Patent Grant
9010745
1. Field of the Invention
The present invention relates to a sheet processing apparatus that has a function of aligning sheets stacked on a receiving tray, a method of controlling the same, and a storage medium.
2. Description of the Related Art
For sheet stackers that stack printed sheets discharged from a printing apparatus on a tray, there has been demand for the ability to align the sheets on the tray with a high degree of accuracy. Japanese Patent Laid-Open No. 2006-206331 suggests a technique to align sheets stacked on a receiving tray. According to this technique, alignment members are provided on the receiving tray, and the positions of edge surfaces of the sheets parallel to a sheet discharge direction are aligned by the alignment members coming into and out of contact with the edge surfaces of the sheets.
Now, assume the case where, as shown in
There is also a possibility that the removed toner is attached to and stains the bottom surface of the alignment plate A, and the attached toner stains other sheets when the bottom surface of the alignment plate A comes into contact with other sheets. Upon printing sheets that have a different width from sheets that are already printed and stacked, the printing may be interrupted first to allow a user to remove the sheets that are already printed and stacked from the receiving tray, and then the printing may be resumed for the sheets that have a different width. Although this method does not give rise to the aforementioned problem, it is still problematic in that it reduces the productivity of printing.
An aspect of the present invention is to eliminate the above-mentioned problems with the conventional technology.
A feature of the present invention is to provide a technique to, even when a sheet that has a different width from a stacked sheet is to be stacked on the stacked sheets, align sheets without interrupting a print process and without staining the stacked sheet.
According to an aspect of the present invention, there is provided a sheet processing apparatus comprising: a discharge control unit configured to control to discharge a sheet on a stacking unit; an alignment unit configured to align sheets stacked on the stacking unit by causing a first alignment member and a second alignment member to come into contact with edges of a sheet stacked on the stacking unit in a sheet width direction; and a control unit configured to perform control to, in a case that a second sheet that is different from a first sheet stacked on the stacking unit is to be stacked on the first sheet and aligned by the alignment unit, separate between the first sheet and the second sheet by discharging a partition sheet onto the first sheet stacked on the stacking unit.
According to an aspect of the present invention, there is provided a method of controlling a sheet processing apparatus, comprising: controlling to discharge a sheet on a stacking unit; aligning sheets stacked on the stacking unit by causing a first alignment member and a second alignment member to come into contact with edges of a sheet stacked on the stacking unit in a sheet width direction; and performing control to, in a case that a second sheet that is different from a first sheet stacked on the stacking unit is to be stacked on the first sheet and aligned, discharge a partition sheet onto the first sheet stacked on the stacking unit.
According to an aspect of the present invention, there is provided a sheet processing apparatus comprising: a discharge control unit to control to discharge a sheet on a stacking unit; an alignment unit configured to align sheets stacked on the stacking unit by causing a first alignment member and a second alignment member to come into contact with edges of a sheet stacked on the stacking unit in a sheet width direction; and a control unit configured to perform control to the alignment unit to align sheets stacked on the stacking unit even if a second sheet that is different from a first sheet stacked on the stacking unit is to be stacked on the first sheet.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
Embodiments of the present invention will be described hereinafter in detail, with reference to the accompanying drawings. It is to be understood that the following embodiments are not intended to limit the claims of the present invention, and that not all of the combinations of the aspects that are described according to the following embodiments are necessarily required with respect to the means to solve the problems according to the present invention. It should be noted that a sheet processing apparatus according to the present invention may be included in a later-described image forming apparatus, may be included in a sheet stacker, or may constitute an image forming apparatus or a sheet stacker.
This image forming system includes an image forming apparatus 10 and a finisher 500 that serves as a sheet stacker. The image forming apparatus 10 includes an image reader 200 that reads an image from an original, and a printer 350 that forms (prints) the read image on a sheet.
A document feeder 100 feeds originals set on an original tray 101 one by one in order starting from the top original, conveys the originals along a curved path and past a predetermined reading position on a glass platen 102, then discharges the originals onto a discharge tray 112. Note that the originals are set on the original tray 101 with their front sides up. At this time, a scanner unit 104 is fixed at the predetermined reading position. When an original passes the reading position, an image of the original is read by the scanner unit 104. When the original passes the reading position, the original is irradiated with light from a lamp 103 in the scanner unit 104, and reflected light from the original is directed to a lens 108 via mirrors 105, 106 and 107. Light that has passed through this lens 108 is focused on an imaging surface of an image sensor 109, converted into image data, and output. The image data output from the image sensor 109 is input as a video signal to an exposure unit 110 in the printer 350.
