SHEET STOP MECHANISM AND IMAGE FORMING APPARATUS

Abstract

A first operation restriction portion forms a first step between the first operation restriction portion and a first operation portion. A second operation restriction portion forms a second step between the second operation restriction portion and a second operation portion. A first locking portion releases locking of a locked portion when a first push of pushing the first operation portion or a second push of pushing the second operation portion is performed. When the sheet stopper is rotated in response to the first push, a second locking portion stops the sheet stopper in a first upright state. When the sheet stopper is rotated in response to the second push, the second locking portion allows the sheet stopper to rotate beyond the first upright state. A third locking portion stops the sheet stopper in a second upright state.

Description

INCORPORATION BY REFERENCE

This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2022-188923 filed on Nov. 28, 2022, the entire contents of which are incorporated herein by reference.

BACKGROUND

The present disclosure relates to a sheet stop mechanism provided in a discharge tray and an image forming apparatus comprising the same.

In an image forming apparatus, a sheet conveying device conveys a sheet along a sheet conveying path, and a printing device forms an image on the conveyed sheet. The sheet conveying device discharges the sheet from a sheet discharge port of the sheet conveying path to a discharge tray.

The image forming apparatus may include a sheet stop mechanism provided in the discharge tray. The sheet stop mechanism prevents the sheet from sliding off the discharge tray.

For example, it is known that the sheet stop mechanism rotatably supports a sheet stopper between a housed state and an upright state. The housed state is a state in which the sheet stopper is housed in a recess formed in the discharge tray. The upright state is a state in which the sheet stopper is erected from a sheet loading surface of the discharge tray in an obliquely upward direction on the downstream side of the sheet discharge direction.

SUMMARY

A sheet stop mechanism according to one aspect of the present disclosure is provided in a downstream end portion in a sheet discharge direction of a sheet loading surface configured to receive a sheet discharged from a sheet discharge port. The sheet stop mechanism includes a sheet stopper, a first operation restriction portion, a second operation restriction portion, a first locking portion, a second locking portion, and a third locking portion. The sheet stopper is supported rotatably around a shaft portion, and includes a movement restriction portion formed on a first side of the shaft portion and an operation portion and a locked portion formed on a second side of the shaft portion. The first operation restriction portion forms a first step between the first operation restriction portion and a first operation portion which is a part of the operation portion, and restricts downward movement of a finger which pushes down the first operation portion. The second operation restriction portion forms a second step larger than the first step between the second operation restriction portion and a second operation portion which is a part of the operation portion and restricts downward movement of the finger which pushes down the second operation portion. The first locking portion locks the locked portion to hold the sheet stopper in a housed state in which the movement restriction portion is housed in a recess formed in the sheet loading surface. Further, the first locking portion releases the locking of the locked portion by being elastically deformed by a force received from the locked portion when a first push of pushing down the first operation portion to a position of the first operation restriction portion or a second push of pushing down the second operation portion to a position of the second operation restriction portion is performed. When the sheet stopper is rotated in response to the first push, the second locking portion locks the locked portion to stop the sheet stopper in a first upright state in which the movement restricting portion extends from the sheet loading surface in an obliquely upward direction on a downstream side of the sheet discharging direction. Further, when the sheet stopper is rotated in response to the second push, the second locking portion is elastically deformed by a force received from the locked portion to allow the sheet stopper to rotate beyond the first upright state. When the sheet stopper is rotated beyond the first upright state, the third locking portion locks the locked portion to stop the sheet stopper in a second upright state in which an acute angle formed with respect to the sheet loading surface is smaller than that in the first upright state.

An image forming apparatus according to another aspect of the present disclosure includes a sheet conveying device, a printing device, a discharge tray, and the sheet stop mechanism. The sheet conveying device conveys a sheet along a sheet conveying path and discharges the sheet from a sheet discharge port of the sheet conveying path. The printing device forms an image on the sheet conveyed along the sheet conveying path. The discharge tray includes a sheet loading surface configured to receive the sheet discharged from the sheet discharge port. The sheet stop mechanism is provided in the discharge tray.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description with reference where appropriate to the accompanying drawings. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of an image forming apparatus including a sheet stop mechanism according to an embodiment.

FIG. 2 is a perspective view of the sheet stop mechanism according to the embodiment (first upright state).

