JP2012011702A - Apparatus and method for ejecting fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation of quality of an image.SOLUTION: A liquid ejection apparatus, when forming main images by a first nozzle train and forming background images by second nozzle train in piles on an medium: repeats in order, outward trip motion to move relatively the nozzle train and the medium to one direction of the moving direction, return trip motion to relatively move the nozzle train and the medium to another direction of the moving direction, and transfer motion to carry relative position of the nozzle train and the medium to a carrying direction which intersects the moving direction; makes part of the first nozzle train which forms the main image, and part of carrying direction upstream side out of part of the second nozzle trains which form the background form the image in a predetermined region of the medium in advance to part of the downstream side; ejects fluid from the nozzle at least by one of the outward trip motion and the return trip motion in order to form the main image, and ejects the fluid from the nozzle at least by one of the outward trip motion and the return trip motion in order to form the background image.

Description

  The present invention relates to a fluid ejecting apparatus and a fluid ejecting method.

As one of the fluid ejecting apparatuses, there is an ink jet printer (hereinafter referred to as a printer) including a nozzle row in which nozzles that eject ink (fluid) to a medium are arranged in a predetermined direction. As a printer, there is a printer that repeats an image forming operation for ejecting ink from a nozzle while moving a nozzle row in a moving direction intersecting a predetermined direction, and a transport operation for transporting a medium to the nozzle row in a transport direction that is a predetermined direction. Are known.
In the printer, in order to print the main image and the background image on top of each other, two nozzle arrays that print the background image are arranged in the movement direction, and the main image is displayed between the two nozzle arrays that print the background image. There is a printer in which nozzle rows to be printed are arranged (see, for example, Patent Document 1).

JP 2003-285422 A

However, in the above-described printer, for example, the main image is printed immediately after the background image is printed. For this reason, a sufficient drying time for the background image cannot be ensured, and the image is blurred or mixed. As a result, the image quality of the printed image is degraded.
Accordingly, an object of the present invention is to suppress image quality deterioration of an image.

The main invention for solving the above problems is that (A) a first nozzle row in which nozzles for ejecting a first fluid are arranged in a predetermined direction, and (B) nozzles for injecting a second fluid are arranged in the predetermined direction. And a second nozzle row aligned with the first nozzle row in a moving direction that is a direction intersecting the predetermined direction, (C) formation of a main image by the first fluid, and background by the second fluid When the image formation is performed on the medium, the forward movement operation of relatively moving the first nozzle row, the second nozzle row, and the medium in one of the movement directions; and the first nozzle row And a return path operation for relatively moving the second nozzle row and the medium in the other direction of the moving direction, and a relative position of the medium with respect to the first nozzle row and the second nozzle row on one side in the predetermined direction. The transfer operation to be moved to By repeating the operation, the return path operation, and the transport operation in this order, an image is formed on the medium, and a part of the nozzle group of the first nozzle row that forms the main image and the second image that forms the background image One nozzle group of a part of the nozzle groups of the nozzle row, and using the one nozzle group located on the other side in the predetermined direction with respect to the other nozzle group, precedes the other nozzle group. An image is formed on a predetermined area of the medium, and a fluid is ejected from the nozzle during at least one of the forward operation and the backward operation to form the main image, and the background image In order to form the fluid ejecting apparatus, the fluid ejecting apparatus includes: (D) a control unit that ejects fluid from the nozzle during at least one of the forward path operation and the backward path operation.
Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

1 is an overall configuration block diagram of a printer. It is a perspective view of a printer. It is a figure which shows the arrangement | sequence of the nozzle provided in the lower surface of a head. It is a figure explaining the printing mode which a printer has. It is a figure explaining the printing method which a printer implements. It is a figure which shows the decision flow of a printing method. 6 is a diagram illustrating a printing method according to the first exemplary embodiment. FIG. It is a figure explaining the printing method of a comparative example. FIG. 10 is a diagram illustrating a printing method according to a second embodiment. FIG. 10A is a diagram for explaining a printing method in the back printing / white use mode in the second embodiment, and FIG. 10B is a diagram for explaining interlaced printing in the second embodiment. FIG. 10 is a diagram illustrating a printing method according to a third embodiment.

=== Summary of disclosure ===
At least the following will become apparent from the description of the present specification and the accompanying drawings.

That is, (A) a first nozzle row in which nozzles for ejecting a first fluid are arranged in a predetermined direction, and (B) nozzles for injecting a second fluid are arranged in the predetermined direction and intersect the predetermined direction. A second nozzle row aligned with the first nozzle row in a moving direction, which is a direction, and (C) formation of a main image by the first fluid and formation of a background image by the second fluid are superimposed on the medium. The first nozzle row, the second nozzle row, and the medium, and the medium is moved forward in one direction of the movement direction, and the first nozzle row, the second nozzle row, and the medium. And a transporting operation for moving the relative position of the medium to the one side in the predetermined direction with respect to the first nozzle row and the second nozzle row, Outward movement, the backward movement, the conveyance By repeating the order of operation, an image is formed on the medium, and a part of the nozzle group of the first nozzle array that forms the main image and a part of the nozzle group of the second nozzle array that forms the background image One nozzle group, and using the one nozzle group located on the other side in the predetermined direction with respect to the other nozzle group, the first nozzle group is placed in a predetermined area of the medium before the other nozzle group. In order to form the main image, in order to form the main image, fluid is ejected from the nozzle during at least one of the forward operation and the backward operation, and the forward image is formed to form the background image. A fluid ejecting apparatus comprising: (D) a control unit that ejects fluid from the nozzle during at least one of an operation and a return path operation.
According to such a fluid ejecting apparatus, it is possible to lengthen the drying time of the lower layer image of the main image and the background image, and to suppress bleeding of the image. As a result, image quality deterioration of the image can be suppressed.

In the fluid ejecting apparatus, the one nozzle group that performs image formation on a predetermined area of the medium ejects fluid at least during the forward operation.
According to such a fluid ejecting apparatus, the return path operation can be used for the drying time of the lower layer image, and the drying time of the lower layer image can be lengthened.

In this fluid ejecting apparatus, the other nozzle group that will later form an image on a predetermined area of the medium ejects fluid at least during the return path operation.
According to such a fluid ejecting apparatus, the forward movement operation can be used for the drying time of the lower layer image, and the drying time of the lower layer image can be lengthened.

In this fluid ejecting apparatus, at least one of the time required for one forward operation and the time required for one return operation is longer than the time required for one transport operation.
According to such a fluid ejecting apparatus, when the time required for the forward path operation or the backward path operation becomes the drying time of the lower layer image, the drying time of the lower layer image becomes longer.

In this fluid ejecting apparatus, the background is also used by using the nozzles in the first nozzle row that have the same position in the predetermined direction as the nozzle group that is part of the second nozzle row that forms the background image. Forming an image.
According to such a fluid ejecting apparatus, a desired background image can be formed.

In addition, a first nozzle row in which nozzles for ejecting the first fluid are arranged in a predetermined direction, and a nozzle in which the second fluid is ejected are arranged in the predetermined direction and in a moving direction that is a direction intersecting the predetermined direction. A fluid ejecting method for a fluid ejecting apparatus having a second nozzle array aligned with the first nozzle array, wherein a main image is formed by the first fluid and a background image is formed by the second fluid. A forward operation for relatively moving the first nozzle row, the second nozzle row, and the medium in one direction of the movement direction, and the first nozzle row and the second nozzle, A return path operation in which the row and the medium are relatively moved in the other direction of the movement direction, and a transport operation in which the relative position of the medium with respect to the first nozzle row and the second nozzle row is moved to one side in the predetermined direction. And the forward movement The second nozzle that forms the background image and the partial nozzle group of the first nozzle row that forms an image on the medium by repeating the return path operation and the transport operation in this order. One nozzle group of a part of the nozzle groups in the row, and using the one nozzle group located on the other side in the predetermined direction with respect to the other nozzle group, before the other nozzle group Forming an image on a predetermined area of the medium, and ejecting fluid from the nozzle during at least one of the forward operation and the backward operation for forming the main image, In order to form the fluid, the fluid is ejected from the nozzle during at least one of the forward operation and the backward operation.
According to such a fluid ejection method, it is possible to lengthen the drying time of the lower layer image of the main image and the background image, it is possible to suppress bleeding of the image and the like, and it is possible to suppress image quality deterioration of the image.

