Patent Grant
9354579
1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine or a printer for forming output sheet bundles each inserted with one or more tabbed sheets, and relates to a control method for the image forming apparatus and a storage medium storing a program for executing the control method.
2. Description of the Related Art
Conventionally, there has been proposed an image forming apparatus having a tabbed sheet mode for creating output sheet bundles in each of which one or more tabbed sheets are inserted at positions corresponding to designated pages for the purpose of adding headings or dividing into chapters.
In the tabbed sheet mode, tabbed sheet bundles each comprised of a plurality of tabbed sheets which are different in tab position from one another are generally used. In an example of
Accordingly, image forming apparatuses have been proposed that are configured to automatically discharge surplus tabbed sheets to the outside each time an output sheet bundle is produced. For example, there is an image forming apparatus configured to discharge output sheet bundles and surplus tabbed sheets to different discharge trays (see, Japanese Laid-open Patent Publication No. 2002-3063).
However, with the image forming apparatus that discharges surplus tabbed sheets after creation of each output sheet bundle, it is necessary to start image formation for the next output sheet bundle after waiting for discharge of the surplus tabbed sheets. In particular, in the case of a double-sided printing job in which tabbed sheets are inserted into between double-sided printed recording sheets to produce a plurality of output sheet bundles, it is necessary, after a last recording sheet used for creation of each output sheet bundle is double-sided printed and discharged to the outside of the apparatus, that a conveyance mode must be changed, surplus tabbed sheets must be discharged, and image formation on recording sheets used for creation of the next output sheet bundle must be started. As a result, the productivity in creating output sheet bundles is lowered.
A double-sided printing job is primarily performed in such away that a sheet interval does not become excessively large at a break between output sheet bundles. For example, double-sided circulation control is made in which a top sheet used for creation of output sheet bundle is started to be fed, without waiting for completion of double-sided printing on a last sheet used for creation of preceding output sheet bundle. As a result, a sheet interval does not become excessively large at a break between output sheet bundles even during the double-sided printing job, whereby high productivity can be maintained.
However, if surplus tabbed sheets are discharged after creation of each output sheet bundle as in the aforementioned conventional image forming apparatus, it is necessary to discharge surplus tabbed sheets after waiting for completion of double-sided printing and discharge of the last sheet used for creation of output sheet bundle. As a result, double-sided circulation control is disconnected at a break between output sheet bundles, and therefore the productivity of image formation is lowered.
The present invention provides an image forming apparatus capable of suppressing the productivity of image formation from being lowered due to discharge of surplus tabbed sheets in a double-sided printing job in which output sheet bundles are produced by inserting tabbed sheets into each bundle of double-sided printed recording sheets, and provides a control method for the image forming apparatus and a storage medium storing a program for executing the control method.
According to one aspect of this invention, there is provided an image forming apparatus comprising a first supply unit configured to supply at least one tabbed sheet one by one from each of a plurality of tabbed sheet bundles each comprised of tabbed sheets which are different in tab position from one another, a second supply unit configured to supply recording sheets, a conveyance unit configured to convey the tabbed sheet supplied by the first supply unit and the recording sheets supplied by the second supply unit and to discharge them to outside, an image forming unit configured to form images on both surfaces of each of the recording sheets conveyed by the conveyance unit, and a control unit configured, in a case where at least one surplus tabbed sheet not inserted into a corresponding one of at least one output sheet bundle is occurred in each of the tabbed sheet bundles when the at least one output sheet bundle is produced in each of which the at least one tabbed sheet is inserted into a recording sheet bundle comprised of recording sheets each formed with images on its both surfaces by a double-sided image forming operation of the image forming unit, to control the first supply unit and the conveyance unit such that the surplus tabbed sheet is conveyed subsequently to conveyance of the tabbed sheet to be lastly inserted into a corresponding one of the at least one output sheet bundle.
With this invention, surplus tabbed sheets are discharged subsequently to the conveyance of the last tabbed sheet constituting an output sheet bundle, whereby it becomes possible to suppress the productivity of image formation from being lowered due to discharge of surplus tabbed sheets in a double-sided printing job to produce output sheet bundles by inserting tabbed sheets into each bundle of double-sided printed recording sheets.
Further features of the present invention will become apparent from the following description of an exemplary embodiment with reference to the attached drawings.
The present invention will now be described in detail below with reference to the drawings showing a preferred embodiment thereof.
As shown in
Referring to
An image forming unit 110 is constituted by the photosensitive drum 111 together with a primary charging device 112, a developing device 119, a transfer charging device 118, a cleaning device 116, and a pre-exposure lamp 114, which are disposed near the photosensitive drum 111.