FIG. 3 is a perspective view of the sheet stop mechanism according to the embodiment (housed state).

FIG. 4 is a perspective view of a sheet stopper in the sheet stop mechanism according to the embodiment.

FIG. 5 is a perspective view of a part of the sheet stopper and a support portion in the sheet stop mechanism according to the embodiment (housed state).

FIG. 6 is a side view of a part of the sheet stopper and the support portion in the sheet stop mechanism according to the embodiment (first upright state).

FIG. 7 is a side cross-sectional view of the sheet stop mechanism according to the embodiment (first upright state).

FIG. 8 is a side view of a part of the sheet stopper and the support portion in the sheet stop mechanism according to the embodiment (second upright state).

FIG. 9 is a side cross-sectional view of the sheet stop mechanism according to the embodiment (second upright state).

DETAILED DESCRIPTION

An embodiment of the present disclosure will be described below with reference to the drawings. It is noted that the following embodiment is an example of embodying the present disclosure and does not limit the technical scope of the present disclosure.

[Configuration of Image Forming Apparatus 10]

A sheet stop mechanism 5 according to the embodiment constitute a part of an image forming apparatus 10 (see FIG. 1).

The image forming apparatus 10 includes a sheet storing portion 2, a sheet conveying device 3, a printing device 4, and a housing 1. The housing 1 contains the sheet storing portion 2, the sheet conveying device 3, and the printing device 4.

The sheet conveying device 3 feeds a sheet 9 in the sheet storing portion 2 to a sheet conveying path 30 in the housing 1. Further, the sheet conveying device 3 conveys the sheet 9 along the sheet conveying path 30. Further, the sheet conveying device 3 discharges the sheet 9 from a sheet discharge port 101 of the sheet conveying path 30.

The sheet conveying device 3 includes a plurality of conveying roller pairs 31 each of which conveys the sheet 9 by rotating while nipping the sheet 9. The conveying roller pairs 31 include a discharge roller pair 31a disposed at the sheet discharge port 101.

The image forming apparatus 10 further includes a discharge tray 102. The discharge tray 102 is disposed on the top surface of the image forming apparatus 10.

The discharge roller pair 31a discharges the sheet 9 on which an image has been formed from the sheet discharge port 101 onto the top surface of the discharge tray 102. The top surface of the discharge tray 102 is a sheet loading surface 102c that receives the sheet 9 discharged from the sheet discharge port 101.

The sheet loading surface 102c is formed to incline upward from the lower end of a wall 103 extending downward from the sheet discharge port 101 in a sheet discharge direction D1.

In other words, the sheet loading surface 102c is formed to incline obliquely upward from a first end portion 102a on the upstream side of the sheet discharge direction D1 toward a second end portion 102b on the downstream side. The first end portion 102a is located below the sheet discharge port 101.

The sheet discharge direction D1 is a direction in which the sheet 9 is discharged from the sheet discharge port 101. In each figure, the width direction D2 is a direction that intersects the sheet discharge direction D1. In the present embodiment, the width direction D2 is a direction orthogonal to the sheet discharge direction D1.

The printing device 4 executes a printing process of forming an image on the sheet 9 conveyed along the sheet conveying path 30.

In the example shown in FIG. 1, the printing device 4 executes the printing process using an electrophotographic method. In this case, the printing device 4 includes a photoconductor 41, a charging device 42, a laser scanning unit 40, a developing device 43, a transfer device 44, a cleaning device 45, and a fixing device 46.

The charging device 42 charges the surface of the rotating photoconductor 41. The laser scanning unit 40 scans the surface of the charged photoconductor 41 with a laser beam to write an electrostatic latent image.

The developing device 43 supplies toner to the surface of the photoconductor 41 to develop the electrostatic latent image into a toner image. It is noted that the photoconductor 41 is an example of an image carrier that rotates while carrying the toner image.

The transfer device 44 transfers the toner image on the photoconductor 41 onto the sheet 9. The cleaning device 45 removes the toner remaining on the surface of the photoconductor 41. The fixing device 46 heats and presses the toner image on the sheet 9 to fix the toner image on the sheet 9.

The image forming apparatus 10 further includes a sheet stop mechanism 5. The sheet stop mechanism 5 is provided in the discharge tray 102 (see FIG. 1). Specifically, the sheet stop mechanism 5 is provided in the second end portion 102b of the sheet loading surface 102c (see FIG. 1).