=== About the printing system ===
Hereinafter, an embodiment will be described by taking as an example a printing system in which an inkjet printer (hereinafter referred to as a printer) and a computer are connected.

  FIG. 1 is a block diagram of the overall configuration of the printer 1. FIG. 2 is a perspective view of the printer 1. The computer 60 is communicably connected to the printer 1 and outputs print data for causing the printer 1 to print an image to the printer 1. The computer 60 is installed with a program (printer driver) for converting image data output from the application program into print data. The printer driver is recorded on a recording medium (computer-readable recording medium) such as a CD-ROM or can be downloaded to a computer via the Internet.

  The controller 10 is a control unit for controlling the printer 1. The interface unit 11 is for transmitting and receiving data between the computer 60 and the printer 1. The CPU 12 is an arithmetic processing unit for controlling the entire printer 1. The memory 13 is for securing an area for storing a program of the CPU 12, a work area, and the like. The CPU 12 controls each unit by the unit control circuit 14. The detector group 50 monitors the situation in the printer 1, and the controller 10 controls each unit based on the detection result.

The transport unit 20 feeds the medium S to a printable position, and transports the medium S by a predetermined transport amount in the transport direction during printing.
The carriage unit 30 is for moving the head 41 in a movement direction that intersects the conveyance direction, and includes a carriage 31.

  The head unit 40 is for ejecting ink onto the medium S and has a head 41. The head 41 is moved in the movement direction by the carriage 31. A plurality of nozzles that are ink ejecting units are provided on the lower surface of the head 41, and each nozzle is provided with a pressure chamber (not shown) containing ink.

  FIG. 3 is a diagram illustrating an arrangement of nozzles provided on the lower surface of the head 41. In addition, the figure is the figure which looked at the nozzle virtually from the upper surface of the head 41. FIG. On the lower surface of the head 41, five nozzle rows in which 180 nozzles are arranged at a predetermined interval D in the transport direction are formed. As shown in the figure, black nozzle row K for ejecting black ink, cyan nozzle row C for ejecting cyan ink, magenta nozzle row M for ejecting magenta ink, yellow nozzle row Y for ejecting yellow ink, and white ink are ejected. White nozzle rows W are arranged in the movement direction. Note that the 180 nozzles in each nozzle row are numbered sequentially from the nozzles on the downstream side in the transport direction (# 1 to # 180).

  In such a printer 1, an image forming operation in which ink droplets are intermittently ejected from the head 41 moving along the moving direction to form dots on the medium, and the medium is conveyed in the conveying direction with respect to the head 41. The conveyance operation is repeated. By doing so, dots can be formed by a subsequent image forming operation at a position on the medium different from the position of the dot formed by the previous image forming operation, and a two-dimensional image is printed on the medium. can do.

=== About print mode ===
FIG. 4 is a diagram illustrating a printing mode that the printer 1 of the present embodiment has. The printer 1 has a “color mode” in which only a main image (color image or monochrome image) printed with four color inks (YMCK) is printed on a medium, and a white background image with a white ink and a main image superimposed on the medium. An image is printed on the medium in any one of the “white use mode” to be printed on. By providing a white background image on the background of the main image as in the white usage mode, an image with good color development can be printed particularly when the medium is not white. In addition, when the medium is transparent, it is possible to prevent the opposite side of the printed matter from being seen through by printing the main image and the background image in an overlapping manner.

  Further, the printer 1 prints an image on the medium in one of the front printing mode and the back printing mode. The front printing mode is a mode for printing an image so that the main image is viewed from the printing surface side, and the back printing mode is for the main image to be viewed from the surface opposite to the printing surface through the medium. This is a mode for printing an image. Therefore, the reverse printing mode is performed when the medium has transparency. Since only the main image is printed on the medium in the color mode, the main image is printed directly on the medium in both the front printing mode and the back printing mode. On the other hand, since the main image and the background image are overprinted in the white use mode, the background image is printed first with respect to a predetermined area of the medium in the front printing mode, and the main image is printed on the background image. Conversely, in the reverse printing mode, the main image is printed first on a predetermined area of the medium, and the background image is printed on the main image.

  As described above, the printer 1 has four printing modes: a front printing / color mode, a back printing / color mode, a front printing / white use mode, and a back printing / white use mode.

The term “white” in this specification is not limited to white in the strict sense that is the surface color of an object that reflects 100% of all wavelengths of visible light, but is commonly known as “white”. , Including a color called white. “White” means, for example, (1) color measurement mode: spot color measurement, light source: D50, backing: Black, printing medium: transparent film using x-rite colorimeter eye-onePro When colored, the mark in the L ^* a ^* b ^* color space is on the a ^* b ^* plane and within the circumference of the radius 20 and within the hue range represented by an L ^* value of 70 or more. (2) When using a Minolta colorimeter CM2022 and measuring in the measurement mode D502 ° field of view, SCF mode, and white background, the label in the L ^* a ^* b ^* color space is a ^* b ^* Whether the color is within the circumference of a circle having a radius of 20 on the plane and the inside thereof, and the color within the hue range represented by an L ^* value of 70 or more. (3) As described in Japanese Patent Application Laid-Open No. 2004-306591 The color of the ink used as the background of the image. Is not limited to the pure white if Re.

  When a background image is printed using only white ink, the color of the white ink itself becomes the color of the background image. However, even in the case of ink called white ink, the color of white is slightly different depending on the ink material. Therefore, a background image having a color different from the color desired by the user may be printed depending on the white ink used. In addition, a background image having a slight chromatic color instead of simple white may be desired. Accordingly, the printer 1 of the present embodiment prints a desired white background image (adjusted white background image) by appropriately using a small amount of four-color ink (YMCK) together with white ink. By doing so, conversely, when the white ink has a slight color, the background image can be printed together with the ink that cancels the color, and the background image can be brought close to an achromatic color.

  Print data for causing the printer 1 to print a desired white background image may be stored in advance by the printer 1 or may be created by a printer driver. When a user selects a desired background image color by, for example, looking at the monitor of the printer 1 or the computer screen, the printer driver generates the background image print data corresponding to the selected color. It is good to.

=== Printing method ===
FIG. 5 is a diagram illustrating a printing method performed by the printer 1 of the present embodiment. The printer 1 prints an image on a medium by one of the “first printing method” and the “second printing method”. Hereinafter, an operation in which the medium is transported downstream in the transport direction with respect to the head 41 is referred to as a “transport operation”, and an operation in which the head 41 moves in the movement direction is referred to as a “pass”. An operation in which the head 41 moves in one direction relative to the medium (for example, an operation in which the head 41 moves from the right side to the left side) is referred to as an “outward movement operation”, and the head 41 moves in the other direction relative to the medium. The operation of moving to (for example, the operation of moving from the left side to the right side) is referred to as “return trip operation”. That is, the forward movement operation and the backward movement operation are relative movements of the head 41 (nozzle row) and the medium in both directions of movement. The forward path operation refers to an operation in which the carriage 31 moves away from the home position HP shown in FIG. 2, and the backward path operation refers to an operation in which the carriage 31 approaches the home position HP.

