SHEET PROCESSING APPARATUS

Abstract

A sheet processing apparatus includes a sheet tray, a processing unit configured to process one or more sheets that are placed on the sheet tray, a supporting member that is movable into and out of a conveying path of a sheet to be placed on the sheet tray, and a driving unit configured to move the supporting member into and out of the conveying path of the sheet. The supporting member includes a sheet support section that supports the sheet when the supporting member is moved into the conveying path.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2013-063259, filed Mar. 26, 2013, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a sheet processing apparatus and an image forming apparatus having the same.

BACKGROUND

A sheet processing apparatus is generally attached to an image forming apparatus and carries out a processing of a sheet conveyed from the image forming apparatus. One type of the sheet processing apparatus performs predetermined post-processing such as sorting and stapling of one or more sheets. When a new sheet is conveyed from the image forming apparatus while the sheet processing apparatus is carrying out the post-processing on the one or more sheets, the new sheet needs to be put aside until the post-processing is completed. The sheet processing apparatus employs a large mechanism for putting aside the new sheet until the post-processing on the one or more sheets is completed.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a sheet processing apparatus according to a first embodiment.

FIG. 2 is a cross-sectional view of the sheet processing apparatus according to the first embodiment.

FIG. 3 is a perspective view of a processing tray of the sheet processing apparatus at a first position.

FIG. 4 is a perspective view of the processing tray at a second position.

FIG. 5 is a cross-sectional view of a paddle in the sheet processing apparatus.

FIG. 6 is a perspective view of the paddle shown in FIG. 5.

FIGS. 7-15 each are a cross-sectional view of the sheet processing apparatus carrying out a processing of sheets.

FIG. 16 is a perspective view of a processing tray of the sheet processing apparatus according to a second embodiment.

FIGS. 17A and 17B each are a perspective view of the processing tray according to a modified embodiment.

DETAILED DESCRIPTION

According to an embodiment, a sheet processing apparatus includes a sheet tray, a processing unit configured to process one or more sheets that are placed on the sheet tray, a supporting member that is movable into and out of a conveying path of a sheet to be placed on the sheet tray, and a driving unit configured to move the supporting member into and out of the conveying path of the sheet. The supporting member includes a sheet support section that supports the sheet when the supporting member is moved into the conveying path.

Hereinafter, embodiments for carrying out the present exemplary embodiments will be described with reference to the drawings.

First Embodiment

FIG. 1 is a block diagram of a sheet processing apparatus 200 according to a first embodiment. The sheet processor 200 includes a controller 210, a sensor 230, and a driving unit 235. Each unit of the sheet processor 200 is mutually connected through a bus 300.

The controller 210 includes a processor 212 formed by a Central Processing Unit (CPU) or a Micro Processing Unit (MPU), a memory 214, and a storing device 220. The memory 214 is, for example, a semiconductor memory, and includes a Read Only Memory (ROM) 216 for storing various control programs and a Random Access Memory (RAM) 218 for providing a temporary working space to the processor 212. The storing device 220 is, for example, a hard disk drive and the other semiconductor storing device such as a magnetic storing device, an optical storing device, or a flash memory, or it may be a combination thereof. The controller 210 communicates with a main controller 110 of an image forming device 100. The controller 210 controls the sheet processor 200, based on the information received from the main controller 110 or various programs stored in the ROM 216 or the storing device 220.

The sensor 230 transmits inputs from respective sensors to the controller 210. The driving unit 235 controls respectively corresponding driving mechanisms depending on an instruction from the controller 210.

FIG. 2 is a cross-sectional view of the sheet processing apparatus 200. The sheet processing apparatus 200 performs the post-processing such as stapling and sorting on a sheet. The sheet processing apparatus 200 includes an inlet roller pair 240, a branching unit 242, a first sheet discharge roller pair 244, and a fixed tray 248, each being positioned along a sheet conveying direction. The sheet processing apparatus 200 further includes an outlet roller pair 246, a processing tray 250, a paddle (revolving unit) 270, a stapler 280, and a sheet discharge tray 290, each positioned downstream in the sheet conveying direction with respect to the branching unit 242.

The inlet roller pair 240 receives a sheet on which an image is formed by an image forming unit of the image forming device 100, and conveys the sheet to the branching unit 242. The branching unit 242 guides the sheet to the first sheet discharge roller pair 244 or the outlet roller pair 246, according to an instruction of the controller 210 based on the type of the processing on the input sheet. The first sheet discharge roller pair 244 discharges a sheet to the fixed tray 248. The fixed tray 248 stores a sheet on which an image is formed by, for example, a copy function of the image forming device 100. The outlet roller pair 246 conveys a sheet towards the processing tray 250. The paddle 270 guides a sheet buffered on a supporting member to the processing tray 250.

