JP6696440B2 - Image forming device - Google Patents

Description

  The present invention relates to an image forming apparatus capable of double-sided printing.

  The image forming apparatus includes a multifunction peripheral, a printer, a copying machine, a FAX machine, and the like. Some image forming apparatuses are capable of double-sided printing. The image forming apparatus capable of double-sided printing includes a mechanism for reversing the front and back of paper. Further, a conveyance path (return path) for returning the single-side printed sheet to the image forming unit is provided. The image forming apparatus prints on the unprinted surface of the returned paper. It takes a certain amount of time until the sheet that has passed through the image forming unit is sent back to the image forming unit. Therefore, in double-sided printing, one side of one or a plurality of sheets of paper may be printed while waiting for the arrival of one-sided printed sheets. As a result, the number of sheets printed per unit time in double-sided printing can be increased. An example of such an image forming apparatus is described in Patent Document 1.

  Specifically, in Patent Document 1, two sheets are printed by printing on one side or another side of another sheet between printing on one side of the one sheet and printing on the other side of the one sheet. It is described that two-sided printing is performed on the above papers in parallel (see Patent Document 1: Claim 3).

JP, 2010-002798, A

  Here, the image forming apparatus may be provided with an engine control unit that controls hardware used for printing. The main control unit transmits print setting information regarding the print job to the engine control unit. The print setting information includes various setting values regarding the page to be printed. The main control unit recognizes the setting of the page to be printed. Based on this recognition, the main control unit generates print setting information. For example, at the time of starting a print job, the main control unit transmits the generated print setting information to the engine control unit.

  The engine control unit sets a control target (hardware, device) based on the received print setting information. The engine control unit prints based on the received print setting information. For example, the print setting information includes set values of predetermined print setting items such as paper size and paper orientation. When performing single-sided printing, the print setting information includes a setting value that enables single-sided printing. When performing double-sided printing, the print setting information includes a setting value that enables double-sided printing.

  FIG. 7 is a diagram showing an example of a flow of a conventional normal double-sided printing. The arrows in FIG. 7 indicate the printing order. FIG. 7 shows an example in which four sheets of paper (eight pages in total) are printed on both sides. FIG. 7 shows an example of printing from the back side of the paper.

  FIG. 7 shows the flow of the most common double-sided printing. FIG. 7 shows an example in which one side (back side) of one sheet is printed and then the other side (front side) of the same sheet is printed. In FIG. 7, when the double-sided printing of the previous sheet is completed, the double-sided printing of the next sheet is started. After printing one side of one sheet, the image forming unit waits until the sheet returns. In this case, the time when the image forming unit is not used becomes long. High-speed printing cannot be expected when printing on both sides.

  Note that high-speed double-sided printing (sheet batch printing) may be performed as described in Patent Document 1. In the high-speed double-sided printing, after printing one side (back side) of one sheet, the one side of another sheet is continuously printed before the sheet returns to the image forming unit through the return path. After printing one side of each sheet, the other side is sequentially printed on each sheet returned to the image forming unit. In the high-speed double-sided printing, the number of printed pages of the image forming unit per unit time is increased as compared with the case of FIG. 7.

  Here, the print setting information changes depending on the content (page setting) of the print job to be executed. When the page setting is changed, the main control unit generates new print setting information. The main control unit transmits the newly generated print setting information to the engine control unit. Unless new print setting information is sent, the page (paper) is printed with the settings before the change. However, it takes a certain amount of time to generate and transmit new print setting information and to set hardware in the engine control unit.

  Therefore, if the print setting information is changed during the sheet batch printing, the settlement process is performed. The settlement process is a process in which the sheet batch printing is completed with a predetermined separation sheet, and after the separation sheet is completely printed, the sheet batch printing is restarted.

  For example, when two double-sided print jobs are continuously executed, a settlement process is performed between the print jobs. This is because it cannot be predicted whether the print settings of the previous job and the subsequent job are the same. When two double-sided print jobs are executed consecutively, the delimiter sheet is the last sheet of the preceding double-sided print job. In other words, the delimiter sheet is the last sheet for double-sided printing with the print setting information before the change.

  Also, the page settings may change in the middle of one double-sided print job. In this case, conventionally, if there is even one setting difference, the sheet batch printing settlement process is performed. For example, when the print setting of the page to be printed next and the print setting of the previous sheet (page) are different, the main control unit performs the settlement process. Also in this case, the delimiter sheet is the last sheet to be printed on both sides with the print setting information before the change.

  During the clearing process, the engine control unit does not supply a new sheet of paper after feeding the paper of the sheet of separation until the sheet of paper of the sheet of separation is ejected. The main control unit gives new print setting information to the engine control unit after or until the discharge of the separated sheets. After discharging the separated sheets, the engine control unit restarts the sheet batch printing based on the new print setting information.

  The sheet batch printing is interrupted by the settlement process. For example, when a plurality of double-sided print jobs are continuously executed, the settlement process is performed every time one double-sided print job is completed. If the settlement process is performed, the time during which the image forming unit is not operating becomes long. Due to the settlement process, there is a problem that the printing speed during double-sided printing is reduced.

  In Patent Document 1, high-speed double-sided printing can be continued even if the paper size or orientation is different from the previous page. However, paper size or orientation is only one of many print settings. If the setting values other than the paper size and the paper orientation are different, the settlement process is executed. Therefore, the above problem cannot be solved.

  According to the present invention, sheet batch printing is continued as much as possible to prevent a decrease in printing speed during double-sided printing.

