JP2013240915A - Printer and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the reduction of a speed of forming an image as a whole while reducing a margin between pages.SOLUTION: A printer includes: a conveying part which carries out the conveying operation of conveying a medium in a conveying direction; a sensor which detects a position of a reference mark of the medium in the conveying direction; a nozzle array which has a plurality of nozzles for jetting ink on the medium arranged in a direction along the conveying direction and carries out the jetting operation of jetting the ink on the medium by moving in an intersecting direction intersecting the conveying direction; and a control part which controls the jetting operation and the conveying operation. The control part corrects a transition conveyance amount of the conveying operation between the last jetting operation for forming an image on a first page and the first jetting operation on a second page as the next page to the first page out of conveyance amounts of the medium in the conveying operation based on a detection position of the reference mark. The transition conveyance amount is smaller than an interval between a nozzle on an uppermost stream side and a nozzle on a most downstream side in the conveying direction in the nozzle array.

Description

  The present invention relates to a printing apparatus and a printing method.

  An ink jet printing apparatus that forms an image by ejecting ink onto a medium has been developed. In such an ink jet type printing apparatus, for example, a seal can be used as a printing medium. In the case of a seal print medium, the seal may be stamped into a label shape on which an image is formed. When such a die-cut printing medium is continuously fed from a roll body, an image may not be appropriately formed on the die-cut label unless the printing position is adjusted with high accuracy. For example, there arises a problem that the image protrudes from the label shape. For this reason, in order to maintain the printing position appropriately, a reference mark for defining the reference position may be provided on the print medium.

JP 2006-272769 A

  When the fiducial mark is used, the printing position is corrected for each page, so printing is performed in units of pages. When printing is performed in units of pages, the top edge processing and the bottom edge processing are performed on each page, which causes a problem that throughput is lowered. On the other hand, when lower end processing is replaced with normal printing processing in order to avoid a decrease in throughput, there is a problem that backfeeding of the medium is necessary or a margin between pages corresponding to the reference mark is increased. . That is, it is desirable to suppress a decrease in the speed of the entire image formation while reducing the margin between pages.

  The present invention has been made in view of such circumstances, and an object thereof is to suppress a decrease in the speed of the entire image formation while reducing a margin between pages.

The main invention for achieving the above object is:
A transport unit that performs a transport operation of transporting the medium in the transport direction;
A sensor for detecting a position of a reference mark in the conveyance direction of the medium;
A nozzle row having a plurality of nozzles for ejecting ink onto the medium in a direction along the transport direction, the nozzle row performing an ejection operation of ejecting ink onto the medium by moving in an intersecting direction intersecting the transport direction; ,
A controller that controls the ejection operation and the transport operation;
The control unit includes a final ejection operation for forming an image of the first page, and a first ejection operation for a second page, which is the next page of the first page, out of the transport amount of the medium in the transport operation. And correcting the transition transport amount of the transport operation between and based on the detection position of the reference mark,
The transition conveyance amount may be a printing apparatus that is shorter than an interval between the most upstream nozzle and the most downstream nozzle in the conveyance direction in the nozzle row.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

1 is a block diagram of a printing system 100 in the present embodiment. 1 is a perspective view of an inkjet printer 1 in the present embodiment. It is an internal side view of the inkjet printer 1 in this embodiment. 4 is an explanatory diagram of relative positions of a head 41, a reference mark mrk, and a detection sensor 31 in the printer 1. It is explanatory drawing of the nozzle structure in the head in this embodiment. 6A and 6B are explanatory diagrams of normal printing. It is explanatory drawing of front end printing and rear end printing. It is explanatory drawing of the medium Md used by this embodiment. It is explanatory drawing of the relative position with respect to the medium of the head in a reference example. It is explanatory drawing of the printing process of the reference example in the case of performing a front end printing process and a rear end printing process. It is explanatory drawing of the printing process of a reference example. It is explanatory drawing of the printing process of the reference example in the case of carrying out back feed. It is explanatory drawing of the printing process in this embodiment. It is explanatory drawing of the relative position with respect to the medium of the head in this embodiment. It is explanatory drawing of the relative position with respect to the medium of a head in the case of performing a rear end process in this embodiment.

