JP2007052073A - Image forming apparatus, control method for image forming apparatus, program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus achieving the shortening of printing time by concurrently performing adjustment for correcting positional deviation and printing on paper, and a control method for the image forming apparatus, a program and a recording medium. <P>SOLUTION: The image forming apparatus includes two image forming parts for forming an image, and performs monochrome printing by either image forming part and adjustment for alignment between colors by the other image forming part simultaneously when a page to be printed in monochrome exists in a printing job in color printing. Since the adjustment for alignment is completed when finishing the monochrome printing, printing in a plurality of colors can be performed immediately, thereby shortening the printing time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus capable of printing on both sides simultaneously, a control method for the image forming apparatus, a program, and a recording medium, and in particular, an image forming apparatus capable of shortening the printing time, a control method for the image forming apparatus, The present invention relates to a program and a recording medium.

  In recent years, image forming apparatuses such as copiers, printers, and fax machines that can perform so-called double-sided printing that forms images on both sides of paper have become widespread. In particular, recently, image forming apparatuses capable of simultaneously printing and outputting both sides in full color have been increasing.

  As conventional techniques capable of simultaneously printing both sides, the inventions disclosed in Patent Document 1 and Patent Document 2 are known. Patent Document 1 discloses an invention relating to a printing apparatus capable of performing single-sided printing, double-sided simultaneous printing, one-step multicolor printing, one-step double-sided multicolor printing, and the like with a simple configuration.

Further, Patent Document 2 discloses an invention relating to a conversion printing machine that can reduce the number of times of ink transfer required to transfer ink from an offset plate cylinder or a collect plate cylinder onto a paper surface.
JP 2002-337438 A JP-A-2-020347

  On the other hand, in full-color printing, alignment between colors is performed. This is to correct misregistration between the colors, and paper printed without this misregistration correction will output an image that is blurred.

  However, when alignment between colors is performed, printing / output is delayed by the alignment adjustment time. On the other hand, if the alignment adjustment is not performed, the image may not be printed accurately. That is, in the conventional technology, double-sided printing and misregistration correction (alignment adjustment between colors) are performed with different operations and times, and there is no one that performs printing / output and misregistration correction at the same time.

  In view of such a problem, the present invention provides an image forming apparatus, an image forming apparatus control method, a program, and a recording medium that perform adjustment for correcting misregistration and printing on a sheet in parallel to shorten the printing time. It is intended to provide.

  In order to achieve the above object, an invention according to claim 1 is an image forming apparatus for forming an image on both sides of a transfer paper, the first image forming means for forming an image on one side of the transfer paper; A second image forming unit that forms an image on a surface opposite to the first image forming unit, and a position shift correcting unit that corrects a position shift of each color to be overlapped when transferring a plurality of colors. , A reversing unit that reverses the transfer paper after the image is formed, and when the first image forming unit performs monochromatic image formation, the second image forming unit detects the positional deviation. It is characterized by correcting.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the first image forming unit and the second image forming unit perform the transfer when the image is not formed on the transfer paper. The image forming apparatus further includes a contact / separation unit that separates from the paper, and the second image forming unit is separated from the transfer paper when the positional deviation is corrected.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, when transferring a plurality of colors, the second image forming unit after correcting the positional deviation, An image is formed on the transfer paper.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, when the monochrome image formation is on the end portion side of the print job, the print job ends. An image is formed from a partial side and output from the end part side of the print job.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, when the monochrome image formation is in the middle of the print job, the first image formation is performed. The image is formed in a single color in the middle portion by means, and the positional deviation is corrected by the second image forming means.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect, after the first image forming unit forms an image with a single color in the middle portion, the image is formed with the single color. It further has an accumulating means for accumulating the transferred transfer paper.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the fifth or sixth aspect, when the monochrome image formation is in the middle of the print job, the image formation is started from the head portion side of the print job. Then, after the print output up to the page immediately before the transfer sheet accumulated by the accumulation unit is completed, the transfer sheet is output from the accumulation unit.

