JP2010002798A - Image forming apparatus and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform double-sided printing, in response to a double-sided printing requirement at high speed, when successively receiving two double-sided printing requirements in which size or direction of paper is set so as to be different from each other. <P>SOLUTION: Even when the size or direction of the paper designated, by designating information included respectively in the two double-sided printing requirements received successively is different from each other, if a high-speed double-sided printing method corresponding to the size or direction of the paper designated by the designating information is common to them, the common high-speed double-sided printing method is selected, and high-speed double-sided printing, in response to the two double-sided printing requirements, is successively performed in accordance with the selected common high-speed double-sided printing method. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, or a multifunction peripheral having a duplex printing function, and a program for causing a computer to execute a printing control method.

  Currently, image forming apparatuses such as copying machines, printers, and multifunction machines having a double-sided printing function are widely used. The duplex printing methods for realizing the duplex printing function include normal duplex printing and high-speed duplex printing.

  Normally, double-sided printing is a method of completing double-sided printing for each sheet of paper by continuously performing printing on one side of one sheet and printing on the other side of the one sheet. For example, in normal duplex printing, the image of the second page is first printed on the back surface (first printing surface) of the first sheet, and then the image of the first page is printed on the front surface (rear printing surface) of the first sheet. Next, double-sided printing is performed by printing the fourth page image on the back side of the second sheet, and then printing the third page image on the front side of the second sheet.

  On the other hand, high-speed double-sided printing is performed by printing on one side or other side of another sheet between printing on one side of one sheet and printing on the other side of the one sheet. Is a method of performing double-sided printing in parallel. For example, in high-speed duplex printing, the second page image is printed on the back side of the first sheet, the fourth page image is printed on the back side of the second sheet, and then the first sheet is printed. Print the first page image on the front side of the paper, then print the sixth page image on the back side of the third sheet, and then print the third page image on the front side of the second sheet. Then, double-sided printing is performed by printing the eighth page image on the back side of the fourth sheet and then printing the fifth page image on the front side of the third sheet.

  In the example of the high-speed double-sided printing, between the printing on the back side of one sheet and the printing on the front side of the one sheet, printing on the surface of the sheet one sheet before the one sheet, This is a method of sequentially performing printing on the back side of the sheet after one sheet. In addition to the printing on the back side of one sheet and the printing on the front side of the one sheet, the high-speed printing includes printing on the surface of the sheet two sheets before the one sheet, Various methods, such as printing on the back side of the sheet after the first sheet, printing on the front side of the sheet before the one sheet, and printing on the back side of the sheet after the second sheet of the one sheet, etc. is there.

  According to high-speed double-sided printing, the operation period in which the reverse side and the front side of the paper are conveyed to the printing engine are overlapped with the operation period in which printing is performed on the back side or the front side of the paper. Double-sided printing can be performed at high speed.

  On the other hand, the image forming apparatus can usually perform printing on a plurality of different sizes of paper such as A4 size and B5 size.

  Some image forming apparatuses can perform both printing on portrait paper and printing on landscape paper by changing the orientation of the paper supplied to the print engine. In such an image forming apparatus, for example, printing is performed on A4 size paper in portrait orientation by supplying the paper in a portrait orientation from a paper feed cassette that stores A4 size paper in portrait orientation. On the other hand, printing is performed on the landscape-oriented A4 size paper by supplying the paper to the print engine in the landscape orientation from a paper feed cassette that stores the A4-size paper in the landscape orientation.

  By the way, the image forming apparatus continuously receives two jobs to be printed on both sides (double-sided printing job), and among these two jobs, the size and orientation of the paper designated by one job and the other job. When the size and orientation of the paper designated by the above are the same, the conventional image forming apparatus continuously performs high-speed duplex printing based on one job and high-speed duplex printing based on the other job. As a result, printing based on two continuously received duplex printing jobs can be performed at high speed as a whole.

  The reason why high-speed double-sided printing is high-speed is that the back side and the front side of the paper are reversed and transported to the print engine (paper reversal transport operation period), and the back side or front side of the paper is printed (printing operation) Time period). In order to realize this, when performing high-speed double-sided printing, the paper on which printing on the back surface has been completed is accumulated on the paper transport path.

