This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2016-061176 filed on Mar. 25, 2016, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a sheet storage device and an image forming apparatus including thereof.
A typical image forming apparatus includes a sheet storage device that stores sheets that are fed by a sheet feed portion including a pick-up roller. The sheet storage device is provided as a sheet cassette which is attached to a main body of the image forming apparatus in a detachable manner.
In many cases, the sheet storage device includes a lift portion that is configured to be lifted and lowered, and push up stacked sheets toward the sheet feed portion that is provided above.
In addition, the sheet storage device may include a lift attachment that is attached to the lift portion in a detachable manner. The lift attachment is attached to the lift portion when a special sheet, such as an envelope, that is nonuniform in thickness, is stored in the sheet storage device.
A sheet storage device according to an aspect of the present disclosure stores sheets that are fed by a sheet feed portion, and includes a case, a lift plate, and a lift attachment. The case stores the sheets. The lift plate is provided on a bottom plate of the case in such a way as to be lifted and lowered, and configured to push up the sheets stacked on an upper surface of the lift plate toward the sheet feed portion that is provided above. The lift attachment is fixed, in a detachable manner, to an end portion of an upper surface of the lift plate on a downstream side in a sheet feed direction, at a central portion of the upper surface in a width direction, and configured to support a lower surface of the sheets stacked on the lift plate at a position higher than the upper surface of the lift plate, the width direction being perpendicular to the sheet feed direction. The lift attachment includes a base portion and a pair of arm portions. The base portion is formed to extend along the sheet feed direction, and smaller than the lift plate in size in the width direction. The pair of arm portions are respectively formed to extend from an end portion of the base portion that is on a downstream side in the sheet feed direction, to opposite directions in the width direction, along an edge of the lift plate that is on the downstream side in the sheet feed direction.
An image forming apparatus according to another aspect of the present disclosure includes the sheet storage device, a sheet feed portion, and an image forming portion. The sheet feed portion feeds the sheets stored in the sheet storage device one by one into a sheet conveyance path. The image forming portion forms an image on a sheet that has been fed into the sheet conveyance path.
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.
The following describes an embodiment of the present disclusure with reference to the accompanying drawings. It should be noted that the following embodiment is an example of a specific embodiment of the present disclosure and should not limit the technical scope of the present disclosure.
[Image forming apparatus 10]
As shown in
The sheet storage device 2 is a so-called sheet cassette. A lower portion of the main body 1 constitutes a device attachment portion 11 to which the sheet storage device 2 is attached in a detachable manner. The sheet storage device 2 is drawably attached to the device attachment portion 11. The sheet storage device 2 stores sheets 9 that are fed one by one by a sheet feed portion 14 provided in the device attachment portion 11 (see
The sheet feed portion 14 includes a pick-up roller 14a, a fed sheet guide 14b, and a pair of feed rollers 14c. The pick-up roller 14a feeds the topmost one of the sheets 9 stacked in the sheet storage device 2 toward the pair of feed rollers 14c.
The fed sheet guide 14b supports the pick-up roller 14a, and guides the sheet 9 from under the pick-up roller 14a toward the pair of feed rollers 14c. The pair of feed rollers 14c feed the sheet 9 sent from the pick-up roller 14a, into a sheet conveyance path 15 in the main body 1.
In the following description, a direction in which a sheet 9 in the sheet storage device 2 is fed by the sheet feed portion 14 is referred to as a feed direction D0, and a horizontal direction perpendicular to the feed direction D0 is referred to as a width direction D1.
The main body 1 includes an image forming portion 12 which is configured to form an image on a sheet 9 fed from the sheet storage device 2 into the sheet conveyance path 15. The image forming portion 12 forms an image on the sheet 9, and discharges the sheet 9 after image formation to a discharge tray 13 that is provided between the main body 1 and the image reading portion 1x.