  According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the fifth to seventh aspects, when the single color image formation is in the middle of the print job, the print job start portion side. Alternatively, the user can select the direction in which image formation is to be started on the end portion side.

  The invention according to claim 9 is a control method of an image forming apparatus for forming an image on both sides of a transfer paper, the first image forming step for forming an image on one side of the transfer paper, and the first A second image forming step of forming an image on a surface opposite to the image forming step, and a positional deviation correction step of correcting a positional deviation of each color to be superimposed when transferring a plurality of colors, When the monochrome image formation is performed in the first image formation step, the positional deviation is corrected in the second image formation step.

  According to a tenth aspect of the present invention, in the control method of the image forming apparatus according to the ninth aspect, when transferring a plurality of colors, the second image forming step after correcting the positional deviation. The image is formed on the transfer paper.

  According to an eleventh aspect of the present invention, in the image forming apparatus control method according to the ninth or tenth aspect, when the monochrome image formation is on the end portion side of the print job, the end portion side of the print job is displayed. And the image is output from the end portion side of the print job.

  According to a twelfth aspect of the present invention, in the control method for an image forming apparatus according to any one of the ninth to eleventh aspects, the first image is formed when monochrome image formation is in the middle of a print job. In the image forming step, a single color image in the middle portion is formed, and the positional deviation is corrected in the second image forming step.

  According to a thirteenth aspect of the present invention, in the image forming apparatus control method according to the twelfth aspect of the present invention, after the first image forming step forms an image with a single color in the middle portion, The image forming apparatus further includes an accumulation step for accumulating the transfer paper imaged in this manner.

  According to a fourteenth aspect of the present invention, in the image forming apparatus control method according to the twelfth or thirteenth aspect, when the monochrome image formation is in the middle of the print job, the image is formed from the head portion side of the print job. The transfer paper is output after the image is started and the print output up to the page immediately before the transfer paper accumulated in the accumulation step is completed.

  According to a fifteenth aspect of the present invention, in the control method for an image forming apparatus according to any one of the twelfth to fourteenth aspects, when the monochrome image formation is in the middle of the print job, the print job It is characterized in that the user can select the direction in which image formation is to be started from the head portion side or the end portion side.

  According to a sixteenth aspect of the present invention, there is provided a program for an image forming apparatus for forming an image on both sides of a transfer sheet, wherein the first image forming process for forming an image on one side of the transfer sheet is performed on a computer. A second image forming process that forms an image on the opposite side of the one image forming process, a misregistration correction process that corrects a misregistration of each color to be superimposed when transferring multiple colors, and an image forming process. And performing reversal processing for reversing the transferred transfer paper, and performing the monochrome image formation by the first image formation processing, the position deviation is corrected by the second image formation processing. And

  According to a seventeenth aspect of the present invention, in the program of the image forming apparatus according to the sixteenth aspect, when transferring a plurality of colors, in the second image forming process after correcting the positional deviation, An image is formed on the transfer paper.

  According to an eighteenth aspect of the present invention, in the image forming apparatus program according to the sixteenth or seventeenth aspect, when the monochrome image formation is on the end portion side of the print job, the end portion side of the print job is started. An image is formed and output from the end portion side of the print job.

  According to a nineteenth aspect of the present invention, in the image forming apparatus program according to any one of the sixteenth to eighteenth aspects, the first color image is formed when a monochrome image is formed in the middle of a print job. In the image forming process, a single color image in the middle portion is formed, and the positional deviation is corrected in the second image forming process.

  According to a twentieth aspect of the invention, in the program of the image forming apparatus according to the nineteenth aspect, after the first image forming process performs image formation with a single color in the middle portion, the single color image is generated. An accumulation process for accumulating the imaged transfer paper is further performed.

