Patent Application
20180297796
The present invention relates to a sheet storing apparatus, a sheet feeding apparatus, and an image forming apparatus.
An image forming apparatus such as a copier, a printer, and a facsimile machine of a sort of feeding a sheet to an image forming unit from a sheet feeding apparatus to form an image on the sheet is being widely spread today. In general, the sheet feeding apparatus includes a sheet feed cassette, i.e., a sheet storing apparatus, removably attached to an apparatus body and feeds the sheet stored in the sheet feed cassette to the image forming unit by a sheet feed roller.
Some of the sheet feed cassette used in the sheet feeding apparatus includes a sheet supporting plate liftably provided to stack a sheet and to press the sheet against a sheet feed roller for example. The sheet feed cassette is provided with a rear end regulating portion configured to regulate a position of a rear end in a sheet feed direction of the sheet (referred to as a ‘rear end’ hereinafter) stored in the sheet feed cassette which is configured to be able to store different size sheets. The sheet feed cassette is also provided with a pair of side regulating members configured to regulate side end positions in a direction orthogonal to the sheet feed direction (referred to as a ‘width direction’ hereinafter) of the sheet stored in the sheet feed cassette.
Such sheet feed cassette is configured to regulate the rear end of the sheet by the rear end regulating portion while regulating the side ends of the sheet by the pair of side regulating members to regulate a front end position of the sheet always at a predetermined position. This arrangement makes it possible to feed the sheet from a same position and to feed the sheet stably when the sheet feed cassette is stored in an apparatus body.
In the conventionally sheet feed cassette, there is a case when the sheet stacked on the sheet supporting plate floats above an upper end of the side regulating portion during when the sheet supporting plate rises. The sheet is conveyed askew if the sheet is fed in this condition. Then, in order to regulate the sheet from floating up as described above, a tab-shaped member is provided at an upper end of a unit body regulating a side end of a sheet to press the sheet from above and to regulate the sheet from getting over the upper end of the unit body as disclosed in Japanese Patent Application Laid-open No. 2011-57450.
As another arrangement, a curl presser portion is turnably attached to a front end of a regulating surface of a regulating member configured to regulate a side end of a sheet to regulate a curled part of the sheet from getting over the upper end of the regulating member by the curl presser portion as disclosed in Japanese Patent Laid-open No. 2001-88970 for example. The curl presser portion presses the curled part at an end of the stacked sheet by being held at a position approximately at a right angle with respect to the regulating surface by an urging member.
By the way, in the case of the arrangement of pressing the sheet by the tab-shaped member, it is necessary to store the sheet while avoiding the tab-shaped member so as not to damage the sheet in storing the sheet because the tab-shaped member is fixed to the unit body. Thus, storability of the sheet deteriorates.
Meanwhile, in the case of the arrangement of pressing the sheet by the curl presser portion, the storability of the sheet does not deteriorate in storing the sheet because the curl presser portion turns downward by resisting against an urging force of the urging member by being pressed from above by the stored sheet. However, this arrangement requires a plurality of components, thus leading to an increase of cost and to deterioration of assemblability.
According to a first aspect of the invention, a sheet feeding apparatus includes a sheet feed portion configured to feed a sheet and a sheet storing apparatus configured to store the sheet to be fed by the sheet feed portion and including a side regulating portion configured to regulate a position of the sheet by abutting with a side end of the sheet stored in the sheet storing apparatus. The side regulating portion includes a body portion including an inner wall surface facing the sheet, a pressing portion capable of projecting out of the body portion and of pressing the side end of the sheet, a regulating portion formed integrally with an upper part of the pressing portion so as to project to a sheet side and regulating an upward move of the sheet stored in the sheet storing apparatus, an urging portion configured to urge the pressing portion such that the pressing portion projects out of the body portion so that the pressing portion presses the side end of the sheet, and a holding portion configured to hold the pressing portion movably from a project position where the pressing portion projects out of the body portion to a retract position where the regulating portion enters within the body portion by resisting against the urging member when the regulating portion is pressed from above.