In order to solve the above problems, the image forming apparatus according to claim 1 includes a storage unit, a printing unit, an engine control unit, and a main control unit. The storage unit stores print job data including print content and print settings. The printing unit includes a paper feeding unit that supplies paper, an image forming unit that forms an image on the paper, and a single-sided printed paper that has passed through the image forming unit and returns the paper to the upstream side of the image forming unit. And, including. The engine control unit controls the operation of the printing unit. The main control unit transmits print setting information including set values of a plurality of predetermined print setting items to the engine control unit based on the print job data, and controls the print unit based on the print setting information. The engine control unit is controlled. When performing sheet batch printing in which two or more sheets are continuously printed on both sides based on the print job data including pages for a plurality of sheets stored in the storage unit, the engine control unit sets the one-side continuous printing and the other side printing. The continuous printing is alternately performed by the printing unit. The one-sided continuous printing is printing in which images on one side of a plurality of sheets are continuously formed on the image forming unit. The other-side continuous printing is a printing in which after the one-side continuous printing, a plurality of images on the other side of each sheet returned to the image forming section by the conveyance of the double-sided conveying section are continuously formed on the image forming section. Is. The main control unit, upon receiving the print job data to be one of the double-sided printing, recognizing the difference between the print settings of each page of the two-sided printing. The main control unit confirms whether or not the print settings of all pages of the print job data are the same, and when the print settings of all pages are the same, the main control unit generates one of the print setting information. One piece of print setting information is transmitted to the engine control unit. When the print settings of all pages are not the same, the main control unit generates the plurality of print setting information according to the difference of the print settings, transmits the plurality of print setting information, and then the print unit. Then, the sheet batch printing is started. When receiving the plurality of print setting information, the engine control unit causes the printing unit to print each sheet based on the corresponding print setting information while continuing the sheet batch printing.

  According to the present invention, when double-sided printing is continuously performed on a plurality of sheets, the settlement process is less likely to be performed than in the past. Therefore, it is possible to prevent a decrease in printing speed in double-sided printing.

FIG. 1 illustrates an example of a printer according to an exemplary embodiment. FIG. 1 illustrates an example of a printer according to an exemplary embodiment. It is a figure which shows an example of the computer which concerns on embodiment. It is a figure which shows an example of the post-processing apparatus which concerns on embodiment. It is a figure which shows an example of the sheet batch printing in the printer which concerns on embodiment. 6 is a flowchart illustrating an example of a flow of processing of sheet batch printing in the printer according to the embodiment. It is a figure which shows an example of the flow of the conventional usual double-sided printing.

  The image forming apparatus according to the present invention will be described below with reference to FIGS. In the following description, the printer 100 will be described as an example of the image forming apparatus. However, each element such as the configuration and arrangement described in the present embodiment does not limit the scope of the invention and is merely an example for explanation.

(Outline of image forming apparatus)
First, the printer 100 according to the embodiment will be described with reference to FIGS. 1 to 3. 1 and 2 are diagrams illustrating an example of the printer 100 according to the embodiment. FIG. 3 illustrates an example of the computer 200 according to the embodiment.

  The printer 100 includes a main control unit 1 and a storage unit 2. The main control unit 1 controls the operation of the entire apparatus and controls each unit of the printer 100. The main control unit 1 includes a CPU 11 and an image processing unit 12. The CPU 11 performs calculation and control. The image processing unit 12 performs image processing necessary for printing on the image data. The storage unit 2 includes storage devices such as ROM, RAM, and HDD. The storage unit 2 stores control programs and data.

  The main controller 1 is communicably connected to the operation panel 3. The operation panel 3 includes a display panel 31, a touch panel 32, and hard keys 33. The main controller 1 controls the display on the display panel 31. Further, the main control unit 1 recognizes the operated operation image among the operation images displayed on the display panel 31, based on the output of the touch panel 32. For example, the operation image is a soft key or button. Further, the main control unit 1 recognizes the operated hard key 33. The operation of the user is accepted by the operation image or the operation on the hard key 33. For example, the user can set the discharge destination of the printed paper.

  The printer 100 includes an engine control unit 4 and a printing unit 5. The printing unit 5 includes a paper feed unit 5a, a transport unit 5b, an image forming unit 5c, a fixing unit 5d, and a double-sided transport unit 5e. The engine control unit 4 is communicably connected to the main control unit 1. The main controller 1 gives print setting information and image data used for printing to the engine controller 4. The print setting information includes data indicating a print instruction and the content of a print job (details will be described later).

  Based on the print setting information and image data received from the main control unit 1, the engine control unit 4 controls the printing unit 5 (paper feed unit 5a, transport unit 5b, image forming unit 5c, fixing unit 5d, double-sided transport unit 5e). Control movements. Specifically, the engine control unit 4 feeds the sheets one by one to the sheet feeding unit 5a. The paper feeding unit 5a includes a plurality of paper feeding cassettes 51. At the time of a print job, one of the paper feed cassettes 51 supplies paper. The engine control unit 4 causes the supplied sheet to be transported to the transport unit 5b. The engine control unit 4 causes the image forming unit 5c to form a toner image (image) on the sheet conveyed by the conveying unit 5b, and transfers the toner image to the sheet. The engine control unit 4 fixes the toner image transferred on the paper to the fixing unit 5d. The fixing unit 5d includes a heater 52 for heating the paper.

  As shown in FIG. 2, the image forming unit 5c includes a photosensitive drum 53, a charging device 54, an exposure device 55, a developing device 56, a transfer device 57, and a cleaning device 58. At the time of printing, the engine control unit 4 rotates the photosensitive drum 53. The engine control unit 4 charges the photoconductor drum 53 with the charging device 54. The engine control unit 4 causes the exposure device 55 to scan and expose the photosensitive drum 53. As a result, an electrostatic latent image corresponding to the image data is formed. The engine controller 4 causes the developing device 56 to develop the electrostatic latent image with toner. The engine control unit 4 causes the transfer device 57 to transfer the toner image onto the conveyed paper. The sheet passes between the photoconductor drum 53 and the transfer device 57. The cleaning device 58 removes toner and dirt remaining on the photosensitive drum 53.