The processing tray 250 receives sheets conveyed from the outlet roller pair 246. The sheets received by the processing tray 250 are, for example, sorted and stapled. The stapling process is performed by a stapler 280 provided upstream in the sheet conveying direction of the processing tray 250 (hereinafter, referred to as upstream), at a predetermined position of the sheets. The processed sheets are discharged to the sheet discharge tray 290.

The sheet discharge tray 290 stores the sheets discharged from the processing tray 250. The sheet discharge tray 290 in this embodiment is a movable tray which moves vertically depending on a sheet discharge from the processing tray 250 or the loaded amount of sheets. The sheet discharge tray 290 moves vertically when, for example, a sheet detection sensor detects the upper surface of a sheet that is discharged in the sheet discharge tray 290.

Here, the fixed tray 248, the processing tray 250, and the sheet discharge tray 290 are inclined in a way in which the downstream side thereof in the sheet conveying direction (hereinafter, referred to as downstream) is disposed higher.

FIG. 3 is a perspective view of the processing tray 250 in the sheet processing apparatus 200 shown in FIG. 2. The processing tray 250 includes a pair of lateral alignment plates (lateral alignment mechanism) 252, a pair of longitudinal alignment rollers 254, and a pair of rear end stoppers (not shown), in order to align the sheets conveyed from the outlet roller pair 246. The lateral alignment plates 252 are respectively provided on a sheet supporting surface accepting the sheets in the processing tray 250 at the both ends in a width direction orthogonal to the sheet conveying direction (hereinafter, referred to the width direction). The lateral alignment plates 252 align the sheets in the width direction (lateral alignment) by being moved back and forth in the width direction at the same distance by a driving mechanism. The longitudinal alignment rollers 254 are provided in the middle in the width direction and at the rear end portion in the sheet conveying direction (hereinafter, referred to as the rear end portion) in the processing tray 250, with a space therebetween. The rear end stoppers protrudes from the rear end portion of the processing tray 250 in a direction upstream thereof. The longitudinal alignment rollers 254 align the sheets in a longitudinal direction by conveying the sheets on the sheet supporting surface of the processing tray 250 upstream in cooperation with second sheet discharge rollers 258 to the point of the rear end stoppers.

Further, the processing tray 250 includes a pair of second sheet discharge rollers 258, ejectors 260, a belt 262, and a claw 264, in order to discharge the sheets to the sheet discharge tray 290. The second sheet discharge rollers 258 are provided in a front end portion in the sheet conveying direction on the sheet supporting surface (hereinafter, referred to as the front end portion). The second sheet discharge roller 258 of the embodiment includes, for example, four driving rollers. The ejector 260 protrudes upstream in the sheet conveying direction from the middle portion in the rear end of the processing tray 250. In the embodiment, two ejectors 260 are provided between the longitudinal alignment rollers 254 and be driven back and forth in the sheet conveying direction by a driving mechanism. The ejectors 260 convey stapled sheets so as to be caught by the claw 264. The claw 264 is attached to the belt 262. The belt 262 is conveyed around a driving roller and a driven roller (not illustrated) provided in the processing tray 250. The claw 264 moves along the sheet conveying direction, according to the movement of the belt 262 that is caused by the rotation of the driving roller. The claw 264 conveys the sheets passed from the ejectors 260 from the processing tray 250 to the sheet discharge tray 290, in cooperation with the second sheet discharge rollers 258.

The processing tray 250 further includes a supporting member 266 formed in an L-shape in order to “buffer” (i.e., temporarily support) a sheet. The supporting members 266 are respectively provided on the both sides in the width direction outside the movement range of the lateral alignment plates 252 on the processing tray 250. The supporting members 266 are connected to the processing tray 250 and driven between a first position and a second position around a connection portion connected to the processing tray 250 as a rotational axis. The driving mechanism is, for example, a motor or a solenoid. The above-described position of the supporting members 266 is only one example. That is, the supporting members 266 may be arranged at any position as long as it does not interrupt the moving of the lateral alignment plates 252 on the processing tray 250.

The first position of the supporting members 266 is in a state where the supporting members 266 are open upwardly (refer to FIG. 3). Here, the sheets conveyed by the outlet roller pair 246 are conveyed onto the processing tray 250 without being interrupted by the supporting members 266.