At least the following matters will become clear from the description of the present specification and the accompanying drawings. That is,
A transport unit that performs a transport operation of transporting the medium in the transport direction;
A sensor for detecting a position of a reference mark in the conveyance direction of the medium;
A nozzle row having a plurality of nozzles for ejecting ink onto the medium in a direction along the transport direction, the nozzle row performing an ejection operation of ejecting ink onto the medium by moving in an intersecting direction intersecting the transport direction; ,
A controller that controls the ejection operation and the transport operation;
The control unit includes a final ejection operation for forming an image of the first page, and a first ejection operation for a second page, which is the next page of the first page, out of the transport amount of the medium in the transport operation. And correcting the transition transport amount of the transport operation between and based on the detection position of the reference mark,
The transition conveyance amount may be a printing apparatus that is shorter than an interval between the most upstream nozzle and the most downstream nozzle in the conveyance direction in the nozzle row.

  As described above, since the transition conveyance amount between the last ejection operation of the first page and the first ejection of the second page is short, a margin between pages can be reduced. In addition, a transport error may occur when the medium is transported in the transport direction, but the transport error can be corrected based on the detection position of the reference mark. At this time, since only the transition conveyance amount is corrected, a decrease in the image forming speed can be suppressed. That is, it is possible to suppress a decrease in the speed of the entire image formation while reducing the margin between pages.

In this printing apparatus, the image of the first page is formed on the downstream side of the reference mark in the transport direction, and the image of the second page is formed on the upstream side of the reference mark. desirable.
By doing so, the print start position of the image of the second page can be appropriately corrected by detecting the position of the reference mark.

Further, it is preferable that the image of the first page and the image of the second page do not overlap with the reference mark in the transport direction.
By doing so, it is possible to prevent ink from being ejected onto the raster line of the reference mark.

In addition, it is preferable that the first page image and the second page image overlap the reference mark in the intersecting direction.
By doing so, since the reference mark is located at a position close to the image of the second page, the print start position of the image of the second page can be corrected with high accuracy.

In addition, it is preferable that the transport amount in the transport operation between the last spray operation and the spray operation immediately before the last spray operation is larger than the nozzle pitch in the nozzle row.
In this way, even in the case of printing the so-called normal area in the formation of the image of the final portion of the first page, since the transition conveyance amount is short, the speed of the entire image formation while reducing the margin between pages. The decrease can be suppressed.

Further, the transport amount in the transport operation between the last spray operation and the spray operation immediately before the last spray operation may be less than the nozzle pitch in the nozzle row.
In this way, even when so-called trailing edge printing is performed in the formation of the image of the final portion of the first page, since the transition conveyance amount is short, the overall speed of image formation is reduced while reducing the margin between pages. Can be suppressed.

Moreover, it is preferable that the conveyance amount in the conveyance operation between the first injection operation and the injection operation immediately after the first injection operation is less than the nozzle pitch in the nozzle row.
In this way, even when so-called leading edge printing is performed in the formation of the image of the first portion of the second page, since the transition conveyance amount is short, the overall speed of image formation is reduced while reducing the margin between pages. Can be suppressed.

In addition, at least the following matters will become clear from the description of the present specification and the accompanying drawings. That is,
Detecting a position of the reference mark in the conveyance direction of the medium;
Moving the nozzle row in the intersecting direction intersecting the transport direction to eject ink, and performing a final ejecting operation to form an image of the first page;
Performing a transport operation for transporting the medium in the transport direction by a transition transport amount;
Moving the nozzle row in the intersecting direction to eject ink and performing a first ejection operation to form an image of a second page that is the next page of the first page;
Including
The transition carry amount is corrected based on the detection position of the reference mark,
In the printing method, the transition conveyance amount is shorter than an interval between the most upstream nozzle and the most downstream nozzle of the conveyance amount in the nozzle row.
As described above, since the transition conveyance amount between the last ejection operation of the first page and the first ejection of the second page is short, a margin between pages can be reduced. In addition, a transport error may occur when the medium is transported in the transport direction, but the transport error can be corrected based on the detection position of the reference mark. At this time, since only the transition conveyance amount is corrected, a decrease in the image forming speed can be suppressed. That is, it is possible to suppress a decrease in the speed of the entire image formation while reducing the margin between pages.

=== Embodiment ===
FIG. 1 is a block diagram of a printing system 100 in the present embodiment. Hereinafter, a schematic configuration of the printing system 100 in the present embodiment will be described with reference to these.