  The double-sided transport unit 5e sends back the single-side printed sheet that has passed through the image forming unit 5c and the fixing unit 5d to the upstream side of the image forming unit 5c. During double-sided printing, the engine control unit 4 causes the double-sided transport unit 5e to transport the paper. As shown in FIG. 2, the double-sided transport unit 5e includes a branch unit 59, a first transport unit 510, an intermediate tray 511, a switchback roller pair 512, and a second transport unit 513. The branch portion 59 is disposed between the sheet discharge side of the fixing portion 5d and the discharge roller pair 514. The branch part 59 rotates. The branch portion 59 guides the sheet conveyance direction. When performing double-sided printing, the engine control unit 4 rotates the branching unit 59 so that the single-sided printed sheet is guided to the first transport unit 510. During single-sided printing and when ejecting double-sided printed paper, the engine control unit 4 rotates the branching unit 59 so that the single-sided printed paper is guided to the ejection roller pair 514.

  The first transport unit 510 connects the branch unit 59 and the switchback roller pair 512. The first transport unit 510 is provided with a plurality of first return roller pairs 515. A first motor (not shown) for rotating the first return roller pair 515 is provided. The engine control unit 4 rotates this motor during double-sided printing. A switchback roller pair 512 is provided at one end of the intermediate tray 511. A second motor (not shown) for rotating the switchback roller pair 512 is provided. This second motor can rotate forward and backward. During double-sided printing, the engine control unit 4 rotates the switchback roller pair 512 by the second motor. First, the engine control unit 4 feeds the single-side printed sheet toward the other end of the intermediate tray 511. The engine control unit 4 causes the second motor to rotate in the reverse direction when the trailing edge of the one-side printed sheet has passed through the first transport unit 510. The conveyance direction of the paper printed on one side is reversed.

  The sheet is ejected from the switchback roller pair 512 by the reversal. Then, the single-side printed sheet is sent to the second transport unit 513. The second transport unit 513 connects the switchback roller pair 512 and the transport unit 5b on the upstream side of the image forming unit 5c. The second transport unit 513 is provided with a plurality of second return roller pairs 516. A third motor (not shown) for rotating the second return roller pair 516 is provided. The engine control unit 4 rotates the third motor during double-sided printing. As a result, the sheet whose front and back sides are reversed is sent back to the image forming unit 5c. The engine control unit 4 causes the image forming unit 5c to transfer the toner image to the unprinted surface of the returned single-side printed sheet.

  The communication unit 6 is an interface for communicating with the computer 200 such as a PC or a server. The communication unit 6 communicates with the computer 200 via the network. The communication unit 6 and the computer 200 may be directly communicably connected to each other by using a USB cable or the like. The communication unit 6 receives the print job data D1 from the computer 200. The print job data D1 includes print content and print settings. To receive. The main control unit 1 causes the printing unit 5 to perform printing based on the print job data D1.

  As shown in FIG. 3, the computer 200 includes a processing unit 201 (control board), a storage device 202, a display 203, an input device 204, and a network communication unit 205. The processing unit 201 includes a control circuit such as the CPU 11. The computer 200 also includes a storage device 202. The storage device 202 is a ROM, a RAM, and a HDD. The driver software 206 is installed in the storage device 202. The processing unit 201 uses the driver software 206 to generate print job data D1.

  When the driver software 206 is activated, the processing unit 201 causes the display 203 to display a setting screen regarding printing. For example, the input device 204 is a keyboard or a mouse. The user can make settings related to printing using the input device 204 and the driver software 206. The computer 200 includes a network communication unit 205. The processing unit 201 causes the network communication unit 205 to transmit the print job data D1 generated toward the printer 100 (communication unit 6). The image forming system 300 can be constructed by combining the printer 100 and the computer 200.

(Post-processing device 7)
Next, the outline of the post-processing device 7 according to the embodiment will be described with reference to FIG. FIG. 4 is a diagram illustrating an example of the post-processing device 7 according to the embodiment.

  The post-processing device 7 is a device for performing various types of post-processing on printed paper. The printer 100 can be equipped with the post-processing device 7. The printed sheet that has passed through the fixing unit 5d is discharged from the discharge roller pair 514 (discharge port 101). The post-processing device 7 includes a carry-in port 7a. The printed paper is sent into the post-processing device 7 from the carry-in port 7a.

  As shown in FIG. 3, the post-processing device 7 is provided with an upper discharge tray 71, a first discharge tray 72, a second discharge tray 73, a punch section 74, a staple section 75, and a processing tray section 76. Further, the post-processing device 7 is provided with a post-processing control unit 70 (see FIG. 1).

  The post-processing control unit 70 controls the operation of each unit of the post-processing device 7. The post-processing control unit 70 is a substrate including a processing circuit such as a CPU and a microcomputer and a memory. The engine control unit 4 gives an instruction to the post-processing control unit 70. The post-processing device 7 controls the operation of the post-processing device 7 based on an instruction from the engine control unit 4. In the post-processing device 7, a plurality of sheet-conveying roller pairs 77 are provided. Each roller pair 77 rotates by receiving the driving force of a motor (not shown). The post-processing control unit 70 rotates each roller pair 77 to convey the paper inside the post-processing device 7.

  The upper discharge tray 71 is provided on the upper surface of the post-processing device 7. The first discharge tray 72 is provided above the second discharge tray 73. The second discharge tray 73 is provided below the first discharge tray 72. The discharge destination (the discharge tray to be used) can be set by operating the operation panel 3. The punch unit 74 is a unit that performs a punching process on a sheet. The processing tray unit 76 is a unit for stacking a stack of sheets in units of copies. The stapling section 75 is a section that performs stapling processing on the sheet bundle of the processing tray section 76.