The exposure unit 110 in the printer 350 outputs laser light that has been modulated based on a video signal input from the image reader 200. A photosensitive drum 111 is irradiated with and scanned by this laser light using a polygonal mirror 119. An electrostatic latent image corresponding to the laser light that has scanned the photosensitive drum 111 is formed on the photosensitive drum 111. This electrostatic latent image on the photosensitive drum 111 turns into a visible image by being developed using a developing agent fed from a developer 113. In the following embodiments, a 1D-type image forming apparatus 10 including one developer 113 and one photosensitive drum 111 is described as an example. However, the present invention is not limited in this way, and the image forming apparatus 10 may alternatively include developers and photosensitive drums corresponding to C (cyan), M (magenta), Y (yellow) and K (black).
Sheets used in the printing are picked up one by one from a sheet feeding tray 114 or 115, which is provided in the printer 350, by rotation of a pickup roller 127 or 128. The sheet thus picked up is conveyed to the position of registration rollers 126 by rotation of sheet feeding rollers 129 or 130. Although
The following describes a configuration of a controller that controls the entirety of the image forming system and a block diagram of the entirety of the system according to some embodiments with reference to
The controller includes a CPU circuit unit 900, and the CPU circuit unit 900 includes a CPU 901, a ROM 902, and a memory unit 903. The memory unit 903 is constituted by a RAM or an HDD. The CPU 901 controls the entirety of the present image forming system, and is connected to the ROM 902 in which control programs are written and to the memory unit 903 for temporarily storing various types of data via an address bus and a data bus (not shown in the figures). The CPU 901 also performs overall control of controllers 911, 921, 922, 931, 941 and 951, as well as an external interface 904, in accordance with the control programs stored in the ROM 902. The memory unit 903 temporarily holds control data and is used as a working area for calculation processing associated with control.
A document feed controller 911 controls driving of the document feeder 100 based on instructions from the CPU circuit unit 900. An image reader controller 921 controls driving of the above-described scanner unit 104, image sensor 109, and the like, and transfers an image signal output from the image sensor 109 to an image signal controller 922. The image signal controller 922 converts an analog image signal from the image sensor 109 into a digital signal, applies various types of processing to the digital signal, converts the digital signal into a video signal, and outputs the video signal to a printer controller 931. The image signal controller 922 also converts a digital image signal input from a computer 905 via the external I/F 904 into a video signal by applying various types of processing to the digital image signal, and outputs the video signal to the printer controller 931. The operations of processing executed by this image signal controller 922 are controlled by the CPU circuit unit 900. The printer controller 931 controls the exposure unit 110 and the printer 350 based on the input video signal so as to form images, convey sheets, and the like. A finisher controller 951 is mounted on the finisher 500, and controls driving of the finisher 500 by exchanging information with the CPU circuit unit 900. The details of this control will be described later. A console unit controller 941 exchanges information with a console unit 400 shown in
For example, a start key 402, a stop key 403, numeric keys 404 to 413, a clear key 415, and a reset key 416 are arranged on the console unit 400. The start key 402 is used to start the image forming operations. The stop key 403 is used to interrupt the image forming operations. The numeric keys 404 to 413 are used to, for example, enter numbers. A display unit 420 is also arranged on the console unit 400. A touchscreen is formed on the upper part of the display unit 420. Software keys can be displayed on a screen of the display unit 420.
This image forming apparatus 10 has various process modes as post-process modes, including no sort, sort, shift-sort, staple-sort, and the like. The settings and the like for these process modes are input from the console unit 400. For example, a post-process mode is set as follows. If a “Finishing” software key 417 is selected on a default screen shown in
The following describes a configuration of the finisher 500 with reference to
First, a description is provided with reference to
The finisher 500 receives sheets discharged from the image forming apparatus 10 in order, and executes post-processes such as a process for aligning the plurality of received sheets in a bundle, and a staple process for binding the trailing edges of the bundle of sheets using a stapler. The finisher 500 receives a sheet discharged from the image forming apparatus 10 along a conveyance path 520 using a pair of conveyance rollers 511. The sheet that has been received using the pair of conveyance rollers 511 is conveyed via pairs of conveyance rollers 512, 513 and 514. Sheet sensors 570, 571, 572 and 573 are provided on the conveyance path 520 to detect passing of the sheet. The pair of conveyance rollers 512 is provided in a shift unit 580 together with the conveyance sensor 571.
