JP4270935B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine or a printer that forms images on both sides of a sheet, and in particular, an image forming apparatus capable of optimally performing a double-sided printing order based on various printing conditions of print data. About.
[0002]
[Prior art]
In recent years, in an image forming apparatus such as a copying machine or a printer that forms images on both sides of a sheet, the first side is continuously printed, and printing on the second side is waited until a predetermined condition is satisfied. If the condition is satisfied, an image forming apparatus is proposed that determines the double-sided printing order in such a manner that the first side is put on standby and the second side is printed (Patent Document 1).
Some image forming apparatuses capable of duplex printing are equipped with a function called interleaf. This is intended to increase the productivity of double-sided printing by placing a plurality of sheets on the conveyance path of the image forming unit. Normally, two sheets can be placed on the conveyance path. In the case of an image forming apparatus of the face-down printing method, the duplex printing order performed by the image forming apparatus is normal 2 → 1 → 4 → 3 → 6. Instead of → 5, the order is 2 → 4 → 1 → 6 → 3 → 5 (numbers indicate page numbers).
[Patent Document 1]
Japanese Patent No. 2879933 gazette
[Problems to be solved by the invention]
However, in this interleaf method, when the number of sheets that can be loaded at one time changes depending on the length of the conveyance path of the image forming apparatus, or depending on various printing conditions of the page, a print waiting state may occur, In some cases, the leaf itself may be impossible, and double-sided printing control becomes complicated.
The present invention has been made to solve the above-mentioned problems, and its purpose is to rearrange the print page order based on various printing conditions and to perform double-sided printing in a form that matches the performance of the engine. Thus, an image forming apparatus capable of optimally performing the duplex printing order is provided.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is an image having an interleaf function capable of holding N sheets of paper on the conveyance path and performing duplex printing of front and back side print data. A forming apparatus, wherein a print waiting list in which print data for the back side is sequentially stored from the top of the list in the order of input, and print data for the front side are sequentially stored from the top of the list in the order of input, and the back side is included in the print wait list When the print data for N is stored in succession, the print-ready preparation list for moving the front-side print data stored at the head to the end of the print-wait list and the print-wait list are stored. Control means for executing printing in the order in which the print data is printed, and when there is no consumable during printing of the print data for the back side, the print data for the front side that is paired with the print data for the back side is excluded. From the waiting list and print waiting ready list, and deletes the other print data.
Therefore, if there are no consumables during the printing of 4 pages or 2 sheets of double-sided printing, for example, if there are no consumables during printing of the 2nd page, the back side page (even page) in the state before starting printing is displayed from the print waiting list. To find. If the back page is not found, the print preparation list is searched. If there is a page in the print preparation list, the first page of the print preparation list is linked to the end of the print preparation list. Further, the front page (odd page) paired with the pre-print start page that was not found in these processes is searched from both the print waiting list and the print ready list, and both the front and back pages found are respectively searched. It is possible to delete only the page from which printing has been started and to reliably leave the page.
According to a second aspect of the present invention, in the image forming apparatus of the first aspect, optimal double-sided printing is performed by changing the double-sided printing order according to the length of the transport path.
Therefore, since the duplex printing order is changed according to the length of the transport path, the duplex printing mode of the engine can be effectively selected, and the duplex printing speed can be improved.
According to a third aspect of the present invention, in the image forming apparatus of the first aspect, the print order is controlled by switching the page order in the print wait list to be connected depending on the color difference of the print data connected to the print wait list. It is characterized by that.
Therefore, the page order in the print waiting list to be connected is switched depending on the color difference of the print data connected to the print wait list, so the double-sided print mode of the engine can be effectively used even for pages with different conditions. It is possible to select the two-sided printing speed.
According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect, the printing order is controlled by switching the page order in the print waiting list to be connected according to the size of the printing paper.
Therefore, since the page order in the print waiting list to be connected is switched depending on the size of the printing paper, the duplex printing mode of the engine can be effectively selected even for pages with different conditions. It becomes possible to improve the duplex printing speed.
[0005]
According to a fifth aspect of the present invention, in the image forming apparatus of the first aspect, the printing order is controlled by switching the page order in the print waiting list to be connected according to the thickness of the printing paper.