  A first sorting guide 78 and a second sorting guide 79 are provided for sorting the destinations of the sheets in the post-processing device 7. The first sorting guide 78 is provided near the carry-in port 7a. The second sorting guide 79 is provided between the carry-in port 7a and the processing tray section 76. A motor (not shown) is provided for each of the first sorting guide 78 and the second sorting guide 79. Each sorting guide rotates. The post-processing control unit 70 rotates the first sorting guide 78 and the second sorting guide 79 according to the setting of the discharge destination.

  When the sheet is set to be discharged to the first discharge tray 72, the post-processing control unit 70 is configured to move in the conveyance direction toward the first discharge tray 72 after passing through the punch unit 74 (arrow A in FIG. 4). The sorting guide 78 and the second sorting guide 79 are rotated. When the sheet is set to be discharged to the upper discharge tray 71, the post-processing control unit 70 causes the sheet carried in from the carry-in port 7a to be directed upward and discharged to the upper discharge tray 71 (direction B in FIG. 4). 1 The sorting guide 78 is rotated. When the staple processing is set, the post-processing control unit 70 rotates the first sorting guide 78 and the second sorting guide 79 so that the sheet is guided in the direction of the processing tray unit 76 (direction C in FIG. 4). Let The post-processing control unit 70 reversely feeds the bundle of sheets after the stapling process by the stapling unit 75, and discharges the bundle onto the second discharge tray 73 (direction D in FIG. 4).

(Sending print setting information)
Next, the transmission of print setting information by the printer 100 according to the embodiment will be described with reference to FIGS. 1 and 3.

  Various software is used in the computer 200 (PC). The software of the computer 200 includes, for example, word processing documents, spreadsheets, image editing, and the like. In addition, driver software 206 is installed in the computer 200 as software for printing with the printer 100.

  When a print command is input by various software, the driver software 206 operates. The driver software 206 can be set for printing. For example, double-sided printing, single-sided printing, which paper cassette 51 is used, discharge destination, paper type used for printing, weight of paper used for printing, paper size used for printing, paper orientation, You can set the post processing to be executed. The computer 200 generates print job data D1 based on the settings in the driver software 206. The computer 200 includes the print content of the page designated by the driver software 206 in the print job data D1. The print settings (setting contents) made by the driver software 206 are also included in the print job data D1. For example, the print content is data describing the content of each page of the file to be printed in a description language (PDL). The page description language is a language for instructing the printer 100 to draw.

  The storage unit 2 of the printer 100 stores the print job data D1 received from the computer 200. The storage unit 2 can store print job data D1 including pages for a plurality of sheets. The main controller 1 analyzes the print job data D1. Based on the analysis result of the print job data D1, the main control unit 1 determines each set value of a plurality of predetermined print setting items. The print setting items include the type of paper used for printing, the weight of the paper used for printing, the size of the paper used for printing, the need for double-sided printing, the margins of the paper, the color settings, the discharge destination, and post-processing to be executed. Be done. The print setting item is an item for the engine control unit 4 to control the printing unit 5. Further, based on the analysis result, the main control unit 1 (image processing unit 12) generates image data of the page included in the print job data D1.

  Before the printing of the first page is started, the main control unit 1 generates print setting information in which each set value of each print setting item is summarized. The main control unit 1 sends the print setting information to the engine control unit 4. Based on the received print setting information, the engine control unit 4 sets the operations of the paper feed unit 5a, the transport unit 5b, the image forming unit 5c, the fixing unit 5d, the double-sided transport unit 5e, and the post-processing device 7. For example, when the print setting information of the setting for performing double-sided printing is received, the engine control unit 4 causes the printing unit 5 to perform double-sided printing.

(Sheet batch printing)
Next, an example of sheet batch printing by the printer 100 according to the embodiment will be described with reference to FIG. FIG. 5 is a diagram illustrating an example of sheet batch printing in the printer 100 according to the embodiment.

  When the printer 100 continuously performs double-sided printing on a plurality of sheets (when performing sheet batch printing), the main control unit 1 causes the engine control unit 4 to perform sheet batch printing. The engine control unit 4 causes the printing unit 5 to perform sheet batch printing.

  In sheet batch printing, the engine control unit 4 causes the printing unit 5 to alternately perform continuous printing on one side and continuous printing on the other side. Single-sided continuous printing is printing in which images on one side of a plurality of sheets are continuously formed on the image forming unit 5c. After the image forming unit 5c passes through the sheet until the sheet returns to the upstream side of the image forming unit 5c by the double-sided conveyance unit 5e, the engine control unit 4 performs image formation and transfer on one surface of a plurality of sheets. The forming part 5c is performed. In the following description, the number of pages (the number of pages) on which one side is continuously printed in one-sided continuous printing is referred to as a “circulating number”.

  The other-side continuous printing is printing in which after the one-side continuous printing, a plurality of images on the other side of each sheet returned to the image forming section 5c by the conveyance of the double-sided conveying section 5e are continuously formed on the image forming section 5c. .. The other side continuous printing is continued for the same number of pages (circulation number) as the one side continuous printing. The engine control unit 4 causes the image forming unit 5c to perform image formation and transfer to the other surface of the single-side printed sheet returned to the image forming unit 5c by the double-sided conveyance unit 5e.

  The circulation number is determined based on the number of sheets that can be circulated in the printer 100. The longer the sheet in the sheet transport direction is, the smaller the number of circulating sheets is. The shorter the length of paper in the paper transport direction, the greater the number of sheets to be circulated. For example, the transport distance from the image forming unit 5c → fixing unit 5d → double-sided transport unit 5e → transport unit 5b to the confluence is divided by the length in the paper transport direction. The value obtained by dividing the value is rounded down to the nearest whole number, which is taken as the circulation number. A value that is one less than the integer value may be used as the circulating sheet number.