According to a second aspect of the invention, a sheet storing apparatus includes a body configured to store a sheet, and a side regulating portion configured to abut against a side end of the stored sheet to regulate a position of the sheet. The side regulating portion includes a body portion including a regulating surface facing the side end of the sheet to regulate the side end of the sheet, a pressing member comprising a pressing portion projectable/retractable from the body portion and capable of pressing the side end of the sheet, and a regulating portion formed integrally with an upper part of the pressing portion so as to project to a widthwise inner side and regulating an upward move of the sheet stored in the sheet storing apparatus, an urging member configured to urge the pressing member such that the pressing member projects out of the body portion so that the pressing portion presses the side end of the sheet, and a holding portion configured to hold the pressing member movably from a project position where the pressing member projects out of the body portion to a retract position where the regulating portion enters within the body portion by resisting against the urging member when the regulating portion is pressed from above.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Embodiments of the present disclosure will be described in detail below with reference to the drawings.
The image forming unit 200B is provided with a photosensitive drum 212, a laser scanner 232, and others. The sheet feeding apparatus 200C is provided with a sheet feed cassette 300 serving as a sheet storing apparatus storing the sheet S and a pickup roller 202 serving as a sheet feed portion feeding the sheet stored in the sheet feed cassette 300.
In response to a feed signal outputted from a controller not illustrated to the sheet feeding apparatus 200C in the image forming apparatus 200 constructed as described above, the sheet S is fed by the pickup roller 202 from the sheet feed cassette 300. After that, the sheet S fed as described above is separated one by one by a feed roller 203 and a retard roller 204 and is conveyed to a pre-registration roller pair 209 and a registration roller pair 210 through an upper drawing roller pairs 205 and 206 and an upper conveyance roller pairs 207 and 208. While there is a case when the sheet S is conveyed askew by being affected by a conveyance load, variation of precision of components or the like in the process being conveyed to the pre-registration roller pair 209, the skew is removed by a holding force and a registration shutter mechanism not illustrated of the registration roller pair 210. After that, a top sensor 211 detects the sheet S whose skew has been corrected.
Meanwhile, based on a signal from the top sensor 211, the controller irradiates the photosensitive drum 212 with a laser beam corresponding to an image signal from the laser scanner 232. At this time, by being irradiated with the laser beam, the photosensitive drum 212 which has been electrified in advance forms an electrostatic latent image thereon. Then, a toner image is formed on the photosensitive drum 212 by developing the electrostatic latent image by toner.
The toner image is transferred onto a predetermined position on the sheet S when the sheet S is conveyed to a transfer nip portion composed of a transfer roller 213 and the photosensitive drum 212 by conducting the exposure and scanning by utilizing the signal of the top sensor 211. Then, the toner image is transferred onto the sheet S by the transfer roller 213. Thus, a transferred image is formed on the sheet S.
Next, the sheet S onto which the toner image has been transferred is conveyed to a fixing unit 200D including a fixing roller 215 and a pressure roller 216. By undergoing heat and pressure applied in the fixing unit 200D, the toner melts and the transferred image is fixed on the sheet S. Here, when the sheet S is conveyed to the fixing unit 200D and is conveyed by both fixing and transfer nip portions, it is necessary to avoid the image being transferred from being affected by differences of conveying velocities of the photosensitive drum 212, the transfer roller 213, the fixing roller 215 and the pressure roller 216. To that end, the controller gives the sheet S with an adequate amount of sag between the transfer and fixing rollers by controlling the velocity of the pressure roller 216 by utilizing a signal of a loop sensor 214 to control so that the amount is kept always at the adequate amount during when the sheet is conveyed between the transfer roller 213 and the fixing roller 215.
After that, the fixed sheet S is conveyed by a conveyance roller 218 and is lead to a face down (FD) sheet discharge passage P1 by being switched by a switching member 219 in a case of a simplex printing mode. Then, the sheet S is discharged out of the image forming apparatus body 200A through an intermediate sheet discharge roller pair 220 and a face down (FD) sheet discharge roller pair 222 and is stacked on a face down (FD) sheet discharge tray 224. It is noted that the image forming apparatus 200 of the present embodiment has a duplex printing mode of forming images on both surfaces of the sheet.
In the case of the duplex printing mode, the sheet S which has passed through the fixing unit 200D is lead to a branch passage P2 by being switched by the switching member 219 at first. Then, the sheet S is conveyed by a conveyance roller 225 to a reversing roller 227 and to a duplex printing passage P3 by reverse rotation of the reversing roller 227 and switching made by a switching member not illustrated. After that, the sheet S is conveyed to the pre-registration roller pair 209 again by conveyance rollers 229, 230, and 231 provided along the duplex printing passage P3 to transfer and fix a toner image again onto another side of the sheet S. Then, the sheet S is discharged by the intermediate sheet discharge roller pair 220 and the FD discharge roller pair 222.
