding tray 12 (feeding tray).
The abutting portion 12a of the first feed tray 12 (feed tray) abuts against the abutting portion 83 of the movable member 80 when the first feed tray 12 is attached to the image forming apparatus main body 1, and limits the movement of the movable member 80 against the force of the compression spring 84 (biasing member) so that the link portion 81 does not move in a specified direction (downward).
That is, when the contacted portion 12a of the first feeding tray 12 contacts the contact portion 83 of the movable member 80, the movable member 80 is pushed upward against the spring force of the compression spring 84. Then, as shown in Fig. 4B, when the first feeding tray 12 is pulled out, the contact between the contacted portion 12a and the contact portion 83 is released, and the movable member 80 descends due to the spring force of the compression spring 84 and the weight of the movable member 80, and the driven roller 61b is separated. On the other hand, when the first feeding tray 12 in the pulled out state shown in Fig. 4B is pushed into the image forming apparatus main body 1 as shown in Fig. 4A, the contacted portion 12a contacts and pushes up the contact portion 83, and the movable member 80 is pushed upward against the spring force of the compression spring 84.

Here, in order to smoothly bring the abutted portion 12a into contact with and release the abutment from the abutting portion 83, the opposing surfaces facing the other side are formed so as to be inclined with respect to the attachment/detachment direction.
Specifically, the abutment portion 12a is provided at the end portion downstream of the mounting direction of the first feed tray 12 (the right side in Figures 4 and 7), and has an inclined surface that slopes from above to below toward the movable member 80.
In addition, the abutment portion 83 is provided on the lower part of the movable member 80, on the side facing the first feed tray 12 (the left side in Figure 4), and an inclined surface that slopes from the bottom to the top toward the first feed tray 12 is formed.
4B, the lowered position of the movable member 80 can be determined by the upper end position of the second opening 81b of the link portion 81, or by providing a locking portion on the housing of the sheet feeding device 11. The lowered position is determined so that the inclined surface of the abutted portion 12a and the inclined surface of the abutting portion 83 always come into contact with each other in conjunction with the operation of the first feeding tray 12 moving horizontally to be attached.

As described above with reference to Fig. 6 and the like, the contact/separation mechanism 79 (contact portion 83) is provided at both ends in the axial direction, and correspondingly, the contacted portion 12a of the first feeding tray 12 (feeding tray) is also provided at both ends in the axial direction, as shown in Fig. 7.
In this way, by providing the contact/separation mechanism 79 (contact portion 83) and the contacted portion 12a of the first feeding tray 12 at both axial ends, respectively, the contact/separation operation of the first conveying roller pair 61 can be performed smoothly and in a well-balanced manner.

<Modification 1>
As shown in Figure 8, in the contact/separation mechanism 79 in the modified example 1, the link portion 81 of the movable member 80 is provided with a stopper portion 81x that limits the movement in a predetermined direction (downward) of the fitting portion 70a (formed in the holder 70 that holds the driven roller 61b) in the first opening 81a (see Figure 5).
That is, as shown in FIG. 8, when the abutted portion 12a of the first feeding tray 12 abuts against the abutment portion 83 of the movable member 80, the movable member 80 is pushed upward to a position where the driven roller 61b abuts against the drive roller 61a, but even if the movable member 80 attempts to rise to a position higher than that, the engaging portion 70a comes into contact with the stopper portion 81x, and the upward movement is restricted.
This prevents a problem that occurs when the driven roller 61b does not come into contact with the drive roller 61a and the first conveyor roller pair 61 does not function.