  The circulating sheet number is determined in advance according to the sheet size and orientation. The sheet number data D2, which defines the number of sheets to be circulated according to the sheet size and orientation to be used, is stored in the storage unit 2 (see FIG. 1). The main control unit 1 determines the circulating sheet number based on the sheet used for double-sided printing. The main control unit 1 may send the determined circulation number to the engine control unit 4 as print setting information.

  FIG. 5 shows an example in which sheet batch printing is performed on five sheets. When performing double-sided printing on 5 sheets, the number of pages to be printed is 10. In FIG. 5, the order of pages is illustrated by rectangles with numbers. In double-sided printing, the back page is printed on one side of the paper. After printing one side, the front page is printed on the other side. Therefore, in the example of FIG. 5, printing is started from the second page.

  Further, FIG. 5 shows an example in which the circulating number is three. Therefore, in the example of FIG. 5, printing is continuously performed on one side of three sheets (the order of the second page, the fourth page, and the sixth page). After the one-sided printing of the third sheet is completed, the first sheet returns. The first page is printed on the other surface of the first sheet returned by the double-sided transport unit 5e. Then, the third page is printed on the other surface of the second sheet. Further, the fifth page is printed on the other surface of the third sheet. In this way, the one-side continuous printing of the circulating number and the other-side continuous printing of the circulating number are alternately performed.

  When the other side continuous printing is completed, the one side continuous printing is restarted. In the example of FIG. 5, printing is continuously performed on one side of two sheets of paper (8th page, 10th page). The 10th page is the last page. The seventh page is printed on the other surface of the fourth sheet returned by the double-sided transport unit 5e. Subsequently, the ninth page is printed on the other surface of the fifth sheet. When the total number of printed pages is not divisible by the circulation number, the number of sheets in the last one-side continuous printing (second-side continuous printing) is less than the circulation number.

(Flow of sheet batch printing process)
Next, with reference to FIG. 6, an example of a flow of processing of sheet batch printing in the printer 100 according to the embodiment will be described. FIG. 6 is a flowchart showing an example of the flow of sheet batch printing processing in the printer 100 according to the embodiment.

  The printer 100 receives the print job data D1 from the computer 200. The received print job data D1 is stored in the storage unit 2. The communication unit 6 may receive the print job data D1 including pages for a plurality of sheets. In this case, the storage unit 2 stores print job data D1 including pages for a plurality of sheets.

  When a plurality of pages of print job data D1 set to perform single-sided printing are received, the main control unit 1 causes the engine control unit 4 to continuously perform single-sided printing of a plurality of sheets. The setting is for performing double-sided printing, and when the print job data D1 including pages for a plurality of sheets is received, the main control unit 1 causes the plurality of sheets to be continuously printed for double-sided printing. When the print job data D1 has three or more pages, the main controller 1 performs sheet batch printing. When the print job data D1 includes two pages, the main control unit 1 causes the engine control unit 4 to perform double-sided printing on one sheet.

  When the print job data D1 is set to perform double-sided printing and the print job data includes three or more pages, the main control unit 1 causes the engine control unit 4 (printing unit 5) to perform sheet batch printing. The sheet batch printing is performed based on the print job data D1 for a plurality of sheets (three pages or more) stored in the storage unit 2. In sheet batch printing, double-sided printing is continuously performed on a plurality of sheets of paper.

  Further, in order to continue the sheet batch printing as much as possible, the driver software 206 of the computer 200 can be set so that a plurality of double-sided printing print jobs are put together. The input device 204 of the computer 200 receives an operation to combine a plurality of print jobs into one. For example, the input device 204 of the computer 200 receives selection of a plurality of files (data) created based on software. Further, the input device 204 receives a setting for outputting all selected files by double-sided printing.

  In this case, the processing unit 201 of the computer 200 generates one print job data D1 including each page of each selected file. That is, the processing unit 201 combines a plurality of print jobs to generate one print job data D1. The processing unit 201 causes the network communication unit 205 to transmit the collected data toward the communication unit 6. The communication unit 6 of the printer 100 receives print job data D1 in which a plurality of print jobs are put together. The main control unit 1 stores the print job data D1 in the storage unit 2. When a plurality of pages (three pages or more) are included in the combined print job data D1, sheet batch printing is performed.

  Here, conventionally, when a plurality of double-sided printing jobs are input, the settlement processing is performed between the sheet batch printing jobs. The settlement process is a process for ending the sheet batch printing once. In the clearing process, after the last paper feeding of the preceding double-sided printing job, the paper feeding is not performed until the printing of the paper is completed. After completion of printing the last sheet, sheet batch printing (paper feeding) of the next double-sided printing job is started.

  When a double-sided print job is individually input to the image forming apparatus, the print setting of the next (post) double-sided print job cannot be predicted. Normally, print settings are different for each double-sided print job. The print setting information changes for each print job. The main control unit needs to notify the engine control unit of the changed print setting information. A certain amount of time is required to generate and send print setting information. When the print settings are different, the main control unit needs to notify the engine control unit of the changed print setting information. Therefore, conventionally, when the double-sided print jobs are continuously executed, the settlement process is performed between the double-sided print jobs.

  In addition, print settings may differ between pages included in one print job data D1 for double-sided printing. For example, the paper size may be different. For example, in the print job data D1 including 12 pages, there is a double-sided print job in which 1 to 6 pages (1 to 3 sheets) are A4 size and 7 to 12 pages (4 to 6 sheets) are A3 size. obtain. When the print settings between pages are different, the settlement process is performed even in one print job. In the above example, the settlement process is performed between the third and fourth sheets.

  When the settlement process is performed, sheet batch printing cannot be continued. Therefore, the printing speed during double-sided printing is reduced. In other words, the number of printed sheets per unit time during double-sided printing is reduced. Therefore, the main control unit 1 of the printer 100 continues the sheet batch printing as much as possible.