The photosensitive drum 111 is rotated by a motor (not shown) in a direction indicated by an arrow in
Upper and lower sheet feed cassettes 131, 132 store sheets (recording sheets or tabbed sheets). Sheets stored in the upper sheet feed cassette 131 are each fed by a pickup roller 133 and conveyed by a sheet feed roller 135 to a registration roller 137. Sheets stored in the lower sheet feed cassette 132 are each fed by a pickup roller 134 and conveyed by a sheet feed roller 136 to the registration roller 137. In other words, the pickup rollers 133, 134 and the sheet feed rollers 135, 136 function as a first supply unit for supplying tabbed sheets and a second supply unit for supplying recording sheets.
Each sheet conveyed to the registration roller 137 is conveyed to a transfer belt 138, and a toner image on the photosensitive drum 111 is transferred to the sheet by the transfer charging device 118.
Residual toner on the photosensitive drum 111 is cleaned by the cleaning device 116, and residual electric charge is erased by the pre-exposure lamp 114.
The sheet transferred with the toner image is separated from the transfer belt 138. The toner image on the sheet is re-charged by pre-fixing charging devices 139, 140 and pressurized and heated by a fixing device 141, whereby the toner image is fixed to the sheet. Then, the sheet is discharged by a sheet discharge roller 142 to the outside of the image forming apparatus 100.
A deck 150 provided in the image forming apparatus 100 is configured to be capable of storing e.g., up to 4000 sheets. The deck 150 has a lifter 151 that moves up according to the amount of sheets such that the top sheet is always in contact with a sheet feed roller 152. A multi-manual sheet feeder/tray 153 is configured to be capable of storing e.g. up to 100 sheets.
A sheet discharge flapper 164 is provided to make a changeover between a path toward an inversion path 167 and a path for sheet discharge. When the changeover to the path for double-sided recording is made by the sheet discharge flapper 164, the sheet fed from the sheet discharge roller 142 is turned upside down by the inversion path 167, is introduced to a lower conveyance path 166, and is conveyed from the lower conveyance path 166 to the registration roller 137. On the other hand, when the changeover to the path for sheet discharge is made by the sheet discharge flapper 164, the sheet is discharged by a discharge roller 160 disposed near the sheet discharge flapper 164 to a discharge port of the image forming apparatus 100.
To discharge the sheet fixed with the toner image to the discharge port, the changeover toward the inversion path 167 is made by the sheet discharge flapper 164. After the trailing end of the sheet passes through a first feed roller 161, the sheet is conveyed by the inversion roller 163 toward the second feed roller 162. Then, the sheet turned upside down is discharged by the discharge roller 160 to the discharge port.
The sheet post-processing apparatus 190 is provided to align and staple sheets discharged from the image forming apparatus 100. In a case that a post-processing operation such as sorting or stapling has not been set through an operation unit 172 (see
One of the sheet discharge trays 191, 192 is moved by a motor (not shown) to a position where it is in alignment with the processing tray 193. In a case that the post-processing operation has been set, the sheet discharge tray 192 is normally moved to the position where it is in alignment with the processing tray 193, and sheet bundles are discharged to the sheet discharge tray 192. However, if the sheet discharge tray 192 is in a state full of sheet bundles, the sheet discharge tray 191 is moved to the position where it is in alignment of the processing tray 193 and sheet bundles are discharged to the tray 191.
As shown in
The CPU 171 executes control programs stored in the ROM 174 to thereby control the entirety of the apparatus 100. The RAM 175 is used as a work area that temporarily stores results of computation by the CPU 171, etc.
The input/output port 173 is connected with actuators (not shown) such as motors and clutches for driving various parts of the image forming apparatus 100, and is also connected with sensors (not shown) for detecting sheet conveyance positions, and the like. The CPU 171 controls input and output via the input/output port 173.
The operation unit 172 instructs the CPU 171 to change an image formation operation mode, display contents, or the like according to key input by a user. The operation unit 172 displays a state of the image forming apparatus 100 notified from the CPU 171, and also displays an operation mode set by key input. The image processor 170 processes an electrical signal supplied from the CCD sensor 109 (see
In
Ten keys 607 are used to input numerical values to set the number of sheets to be subjected to image formation and to set mode setting, and also used to input a telephone number on a fax setting screen. A clear key 608 is used to clear settings input through the ten keys 607, and a reset key 605 is used to restore the set number of sheets to be subjected to image formation, set operation mode, selected sheet feed stage, or the like to the default.
