1. Field of the Invention
The present invention relates to a sheet storage apparatus, and an image forming apparatus including the sheet storage apparatus.
2. Description of the Related Art
Conventionally, there has been an image forming apparatus such as a copying machine that can temporarily store a sheet on which an image has been formed (hereinafter, referred to as “image-formed sheet”) in a sheet storage unit, and discharges the stored sheet so that a user can receive the sheet by an operation (e.g., button operation or identification (ID) authentication).
Japanese Patent Application Laid-Open No. 2013-220905 discusses a sheet storage apparatus capable of relieving a user of time and labor of searching for and receiving the user's own sheet (job) from a discharge tray on which sheets (jobs) printed by a plurality of users are stacked (in mixed manner). In other words, the sheet storage apparatus discussed in Japanese Patent Application Laid-Open No. 2013-220905 is advantageous in that the user can easily receive the user's own printed job.
In a sheet storage apparatus discussed in Japanese Patent Application Laid-Open No. 2013-220905, to restrain enlargement of an image forming apparatus while securing a sufficient storage area in a sheet storage unit, reduction in size in a height direction of the sheet storage unit is necessary.
The present invention is directed to a sheet storage apparatus and an image forming apparatus capable of reducing the size of the sheet storage apparatus including a sheet storage unit in a height direction.
According to an aspect of the present invention, a sheet storage apparatus for storing a sheet conveyed by a sheet conveyance unit includes a plurality of sheet storage units vertically stacked at a plurality of stages, a lower guide disposed in each of the plurality of sheet storage units and configured to guide a lower surface of the conveyed sheet, an upper guide disposed in each of the plurality of sheet storage units and configured to guide an upper surface of the conveyed sheet, a rotary member disposed in each of the plurality of sheet storage units and in one of the lower guide and the upper guide, and configured to be rotatable by contacting a sheet stored in a sheet storage unit from a home position around a rotational axis extending in a direction orthogonal to a sheet conveying direction, a sensor disposed in each of the plurality of sheet storage units and configured to output a signal according to a position of the rotary member, and a control unit configured to detect presence of a sheet in the sheet storage unit according to an output of the sensor, wherein at the home position, at least a part of the rotary member overlaps a rotational axis of a rotary member of an adjacent sheet storage unit in a vertical direction
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.
In
A stacking unit 124, which is disposed on an upper surface of the apparatus main body, stacks the sheet on which the image has been formed by the image forming unit 101. Sheet storage units 201, 202, and 203 configured to store the sheet on which the image has been formed by the image forming unit 101 are arranged between the image forming unit 101 and the stacking unit 124.
The image forming unit 101 includes a photosensitive drum 111 that can be rotated clockwise in
The sheet feeding unit 102 includes a feeding cassette 105 for storing a plurality of sheets S to be supplied for image formation in a stacked state, a feeding roller 107, a conveyance guide 109, and a registration roller 110. The fixing unit 103 includes a fixing roller 116, and a pressure roller 117 abutted on the fixing roller 116 from below. A conveyance roller 118 is disposed on the downstream side of the fixing unit 103.
A reconveyance path 126 of the sheet S is disposed between the image forming unit 101, the fixing unit 103, and the feeding cassette 105. The reconveyance path 126 is used for forming images on both front and rear surfaces of the sheet S.
When images are formed on both surfaces of the sheet, the sheet having a toner image formed on one surface (front surface) is conveyed toward a reversing roller 123. A conveyance roller 121 and the reversing roller 123, which are provided to be rotatable normally and reversely, convey the sheet to the stacking unit 124 when rotated normally, and convey the sheet again to the image forming unit 101 when rotated reversely. After a trailing end of the sheet has exited from a branch portion 127, the conveyance roller 121 and the reversing roller 123 are rotated reversely to switch back the sheet. Then, the sheet passes through the reconveyance path 126 to be conveyed to the image forming unit 101.
In the image forming apparatus according to the present exemplary embodiment, a plurality of stages of sheet storage units is vertically stacked, which are a first sheet storage unit 201, a second sheet storage unit 202, and a third sheet storage unit 203 in this order from the top.