  According to a twenty-first aspect of the present invention, in the image forming apparatus program according to the nineteenth or twentieth aspect, when the monochrome image formation is in the middle of the print job, the image formation is performed from the head portion side of the print job. Is started, and after the print output up to the page immediately before the transfer sheet accumulated by the accumulation process is completed, the transfer sheet is output.

  According to a twenty-second aspect of the present invention, in the program of the image forming apparatus according to any one of the nineteenth to twenty-first aspects, if the monochrome image formation is in the middle of the print job, the start of the print job It is characterized in that the user can select the direction in which image formation is to be started from the partial side or the end partial side.

  A twenty-third aspect of the invention is a computer-readable recording medium on which the program according to the sixteenth to twenty-second aspects is recorded.

  As described above, according to the image forming apparatus, the control method of the image forming apparatus, the program, and the recording medium of the present invention, the adjustment for correcting the misregistration and the printing on the paper are performed in parallel, so the printing time is shortened. be able to.

[First Embodiment]
Hereinafter, the image forming apparatus of the present embodiment will be described with reference to the drawings. In addition, this embodiment is not limited to what is described below, A various change is possible in the range which does not deviate from the meaning. The image forming apparatus according to the present embodiment will be described using a multifunction peripheral. Further, the image forming means of this multifunction device will be described as adopting an intermediate transfer system.

FIG. 1 is a block diagram illustrating a configuration of a multifunction machine according to the present embodiment.
As shown in FIG. 1, the multifunction peripheral of the present embodiment includes an image forming unit 100, an image reading unit 200, and a paper feeding unit 300.

  When a document is set on the document conveying device of the image reading unit 200 or on the contact glass and the operation of the multifunction device of the present embodiment is started, the light source, the plurality of mirrors, and the imaging optical lens of the image reading unit 200 are started. A document image is read using an image sensor such as a CCD. The image data read here is sent to the image forming unit 100.

  When the transfer paper S is conveyed from the paper feed tray 7 or the manual feed tray 8 via the transfer paper conveyance path 2, the transfer paper is transferred by the image forming unit 1 of the image forming unit 100 based on the read image data. S is imaged. The transfer sheet S is conveyed to the paper discharge unit 4 after the image is fixed by the fixing unit 3. Here, when printing is also performed on the opposite surface of the imaged transfer paper S, the paper is discharged from the paper discharge unit 4 to the reversing mechanism 5. On the other hand, when printing is completed, the paper is discharged from the paper discharge unit 4 to the paper discharge tray 6.

  The transfer sheet S conveyed (discharged) to the reversing mechanism 4 is reversed here, so that the front surface and the back surface of the transfer sheet S are reversed, and again to the image forming unit 1 via the transfer sheet conveyance path 2. Be transported. In this case, the transfer sheet S formed on the back surface by the image forming unit 1 is discharged to the discharge tray 6 via the fixing unit 3 and the discharge unit 4.

  Further, as will be described in detail in the third embodiment, when there is monochrome printing in the middle of a print job, the monochrome printing page after monochrome printing is temporarily stored in the staple tray 9. Then, after printing a plurality of color pages, when the printing is completed until just before the single color print page, the single color print page is discharged from the staple tray 9 via the paper discharge unit 4.

Next, the characteristic part of the multifunction peripheral of this embodiment will be described in more detail.
FIG. 2 is an enlarged view of the configuration of the image forming unit 1 in the multifunction peripheral according to the present embodiment.

  The image forming unit 1 in the multifunction peripheral according to the present embodiment includes a first image forming unit and a second image forming unit. As shown in FIG. 2, in the image forming unit 1 of the present embodiment, the first image forming unit and the second image forming unit are symmetrical when viewed from between the transfer paper carry-out path transfer inlet and the transfer paper carry-out path transfer outlet. It is arranged to be.

  The first image forming unit includes photosensitive drums 11Y, 11M, 11C, and 11K on the first image forming unit side corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K). A contact / separation mechanism 12, an alignment sensor 13, an intermediate transfer belt 14, and a transfer belt 15.