A start key 603 is used to start an image formation operation. Red and green LEDs (both not shown) are provided at a center of the start key 603. The red LED is turned on when the image formation operation cannot be started, whereas the green LED is turned on when the image formation operation can be started. A stop key 604 is used to stop the image formation operation.
When a setting key 606 is pressed, a setting screen (not shown) is displayed to enable the user to change settings of the image forming apparatus 100. For example, the user can change a set time up to when a setting is automatically cleared, and can change settings of general functions common to print and copy.
A display panel 610 is comprised of e.g. a liquid crystal display with touch panel, and display contents are changed according to the set mode.
When a selection key 614 is pressed, a setting screen (not shown) for setting any of the sheet feed cassettes 131, 132, the deck 150, and the manual sheet tray 153 as a sheet feeding source is displayed on the display panel 610.
Keys 615 to 618 are magnification setting keys for setting magnification in copying (reduction, same size, enlargement, and zoom). When an application mode setting key 613 is pressed, a setting screen for setting an application function mode such as multiple action mode, reduction layout mode, and cover sheet/slip sheet mode is displayed on the display panel 610. In an example of
When a double-sided operation setting key 611 is pressed, a setting screen (not shown) is displayed. On the setting screen, it is possible, for example, to selectively set a “single-sided to double-sided” mode where a double-sided output is generated from two single-sided documents, a “double-sided to double-sided” mode where a double-sided output is generated from a double-sided document, or a “double-sided to single-sided” mode where two single-sided outputs are generated from a double-sided document.
When a soft key 612 is pressed, a setting screen (not shown) is displayed on which an operation mode of the sheet post-processing apparatus 190 and a sorting mode to sort output sheets by using the image memory 176 can be set.
A proof print mode key 619 is operated to set a proof print mode where if the sorting mode has been set and if a plurality of sheet bundles are output, a printing operation is temporarily stopped at completion of output of each sheet bundle, thereby enabling the user to confirm the finished sheet bundle. The user can select continuing the printing operation if the finished bundle is OK, and can select terminating the printing operation if the finished bundle is NG.
When the user setting key 606 of the operation unit 172 is pressed, a setting screen (not shown) is displayed for setting an initial value of discharge tray for each job type. When a discharge tray key 620 is pressed on the display panel 610, a setting screen (third setting unit) is displayed for setting a discharge tray for each job.
At a lower part of the display panel 610, an operation state of other function mode (described later) is displayed in single line.
As described above, various keys are displayed on the display panel 610. It should be noted that there is a case where no setting screen can be displayed in response to the press of a key. In that case, the key is displayed in half-tone dot meshing to indicate that the key cannot be operated.
It should be noted that in the example of
Next, a description will be given of a recording sheet conveyance path with reference to
As shown in
The conveyance path 200 is a path along which a recording sheet fed from any of the manual sheet tray 153 and the sheet feed cassettes 131, 132 (which are shown in
The conveyance path 202 is a path along which the recording sheet to which the toner image on the photosensitive drum 111 has been transferred is introduced into the conveyance path 203 via the fixing device 141. The conveyance path 204 is a path along which the recording sheet introduced into the conveyance path 203 is discharged to the outside. The conveyance path 205 is a path along which the recording sheet introduced into the conveyance path 203 is refed to between the photosensitive drum 111 and the transfer charging device 118. The conveyance path 206 is a path where the recording sheet conveyed along the conveyance path 203 is switched back and guided to the conveyance path 205.
In the face-up sheet discharge mode (non-inversion discharge mode), a recording sheet formed with an image is discharged to the outside, with its front surface upward. In the face-down sheet discharge mode (inversion discharge mode), a recording sheet formed with an image is discharged to the outside, with its back surface upward. In the following description, it is assumed that recording sheets are fed from the upper sheet feed cassette 131.
In the single-sided image formation in face-up sheet discharge mode, a recording sheet S fed from the upper sheet feed cassette 131 is first conveyed via the conveyance path 200 to between the photosensitive drum 111 and the transfer charging device 118, as shown in
On the other hand, in the single-sided image formation in face-down sheet discharge mode, a recording sheet S fixed with a toner image is temporarily introduced into the conveyance path 203 via the conveyance path 202, and then discharged to the outside via the conveyance path 204, as shown in
In
In the double-sided image formation, as shown in
To perform double-sided image formation on a plurality of recording sheets, first an image is formed on and fixed to the first surface of the top recording sheet fed from the upper sheet feed cassette 131. The top recording sheet fixed with the image is switched back and introduced into the sheet refeeding conveyance path 205, and is temporarily stopped at a stop position 210 for waiting for arrival of timing of image formation on the second surface. At a timing where image formation on the second surface of the top recording sheet has been prepared, the top recording sheet is refed and conveyed via the conveyance path 200 to between the photosensitive drum 111 and the transfer charging device 118. Then, image formation on the first surface of a recording sheet next fed from the sheet feed cassette and image formation on the second surface of the recording sheet refed from the conveyance path 205 are alternately performed.