Therefore, the page order in the connected print waiting list is switched depending on the thickness of the print paper. Therefore, even for pages with different conditions, the double-sided printing mode of the engine can be effectively selected. It becomes possible to improve the printing speed.
According to a sixth aspect of the present invention, in the image forming apparatus of the first aspect, the print order is controlled by switching the page order in the print waiting list to be connected depending on the owner of the print job. .
Therefore, because the page order in the connected print waiting list is switched depending on the owner of the print job, the double-sided printing mode of the engine can be effectively selected even for pages with different conditions. Thus, it is possible to improve the double-sided printing speed .
[0006]
According to a seventh aspect of the present invention, in the image forming apparatus of the first aspect, when single-sided printing is requested during double-sided printing, the page order in the print waiting list to be connected is switched to control the printing order. It is characterized by.
Therefore, when single-sided printing is requested during double-sided printing, the page order in the print waiting list to be connected is switched, so even if the page has different conditions, the double-sided printing mode of the engine is effectively selected. It is possible to improve the double-sided printing speed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic block diagram of an image forming apparatus according to an embodiment of the present invention.
As shown in FIG. 1, the image forming apparatus 1 includes a CPU 3 that performs overall control, a ROM 5 that stores programs executed by the CPU 3, a RAM 7 that is used when the CPU 3 executes processing, and a host computer 9. An I / F 11 that performs communication, a memory 13 that develops print data, and an image forming unit 15 that forms a print image. Then, the CPU 3 controls the image forming unit 15 in accordance with a print command from the host computer 9 or the like, and executes a printing operation.
The image forming unit 15 performs double-sided printing by reversing and re-feeding the paper for which the printing operation has been completed, and printing on the reverse printing surface of the re-fed paper. An interleaf method is adopted in which a plurality of sheets are placed on the sheet conveyance path to increase the productivity of double-sided printing.
In the present invention, a “printing waiting list” representing a printing order is provided to realize an interleaf system in which a plurality of sheets are placed on the conveyance path of the image forming unit 15 to increase the productivity of double-sided printing. In addition, another “print waiting list” is set up. That is, two print waiting lists are provided.
Then, the CPU 3 does not connect the requested page as it is to the print waiting list, but temporarily switches the list to be connected according to the surface attribute (front and back of the page) of the page, and this print waiting ready list By changing the number of pages that can be connected, the interleaf system can be realized regardless of the length of the conveyance path of the image forming unit 15.
The print waiting list and the print waiting preparation list are provided in the memory 13 for expanding the print data.
In addition, the image forming unit 15 has a duplex unit that reverses and re-feeds the paper on which the printing operation has been completed.
[0008]
Next, the double-sided printing control operation of the image forming apparatus 1 will be described in detail.
First, the CPU 3 compares the page to be printed with the page information existing before and after the page based on the stored print page information and determines a print waiting list to be linked. Further, when a page with different printing conditions is found by scanning the printing page, the printing mode is changed before printing the page with different conditions. In the case of this embodiment, the page attributes (front and back of the page) of the page are linked to the print waiting list when the page is the front side, and to the print waiting list when the page is the back side. .
Note that each page linked to the list is linked to a page that is paired with itself. Paired pages are the back and front of the same sheet.
Next, the sequence for determining the printing order in duplex printing will be described with reference to FIGS.
Here, the print page is double-sided printing of 6 pages, and the printing conditions of these pages are the same.
In double-sided printing in an image forming apparatus that performs face-down printing, printing is performed in the order of back side (even page) → front side (odd page). For this reason, print requests from the CPU 3 are sent in the order of pages 2 → 1 → 4 → 3 → 6 → 5. Note that the image forming unit 15 assumed this time is an engine that can simultaneously feed two sheets of paper on the conveyance path.
[0009]
(1) Processing of the first page (second page) Since the processing surface attribute of the first page (second page) is the back surface (even page), the pages are connected to the print waiting list. At this time, since the print waiting list is an empty list (no page), this page (second page) is directly connected to the print waiting list (see FIG. 2).