A conveyance roller 204 serves as a sheet conveyance unit configured to convey the image-formed sheet to the first sheet storage unit 201. Similarly, a conveyance roller 205 conveys the sheet to the second sheet storage unit 202, and a conveyance roller 206 conveys the sheet to the third sheet storage unit 203.
A first conveyance path switching member 120 can be switched between a first position indicated by a solid line in
When the sheet is discharged to the staking unit 124, the first conveyance path switching member 120 is switched to the position indicated by the broken line. The sheet is conveyed along a discharging guide 122 by the conveyance roller 121, and discharged to the stacking unit 124 by the reversing roller 123. As illustrated in
A full-stack detection sensor lever 125 detects a full-stack state of sheets stacked on the stacking unit 124. When the full-stack detection sensor lever 125 detects a full-stack state of sheets, a control unit performs control not to form any images on a sheet until the sheets are removed from the stacking unit 124.
When the sheet is conveyed to the sheet storage unit, the first conveyance path switching member 120 is switched to the position indicated by the solid line. The sheet is conveyed through a conveyance path 128 to a sheet storage apparatus 200.
A second switching member 211 and a third switching member 212 are provided for switching a path through which the sheet is conveyed. Each of the second switching member 211 and the third switching member 212 is configured to be switched between a position indicated by the solid line and a position indicated by the broken line illustrated in
When the sheet S is conveyed to the first sheet storage unit 201, the second switching member 211 and the third switching member 212 are respectively switched to the positions indicated by the solid line illustrated in
When the sheet S is conveyed to the second sheet storage unit 202, the second switching member 211 and the third switching member 212 are respectively switched to the position indicated by the solid line and the position indicated by the broken line illustrated in
When the sheet S is conveyed to the third sheet storage unit 203, the second switching member 211 is switched to the position indicated by the broken line illustrated in
Next, a configuration of each sheet storage unit will be described in detail. In the image forming apparatus according to the present exemplary embodiment, the plurality of stages of sheet storage units is vertically stacked. The sheet storage units are similar in configuration, and thus the configuration of the first sheet storage unit 201 will be mainly described.
The sheet conveyed to the first sheet storage unit 201 by the conveyance roller 204 is temporarily stacked on a stacking surface 231 to be stored. Whether a sheet is stacked on the stacking surface 231 is detected by a sheet presence detection unit. The sheet presence detection unit includes a sheet presence detection flag 251 and a sensor. A configuration of the sheet presence detection unit will be described in detail below. An extrusion unit 233 extrudes a conveying-direction upstream end (trailing end) of the stored sheet to expose a part of a conveying-direction downstream end (leading end) of the stored sheet to outside of the apparatus main body 100 from a discharge opening 234.
A state where the sheet S′ has thus been extruded to the discharge opening by the sheet extrusion unit 233 is illustrated as a state of the sheet storage unit 203 in
The image forming apparatus CPU 503 controls printing according to the printing conditions received from the video controller 502. In addition, the image forming apparatus CPU 503 detects an error such as jamming at the image forming apparatus 100 based on information from a jam detection sensor 504 to notify the video controller 502 of the detection result. The image forming apparatus CPU 503 controls a sheet conveyance mechanism 506 to perform a sheet feeding or discharging operation, and controls the image forming unit 101 and the fixing unit 103 to perform an image forming operation and a fixing operation. The image forming apparatus CPU 503 controls a sheet storage unit control mechanism 507 including the conveyance rollers 204 to 206 to convey the image-formed sheet to the sheet storage unit. The image forming apparatus CPU 503 controls, according to an instruction from the video controller 502, the sheet extrusion unit 233 to control discharging of the sheet stored in the sheet storage unit by using information of a connected sheet discharge sensor 505.
Referring back to
When the user selects storing the sheet in the sheet storage unit, the control unit 501 searches, based on a detection result of the sheet presence detection unit disposed in each sheet storage unit, for a sheet storage unit where no sheet has been stored to determine a sheet conveyance destination.
For example, when the sheet conveyance destination is determined to be the first sheet storage unit 201, each of the switching members is switched as described above to convey the sheet onto the stacking surface 231 of the first sheet storage unit 201.