The shift unit 580 can move the sheet in a sheet width direction orthogonal to a sheet conveyance direction using a later-described shift motor M5 (
When the finisher 500 detects that a sheet has passed the shift unit 580 based on the input from the sheet sensor 571, the finisher 500 drives the shift motor M5 (
A flapper 541, which switches between an upper discharge path 521 and a lower discharge path 522, is arranged between the pair of conveyance rollers 514 and the pair of conveyance rollers 515. The flapper 541 is driven by the later-described solenoid SL1. When the flapper 541 switches to the upper discharge path 521, a sheet is directed to the upper discharge path 521 by the pair of conveyance rollers 514 that is driven and rotated by a buffer motor M2 (
Furthermore, an alignment plate 711a (first alignment member) and an alignment plate 711b (second alignment member) are arranged on the receiving tray 701 as shown in
The receiving trays 700 and 701 can be raised and lowered by later-described tray elevator motors M15 and M16 (
A description is now given of a configuration of the finisher controller 951 that controls driving of the finisher 500 with reference to
The finisher controller 951 includes a CPU 952, a ROM 953, a RAM 954, and the like. The finisher controller 951 controls driving of the finisher 500 by communicating with the CPU circuit unit 900, exchanging data with the CPU circuit unit 900, and executing various types of programs stored in the ROM 953. The data exchange denotes, for example, transmission/reception of commands, exchange of job information, and notification of sheet transfer. The following describes various types of inputs and outputs of the finisher 500.
In order to convey sheets, the finisher 500 includes a motor M1 that drives and rotates the pairs of conveyance rollers 511 to 513, a buffer motor M2, a discharge motor M3, a shift motor M5, solenoids SL1 and SL2, and sheet sensors 570 to 576. The finisher 500 also includes, as means to drive various types of members in the process tray 630 (
The following describes a flow of sheets during a sort mode with reference to
If the user selects the “Finishing” software key 417 on the default screen shown in
In order to offset a bundle of sheets on a per-copy basis, the user presses the OK button while a “Shift” key is selected on the finishing menu selection screen as shown in
Once the user has designated the sort mode and entered a job, the CPU 901 in the CPU circuit unit 900 notifies the CPU 952 in the finisher controller 951 of information related to that job, such as the sheet size and the selection of the sort mode. According to some embodiments, after sheets have been discharged in one print job, shift/discharge operations are applied to sheets printed in the next print job so that the sheets printed in the next print job are discharged at a different position from the sheets discharged in the preceding job. Such shift/discharge operations applied for each print job are referred to as an inter-job shift.
When the image forming apparatus 10 discharges a sheet P to the finisher 500, the CPU 901 in the CPU circuit unit 900 notifies the CPU 952 in the finisher controller 951 of the start of sheet transfer. The CPU 901 also notifies the CPU 952 in the finisher controller 951 of sheet information, such as shift information and sheet width information of the sheet P. It is assumed here that the sheet width information is stored in the ROM 902 or the memory unit 903 in advance for each sheet size. For example, an A4-sized sheet has a width of 297 mm, an A4R-sized sheet has a width of 210 mm, and a B5-sized sheet has a width of 257 mm. A letter-sized sheet has a width of 279.4 mm. An A3-sized sheet can only be conveyed with the short edge thereof serving as the leading edge, and therefore has a width of 297 mm. Upon receiving the notification of the start of sheet transfer, the CPU 952 drives and rotates the motor M1, the buffer motor M2 and the discharge motor M3. As a result, the pairs of conveyance rollers 511, 512, 513, 514 and 515 shown in
When the flapper 541 is driven and rotated by the solenoid S1 to be situated in the position shown in
Next, a description is given of the alignment operations during a sort mode, using an example of the front shift operations, with reference to
As shown in
The following describes a flow of sheets during a shift-sort mode with reference to
When the image forming apparatus 10 discharges a sheet P to the finisher 500, the CPU 901 in the CPU circuit unit 900 notifies the CPU 952 in the finisher controller 951 of the start of sheet transfer. Upon receiving the notification of the start of sheet transfer, the CPU 952 drives and rotates the motor M1, the buffer motor M2 and the discharge motor M3. As a result, the pairs of conveyance rollers 511, 512, 513, 514 and 515 shown in
The following describes the operations of the alignment plates at the time of the shifting, using the exemplary case where the shift direction is changed from the front to the back, with reference to
Next, the alignment plates 711a and 711b move in the sheet width direction to their respective alignment waiting positions for the next sheet. More specifically, on a bundle of sheets that are already stacked on the receiving tray 701, a next sheet is to be discharged while being shifted toward the back compared to the bundle of already-stacked sheets. As shown in
Once the alignment plates 711a and 711b have moved to their respective alignment waiting positions, the alignment plates 711a and 711b are lowered toward the receiving tray 701 by a predetermined amount and wait until the next sheet is discharged onto the receiving tray 701 as shown in
Thereafter, as shown in
As described above, if the positions of sheets to be stacked are changed (shifted) in the width direction, the alignment plates are first raised upward away from the receiving tray, then lowered after changing the aligning positions of the alignment plates so as to prepare for alignment of the sheets to be discharged next. Each time a sheet is discharged onto already-stacked sheets, sheet alignment operations are executed at the shifted positions.