(2) Processing of next page (first page) Since the processing surface attribute of the first page is front (odd page), the page is connected to the print preparation list. At this time, since the print waiting preparation list is an empty list (no page), this page (first page) is directly connected to the print waiting preparation list (see FIG. 3).
(3) Processing of next page (4th page) Since the processing surface attribute of the 4th page is the back surface (even page), the page is connected to the print waiting list. At this time, since the page (second page) already exists in the print waiting list, the print condition with that page is compared. Since the printing conditions of the page to be connected to the existing page are the same this time, this page (fourth page) is directly connected to the print waiting list (see FIG. 4).
(4) Processing of next page (third page) Since the processing surface attribute of the third page is front (odd page), the page is connected to the print waiting preparation list. Then, after linking, the number of pages linked to the print waiting preparation list is obtained.
Since the engine assumed this time is capable of feeding two sheets on the conveyance path, the print waiting preparation list is a list that can hold up to the number of pages obtained by subtracting 1 from the number of sheets. (2-1 = 1) (See the upper part of FIG. 5)
Here, the reason will be described below. The print waiting preparation list has a role of temporarily evacuating the front page, and by using this, the back page can be continuously connected to the print waiting list. In order to arrange two back-side pages in the print waiting list as in this case, the length of the print ready list is one page at the maximum.
However, when the third page is connected, there are two pages connected to the print waiting preparation list. Since this exceeds the maximum number of pages that can be connected to this list, the following processing is performed.
The first page (first page) of the print waiting list is cut off, and this page is connected to the end of the print wait list (see the middle part of FIG. 5). As a result, the first to fourth pages are connected to the print waiting list in the optimum print order (see the lower part of FIG. 5).
As described above, since the number of pages that can be connected to the print waiting preparation list can be changed, it is possible to cope with changes in the length of the paper transport path.
[0010]
(5) Processing of next page (6th page) The same process as the 4th page is linked to the print waiting list (see FIG. 6).
(6) Process of the last page (5th page) The process is linked to the print waiting list by the same process as the 3rd page (see FIG. 7).
With the above processing, it is possible to realize a printing order that can maximize the performance of the engine. The CPU 3 prints in the order of the print waiting list, and when there are no more pages in the print waiting list, it is only necessary to print the page connected to the print waiting preparation list, which is unrelated to timing control that requires a print waiting state. .
As described above, according to the present invention, the print page order is changed according to various conditions of the data to be printed, and the print print mode is automatically changed. Thus, unlike the conventional method (Patent No. 2879933) in which the print execution / print wait state is created independently depending on the surface attributes of the print page, the present invention has two print wait lists, and the print page is stored in these pages. By simply arranging them in the list, you can print without waiting to print, increasing the duplex printing speed and realizing the maximum productivity of the engine.
[0011]
Next, a process for realizing the printing order when the printing conditions change during duplex printing (second embodiment) will be described with reference to FIG.
This printing uses the engine used in the previous embodiment, and prints 6 pages and 3 sheets of paper. However, for example, it is assumed that a command with a different paper size is sent from the host computer 9 and the paper size of the third sheet (5th and 6th pages) is different from other papers.
Here, the processing from the first page to the fourth page of (1) to (4) is the same as that in the previous embodiment, and the description thereof is omitted.
(5) Processing of the sixth page Since the sixth page is a back page, it aims to be linked to the print waiting list as before. When connecting, the printing conditions of the last page of the print waiting list and the page to be connected (page 6) are compared. Since the paper sizes are different this time, all pages in the print ready list are transferred to the print wait list before the sixth page is connected to the print wait list (see the upper part of FIG. 8). The reason is as follows.
If the print conditions change, the engine cannot print pages without different settings without setting, so the CPU 3 notifies the engine of the changed contents before printing the changed pages and changes the engine settings. There is a need to.
During duplex printing, many engines cannot change settings until there is no more paper on the transport path. Therefore, the CPU 3 needs to change the printing order so as to preferentially print the page on the paper currently being printed, and to set the engine in a state where the setting can be changed as early as possible. In order to realize such a process, before connecting a new page with different printing conditions to the print waiting list indicating the substantial printing order, the presence or absence of a page in the print waiting preparation list is confirmed. Adds these pages to the print waiting list before concatenating new pages. Thereafter, the sixth page with different printing conditions is added to the print waiting list. (Refer to the middle of Fig. 8)
As a result, no paper remains on the conveyance path of the engine before the sixth page is printed, so that the engine can receive a new setting from the CPU 3.
