JP2010221718A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer which can more quickly print an image so that stripes generated by color unevenness etc. are unnoticeable. <P>SOLUTION: The printer prints the image by forming dots by delivering an ink to a medium conveyed in a conveying direction from nozzles while a plurality of the nozzles move in an intersecting direction that intersects the conveying direction. The printer has a first print mode for printing a mirror image of a predetermined image as the image to a transparent medium as the medium, and a second print mode for printing a normal image of the predetermined image as the image to the medium. At least either of the conveying operation of conveying the medium and the dot forming operation of forming dots by delivering the ink while moving the nozzles is different from each other between the first print mode and the second print mode. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a printing apparatus.

  As a printing apparatus that prints an image on a medium, an image is formed by ejecting ink from the nozzles to form dots by moving a plurality of nozzles in a crossing direction intersecting the transporting direction on a medium transported in the transporting direction. Inkjet printers for printing are known (see, for example, Patent Document 1). The ink jet printer forms an image by forming a plurality of dot rows in which dots formed by ink ejected from the nozzles are arranged in the intersecting direction by moving in the intersecting direction of the nozzles and arranged in the transport direction by transporting the medium. .

Japanese Patent Laid-Open No. 10-323978

Ink jet printers may cause stripes along the crossing direction due to color unevenness or the like in the formed image due to differences in the characteristics of ejecting ink from each nozzle, or differences in dot rows formed by the movement of different nozzles. There is. Such stripes are likely to occur in a printing mode in which an image is printed at a high speed, and there is a problem that the fringes appear more prominently when the surface of the formed image is rough.
Accordingly, an object of the present invention is to provide a printing apparatus capable of printing an image more quickly so that stripes caused by color unevenness and the like are not noticeable.

The main invention for achieving the above object is:
A printing apparatus that prints an image on a medium transported in a transport direction by ejecting ink from the nozzles while forming a dot while moving in a crossing direction intersecting the transport direction.
A first print mode for printing a mirror image of a predetermined image on the transparent medium as the medium as the image; and a second print mode for printing a normal image of the predetermined image on the medium as the image. ,
The first print mode and the second print mode include at least one of a transport operation for transporting the medium and a dot formation operation for ejecting ink while moving the nozzle to form dots. The printing apparatus is characterized by being different from each other.

  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 illustrating a configuration of a printing system and a printer. FIG. 2 is a schematic view around a printer head. It is AA sectional drawing of FIG. It is explanatory drawing of a structure of a head. It is a figure for demonstrating the conveyance operation | movement and dot formation operation | movement in band printing mode. It is a figure for demonstrating the conveyance operation | movement and dot formation operation | movement in pseudo band printing mode. It is a figure for demonstrating the conveyance operation | movement and dot formation operation | movement in interlaced printing mode. It is a figure for demonstrating the conveyance operation | movement and dot formation operation | movement in the band printing mode of an overlap system. It is a figure for demonstrating the conveyance operation | movement and dot formation operation | movement in the overlap type pseudo | simulation band printing mode. FIG. 5 is a diagram for explaining a transport operation and a dot formation operation in an overlap type interlaced printing mode. It is a figure for demonstrating an example of the process at the time of printing on a transparent medium with a printer. It is a figure for demonstrating a conveyance operation | movement and dot formation operation | movement in the interlaced printing mode of the overlap system performed as surface printing mode, and a mode that a dot is formed. It is a figure for demonstrating a conveyance operation | movement and dot formation operation | movement in a non-overlapping interlaced printing mode performed as back printing mode, and a mode that a dot is formed. It is a figure for demonstrating a conveyance operation | movement and dot formation operation | movement in a non-overlapping interlaced printing mode performed as surface printing mode, and a mode that a dot is formed. It is a figure for demonstrating a conveyance operation | movement and dot formation operation | movement in the band printing mode performed as back | printing | printing_printing mode, and a dot formation. It is a figure for demonstrating the modification of the process at the time of printing on a transparent medium with a printer.

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

  A printing apparatus that prints an image on a medium transported in a transport direction by ejecting ink from the nozzles while forming a dot while moving in a crossing direction intersecting the transport direction. A first print mode for printing a mirror image of a predetermined image as the image on a transparent medium as a medium, and a second print mode for printing a normal image of the predetermined image as the image on the medium; The first print mode and the second print mode include at least one of a transport operation for transporting the medium and a dot formation operation for ejecting ink while moving the nozzle to form dots. The printing apparatus is characterized by being different from each other.