The sheet storage device 2 includes a case 20, a lift portion 23, and a lift supporting portion 26. As shown in
As shown in
A pair of lateral guides 24 are attached to the bottom plate portion 21. The pair of lateral guides 24 are respectively applied to opposite ends of the sheets 9 in the width direction D1 in the case 20. Furthermore, a rear end stopper 25 is attached to the bottom plate portion 21. The rear end stopper 25 is applied to a rear end of the sheets 9. It is noted that the rear end of the sheets 9 is an end located on the upstream side in the feed direction D0.
The pair of lateral guides 24 are attached to the bottom plate portion 21 so as to be displaced along the width direction D1 by a rack and pinion mechanism. When one of the pair of lateral guides 24 is displaced along the width direction D1, the other lateral guide 24 is displaced in the opposite direction by the act of the rack and pinion, by the same displacement amount. In addition, the rear end stopper 25 is attached so as to be displaced along the feed direction D0 with respect to the lift portion 23.
The lift portion 23 is provided on the bottom plate portion 21 of the case 20 in such a way as to be lifted and lowered, and push up the stacked sheets 9 toward the pick-up roller 14a of the sheet feed portion 14 that is provided above. The lift portion 23 is made of a metal, for example.
The lift portion 23 is supported so as to be pivoted in the up-down direction with a pair of shaft portions 23a as a fulcrum, the pair of shaft portions 23a being located close to the first side wall portion 22a of the case 20.
The lift supporting portion 26 is supported by the case 20 so as to pivot in the up-down direction, and supports the lift portion 23 from below. When the sheet storage device 2 is attached to the device attachment portion 11, a driving shaft 26a at the base of the lift supporting portion 26 is coupled with a shaft of a lift motor 16 provided in the device attachment portion 11 by a gear mechanism (not shown). The driving shaft 26a is rotated by a power of the lift motor 16.
When the lift motor 16 rotates in a forward rotation direction, the lift supporting portion 26 pivots in a first direction around the driving shaft 26a, thereby causing the lift portion 23 to pivot toward the sheet feed portion 14. On the other hand, when the lift motor 16 rotates in a reverse rotation direction, the lift supporting portion 26 pivots in a second direction around the driving shaft 26a, thereby causing the lift portion 23 to pivot downward.
The sheet storage device 2 includes a lift attachment 3 that is represented by an imaginary line (a two-dot chain line) in
Meanwhile, to meet the demand for space saving and cost reduction, it is required to realize, in a simple configuration, the sheet storage device 2 that can accommodate both regular sheets 9 that are uniform in thickness, and special sheets 90 such as envelopes. In the following, a configuration of the sheet storage device 2 corresponding to such a request is described.
As shown in
As shown in
As shown in
When the lift attachment 3 is attached to or detached from the lift portion 23, the root portions of the engaging portions 34 are elastically deformed. This allows the engaging portions 34 to be displaced between a position to be hooked to the rims of the attachment holes 23b of the lift portion 23, and a position to pass over the attachment holes 23b.
In a state where the lift attachment 3 is attached to the lift portion 23, the pair of arm portions 32 extend from a first end portion 31a of the base portion 31 that is on the downstream side in the feed direction D0, to opposite directions in the width direction D1 (see
The base portion 31 is smaller than the pick-up roller 14a in size in the width direction D1. As a result, the base portion 31 supports the sheets 9 from below in a range in the width direction D1 that constitutes a part of a range of contact in the width direction D1 where the pick-up roller 14a contacts the sheet 9. In addition, the pair of arm portions 32 have a role of extending the range of support in the width direction D1 for supporting the sheets 9 from below at a position on the downstream side in the feed direction D0. It is noted that as shown in
In the special sheet 90 such as an envelope, a side end portion 90c which is at one of opposite ends in the width direction D1, is thicker than the other portions (see
The upper surfaces of the base portion 31 and the pair of arm portions 32 support the lower surface of the lowest special sheet 90 of the stacked special sheets 90. The base portion 31 supports the lower surface of the special sheet 90 via the friction pad 33 stuck on the upper surface of the base portion 31.