  The printing system 100 includes an inkjet printer 1 (hereinafter simply referred to as “printer 1”) as a printing device, a computer 110, a display device 120, and an input device 130. The printer 1 prints an image on a medium such as paper, cloth, or film. The computer 110 is communicably connected to the printer 1 via the interface 112. In order to cause the printer 1 to print an image, the computer 110 outputs print data including image data corresponding to the image to the printer 1. The computer 110 includes a CPU 113, a memory 114, an interface 112, and a recording / reproducing device 140. Computer programs such as application programs and printer drivers are installed. The recording / reproducing device 140 is, for example, a flexible disk drive device or a CD-ROM drive device.

  The display device 120 is, for example, a liquid crystal monitor. The display device 120 is for displaying a user interface of a computer program, for example. The input device 130 is, for example, a keyboard or a mouse.

  The ink jet printer 1 includes a paper transport unit 20, a recording unit 40, a controller 51, and a drive signal generation unit 52.

  The paper transport unit 20 includes a transport roller 22 and a paper discharge roller 24. The transport roller 22 supplies the medium from the roll R to the recording unit 40. The paper discharge roller 22 discharges the printed medium. The rotation amount of the transport roller 22 is controlled by the controller 51. Therefore, the controller 51 always knows the medium conveyance amount based on the controlled rotation amount.

  As will be described later, the recording unit 40 moves the carriage 43 on which the head 41 is mounted, and ejects ink from the head 41 to form an image on the medium.

  In addition, the inkjet printer 1 includes a controller 51 that comprehensively controls the operation of each component device. The controller 51 includes a CPU 51a that performs calculations, a memory 51b that stores programs and calculation results, and an interface 51c that communicates with external devices. The controller 51 controls the paper transport unit 20, the recording unit 40, and the drive signal generation unit 52.

  The drive signal generation unit 52 supplies a drive signal COM to each piezo element (not shown) of the head 41 of the recording unit 40. The drive signal generation unit 52 receives digital data defining the shape of the drive signal from the controller 51, and generates a drive signal COM that is a voltage waveform based on the digital data.

  FIG. 2 is a perspective view of the ink jet printer 1 according to the present embodiment. FIG. 3 is an internal side view of the inkjet printer 1 in the present embodiment. In the following description, the conveyance direction (discharge direction) of the medium is the X-axis direction, the width direction (perpendicular to the paper surface in FIG. 3) of the conveyance path 26 orthogonal to the X-axis direction is the Y-axis direction, the X-axis direction, and the Y-axis. A vertical direction orthogonal to the axial direction may be referred to as the Z-axis direction in some cases.

  As shown in FIG. 2, the inkjet printer 1 includes a recording unit 40 that is horizontally arranged in the longitudinal direction, a casing 90 that is attached to the end of the recording unit 40, and an upper side of the recording unit 40. The loading unit 10 includes a leg unit 70 that supports the recording unit 40 and the housing 90 from below.

  Further, the printer 1 is provided with a detection sensor 31 for detecting a reference mark mrk of a medium to be described later. The detection sensor 31 is, for example, an optical detection sensor. The detection sensor 31 is provided on the upstream side of the head 41 in the transport direction. Further, the controller 51 grasps the transport amount of the medium based on the rotation amount of the transport roller 22. Therefore, it is also known how much the detection sensor 31 has been conveyed since the medium reference mark mrk was detected.

  The recording unit 40 includes a head 41 that ejects ink onto a medium conveyed along the conveyance path 26. The head 41 is mounted on a carriage 43 that is movable in the width direction of the transport path 26. An ink cartridge (not shown) that stores ink is mounted on the carriage 43. The head 41 includes a plurality of nozzle rows and is configured to eject each ink. The head 41 performs image formation for recording information such as a predetermined image and characters by ejecting ink onto the recording surface of the medium.

  The medium on which the image is formed by the recording unit 40 is discharged from the discharge roller 24. The discharge roller 24 includes a mechanism that switches a roller that nips depending on the paper type to a serrated roller 25a or a roller roller 25b.

  A winding mechanism (not shown) is provided on the downstream side of the discharge roller 24. The winding mechanism has a function of winding a printed medium in a roll shape.

  An operation panel 80 is disposed on the upper surface of the housing 90. The operation panel 80 includes a plurality of switches 82 operated by the user, and a display unit 84 that indicates an operation state of the printer 1. Accordingly, the user operates the printer 1 from the front side with the side on which the operation panel 80 and the cartridge holder are disposed as the front side.