The sheet stop mechanism 5 includes a sheet stopper 51 that prevents the sheet 9 from sliding off the sheet loading surface 102c (see FIG. 2 to FIG. 4). The sheet stopper 51 has a plate-shaped movement restriction portion 511 (see FIG. 2).

For example, the movement restriction portion 511 restricts the movement of the sheet 9 in the sheet discharge direction D1 by coming into contact with the leading end of the sheet 9 (see FIG. 7).

Alternatively, the movement restriction portion 511 restricts the movement of the sheet 9 in the sheet discharge direction D1 by supporting a portion of the sheet 9 near the leading end in a state of being inclined at an acute angle with respect to the sheet loading surface 102c (see FIG. 9).

The sheet stop mechanism 5 supports the sheet stopper 51 rotatably between a housed state and an upright state. FIG. 3 and FIG. 5 show the housed state, and FIG. 2 and FIG. 6 to FIG. 9 show the upright state.

The housed state is a state in which the movement restriction portion 511 of the sheet stopper 51 is housed in a recess 1020 formed in the sheet loading surface 102c (see FIG. 3 and FIG. 5). The upright state is a state in which the movement restriction portion 511 of the sheet stopper 51 is erected from the sheet loading surface 102c in an obliquely upward direction on the downstream side of the sheet discharge direction D1 (see FIG. 2 to FIG. 4).

When the sheet stopper 51 is in the upright state, the movement restriction portion 511 prevents the sheet 9 from sliding off the sheet loading surface 102c in the sheet discharge direction D1.

By the way, there are cases where it is desired to change the angle of the sheet stopper 51 in the upright state depending on the size of the sheet 9.

For example, it is desired that the sheet stop mechanism 5 be able to selectively hold the movement restriction portion 511 of the sheet stopper 51 at a first acute angle θ1 and a second acute angle θ2 with respect to the sheet loading surface 102c (see FIG. 7 and FIG. 9). The second acute angle θ2 is smaller than the first acute angle θ1.

For example, when the size of the sheet 9 is within a predetermined standard size, the upright state of the first acute angle θ1 is selected (see FIG. 7). This allows the movement restriction portion 511 to come into contact with the leading end of the sheet 9, thereby preventing the sheet 9 from sliding off the discharge tray 102.

On the other hand, when the size of the sheet 9 is larger than the standard size, the upright state of the second acute angle θ2 is selected (see FIG. 9).

A portion of the large-size sheet near the leading end rides up on the movement restriction portion 511 erected at the second acute angle θ2 (see FIG. 9). The movement restriction portion 511 thereby prevents the large-size sheet from sliding off the discharge tray 102.

Meanwhile, in the sheet stop mechanism 5, it is desired that the operation of selectively rotating the sheet stopper 51 from the housed state to one of the two types of upright states be simple.

[Sheet Stop Mechanism 5]

Hereinafter, a configuration of the sheet stop mechanism 5 will be described. The sheet stop mechanism 5 includes the sheet stopper 51 and a support portion 52 (see FIG. 2 and FIG. 3).

The sheet stopper 51 includes the movement restriction portion 511, a shaft portion 512, an operation portion 513, and a locked portion 514 (see FIG. 3 to FIG. 5).

The support portion 52 includes a bearing portion 520, a first locking portion 521, a second locking portion 522, and a third locking portion 523 (see FIG. 5, FIG. 6, and FIG. 8). Further, the support portion 52 includes a first operation restriction portion 524 and a second operation restriction portion 525 (see FIG. 3).

The sheet stopper 51 is supported rotatably around the shaft portion 512. The shaft portion 512 is provided along the width direction D2.

The movement restriction portion 511 is formed on a first side of the shaft portion 512, and the operation portion 513 and the locked portion 514 are formed on a second side of the shaft portion 512.

When the sheet stopper 51 is in the housed state, the movement restriction portion 511 is located upstream of the shaft portion 512 in the sheet discharge direction D1, and the operation portion 513 and the locked portion 514 are located downstream of the shaft portion 512 in the sheet discharge direction D1.

The operation portion 513 is a portion that is pushed down by a finger. The operation portion 513 includes a first operation portion 513a and a second operation portion 513b formed side by side in the width direction D2 (see FIG. 3). When the first operation portion 513a or the second operation portion 513b is pushed down, the sheet stopper 51 rotates in a first rotation direction R1 around the shaft portion 512.