As illustrated in
The sheet supporting plate 309 is provided in the cassette body 310 turnably in the vertical direction centering on a turning center 309a and is provided with a separation sheet 308 pasted at a front end part on a downstream end side in the sheet feed direction of an upper surface thereof. The sheet supporting plate 309 is provided with a push-up plate 314 for pushing up the sheet supporting plate 309 under the sheet supporting plate 309.
It is noted that the image forming apparatus body 200A is provided with a lift mechanism not illustrated for turning the sheet supporting plate 309 upward by driving the push-up plate 314. Then, in response to a timing when a user inserts the sheet feed cassette 300 into the image forming apparatus body 200A after storing sheets in the sheet feed cassette 300, a drive of the lift mechanism is transmitted to the push-up plate 314 so that the push-up plate 314 turns upward and the sheet supporting plate 309 turns upward by being pressed by the push-up plate 314. Thereby, the sheet on the sheet supporting plate is pressed against the pickup roller 202 described and illustrated in
The rear end regulating member 304 moves in the sheet feed direction along a guide portion 316 provided along the sheet feed direction on a bottom surface of the cassette body 310. The rear end regulating member 304 also includes a rear end regulation manipulating lever 313 that can be engaged/disengaged to the guide portion 316. The engagement with the guide portion 316 is released by pinching the rear end regulation manipulating lever 313. After that, the rear end regulating member 304 moves by moving the rear end regulation manipulating lever 313 along the sheet feed direction while pinching the rear end regulation manipulating lever 313.
The first and second side regulating plates 303 and 305 are provided with body portions 303a and 305a having inner wall surfaces respectively facing widthwise end portions of the sheet. It is noted that the inner wall surface may be also called as a regulating surface for regulating the side end of the sheet. The first and second side regulating plates 303 and 305 are attached with racks 307a and 307b extending respectively in the width direction. The racks 307a and 307b are meshed with a pinion gear not illustrated and located at a widthwise center part on the bottom surface of the cassette body 310.
The first side regulating plate 303 also includes a side regulation manipulating lever 312 disengageably engaging with a lock portion not illustrated provided along the width direction on the bottom surface of the cassette body 310. The engagement with the lock portion not illustrated is released by pinching the side regulation manipulating lever 312. After that, the first and second side regulating plates 303 and 305 move in the width direction symmetrically centering on the pinion gear by moving the side regulation manipulating lever 312 along the width direction while pinching the side regulation manipulating lever 312.
Sheets of various sizes can be stored in the sheet feed cassette 300 by movably providing the rear end regulating member 304 and the first and second side regulating plates 303 and 305. The sheet can be positioned in setting the sheet by moving the rear end regulating member 304 and the first and second side regulating plates 303 and 305 to the position corresponding to a sheet size.
Here, as illustrated in
The first side regulating plate 303 is provided with a pressing member 301 projectably/retractably from the body portion 303a. The pressing member 301 is configured to be held projectably/retractably by a holder member 302 which is a holding portion provided in the first side regulating plate 303 and to be urged projectably from the body portion 303a by a urging member 315 provided between the holder member 302 and the pressing member 301. By being pressed by the pressing member 301 urged thus by the urging member 315, the sheet is pressed against the body portion 305a of the second side regulating plate 305.
Even if a gap is generated between the sheet stored in the cassette and the first and second side regulating plates 303 and 305, it is possible to press the sheet against the second side regulating plate 305 by thus pressing the sheet against the body portion 305a of the second side regulating plate 305. That is, according to the present embodiment, the sheet is pressed against the second side regulating plate 305 to regulate the position of the sheet. Then, the sheet stored in the cassette can be fed from a fixed position by making the second side regulating plate 305 as a standard in feeding the sheet.
As illustrated in
Long holes 302a which are support portions extending respectively in a horizontal direction are defined through opposing widthwise inner wall surfaces of the holder member 302. Then, the pressing member 301 is held by the holder member 302 movably along the long holes 302a and turnably centering on the bosses 301c by slidably supporting the bosses 301c of the pressing member 301 by the long holes 302a.