FIG. 4 is a perspective view of the supporting member 266 in the second position. The second position is in a state where the supporting members 266 partially cover the top surface of the processing tray 250 on the inner sides of the lateral alignment plates 252 from the both sides. Here, a sheet conveyed by the outlet roller pair 246 falls down on the supporting members 266 but is not on the processing tray 250. The sheet falling down on the supporting members 266 slips to the upstream due to the inclination of the processing tray 250 and the own weight of the sheet. The sheet is buffered in a state where the rear end stopped by a paddle 270 (refer to FIG. 10). In other words, the sheet is guided by the supporting members 266 to the paddle 270. Therefore, the supporting members 266 are preferably arranged upstream of the processing tray 250.

Hereinafter, the operation of the supporting members 266 will be described. When a sheet is conveyed to the processing tray 250, the controller 210 controls the supporting members 266 to be in the first position. In other words, when no processing is performed on a sheet on the processing tray 250, the controller 210 controls the supporting members 266 to be at the first position. On the other hand, when some processing is performed on a sheet on the processing tray 250, the controller 210 controls the supporting members 266 to be at the second position. In other words, when a sheet is buffered, the supporting members 266 are at the second position. The processing in this case means, for example, longitudinal alignment, lateral alignment, stapling, or sheet discharge processing of the stapled sheets to the sheet discharge tray 290. Further, by moving the supporting members 266 from the second position to the first position, the sheet placed on the supporting members 266 falls down to the processing tray 250. The supporting members 266 maybe urged toward one of the first and second positions by an elastic mechanism such as a spring and rotated to the other position by a driving mechanism for driving in one direction.

FIG. 5 is a cross-sectional view of a paddle 270 in the sheet processing apparatus 200 shown in FIG. 2. The paddle 270 pushes a sheet buffered on the supporting members 266 to the processing tray 250. The paddle 270 rotates around a shaft. The paddle 270 includes a receiving portion 272, a tapping portion 274, and a forwarding portion 276. In this embodiment, a plurality of paddles 270 is provided in the width direction of the processing tray 250.

FIG. 6 is a perspective view of the paddles 270 shown in FIGS. 2 and 5. The paddles 270 further include a rear end chuck 278. The rear end chuck 278 rotates coaxially with but independently from a receiving portion 272, a tapping portion 274, and a forwarding portion 276. In the embodiment, the rear end chuck 278 is provided between the two paddles 270 arranged in the middle in the width direction. The rear end chuck 278 and the receiving portion 272 hold a sheet on the receiving portion 272 by clamping the sheet therebetween. In short, a sheet is held by the two receiving portions 272 arranged in the middle in the width direction and the rear end chuck 278.

The respective members of the paddle 270 perform the following operations. The receiving portion 272 supports the rear end portion of a sheet in a state where the sheet is placed on the supporting members 266 (shown in FIG. 10). The tapping portion 274 pushes the sheet downward when the sheet on the supporting members 266 falls down on the processing tray 250 (shown in FIG. 14). The forwarding portion 276 helps the sheet falling down on the processing tray 250 conveyed to the rear end stoppers by the longitudinal alignment rollers 254 (shown in FIG. 15).

Hereinafter, referring to FIGS. 7 to 16, the processing of the sheet processing apparatus 200 and the operations of the processing tray 250 and the paddles 270 according to the embodiment will be described with an example where two bundles of two stapled sheets are finished.

At first, a request to execute the post-processing such as stapling on sheets is input, for example, to the image forming device 100 connected with the sheet processor 200 and the request is transferred to the controller 210 of the sheet processor 200. Then, a sheet on which an image is formed is discharged from the image forming device 100 and received by the inlet roller pair 240 of the sheet processor 200 shown in FIG. 2. When there is no post-processing request, the branching unit 242 discharges the sheet through the first sheet discharge roller pair 244 to the fixed tray 248. On the other hand, when there is a post-processing request, for example, stapling request, the branching unit 242 guides a first sheet P1 conveyed from the inlet roller pair 240 to the outlet roller pair 246. The outlet roller pair 246 conveys the sheet P1 towards the processing tray 250. At this point, the supporting members 266 are moved by the driving mechanism to the first position as an initial position, and the sheet P1 falls down on the sheet supporting surface of the processing tray (shown in FIG. 7). The controller 210 performs processing for the lateral alignment and the longitudinal alignment on the sheet P1 placed on the processing tray 250, according to the lateral alignment plates 252, the longitudinal alignment rollers 254, and the second sheet discharge rollers 258. A second sheet P2 is conveyed to the processing tray 250, according to the same operation as the sheet P1 (shown in FIG. 8). When the longitudinal alignment and the lateral alignment on the sheet P2 are completed, the controller 210 performs the stapling processing on a sheet bundle Pa of the sheet P1 and the sheet P2.