[0012]
(6) Processing of the fifth page Since the fifth page is the front page, it is linked to the print waiting preparation list in the same procedure as in the previous embodiment. (See the lower part of Fig. 8)
By executing such processing, even when the printing order changes during double-sided printing, it is possible to perform printing control that maximizes engine performance.
Even when the thickness of the sheet changes, the CPU 3 notifies the image forming apparatus of the setting change in the same manner as this procedure, and controls the print order by switching the page order in the print waiting list to be connected. .
In addition, even when switching from double-sided printing to single-sided printing, the CPU 3 notifies the image forming apparatus of a setting change in the same manner as this procedure, and controls the printing order by switching the page order in the print waiting list to be connected. To do.
The double-sided printing control operation of the above-described embodiment is summarized as an operation flowchart as shown in FIG.
That is, when this double-sided printing control operation is started, as shown in step 101 of FIG. 9, the surface attribute of the page requested for printing from the CPU 3 is determined. It is determined whether or not there is a list, that is, whether or not the list is empty. If the list is empty in step 103, the page is linked to the end of the print waiting list in step 109. If the list is not empty in step 103, the page and the pages in the list are checked in step 105. The printing conditions are compared.
If the printing conditions of the page and the pages in the list match in step 105, the page is linked to the end of the print waiting list in step 109. If the printing conditions do not match, printing is executed in step 107. All pages linked to the waiting list are linked to the print waiting list, and in step 109, the page is linked to the end of the print waiting list.
In step 101, if the page attribute of the page is front, the page is linked to the end of the print waiting preparation list in step 111. In step 113, the number of pages in the print waiting preparation list falls within an allowable range. It is determined whether or not it exceeds the allowable range. If the allowable range is exceeded, the first page of the print waiting preparation list is linked to the end of the print waiting list in step 115.
[0013]
Next, processing (third embodiment) when there is no consumable during double-sided printing will be described with reference to FIGS. Here, FIG. 10 is an explanatory diagram of the processing when the consumable end is reached during printing of the second page, and FIG. 11 is the processing when the consumable end is reached during printing of the second page. It is a flowchart.
In this printing, the engine used in the previous embodiment is used, and when 4 pages and 2 sheets of paper are printed, it is assumed that there is no consumable during printing of the 2nd page. When there is no consumable item, the image printing apparatus prints only the pages remaining in the double-sided tray, and printing from the normal tray is prohibited. The CPU 3 switches the print page order so as to satisfy this engine restriction.
(1) In order to leave only the print-started pages in the print wait list, the back page (even page) in the state before starting printing is searched from the print wait list (see the upper part of FIG. 10 and steps 201 and 203 in FIG. 11).
If no back page (even page) is found, the print waiting preparation list is searched (see steps 205 and 207 in FIG. 11). If there is a page in the print waiting preparation list, the first page of the print waiting preparation list is displayed. Link to the end of the print waiting list (see the lower part of FIG. 10 and step 209 of FIG. 11).
In addition, when a back page (even page) is found, it progresses to (2).
(2) A front page (odd page) paired with the pre-print start page found in the process of (1) is searched from both the print wait list and the print wait preparation list,
Remove both found front and back pages from their respective lists. (See the middle part of FIG. 10 and steps 211 and 213 of FIG. 11)
By such a process, when the consumables are exhausted, the printing from the example with both sides already under printing and the printing from the normal tray is suppressed. This process is used not only when the consumables end but also when there is no paper.
The present invention can also be applied when various printing conditions such as the following are changed. Hereinafter, modified examples in the case where the printing conditions are variously changed will be described.
That is, when double-sided printing order is changed according to the length of the conveyance path of the paper and optimal double-sided printing is performed, or when the image forming apparatus 1 performs color printing, the print data connected to the print waiting list has. It is also possible to control the printing order by switching the page order in the connected print waiting list depending on the color difference.