Still further, the holder member 302 is provided with first and second stoppers 302c and 302d as illustrated in
Next, an operation of the pressing member 301 will be described with reference to
The user stores the sheet in the sheet feed cassette 300 in this condition. It is noted that the user stores the sheet by operating the side regulation manipulating lever 312 and the rear end regulation manipulating lever 313 in advance corresponding to size of the sheet to move and fix the first and second side regulating plates 303 and 305 and the rear end regulating member 304 at a position corresponding to the size of the sheet. The user stores the sheet from above after that.
Here, the height regulating portion 301a is provided so as to project by the predetermined amount from the upper end of the abutment surface 3011a as described above. Due to that, when the sheet is stored from above, the sheet abuts against the height regulating portion 301a and the height regulating portion 301a is pressed by a force F from above by the sheet. Due to the force F, the pressing member 301 located at the project position projecting from the body portion 303a turns centering on the boss 301c as illustrated in
It is noted that when the height regulating portion 301a enters completely within the holder member 302, the first side regulating plate 303 is in flush with the body portion 303a. Still further, the abutment portion 301b abuts against the second stopper 302d of the holder member 302 at this time, so that the pressing member 301 stops.
Thus, it is possible to prevent the height regulating portion 301a from deteriorating the storability of the sheet in storing the sheet by arranging such that the pressing member 301 moves in a direction in which the height regulating portion 301a retracts while turning by being pressed by the sheet and such that the height regulating portion 301a enters within the holder member 302. That is, it is possible to prevent the storability of the sheet from deteriorating by configuring the pressing member 301 so as to be turnable and movable from the project position to the retract position.
As described above, according to the present embodiment, the height regulating portion 301a is integrally formed with the pressing member 301 and the pressing member 301 is provided turnably with respect to the first side regulating plate 303 and movably to the project and retract positions. Thereby, when the sheet abuts with the height regulating portion 301a when the sheet is stored in the sheet feed cassette 300 and the height regulating portion 301a is pressed from above by the sheet, the pressing member 301 turns and moves to the retract position. Then, because the pressing member 301 thus turns and moves to the retract position, it is possible to store the sheet while setting the first and second side regulating plates 303 and 305 at a position corresponding to size of the sheet. Thus, this arrangement makes it possible to prevent the storability of the sheet from being deteriorated also in such a case.
Still further, because the height regulating portion 301a moves to the position in flush with the body portion 303a of the first side regulating plate 303 in maximum in storing the sheet, it is possible to prevent an edge of the sheet from being damaged by the height regulating portion 301a in storing the sheet. Still further, the pressing member 301 is configured such that the pressing member 301 retracts while turning by receiving the force from the sheet. In other words, the holder member 302 holds the pressing body portion 3011 movably from the project position to the retract position while inclining with respect to the regulating surface. This arrangement makes it possible to move the pressing member 301 to the retract position even if the force applied to the pressing member 301 is small.
This arrangement makes it possible to move the pressing member 301 to the retract position even if the position where the sheet is set varies and the force applied to the pressing member 301 becomes small. As a result, it becomes unnecessary to provide a tapered height regulating portion by considering the variation of the position where the sheet is set. Accordingly, it is possible to prevent the height regulating portion from being enlarged in width and height directions and along with that, to downsize the first side regulating plate 303 and the sheet feed cassette 300.
Next, a second embodiment of the present disclosure will be described.
According to the present embodiment, the long holes 302a of the holder member 302 are inclined obliquely downward such that a downstream side thereof in the retract direction is lowered as illustrated in
Thereby, when the height regulating portion 301a illustrated in
After that, when the storage of the sheet is completed, no force is applied to the pressing member 301 from above by the sheet. Then, the pressing member 301 moves obliquely upward by the urging force of the urging member 315 and presses the side end in the width direction of the sheet with a constant force as illustrated in
After that, the sheet supporting plate 309 rises and the sheet is pressed against the pickup roller after attaching the sheet feed cassette 300 in which the sheet has been stored to the image forming apparatus body 200A. At this time, as illustrated in
As described above, according to the present embodiment, the long holes 302a are defined aslant such that the downstream side in the retract direction is lowered. This arrangement makes it possible to efficiently transmit the pressing force of the sheet to the pressing member 301 and to move the pressing member 301 in the retract direction more smoothly when the pressing member 301 is pressed by the sheet to be stored. Still further, because the pressing member 301 is configured so as to move in the oblique direction, it is possible to shorten a length in the width direction of the first side regulating plate 303 and to downsize the first side regulating plate 303 and the sheet feed cassette 300.