  When performing high-speed duplex printing continuously based on two received duplex printing jobs in succession, high-speed duplex printing based on one job and high-speed duplex printing based on the other job are combined into one job. Performs continuously in the same manner as performing high-speed double-sided printing. That is, in this case, when shifting from high-speed double-sided printing based on one job to high-speed double-sided printing based on the other job, sheets related to high-speed double-sided printing based on one job are accumulated on the paper transport path, Begin printing on paper for high-speed duplex printing based on the other job. Thus, the overlap between the paper reversal conveyance operation period and the printing operation period is maintained during the transition from high-speed double-side printing based on one job to high-speed double-side printing based on the other job. As a result, printing based on two double-sided print jobs received in succession becomes faster overall.

  However, the conventional image forming apparatus continuously receives two jobs indicating that double-sided printing is to be performed, and among these two jobs, the paper size or orientation designated by one job and the other job designate. When the paper sizes or orientations are different from each other, the conventional image forming apparatus does not continuously perform high-speed duplex printing based on one job and high-speed duplex printing based on the other job. That is, in this case, the conventional image forming apparatus once completes the high-speed double-sided printing based on one job and then starts the high-speed double-sided printing based on the other job. For this reason, in this case, when shifting from high-speed double-sided printing based on one job to high-speed double-sided printing based on the other job, the overlap between the paper reversal conveyance operation period and the printing operation period is lost. As a result, the overall printing speed based on the two double-sided print jobs received in succession cannot be increased.

  This problem causes a problem that when the image forming apparatus continuously receives a large number of double-sided printing jobs having different paper sizes or orientations, the effect of speeding up printing by high-speed double-sided printing is not sufficiently exhibited.

  The present invention has been made in view of, for example, the above-described problems, and an object of the present invention is to perform double-sided printing when a plurality of double-sided printing requests having different paper sizes or orientations are successively received. An object of the present invention is to provide an image forming apparatus and a computer program that can perform double-sided printing according to demand at high speed.

  In order to solve the above-described problems, an image forming apparatus according to the present invention includes a printing mechanism capable of performing duplex printing on a plurality of sheets having different sizes or orientations, and a size or orientation of a sheet on which duplex printing is to be performed. A double-sided printing method for receiving a double-sided printing request including designation information for designating and a double-sided printing method corresponding to the size or orientation of the paper designated by the designation information included in the double-sided printing request received by the printing request receiving unit And a printing control means for controlling the printing mechanism in accordance with the selected duplex printing method, wherein the printing control means is included in each of the plurality of duplex printing requests successively received by the printing request receiving means. Even if the paper size or orientation specified by the specification information is different from each other, the paper size or orientation specified by the specification information If the double-sided printing methods corresponding to the two are common to each other, the common double-sided printing method is selected, and the double-sided printing corresponding to the plurality of double-sided printing requests is continuously performed according to the selected common double-sided printing method. Do.

  In the image forming apparatus of the present invention, the print control means performs the double-sided printing according to the first double-sided printing request received by the print request receiving means, while the print request receiving means performs the first printing. The double-sided printing method corresponding to the size or orientation of the paper designated by the designation information included in the second double-sided printing request received successively in the first double-sided printing request is selected, and this double-sided printing method is the first double-sided printing method. If the double-sided printing method of the double-sided printing currently performed in response to the double-sided printing request is common, the double-sided printing according to the first double-sided printing request is performed by continuing the double-sided printing operation currently performed. It is desirable to continuously perform double-sided printing in response to the second double-sided printing request.

  In the image forming apparatus according to the present invention, the duplex printing method includes printing on one side surface or another side surface of another sheet between printing on one side surface of the one sheet and printing on the other side surface of the one sheet. By performing the above, it is desirable that the high-speed duplex printing method performs duplex printing in parallel on two or more sheets.

  In order to solve the above-described problems, a computer program according to the present invention receives a double-sided print request including designation information for designating the size or orientation of a sheet on which double-sided printing is to be performed, and the print request receiving step receives the double-sided print request. Select the duplex printing method that corresponds to the size or orientation of the paper specified by the specified information included in the specified duplex printing request, and perform duplex printing on multiple sheets of different sizes or orientations according to the selected duplex printing method. A program for causing a computer to execute a print control method comprising a print control step for controlling a print mechanism capable of performing printing, wherein the program is received continuously in the print request receiving step. The size or orientation of the paper specified by the specified information included in each two-sided printing request Even if the double-sided printing method corresponding to the paper size or orientation specified by the designation information is common to each other, the common double-sided printing method is selected and the selected common double-sided printing method is selected. In accordance with a printing method, duplex printing based on the plurality of duplex printing requests is continuously performed.