  FIG. 4 is an explanatory diagram of the relative positions of the head 41, the reference mark mrk, and the detection sensor 31 in the printer 1. FIG. 4 shows each element inside the printer 1 and the medium Md conveyed inside the printer 1.

  For example, FIG. 4 shows the head 41, the detection sensor 31, and the transport roller 22. The medium Md is provided with a reference mark mrk. The reference mark mrk may be any mark that can be detected optically. Here, the reference mark mrk is formed by hollowing out a part of the medium md. In order to detect such a reference mark mrk, the detection sensor 31 is provided at a position overlapping the reference mark mrk in the head moving direction.

  The controller 51 of the printer 1 counts the rotation amount of the transport roller 22 and constantly monitors the transport amount of the medium Md. Further, the controller 51 stores the timing at which the detection sensor 31 detects the reference mark mrk of the medium Md. As a result, the controller 51 knows how much the medium Md has been transported since the detection mark 31 was detected by the detection sensor 31.

  FIG. 5 is an explanatory diagram of a nozzle configuration in the head according to the present embodiment. FIG. 5 shows a state where the nozzle row is visually recognized from the upper surface of the head. The head 41 is composed of four nozzle rows. Each nozzle row has 180 nozzles from nozzle number # 1 to nozzle number # 180. In FIG. 5, nozzle numbers # 1 to # 180 are assigned from the nozzles on the downstream side in the medium conveyance direction toward the nozzles on the upstream side. The pitch P between these nozzles is 180 dpi.

  The four nozzle arrays are a yellow ink nozzle array that ejects yellow ink Y, a magenta ink nozzle array that ejects magenta ink M, a cyan ink nozzle array C that ejects cyan ink C, and a black that ejects black ink K. Ink nozzle row K is included.

  In the printer 1, based on print data including image data, ink is ejected intermittently from the head 41 that moves in the movement direction by the carriage 43 to form a dot row (raster line) along the movement direction on the medium. The operation (hereinafter sometimes referred to as “pass”) and the transport operation of transporting the medium in the transport direction by the paper transport unit 20 are alternately repeated. As a result, dots can be formed at positions different from the positions of the dots formed by the previous dot formation operation, and a two-dimensional image can be formed on the paper.

<About print data>
Print data transmitted from the computer 110 to the printer 1 is created according to a printer driver stored in the memory 114 of the computer 110. The outline of the print data creation process will be described below.

  First, in the resolution conversion process, RGB image data output from various application programs (here, RGB image data is used to distinguish it from image data for printing described later) is converted to a resolution for printing on a medium. To do. The RGB image data after resolution conversion processing is 256-gradation RGB data represented by an RGB color space.

Next, RGB data is converted into CMYK data corresponding to the ink color of the printer 1 by color conversion processing.
Thereafter, data of 256 gradations having a high gradation number is converted into data having a low gradation number that can be formed by the printer 1 by halftone processing. The printer 1 according to the present embodiment converts the data into four gradation data so that three types of dots can be formed. In this way, pixel data having four gradation data for each ink color is generated for each pixel. Here, such a set of pixel data is referred to as image data. A set of pixel data (null data) that forms a blank without forming any dots is also called image data. A raster line corresponding to Mtotal in FIG. 8 to be described later is also composed of null data.

  Finally, in the rasterizing process, the above image data is rearranged for each data in the order to be transferred to the head 41. The data that has undergone these processes is transmitted as print data to the printer 1 by the printer driver together with command data (such as a conveyance amount) corresponding to the printing method.

=== About interlaced printing ===
The printer 1 of this embodiment normally performs interlaced printing. In interlaced printing, raster lines of other passes are formed between raster lines recorded in one pass. In interlaced printing, since the printing method at the beginning and end of printing is different from normal printing, it will be described separately for normal printing, leading edge printing, and trailing edge printing.

  6A and 6B are explanatory diagrams of normal printing. 6A shows the state of pass n to pass n + 3, and FIG. 6B shows the state of pass n to pass n + 4. For convenience of explanation, the head 41 (nozzle row) is drawn as if it moves relative to the medium in order to reduce the number of nozzles in the nozzle row and to indicate the relative position between the nozzle row and the medium. In the figure, the nozzles indicated by black circles are ink ejection nozzles, and the nozzles indicated by white circles are ink non-ejection nozzles. Further, in the figure, the dots indicated by black circles are dots formed in the last pass, and the dots indicated by white circles are dots formed in the previous pass.