  As shown in FIG. 5, in the first printing method, the forward movement operation, the backward movement operation, and the conveyance operation are repeated in order. On the other hand, in the second printing method, the forward movement operation, the conveyance operation, the backward movement operation, and the conveyance operation are repeated in order. That is, in the second printing method, the transport operation is performed between the forward path operation and the backward path operation, whereas in the first printing method, the transport operation is not performed between the forward path operation and the backward path operation. Therefore, in the second printing method, an image is printed both in the forward path operation and in the backward path operation. On the other hand, in the first printing method, an image is printed in at least one of the forward path operation and the backward path operation. That is, in the first printing method, in order to form the main image shown in FIG. 4, ink is ejected from the nozzle row (YMCK) of four colors ink at the time of at least one of the forward operation and the backward operation. In order to form an image, ink is ejected from the white nozzle row W and the four-color ink nozzle row during at least one of the forward pass operation and the return pass operation.

  FIG. 6 is a diagram illustrating a setting flow of the printing method. When the printer driver receives a print command from the user, the printer driver displays a window on the display of the computer 60 or the like, and causes the user to select one of the “white use mode” and “color mode”. Thereafter, the printer driver determines whether or not the white use mode is selected by the user (S01). When the white use mode is selected (S01 → Y), the printer driver sets the printing method of the image that has received the print command to the first printing method (S02).

  On the other hand, when the color mode is selected (S01 → N), the printer driver causes the user to select one of the “first printing method” and the “second printing method” (S03). . When the first printing method is selected by the user (S03 → N), the printer driver sets the printing method of the image that has received the print command to the first printing method (S02). On the other hand, when the second printing method is selected by the user (S03 → Y), the printer driver sets the printing method of the image that has received the print command to the second printing method (S04).

  Thereafter, the printer driver creates print data according to the print mode. For example, when the color mode is set, the printer driver creates only the print data for the main image, and when the white usage mode is set, the printer driver uses the background image as well as the print data for the main image. Print data is also created. Further, the printer driver rearranges the created print data in the order of transfer to the printer 1 according to the print mode and printing method. For example, when the front printing / white usage mode is set, the printer driver rearranges the print data of each image so that the background image is printed before the main image for a predetermined area of the medium. When the first printing method is set, the printer driver rearranges the print data of each image so that the image is printed during at least one of the forward operation and the backward operation. On the other hand, when the second printing method is set, the printer driver rearranges the print data of each image so that the image is printed in both the forward operation and the backward operation.

  Further, the printer driver transmits to the printer 1 data indicating which one of the first printing method and the second printing method is to be performed together with the created print data. When the printer 1 (controller 10) receives the data for performing the first printing method, the printer 1 (the controller 10) repeats the forward operation, the backward operation, and the transport operation in order, and when the data for performing the second printing method is received, The forward path operation, the transfer operation, the return path operation, and the transfer operation are repeated in order.

  In the present embodiment, the user is allowed to select either the white use mode or the color mode, but the present invention is not limited to this. For example, when the print medium is a transparent medium, the printer driver may select the white use mode, and when the print medium is any other medium, the printer driver may select the color mode. .

  In the flow of FIG. 6, in the color mode, the user selects either the first printing method or the second printing method. However, the present invention is not limited to this. If the image is printed by only one of the forward path operation and the backward path operation in the first printing method, the characteristic difference between the forward path and the backward path is eliminated, and a higher quality image can be printed. On the other hand, the second printing method can print an image faster than the first printing method. Therefore, when “Premium mode” is set in the basic settings of the printer 1, the printer driver sets the printing method to the first printing method, and when “Quick mode” is set, the printer driver prints. The method may be set to the second printing method.

<Example 1>
FIG. 7 is a diagram illustrating a printing method according to the first embodiment. Hereinafter, a case where the white use mode is selected by the user and the printer driver sets the printing method to the first printing method will be described. FIG. 7 shows printing in the front printing / white use mode. For the sake of simplicity, the nozzle rows (YMCK) for ejecting the four color inks are collectively referred to as “color nozzle row Co (corresponding to the first nozzle row)”. In the figure, the number of nozzles belonging to each of the color nozzle row Co and the white nozzle row W (corresponding to the second nozzle row) is 10 (# 1 to # 10), and the interval between the nozzles arranged in the transport direction in the nozzle row is D. To do. The nozzles belonging to the color nozzle row Co are indicated by circles, and the nozzles belonging to the white nozzle row W are indicated by triangles. Further, in the actual printer 1, the medium is conveyed downstream in the conveyance direction with respect to the head 41, but the lower diagram in FIG. 7 shows a state in which the head 41 is conveyed upstream in the conveyance direction.

  The upper diagram of FIG. 7 is a diagram illustrating nozzles used for printing each image. When printing in the front printing / white use mode, the nozzles # 1 to # 5 on the downstream side in the transport direction of the color nozzle row Co are used as main image nozzles for printing the main image (black nozzles). , Background image nozzles (Δ) for printing a background image (a background image in which a white color is adjusted) on the nozzles # 6 to # 10 on the upstream side in the transport direction of the white nozzle row W and the color nozzle row Co. ○, white nozzle). The half nozzles (# 1 to # 5) on the downstream side in the transport direction of the white nozzle row W are nozzles that are not used for printing.

  As described above, in the present embodiment, the position in the transport direction of the nozzles (Δ) of the white nozzle row W that prints the background image, and the position in the transport direction of the nozzles (◯) of the color nozzle row Co that also prints the background image. And are equal. Then, in order to print the background image, the white ink and the color ink are ejected in the same pass with respect to the predetermined area of the medium. As a result, white ink and color ink are mixed, and the graininess of the background image can be reduced. Further, the ratio of the color ink constituting the background image is smaller than the ratio of the white ink. However, in order to reduce the graininess of the color ink in the background image, it is preferable to disperse the dots of the color ink as uniformly as possible on the background image. That is, the color ink density (dot density) per unit area of the background image is made smaller than the white ink density (dot density) per unit area of the background image. Therefore, although the ratio of the color ink constituting the background image is smaller than the ratio of the white ink, in the present embodiment, the number of nozzles of the white nozzle row W used for printing the background image and the nozzles of the color nozzle row Co The numbers are made equal (five in FIG. 7). However, the present invention is not limited to this, and the number of nozzles in the color nozzle row Co for printing the background image may be smaller than that in the white nozzle row W.

  7 shows the position in the transport direction of the head 41 for each pass, and shows the color nozzle row Co and the white nozzle row W as one nozzle row. The printing method shown in FIG. 7 is band printing. Band printing is a printing method in which a raster line is not formed in a later pass between raster lines (dot rows along the movement direction) formed in a previous pass. For this reason, one medium conveyance amount corresponds to the width in the conveyance direction of the main image or the background image formed in one pass. In FIG. 7, the amount of medium transported once is half the length of the nozzle row (5D).

  In the present embodiment, when the white use mode is selected by the user, an image is printed by the first printing method. That is, the image is printed by a printing method in which the forward path operation, the backward path operation, and the transport operation are repeated in order. In the first embodiment, it is assumed that both the main image and the background image are printed during one of the forward operation and the backward operation, and no image is printed during the other operation. In FIG. 7, it is assumed that the main image and the background image are printed in the forward operation, and no image is printed in the backward operation. That is, in FIG. 7, the forward operation in which the main image and the background image are printed, the backward operation in which no image is printed, and the transport operation in which the medium is transported by the transport amount 5D are sequentially repeated.