<Modification 2>
As shown in FIG. 9, in the second modified example, the contacted portion 12a of the first feeding tray 12 (feeding tray) has a roller 12a1 that contacts the contact portion 83 of the movable member 80 and is rotatably supported by a shaft.
This reduces the sliding resistance that occurs when the contacted portion 12a and the contact portion 83 contact or release each other, and thus the attachment and detachment operation of the first feeding tray 12 and the associated contact and detachment operation of the contact/detachment mechanism 79 can be performed smoothly.
In the second modification, a fourth opening 81m is formed in the link portion 81 of the movable member 80 downstream (lower) in a predetermined direction from the first opening 81a (see FIG. 5). The fourth opening 81m is formed to extend in a rectangular shape in a predetermined direction (up-down direction) at a position close to the first opening 81a with respect to the driving roller 61a (one of the rollers). In addition, an opening (fifth opening) that connects the first opening 81a and the fourth opening 81m is also formed. The fifth opening is formed to extend obliquely from the bottom to the top while maintaining a constant width (the longitudinal width of the fitting portion 70a + α).
This fourth opening 81m is used when the surface layer (made of rubber material, resin material, etc.) of the driving roller 61a or the driven roller 61b wears over time and the nip can no longer be formed (when a gap occurs between the rollers). Specifically, initially, the fitting portion 70a is fitted into the first opening 81a when the first conveying roller pair 61 contacts, and the fitting portion 70a is fitted into the second opening 81b when the first conveying roller pair 61 separates. However, over time (when worn and deteriorated), the fitting portion 70a is fitted into the fourth opening 81m when the first conveying roller pair 61 contacts, and the fitting portion 70a is fitted into the first opening 81a when the first conveying roller pair 61 separates.
At this time, as time passes (due to wear and deterioration), it is necessary to raise the position of the movable member 80 (contact portion 83) when pushed up by the first feeding tray 12 (contact portion 12a) compared to the initial state. Therefore, as time passes (due to wear and deterioration), the rollers 12a1' are replaced with rollers 12a1' having a larger outer diameter, or a plate-like member of an appropriate thickness is attached to the inclined surface of the contact portion 83, as shown in FIG.

As described above, the sheet feeding device 11 in this embodiment is provided with a first feeding tray 12 (feeding tray) that is detachably installed in the image forming apparatus main body 1 and can store sheets P. Also, a first conveying roller pair 61 (conveying roller pair) that conveys the sheets P fed from the first feeding tray 12 in a state where it is attached to the image forming apparatus main body 1 is installed on the side of the image forming apparatus main body 1. Furthermore, a contact/separation mechanism 79 is provided that separates the driven roller 61b (the other roller) of the first conveying roller pair 61 from the driving roller 61a (one roller) in conjunction with an operation of removing the first feeding tray 12 from the image forming apparatus main body 1. The contact/separation mechanism 79 is provided with a movable member 80 including a link portion 81 that moves in a predetermined direction in conjunction with the operation of separating the first feeding tray 12 to move the driven roller 61b in the separation direction, and an abutting portion 83 that can abut against the abutted portion 12a of the first feeding tray 12, and further includes a compression spring 84 (biasing member) that urges the movable member 80 so that the link portion 81 moves in the predetermined direction. The abutted portion 12a of the first feeding tray 12 abuts against the abutting portion 83 of the movable member 80 when the first feeding tray 12 is attached to the image forming apparatus main body 1, and limits the movement of the link portion 81 of the movable member 80 in the predetermined direction against the urging of the compression spring 84.
This allows a sheet P that has jammed at the position of the first conveying roller pair 61 (conveying roller pair) installed near the downstream side of the first feeding tray 12 (feeding tray) to be easily removed from the side of the first feeding tray 12 while the first feeding tray 12 is detached from the image forming device main body 1.