  In normal printing of interlaced printing, each time the medium is transported at a certain transport amount F in the transport direction, each nozzle records a raster line immediately above (the front end side) the raster line recorded in the immediately preceding pass. To do. In order to perform recording with a constant conveyance amount in this way, (1) the number of nozzles N (integer) that can eject ink is relatively prime to k (nozzle pitch P = k · D); (2) The transport amount F must be set to N · D. Here, N = 7, k = 4, and F = 7 · D. In such normal printing, the carry amount F is larger than the nozzle pitch P.

  However, in such normal printing, there are places where a raster line is not formed at the beginning and end of printing. For this reason, a printing method different from the normal printing is performed in the leading edge printing and the trailing edge printing.

  FIG. 7 is an explanatory diagram of leading edge printing and trailing edge printing. The first five passes are leading edge printing, and the last five passes are trailing edge printing. In front-end printing, the medium is transported with a transport amount (1 · D or 2 · D) smaller than the transport amount (7 · D) during normal printing. In front-end printing and rear-end printing, the nozzles that eject ink are not constant. As a result, a plurality of raster lines arranged continuously in the transport direction can be formed at the beginning and end of printing.

  The arrangement of raster lines in an area printed by normal printing (hereinafter referred to as normal printing area) has regularity for each of the same number of raster lines as the number of ink ejectable nozzles (N = 7 in this case). The first to seventh raster lines formed by normal printing are formed by nozzles # 3, # 5, # 7, # 2, # 4, # 6, and # 8, respectively. The seventh and subsequent raster lines are also formed by the nozzles in the same order. On the other hand, the arrangement of raster lines in the area printed by leading edge printing (hereinafter referred to as leading edge printing area) and the area printed by trailing edge printing (hereinafter referred to as trailing edge printing area) is compared with the raster line in the normal printing area. It is difficult to find regularity. However, at least the transport amount F in front end printing / rear end printing is smaller than the nozzle pitch P.

  FIG. 8 is an explanatory diagram of the medium Md used in the present embodiment. FIG. 8 shows the medium Md and its transport direction. Further, the reference mark mrk formed on the medium Md is indicated by a rectangle, and the image Img formed on the medium Md is indicated by a left-down hatching.

  Further, the head 41 is shown as a relative position with respect to the conveyance direction of the medium Md. In the printer 1, the medium Md is intermittently transported in the transport direction. When the conveyance of the medium Md is stopped, the head 41 moves in the movement direction intersecting the conveyance direction and ejects ink to form an image Img. At this time, the formed image does not overlap with the reference mark mrk in the transport direction. Ink is not ejected onto the raster line of the reference mark.

  Further, the formed image overlaps the reference mark mrk in the moving direction of the head 41. In this way, since the reference mark can be positioned near the second page image, the print start position of the second page image can be corrected with high accuracy.

  The reason why the reference mark mrk is provided is as follows. For example, in the case of a sealing medium, there is a case where the seal is die-cut in a label shape on which an image is formed. When such a die-cut medium is continuously fed from the roll body, an image may not be appropriately formed on the die-cut label unless the printing position is adjusted with high accuracy. For example, there arises a problem that the image protrudes from the label shape. Also, such misregistration accumulates. Accordingly, since it is necessary to correct the printing position, in the present embodiment, the reference mark mrk is provided, and the position of the start raster of the image is dynamically corrected based on the position where the reference mark mrk is detected. .

  Attention is paid to the printing around the second reference mark mrk from the paper surface of FIG. In the printing of the reference example, the print data is sent as one job for each page. For this reason, the printing process is completed for each page. The print processing for one job includes the above-described front end printing, normal printing, and rear end printing. For this reason, since the leading edge printing is newly started between the pages after the trailing edge printing is completed, nozzles that are not used in the head 41 are generated in both the trailing edge printing and the leading edge printing.

  In FIG. 8, the width of the nozzles not used in the trailing edge printing (nozzles that do not eject ink) is the first margin mgn1, and the width of the nozzles not used in the leading edge printing is indicated by the second margin mgn2. The total width of these two is indicated by the total margin Mtotal. Since printing cannot be performed with the width of the total margin Mtotal, this portion is reliably broken paper. Note that raster line image data in which no dots are formed is inserted in the Mtotal width in which no image is formed.