  Images latently formed on the photosensitive drums 11Y, 11M, 11C, and 11K are transferred onto the intermediate transfer belt 14. The transferred image is further transferred onto the transfer belt 15 and transferred / imaged onto the transfer paper S carried in from the transfer paper carry-out path transfer entrance.

  The intermediate transfer belt 14 and the transfer belt 15 can be brought into contact with and separated from the nip by the contact / separation mechanism 12, and can switch whether the intermediate transferred image is transferred to the transfer sheet S or not.

  In the correction of the misalignment, an image for alignment adjustment by the photosensitive drums 11Y, 11M, 11C, and 11K is transferred onto the intermediate transfer belt. With respect to this transferred image, the positional deviation amount is detected by the alignment sensor 13 to correct the positional deviation. At this time, the intermediate transfer belt 14 and the transfer belt 15 are separated by the contact / separation mechanism 12 so that the image for alignment adjustment is not transferred to the transfer paper S. Further, since the single color printing with the color of any one of the photosensitive drums 11Y, 11M, 11C, and 11K does not require color superposition, the alignment adjustment is not necessary.

  The configuration of the second image forming unit is basically the same as that of the first image forming unit, corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K). The photosensitive drums 16Y, 16M, 16C, and 16K on the second image forming unit side, the contact / separation mechanism 17, the alignment sensor 18, the intermediate transfer belt 19, and the transfer belt 20 are included.

  The latent images on the photosensitive drums 16Y, 16M, 16C, and 16K are transferred onto the intermediate transfer belt 19. The transferred image is further transferred onto the transfer belt 20, and transferred and imaged onto the transfer paper S carried in from the transfer paper carry-out path transfer entrance.

  The intermediate transfer belt 19 and the transfer belt 20 can be brought into contact with and separated from the nip by the contact / separation mechanism 17, and can switch whether the intermediate transferred image is transferred to the transfer sheet S or not.

  In the correction of the positional deviation, an image for alignment adjustment by each of the photosensitive drums 16Y, 16M, 16C, and 16K is transferred onto the intermediate transfer belt 19. With respect to this transferred image, the positional deviation amount is detected by the alignment sensor 18 to correct the positional deviation. At this time, the intermediate transfer belt 19 and the transfer belt 20 are separated by the contact / separation mechanism 17 so that the image for alignment adjustment is not transferred onto the transfer paper S.

  By interlocking the first image forming unit and the second image forming unit, one image forming unit performs monochromatic printing, and the other image forming unit performs inter-color alignment adjustment in preparation for multi-color printing. become.

  FIG. 3 is a block diagram showing a software configuration in the image forming apparatus of the present embodiment.

  The image forming apparatus according to the present embodiment includes an application layer 21, a system management unit 22, a scanner unit 23, an image management unit 24, an operation unit 25, a plotter unit 26, and a communication unit 27. The scanner unit 23 is connected to a document feeder (DF: document feeder) 28, the image processing unit 24 is connected to an image memory 29 and an HDD 30, and the plotter unit 26 is connected to a finisher 31.

  The application layer 21 is various application layers used in the image forming apparatus of the present embodiment, and activates an application based on a request from the system management unit 22 that manages overall system control. The scanner unit 23 reads a document conveyed from the DF 28 and converts it into image data. The image management unit 24 stores the document image conveyed from the DF 28 and read by the scanner unit 23 in the image memory 29 or the HDD 30 and reads the stored image data.

  The user operates the image forming apparatus using the operation unit 25. The plotter unit 26 forms a document image on a sheet, and after the image is formed on the sheet, the sheet is output from the finisher unit 31. The communication unit 27 mediates communication between the image forming apparatus and the outside, and is connected to the network via the communication unit 27.

Next, the operation of the image forming apparatus of this embodiment will be described with reference to the drawings.
FIG. 4 is a flowchart showing an operation when there is monochrome printing at the head of a print job in the image forming apparatus of the present embodiment.