In the following, the number of recording sheets present on the double-sided circulation path starting from the conveyance path 200 and returning thereto via the conveyance paths 202, 203, 206, and 205 will be referred to as the number of circulating sheets, and image formation on both surfaces of respective ones of recording sheets on the double-sided circulation path will be referred to as the circulating image formation.
In
In the double-sided image formation, after image formation on the second surface of the top recording sheet, image formation on first surfaces of recording sheets and image formation on second surfaces of recording sheets are alternately performed. After completion of image formation on the first surface of the last recording sheet among recording sheets to be subjected to the double-sided image formation, image formation is only performed on the second surfaces of recording sheets already formed with images on their first surfaces. With such circulating image formation, the productivity is lowered because a recording sheet interval becomes greater in a time period until recording sheets whose number is equal to the number of circulating sheets are disposed on the double-sided circulation path and in a time period from when image formation on the first surface of the last recording sheet is completed to when image formation on the second surface of the last recording sheet is finished.
It should be noted that in
Next, with reference to
In a case that the number of circulating sheets is three, first and second recording sheets S1, S2 are sequentially fed with a predetermined sheet interval therebetween as shown in
When the first recording sheet S1 is refed, image formation is performed on the second surface of the recording sheet S1, and the third recording sheet S3 is subsequently supplied from the upper sheet feed cassette 131. At that time, as shown in
Referring to
In a case that the number of circulating sheets is five, as shown in
When the recording sheet S1 is refed, image formation is performed on the second surface of the recording sheet S1. Subsequently, image formation is performed on the first surface of the recording sheet S4. At this time, as shown in
Referring to
As described above, recording sheets whose number is equal to the number of circulating sheets are fed or refed from when one recording sheet is started to be fed for image formation on its first surface to when the one recording sheet is refed after having rounded the double-sided circulation path. It should be noted that the sheet interval shown by each of the broken rectangles in
The double-sided image formation for the first five recording sheets is performed in the same manner as with the case of
To perform double-sided image formation on a sixth recording sheet S6, no trouble is caused even if the recording sheet S6 is fed at a timing (denoted by symbol t1 in
In this example, however, since single-sided image formation is designated for the sixth recording sheet S6, the recording sheet S6 is not introduced into the sheet refeeding conveyance path 205 for double-sided image formation, but discharged to the outside. Accordingly, if the recording sheet S6 is fed at timing t1, recording sheets are discharged in a wrong order.
To maintain a correct order of sheet discharge, it is necessary to feed the sixth recording sheet S6 at timing t2 after the refeeding of the fifth recording sheet S5 for image formation on its second surface. Subsequently, single-sided image formation is performed on the recording sheet S6, and double-sided image formation is performed on the remaining five recording sheets S7 to S11. In that case, circulation of double-sided image formation is broken by the single-sided image formation on the recording sheet S6, and therefore, new circulation of five circulating sheets is started from the seventh recording sheet S7 for double-sided image formation.
In a printing job where double-sided image formation and single-sided image formation are mixed, it is necessary to perform blank sheet feeding to adjust a sheet feed timing at start of circulating image formation after single-sided image formation, as described above, in order to feed/refeed recording sheets in the order shown in
Prior to the printing process being started, the user performs various settings of the image forming apparatus 100 as described below.
When a “tabbed sheet feed position” key 710, a “number of tabs” key 711, or a “page to be inserted with tabbed sheet” key 712 is pressed on the setting screen of
The above-described various settings are made, and a plurality of tabbed sheet bundles each comprised of tabbed sheets whose number is equal to the set number of tabs are loaded to the set tabbed sheet feed stages. In that state, when the user presses the start key 603 of the operation unit 172 shown in
In the printing process of
Next, the CPU 171 determines whether or not the tabbed sheet to be fed is the last tabbed sheet to be used for formation of the output sheet bundle by comparing the number of insertion positions set on the tabbed sheet position setting screen 740 of
If determined in step S103 that the tabbed sheet to be fed is the last tabbed sheet to be used for formation of the output sheet bundle, the CPU 171 determines whether or not the tabbed sheet to be fed will be inserted into the last output sheet bundle among a plurality of output sheet bundles to be subjected to the present printing process based on e.g. the number of sets of bundles that has been set through the ten keys 607 shown in
If determined in step S104 that the tabbed sheet to be fed will not be inserted into the last output sheet bundle, the CPU 171 counts the number of surplus tabbed sheets (step S105), and controls conveyance of the last tabbed sheet of the output sheet bundle (step S106). Next, the CPU 171 (decision unit) decides a discharge destination to which surplus tabbed sheets are to be discharged based on e.g. a discharge destination of surplus tabbed sheets set on a screen, which is displayed in response to the discharge tray key 620 shown in
If determined in step S104 that the tabbed sheet to be fed will be inserted into the last output sheet bundle, the CPU 171 controls conveyance of the tabbed sheet (step S110), and proceeds to step S109.