  FIG. 9 is an explanatory diagram of the relative position of the head to the medium in the reference example. In the reference example in FIG. 9, one page is printed by leading edge printing and normal printing. That is, one job is composed of leading edge printing and normal printing.

  FIG. 9 shows the head 41 and the reference mark mrk. Since the head 41 moves relative to the medium, the head 41 is illustrated as moving in the opposite direction to the conveyance direction of the medium. Each path of the head 41 is shown in the upper part of the figure. The head 41 has seven nozzles. This is shown with a reduced number of nozzles for ease of explanation. Among these nozzles, nozzles that eject ink are shown in a circle, and nozzles that do not eject ink have an “X” mark on the nozzle.

  Here, an image for one page is formed in eight passes. The first pass (first pass and ninth pass) for forming an image of each page is a front-end printing pass. Accordingly, the transport amount that shifts from the first pass to the second pass (the ninth pass to the tenth pass) is small, and is a transport amount corresponding to 0.5 nozzle pitch. On the other hand, in the second pass to the eighth pass (from the 10th pass to the 16th pass), the respective carry amounts are larger than this, and the carry amount is 3.5 nozzle pitches.

  When the first page is printed and the second page is transferred, the transport amount is at least the width from the # 1 nozzle to the # 7 nozzle, that is, the most downstream nozzle and the most upstream nozzle. It is more than the width between.

  As described above, in order to shift to the printing of the next page, the conveyance amount larger than the width between the most downstream nozzle and the most upstream nozzle is required because the data transmission unit is a job unit (that is, every page). Because it is. As described above, since printing of each page is independent, when printing of the first page is completed, the printing between the most downstream nozzle and the most upstream nozzle is not performed so as not to affect the image of the first page. The medium Md is transported beyond the width of the first and the second page is started to be printed.

  In the above reference example, the front end printing and the normal printing have been described. However, even in the case of the printing including the rear end printing, the same problem occurs when the print processing is independent for each job.

  FIG. 10 is an explanatory diagram of the printing process of the reference example when performing the leading edge printing process and the trailing edge printing process. In FIG. 10, the medium Md and the head 41 are shown. Actually, the medium Md is transported, but since the positions of the medium Md and the head 41 are relative to each other, the head 41 is also shown here as moving relative to the medium Md. ing.

  In FIG. 10, the head 41 indicated by the left-down hatching with a small number of lines is performing front end printing. Further, the head 41 indicated by the left-down hatching with a large number of lines is normally printing. Further, the head 41 indicated by the right-downward hatching with a small number of lines performs the rear end printing.

  Thus, in the printing process of the reference example, leading edge printing is started with reference to the reference mark mrk, and then normal printing and trailing edge printing are performed. Then, it is assumed that printing of one page (one job) is completed when the trailing edge printing is completed. Then, printing for the next page (one job) is started with the next reference mark mrk as a reference. At this time, since printing is performed with one page as one unit, the medium is transported beyond the width between the most downstream nozzle and the most upstream nozzle after the printing of the first page is completed. Then, printing of the second page is started.

  As described above, there are nozzles that are not used for printing on the downstream side of the head 41 in front-end printing and the upstream side of the head 41 in rear-end printing. That is, since an image cannot be formed at a position corresponding to a nozzle that is not used for printing, this portion (a portion corresponding to Mtotal) is reliably broken paper. Further, since the throughput is low in the leading edge printing and the trailing edge printing, the printing speed is also lowered.

  FIG. 11 is an explanatory diagram of the printing process of the reference example. As described above, the throughput decreases when leading edge printing and trailing edge printing are performed. Therefore, it is conceivable that all image formation is performed by normal printing in order to improve throughput. FIG. 11 is an explanatory diagram of a reference example when all image formation is performed by normal printing.

  In the figure, the head 41 which has a large number of lines and is applied with left-down hatching performs normal printing. In normal printing in interlaced printing, the raster line is filled with dots without a gap in the vicinity of the center of the nozzle row of the head 41 in the first pass (see FIG. 6). For this reason, the position of the head 41 in the first pass is a position where the vicinity of the center of the nozzle row overlaps with the position of the reference mark mrk in the transport direction. Thereafter, printing of the first page is completed while carrying with the same carry amount. When the printing for one page is completed, the medium Md moves beyond the width between the most downstream nozzle and the most upstream nozzle of the head 41 and starts printing the second page.