  Specifically, as shown in FIG. 7, first, the background image is printed by the background image nozzle (Δ ○) in the pass operation of pass 1, and the return pass operation of the next pass 2 without the medium being conveyed. After the head 41 has moved in the moving direction, the medium is transported by the transport amount 5D. Thereafter, the main image is printed by the main image nozzle (●) in the forward pass operation of pass 3, the background image is printed by the background image nozzle (Δ △), and then the next medium is not transported. The head 41 moves in the movement direction by the return path operation of pass 4, and the medium is conveyed by the conveyance amount 5D. By doing so, the predetermined area of the medium first faces the background image nozzle (Δ （), and then faces the main image nozzle (●) by the medium being conveyed downstream in the conveyance direction. As a result, the main image is printed on the background image in a predetermined area of the medium.

  Although not shown, in the reverse printing / white use mode, conversely, the half nozzles (# 6 to # 10) on the upstream side in the transport direction of the color nozzle row Co are used as main image nozzles, and the white nozzle row The half nozzles (# 1 to # 5) on the downstream side in the transport direction of W and the color nozzle row Co are set as background image nozzles. By doing so, the predetermined area of the medium first faces the main image nozzles (# 6 to # 10), and then the background image nozzles (# 1 to ##) by the medium being transported downstream in the transport direction. Opposite to 5). As a result, a background image is printed on the main image in a predetermined area of the medium.

  In this way, an image nozzle (equivalent to the background image nozzle / one nozzle group in FIG. 7) to be printed later on the predetermined area of the medium is printed later. It is assumed that the nozzle for the upstream side in the transport direction is more than the nozzle for use (in FIG. 7, corresponding to the main image nozzle and the other nozzle group). By doing so, the main image and the background image can be overlaid and printed in the order corresponding to the front printing mode or the back printing mode. Further, the pass for printing the main image and the pass for printing the background image can be made different for a predetermined area of the medium. Then, an image to be printed later (hereinafter also referred to as an upper layer image) is printed from a pass in which an image to be printed first (hereinafter also referred to as a lower layer image) is printed on a predetermined area of the medium among the main image and the background image. The time to pass, that is, the drying time of the lower layer image can be made relatively long.

  Further, in the present embodiment, the main image and the background image are printed by the first printing method in which the transport operation is not performed between the forward operation and the backward operation. In the first embodiment, of the forward operation and the backward operation, The main image and the background image are printed during one operation (in the forward operation in FIG. 7), and the image is not printed during the other operation (in the backward operation in FIG. 7). By doing so, for example, in the case of the surface printing mode as shown in FIG. 7, a background image that is an image to be printed ahead of the main image and the background image is printed during the forward operation. The printer 1 according to the present embodiment does not perform the other operation (the backward operation in FIG. 7) that does not print an image out of the forward operation and the backward operation at the same time as the transport operation. In this case, the time from the pass for printing the lower layer image to the pass for printing the upper layer image for the predetermined area of the medium is the total time required for the forward path operation or the backward path operation and the time required for the transport operation. In the case of FIG. 7, the drying time of the background image that is the lower layer image is the total time of the time required for the return path operation and the time required for the transport operation.

  FIG. 8 is a diagram illustrating a printing method of a comparative example. In the comparative example, it is assumed that the printing method is set to the second printing method even when the white usage mode is selected by the user. FIG. 8 shows a printing method in the front printing / white use mode. As in the first embodiment (FIG. 7), the nozzles used for printing are the half nozzles (● • # 1 to # 5) on the downstream side in the transport direction of the color nozzle row Co as main image nozzles. The half nozzles (Δ ○ # 6 to # 10) on the upstream side in the transport direction of the nozzle row W and the color nozzle row Co are set as background image nozzles.

  In the second printing method, the forward operation, the transport operation, the return operation, and the transport operation are repeated in order, and an image is printed in both the forward operation and the return operation. Specifically, as shown in FIG. 8, first, the background image is printed by the background image nozzle (Δ （) in the forward pass operation of pass 1, and the medium is transported by the transport amount 5D. Thereafter, in the return pass operation of pass 2, the main image is printed by the main image nozzle (●), and the background image is printed by the background image nozzle (Δ ○). In this case, the drying time of the background image as the lower layer image is only the time required for the transport operation.

  Thus, in the comparative example (FIG. 8), the drying time of the lower layer image is only the time required for the transport operation. On the other hand, in Example 1 (FIG. 7), the drying time of the lower layer image is the total time required for the forward operation or the backward operation and the time required for the conveyance operation. That is, the drying time of the lower layer image can be made longer in Example 1 than in the comparative example.

  This is because the image is printed by the first printing method, and the predetermined area of the medium faces the same nozzle group (for example, the main image nozzle and the background image nozzle) in both the forward operation and the backward operation. This is because it is not necessary to form an image in the forward operation or the backward operation as in the printing method. In other words, in the first printing method, it is possible to form an image only during one of the forward operation and the backward operation, and the other operation can be used for the drying time of the lower layer image. For example, as in the first embodiment, it is assumed that the main image and the background image are printed during one operation of the forward operation and the backward operation, and the image is not printed during the other operation. As a result, the drying time of the lower layer image can be made longer than that of the comparative example by the time required for the other operation, blurring and color mixing of the printed image can be suppressed, and image quality deterioration of the printed image can be suppressed.

  Although not shown, the image may not be printed during the forward operation, and the main image and the background image may be printed during the backward operation. For example, referring to FIG. 7, the main image and the background image are printed in pass 4 and pass 6, and the image is not printed in pass 3 and pass 5. In this case, in the front printing mode, the main image printed after the background image is printed during the backward operation, and in the reverse printing mode, the background image printed after the main image is printed during the backward operation. Will be. Therefore, the forward movement operation can be used for the drying time of the lower layer image. That is, the drying time of the lower layer image is the total time of the time required for the conveyance operation and the time required for the forward operation, and the drying time of the lower layer image can be made longer than that of the comparative example (FIG. 8).

  In the present embodiment, the time required for one forward operation is longer than the time required for one transfer operation, and the time required for one return operation is longer than the time required for one transfer operation. And In this embodiment, in order to print the main image and the background image in different passes with respect to a predetermined area of the medium, an image nozzle to be printed first of the main image and the background image is printed later. The nozzle is located upstream of the image nozzle in the transport direction. Therefore, the nozzle for printing each image is half the length of the nozzle row, and the medium conveyance amount in one conveyance operation is relatively short. On the other hand, in recent years, the demand for large-sized printers has increased. In large-sized printers, the movement distance of the head 41 in the moving direction is long, and the time required for the forward movement and the time required for the backward movement are relatively long. It is. That is, in the comparative example, the time required for a relatively short conveying operation is used for the drying time, whereas in Example 1, the time required for a relatively long forward operation or return operation is used for the drying time. The drying time of Example 1 can be made longer than that of the comparative example. Specifically, the drying time of the lower layer image in Example 1 can be made twice or more the drying time of the lower layer image in the comparative example. Note that at least one of the time required for the forward operation and the time required for the return operation may be longer than the time required for the transport operation.

  In the printer 1 of the present embodiment, as described above, it is assumed that the forward operation, the backward operation, and the transport operation are not performed at the same time even if no image is printed by the forward operation or the backward operation. By doing so, the drying time of the lower layer image in Example 1 can be made longer, and bleeding and color mixing of the printed image can be suppressed. On the other hand, if the forward or backward operation and the transport operation are performed at the same time, not only the drying time of the lower layer image is shortened, but also the control becomes complicated, mechanical vibrations occur, and noise is generated in the drive signal. Or the like, the conveyance accuracy may be reduced.

  Further, as in the comparative example (FIG. 8), even when the second printing method is performed in the white use mode, the image is dried by providing a pause time after printing the image in the forward operation or the backward operation. The time can be lengthened. However, in the case of the white use mode, if the pause time is provided after the image is printed by the forward pass operation or the return pass operation and the pause time is not provided in the color mode, the printing control becomes complicated. Further, in order to provide a pause time, a program or device for counting a predetermined pause time is required.