In this case, the alignment plate 711a that is in contact with (touches) the top surface of the topmost sheet of the stacked sheets does not move; instead, the alignment plate 711b that is not in contact with the stacked sheets moves in a direction orthogonal to the sheet conveyance direction and applies the alignment operations to the newly-discharged sheet. This can prevent the alignment plate 711a from sliding against and staining the top surface of the topmost sheet of the stacked sheets, or at least reduce the stain.
If a “Select Discharge Destination” key is selected on the finishing menu selection screen shown in
The following describes different width-mixed stack, in which a plurality of types of sheets having different widths are stacked on a receiving tray. If the “Select Sheet” key 418 is pressed on the screen shown in
Also, in the case where data generated by a computer is received and printed instead of copying images of originals, if the data includes a mixture of pages with different image sizes, a plurality of printed sheets having different widths will be stacked on a receiving tray in a mixed manner.
The above has described an example of different width-mixed stack that occurs in one print job. The following describes different width-mixed stack that occurs in two print jobs.
If the user selects the “Select Sheet” key 418 on the screen shown in
Also, in the case where data generated by a computer is received and printed instead of copying images of originals, if sheets to be used in different print jobs have different sizes, a plurality of sheets having different widths will be stacked on a receiving tray in a mixed manner.
When sheets having a smaller width than printed sheets that are already stacked on a tray are to be stacked and aligned on the already-stacked sheets, it is necessary to prevent the alignment plates from sliding against the topmost sheet of the already-stacked sheets through the movement for the alignment (reciprocating operations). In view of this, the following describes a procedure for setting a partition sheet that is inserted onto the topmost sheet as necessary.
If the user presses the “Applied Mode” key 419 on the screen shown in
A description is now given of page printing operations executed by the CPU 901 in the CPU circuit unit 900 in the controller according to the present embodiment with reference to a flowchart of
First, in step S1401, the CPU 901 identifies the size of a sheet P to be used in printing based on the input print settings and image data. Then, the CPU 901 proceeds to step S1402 and determines, based on the input from the sheet sensor 730 or 731, whether or not sheets that have already been printed (first sheets) are placed on a receiving tray onto which the printed sheet P should be discharged. Note that the receiving tray onto which the printed sheet P should be discharged may be decided on in accordance with the input print settings, or may have been decided on as the setting for the image forming apparatus 10. The CPU 901 proceeds to step S1403 if it determines that sheets are placed on the receiving tray onto which the sheet P (second sheet) should be discharged, and to step S1406 if it determines that no sheet is placed on the receiving tray onto which the sheet P (second sheet) should be discharged. In step S1403, the CPU 901 determines whether or not the sheet width W of the sheet P that was identified in step S1401 is equal to a variable W_prev that is stored in the memory unit 903 and indicates the sheet width of a preceding sheet. The CPU 901 proceeds to step S1406 if it determines that the sheet width W of the sheet P is equal to the variable W_prev, and to step S1404 if it determines otherwise.
In step S1404, the CPU 901 notifies the CPU 952 in the finisher controller 951 in the finisher 500 of sheet information of a partition sheet that was designated using the screens shown in
In step S1406, the CPU 901 notifies the CPU 952 in the finisher controller 951 in the finisher 500 of the information of the sheet P, and then proceeds to step S1407. In step S1407, the CPU 901 controls the printer controller 931 to print an image on the sheet P and to convey the printed sheet P to the finisher 500, and then proceeds to step S1408. In step S1408, the CPU 901 substitutes the width W of the sheet P that was printed in step S1401 into W_prev, and ends the page printing operations for the sheet P. Note that W_prev is stored in the memory unit 903.