  According to such a printing apparatus, among the first printing mode for printing a mirror image on a transparent medium and the second printing mode for printing a normal image on a medium, among the conveying operation and the dot forming operation. Since at least one of the above is different from each other, it is possible to print with a suitable transport operation and dot formation operation for printing a mirror image on a transparent medium and printing a normal image on a medium. It is. For this reason, both in the case of printing a mirror image on a transparent medium and in the case of printing a normal image on a medium, it is possible to print an image faster because the stripes caused by color unevenness are conspicuous.

Here, the fact that at least one of the transport operation and the dot formation operation is different between the first print mode and the second print mode means that the same image is displayed in the first print mode and the second print mode. When printing at, a transport operation with a different transport amount or transport timing of the medium is executed, or a dot formation operation with a different nozzle moving direction or ink discharge timing or the like when discharging ink is executed. Which indicates that. For this reason, since the images to be printed are different, it does not include that the positions on the medium where ink is ejected and dots are formed are different.
In addition, the transparent medium includes not only a completely colorless and transparent medium but also a film having high translucency such that an image can be seen through the medium.

In this printing apparatus, the dot forming operation in the second printing mode is the number of times the nozzle is moved to form one dot row that constitutes the image and in which the dots are arranged in the intersecting direction. However, it is desirable that there are more dot formation operations than in the first print mode.
When an image printed on a medium such as paper is viewed from the printing surface, the uneven density of the stripes tends to be noticeable because of irregular reflection, but when the image printed on a transparent film is viewed through the transparent film, the surface is Since the film has a film surface and the surface has a high degree of smoothness, it does not diffusely reflect, and stripe density unevenness is not noticeable. For this reason, in the dot formation operation in the second print mode, the number of times of moving the nozzles to form one dot row arranged in the intersecting direction is increased compared to the dot formation operation in the first print mode. In the second printing mode, it is possible to print an image in which density unevenness is less noticeable. In addition, the density unevenness of the image printed in the first print mode is easily noticeable when viewed directly, but the density unevenness is less noticeable when the printed image is viewed as a normal image through the transparent medium. For this reason, when printing a mirror image and printing an image for viewing through a transparent medium, the image can be printed faster by reducing the number of times the nozzle is moved to form one dot row. Is possible.

In this printing apparatus, an interval in the transport direction of the plurality of dot rows that configure the image and in which the dots are arranged in the intersecting direction is set to the second print mode from the transport operation in the first print mode. The medium may be transported so that the transport operation becomes narrower.
According to such a printing apparatus, an image printed in the second printing mode in which a normal image is printed is printed with a narrow interval between dot rows in the transport direction, so that an image with less uneven density is printed. Is possible.

In this printing apparatus, the dot forming operation in the second printing mode is configured to eject ink when moving the nozzle in a predetermined direction through a dot row that constitutes the image and in which the dots are arranged in the intersecting direction. The dot forming operation in the first printing mode may be formed by ejecting ink when the dot row is moved in a predetermined direction of the nozzle and in a direction opposite to the predetermined direction.
According to such a printing apparatus, in the image printed in the second printing mode, since the movement direction of the nozzle when ejecting ink to form a dot row is the same, the positional accuracy at which dots are formed is high. It is possible to print a better image, and the image printed in the first printing mode is printed because the moving direction of the nozzles when the ink is ejected in order to form a dot row is alternated. By viewing the printed image through a transparent medium, it is possible to print an image in which uneven density is less noticeable.

In this printing apparatus, the dot forming operation in the second printing mode and the dot forming operation in the first printing mode are one dot that constitutes the image and in which the dots are arranged in the intersecting direction. Each of the columns is formed by ejecting ink from a plurality of nozzles different from each other, and the number of nozzles that eject ink to form the one dot row is greater in the second printing mode. It may be more than one print mode.
According to such a printing apparatus, in the dot formation operation in the second print mode, the number of nozzles that eject ink to form a dot row in which dots are arranged in the intersecting direction is set to the dot in the first print mode. By increasing the number of forming operations, it is possible to form an image in which density unevenness is less noticeable in the second printing mode. Further, when the image in the first printing mode is viewed directly, the density unevenness is easily noticeable, but since the mirror image is printed, the density unevenness is less noticeable by viewing the image through the transparent medium. For this reason, when printing an image for printing a mirror image and seeing it through a transparent medium, it is possible to print the image faster by reducing the number of nozzles forming one dot row.