  The start in FIG. 6 is a setting for performing double-sided printing, and is a time when the print job data D1 including a plurality of pages or more is stored. First, the main controller 1 analyzes the print settings of each page based on the print job data D1 (step # 1). Then, the main controller 1 confirms whether or not the print settings of all pages of the print job data D1 are the same (step # 2).

  When the print settings of all pages are the same (Yes in step # 2), all pages may be printed based on one print setting information. In this case, the main controller 1 generates one print setting information (step # 3). The main controller 1 transmits one piece of print setting information to the engine controller 4 (step # 4). The engine control unit 4 executes sheet batch printing based on one print setting information (step # 5). In the case of step # 5, the settlement process is not performed. Sheet batch printing is not interrupted. Then, this flow ends (step # 5 → end).

  When the print settings of all pages are not the same (No in step # 2), the main control unit 1 generates a plurality of print setting information according to the difference in print settings between pages (step # 6). When a plurality of pieces of print setting information are generated, the main control unit 1 confirms the difference between the setting values of the print setting information (step # 7).

  Then, the main control unit 1 sets different values for one or more of the discharge destination, the printing resolution, the paper type, the weight of the paper, the paper size, and the paper feed cassette 51, but the other setting values are the same. The setting information is extracted (step # 8).

  When a plurality of print setting information cannot be extracted (No in step # 9), the main control unit 1 transmits the print setting information one by one to the engine control unit 4 (step # 10). The engine control unit 4 sequentially completes printing of pages corresponding to the transmitted print setting information (step # 11). Thus, when the printing of the page corresponding to one print setting information is completed, the settlement process is performed. Then, it is confirmed whether or not printing of all pages is completed (step # 12). When printing of all pages is not completed (No in step # 12), the flow returns to step # 10. At this time, the print setting information corresponding to the unprinted page is transmitted. On the other hand, when printing of all pages is completed (Yes in step # 12), this flow ends (end).

  When the plurality of print setting information items can be extracted (Yes in step # 9), the main control unit 1 transmits the plurality of extracted print setting information items to the engine control unit 4 (step # 13). When a plurality of pieces of print setting information are received, the engine control unit 4 causes the printing unit 5 to print each sheet (page) based on the corresponding print setting information while continuing the sheet batch printing (step # 14). The main control unit 1 includes, in each print setting information, information indicating which page corresponds to which print setting information.

  Consider a case where print setting information corresponding to some pages (for example, pages 1 to 4) and print setting information corresponding to pages of other portions (for example, pages 5 to 8) are transmitted. In this case, the engine control unit 4 causes the printing unit 5 to print some pages (1st to 4th pages, the first sheet and the second sheet) based on the print setting information corresponding to some pages. The engine control unit 4 causes the printing unit 5 to print the pages of other parts (pages 5 to 8, the third and fourth pages) based on the print setting information corresponding to the pages of the other parts.

  When the set value of the discharge destination is different, the engine control unit 4 switches the discharge destination to the post-processing control unit 70 during the sheet batch printing.

  When the setting values of the print resolution are different, the engine control unit 4 causes the image forming unit 5c to change the resolution of the toner image during the sheet batch printing. When lowering the print resolution, the engine control unit 4 lowers the resolution of the image data transmitted to the image forming unit 5c. For example, when the print resolution is halved, the engine control unit 4 reduces the frequency (cycle) in which the exposure device 55 scans and exposes the photosensitive drum 53 during the sheet batch printing to ½. As a result, the print resolution is reduced.

  When the set value of the paper type is different, the engine control unit 4 switches the paper type used for printing to the paper feeding unit 5a during the sheet batch printing. There are three types of paper, for example, thick paper, plain paper, and thin paper. The operation panel 3 receives the setting of the type of paper stored in the paper feed cassette 51. Further, the computer 200 may be allowed to set the type of paper stored in the paper feed cassette 51. In this case, data indicating the type of paper in the paper feed cassette 51 is transmitted from the computer 200 to the communication unit 6. The engine control unit 4 recognizes the type of paper stored in each paper feed cassette 51. During the sheet batch printing, the engine control unit 4 causes the paper feeding cassette 51 to feed paper according to the set value of each print setting information.

  When the set value of the paper weight is different, the engine control unit 4 switches the setting of the paper weight used for printing during the sheet batch printing. There are three types of paper weight levels, for example, light, normal, and heavy. For example, the engine control unit 4 increases the output of the heater 52 of the fixing unit 5d (increases the temperature of the fixing unit 5d) as the sheet is heavier. Further, the heavier the paper, the more current may be supplied to each motor that rotates the roller pair that conveys the paper. The roller pair for transporting the sheet includes the transport section 5b, the first transport section 510, the second transport section 513, the switchback roller pair 512, the discharge roller pair 514, and the roller pair 77 in the post-processing device 7. During the sheet batch printing, the engine control unit 4 changes the operation of the printing unit 5 according to the set value of the paper weight of each print setting information.

  When the setting values of the paper size are different, the engine control unit 4 switches the paper size used for printing to the paper feeding unit 5a during the sheet batch printing. The operation panel 3 receives the setting of the size of the paper stored in the paper feed cassette 51. Further, the computer 200 may be allowed to set the size of the paper stored in the paper feed cassette 51. In this case, the setting data indicating the paper size of the paper feed cassette 51 is transmitted from the computer 200 to the communication unit 6. The engine control unit 4 recognizes the size of paper stored in each paper feed cassette 51. During the sheet batch printing, the engine control unit 4 changes the paper feed cassette 51 to be fed according to the set value of each print setting information.

  When the set values of the paper feed cassettes 51 are different, the engine control unit 4 switches the paper feed cassettes 51 used for printing during the sheet batch printing. During the sheet batch printing, the engine control unit 4 changes the paper feed cassette 51 to be fed according to the set value of each print setting information.