In this embodiment, the present invention is applied to a sheet feeding device 11 installed in a monochrome image forming apparatus 1, but the present invention can naturally also be applied to a sheet feeding device installed in a color image forming apparatus.
Furthermore, in this embodiment, the present invention is applied to a sheet feeding device 11 installed in an electrophotographic image forming apparatus 1, but the application of the present invention is not limited to this, and the present invention can also be applied to sheet feeding devices installed in other types of image forming apparatuses (e.g., inkjet image forming apparatuses, stencil printers, etc.).
In the present embodiment, the first to third feed trays 12 to 14 are installed in the three stages in the image forming apparatus 1, but one or two stages, or even four or more stages of feed trays (including a manual feed tray exposed to the outside of the image forming apparatus) may also be installed in the image forming apparatus. As described in the embodiment, the present invention may be applied to a single stage of feed trays or each stage of multiple feed trays.
In addition, in this embodiment, the present invention is applied to a sheet feeding device 11 provided with a feeding mechanism 51 consisting of a pickup roller 52, a feed roller 53, and a separation roller 54, but the present invention can naturally be applied to sheet feeding devices provided with feeding mechanisms of other types.
Even in such cases, the same effects as those of this embodiment can be obtained.

It is clear that the present invention is not limited to this embodiment, and that within the scope of the technical concept of the present invention, this embodiment may be modified as appropriate in ways other than those suggested in this embodiment. Furthermore, the number, position, shape, etc. of the components are not limited to this embodiment, and may be any number, position, shape, etc. that is suitable for implementing the present invention.

In this specification, the term "sheet" is defined to include not only paper, but also all sheet-like recording media such as coated paper, label paper, overhead projector sheets, and film sheets.

1 Image forming device (image forming device main body),
11 sheet feeding device,
12 first feed tray (feed tray),
12a contact portion,
12a1 roller (rotating body),
13 second feed tray (feed tray),
14 Third feed tray (feed tray),
61 first conveying roller pair (conveying roller pair),
61a driving roller (one of the rollers);
61b driven roller (the other roller);
70 Holder,
70a fitting portion,
79 Contact mechanism,
80 Movable member,
81 link section,
81a first opening, 81b second opening, 81c third opening,
81m 4th opening,
81x stopper part,
83 abutment portion,
84 compression spring (biasing member),
90 Drive mechanism,
K1: first transport path; K2: second transport path; K3: third transport path;
P seat.

In addition, the aspect of the present invention can also be a combination of Supplementary Notes 1 to 10 as follows.
(Appendix 1)
a feed tray that is detachably installed in a main body of the image forming apparatus and is capable of storing sheets;
a pair of conveying rollers that are installed on the side of the image forming apparatus main body and convey a sheet fed from the feed tray in a state where the image forming apparatus main body is attached;
a separation mechanism for separating one roller of the pair of conveying rollers from the other roller in association with an operation of removing the feed tray from the image forming apparatus body;
Equipped with
The contact/separation mechanism includes:
a movable member including a link portion that moves in a predetermined direction in conjunction with an operation of removing the feed tray to move the other roller in a separating direction, and an abutting portion that can abut against a contacted portion of the feed tray;
a biasing member that biases the movable member so that the link portion moves in the predetermined direction;
Equipped with
A sheet feeding device characterized in that the abutment portion of the feeding tray abuts against the abutment portion of the movable member when the feeding tray is attached to the image forming device main body, thereby limiting the movement of the link portion of the movable member in the specified direction against the force of the biasing member.
(Appendix 2)
a holder for holding the other roller and having a fitting portion formed to fit with the link portion,
The link portion is
A first opening extending in a rectangular shape in the predetermined direction;
a second opening formed upstream of the first opening in the predetermined direction and extending in a rectangular shape in the predetermined direction at a position farther from the one roller than the first opening;
a third opening connecting the first opening and the second opening;
2. The sheet feeding device according to claim 1, comprising:
(Appendix 3)
The sheet feeding device described in Appendix 2, characterized in that the link portion is formed downstream of the first opening in the specified direction and has a fourth opening extending in a rectangular shape in the specified direction at a position closer to the first opening relative to one of the rollers.
(Appendix 4)
The sheet feeding device according to claim 2 or 3, wherein the link portion includes a stopper portion that limits movement of the fitting portion in the first opening in the predetermined direction.
(Appendix 5)
The sheet feeding device according to any one of claims 1 to 4, wherein the contact/separation mechanism and the fitted portion of the feeding tray are provided at both ends in the axial direction, respectively.
(Appendix 6)
A sheet feeding device described in any one of Appendix 1 to Appendix 5, characterized in that the contact portion and the contacted portion each have opposing surfaces that face each other and are inclined with respect to the attachment and detachment direction of the feeding tray.
(Appendix 7)
7. The sheet feeding device according to claim 1, wherein the contacted portion includes a roller that contacts the contact portion.
(Appendix 8)
The conveying roller pair includes:
A drive roller that is rotationally driven by a drive mechanism;
a driven roller that is in contact with the drive roller and rotates in conjunction with the rotation of the drive roller;
Equipped with
The one roller is the drive roller,
The sheet feeding device according to any one of claims 1 to 7, wherein the other roller is the driven roller.
(Appendix 9)
9. An image forming apparatus comprising the sheet feeding device according to claim 1.
(Appendix 10)
the pair of conveying rollers is provided downstream in a mounting direction of the feed tray,
10. The image forming apparatus according to claim 9, wherein the image forming apparatus main body is installed so that the upstream side in the mounting direction is the front side and the downstream side in the mounting direction is the back side.