In such a printing apparatus, in the dot forming operation in the first printing mode, it is preferable that ink is ejected from a single nozzle in order to form the one dot row.
According to such a printing apparatus, since one dot row constituting an image printed in the first printing mode in which density unevenness is less noticeable when viewed through the medium is formed by a single nozzle, It is possible to print an image faster.

In this printing apparatus, it is preferable that at least one of the first printing mode and the second printing mode prints a background image that is a background of the printed image.
According to such a printing apparatus, when printing is performed in at least one of the first printing mode and the second printing mode, since the image is printed on the background image, the printing is performed on the transparent medium. Even if the image is a transparent image, there is no transparent area in the print area where the image and the background image are printed. For this reason, since an object existing on the other side of the medium is not seen from the transparent portion in the image area, it is possible to print an image that looks clearer.

  A printing apparatus that prints an image on a medium transported in a transport direction by ejecting ink from the nozzles and forming dots while moving in a crossing direction intersecting the transport direction. A first print mode for printing the image for viewing through the transparent medium on the transparent medium as the medium, and a second print mode for printing the image for direct viewing, In the first printing mode and the second printing mode, at least one of a conveying operation for conveying the medium and a dot forming operation for forming dots by ejecting ink while moving the nozzles is mutually It is a printing apparatus characterized by being different.

  According to such a printing apparatus, the conveyance is performed in the first print mode for printing an image for viewing through the transparent medium on the transparent medium and in the second print mode for printing an image for direct viewing. Since at least one of the operation and the dot forming operation is different from each other, conveyance suitable for printing an image for viewing through a transparent medium and for printing an image for direct viewing, respectively. It is possible to print by operation and dot formation operation. For this reason, when printing a mirror image on a transparent medium and when printing a normal image on a medium, it is possible to print an image faster so that stripes caused by color unevenness and the like are not noticeable.

  Here, the fact that at least one of the transport operation and the dot formation operation is different between the first print mode and the second print mode means that the same image is displayed in the first print mode and the second print mode. When printing at, a transport operation with a different transport amount or transport timing of the medium is executed, or a dot formation operation with a different nozzle moving direction or ink discharge timing or the like when discharging ink is executed. Which indicates that. For this reason, since the images to be printed are different, it does not include that the positions on the medium where ink is ejected and dots are formed are different.

  Also, the image for direct viewing and the image for viewing through a transparent medium differ depending on the selection of the user who performed the printing operation, printer settings, and the like. For example, the image cannot be seen through the medium. For example, the selected medium is not transparent, or the background image is printed on the transparent medium before the image. The image to be viewed through the transparent medium is an image in which the transparent medium is selected as the medium and the background image is printed on the image printed on the transparent medium.

  In the following embodiments, a printing system having an inkjet printer (hereinafter also referred to as a printer) as a printing apparatus and a computer that is communicably connected to the printer will be described as an example.

=== Embodiment ===
Hereinafter, the printing system 100 and the printer 1 according to the present embodiment will be described with reference to FIGS. 1, 2, and 3. FIG. 1 is a block diagram illustrating configurations of a printing system and a printer. FIG. 2 is a schematic view around the head of the printer. FIG. 3 is a cross-sectional view taken along the line AA of FIG.

  As illustrated in FIG. 1, the printing system 100 includes a printer 1 and a computer 80 connected to the printer 1 so as to be communicable. The computer 80 connected to the printer 1 so as to be communicable has an operation unit (not shown) for operation by a user or the like, and image data to be printed based on information input from the operation unit by the user or the like. Is installed on the printer 1 to print data that can be printed by the printer 1. Image data for printing a mirror image by the printer 1 is also generated by processing of the printer driver.