Since the control unit 501 has information about whose job has been stored in which sheet storage unit, the control unit 501 can designate a sheet storage unit that has already stored the user's sheet as a storage destination if a job is the same user's. The user is not required to designate which sheet storage unit stores the user's job. The sheet is automatically stored in an empty sheet storage unit each time the user's sheet is discharged.
The sheet stored in each sheet storage unit cannot be taken out from the outside of the apparatus main body. The sheet stored in the sheet storage unit is extruded by the extrusion unit according to a user's discharging instruction, and a discharging operation is started. The discharging instruction is issued by pressing a discharging operation start button at the operation display unit disposed in the apparatus main body, ID card authentication, or issuance of a discharging operation start command on the external device connected to the image forming apparatus. A specific method for issuing the discharging operation start command issued from the operation display unit is as follows. For example, a name or a personal ID number of a user having the user's job stored in the sheet storage unit is displayed on the operation display unit 240 disposed in the apparatus main body 100, and a discharging instruction can be issued by operating a portion corresponding to the user. When user authentication is performed by using an ID card, the ID card authentication unit 241 is attached to the apparatus main body. Then, a sheet discharging instruction can be issued by obtaining ID information therefrom.
Upon receiving the sheet discharging instruction, the video controller 502 issues the sheet discharging instruction to the image forming apparatus CPU 503. The image forming apparatus CPU 503 controls the actuator to move the extrusion unit 233 from the stacking position to the extruding position.
In this case, information about the user who has instructed printing of the sheet stored in the sheet storage unit has been stored in a storage unit. In other words, since the information about whose job has been stored in which sheet storage unit has been stored in the storage unit, the user is not required to recognize which sheet storage unit has stored the user's job. The user can receive the user's job by issuing the sheet discharging instruction.
Near the discharge openings 234 to 236, a sheet discharge sensor (not illustrated) is disposed as a detection unit configured to detect removal of a sheet bundle B by the user. After the removal of the sheet bundle B has been detected by the sheet discharge sensor, the extrusion unit 233 moves from the extruding position to the stacking position.
Each of the sheet storage units 201 to 203 includes a sheet presence detection unit configured to detect whether any sheet has been stacked in the sheet storage unit. The sheet presence detection units respectively include sheet presence detection flags (rotary members or moving members) 251 to 253 rotatable from home positions by contacting the sheets stored in the sheet storage units 201 to 203, and photosensors 281 to 283 configured to output signals according to positions of the sheet presence detection flags. The control unit 501 deletes sheet storage information by detecting that there is no sheet stacked in the sheet storage units 201 to 203 according to the outputs from the photosensors 281 to 283. Thus, the sheet storage unit can store a new sheet (another job) again.
Next, a configuration of the sheet presence detection unit will be described in detail.
The sheet presence detection flags 252 and 253 are similar in configuration to the sheet presence detection flag 251, and thus the sheet presence detection flag 251 will be mainly described below. The sheet presence detection flag 251 made of one wire material as illustrated in
In the present exemplary embodiment, the flag portion 251b has a triangular shape (bent portion) formed by bending the wire material. The sheet presence detection flag 251 is held by a first support member 261 and a second support member 262 in a vertical direction and the sheet conveying direction. Since the rotational axis 251a of the sheet presence detection flag 251 is sandwiched between the first support member 261 and the second support member 262 to be included therebetween, the sheet is not stuck on the rotational axis 251a during conveying.
The first support member 261 includes a notch 261a that can store the flag portion 251b. Similarly, the second support member 262 includes a notch 262a.
As illustrated in
The sheet presence detection flag 251 receives a force applied by self-weight of the sheet presence detection flag 251 and self-weight of the sensor light shielding unit 271 to rotate in a clockwise direction in
Next, a most characteristic configuration of the present exemplary embodiment will be described with reference to
The sheet presence detection flag 251 has been mainly described above. The sheet presence detection flags 252 and 253 and the respective flag portions 252b and 253b are similar in configuration to the sheet presence detection flag 251 and the flag portion 251b.
Finally, an operation of the sheet presence detection unit will be described. In
The sheet storage unit 202 is illustrated as in a state where a sheet has been stored therein. The sheet presence detection flag 252 is riding on the stored sheet. At this time, the photosensor 282 that detects a state of the sheet presence detection flag 252 is in a light transmitting state. In other words, the control unit detects that there is a sheet in the sheet storage unit 202.