  According to the present invention described above, even when the size or orientation of the paper designated by the designation information included in each of the plurality of continuously received double-sided print requests is different from each other, the paper designated by these designation information If the double-sided printing method corresponding to each size or orientation is a common high-speed double-sided printing method, the common high-speed double-sided printing method is selected, and the plurality of the above-described multiple high-speed double-sided printing methods High-speed duplex printing is continuously performed in response to duplex printing requests. Therefore, even when a double-sided printing request indicating that a plurality of double-sided printings with different paper sizes or orientations should be performed is received, double-sided printing according to these double-sided printing requests can be performed at high speed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of an image forming apparatus of the present invention. As shown in FIG. 1, the image forming apparatus 1 is, for example, a multifunction machine having a copying function and a printer function, and includes a document reading mechanism 11, a printing mechanism 12, a control unit 13, an operation unit 14, a communication interface 15, and a storage unit. 16 is provided.

  The document reading mechanism 11 is a mechanism for reading a document, and is provided on the upper part of the image forming apparatus 1. The printing mechanism 12 prints an image of a document read by the document reading mechanism 11 or an image related to print data transmitted from a terminal device (not shown) such as a personal computer connected to the image forming apparatus 1 so as to be communicable. A mechanism for printing on one or both of the front surface and the back surface of P, and is provided inside the image forming apparatus 1. Further, the printing mechanism 12 can perform double-sided printing on a plurality of sheets P having different sizes or orientations. The control unit 13 is a unit that controls the document reading mechanism 11, the printing mechanism 12, and the like, and is provided inside the image forming apparatus 1. The operation unit 14 is provided on the front panel unit of the image forming apparatus 1 and includes buttons and a small display for the user to operate the image forming apparatus 1. The communication interface 15 is provided inside the image forming apparatus 1 and includes a communication circuit for connecting the image forming apparatus 1 and the terminal device so that they can communicate with each other. The storage unit 16 is configured by a nonvolatile storage device or storage element that can hold information such as a hard disk and a flash memory for a long period of time.

  The printing mechanism 12 rotates the transport roller 21 to transport the paper P stored in the paper feed cassette 22 along the paper transport path 23 formed inside the image forming apparatus 1 and print the paper P. A paper transport mechanism 28 that sequentially supplies the engine 24, the transfer unit 25, and the fixing unit 26, and discharges the paper P that has been printed by the print engine 24, the transfer unit 25, and the fixing unit 26 from the discharge unit 27. .

  Further, the paper transport mechanism 28 includes a double-sided printing unit 31 for performing double-sided printing. The duplex printing unit 31 has a structure suitable for realizing high-speed duplex printing (see FIGS. 5 and 6) for performing duplex printing on two or three sheets of paper P in parallel. That is, the duplex printing unit 31 includes a branching section 32, a sheet transport path 33 for duplex printing, an intermediate tray 34, a switchback mechanism 35, a sheet reversing device 36, and the like. The branching unit 32 is disposed between the sheet discharge side of the fixing unit 26 and the discharge unit 27, and guides the sheet P to the sheet conveyance path 33 of the duplex printing unit 31. The intermediate tray 34 is disposed in the middle of the paper transport path 33 and temporarily accumulates the paper P guided by the branching unit 32. The switchback mechanism 35 reverses the transport direction of the paper P accumulated in the intermediate tray 34 and guides the paper P to the paper transport path 33 again. The sheet reversing device 36 reverses the surface of the sheet P guided to the sheet transport path 33 by the switchback mechanism 35 and supplies the sheet P to the print engine 24. The double-sided printing unit 31 can use a known configuration related to double-sided printing.

  Further, the image forming apparatus 1 has a plurality of paper feed cassettes 22, and each of the paper feed cassettes 22 stores a plurality of types of paper P having different sizes or orientations. Although only three paper feed cassettes 22 are shown in FIG. 1, the image forming apparatus 1 can include a larger number of paper feed cassettes.

  FIG. 2 shows the internal structure of the control unit 13. As shown in FIG. 2, the control unit 13 includes a CPU (Central Processing Unit) 41, a ROM (Read Only Memory) 42, and a RAM (Random Access Memory) 43. The ROM 42 stores a computer program for causing the control unit 13 to function as a job receiving unit 45 and a print control unit 46 described later. The CPU 41 reads out this computer program from the ROM 42 and executes it, thereby causing the control unit 13 to function as the job receiving unit 45 and the print control unit 46. The RAM 43 is used as a working memory when the CPU 41 executes this computer program.