<About printer configuration>
The printer 1 of the present embodiment ejects ultraviolet curable ink (hereinafter referred to as UV ink) that is cured by irradiation with ultraviolet light (hereinafter referred to as UV) as an example of ink toward a medium such as paper, cloth, or film sheet. Thus, the color ink jet printer is capable of printing an image on a medium. Here, the medium includes a transparent medium such as a transparent film sheet.

  When printing on a transparent medium, the printer 1 can print both an image for directly viewing the printed image from the printed side of the transparent medium and an image for viewing through the transparent medium. It is. At this time, the image for directly viewing the image is a normal image of an original predetermined image, such as an image read by a scanner or an image taken by a digital camera, and the image for viewing through a transparent medium is In many cases, it is a mirror image of the original predetermined image. However, the present invention is not limited to this in the case where a left-right symmetrical image or an image obtained by inverting the left and right with respect to the original image is printed.

  The UV ink is an ink containing an ultraviolet curable resin, and is cured by a photopolymerization reaction occurring in the ultraviolet curable resin when irradiated with UV. Note that the printer 1 of the present embodiment prints using four colors of CMYK and white (W) UV ink in order to print a background image.

  The printer 1 includes a transport unit 10, a carriage unit 20, a head unit 30, an irradiation unit 40, a detector group 50, and a controller 60. The printer 1 that has received the print data from the computer 80 that is an external device controls each unit (the transport unit 10, the carriage unit 20, the head unit 30, and the irradiation unit 40) by the controller 60. The controller 60 controls each unit based on the print data received from the computer 80 and prints an image on a medium. The situation in the printer 1 is monitored by the detector group 50, and the detector group 50 outputs the detection result to the controller 60. The controller 60 controls each unit based on the detection result output from the detector group 50.

  The transport unit 10 is for transporting a medium in a predetermined direction (hereinafter referred to as a transport direction). The transport unit 10 includes a paper feed roller 11, a transport motor (not shown), a transport roller 13, a platen 14, and a paper discharge roller 15. The paper feed roller 11 is a roller for feeding the medium inserted into the paper insertion slot into the printer 1. The transport roller 13 is a roller that transports the medium fed by the paper feed roller 11 to a printable region (printable region), and is driven by a transport motor. The platen 14 supports the medium being printed. The paper discharge roller 15 is a roller for discharging the medium to the outside of the printer, and is provided on the downstream side in the transport direction with respect to the printable area.

  The carriage unit 20 is for moving (also referred to as “scanning”) the head in an intersecting direction (also referred to as a moving direction) that intersects the transport direction. The carriage unit 20 includes a carriage 21 and a carriage motor (not shown). The carriage 21 detachably holds an ink cartridge that stores UV ink. The carriage 21 is reciprocated along the guide shaft 24 by a carriage motor while being supported by a guide shaft 24 that intersects a conveyance direction described later.

The head unit 30 is for ejecting ink (in this embodiment, UV ink) onto a medium. The head unit 30 includes a head 31 having a plurality of nozzles. Since the head 31 is provided on the carriage 21, when the carriage 21 moves in the movement direction, the head 31 also moves in the movement direction. Then, when the head 31 is intermittently ejected while moving in the moving direction, a raster line as a dot row along the moving direction is formed on the medium. Hereinafter, in the movement of the head 31, the movement from one end side to the other end side in FIG. 2 is called forward movement, and the movement from the other end side to one end side is called backward movement.
The configuration of the head 31 will be described later.

  The irradiation unit 40 irradiates UV toward the UV ink that has landed on the medium. The dots formed on the medium are cured by receiving UV irradiation from the irradiation unit 40. The irradiation unit 40 of the present embodiment includes provisional curing irradiation units 41 a and 41 b and a main curing irradiation unit 43. The details of the pre-curing irradiation units 41a and 41b and the main curing irradiation unit 43 will be described later.

  The detector group 50 includes a linear encoder (not shown), a rotary encoder (not shown), a paper detection sensor 53, an optical sensor 54, and the like. The linear encoder detects the position of the carriage 21 in the moving direction. The rotary encoder detects the rotation amount of the transport roller 13. The paper detection sensor 53 detects the position of the leading edge of the medium being fed. The optical sensor 54 detects the presence or absence of a medium by a light emitting unit and a light receiving unit attached to the carriage 21. The optical sensor 54 can detect the position of the end of the medium while being moved by the carriage 21 to detect the width of the medium. In addition, the optical sensor 54 has a leading end (an end on the downstream side in the transport direction, also referred to as an upper end) and a rear end (an end on the upstream side in the transport direction, also referred to as a lower end), depending on the situation, Whether the medium is transparent or not can also be detected.