  On the other hand, if the setting values of the print setting items other than the discharge destination, the print resolution, the paper type, the weight of the paper, the paper size, and the paper feed cassette 51 are different among the print setting information, the settlement process is performed. For example, when the contents of the post-processing are different, the settlement processing is performed between pages with different print setting information. This is because the wrong page may be stapled or punched.

  In addition, the settlement process is performed even when the set values of the paper transport speed are different between the print setting information. In this case, if sheet batch printing is performed, the sheet conveyance speed may change frequently. Frequent switching of the paper transport speed may affect the image quality. Further, if the paper conveyance speed is frequently changed, the printing speed may be rather lowered.

  When the storage unit 2 stores the print job data D1 set to perform double-sided printing and the print job data D1 set to perform single-sided printing, the main control unit 1 performs the single-sided printing after the double-sided printing. Let's do it. Alternatively, the main control unit 1 causes the engine control unit 4 to perform double-sided printing after single-sided printing.

  After the sheet batch printing is continued based on the plurality of print setting information (after step # 14), the flow shifts to step # 12. The print setting information extracted in step # 8 has already been transmitted to the engine control unit 4. If there is print setting information that has not been sent, the print setting information that has not been sent has the setting values of print setting items other than the discharge destination, print resolution, paper type, paper weight, paper size, and paper cassette 51 already sent. Different from the print setting information of. Therefore, the main controller 1 sends the print setting information to the engine controller 4 one by one.

  In this way, the image forming apparatus (printer 100) according to the embodiment includes the storage unit 2, the printing unit 5, the engine control unit 4, and the main control unit 1. The storage unit 2 stores print job data D1 including print content and print settings. The printing unit 5 supplies a sheet, a sheet feeding unit 5a, an image forming unit 5c that forms an image on the sheet, and a single-side printed sheet that has passed through the image forming unit 5c and returns the sheet to the upstream side of the image forming unit 5c. And a transport unit 5e. The engine control unit 4 controls the operation of the printing unit 5. The main control unit 1 transmits print setting information including setting values of a plurality of predetermined print setting items to the engine control unit 4 based on the print job data D1, and causes the printing unit 5 to operate based on the print setting information. The control unit 4 is controlled. When performing sheet batch printing in which two or more sheets are continuously printed on both sides based on the print job data D1 including pages for a plurality of sheets stored in the storage unit 2, the engine control unit 4 causes the one-side continuous printing and the other side printing. The printing unit 5 is made to alternately perform continuous printing. Single-sided continuous printing is printing in which images on one side of a plurality of sheets are continuously formed on the image forming unit 5c. The other-side continuous printing is printing in which after the one-side continuous printing, a plurality of images on the other side of each sheet returned to the image forming section 5c by the conveyance of the double-sided conveying section 5e are continuously formed on the image forming section 5c. .. The main control unit 1 recognizes the difference in the print settings of each page for double-sided printing, generates a plurality of print setting information according to the difference in the print settings, and transmits the plurality of print setting information to the printing unit 5. Start sheet batch printing. When receiving the plurality of print setting information, the engine control unit 4 causes the printing unit 5 to print each sheet based on the corresponding print setting information while continuing the sheet batch printing.

  This allows the engine control unit 4 to have a plurality of print setting information. The print setting information is given to the engine control unit 4 in advance. Since the changed print setting information is given to the engine control unit 4, it is not necessary to settle the sheet batch printing. Therefore, in the case of double-sided printing, sheet batch printing continues more than before. The printing speed (productivity) during double-sided printing can be maintained at a high level.

  Further, the image forming apparatus has a plurality of discharge destinations for discharging the printed matter. When performing sheet batch printing, when a plurality of print setting information with different set values of the discharge destination is received, the engine control unit 4 switches the discharge destination to discharge based on each print setting information, and performs the sheet batch printing. To the printing unit 5. As a result, even if the discharge destination of the paper is changed, the sheet batch printing is not interrupted. Conventionally, when the discharge destination is changed, the clearing process is performed. Even if the discharge destination is changed, the clearing process will not be performed. Therefore, the printing speed (productivity) during double-sided printing can be maintained in a high state.

  Further, when performing sheet batch printing, when a plurality of print setting information with different print resolution setting values are received, the engine control unit 4 switches the print resolution based on each print setting information and prints the sheet batch print. Part 5 continues. Accordingly, even if the print resolution is changed, the sheet batch printing is not interrupted. Conventionally, when the print resolution is changed, the settlement process is performed. Even if the print resolution is changed, the settlement process will not be performed. Therefore, the printing speed (productivity) during double-sided printing can be maintained in a high state.

  Further, when performing sheet batch printing, the engine control unit 4 causes the printing unit 5 to continue the sheet batch printing based on each print setting information even when a plurality of print setting information having different setting values of the paper type is received. .. Thus, even if the paper type is changed, the sheet batch printing is not interrupted. Conventionally, when the paper type is changed, the clearing process is performed. Even if the paper type is changed, the clearing process will not be performed. Therefore, the printing speed (productivity) during double-sided printing can be maintained in a high state.

  Further, when performing sheet batch printing, the engine control unit 4 sends sheet batch printing to the printing unit 5 based on each print setting information even when a plurality of print setting information with different set values of paper weight are received. Let it continue. As a result, even if the weight of the sheet is changed, the sheet batch printing is not interrupted. Conventionally, when there is a change in the weight of the paper, the clearing process is performed. Even if the weight of the paper is changed, the clearing process will not be performed. Therefore, the printing speed (productivity) during double-sided printing can be maintained in a high state.