  The job receiving unit 45 receives a job input by the user by operating the operation unit 14 or transmitted from the terminal device, and stores the received job in the RAM 43. The job receiving unit 45 is a specific example of a print request receiving unit.

  There are single-sided print jobs and double-sided print jobs. The single-sided print job is a job indicating that single-sided printing should be performed, that is, a job indicating that printing should be performed only on the surface of the paper P. On the other hand, the double-sided printing job is a job for performing double-sided printing, that is, a job for performing printing on the front and back surfaces of the paper P. Note that the duplex printing job is a specific example of a duplex printing request.

  The job includes designation information for designating the size and orientation of the paper P to be printed. The size and orientation of the paper P will be described later with reference to FIG.

  The print control unit 46 controls the printing mechanism 12 and the like according to the job received by the job receiving unit 45. The print control unit 46 includes a control command unit 46A and a control execution unit 46B. The control command unit 46A selects a printing method (single-sided printing, normal double-sided printing, first high-speed double-sided printing, second high-speed double-sided printing) to control the printing mechanism 12 to perform printing, and selects the selected printing method. A command to the effect that printing should be performed is sent to the control execution unit 46B. The control execution unit 46B controls the printing mechanism 12 and the like according to a command sent from the control command unit 46A, and executes printing according to the printing method selected by the control command unit 46A.

  The case where the job receiving unit 45 receives a double-sided print job will be described in detail. The control command unit 46A determines the size and orientation of the paper P designated by the designation information included in the double-sided print job received by the job receiving unit 45. Is selected, and a command to the effect that duplex printing should be performed in accordance with the selected duplex printing method is sent to the control execution unit 46B. The control execution unit 46B controls the printing mechanism 12 and the like according to the command sent from the control command unit 46A, and performs duplex printing according to the duplex printing method selected by the control command unit 46A.

  The control command unit 46A may specify the designation information even when the sizes or orientations of the sheets P designated by the designation information included in the plurality of double-sided printing requests successively received by the job receiving unit 45 are different from each other. If the high-speed double-sided printing method corresponding to the size and orientation of the paper P specified by each other is common to each other, the common high-speed double-sided printing method is selected, and the plurality of the high-speed double-sided printing methods are selected according to the selected common high-speed double-sided printing method. A command indicating that high-speed double-sided printing corresponding to the double-sided printing request should be continuously performed is sent to the control execution unit 46B. In accordance with this command, the control execution unit 46B controls the printing mechanism 12 and the like, and continuously performs high-speed duplex printing according to the common high-speed duplex printing method selected by the control command unit 46A. The print control unit 46 is a specific example of a print control unit. Details of the job receiving unit 45 and the print control unit 46 will be described later with reference to FIG.

  FIG. 3 shows a print control table. In the print control table 51, the correspondence between the size and orientation of the paper P and the duplex printing method is recorded. Specifically, the correspondence between the identification number assigned for each combination of the size and orientation of the paper P and the identification number assigned for each duplex printing method is recorded. For example, the identification number 11 (A4 landscape) of the size and orientation of the paper P and the duplex printing method identification number 2 (second high-speed duplex printing method) are in a correspondence relationship. The control command unit 46A of the print control unit 46 follows the correspondence between the size and orientation of the paper P recorded in the print control table 51 and the duplex printing method, and the size of the paper P specified by the designation information included in the duplex printing job. And select the duplex printing method corresponding to the orientation. For example, the control command unit 46A selects the second high-speed duplex printing method when the size and orientation of the paper P designated by the designation information included in the duplex printing job is A4 landscape. The print control table 51 is stored in the storage unit 16, for example.

  4 to 7 show four double-sided printing methods, respectively. The double-sided printing method is a method for printing on the front and back surfaces of the paper P. FIG. 4 shows normal duplex printing. Ordinary duplex printing is a method of performing printing on the front and back surfaces of the paper P at a normal speed. In normal double-sided printing, double-sided printing is completed for each sheet of paper by continuously performing printing on the back side of one sheet and printing on the front side of the one sheet. That is, in normal double-sided printing, as shown in FIG. 4, first, the image of the second page is printed on the back surface (first printing surface) of the first sheet P, and then the front surface (rear side) of the first sheet P. The first page image is printed on the printing surface), the fourth page image is printed on the back side of the second sheet P, and then the third page image is printed on the front side of the second sheet P. Double-sided printing is performed according to the printing procedure.