  The controller 60 is a control unit (control unit) for controlling the printer 1. The controller 60 includes an interface unit 61, a CPU 62, a memory 63, and a unit control circuit 64. The interface unit 61 transmits and receives data between the computer 80 which is an external device and the printer 1. The CPU 62 is an arithmetic processing unit for controlling the entire printer 1. The memory 63 is for securing an area for storing a program of the CPU 62, a work area, and the like, and includes storage elements such as a RAM and an EEPROM. The CPU 62 controls each unit via the unit control circuit 64 in accordance with a program stored in the memory 63.

  When performing printing, the controller 60 alternately repeats a dot formation operation for ejecting UV ink from the head 31 moving in the movement direction and a conveyance operation for conveying paper in the conveyance direction, as will be described later. An image composed of the above is printed on paper. Hereinafter, the dot forming operation is referred to as “pass”. The n-th pass is called a pass n.

<About the configuration of the head 31>
FIG. 4 is an explanatory diagram of an example of the configuration of the head 31. On the lower surface of the head 31, as shown in FIG. 4, there are a black ink nozzle row K, a cyan ink nozzle row C, a magenta ink nozzle row M, a yellow ink nozzle row Y, and two white ink nozzle rows W. Is provided. As shown in FIG. 4, these nozzle rows are arranged with white ink nozzle rows W at both ends in the moving direction, and in order from one end side to the other end side between the two white ink nozzle rows W. , A black ink nozzle row K, a cyan ink nozzle row C, a magenta ink nozzle row M, and a yellow ink nozzle row Y are arranged. Each nozzle row includes a plurality (180 in this embodiment) of nozzles that are ejection openings for ejecting each color of UV ink.

  The plurality of nozzles in each nozzle row are aligned at a constant interval (nozzle pitch: k · D) along the transport direction. Here, D is the minimum dot pitch in the carrying direction (that is, the interval at the highest resolution of dots formed on the medium). K is an integer of 1 or more. For example, when the nozzle pitch is 180 dpi (1/180 inch) and the dot pitch in the transport direction is 720 dpi (1/720 inch), k = 4.

  The nozzles in each nozzle row are assigned a smaller number as the nozzle is located downstream in the transport direction. Each nozzle is provided with a piezo element (not shown) as a drive element for discharging UV ink from each nozzle. By driving this piezo element with a drive signal, droplet-like UV ink is ejected from each nozzle. The discharged UV ink lands on the medium and forms dots.

<Arrangement of irradiation unit>
The pre-curing irradiation units 41a and 41b are provided adjacent to the outer sides of the white ink nozzle rows W positioned at both ends of the CMYKW nozzle rows arranged in the intersecting direction, and sandwich the six nozzle rows CMYKW. Are arranged as follows. For this reason, the carriage 21 is configured to be able to irradiate UV even with ink ejected while moving in either direction from one end side to the other end side or from the other end side to the one end side. Has been.
Further, the main curing irradiation unit 43 is formed longer than the width of the medium to be printed, and is disposed downstream of the head 31 in the transport direction.

<About temporary curing and main curing>
In the present embodiment, the dots are cured by irradiating UV to the UV ink that has landed on the medium. In the printer 1 of this embodiment, the irradiation unit 40 includes provisional curing irradiation units 41a and 41b that perform UV irradiation for temporary curing of UV ink, and a main curing irradiation unit 43 that performs UV irradiation for main curing. Two-stage curing is performed. Temporary curing is to cure the surface area of the dots in order to suppress the flow of UV ink that has landed on the medium (spreading of dots) or to prevent ink bleeding between dots. Curing is for completely curing the UV ink. Therefore, UV irradiation energy is larger in the main curing (that is, the irradiation amount is larger). The provisional curing irradiation units 41a and 41b and the main curing irradiation unit 43 are each provided with a light source for irradiating UV toward the medium.