  Further, the paper feeding section 5a includes a plurality of paper feeding cassettes 51. When performing sheet batch printing, when a plurality of print setting information with different setting values of the paper feeding cassette 51 used for feeding is received, the engine control unit 4 determines the paper feeding cassette used for feeding based on each print setting information. The sheet batch printing is continued in the printing unit 5 while switching 51. As a result, even if the paper feed cassette 51 used during the continuous double-sided printing is changed, the sheet batch printing is not interrupted. Conventionally, when the paper feed cassette 51 used during double-sided printing is changed, the clearing process is performed. Even if the paper feed cassette 51 used is changed, the settlement process is not performed. Therefore, the printing speed (productivity) during double-sided printing can be maintained in a high state.

  Further, the main control unit 1 controls the engine one by one with print setting information having different print settings other than the discharge destination, the print resolution, the paper type, the weight of the paper, and the set value of the paper feed cassette 51 used for paper feeding. Send to part 4. The engine control unit 4 sequentially completes printing of pages corresponding to the received print setting information. When printing of the page corresponding to the print setting information transmitted immediately before is completed, the main control unit 1 transmits the next print setting information to the engine control unit 4. As a result, the settlement process is eventually performed before the start of printing (before the paper feeding) of the page whose print setting information and the setting value of the previous page changes. Conventionally, when the settlement process should be performed, the settlement process can be performed.

  The scope of the present invention is not limited to the description of the embodiments, and various modifications may be made without departing from the spirit of the invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for a paper discharge device and an image forming apparatus including the paper discharge device.

100 printer (image forming apparatus) 1 main control unit 2 storage unit 4 engine control unit 5 printing unit 5a paper feeding unit 5c image forming unit 5e double-sided conveying unit 51 paper feeding cassette 71 upper ejection tray (destination)
72 First discharge tray (destination) 73 Second discharge tray (destination)
D1 print job data

Claims (8)

A storage unit that stores print job data including print content and print settings,
Printing including a paper feeding unit that supplies a sheet, an image forming unit that forms an image on the sheet, and a double-sided conveying unit that returns the sheet that has been single-side printed that has passed through the image forming unit to the upstream side of the image forming unit Department,
An engine control unit that controls the operation of the printing unit;
Based on the print job data, print setting information including setting values of a plurality of predetermined print setting items is transmitted to the engine control unit, and the printing unit is controlled by the engine control unit based on the print setting information. A main control unit for
Based on the print job data including pages for a plurality of sheets stored in the storage unit, when performing sheet batch printing for continuously performing double-sided printing on a plurality of sheets,
The engine control unit causes the printing unit to alternately perform continuous printing on one side and continuous printing on the other side,
The one-sided continuous printing is printing in which an image on one side of a plurality of sheets is continuously formed on the image forming unit,
The other-side continuous printing is a printing in which after the one-side continuous printing, a plurality of images on the other side of each sheet returned to the image forming section by the conveyance of the double-sided conveying section are continuously formed on the image forming section. And
The main control unit,
When the print job data for performing one double-sided printing is received , the difference in the print setting of each page for double-sided printing is recognized,
Check whether the print settings of all pages of the print job data are the same,
When the print settings of all pages are the same, one print setting information is generated, and one print setting information is transmitted to the engine control unit,
When the print settings of all pages are not the same, a plurality of print setting information is generated according to the difference of the print settings,
After transmitting the plurality of print setting information, the printing unit is caused to start the sheet batch printing,
When the plurality of print setting information are received, the engine control unit causes the printing unit to print each sheet based on the corresponding print setting information while continuing the sheet batch printing. Image forming apparatus. Having multiple discharge destinations to discharge printed matter,
When performing the sheet batch printing,
When a plurality of print setting information with different set values of the discharge destination to be discharged is received, the engine control unit switches the discharge destination to be discharged based on each of the print setting information while performing the sheet batch printing. The image forming apparatus according to claim 1, further comprising a printing unit. When performing the sheet batch printing,
When the plurality of print setting information having different print resolution setting values are received, the engine control unit causes the print unit to continue the sheet batch printing while switching the print resolution based on each of the print setting information. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. When performing the sheet batch printing,
The engine control unit causes the printing unit to continue the sheet batch printing based on each of the print setting information even when the plurality of print setting information having different setting values of the paper type are received. The image forming apparatus according to any one of items 1 to 3. When performing the sheet batch printing,
The engine control unit causes the printing unit to continue the sheet batch printing based on each of the print setting information even when the plurality of print setting information having different set values of the paper weight are received. The image forming apparatus according to claim 1, wherein the image forming apparatus comprises: The paper feed unit includes a plurality of paper feed cassettes,
When performing the sheet batch printing,
When a plurality of print setting information with different setting values of the paper feeding cassette used for paper feeding are received, the engine control unit switches the paper feeding cassette used for paper feeding based on each of the print setting information, The image forming apparatus according to claim 1, wherein the sheet batch printing is continued in the printing unit. The paper feed unit includes a plurality of paper feed cassettes,
The main control unit is configured to output the print setting information different from the print destination, the print resolution, the paper type, the weight of the paper, and the print setting other than the setting value of the paper cassette used for paper feeding, one by one to the engine. Sent to the control unit,
The engine control unit sequentially completes printing of pages corresponding to the received print setting information,
7. The main control unit transmits the next print setting information to the engine control unit when printing of a page corresponding to the print setting information transmitted immediately before is completed. The image forming apparatus according to any one of items.   Including a transport unit that transports paper,
  When printing the sheet batch,
  In the one-sided continuous printing, the engine control section causes the image forming section to continuously form images on one side for the circulating number of sheets,
  The circulating sheet number is the length of the sheet in the sheet transport direction, which is the transport distance from the image forming section through the double-sided transport section to the confluence point of the sheet provided on the upstream side of the image forming section to the transport section. 8. The image forming apparatus according to claim 1, wherein the value obtained by dividing by 1 is an integer value that is rounded down to the nearest whole number, or a value that is one less than the integer value. ..

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