Next, a third embodiment of the present disclosure will be described.
As illustrated in
Next, an operation of the pressing member 301 will be described with reference to
If the height regulating portion 301a receives a force F from the sheet stored in this condition, the pressing member 301 moves obliquely downward along the bottom surface 302b1 by a component of the force F while turning centering on the boss 301c as illustrated in
Here, an amount of the sheets that can be stored in the sheet feed cassette 300 will be described. According to the present embodiment, the sheets can be stored up to a position S1 illustrated in
In
The position of the uppermost sheet S1 can be heightened and more sheets can be stored by holding the pressing member 301 by the opening portion 302b defined as described above in the present embodiment. It is noted that it is necessary to keep a certain gap between the uppermost sheet S1 and the height regulating portion 301a as described above in the condition of
As described above, according to the present embodiment, the more sheets can be stored by supporting the pressing member 301 by the opening portion 302b in which the space x enabling the boss 301c to move upward is defined between the bottom surface 302b1 and the top surface 302b2. Still further, in a case when a number of sheets to be stacked in the sheet feed cassette 300 is determined to be 500 sheets for example, the configuration of the present embodiment makes it possible to lower the height of the first side regulating plate 303 and to downsize the sheet feed cassette 300 in the vertical direction.
Next, a fourth embodiment of the present disclosure will be described.
According to the present embodiment, two (plurality of) bosses 301c are arrayed in the vertical direction through both side wall surfaces in the width direction of the pressing member 301. Still further, two (plurality of) long holes 302a inclined such that the downstream side in the retract direction is lowered are defined in the vertical direction and in parallel through inner wall surfaces opposing in the width direction of the holder member 302. Then, the pressing member 301 is held by the holder member 302 movably while keeping the same attitude along the long holes 302a by slidably attaching the bosses 301c of the pressing member 301 respectively to the plurality of long holes 302a.
Thereby, as illustrated in
When the storage of the sheets is completed after that, no force is applied to the pressing member 301 from above by the sheets. Due to that, the pressing member 301 obliquely upward by the urging member 315 and presses the side end in the width direction of the sheet with a constant force as illustrated in
After that, the sheet supporting plate 309 rises and the sheets are pressed against the pickup roller after attaching the sheet feed cassette 300 in which the sheet has been stored to the image forming apparatus body 200A. At this time, as illustrated in
As described above, because the two long holes 302a are defined in parallel and obliquely in the present embodiment, the pressing force of the sheet can be efficiently transmitted to the pressing member 301 in pressing the pressing member 301 from above by the sheets to be stored. This arrangement makes it possible to move the pressing member 301 smoothly in the retract direction. It is also possible to shorten the widthwise length of the first side regulating plate 303 and to downsize the sheet feed cassette 300 by causing the pressing member 301 to retract in the oblique direction. It is noted that although the long holes 302a obliquely defined are used as the support portion supporting the bosses 301c of the pressing member 301 in the present embodiment, the opening portion 302b of the third embodiment described above may be also used as the support portion.
Still further, although the configuration which enables the first and second side regulating plates 303 and 305 to move by operating the side regulation manipulating lever 312 has been described in the above descriptions, the present disclosure is not limited to such configuration. The present disclosure is also applicable to a configuration in which the first and second side regulating plates 303 and 305 are fixed like a sheet feed cassette 300 which corresponds only to a sheet whose widthwise size is constant. Still further, although the present disclosure has been applied to the first side regulating plate 303, it is possible to prevent the deterioration of the storability of the sheet even if the present disclosure is applied to the rear end regulating member 304.
Still further, while the pressing member 301 has been provided with the shaft and the holder member 302 has been provided with the support portion in the above description, the support portion may be provided in the pressing member 301 and the shaft may be provided in the holder member 302. That is, the boss 301c may be provided in one of the pressing member 301 and the holder member 302, and the long hole 302a or the opening portion 302b may be provided in the other one of the pressing member 301 and the holder member 302.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2016-014409, filed Jan. 28, 2016, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-014409 | Jan 2016 | JP | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15404529 | Jan 2017 | US |
| Child | 16018383 | US |