Through the above processes, when sheets having a different size from sheets that were previously printed and are stacked on a tray are to be newly printed and discharged onto the same tray, the newly printed sheets can be discharged after discharging a partition sheet onto the already-stacked sheets. This makes it possible to prevent the already-stacked sheets from being stained or damaged by the alignment members coming into contact with the front surface of the already-stacked sheets through the alignment process applied to the newly printed sheets.
First, in step S1501, the CPU 952 determines whether or not it has been notified of sheet information by the CPU 901 in the image forming apparatus 10. This sheet information includes information indicating whether or not a sheet is a partition sheet, job information indicating whether the sheet is the first sheet or the last sheet in the job if the sheet is not a partition sheet, the sheet width W, and the offset amount Z. This sheet information may include information related to a single job, or information related to a plurality of jobs. The CPU 952 proceeds to step S1502 if it has been notified of the sheet information, and returns to step S1501 if it has not been notified of the sheet information. In step S1502, the CPU 952 determines whether or not a sheet to be conveyed is a partition sheet based on the sheet information received in step S1501. The CPU 952 proceeds to step S1524 (
X1=W/2+Z [Equation 1]
In step S1504, the CPU 952 calculates the back sheet edge position X2 shown in
X2=W/2−Z [Equation 2]
In step S1505, the CPU 952 determines whether or not the sheet to be conveyed is the first sheet in the print job based on the sheet information, or whether or not the alignment plates have been retracted with reference to an alignment plate retraction flag stored in the RAM 954. The CPU 952 proceeds to step S1506 if it determines that the sheet to be conveyed is the first sheet in the job or that the alignment plate retraction flag is set to TRUE, and proceeds to step S1518 if it determines otherwise. In step S1506, the CPU 952 drives and rotates the upper tray alignment motors M9 and M10 and the alignment plate elevator motor M13 for the upper tray 701 so as to move the alignment plates 711 from the default positions shown in
In step S1507, the CPU 952 determines whether or not the trailing edge of the sheet to be discharged onto the upper tray 701 has been detected based on the output from the conveyance sensor 574. The CPU 952 proceeds to step S1508 if the trailing edge of the sheet has been detected, and returns to step S1507 if the trailing edge of the sheet has not been detected. In step S1508, the CPU 952 determines whether or not a predetermined time period has elapsed since the trailing edge of the sheet was detected. The CPU 952 proceeds to step S1509 (
In step S1509, the CPU 952 determines the shift direction for the sheet based on the offset amount Z included in the sheet information. If Z is larger than or equal to “0”, the CPU 952 determines that the front shift is to be performed and proceeds to step S1510. If Z is smaller than “0”, the CPU 952 determines that the back shift is to be performed and proceeds to step S1515. In step S1510, i.e. in the case of the front shift, the CPU 952 drives and rotates the upper tray alignment motor M9 so as to execute the alignment operations by moving the alignment plate 711a toward the center of the receiving tray 701 and pressing the sheet P against the stopped alignment plate 711b as shown in
On the other hand, if the CPU 952 determines in step S1509 that the back shift is to be performed, the CPU 952 proceeds to step S1515. In step S1515, the CPU 952 drives and rotates the upper tray alignment motor M10 so as to execute the alignment operations by moving the alignment plate 711b toward the center of the receiving tray 701 and pressing the sheet against the stopped alignment plate 711a. Then, the CPU 952 proceeds to step S1516 and waits until a predetermined time period elapses since the alignment plate 711b was moved. Thereafter, the CPU 952 proceeds to step S1517, and drives and rotates the upper tray alignment motor M10 so as to move the alignment plate 711b away from the sheet P in the sheet width direction. The CPU 952 then proceeds to step S1513.
On the other hand, if the CPU 952 determines in step S1505 that the sheet to be conveyed is not the first sheet in the print job and the alignment plates have not been retracted, the CPU 952 proceeds to step S1518. In step S1518, the CPU 952 compares X1 and X2 respectively with X1_prev and X2_prev that are stored in the RAM 954. If X1 is equal to X1_prev and X2 is equal to X2_prev, the sheet to be conveyed will be stacked at the same position as the preceding sheet, and therefore the CPU 952 proceeds to step S1507. Otherwise, the CPU 952 proceeds to step S1519 and changes the waiting positions of the alignment plates 711 in the sheet width direction.
In step S1519, the CPU 952 drives and rotates the alignment plate elevator motor M13 for the upper tray such that, as shown in
After a sheet that has a different size from stacked sheets has been printed, the alignment plates move to and wait at the positions that are suited for the size and the offset of the printed sheet.