When the sheet stopper 51 rotates in the first rotation direction R1 from the housed state, the movement restriction portion 511 rotates upward from within the recess 1020 and further rotates toward the downstream side of the sheet discharge direction D1.

When the sheet stopper 51 rotates in the first rotation direction R1 from the housed state, the operation portion 513 and the locked portion 514 rotate downward from a position along the sheet loading surface 102c and further rotate toward the upstream side of the sheet discharge direction D1.

The bearing portion 520 rotatably supports the shaft portion 512. In the present embodiment, one molded member 5200 of synthetic resin includes the bearing portion 520, the first locking portion 521, the second locking portion 522, the third locking portion 523, the first operation restriction portion 524, and the second operation restriction portion 525 (see FIG. 3 and FIG. 5).

The first operation restriction portion 524 and the second operation restriction portion 525 are formed side by side in the width direction D2. The first operation restriction portion 524 and the second operation restriction portion 525 are provided corresponding to the first operation portion 513a and the second operation portion 513b, respectively (see FIG. 3).

The first operation restriction portion 524 forms a first step S240 between itself and the first operation portion 513a. Thus, the first operation restriction portion 524 restricts the downward movement of the finger that pushes down the first operation portion 513a within the range of the first step S240.

The second operation restriction portion 525 forms a second step S250 between itself and the second operation portion 513b. Thus, the second operation restriction portion 525 restricts the downward movement of the finger that pushes down the second operation portion 513b within the range of the second step S250.

The second step S250 is a step larger than the first step S240 (see FIG. 3). Therefore, the sheet stopper 51 rotates with more force when the second operation portion 513b is pushed down than when the first operation portion 513a is pushed down.

In the following description, an operation of pushing down the first operation portion 513a to the position of the first operation restriction portion 524 will be referred to as a first push. Similarly, an operation of pushing down the second operation portion 513b to the position of the second operation restriction portion 525 will be referred to as a second push.

The first locking portion 521 locks the locked portion 514 of the sheet stopper 51. Thus, the first locking portion 521 holds the sheet stopper 51 in the housed state (see FIG. 5).

Specifically, the first locking portion 521 holds the sheet stopper 51 in the housed state by restricting the downward movement of the locked portion 514.

However, the first locking portion 521 is formed in a cantilever shape. Therefore, when the first locking portion 521 receives a force exceeding a first upper limit force from the locked portion 514, the first locking portion 521 is elastically deformed to a state of releasing the locking of the locked portion 514.

The user pushes down the first operation portion 513a or the second operation portion 513b with a force exceeding the first upper limit force.

When the first push or the second push is performed, the locked portion 514 applies a downward force to the first locking portion 521.

When the first push or the second push is performed, the first locking portion 521 is elastically deformed by the force received from the locked portion 514 to release the locking of the locked portion 514. Thus, the first locking portion 521 allows the locked portion 514 to rotate downward, and the sheet stopper 51 is rotated from the housed state in the first rotation direction R1 by the force of the first push or the second push (see FIG. 6 to FIG. 9).

When the locking of the locked portion 514 by the first locking portion 521 is released, the rotational force applied to the sheet stopper 51 by the second push is greater than the rotational force applied to the sheet stopper 51 by the first push.

That is, the sheet stopper 51 rotates in the first rotation direction R1 with more force when the second push is performed than when the first push is performed.

The second locking portion 522 locks the locked portion 514 when the sheet stopper 51 is rotated in response to the first push. Thus, the second locking portion 522 stops the sheet stopper 51 in the first upright state (see FIG. 6 and FIG. 7).

The first upright state is a type of the upright state, and is a state in which the movement restriction portion 511 forms a first acute angle θ1 with respect to the sheet loading surface 102c (see FIG. 6 and FIG. 7). For example, the first acute angle θ1 is in the range of 50 to 70 degrees.

However, the second locking portion 522 is formed in a cantilever shape. Therefore, when the second locking portion 522 receives a force exceeding a second upper limit force from the locked portion 514, the second locking portion 522 is elastically deformed to a state of releasing the locking of the locked portion 514.

The second upper limit force is larger than the force applied to the sheet stopper 51 by the first push and smaller than the force applied to the sheet stopper 51 by the second push.