  As described above, the printing throughput is improved because only the normal printing is performed without performing the leading edge printing and the trailing edge printing. However, since the transport amount of the medium Md after the completion of the first page and before the start of the second page is large, and there are many nozzles that cannot be used for printing at the upper and lower ends of each page, the area of damaged paper (Mtotal) is also large. Become.

  FIG. 12 is an explanatory diagram of a printing process of a reference example in the case of backfeeding. In FIG. 12, as in FIG. 11, the head 41 indicated by the left-down hatching with a large number of lines performs normal printing. However, with the above-described method of FIG. 11, the Mtotal that becomes a waste paper has increased, and here, after the printing of the first page is completed, the medium is transported in the direction opposite to the transport direction (back feed). I am letting.

  Since the width of Mtotal can be reduced by back-feeding in this way, it is possible to reduce waste paper. However, since time for backfeeding is required, the printing throughput as a whole eventually decreases.

  As described above, with the printing method as described above, it is difficult to suppress a decrease in the speed of the entire image formation while reducing the margin between pages. Therefore, in the present embodiment, the following method is used to suppress a decrease in the speed of the entire image formation while reducing the margin between pages.

  FIG. 13 is an explanatory diagram of print processing in the present embodiment. Here too, the head 41 indicated by the left-down hatching with a small number of lines is performing front end printing. Further, the head 41 indicated by the left-down hatching with a large number of lines is normally printing.

  Here, for easy explanation, printing per page is performed in five passes. The first two passes are leading edge printing. The subsequent 3rd to 5th passes are normal printing.

  When the fifth pass, which is the final pass for printing one page, is completed, the medium Md is transported to print the second page. In the present embodiment, the transport amount (transition transport amount) by which the medium Md is transported here is smaller than the width from the most upstream nozzle to the most downstream nozzle. As described above, as a method of reducing the transport amount when shifting from the first page to the second page, the job data of the first page is read and the job data of the second page is pre-read. Then, it is conceivable to reconstruct the image data so that the position of the start raster of the second page can be started from a position with reference to the reference mark mrk.

  By doing so, it is possible to suppress a decrease in the speed of the entire image formation while reducing the amount of damaged paper generated between pages.

  FIG. 14 is an explanatory diagram of the relative position of the head to the medium in the present embodiment. Here, a specific nozzle position when leading edge printing and trailing edge printing are performed in the present embodiment will be described.

  In this case as well, since the head 41 moves relative to the medium, it is shown as moving in the opposite direction to the medium transport direction. Each pass of the head 41 is shown in the upper part of the figure, but printing is performed with 8 passes per page. The head 41 has seven nozzles. This is also shown with a reduced number of nozzles for ease of explanation. Among these nozzles, nozzles that eject ink are shown as circles, and nozzles that do not eject ink are indicated by an “X” mark on the nozzles.

  The relative movement of the head 41 shown in FIG. 14 differs from that in FIG. 9 between the pass for completing the printing of the first page (8th pass) and the pass for starting the printing of the second page (9th pass). This is the medium transport amount (transition transport amount). In the case of the reference example shown in FIG. 9, the conveyance is performed more than the distance between the most upstream nozzle and the most downstream nozzle. In the embodiment shown in FIG. It has become. That is, the amount of movement is less than the distance between the most upstream nozzle and the most downstream nozzle.

  For this reason, it is possible to reduce the waste paper generated between pages. In addition, since the leading edge printing is started immediately in the ninth pass, it is possible to suppress a decrease in the speed of the entire image formation. Further, as described above, the transition transport amount is corrected so that the start raster position of the ninth pass starts from the upstream end in the transport direction of the reference mark mrk in accordance with the detection position of the reference mark mrk. . Thereby, an image can be formed at an appropriate position on the medium Md.

  FIG. 15 is an explanatory diagram of the relative position of the head with respect to the medium when the rear end processing is performed in the present embodiment. In FIG. 13, the method of performing printing for one page by front-end printing and normal printing has been described. However, in the method illustrated in FIG. 15, printing for one page is performed by front-end printing, normal printing, and rear-end printing.