  When printing is started, first, it is confirmed whether or not there is a single color page print at the beginning of the print job (step S101). Here, when there is monochrome page printing (step S101 / YES), in order from the first page in the print job, one of the first and second image forming units is used for the back surface. Printing in a single color is executed by image formation (step S102). Simultaneously with this monochromatic printing, on the opposite surface, the other image forming unit different from the image forming unit selected in step S102 is used to adjust the alignment between the colors in the surface image formation ( Step S103).

  Next, it is confirmed whether or not the alignment adjustment has been completed (step S104). When the alignment adjustment has been completed (step S104 / YES), printing of the remaining pages, that is, a plurality of colors, is executed from the first page in front image formation (step S105), and printing is performed. Continue or end.

  On the other hand, when the alignment adjustment is not completed (step S104 / No), it is confirmed whether or not the monochrome page is continued (step S106). If the single color page is continued (step S106 / YES), the process returns to step S102, and the next single color page is printed by image formation for the back side.

  When the monochrome page is finished (step S106 / No), it is confirmed again whether or not the alignment adjustment is finished (step S107). When the alignment adjustment is completed (step S107 / YES), the process proceeds to step S105 for printing the remaining pages. If the alignment adjustment has not been completed (step S107 / No), a check is performed, for example, at regular time intervals until the alignment adjustment is completed.

  If there is no single-color page printing at the beginning of the print job (step S101 / No), the process proceeds to step S107 where the alignment adjustment is completed until the adjustment is completed.

  As described above, according to the multifunction peripheral of this embodiment, when there is a single-color print page at the top of a print job, printing can be started earlier than conventional printing. Therefore, the total printing time can be shortened.

[Second Embodiment]
Further, according to the multifunction machine of the present embodiment, it is possible to perform printing quickly even when there is monochrome printing at the end of the print job.
FIG. 5 is a flowchart illustrating an operation when there is monochrome printing at the end of a print job in the multifunction peripheral according to the present embodiment.

  When printing is started, first, it is confirmed whether or not there is a single-color page printing at the beginning of the print job (step S201). If there is monochrome page printing (step S201 / YES), the process proceeds to a printing step (described in FIG. 4 described above) when there is a monochrome print page at the top of the print job.

  If there is no single-color page printing at the beginning of the print job (step S201 / No), it is then checked whether there is a single-color page print at the end (rear end) of the print job (step S202). ). If there is single-color printing at the rear end of the print job (step S202 / YES), one of the first and second image forming units starts from the rear end page in order for the back side. In step S203, single color printing is executed. At this time, the printed page that is finally output is output so as to be a so-called face-up surface.

  Simultaneously with this monochromatic printing, on the opposite surface, the other image forming unit different from the image forming unit selected in step S203 is used to adjust the alignment between the colors in the surface image formation ( Step S204).

  Next, it is confirmed whether or not the alignment adjustment has been completed (step S205). When the alignment adjustment has been completed (step S205 / YES), the remaining pages, that is, printing in a plurality of colors, is executed from the first page of the print job by image formation for the front side (step S206). ) Continue / end printing.

  In this case as well, after the page printing in a plurality of colors is completed, the printed page that is finally output is output so that the surface is the top, that is, so-called face-up.

  On the other hand, when the alignment adjustment is not completed (step S205 / No), it is confirmed whether or not the monochrome page is continued (step S207). If the single color page is continued (step S207 / YES), the process returns to step S203, and the next single color page is printed by image formation for the back side.

  When the monochrome page is finished (step S207 / No), it is confirmed again whether or not the alignment adjustment is finished (step S208). When the alignment adjustment is completed (step S208 / YES), the process proceeds to step S206 for printing the remaining pages. If the alignment adjustment has not been completed (step S208 / No), a check is performed, for example, at regular time intervals until the alignment adjustment is completed.

  If there is no single-color page printing at the rear end of the print job (step S202 / No), the process proceeds to step S208 in which the alignment adjustment is performed until the adjustment is completed.