  As shown in FIGS. 2 and 4, the temporary curing irradiation units 41 a and 41 b are mounted on the carriage 21, respectively. The pre-curing irradiation units 41 a and 41 b move in the movement direction integrally with the head 31 as the carriage 21 moves. In other words, when the nozzle rows of each color of the head 31 reciprocate, the temporary curing irradiation units 41a and 41b reciprocate while maintaining the relative positions with respect to the nozzle rows of each color. At this time, UV is irradiated toward the medium from the pre-curing irradiation portions 41a and 41b. Specifically, UV is irradiated from the pre-curing irradiation unit 41a during the forward movement period, and UV is irradiated from the temporary curing irradiation unit 41b during the backward movement period. Thus, temporary hardening is performed in the same pass as forming dots. The light sources of the pre-curing irradiation units 41a and 41b are isolated from the head 31 by being accommodated in the pre-curing irradiation units 41a and 41b, respectively. This prevents the UV light emitted from the light source from leaking to the lower surface of the head 31, thereby preventing the UV ink from curing near the opening of each nozzle formed on the lower surface (nozzle clogging). is doing.

  The main curing irradiation unit 43 is provided on the downstream side in the transport direction from the head 31, and the length in the movement direction is longer than the width of the medium to be printed. Then, the main curing irradiation unit 43 irradiates the medium with UV without moving. With this configuration, when the medium on which dots are formed by the pass is conveyed to the bottom of the main curing irradiation unit 43 by the conveying operation, the medium is irradiated with UV from the main curing irradiation unit 43.

  In the present embodiment, light emitting diodes (LEDs) are used as the light sources of the pre-curing irradiation units 41a and 41b. The LED can easily change the irradiation energy by controlling the magnitude of the input current. A lamp (metal halide lamp, mercury lamp, etc.) is used as the light source of the main curing irradiation unit 43.

<Print modes that can be printed with Printer 1>
The printer 1 according to the present embodiment has a print mode that can be appropriately changed by a user's operation or based on set printing conditions. As printing modes, there are multiple types of printing modes such as a printing mode used when printing in a shorter time and a printing mode for printing higher quality images. Each printing mode transports media. At least one of the transporting operation and the dot forming operation of ejecting ink while moving the nozzle to form dots is different from each other.

Hereinafter, an example of a print mode that can be printed by the printer 1 will be described.
FIG. 5 is a diagram for explaining the carrying operation and the dot forming operation in the band printing mode. FIG. 6 is a diagram for explaining the transport operation and the dot formation operation in the pseudo band printing mode. FIG. 7 is a diagram for explaining the transport operation and the dot formation operation in the interlaced printing mode. FIG. 8 is a diagram for explaining a transport operation and a dot formation operation in the overlap type band printing mode. FIG. 9 is a diagram for explaining a transport operation and a dot formation operation in the overlap type pseudo band printing mode. FIG. 10 is a diagram for explaining the transport operation and the dot formation operation in the overlap type interlaced printing mode.

  In the following description, in order to simplify the description, the number of nozzles included in each head 31 is set to be small. In the drawing, the relative positions of the nozzles and the medium are shown. In the actual printer 1, the nozzles do not move in the transport direction. Here, in order to make it easy to understand how an image is formed, an example in which dots of each color are formed in the entire print area will be described. However, when printing an image, ink is not ejected based on print data. In some cases.

  In the following description of the print mode, the nozzles are represented by squares for convenience, and the numbers written inside are numbers for specifying the nozzles for explanation. The left side of the figure shows the relative position in the transport direction of the medium and the nozzle for each pass in which the carriage 21 moves in the image forming operation, and the right side of the figure shows the printing operation at the relative position as shown on the left. Fig. 3 shows an image of an image formed when executed. Since the nozzles for ejecting the four colors of ink can form dots at the same positions with the nozzles having the same number for each color, the nozzle row for one color will be described for the CMYK nozzles.

In the diagram on the left, in the nozzle arrangement, the nozzles that eject CMYK ink are colored in dark color, the nozzles that eject white are colored in light color, and the nozzles that ejected ink are colored in the same way in each pass. Show.
In the drawing on the right side, dots formed by the ejected ink are represented by circles, and the numbers described therein indicate nozzles from which ink for forming dots has been ejected.