The sheet storage unit 203 is illustrated as in a state where the leading end of the sheet is being discharged from the discharge opening. In the state illustrated in
As described above, according to the present exemplary embodiment, the sheet storage apparatus that includes the plurality of stages of vertically stacked sheet storage units can be reduced in size in the height direction.
More specifically, the vertex of the flag portion 251b overlaps the support member 263 serving also as a lower guide to guide a lower surface of the sheet stored in the sheet storage unit 201, and the rotational axis 252a of the adjacent sheet presence detection flag. With this configuration, the first support member 261 and the second support member 262 can be thinned as much as possible, while preventing the sheet from slipping therethrough. Thus, the sheet storage apparatus can be miniaturized while a sheet storage space can be secured in the height direction. The support member 262 also functions as an upper guide to guide the upper surface of the sheet stored in the sheet storage unit 201.
Further, adopting the configuration of the present exemplary embodiment enables a positional relationship between the sheet conveyance unit and the sheet presence detection flag to be similar among the sheet storage units. This provides an effect of communalizing the components of each storage unit. Examples of components to be shared include the sheet conveyance unit, the sheet presence detection flag, the sensor light shielding unit, the support member, and the sheet discharging unit.
Further, according to the present exemplary embodiment, the strength of the sheet presence detection flag 251 made of the wire material can be increased by sandwiching the sheet presence detection flag 251 between the support member 262 and the support member 261. Since the sheet presence detection flag 251 is not subject to application of strong strength thereto, it can be made of a wire material. However, the present invention should not be limited to the formation of the sheet presence detection flag 251 by the wire material. The sheet presence detection flag can be made of a molded component or the like.
Further, tinning of the sheet storage apparatus is achieved by disposing the photosensor and the sensor light shielding unit outside (outside sheet storage area) of the sheet conveyance path in the width direction.
If the sheet storage apparatus can be thinned, the number of sheet storage units arranged in the image forming apparatus main body can be increased while suppressing the height of the entire apparatus.
Hereinafter, a second exemplary embodiment of the present invention will be described with reference to the drawings. In the first exemplary embodiment, the configuration where the shape of the flag portion 251b of the sheet presence detection flag 251 is triangular has been described. However, in the present exemplary embodiment, the shape of the flag portion 251b is not limited to the triangular shape. Flag portions with other shapes can provide the same effects as those of the first exemplary embodiment. Basically, as long as the shape of the flag portion 251b is tapered more away from the rotational axis 251a of the sheet presence detection flag, the same effects as those of the first exemplary embodiment can be provided.
Hereinafter, a third exemplary embodiment of the present invention will be described with reference to the drawings. In the first exemplary embodiment and the second exemplary embodiment, the configuration where the shapes of the flag portions of the sheet presence detection flags included in the sheet storage units are similar has been described. However, the present invention is not limited to this configuration. As long as flag portions of sheet presence detection flags have shapes similar to those illustrated in
As illustrated in
According to the first to third exemplary embodiments described above, at least a part of the rotary member overlaps, at the home position (contact position), the rotational axis of the rotary member of the adjacent sheet storage unit in the vertical direction. Thus, the sheet storage unit can be designed to be thin, and the sheet storage apparatus can be miniaturized in the height direction. Further, the components can be communalized among the sheet storage units.
Further, according to the first to third exemplary embodiments, a rotational supporting point of the sheet presence detection flag is arranged in the upper guide (support member) of each sheet storage unit. This is for a reason below. Since the self-weight of the sheet presence detection flag is applied in a direction for holding the flag itself at the home position by arranging the rotational supporting point of the sheet presence detection flag on the upper side, a spring force for pressing the sheet presence detection flag can be set low. As described above in the exemplary embodiments, no spring may be necessary depending on a design of the apparatus.
However, in the present invention, the rotational supporting point of each sheet presence detection flag may be arranged in the lower guide of each sheet storage unit. In other words, the sheet presence detection flag as the rotary member may be disposed in one of the lower and upper guides, and formed to be tapered toward the other side.
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. 2014-083186 filed Apr. 14, 2014, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2014-083186 | Apr 2014 | JP | national |