  Also in FIG. 10 of the above-mentioned reference example, leading edge printing, normal printing, and trailing edge printing were performed. However, in FIG. 15, the difference from FIG. Is the transport amount (transition transport amount) of the medium with respect to the pass at which printing is started. In the case of the reference example shown in FIG. 10, the conveyance more than the distance between the most upstream nozzle and the most downstream nozzle is performed. However, even in the embodiment shown in FIG. The conveyance amount is less than the distance between the nozzle and the most downstream nozzle.

  As described above, even when the trailing edge printing is included, it is possible to reduce the waste paper generated between the pages. Further, since processing such as back feed is not performed, it is possible to suppress a decrease in the speed of the entire image formation.

=== Other Embodiments ===
In the above-described embodiment, the printer 1 has been described as the liquid ejecting apparatus. However, the present invention is not limited to this, and other fluids (liquids, liquids in which particles of functional materials are dispersed, gels, and the like) are not limited thereto. Such a fluid can also be embodied in a liquid ejection device that ejects or ejects the fluid. For example, color filter manufacturing apparatus, dyeing apparatus, fine processing apparatus, semiconductor manufacturing apparatus, surface processing apparatus, three-dimensional modeling machine, gas vaporizer, organic EL manufacturing apparatus (especially polymer EL manufacturing apparatus), display manufacturing apparatus, film formation You may apply the technique similar to the above-mentioned embodiment to the various apparatuses which applied inkjet technology, such as an apparatus and a DNA chip manufacturing apparatus. These methods and manufacturing methods are also within the scope of application.

  The above-described embodiments are for facilitating the understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof.

<About the head>
In the above-described embodiment, ink is ejected using a piezoelectric element. However, the method for discharging the liquid is not limited to this. For example, other methods such as a method of generating bubbles in the nozzle by heat may be used.

100 printing system,
1 printer,
20 paper transport unit,
40 recording units, 41 heads,
51 control unit, 52 drive signal generation unit,
70 legs, 80 operation panel, 90 housing,
110 computers,
112 interface, 113 CPU, 114 memory,
120 display device, 130 input device, 140 recording / reproducing device,

Claims (8)

A transport unit that performs a transport operation of transporting the medium in the transport direction;
A sensor for detecting a position of a reference mark in the conveyance direction of the medium;
A nozzle row having a plurality of nozzles for ejecting ink onto the medium in a direction along the transport direction, the nozzle row performing an ejection operation of ejecting ink onto the medium by moving in an intersecting direction intersecting the transport direction; ,
A controller that controls the ejection operation and the transport operation;
The control unit includes a final ejection operation for forming an image of the first page, and a first ejection operation for a second page, which is the next page of the first page, out of the transport amount of the medium in the transport operation. And correcting the transition transport amount of the transport operation between and based on the detection position of the reference mark,
The printing apparatus in which the transition conveyance amount is shorter than an interval between the most upstream nozzle and the most downstream nozzle in the conveyance direction in the nozzle row.   The printing apparatus according to claim 1, wherein the image of the first page is formed on the downstream side of the reference mark in the transport direction, and the image of the second page is formed on the upstream side of the reference mark. .   The printing apparatus according to claim 1, wherein the image of the first page and the image of the second page do not overlap the reference mark in the transport direction.   The printing apparatus according to claim 1, wherein the image of the first page and the image of the second page overlap with the reference mark in the intersecting direction.   The conveyance amount in the conveyance operation between the last injection operation and the injection operation immediately before the last injection operation is larger than the nozzle pitch in the nozzle row. Printing.   The conveyance amount in the conveyance operation between the last injection operation and the injection operation immediately before the last injection operation is less than the nozzle pitch in the nozzle row. Printing device.   The conveyance amount in the conveyance operation between the first injection operation and the injection operation immediately after the first injection operation is less than the nozzle pitch in the nozzle row. Printing device. Detecting a position of the reference mark in the conveyance direction of the medium;
Moving the nozzle row in the intersecting direction intersecting the transport direction to eject ink, and performing a final ejecting operation to form an image of the first page;
Performing a transport operation for transporting the medium in the transport direction by a transition transport amount;
Moving the nozzle row in the intersecting direction to eject ink and performing a first ejection operation to form an image of a second page that is the next page of the first page;
Including
The transition carry amount is corrected based on the detection position of the reference mark,
The printing method, wherein the transition conveyance amount is shorter than an interval between a most upstream nozzle and a most downstream nozzle of the conveyance amount in the nozzle row.

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