  In the white use mode, in order to further increase the image drying time, it is preferable to provide an unused nozzle between the main image nozzle and the background image nozzle. By doing so, a path where the image is not printed (pass where the unused nozzle faces the medium) may be provided between the path where the lower layer image is printed and the path where the upper layer image is printed with respect to a predetermined area of the medium. And the drying time of the lower layer image can be further increased. In addition, the length in the transport direction of the region to which the unused nozzle belongs is preferably an integral multiple of the medium transport amount. By doing so, the number of passes between the pass for printing the lower layer image and the pass for printing the upper layer image can be made constant throughout the entire image, and uneven density of the image can be prevented.

  In the white use mode, each image is printed using half of the nozzles belonging to the nozzle row in order to print the main image and the background image in different passes. On the other hand, in the color mode, since only the main image is printed, the main image can be printed using all the nozzles belonging to the nozzle row. By doing so, in the color mode, the image width that can be formed in one pass is larger than in the white use mode, and the printing time can be shortened.

  However, the present invention is not limited to this, and the main image may be printed using only half of the nozzles belonging to the nozzle row in the color mode as in the white use mode. For example, the color nozzle used in the front printing / color mode is the same as the color nozzle used in the front printing / white usage mode (the nozzle on the downstream side in the transport direction), and the color nozzle used in the back printing / color mode is changed to the back side. It may be the same as the color nozzle (nozzle upstream in the transport direction) used in the printing / white use mode. In this case, the optimal print pattern and medium transport control in the front printing / color mode and the front printing / white use mode can be shared, and the optimum printing pattern and medium in the back printing / color mode and back printing / white use mode can be shared. Transport control can be shared. By doing so, in the manufacturing process of the printer 1, it is possible to simplify the process of determining the optimal print pattern and transport operation control method. In addition, it is possible to reduce the memory capacity for storing the optimum print pattern in each mode and information on the medium conveyance control. In addition, since the test print can be performed in the color mode before the actual printing in the white use mode and the image quality of the color image can be confirmed, the consumption of white ink can be suppressed.

<Example 2>
FIG. 9 is a diagram illustrating a printing method according to the second embodiment. The figure shows the state of band printing in the front printing / white use mode, and the nozzles used for printing are the half nozzles (● • # 1 to # 5 on the downstream side in the transport direction of the color nozzle row Co, as in FIG. ) Are the main image nozzles, and the half nozzles (Δ ○ # 6 to # 10) on the upstream side in the transport direction of the white nozzle row W and the color nozzle row Co are the background image nozzles. As described above, in the present embodiment, in the white use mode, an image is printed by the first printing method in which the transport operation is not performed between the forward pass operation and the return pass operation.

  Further, in the second embodiment, the lower layer image that is printed first with respect to the predetermined area of the medium among the main image and the background image is printed by the forward operation that is the operation before the return operation, and the main image and the background image are printed. Among them, an upper layer image to be printed later on a predetermined area of the medium is printed by a backward operation which is an operation after the forward operation. For example, in the front printing mode as shown in FIG. 9, the background image is printed earlier than the main image. Therefore, the background image is printed by the forward operation, and the main image is printed by the backward operation. That is, in the second embodiment, the pass for printing the main image is different from the pass for printing the background image.

  Specifically, as shown in FIG. 9, first, the background image is printed by the background image nozzle (Δ ○) in the forward pass operation of pass 1, and the return pass operation of the next pass 2 without the medium being conveyed. After the head 41 has moved in the moving direction, the medium is transported by the transport amount 5D. Thereafter, the background image is printed by the background image nozzle (Δ ○) in the forward pass operation of pass 3, and the main image is printed by the main image nozzle (●) in the return pass operation of pass 4 without transporting the medium. The

  In this case, the time from the pass for printing the background image as the lower layer image to the pass for printing the main image as the upper layer image for the predetermined area of the medium is the time required for the return operation, the time required for the transport operation, and the forward operation. This is the total time required for. That is, the drying time of the lower layer image is the total time of the time required for the forward operation and the return operation and the time required for the conveyance operation. Therefore, the drying time of the lower layer image can be made longer in Example 2 than in the comparative example shown in FIG. Further, the drying time of the lower layer image can be made longer in the second embodiment than the first embodiment shown in FIG. Therefore, in the second embodiment, it is possible to further suppress the bleeding and color mixture of the print image, and to further suppress the deterioration of the image quality of the print image.

  In the first printing method, since the transport operation is not performed between the forward pass operation and the return pass operation, the same nozzle faces the predetermined area of the medium over two passes of the forward pass operation and the return pass operation. Therefore, in the second embodiment, the lower layer image to be printed first of the main image and the background image is printed in the forward operation to print as soon as possible, and the backward operation to print the upper layer image to be printed later as late as possible. Print with. By doing so, the drying time from the pass for printing the lower layer image to the pass for printing the upper layer image can be made as long as possible, and bleeding and color mixing of the printed image can be suppressed.

  In the first embodiment (FIG. 7), both the main image and the background image are printed by one of the forward operation and the backward operation. Therefore, it is possible to print an image from which the difference in characteristics between the forward path and the backward path is eliminated. On the other hand, in the second embodiment, one of the main image and the background image is printed by the forward operation, and the other is printed by the backward operation. However, also in the second embodiment, the same image is printed by one of the forward path operation and the backward path operation, so that an image from which the characteristic difference between the forward path and the backward path is eliminated can be printed.

  FIG. 10A is a diagram illustrating a printing method in the back printing / white use mode according to the second embodiment. In the reverse printing mode, the main image is printed before the background image for a predetermined area of the medium. Therefore, as shown in FIG. 10A, the half nozzles (● # 6 to # 10) on the upstream side in the transport direction of the color nozzle row Co are used as main image nozzles, and the transport direction of the white nozzle row W and the color nozzle row Co The downstream half nozzles (Δ 側 # 1 to # 5) are set as background image nozzles. In the second embodiment, the lower layer image is printed by the forward operation, and the upper layer image is printed by the backward operation. Therefore, in the reverse printing mode, the main image is printed by the forward operation, and the background image is printed by the backward operation. By doing so, the drying time of the lower layer image becomes the total time of the time required for the forward operation and the backward operation and the time required for the conveyance operation, and the drying time is longer than that of the comparative example (FIG. 8) or Example 1 (FIG. 7). can do.

  FIG. 10B is a diagram illustrating interlaced printing according to the second embodiment. Up to this point, band printing has been described as an example. However, the present invention is not limited to this, and for example, interlaced printing may be performed. Interlaced printing is a printing method in which raster lines are formed in another pass between raster lines formed in a certain pass. That is, in interlace printing, the print resolution in the transport direction is higher than in band printing. In FIG. 10B, for example, two star lines are formed in pass 2 and pass 3 between the raster lines formed by nozzles # 9 and # 10 in pass 1. Therefore, in the interlaced printing in FIG. 10B, the medium conveyance amount is 5D / 3, which is shorter than the medium conveyance amount 5D in the band printing in FIG. Therefore, in interlaced printing, a predetermined area of the medium is a nozzle between a pass for printing a lower layer image (background image in FIG. 10B) and a path for printing an upper layer image (main image in FIG. 10B). It is possible to provide a path that is not opposite to the path. Therefore, the interlaced printing can make the lower layer image drying time longer than the band printing. Conversely, it can be said that the present invention is more effective when a pass that does not face the nozzle cannot be provided between a pass for printing the lower layer image and a pass for printing the upper layer image, as in band printing.