  5 to 7 show three types of high-speed duplex printing, respectively. High-speed duplex printing is a method of performing printing on the front and back surfaces of the paper P at a higher speed than normal duplex printing. In high-speed duplex printing, printing is performed on two or more sheets in parallel by printing on the back or front of another sheet between printing on the back of one sheet and printing on the front of the one sheet. Perform double-sided printing.

  FIG. 5 shows the first high-speed duplex printing. The first high-speed duplex printing is high-speed duplex printing in which duplex printing is performed on two sheets of paper P in parallel. In this high-speed double-sided printing, two sheets are printed by performing printing on the front surface of the previous sheet or the back surface of the next sheet between printing on the back surface of one sheet and printing on the front surface of the one sheet. Double-sided printing is performed on the same paper in parallel. That is, in this high-speed duplex printing, as shown in FIG. 5, the second page image is first printed on the back side of the first sheet P, and then the fourth page image is printed on the back side of the second sheet P. Next, the image of the first page is printed on the surface of the first sheet P, the image of the third page is printed on the surface of the second sheet P, and then the third sheet Double-sided printing is performed by a procedure such as printing an image of the sixth page on the back surface of the paper P.

  FIG. 6 shows the second high-speed duplex printing. The second high-speed duplex printing is high-speed duplex printing in which duplex printing is performed on three sheets of paper P in parallel. In this high-speed double-sided printing, three sheets are printed by performing printing on the front surface of the previous sheet and the back surface of the subsequent sheet between printing on the back surface of one sheet and printing on the front surface of the one sheet. Double-sided printing is performed on the same paper in parallel. That is, in this high-speed double-sided printing, as shown in FIG. 6, the second page image is first printed on the back surface of the first sheet P, and then the fourth page image is printed on the back surface of the second sheet P. Next, the first page image is printed on the front surface of the first sheet P, then the sixth page image is printed on the back side of the third sheet P, and then the second sheet Double-sided printing is performed by printing the third page image on the front side of the paper P and then printing the sixth page image on the back side of the third paper P. According to the second high-speed double-sided printing, double-sided printing can be performed at a higher speed than the first high-speed double-sided printing shown in FIG.

  FIG. 7 shows a third high-speed duplex printing. The third high-speed double-sided printing is high-speed double-sided printing that performs double-sided printing on five sheets of paper P in parallel. In this high-speed double-sided printing, between the printing on the back side of one sheet and the printing on the front side of the one sheet, the front side of the second sheet, the back side of the next sheet, the front side of the previous sheet, and By performing printing on the back side of the second sheet, double-sided printing is performed in parallel on five sheets. That is, in this high-speed double-sided printing, as shown in FIG. 7, the second page image is first printed on the back surface of the first sheet P, and then the fourth page image is printed on the back surface of the second sheet P. Next, the image of the sixth page is printed on the back surface of the third sheet P, the image of the first page is printed on the front surface of the first sheet P, and then the fourth sheet The eighth page image is printed on the back side of the sheet P, the third page image is printed on the front side of the second sheet P, and then the tenth page image is printed on the back side of the fifth sheet P. Is printed, and then double-sided printing is performed by printing the fifth page image on the surface of the third sheet P. According to the third high-speed double-sided printing, double-sided printing can be performed at a higher speed than the second high-speed double-sided printing shown in FIG.

  As described above, three types of high-speed double-sided printing have been described with reference to FIGS. 5 to 7. However, high-speed double-sided printing can be considered other than these. For example, by further increasing the number of sheets to be printed between printing on the back side of one sheet and printing on the front side of the one sheet, high-speed duplex printing that is faster than the above-described high-speed duplex printing is realized. Can do. However, in order to actually realize such high-speed double-sided printing, it is necessary to construct a double-sided printing unit having a structure suitable for performing each high-speed double-sided printing inside the image forming apparatus.

  The image forming apparatus 1 according to the present embodiment includes a duplex printing unit 31 having a structure suitable for performing the first high-speed duplex printing shown in FIG. 5 and the second high-speed duplex printing shown in FIG. 6 (FIG. 1). reference). Therefore, the image forming apparatus 1 according to the present embodiment can perform the first high-speed double-side printing shown in FIG. 5 and the high-speed double-side printing shown in FIG. 6 in addition to the single-side printing and the normal double-side printing shown in FIG.