During the stapling processing for the sheet bundle Pa, a third sheet P3 is conveyed by the outlet roller pair 246 (shown in FIG. 9). Here, the supporting members 266 are moved to the second position. As the sheet bundle Pa is being processed, the third sheet P3 is buffered on the supporting members 266 that are moved to the second position. The sheet P3 is conveyed downstream while the front end portion of the sheet P3 is sliding on the supporting members 266. When the rear end of the sheet P3 is separated from the outlet roller pair 246, the sheet P3 slides in the upstream direction due to the inclination of the processing tray 250 and the weight of the sheet itself. When the rear end of the sheet P3 reaches the paddles 270, the sheet P3 is buffered in that position (refer to FIG. 10). When the sheet P3 is in a state of buffer, the rear end chuck 278 holds the sheet P3. For example, the rear end chuck 278 holds the sheet when a detection sensor detects a sheet being on the supporting members 266. Further, the controller 210 similarly causes a fourth sheet P4 to be buffered on the supporting members 266 (refer to FIG. 11). The rear end chuck 278 is temporarily released when the sheet P4 reaches the paddle 270. When the sheet P4 is placed on the top surface of the sheet P3, the rear end chuck 278 holds a sheet bundle Pb of the two (P3 and P4) (refer to FIG. 12).

When the stapling processing is performed on the first sheet bundle Pa, the sheet bundle Pa is discharged from the processing tray 250 to the sheet discharge tray 290, according to the operations of the ejector 260, the claw 264 attached to the belt 262, the longitudinal alignment rollers 254, and the second sheet discharge rollers 258 (refer to FIG. 13). At this point, for example, even when the front end portions of the sheet P2 and the sheet P3 are in touch with each other, the sheet bundle Pb held by the rear end chuck 278 will not follow the first sheet bundle Pa. Next, after the discharge of the sheet bundle Pais completed, the controller 210 controls the driving unit 235 to drive the driving mechanism, so as to move the supporting members 266 from the second position to the first position. In short, the supporting members 266 perform the opening operation. When the supporting members 266 are opened, at the same time, the paddles 270 simultaneously rotate to drop the sheet bundle Pb on the processing tray 250 (refer to FIG. 14). According to the operation of the supporting members 266 and the paddles 270, the sheet bundle Pb on the supporting members 266 drops on the processing tray 250 (refer to FIG. 15). Since the sheet discharge operation of the sheet bundle Pb is the same as the operation of the above-mentioned sheet bundle Pa, the description is omitted.

According to the first embodiment, by providing the supporting members that supports sheets above the processing tray, a mechanism for buffering a sheet can be downsized. By buffering a sheet following a sheet that is subject to a processing, more time can be secured for the processing. Further, as the sheet conveying time and the post-processing time of a sheet are overlapped, the productivity of the sheet processing apparatus does not need to be compromised. Further, even when the front end portions of the sheet bundle on the processing tray and the sheet bundle buffered on the supporting members are in touch with each other, the buffered sheet bundle is prevented from going out when the sheet bundle on the processing tray is discharged as the rear end chuck holds the buffered sheet bundle.

Second Embodiment

A sheet processor according to the second embodiment is different from the sheet processor 200 according to the first embodiment in that supporting members 266a are provided on the upper portions of the lateral alignment plates 252.

FIG. 16 is a perspective view of the processing tray 250 according to the second embodiment. The supporting members 266a according to the embodiment are respectively provided on the upper portions of the lateral alignment plates 252. Specifically, in accordance with the operation of the lateral alignment plates 252, the supporting members 266a are moved in the width direction. The supporting member 266a is rotatable around a connection portion with the lateral alignment plate 252 as a shaft. The supporting member 266a is driven by a driving mechanism such as a motor and a solenoid, similarly to the first embodiment.

The lateral alignment plates 252 slide in the width direction during the sorting processing. When the supporting member 266a is short in the width direction, a buffered sheet may drop down during the sliding of the plates 252. Therefore, it is preferable that the length in the width direction of the supporting member 266a is formed longer at least than the sliding distance of the lateral alignment plate 252.

According to the second embodiment, the same effect as the first embodiment can be achieved. Further, since the supporting members are integrally formed with the lateral alignment plates, any sheet may be buffered regardless of the size of a sheet.

According to at least one embodiment described above, as the supporting members that support a sheet are provided above the processing tray, it possible to downsize a mechanism for buffering the sheet. By buffering a sheet that follows a sheet to be processed, more time may be secured for the processing. Further, as the sheet conveying time and the sheet post-processing time are overlapped, the productivity of the sheet processor does not need to be compromised.