On the other hand, if the CPU 952 determines in step S1502 that the sheet to be conveyed is a partition sheet, the CPU 952 proceeds to step S1524 and determines whether or not the alignment plates have been retracted based on the value of the alignment plate retraction flag stored in the RAM 954. The CPU 952 proceeds to step S1526 if it determines that the alignment plates have been retracted, and to step S1525 if it determines otherwise. In step S1525, the CPU 952 drives and rotates the upper tray alignment motors M9 and M10 and the alignment plate elevator motor M13 for the upper tray so as to move the alignment plates 711a and 711b to the default positions shown in
As described above, according to the first embodiment, when sheets having a different width from preceding sheets that are already stacked on a receiving tray are to be stacked directly on the preceding sheets, a partition sheet is inserted between the preceding sheets and the sheets having the different width. In this way, when the alignment operations are applied to subsequent sheets, the alignment plates do not come into direct contact with and slide against the front surface of the stacked preceding sheets. Accordingly, a discharge process with a high alignment quality can be continued without interrupting printing, and the usability is improved. The above processes may be executed by storing a program for executing the above processes in the ROM 902 and causing the CPU 901 in the image forming apparatus 10 to execute the stored program. The finisher 500 may be controlled by the execution of the above processes. Also, the image forming apparatus 10 may include a receiving tray, and the above processes may be executed when sheets are discharged onto this receiving tray. The same goes for the embodiments described below.
Although the first embodiment has described the example in which sheets are discharged onto the receiving tray 701, namely the upper tray, the above processes can be executed similarly in the case where sheets are discharged onto the receiving tray 700, namely the lower tray. In this case, the CPU 952 detects the trailing edge of each sheet based on the output from the conveyance sensor 576, and executes the alignment operations by driving and rotating the lower tray alignment motors M11 and M12 and the alignment plate elevator motor M14 for the lower tray.
The above first embodiment has described a technique to, when sheets having a different width from preceding sheets are to be stacked directly on the preceding sheets, insert a partition sheet between the preceding sheets and the sheets having the different width so as to prevent stains and the like on the stacked sheets without interrupting a print process. However, if the subsequent sheets have a larger width than the stacked preceding sheets, the alignment process can be executed without the alignment plates sliding against the stacked preceding sheets. In view of this, the second embodiment describes the example in which, if subsequent sheets have a larger width than the stacked preceding sheets, the alignment process is executed without using a partition sheet and without interrupting printing. Note that a configuration of an image forming system according to the second embodiment is the same as the configuration of the image forming system according to the above-described first embodiment, and therefore a description thereof is omitted. In the present second embodiment, only features that are different from the first embodiment are described, and constituent elements having the same configurations as those in the first embodiment are described using the same reference numbers thereas.
A description is now given of page printing operations executed by the CPU 901 in the CPU circuit unit 900 in the controller according to the second embodiment with reference to a flowchart of
In step S1603, the CPU 901 determines whether or not the sheet width W of a sheet P that was identified in step S1601 is larger than or equal to a variable W_prev that is stored in the memory unit 903 and indicates the sheet width of a preceding sheet. If the CPU 901 determines that the sheet width W of the sheet P is larger than or equal to the variable W_prev, the CPU 901 proceeds to step S1606 without inserting a partition sheet. If the CPU 901 determines otherwise, the CPU 901 proceeds to step S1604. In the flowchart of
Through the above processes according to the second embodiment, only when sheets having a smaller sheet width than preceding sheets that are already stacked on a receiving tray are to be stacked directly on the preceding sheets, a partition sheet is inserted between the preceding sheets and the sheets having the smaller sheet width. On the other hand, when sheets having the same sheet width as or a larger sheet width than sheets that are already stacked on a receiving tray are to be stacked directly on the already-stacked sheets, the alignment process is executed without using a partition sheet and without interrupting printing. In this way, a discharge process with a high alignment quality can be continued without using a partition sheet and without interrupting printing, and the usability is improved. In addition, wasteful use of partition sheets can be restricted.
The second embodiment has described the example in which a partition sheet is inserted if subsequent sheets have a smaller width than stacked preceding sheets. However, if the inserted partition sheet has a smaller sheet width than the stacked preceding sheets, the preceding sheets protrude from the partition sheet on a receiving tray. This can lead to the possibility that the quality of an image on the topmost sheet of the stacked sheets may be reduced because the alignment plates still slide against the front surface of the topmost sheet.