  FIG. 8 shows the operation of the image forming apparatus 1. As shown in FIG. 8, while the image forming apparatus 1 is in operation, the job receiving unit 45 waits for a job input by the operation of the operation unit 14 by the user or a job transmitted from the terminal device (step S1: Print request receiving process).

  When the job receiving unit 45 receives a job (step S1: YES), the print control unit 46 operates as follows (steps S2 to S10: print control process).

  That is, when the job currently received by the job receiving unit 45 is a single-sided print job (step S2: NO), the control command unit 46A of the print control unit 46 issues a command to perform single-sided printing to the control execution unit 46B. Send to. Subsequently, the control execution unit 46B performs single-sided printing in accordance with the command sent from the control command unit 46A (step S3). The first or second high-speed duplex printing is currently performed by the printing mechanism 12 or the like under the control of the control execution unit 46B based on the duplex printing job received immediately before the job currently received by the job receiving unit 45. If it is in progress, single-sided printing based on the currently received job is performed after completion of the first or second high-speed double-sided printing.

  On the other hand, when the job currently received by the job receiving unit 45 is a double-sided print job (step S2: YES), the control command unit 46A determines the size and orientation of the paper P recorded in the print control table 51 and the double-sided printing method. Are selected, the duplex printing method corresponding to the size and orientation of the paper P designated by the designation information included in the duplex printing job is selected (step S4).

  When the double-sided printing method selected in step S4 is normal double-sided printing (step S5: NO), the control command unit 46A sends a command to the effect of normal double-sided printing to the control execution unit 46B. Subsequently, the control execution unit 46B performs normal duplex printing in accordance with a command sent from the control command unit 46A (step S6). The first or second high-speed duplex printing is currently performed by the printing mechanism 12 or the like under the control of the control execution unit 46B based on the duplex printing job received immediately before the job currently received by the job receiving unit 45. If it is in progress, normal duplex printing based on the currently received job is performed after completion of the first or second high-speed duplex printing.

  On the other hand, when the double-sided printing method selected in step S4 is the first or second high-speed double-sided printing (step S5: YES), subsequently, the control command unit 46A receives the job currently received by the job receiving unit 45. Based on the double-sided print job received immediately before, whether or not the first or second high-speed double-sided printing is currently being performed is checked by the printing mechanism 12 under the control of the control execution unit 46B (step S7). .

  As a result of investigation, when the first or second high-speed double-sided printing is not currently performed (specifically, when printing is not performed, single-sided printing is performed, or normal double-sided printing is performed) (Step S7: NO), the control command unit 46A sends a command to the control execution unit 46B to perform the first or second high-speed double-sided printing selected in Step S4. In accordance with this command, the control execution unit 46B individually performs the first or second high-speed double-sided printing (step S8).

  On the other hand, as a result of the investigation in step S7, when the first or second high-speed double-sided printing is currently being performed (step S7: YES), the control command unit 46A selects the double-sided printing method (first or second) selected in step S4. It is determined whether or not the second high-speed double-sided printing is common to the currently performed high-speed double-sided printing (first or second high-speed double-sided printing) (step S9).

  As a result of this determination, when the duplex printing method selected in step S4 is not common to the currently performed high-speed duplex printing (step S9: NO), the control command unit 46A selects the first or second selected in step S4. Is sent to the control execution unit 46B. In accordance with this command, the control execution unit 46B performs the first or second high-speed double-sided printing (step S8). This high-speed double-sided printing is performed individually after the high-speed double-sided printing currently performed is completed.

  On the other hand, as a result of the determination in step S9, when the double-sided printing method selected in step S4 is common to the currently performed high-speed double-sided printing (step S9: YES), the control command unit 46A causes the job receiving unit 45 to A command to the effect that the high-speed double-sided printing selected in step S4 based on the received double-sided printing job should be performed continuously with the currently performed high-speed double-sided printing is sent to the control execution unit 46B. In accordance with this command, the control execution unit 46B continuously performs high-speed duplex printing (step S10). That is, the control execution unit 46B continues the high-speed double-sided printing operation currently being performed, and performs high-speed double-sided printing based on the double-sided printing job received immediately before the job currently received by the job receiving unit 45, and the job receiving unit 45. To continuously perform high-speed duplex printing based on the currently received duplex printing job.