  As described above, according to the MFP of the present embodiment, even when there is a print page in a single color at the rear end portion of the print job, the single color printing is started from the rear end portion and the alignment adjustment is performed at the same time. Can do. Therefore, it is possible to shorten the printing time compared to conventional printing.

[Third Embodiment]
Furthermore, according to the multifunction machine of the present embodiment, if there is a single-color page printing in the middle of a print job, it is possible to print faster than before.
FIG. 6 is a flowchart illustrating an operation when there is single color printing in the middle of a print job in the multifunction peripheral according to the present embodiment.

  When printing is started, first, it is confirmed whether or not there is single-color page printing at the beginning or the rear end of the print job (step S301). If there is no single-color page printing at the beginning or the rear end of the print job (step S301 / No), it is next checked whether there is a single-color page print in the middle of the print job. (Step S302).

  If there is single color printing in the middle of the print job (step S302 / YES), one of the first image forming unit and the second image forming unit is used for the back side in order from the single color print page. In step S303, single color printing is executed. At this time, the single-color print page printed prior to the multiple-color print page is temporarily stored in the staple tray in the image forming apparatus.

  Simultaneously with this monochromatic printing, on the opposite surface, the other image forming unit, which is different from the image forming unit selected in step S303, is used to adjust the alignment between the colors in the surface image formation ( Step S304).

  Next, it is confirmed whether or not the alignment adjustment has been completed (step S305). If the alignment adjustment has been completed (step S305 / YES), the remaining pages, that is, printing in a plurality of colors is executed from the first page of the print job (step S306).

  Thereafter, it is confirmed whether or not the print job has been completed before the single color print page that has been printed prior to the multi-color print page (step S307). When printing has been completed up to the preceding single-color page (step S307 / Yes), the single-color print page once stored in the staple tray is replaced with the multi-color print page, that is, the original single-color page. Is discharged to the corresponding location where the print page is located (step S308). At this time, stapling is not performed on the single-color print page to be released.

  In this way, after the print pages of a plurality of colors and the print pages of a single color are printed in order, the remaining pages of the print job are printed with image formation for the front side (step S309).

  On the other hand, if the multi-color print page has not been printed up to the previous single-color page (step S307 / No), printing is continued until the front of the single-color print page by image formation for the surface. To continue.

  If the alignment adjustment has not been completed (step S305 / No), it is confirmed whether or not the monochrome page continues (step S310). If the monochrome page continues (step S310 / YES), the process returns to step S303, and the next monochrome page is printed with the back side image formation.

  If the monochrome page is finished (step S310 / No), it is checked again whether or not the alignment adjustment is finished (step S311). When the alignment adjustment is completed (step S311 / YES), the process proceeds to step S306, where printing of a plurality of colors is performed from the first page of the print job by image formation for the front side. If the alignment adjustment has not been completed (step S311 / No), for example, a check is performed at regular time intervals until the alignment adjustment is completed.

  If there is no single-color page printing in the middle of the print job (step S302 / No), the process proceeds to step S311 where the alignment adjustment is completed until the adjustment is completed.

  Further, if there is a single color page print at the beginning or the rear end of the print job (step S301 / YES), it is confirmed whether there is a single color page print at the top of the print job (step S312). Here, when there is monochrome printing at the beginning of the print job (step S312 / YES), the printing step when there is a monochrome print page at the beginning of the print job (explained in FIG. 4 described above). Transition. On the other hand, if there is monochrome printing at the trailing end of the print job (step S312 / No), the process proceeds to a printing step (described in FIG. 5 described above) when there is a monochrome print page at the end of the print job. Transition.

  As described above, according to the image forming apparatus of the present embodiment, even when there is no single-color page printing at the beginning or rear end of the print job, there is a single-color page printing in the middle of the print job. For example, a single color page is printed in advance, temporarily stored in the staple tray after printing, and the single color page is released from the staple tray when the single color page is located after printing the multiple color pages. Therefore, if there is a single color page printing in the middle of a print job, printing / output can be performed earlier than the conventional printing time.