Japanese Patent Application Publication No. 10-147451

Claims (10)

a feed tray that is detachably installed in a main body of the image forming apparatus and is capable of storing sheets;
a pair of conveying rollers that are installed on the side of the image forming apparatus main body and convey a sheet fed from the feed tray in a state where the image forming apparatus main body is attached;
a separation mechanism for separating one roller of the pair of conveying rollers from the other roller in association with an operation of removing the feed tray from the image forming apparatus body;
Equipped with
The contact/separation mechanism includes:
a movable member including a link portion that moves in a predetermined direction in conjunction with an operation of removing the feed tray to move the other roller in a separating direction, and an abutting portion that can abut against a contacted portion of the feed tray;
a biasing member that biases the movable member so that the link portion moves in the predetermined direction;
Equipped with
A sheet feeding device characterized in that the abutment portion of the feeding tray abuts against the abutment portion of the movable member when the feeding tray is attached to the image forming device main body, thereby limiting the movement of the link portion of the movable member in the specified direction against the force of the biasing member. a holder for holding the other roller and having a fitting portion formed to fit with the link portion,
The link portion is
A first opening extending in a rectangular shape in the predetermined direction;
a second opening formed upstream of the first opening in the predetermined direction and extending in a rectangular shape in the predetermined direction at a position farther from the one roller than the first opening;
a third opening connecting the first opening and the second opening;
2. The sheet feeding apparatus according to claim 1, further comprising: The sheet feeding device according to claim 2, characterized in that the link portion is formed downstream of the first opening in the predetermined direction and has a fourth opening that extends in a rectangular shape in the predetermined direction at a position closer to the first opening relative to the one roller. The sheet feeding device according to claim 2, characterized in that the link portion has a stopper portion that limits the movement of the engagement portion in the first opening in the predetermined direction. The sheet feeding device according to claim 1 or 2, characterized in that the contact/separation mechanism and the mating portion of the feeding tray are provided at both axial ends, respectively. The sheet feeding device according to claim 1 or 2, characterized in that the contacting portion and the contacted portion each have an opposing surface that is inclined with respect to the attachment/detachment direction of the feeding tray. The sheet feeding device according to claim 1 or 2, characterized in that the abutted portion is provided with a roller that abuts against the abutting portion. The conveying roller pair includes:
A drive roller that is rotationally driven by a drive mechanism;
a driven roller that is in contact with the drive roller and rotates in conjunction with the rotation of the drive roller;
Equipped with
The one roller is the drive roller,
3. The sheet feeding device according to claim 1, wherein the other roller is the driven roller. An image forming apparatus comprising the sheet feeding device according to claim 1 or 2. the pair of conveying rollers is provided downstream in a mounting direction of the feed tray,
10. The image forming apparatus according to claim 9, wherein the image forming apparatus body is installed such that the upstream side in the mounting direction is a front side and the downstream side in the mounting direction is a rear side.

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