  For example, the job received immediately before the job currently received by the job receiving unit 45 is a double-sided print job A indicating that four pages of double-sided printing should be performed on the B5 side paper P. If the currently received job is a double-sided print job B indicating that 6-page double-sided printing should be performed on the A4 landscape paper P, the control execution unit 46, as shown in FIG. The second high-speed duplex printing is continuously performed based on these two duplex printing jobs A and B received in succession. In this case, when the printing mechanism 12 shifts from the second high-speed duplex printing based on the duplex printing job A to the second high-speed duplex printing based on the duplex printing job B, the image of the fourth page related to the duplex printing job A is displayed. In the state where the B5 landscape paper P printed on the back side is accumulated in the intermediate tray 34, the second page image related to the duplex printing job B is started to be printed on the back side of the A4 landscape paper P. As a result, during the transition from the second high-speed double-sided printing based on the double-sided printing job A to the second high-speed double-sided printing based on the double-sided printing job B, the overlap between the paper reversal conveyance operation period and the printing operation period is maintained. The As a result, when two second high-speed double-sided printing based on two double-sided printing jobs A and B received in succession perform one second high-speed double-sided printing based on one double-sided printing job As fast as

  In steps S3, S6, S8 and S10, when the transmission of the command from the control command unit 46A to the control execution unit 46B is completed, the processing in the image forming apparatus 1 does not wait for the completion of the print control by the control execution unit 46B. (In parallel with the execution of print control by the control execution unit 46B), the process returns to step S1.

  As described above, according to the image forming apparatus 1, even when the sizes or orientations of the sheets P designated by the designation information included in each of the plurality of continuously received duplex printing jobs are different from each other, If both duplex printing methods corresponding to the paper size and orientation specified by the designation information are common high-speed duplex printing methods, select the common high-speed duplex printing method, and select the selected common high-speed duplex printing method. High-speed duplex printing based on the plurality of duplex printing jobs is continuously performed according to the printing method. Therefore, even when a double-sided print job indicating that a plurality of double-sided printings having different sizes or orientations of the paper P should be performed is received, the double-sided printing based on these double-sided printing jobs can be performed at high speed.

  In FIG. 8 showing the operation of the image forming apparatus 1, the sizes or orientations of the sheets P designated by the designation information included in the two duplex printing jobs received successively by the job receiving unit 45 are different from each other. Even when the double-sided printing method corresponding to the size and orientation of the paper P designated by the designation information is common to each other, the common double-sided printing method is selected and the selected common double-sided printing is selected. Although the case where double-sided printing based on the two double-sided printing jobs is continuously performed according to the method has been described as an example, the present invention is not limited to this. Even when the job receiving unit 45 continuously receives three or more duplex printing jobs, both sides corresponding to the size and orientation of the paper P designated by the designation information included in each of the three or more duplex printing jobs. When the printing methods are common, the common duplex printing method is selected, and duplex printing based on the three or more duplex printing jobs according to the selected common duplex printing method can be continuously performed. .

  In FIG. 8, the high-speed double-sided printing method currently being performed and the currently received high-speed double-sided printing method are being performed while the high-speed double-sided printing based on the job received immediately before the job currently received by the job receiving unit 45 is being performed. When the high-speed double-sided printing method related to the received job is common, the high-speed double-sided printing based on the two jobs received in succession is continuously performed by continuing the high-speed double-sided printing currently performed. Although the case has been described as an example, the present invention is not limited to this. After the job receiving unit 45 receives a plurality of double-sided printing jobs instantaneously and continuously, when the print control unit 46 starts to execute high-speed double-sided printing based on the plurality of double-sided printing jobs, the plurality of double-sided printings are performed. It is determined whether or not the high-speed double-sided printing methods related to the jobs are common to each other.

  Further, in the image forming apparatus 1 described above, even when the sizes or orientations of the sheets P designated by the designation information included in each of the plurality of duplex printing jobs continuously received by the job receiving unit 45 are different from each other. When the duplex printing methods corresponding to the size and orientation of the paper P designated by the designation information are common to each other, the common duplex printing method is selected, and the plurality of the duplex printing methods are selected according to the selected common duplex printing method. Although the case where the double-sided printing based on the double-sided printing job is continuously performed is taken as an example, the present invention is not limited to this. For example, when a plurality of double-sided printing requests having different sizes or orientations of the paper P can be included in one double-sided printing job, a plurality of double-sided printing jobs received by the job receiving unit 45 include a plurality of double-sided printing requests. Even when the size or orientation of the paper P designated by the designation information included in the duplex printing request is different from each other, the duplex printing methods corresponding to the size and orientation of the paper P designated by the designation information are mutually different. If they are common, the common duplex printing method may be selected, and duplex printing corresponding to the plurality of duplex printing requests may be continuously performed according to the selected common duplex printing method.