  Needless to say, the operation of the image forming apparatus according to the present embodiment may be implemented as a program in another image forming apparatus, or may be recorded on a computer-readable recording medium such as a CD-ROM. Yes.

  In this embodiment, in the case where there is a single-color page in the middle of a print job, it is assumed that after the single-color print page is printed and stored in the staple tray, the front image is formed from the top of the print job. did. However, in the image forming apparatus according to the present embodiment, it is also possible to perform printing / output from a page on the rear end side, not from the top page.

  In this case, whichever side of the print job starts from the first side or the rear end side, the one that has fewer pages to the monochrome print page, as viewed from the first side or the rear end side of the print job. Will automatically start printing. That is, for example, when the number of pages from the end (last end) page to the monochrome print page is smaller than the number of pages from the first page to the monochrome print page, printing is started from the rear end side.

  In addition, the user may designate the print start side of the first side and the rear end side of the print job. For example, if only the function of automatically selecting the one with a smaller number of pages up to a single color page is used, even if the user wants to output from the first page, it is output from the rear end page. This is because there is a risk of losing.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment. FIG. 3 is a diagram illustrating an example of an image forming unit in the image forming apparatus of the present embodiment. 3 is a block diagram illustrating a software configuration of the image forming apparatus according to the present exemplary embodiment. FIG. 3 is a flowchart illustrating an operation in the image forming apparatus of the first embodiment. 10 is a flowchart illustrating an operation in the image forming apparatus according to the second embodiment. 10 is a flowchart illustrating an operation in the image forming apparatus of the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming part 2 Transfer paper conveyance path 3 Fixing unit 4 Paper discharge unit 5 Reverse mechanism 6 Paper discharge tray 7 Paper feed tray 8 Manual feed tray 11Y, 11M, 11C, 11K, 16Y, 16M, 16C, 16K Photosensitive drum 12, 17 Contact / Separation Mechanism 13, 18 Positioning Sensor 14, 19 Intermediate Transfer Belt 15, 20 Transfer Belt 21 Application Layer 22 System Management Unit 23 Scanner Unit 24 Image Management Unit 25 Operation Unit 26 Plotter Unit 27 Communication Unit 28 Document Feeder (DF) : Document feeder)
29 Image memory 30 HDD
31 Finisher 100 Image forming unit 200 Image reading unit 300 Paper feeding unit

Claims (23)