If determined in step S101 that the sheet to be fed is not a tabbed sheet, i.e., if the sheet to be fed is a recording sheet, the CPU 171 determines whether or not it is necessary to change the conveyance mode (step S111). If the preceding sheet is a tabbed sheet, the conveyance mode changed to the single-sided image formation mode in step S102 in the preceding cycle of the present process must be changed to the double-sided image formation mode.
If determined in step S111 that it is necessary to change the conveyance mode, the CPU 171 changes the conveyance mode to the double-sided image formation mode (circulating image formation) (step S112), controls conveyance of the recording sheet (step S113), and controls image formation on the recording sheet (step S114). Subsequently, the process proceeds to step S109.
In step S109, the CPU 171 determines whether or not the recording sheet, which is the object of determination, is the last recording sheet in the printing process. In other words, the CPU 171 determines whether or not the recording sheet is the last recording sheet in the last output sheet bundle among the plurality of output sheet bundles to be subjected to the printing process. If determined in step S109 that the recording sheet is not the last recording sheet, the process returns to step S101. On the other hand, if determined that the recording sheet is the last recording sheet, the process proceeds to step S115.
In these examples, tabbed sheet bundles are used each comprised of five tabbed sheets as shown in
A tabbed sheet T1 is inserted at timing t2 where image formation on the second surface of the fifth recording sheet S5 is completed. It should be noted that it is possible, where required, to perform image formation only on one surface of the tabbed sheet T1.
In the sheet feeding/refeeding control of
In the case of creating each output sheet bundle as described above, four surplus tabbed sheets T2 to T5 are occurred since each of tabbed sheet bundles set in the image forming apparatus is comprised of five tabbed sheets. Thus, after waiting for completion of image formation on the last recording sheet of one output sheet bundle, i.e., on the second surface of the tenth recording sheet S10, the four surplus tabbed sheets T2 to T5 are discharged in the single-sided image formation mode to a discharge destination. Then, after waiting for completion of discharge of the last surplus tabbed sheet T5, a second output sheet bundle is started to be produced at timing t3.
As described above, circulating image formation must be temporarily stopped to perform processing for discharging surplus tabbed sheets between image formation on the last recording sheet of one output sheet bundle and image formation on the first recording sheet of the next output sheet bundle. Accordingly, the productivity of image formation is lowered.
On the other hand, in the sheet feeding/refeeding control of
Referring to
Since no recording sheet is fed or refed subsequently to the last output sheet bundle, surplus tabbed sheets in this embodiment are not discharged after completion of image formation on the last recording sheet used to form the last output sheet bundle, but discharged subsequently to conveyance of the last tabbed sheet in the last tabbed sheet bundle as previously described, whereby the productivity of image formation on the last bundle can be improved further.
As described above, according to this embodiment, it is possible to eliminate a time for waiting for discharge of surplus tabbed sheets (i.e., a time for waiting for refeeding of the last recording sheet of each output sheet bundle for image formation on the second surface thereof) that can occur in the conventional image forming apparatus in a case that surplus tabbed sheets are occurred in the double-sided image formation on recording sheets in the tabbed sheet mode. As a result, the productivity can be improved.
While the present invention has been described with reference to an exemplary embodiment, it is to be understood that the invention is not limited to the disclosed exemplary embodiment. 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. 2012-159602, filed Jul. 18, 2012, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-159602 | Jul 2012 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6393232 | Osari et al. | May 2002 | B1 |
| 6539198 | Miyajima | Mar 2003 | B2 |
| 20120003023 | Igarashi | Jan 2012 | A1 |
| 20120062943 | Maeda | Mar 2012 | A1 |
| Number | Date | Country |
|---|---|---|
| 2002-003063 | Jan 2002 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20140023415 A1 | Jan 2014 | US |