  In the image forming apparatus 1 described above, the high-speed duplex printing method that can be selected is exemplified by the first high-speed duplex printing method shown in FIG. 5 and the second high-speed duplex printing shown in FIG. The present invention is not limited to this. A third high-speed duplex printing shown in FIG. 7 may be added to the selectable high-speed duplex printing method.

  In the above-described embodiment, the case where the image forming apparatus of the present invention is a multifunction machine having a copying function and a printer function is taken as an example, but the present invention is not limited to this. The present invention can be applied to various apparatuses having a copying machine, a printer, and other double-sided printing functions.

  Further, the present invention can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and an image forming apparatus and a computer program accompanying such a change are also included in the present invention. Included in technical thought.

1 is a partially cutaway view showing an embodiment of an image forming apparatus of the present invention. 2 is a block diagram illustrating an internal structure of a control unit provided in the image forming apparatus according to the embodiment of the present invention. FIG. It is explanatory drawing which shows a printing control table. It is explanatory drawing which shows normal double-sided printing. It is explanatory drawing which shows the high-speed double-sided printing which performs double-sided printing in parallel with respect to two paper. It is explanatory drawing which shows the high-speed double-sided printing which performs double-sided printing in parallel with respect to three paper. It is explanatory drawing which shows the high-speed double-sided printing which performs double-sided printing in parallel with respect to five paper. 3 is a flowchart showing an operation of the image forming apparatus according to the embodiment of the present invention. It is explanatory drawing which shows the high-speed double-sided printing performed continuously based on two double-sided printing jobs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 12 Printing mechanism 13 Control unit 45 Job receiving part (print request receiving means)
46 Print Control Unit (Print Control Unit)
51 Print control table P Paper

Claims (4)

A printing mechanism capable of performing double-sided printing on a plurality of sheets of different sizes or orientations;
A print request receiving means for receiving a double-sided print request including designation information for designating the size or orientation of paper to be printed on both sides;
Print control for selecting a double-sided printing method corresponding to the size or orientation of the paper designated by the designation information included in the double-sided printing request received by the print request receiving unit and controlling the printing mechanism according to the selected double-sided printing method Means and
The print control unit is configured so that the designation information included in the plurality of double-sided print requests successively received by the print request reception unit is different from each other even when the paper sizes or orientations designated by the designation information are different from each other. If the two-sided printing method corresponding to the paper size or orientation specified by each is common to each other, the common two-sided printing method is selected, and the plurality of two-sided printing requests are made according to the selected common two-sided printing method. An image forming apparatus that performs continuous duplex printing continuously.   The print control means continuously performs the first double-sided print request by the print request receiving means while performing double-sided printing according to the first double-sided print request received by the print request receiving means. A duplex printing method corresponding to the size or orientation of the sheet designated by the designation information included in the received second duplex printing request is selected, and this duplex printing method is currently performed in response to the first duplex printing request. If the double-sided printing method is common to the double-sided printing method, the double-sided printing operation corresponding to the first double-sided printing request and the second double-sided printing request are satisfied by continuing the current double-sided printing operation. The image forming apparatus according to claim 1, wherein duplex printing is continuously performed.   In the duplex printing method, two or more sheets are printed by performing printing on one side or the other side of another sheet between printing on one side of the one sheet and printing on the other side of the one sheet. The image forming apparatus according to claim 1, wherein the image forming apparatus is a high-speed double-sided printing method that performs double-sided printing in parallel. A print request receiving step for receiving a double-sided print request including designation information for designating a size or orientation of paper to be printed on both sides;
A duplex printing method corresponding to the size or orientation of the sheet designated by the designation information included in the duplex printing request received in the printing request receiving step is selected, and the sizes or orientations differ from each other according to the selected duplex printing method. A program for causing a computer to execute a printing control method including a printing control process for controlling a printing mechanism capable of performing duplex printing on a plurality of sheets,
In the print control step, even if the sizes or orientations of the sheets designated by the designation information included in each of the plurality of double-sided printing requests successively received in the print request receiving step are different from each other, the designation information If the two-sided printing method corresponding to the paper size or orientation specified by each is common to each other, the common two-sided printing method is selected, and the plurality of two-sided printing requests are made according to the selected common two-sided printing method. A program characterized by performing continuous duplex printing continuously.

Images