Depending on the owner of the print job (difference in user ID), the page order in the print waiting list to be connected can be switched to control the print order, or it can be connected depending on the state of no paper to be printed that occurs during printing. It is also possible to control the printing order by switching the page order in the print waiting list.
[0014]
【The invention's effect】
As can be understood from the above description, according to the present invention, in the image forming apparatus capable of double-sided printing, the printing order and the print waiting list are automatically switched based on various conditions of the page. Therefore, even if the page has different conditions, the double-sided printing mode of the engine can be effectively selected, and the double-sided printing speed can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration block diagram of an embodiment of an image forming apparatus according to the present invention.
FIG. 2 is an explanatory diagram of a printing order determination sequence in double-sided printing in the first embodiment of the image forming apparatus according to the present invention, and shows addition to the list of the second page.
FIG. 3 is an explanatory diagram of a printing order determination sequence in double-sided printing in the first embodiment of the image forming apparatus according to the present invention, and shows addition to the list of the first page.
FIG. 4 is an explanatory diagram of a printing order determination sequence in double-sided printing in the first embodiment of the image forming apparatus according to the present invention, and shows addition to the list of the fourth page.
FIG. 5 is an explanatory diagram of a printing order determination sequence in double-sided printing in the first embodiment of the image forming apparatus according to the present invention, and shows addition to the list on the third page.
FIG. 6 is an explanatory diagram of a printing order determination sequence in double-sided printing in the first embodiment of the image forming apparatus according to the present invention, and shows addition to the list on the sixth page.
FIG. 7 is an explanatory diagram of a printing order determination sequence in double-sided printing in the first embodiment of the image forming apparatus according to the present invention, and shows addition to a list on the fifth page.
FIG. 8 is an explanatory diagram of a printing order determination sequence in double-sided printing in the second embodiment of the image forming apparatus according to the present invention, and shows processing when the paper size is different from the sixth page.
FIG. 9 is a flowchart of a printing order determination sequence in duplex printing in the first embodiment of the image forming apparatus according to the present invention.
FIG. 10 is an explanatory diagram of a printing order determination sequence in double-sided printing in the third embodiment of the image forming apparatus according to the present invention, and shows processing when a consumable end is reached during printing of the second page.
FIG. 11 is a flowchart of a printing order determination sequence in duplex printing in the third embodiment of the image forming apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 3 ... CPU, 5 ... ROM, 7 ... RAM, 9 ... Host computer, 13 ... Memory, 15 ... Image forming part

Claims (7)

An image forming apparatus having an interleaf function capable of holding N sheets of paper on a conveyance path and performing double-sided printing of a pair of front and back print data,
A print waiting list in which the print data for the back side is sequentially stored from the top of the list in the order of input;
Front side print data is sequentially stored from the top of the list in the order of input, and when the back side print data is stored in succession in the print waiting list, the front side print data is stored at the top A waiting list for printing to move to the end of the waiting list for printing;
Control means for executing printing in the order stored in the print waiting list,
If there is no consumable during printing of the back side print data, except for the front side print data that is paired with the back side print data, other print data is transferred from the print wait list and print wait preparation list. An image forming apparatus, wherein the image forming apparatus is deleted.   2. The image forming apparatus according to claim 1, wherein optimal double-sided printing is performed by changing a double-sided printing order according to the length of the conveyance path.   2. The image forming apparatus according to claim 1, wherein the print order is controlled by switching the page order in the print wait list to be connected depending on the color difference of the print data connected to the print wait list.   2. The image forming apparatus according to claim 1, wherein the order of printing is controlled by switching the order of pages in the print waiting list to be connected according to the size of the printing paper.   2. The image forming apparatus according to claim 1, wherein the order of printing is controlled by switching the order of pages in the print waiting list to be connected according to the thickness of the printing paper.   The image forming apparatus according to claim 1, wherein the print order is controlled by switching the page order in the print waiting list to be connected depending on the owner of the print job.   The image forming apparatus according to claim 1, wherein when one-sided printing is requested during double-sided printing, the printing order is controlled by switching the page order in the print waiting list to be connected.

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