In view of this, the third embodiment describes the example in which the user is warned if the partition sheet has a smaller sheet width than the stacked sheets. Note that a configuration of an image forming system according to the third embodiment is the same as the configuration of the image forming system according to the above-described first embodiment, and therefore a description thereof is omitted. In the third embodiment, only features that are different from the above-described embodiments are described, and constituent elements having the same configurations as those in the above-described embodiments are described using the same reference numbers thereas.
The following describes page printing operations executed by the CPU 901 in the CPU circuit unit 900 in the controller of the image forming apparatus 10 according to the third embodiment with reference to a flowchart of
In step S1704, the CPU 901 determines whether or not the sheet width of a partition sheet that was designated on the screen shown in
After proceeding to step S1706, the CPU 901 determines whether or not sheets are placed on the receiving tray onto which the printed sheet P is to be discharged based on the input from the sheet sensor 730 (or the sheet sensor 731 in the case of the lower tray 700). If the CPU 901 determines that sheets are placed on the receiving tray onto which the sheet P is to be discharged, the CPU 901 returns to step S1705. If the CPU 901 determines that no sheet is placed on the upper tray 701 based on the sheet sensor 730, the CPU 901 proceeds to step S1709. In the flowchart of
As described above, according to the third embodiment, when sheets having the same sheet width as or a larger sheet width than sheets that are already stacked on a receiving tray are to be stacked directly on the already-stacked sheets, the alignment process is executed without using a partition sheet and without interrupting printing. On the other hand, when sheets having a smaller sheet width than preceding sheets that are already stacked on the receiving tray are to be stacked directly on the preceding sheets, a partition sheet is inserted between the preceding sheets and the sheets having the smaller sheet width if the sheet width of the partition sheet is larger than or equal to the sheet width of the preceding sheets. If the sheet width of the partition sheet is smaller than the sheet width of the preceding sheets, the print process is interrupted, and a message for guiding the user to remove the stacked sheets from the tray is displayed to the user.
That is to say, when there is a possibility that the alignment process may reduce the image quality of the already-stacked sheets, a partition sheet is inserted. This makes it possible to obtain the effect of preventing reduction in the image quality of the already-stacked sheets and avoiding the interruption of printing. If the reduction in the image quality of the already-stacked sheets cannot be prevented even by the insertion of the partition sheet, necessary processes can be executed by interrupting printing through presentation of warning to the user.
The above third embodiment has described the example in which a partition sheet is inserted when sheets having a smaller sheet width than that of preceding sheets that are already stacked are to be stacked directly on the preceding sheets and the sheet width of the partition sheet is larger than or equal to the sheet width of the preceding sheets. This makes it possible to continue a discharge process with a high alignment quality without interrupting printing. However, in some cases, a partition sheet is inserted in the middle of a job. In such cases, in order to complete printed materials of one job as finished products after they have been discharged, it is necessary to remove the partition sheet from those printed materials.
In view of this, the fourth embodiment describes the example in which a partition sheet is inserted only between different jobs. Note that a configuration of an image forming system according to the fourth embodiment is the same as the configuration of the image forming system according to the above-described first embodiment, and therefore a description thereof is omitted. In the fourth embodiment, only features that are different from the third embodiment are described, and constituent elements having the same configurations as those in the third embodiment are described using the same reference numbers thereas.
The following describes page printing operations executed by the CPU 901 in the CPU circuit unit 900 in the controller of the image forming apparatus according to the fourth embodiment with reference to a flowchart of
In step S1904, the CPU 901 determines whether or not a sheet P that was identified in step S1901 is the first sheet in the job. The CPU 901 proceeds to step S1905 if it determines that the sheet P is the first sheet in the job, and to step S1906 if it determines otherwise. In the flowchart of
According to the above-descried fourth embodiment, when a printed sheet having a smaller sheet width than that of preceding sheets that are already stacked on a receiving tray is to be stacked directly on the already-stacked sheets, if the printed sheet is not the first sheet in the job, the print process is interrupted, and a message for instructing the removal of the already-stacked sheets on the receiving tray is displayed in step S1906. On the other hand, when a printed sheet having a smaller sheet width than preceding sheets that are already stacked on a receiving tray is to be stacked directly on the already-stacked sheets, if the printed sheet is the first sheet in the job and the sheet width of the partition sheet is larger than or equal to the sheet width of the preceding sheets, the partition sheet is inserted between the stacked preceding sheets and the printed sheet. If the sheet width of the partition sheet is smaller than the sheet width of the preceding sheets, the print process is interrupted, and a message for guiding the user to remove the preceding sheets stacked on the receiving tray is displayed to the user.