As shown in
The side end portion 90c of the special sheet 90 may be thicker than the other portions of the special sheet 90 in a case where the special sheet 90 is an envelope and the side end portion 90c includes a flap folded and overlapping the body portion of the envelope. In this case, when the special sheets 90 are stacked directly on a flat upper surface of the lift portion 23, the side end portion 90c of the topmost special sheet 90 is higher than the other portions. In such a situation, the special sheet 90 may not be fed out smoothly by the sheet feed portion 14 since a large frictional resistance is generated between the side end portion 90c and the fed sheet guide 14b.
On the other hand, as shown in
It is noted that the height of the side end portion 90c of the topmost special sheet 90 increases temporarily above the pair of arm portions 32. Here, the pair of arm portions 32 are located below the pick-up roller 14a or on the downstream side of the pick-up roller 14a in the feed direction D0. With this configuration, the side end portion 90c of the topmost special sheet 90 becomes temporarily high after passing an end portion of the fed sheet guide 14b on the upstream side in the feed direction D0. As a result, the frictional resistance between the side end portion 90c and the fed sheet guide 14b is reduced to a relatively small value.
The pair of arm portions 32 play a role of preventing a feeding error of special sheets 90 when a small number of special sheets 90 are placed on the lift attachment 3. This is described in the following.
As shown in
The pair of arm portions 32 are disposed directly below or near directly below the pick-up roller 14a to support the special sheets 90 from below in a wide range in the width direction D1. With this configuration, even when a small number of special sheets 90 are stacked on the lift attachment 3, a sufficient contact area is secured between the pick-up roller 14a and the topmost special sheet 90. This prevents a feeding error of the special sheet 90.
Furthermore, the pair of arm portions 32 prevent the special sheets 90 from being displaced in the width direction D1 due to deviation in weight between opposite sides of the special sheets 90 in the width direction D1.
In addition, as shown in
The pair of arm portions 32 are configured to pivot around support shafts 31d formed on corners in the first end portion 31a of the base portion 31, respectively. The lift attachment 3 is attached to the lift portion 23 in a state where the pair of arm portions 32 are in the extension position.
With the configuration where the pair of arm portions 32 are pivotably coupled with the base portion 31, it is possible to house the lift attachment 3 compactly when unused, without increasing the number of parts.
In addition, as shown in
When the two engaging portions 34 are inserted in the two attachment holes 20a, the lift attachment 3 is fixed to the third side wall portion 22c in a detachable manner. That is, the two engaging portions 34 serve as both a fastening mechanism for the lift portion 23, and a fastening mechanism for the case 20. It is noted that a portion of the third side wall portion 22c including the two attachment holes 20a is an example of the attachment housing portion.
As shown in
When the sheet storage device 2 is adopted, it is possible to deal with, with ease, both the sheets 9 that are uniform in thickness and the special sheets 90 such as evelopes by attaching and detaching the lift attachment 3. In addition, the lift attachment 3 can be produced by a relatively simple resin molding and has a simple configuration.
It is noted that the attachment holes 20a may be formed in an inner side surface of the exterior member 220. In this case, the exterior member 220 is an example of the frame portion.
In addition, since the lift attachment 3, when unused, is fixed to a part of the case 20, the lift attachment 3 is prevented from generating an abnormal sound when the sheet storage device 2 is attached or detached, or during carriage of the image forming apparatus 10.
The lift attachment 3 may be composed of two elemental members that are coupled in a separable manner. For example, a first elemental member may include the pair of arm portions 32 and a part of the base portion 31 between the arm portions 32, and a second elemental member may include the other portions of the lift attachment 3.
In the above-described case, a coupling mechanism similar to the engaging portions 34 and the attachment holes 23b may be formed in the first elemental member and the second elemental member.
It is noted that the sheet storage device and the image forming apparatus 10 of the present disclosure may be configured by freely combining, within the scope of claims, the above-described embodiments and application examples, or by modifying the embodiments and application examples or omitting a part thereof.
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.
Number | Date | Country | Kind |
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2016-061176 | Mar 2016 | JP | national |