<Example 3>
FIG. 11 is a diagram illustrating a printing method according to the third embodiment. The figure shows the state of band printing in the front printing / white use mode. The nozzles used for printing are the half nozzles (● # 1 to # 5) on the downstream side in the conveyance direction of the color nozzle row Co as main image nozzles, and the upstream side in the conveyance direction of the white nozzle row W and the color nozzle row Co. The half nozzles (.DELTA..multidot. # 6 to # 10) are used as background image nozzles. As described above, in the present embodiment, in the white use mode, an image is printed by the first printing method in which the transport operation is not performed between the forward pass operation and the return pass operation.

  Furthermore, in the third embodiment, one of the main image and the background image is printed in two passes. That is, one of the main image and the background image is printed by the forward path operation and the backward path operation. The lower layer image to be printed first of the main image and the background image is printed at least in the forward pass operation, and the upper layer image to be printed later is printed at least in the backward pass operation. For example, as shown in FIG. 11, when a background image is printed in two passes in the surface printing mode, the background image is printed by the forward operation and the backward operation, and the main image is printed by the backward operation. In this case, the time from the pass for printing the background image as the lower layer image to the pass for printing the main image as the upper layer image for the predetermined area of the medium, that is, the drying time of the lower layer image is the time required for the transport operation. This is the total time required for the forward movement. Therefore, the drying time of the lower layer image can be made longer in Example 3 than in the comparative example shown in FIG. As a result, it is possible to suppress bleeding and color mixing of the print image and to suppress deterioration in the image quality of the print image.

  Although not shown, when the main image is printed in two passes in the front printing mode, the background image is printed by the forward operation, and the main image is printed by the forward operation and the backward operation. When printing the background image in two passes in the reverse printing mode, the main image is printed in the forward pass operation, the background image is printed in the forward pass operation and the backward pass operation, and the main image is printed in the reverse pass mode in two passes. In the case of printing with the forward operation, the main image is printed by the forward operation and the backward operation, and the background image is printed by the backward operation. Even in these cases, the time from the pass for printing the lower layer image to the pass for printing the upper layer image on the predetermined area of the medium is the total time of the time required for the transport operation and the time required for the forward operation or the backward operation. Become. Therefore, in Example 3, the drying time of the lower layer image can be made longer than that in the comparative example.

  In addition, when printing one image of the main image and the background image in two passes, it is possible to overlap the dots for the forward movement and the dots for the backward movement. As a result, the amount of ink constituting the image can be increased in the third embodiment compared to the first embodiment (FIG. 7) and the second embodiment (FIG. 9). For example, when the background image is printed in two passes, the background image can be shielded, and when the main image is printed in two passes, the main image can be colored. it can.

  Further, not only when the dots are overlapped, but when one of the main image and the background image is printed in two passes, the dot formation position in the forward operation and the dot formation position in the backward operation are different. Can be made. For example, when the background image is printed by band printing in one pass as in the first embodiment shown in FIG. 7, the nozzles for the background image form dots arranged in the moving direction in one pass. There must be. On the other hand, when the background image is printed by band printing in two passes as in the third embodiment of FIG. 11, each nozzle for the background image alternately has dots arranged in the moving direction in the forward operation and the backward operation. In other words, dots arranged in the moving direction can be formed by different passes. As a result, it is possible to suppress blurring and color mixing of dots arranged in the moving direction, and it is possible to suppress deterioration in image quality of the printed image.

  Furthermore, when printing an image in two passes, the nozzles arranged in the transport direction in the nozzle row can be alternately used in the forward path operation and the backward path operation. For example, even-numbered nozzles are used in the forward operation, and odd-numbered nozzles are used in the backward operation. For example, in the case of FIG. 11, among the background image nozzles (# 6 to # 10), even-numbered nozzles # 6, # 8, and # 10 are used in the forward operation, and odd-numbered nozzles # are used in the backward operation. 7, # 9 may be used. As a result, dots arranged in the transport direction can be printed in different passes, and bleeding and color mixing of dots arranged in the transport direction can be suppressed.

  In addition, when printing the lower layer image in two passes, the image portion (dot) printed in the forward pass (previous pass) is better than the image portion (dot) printed in the return pass (subsequent pass). , Drying time becomes longer. Therefore, when the lower layer image is printed in two passes, the image portion printed in the forward pass operation is preferably made larger than the image portion printed in the return pass operation. Conversely, when the upper layer image is printed in two passes, the lower layer image portion that overlaps the upper layer image portion that is printed in the backward pass operation (subsequent pass) is the upper layer image portion that is printed in the forward pass operation (previous pass). The drying time is longer than the lower layer image portion that overlaps with. Therefore, when the upper layer image is printed in two passes, it is preferable to make the image portion printed in the backward operation larger than the image portion printed in the forward operation. For example, as shown in FIG. 11, when a background image that is a lower layer image is printed in two passes, two out of three dots arranged in the movement direction are formed in the forward movement, and movement is performed in the backward movement. One of the three dots arranged in the direction may be formed. In addition, the number of nozzles (# 6, # 8, # 10) for printing the background image in the forward pass operation may be larger than the number of nozzles (# 7, # 9) for printing in the backward pass operation. By doing so, the drying time of more parts of the lower layer image can be lengthened, and bleeding and color mixing of the image can be suppressed.

As described above, in the present embodiment, when the white use mode is performed, the nozzle for an image that is printed first with respect to a predetermined area of the medium out of the main image and the background image is more than the nozzle for an image that is printed later. An image is printed by a first printing method in which a forward operation, a backward operation, and a transportation operation are sequentially repeated, and each image is printed by at least one of the forward operation and the backward operation. The printer driver creates or rearranges print data. Therefore, the controller 10 of the printer 1 and the computer 60 on which the printer driver is installed correspond to the control unit, and the printing system in which the printer 1 and the controller 10 are connected corresponds to the fluid ejecting apparatus.
However, the present invention is not limited to this, and the controller 10 of the printer 1 may play the role of a printer driver. In this case, the controller 10 of the printer 1 corresponds to the control unit, and the printer 1 alone corresponds to the fluid ejecting apparatus.

=== Modification ===
In the flow of FIG. 6 described above, when the white usage mode is selected, the printing method is always set to the first printing method, but the present invention is not limited to this. When the white use mode is selected, the first printing method may be set as a recommended printing method (as a default). Even in the white usage mode, the user may be able to select the second printing method on the setting screen or the like. Since the second printing method can shorten the printing time than the first printing method, the second printing method can be implemented even in the white usage mode when the user wants to print faster (for example, in trial printing). It may be.

In the above-described embodiment, the background image in which the white color is adjusted using the white ink and the four colors of ink is described as an example, but the present invention is not limited to this. It may be a background image printed using only white ink.
In the above-described embodiment, the main image is printed using only four colors of ink (YMCK). However, the present invention is not limited to this. For example, the main image may be printed using white ink together with four color inks. By printing the main image by adding the white ink to the four colors of ink, it is possible to print an image that reproduces a color with high brightness and high saturation. In this case, in the front printing / white use mode printing shown in FIG. 7 described above, the main image is printed using the nozzle group (# 1 to # 5) on the downstream side in the transport direction of the white nozzle row W.
In the above-described embodiment, the background image is printed with the white ink. However, the present invention is not limited to this, and the background image may be printed with a color ink other than white (for example, metallic ink).