The disclosure is not restricted to the above embodiments, and various modifications are possible. FIGS. 17A and 17B are a modified example of the supporting member 266. The supporting member may be formed in a shape of extending in a downstream direction as illustrated in FIGS. 17A and 17B. As the operation of the supporting member of this modified example is the same as that of the second embodiment, the description is omitted.

Further, the number of the sheets to be buffered is not limited to two as in the above embodiment. It may be properly changed depending on the sheet conveying speed and the processing time.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the embodiments described herein maybe made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

Claims

1. A sheet processing apparatus comprising:

a sheet tray;

a processing unit configured to process one or more sheets that are placed on the sheet tray;

a supporting member that is movable into and out of a conveying path of a sheet to be placed on the sheet tray, the supporting member including a sheet support section that supports the sheet when the supporting member is moved into the conveying path; and

a driving unit configured to move the supporting member into and out of the conveying path of the sheet.

2. The sheet processing apparatus according to claim 1, further comprising:

a holding unit configured to hold a rear end portion of the sheet placed on the sheet support section.

3. The sheet processing apparatus according to claim 1, wherein

the driving unit moves the supporting member out of the conveying path when the processing unit is not processing any sheets, and into the conveying path when the processing unit is processing sheets.

4. The sheet processing apparatus according to claim 1, wherein

the processing unit includes a moving mechanism configured to move in a width direction orthogonal to a sheet conveying direction such that the sheets placed on the sheet tray is moved in the width direction in accordance with the moving of the moving mechanism.

5. The sheet processing apparatus according to claim 4, wherein

the supporting member is disposed on the moving mechanism.

6. The sheet processing apparatus according to claim 4, wherein

the supporting member is disposed at a position such that the moving mechanism does not interfere with the supporting member when the moving mechanism moves.

7. The sheet processing apparatus according to claim 1, wherein

the supporting member is disposed at a position upstream in a sheet conveying direction with respect to the sheet tray.

8. A method for processing a sheet, comprising:

conveying sheets through a sheet conveying path to a sheet tray as a supporting member having a sheet support section is moved into and out of the sheet conveying path; and

processing one or more of the sheets that are placed on the sheet tray,

wherein the sheet support section temporarily holds a conveyed sheet thereon when the processing of the one or more of the sheets placed on the sheet tray is being carried out.

9. The method according to claim 8, wherein the conveyed sheet temporarily held by the sheet support section is released by the sheet support section when the processing of the one or more of the sheets placed on the sheet tray has completed.

10. The method according to claim 9, further comprising:

moving the supporting member into the sheet conveying path when the processing of the one or more of the sheets placed on the sheet tray is being carried out.

11. The method according to claim 10, further comprising:

moving the supporting member out of the sheet conveying path when the processing of the one or more of the sheets placed on the sheet tray has completed.

12. The method according to claim 8, further comprising:

holding a rear end portion of the sheet placed on the sheet support section.

13. The method according to claim 8, further comprising:

prior to said processing, moving the sheets placed on the sheet tray in a width direction orthogonal to a sheet conveying direction.

14. An image forming apparatus comprising:

an image forming unit configured to form an image on sheets; and

a sheet processing apparatus that includes a sheet tray, a processing unit configured to process one or more sheets that are placed on the sheet tray, a supporting member that is movable into and out of a conveying path of a sheet to be placed on the sheet tray, the supporting member including a sheet support section that supports the sheet when the supporting member is moved into the conveying path, and a driving unit configured to move the supporting member into and out of the conveying path of the sheet.

15. The image forming apparatus according to claim 14, wherein the sheet processing apparatus further includes:

a holding unit configured to hold a rear end portion of the sheet placed on the sheet support section.

16. The image forming apparatus according to claim 14, wherein

the driving unit moves the supporting member out of the conveying path when the processing unit is not processing any sheets, and into the conveying path when the processing unit is processing sheets.

17. The image forming apparatus according to claim 14, wherein

the processing unit includes a moving mechanism configured to move in a width direction orthogonal to a sheet conveying direction such that the sheets placed on the sheet tray is moved in the width direction in accordance with the moving of the moving mechanism.

18. The image forming apparatus according to claim 17, wherein

the supporting member is disposed on the moving mechanism.

19. The image forming apparatus according to claim 17, wherein

the supporting member is disposed at a position such that the moving mechanism does not interfere with the supporting member when the moving mechanism moves.

20. The image forming apparatus according to claim 14, wherein

the supporting member is disposed at a position upstream in a sheet conveying direction with respect to the sheet tray.