This not only makes it possible to obtain the effect of the first to third embodiments described above, but also prevents a partition sheet from being inserted into printed materials of one job. Accordingly, even when a partition sheet is used, it is not necessary to remove the partition sheet from printed materials of one job.
In a system that has a mechanism for counting the number of discharged sheets and charging the user in accordance with the counted number, partition sheets are also counted, and therefore there is a possibility of charging the user an inappropriate fee. In view of this, the fifth embodiment describes an example of an image forming system that does not count partition sheets. Note that a configuration of the image forming system according to the fifth embodiment is the same as the configuration of the image forming system according to the above-described first embodiment, and therefore a description thereof is omitted. In the fifth embodiment, only features that are different from the fourth embodiment are described, and constituent elements having the same configurations as those in the fourth embodiment are described using the same reference numbers thereas.
When the CPU 952 in the finisher controller 951 in the finisher 500 according to the fifth embodiment detects the trailing edge of a sheet based on the output from the sheet sensor 574 or 576, the CPU 952 notifies the CPU circuit unit 900 in the controller in the image forming apparatus 10 of the discharge of the sheet. When the CPU 901 is notified of the discharge, the CPU 901 increments a counter memory stored in the memory unit 903. Information of the counter memory stored in the memory unit 903 is stored in a non-volatile memory so that the counted value thereof can be held even when the power of the image forming apparatus 10 is off.
The following describes page printing operations executed by the CPU 901 in the CPU circuit unit 900 in the controller of the image forming apparatus 10 according to the fifth embodiment with reference to the flowcharts of
After conveying a partition sheet to the finisher 500 in step S2009, the CPU 901 proceeds to step S2010 and determines whether or not the partition sheet has been discharged based on the output from the sheet sensor 574 or 576. The CPU 901 proceeds to step S2011 if it determines that the partition sheet has been discharged, and returns to step S2010 if it determines otherwise. The CPU 901 skips an incrementing process in step S2011 and proceeds to step S2012 (
After conveying the sheet P to the finisher 500 in step S2013, the CPU 901 proceeds to step S2014 and determines whether or not the sheet P has been discharged based on the output from the conveyance sensor 574 or 576. The CPU 901 proceeds to step S2015 if it determines that the sheet P has been discharged, and returns to step S2014 if it determines otherwise. The CPU 901 increments the counter memory stored in the memory unit 903 in step S2015, and proceeds to step S2016. In the flowchart of
As described above, according to the fifth embodiment, the incrementing process is not executed if a conveyed sheet is a partition sheet. This makes it possible to prevent the user from being charged an inappropriate fee, thus improving the usability.
The above first to fifth embodiments have described the example in which whether or not a partition sheet should be inserted is controlled based on the difference between the width of printed sheets that are already stacked on a receiving tray and the width of a printed sheet that is to be conveyed and stacked. However, the present invention is not limited in this way. Alternatively, whether or not a partition sheet should be inserted may be controlled based on information of the size of printed sheets that are already stacked on the receiving tray and on information of the size of a sheet to be printed. For example, control may be performed to insert the partition sheet when the printed sheets that are already stacked on the receiving tray have an A4R size and the sheet to be printed has an A4 size.
In the first to fifth embodiments described above, the user selects a partition sheet in advance using the screens shown in
Furthermore, the use of partition sheets may be restricted in accordance with sheet attributes such as a size, a color, and a basis weight. For example, only sheets that have a basis weight of 100 g/m2 may be selectable as partition sheets.
Aspects of the present invention can also be realized by a computer of a system or apparatus (or devices such as a CPU or MPU) that reads out and executes a program recorded on a memory device to perform the functions of the above-described embodiments, and by a method, the steps of which are performed by a computer of a system or apparatus by, for example, reading out and executing a program recorded on a memory device to perform the functions of the above-described embodiments. For this purpose, the program is provided to the computer for example via a network or from a recording medium of various types serving as the memory device (for example, computer-readable medium.
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 changes and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2012-244806, filed Nov. 6, 2012, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-244806 | Nov 2012 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5316279 | Corona et al. | May 1994 | A |
| 5848346 | Takashiro | Dec 1998 | A |
| 6227531 | Guerrero et al. | May 2001 | B1 |
| 7681881 | Kunieda et al. | Mar 2010 | B2 |
| 8251362 | Konishi | Aug 2012 | B2 |
| Number | Date | Country |
|---|---|---|
| 2006-206331 | Aug 2006 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20140125001 A1 | May 2014 | US |