Accordingly, when the sheet stopper 51 is rotated in response to the second push, the second locking portion 522 is elastically deformed by the force received from the locked portion 514. Thus, the second locking portion 522 allows the locked portion 514 to rotate in the first rotation direction R1 beyond the position of the second locking portion 522 (see FIG. 8 and FIG. 9).

That is, when the sheet stopper 51 is rotated in response to the second push, the second locking portion 522 allows the sheet stopper 51 to rotate in the first rotation direction R1 beyond the first upright state (see FIG. 8 and FIG. 9).

The third locking portion 523 locks the locked portion 514 when the sheet stopper 51 is rotated in the first rotation direction R1 beyond the first upright state (see FIG. 8). The third locking portion 523 locks the locked portion 514 to stop the sheet stopper 51 in a second upright state (see FIG. 8 and FIG. 9).

The second upright state is a type of the upright state, and is a state in which the movement restriction portion 511 forms a second acute angle θ2 with respect to the sheet loading surface 102c (see FIG. 8 and FIG. 9). For example, the second acute angle θ2 is in the range of 20 to 40 degrees.

By employing the sheet stop mechanism 5, it is possible to selectively rotate the sheet stopper 51 from the housed state to one of the two upright states by a simple single operation. The simple single operation is the first push or the second push.

On the other hand, when the sheet stopper 51 is in the first upright state or the second upright state, the movement restriction portion 511 is pushed down in a second rotation direction R2. The second rotation direction R2 is the opposite direction of the first rotation direction R1.

When the movement restriction portion 511 is pushed down in the second rotation direction R2, the sheet stopper 51 rotates from the first upright state or the second upright state to the housed state.

It is to be understood that the embodiments herein are illustrative and not restrictive, since the scope of the disclosure is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims.

Claims

1. A sheet stop mechanism provided at a downstream end portion in a sheet discharge direction of a sheet loading surface configured to receive a sheet discharged from a sheet discharge port, the sheet stop mechanism comprising: a sheet stopper supported rotatably around a shaft portion, and including a movement restriction portion formed on a first side of the shaft portion and an operation portion and a locked portion formed on a second side of the shaft portion;a first operation restriction portion configured to form a first step between the first operation restriction portion and a first operation portion which is a part of the operation portion and restrict downward movement of a finger which pushes down the first operation portion;a second operation restriction portion configured to form a second step larger than the first step between the second operation restriction portion and a second operation portion which is a part of the operation portion and restrict downward movement of the finger which pushes down the second operation portion;a first locking portion configured to lock the locked portion to hold the sheet stopper in a housed state in which the movement restriction portion is housed in a recess formed in the sheet loading surface, and release the locking of the locked portion by being elastically deformed by a force received from the locked portion when a first push of pushing down the first operation portion to a position of the first operation restriction portion or a second push of pushing down the second operation portion to a position of the second operation restriction portion is performed;a second locking portion configured to, when the sheet stopper is rotated in response to the first push, lock the locked portion to stop the sheet stopper in a first upright state in which the movement restriction portion extends from the sheet loading surface in an obliquely upward direction on a downstream side of the sheet discharge direction and, when the sheet stopper is rotated in response to the second push, be elastically deformed by a force received from the locked portion to allow the sheet stopper to rotate beyond the first upright state; anda third locking portion configured to, when the sheet stopper is rotated beyond the first upright state, locks the locked portion to stop the sheet stopper in a second upright state in which an acute angle formed with respect to the sheet loading surface is smaller than that in the first upright state.

2. The sheet stop mechanism according to claim 1, wherein the first operation portion and the second operation portion are formed side by side in a width direction that intersects the sheet discharge direction, andthe first operation restriction portion and the second operation restriction portion are formed side by side in the width direction.

3. The sheet stop mechanism according to claim 1, wherein one molded member made of synthetic resin includes the first locking portion, the second locking portion, the third locking portion, and a bearing portion configured to support the shaft portion formed in the sheet stopper.

4. An image forming apparatus comprising: a sheet conveying device configured to convey a sheet along a sheet conveying path and discharge the sheet from a sheet discharge port of the sheet conveying path;a printing device configured to form an image on the sheet conveyed along the sheet conveying path;a discharge tray including a sheet loading surface configured to receive the sheet discharged from the sheet discharge port; andthe sheet stop mechanism according to claim 1 which is provided in the discharge tray.