  In the third modification described above, one of the main image and the background image is printed in two passes (the forward pass operation and the return pass operation). However, the present invention is not limited to this. Both the main image and the background image may be printed in two passes. In this case, the time from the pass for printing the lower layer image of the main image and the background image to the pass for printing the upper layer image is the time required for the transport operation as in the comparative example. However, if the dots for the forward operation and the dots for the backward operation are not overlapped, the amount of ink ejected in one pass is smaller than that in the comparative example, and dots arranged in the movement direction and the transport direction are formed in different passes. . Therefore, even if the drying time of the lower layer image is about the same as that of the comparative example, the present embodiment in which the first printing method is performed is more blurred and mixed in the printed image than the comparative example in which the second printing method is performed. Can be suppressed.

=== Other Embodiments ===
Each of the above embodiments is described mainly for a printing system having an ink jet printer, but includes disclosure of a printing method and the like. The above-described embodiments are for facilitating 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 ink and recording medium>
In this embodiment, ink and an ink-absorbing medium (ink-absorbing recording medium) that absorbs the ink are used. As the ink absorptive recording medium, a recording medium composed of a substrate having ink absorptivity or a recording medium provided with an ink receiving layer on the substrate can be used. Examples of the substrate having ink absorptivity include paper and cloth. The ink may be any ink that is absorbed by the absorbent medium, but preferably contains an evaporable solvent in order to ensure absorbability to the ink absorbent medium. Further, “water-based ink” containing at least water as a solvent is particularly preferable. As other components constituting the ink, there are dyes and pigments as color materials. In addition, it may contain a water-soluble organic solvent for ejection stability from an inkjet head, and if necessary, contains a moisturizing agent, a penetration enhancer, a ph regulator, an insect repellent, an ultraviolet absorber and the like. It may be. As such a color ink, for example, inks described in JP-A-2008-81693, JP-A-2005-105135, and JP-A-2003-292934 can be used.

  The recording medium fixes the color material of the ink composition by absorbing the solvent of the ink composition. For example, a medium using a base material that absorbs ink such as paper or cloth may be used, or a base material that absorbs ink or a base material that does not absorb ink may be provided with an ink receiving layer that absorbs ink. When a transparent medium is used, for example, recording media described in JP-A-2009-925, JP-A-9-99634, and JP-A-9-208870 can be used.

  As the ink receiving layer, a known ink receiving layer usually provided on a recording medium for an ink jet recording method can be used. As the known ink receiving layer, for example, an ink receiving layer made of a resin is known. Examples of the resin used for the ink receiving layer include, for example, Japanese Patent Application Laid-Open Nos. 57-38185 and 62-184879. Polyvinyl pyrrolidone or vinyl pyrrolidone-vinyl acetate copolymer as disclosed in JP-A Nos. 60-168651, 60-171143, and 61-134290. Resin composition mainly, copolymer of vinyl alcohol and olefin or styrene and maleic anhydride as disclosed in JP-A-60-234879, disclosed in JP-A-61-74879 A cross-linked product of polyethylene oxide and isocyanate, as described in JP-A-61-1181679 A mixture of carboxymethyl cellulose and polyethylene oxide as shown, a polymer obtained by grafting methacrylamide to polyvinyl alcohol as disclosed in JP-A-61-2132377, JP-A-62-220383 An acrylic polymer having a carboxyl group as disclosed, a polyvinyl acetal polymer as disclosed in JP-A-4-214382, etc., and JP-A-4-282282 and 4-285650. And various ink-absorbing polymers such as crosslinkable acrylic polymers.

  As known ink receiving layers, JP-A-4-282282, 4-285650, etc. disclose an ink receiving layer using a polymer matrix composed of a crosslinkable polymer and an absorbent polymer in combination. Yes. Further, an ink receiving layer using alumina hydrate (cationic alumina hydrate) is also known, for example, JP-A-60-232990, JP-A-60-245588, and JP-B-3-24906. JP-A-6-199035 and JP-A-7-82694 disclose a recording medium in which fine pseudo boehmite type alumina hydrate is coated on a substrate surface together with a water-soluble binder. For example, Japanese Patent Application Laid-Open No. 10-203006 discloses an ink receiving layer using a synthetic silica mainly having a primary particle diameter of 3 nm to 30 nm by a vapor phase method. Furthermore, Japanese Patent Application Laid-Open No. 2001-328344 discloses an ink receiving layer containing an inorganic pigment and a polymer adhesive. In the present invention, it is preferable to use a film substrate provided with each of these ink receiving layers.

  In the method of the present invention, any white ink composition usually used in the ink jet recording method can be used as the white ink composition for the background image. Examples of such white pigments include inorganic white pigments, organic white pigments, and white hollow polymer fine particles. As the white ink composition, a water-based ink composition containing hollow polymer fine particles as a colorant component. Is preferably used.

  Examples of inorganic white pigments include alkaline earth metal sulfates such as barium sulfate, alkaline earth metal carbonates such as calcium carbonate, silicas such as finely divided silicic acid and synthetic silicates, calcium silicate, alumina, alumina Hydrates, titanium oxide, zinc oxide, talc, clay and the like can be mentioned. In particular, titanium oxide is known as a white pigment having preferable hiding properties, coloring properties, and dispersed particle sizes.

  Examples of the organic white pigment include organic compound salts disclosed in JP-A No. 11-129613 and alkylene bismelamine derivatives disclosed in JP-A Nos. 11-14365 and 2001-234093. Specific examples of the white pigment include Shigenox OWP, Shigenox OWPL, Shigenox FWP, Shigenox FWG, Shigenox UL, and Shigenox U (all trade names manufactured by Hackol Chemical Co., Ltd.).

  The hollow polymer fine particles contained as the colorant component can be fine particles having an outer diameter of about 0.1 to 1 μm and an inner diameter of about 0.05 to 0.8 μm, and are insoluble in the solvent of the white ink composition. Thus, it is necessary that the component does not chemically react with other components, for example, a binder resin component. The hollow polymer fine particles are made of a synthetic polymer whose walls are permeable to liquid, and the space at the center of the hollow polymer fine particles can pass through the walls and allow liquid to enter and exit. Therefore, the space in the center of the hollow polymer fine particles is filled with the solvent in the state of the ink composition, and the specific gravity of the hollow polymer fine particles and the specific gravity of the ink composition are substantially the same. It is stably dispersed inside. On the other hand, when the ink composition is printed on the printing surface and dried, the space at the center of the hollow polymer fine particles is replaced with air, so that incident light is diffusely reflected between the resin and the space, and substantially white.

  Further, as described above, the hollow polymer fine particle contains a liquid in the fine particle before printing, but the liquid that has entered the fine particle passes through the fine particle wall after printing and diffuses. It can be of a type in which fine pores are filled with air or a completely sealed type in which air is initially contained inside. Since it is desired that the hollow polymer fine particles used in the white ink composition do not precipitate in the ink composition, those having a specific gravity approximately equal to the specific gravity of the ink composition solution are preferable. For this reason, it is preferable to adjust the specific gravity of the ink composition solution using a specific gravity adjusting agent such as glycerol as necessary.

  Examples of commercially available hollow polymer fine particles satisfying the above properties include Ropaque OP-62 commercially available from Rohm and Haas. This is an aqueous dispersion containing 38% by weight of hollow polymer fine particles made of an acrylic / styrene copolymer. The inner diameter of the fine particles is about 0.3 μm, the outer diameter is about 0.5 μm, and the inside is filled with water.

  The hollow polymer fine particles can also be obtained by a known production method, for example, the method disclosed in US Pat. No. 4,089,800. The hollow polymer fine particles are substantially made of an organic polymer and exhibit mature plasticity. The thermoplastic resin used for the production of the hollow polymer fine particles is preferably a cellulose derivative, acrylic resin, polyolefin, polyamide, polycarbonate, polystyrene, styrene or other vinyl monomer copolymer, vinyl acetate, vinyl alcohol. And vinyl polymers such as vinyl chloride or vinyl butyral homopolymers or copolymers, diene homopolymers and copolymers, and the like. Particularly preferred thermoplastic polymers include copolymers of 2-hexyl acrylate, copolymers of methyl methacrylate, and copolymers of styrene and other vinyl monomers such as acrylonitrile. be able to.