An image forming apparatus for forming an image on both sides of a transfer paper,
First image forming means for forming an image on one surface of the transfer paper;
Second image forming means for forming an image on a surface opposite to the first image forming means;
A misregistration correction means for correcting misregistration of each color to be overlaid when transferring a plurality of colors;
Reversing means for reversing the transfer paper after image formation,
An image forming apparatus, wherein when the first image forming unit performs monochromatic image formation, the second image forming unit corrects the positional deviation. The first image forming means and the second image forming means further have contact / separation means for separating from the transfer paper when image formation is not performed on the transfer paper,
The image forming apparatus according to claim 1, wherein when the misregistration is corrected, the second image forming unit is separated from the transfer sheet. When transferring multiple colors,
3. The image forming apparatus according to claim 1, wherein the second image forming unit that corrects the positional deviation forms an image on the transfer paper. 4. If the monochrome image is on the end of the print job,
4. The image forming apparatus according to claim 1, wherein an image is formed from an end portion side of the print job and output from the end portion side of the print job. 5. If monochrome image creation is in the middle of a print job,
5. The image forming apparatus according to claim 1, wherein the first image forming unit performs image formation with a single color in the middle portion, and the second image forming unit corrects the positional deviation. 2. The image forming apparatus according to item 1.   6. The image forming apparatus according to claim 5, further comprising an accumulating unit that accumulates the transfer sheet imaged in the single color after the first image forming unit forms an image in the single color in the middle portion. The image forming apparatus described in 1. If monochrome image creation is in the middle of a print job,
The image forming is started from the head portion side of the print job, and after the print output up to the page immediately before the transfer sheet accumulated by the accumulation unit is completed, the transfer sheet is output from the accumulation unit. The image forming apparatus according to claim 5 or 6. If monochrome image creation is in the middle of a print job,
8. The image forming apparatus according to claim 5, wherein the user can select a direction in which image formation is started from a head part side or an end part side of the print job. 9. A method for controlling an image forming apparatus that forms images on both sides of a transfer paper,
A first image forming step of forming an image on one side of the transfer paper;
A second image forming step of forming an image on a surface opposite to the first image forming step;
A misregistration correction step for correcting misregistration of each color to be overlaid when transferring a plurality of colors;
A method for controlling an image forming apparatus, comprising: correcting the positional deviation in the second image forming step when performing monochrome image formation in the first image forming step. When transferring multiple colors,
The method of controlling an image forming apparatus according to claim 9, wherein an image is formed on the transfer paper in the second image forming step after correcting the positional deviation. If the monochrome image is on the end of the print job,
11. The method of controlling an image forming apparatus according to claim 9, wherein image formation is performed from the end portion side of the print job and output from the end portion side of the print job. If monochrome image creation is in the middle of a print job,
12. The image forming apparatus according to claim 9, wherein the first image forming step forms an image with a single color in the middle portion, and the second image forming step corrects the displacement. 2. A method for controlling an image forming apparatus according to item 1.   13. The image forming apparatus according to claim 12, further comprising an accumulation step of accumulating transfer paper imaged in the single color after image formation with the single color in the middle portion in the first image forming step. A method for controlling the image forming apparatus according to the above. If monochrome image creation is in the middle of a print job,
The image forming is started from the head portion side of the print job, and the transfer sheet is output after the print output to the page immediately before the transfer sheet accumulated in the accumulation step is completed. 14. A method for controlling an image forming apparatus according to 12 or 13. If monochrome image creation is in the middle of a print job,
15. The method of controlling an image forming apparatus according to claim 12, wherein a user can select a direction in which image formation is started from a head part side or an end part side of a print job. . A program for an image forming apparatus that forms images on both sides of a transfer paper,
On the computer,
A first image forming process for forming an image on one side of the transfer paper;
A second image forming process for forming an image on a surface opposite to the first image forming process;
A positional deviation correction process for correcting the positional deviation of each color to be overlaid when transferring multiple colors;
Execute the reversal process to reverse the transfer paper after the image is formed,
A program for an image forming apparatus, wherein when the first image forming process is performed in a single color, the positional deviation is corrected by the second image forming process. When transferring multiple colors,
The program of the image forming apparatus according to claim 16, wherein the image is formed on the transfer paper in the second image forming process after correcting the misregistration. If the monochrome image is on the end of the print job,
18. The program of the image forming apparatus according to claim 16, wherein the image forming apparatus forms an image from the end portion side of the print job and outputs the image from the end portion side of the print job. If monochrome image creation is in the middle of a print job,
19. The image forming apparatus according to claim 16, wherein the first image forming process forms an image with a single color in the middle portion, and the second image forming process corrects the positional deviation. 2. A program for an image forming apparatus according to item 1.   2. The image forming apparatus according to claim 1, wherein after the first image forming process is performed with a single color in the middle of the first image forming process, an accumulation process for accumulating the transfer paper image formed with the single color is further performed. 19. A program for an image forming apparatus according to 19. If monochrome image creation is in the middle of a print job,
The image forming is started from the head portion side of the print job, and the transfer sheet is output after the print output to the page immediately before the transfer sheet accumulated by the accumulation process is completed. The program of the image forming apparatus as described in 19 or 20. If monochrome image creation is in the middle of a print job,
The program of the image forming apparatus according to any one of claims 19 to 21, wherein a user can select a direction in which image formation is started from a head part side or an end part side of a print job.   A computer-readable recording medium on which the program according to claim 16 is recorded.

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