  The content of the hollow polymer fine particles in the white ink composition used in the present invention can be, for example, 0.1 to 20% by weight. When the content of the hollow polymer fine particles is 0.1% by weight or more, sufficient whiteness can be obtained. On the other hand, if it is 20% by weight or less, a sufficient amount of the ink binder resin component necessary for ensuring the viscosity required for the ink composition for ink jet printing can be contained, and as a result, sufficient printing adhesion can be achieved. Sex can be secured.

  In the present invention, the white pigment may be used alone or in combination. For the dispersion of the pigment, a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, a paint shaker, or the like can be used. It is also possible to add a dispersant when dispersing the pigment.

  The white ink composition used in the present invention contains, in addition to the white colorant component, various components usually contained in an ink composition for inkjet printing, such as a resin component, a dispersant component, a solvent component (especially water), and the like. Can be contained. In the present specification, the term “solvent” and “solvent” are used interchangeably. Moreover, as a white ink composition containing hollow polymer fine particles as a white colorant, for example, the composition described in Japanese Patent No. 3562754 (Patent Document 1) or Japanese Patent No. 3639479 (Patent Document 2) is used. You can also.

  The non-white ink composition for color images used in the present invention is, for example, a color ink composition, a black ink composition, or a gray ink composition. Examples of the color ink composition include a cyan ink composition, a magenta ink composition, a yellow ink composition, a light cyan ink composition, a light magenta ink composition, and a red ink composition and a green ink composition. Or a blue ink composition. As the non-white ink composition, the various ink compositions described above can be used alone or in combination of two or more.

  As the non-white ink composition, any non-white ink composition usually used in the ink jet recording method can be used, and a water-based ink composition containing a dye or a pigment as a colorant component is preferably used. In particular, it is preferable to use an ink composition that exhibits good characteristics (for example, color developability and fixability) with respect to the transparent film substrate or the ink receiving layer.

  If the ink and recording medium used in the present invention are as described above, the ink drying time can be increased by providing a long time interval between the previous image formation and the subsequent image formation as in the above-described embodiment. Image blur and color mixing can be prevented. However, the ink and recording medium used in the present invention are not limited to those described above. Any time period may be used as long as the time interval between the previous image formation and the subsequent image formation is set so that the components in the ink adhere to the recording medium. In other words, other inks or recording media may be used as long as the time interval between the previous image formation and the subsequent image formation is set longer to prevent image bleeding and color mixing.

<About the printer>
In the above-described embodiment, the printer 1 that repeats the operation of forming an image on a sheet of paper while moving the head 41 in the movement direction and the operation of conveying the sheet of paper in the conveyance direction with respect to the head is taken as an example. However, it is not limited to this. For example, an operation of forming an image while moving a head unit 40 having a plurality of heads 41 in the medium conveyance direction and an operation of moving the head unit 40 in the paper width direction with respect to continuous paper conveyed to the printing area And a printer that forms an image by repeating the above and then conveys a medium portion that has not yet been printed to the printing area.

<About fluid ejection device>
In the above-described embodiment, an ink jet printer is exemplified as the fluid ejecting apparatus, but the present invention is not limited thereto. If it is a fluid ejecting apparatus, it can be applied to various industrial apparatuses, not a printer (printing apparatus). For example, a textile printing apparatus for applying a pattern to a fabric, a display manufacturing apparatus such as a color filter manufacturing apparatus or an organic EL display, a DNA chip manufacturing apparatus for manufacturing a DNA chip by applying a solution in which DNA is dissolved to a chip, and the like. Also, the present invention can be applied.
Further, the fluid ejection method from the nozzle may be a piezo method in which a fluid is ejected by applying a voltage to the driving element (piezo element) to expand and contract the pressure chamber, or bubbles are generated in the nozzle using a heating element. A thermal method may be used in which the liquid is generated and the liquid is ejected by the bubbles.

1 Printer, 10 Controller, 11 Interface section,
12 CPU, 13 memory, 14 unit control circuit,
20 transport unit, 30 carriage unit, 31 carriage,
40 head units, 41 heads, 50 detector groups,
60 computers

Claims (6)

(A) a first nozzle row in which nozzles that eject the first fluid are arranged in a predetermined direction;
(B) a second nozzle row in which nozzles for ejecting a second fluid are arranged in the predetermined direction and arranged in the moving direction that is a direction intersecting the predetermined direction;
(C) When the formation of the main image by the first fluid and the formation of the background image by the second fluid are performed on a medium,
A forward movement operation for relatively moving the first nozzle row, the second nozzle row, and the medium in one direction of the movement direction, and the movement direction of the first nozzle row, the second nozzle row, and the medium. The return path operation for moving the relative direction in the other direction of the first and the transport operation for moving the relative position of the medium to the one side in the predetermined direction with respect to the first nozzle row and the second nozzle row are the forward path operation and the return path By repeating the operation and the conveying operation in this order, an image is formed on the medium,
One of the nozzle groups of the first nozzle array that forms the main image and one of the nozzle groups of the second nozzle array that forms the background image, and the other nozzle group Also using the one nozzle group located on the other side of the predetermined direction, an image is formed on a predetermined area of the medium before the other nozzle group,
In order to form the main image, a fluid is ejected from the nozzle during at least one of the forward operation and the backward operation,
A controller that ejects fluid from the nozzle during at least one of the forward operation and the backward operation for forming the background image;
A fluid ejecting apparatus comprising (D). The fluid ejection device according to claim 1,
The one nozzle group that performs image formation on a predetermined region of the medium first ejects fluid at least during the forward operation.
Fluid ejection device. The fluid ejecting apparatus according to claim 1 or 2,
The other nozzle group that forms an image later on a predetermined area of the medium ejects fluid at least during the return path operation.
Fluid ejection device. The fluid ejecting apparatus according to any one of claims 1 to 3,
At least one of the time required for one forward operation and the time required for one return operation is longer than the time required for one transport operation;
Fluid ejection device. The fluid ejection device according to any one of claims 1 to 4,
The background image is formed using the nozzles of the first nozzle row whose position in the predetermined direction is the same as a part of the nozzle group of the second nozzle row that forms the background image.
Fluid ejection device. The first nozzle row in which the nozzles for ejecting the first fluid are arranged in a predetermined direction, and the nozzles for injecting the second fluid are arranged in the predetermined direction, and the moving direction is a direction intersecting the predetermined direction. A fluid ejecting method for a fluid ejecting apparatus having a second nozzle array aligned with one nozzle array,
When the formation of the main image by the first fluid and the formation of the background image by the second fluid are performed on a medium,
A forward movement operation for relatively moving the first nozzle row, the second nozzle row, and the medium in one direction of the movement direction, and the movement direction of the first nozzle row, the second nozzle row, and the medium. The return path operation for moving the relative direction in the other direction of the first and the transport operation for moving the relative position of the medium to the one side in the predetermined direction with respect to the first nozzle row and the second nozzle row are the forward path operation and the return path An image is formed on the medium by repeating the operation and the transport operation in this order,
One of the nozzle groups of the first nozzle array that forms the main image and one of the nozzle groups of the second nozzle array that forms the background image, and the other nozzle group And using the one nozzle group located on the other side of the predetermined direction to form an image on a predetermined area of the medium before the other nozzle group,
In order to form the main image, a fluid is ejected from the nozzle during at least one of the forward operation and the backward operation,
In order to form the background image, a fluid is ejected from the nozzle during at least one of the forward operation and the backward operation.
And a fluid ejection method.

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