  The ink ejected onto the medium is temporarily cured by being irradiated with UV at the pre-curing irradiation sections 41a and 41b that have reached the position facing the ejected ink as the carriage 21 moves. UV is irradiated from the part of the medium that has reached the position facing the main curing irradiation unit 43 as it is conveyed, and the main curing is performed. In the following description, description of UV irradiation is omitted.

1. Band printing mode The band printing mode is a printing mode in which the printing speed is given priority over the image quality, and the pitch of the nozzles arranged in the transport direction matches the dot pitch of the printed image.

  As the band printing mode, for example, as shown in FIG. 5, when the carriage 21 moves once, specifically, when each nozzle row CMYK is moved forward from one end side to the other end side in the moving direction. After ejecting ink from all the nozzles (# 1 to # 6) having a raster line, the medium is transported by a distance corresponding to the length of the nozzle row in the transport direction, and then the carriage 21 is moved from the other end side. While moving to one end side, an image is printed by repeatedly forming a raster line by ejecting ink from all nozzles of each nozzle row CMYK.

  In the band print mode, printing is performed by the length of the nozzle row in the transport direction by one movement of the carriage 21, so the printing speed is fast. On the other hand, any raster line formed by dots arranged in the moving direction is formed by a single nozzle. Further, in the transport direction, raster lines formed by a single nozzle appear periodically, so that stripes caused by color unevenness are easily noticeable.

2. Pseudo-band printing mode The pseudo-band printing mode is a printing mode in which the dot pitch of the printed image is smaller than the pitch of the nozzles arranged in the transport direction, and the raster line formed by a single nozzle is The print mode is formed by arranging a plurality of rows in the transport direction.

  In the pseudo band printing mode, as shown in FIG. 6, when the carriage 21 moves once, specifically, when the carriage 21 moves forward from one end side to the other end side in the moving direction, After ejecting ink from the nozzles, the medium is transported by a distance corresponding to an integral number of the nozzle pitch in the transport direction, and then the carriage 21 is moved (returned) from the other end side to the one end side while moving each nozzle. An image is printed by ejecting ink from all nozzles of the row. In the example of FIG. 6, the medium is conveyed by a distance corresponding to 1/4 of the nozzle pitch between the forward movement and the double movement of the carriage.

  Thereafter, the raster lines are printed by repeating a minute feed of an integral number of the nozzle pitch until the space between the raster lines formed in the first forward movement is filled with the raster lines formed thereafter. After the raster lines formed in the first forward movement are filled with the raster lines formed thereafter, the medium is transported to the next printing area all at once, and then the micro feed and dot forming operation are repeated. Print the image.

  In the pseudo band printing mode, since the dot interval in the transport direction is narrower than in the band printing mode, the image becomes smooth. However, the raster lines formed by the dots arranged in the moving direction are all single as in the band printing mode. It is formed with a nozzle. In addition, since the raster lines formed by a single nozzle appear periodically in the transport direction, the stripes caused by color unevenness are easily noticeable.

3. Interlaced printing mode The interlaced printing mode is a printing method in which the value k indicating the ratio of the nozzle pitch to the dot pitch is 2 or more, and unrecorded raster lines are sandwiched between raster lines recorded in one pass. Means. In interlace printing, each time a sheet is transported in the transport direction by a constant transport amount F, each nozzle records a raster line immediately upstream of the raster line recorded in the immediately preceding pass. In order to perform recording with a constant carry amount in this way, (1) the number N (integer) of nozzles that can eject ink is relatively prime to the value k, and (2) the carry amount F is N. The condition is that D is set (D: dot pitch).

  As an example of the interlaced printing mode, for example, as shown in FIG. 7, first, when the carriage 21 is moved forward from one end side to the other end side at the first movement of the carriage 21, each nozzle row is positioned upstream in the transport direction. Raster lines are formed by ejecting ink from several nozzles. Thereafter, the medium is transported by a predetermined amount in the transport direction, and at the time of backward movement, a raster line is formed by a nozzle different from the nozzle that formed the first raster line, adjacent to the first raster line formed. Next, the medium is transported by a predetermined amount in the transport direction, and the nozzle that is different from the nozzle that forms the raster line formed at the time of backward movement adjacent to the raster line formed at the time of backward movement during the second forward movement To form a raster line. By repeating such a predetermined amount of conveying operation of the medium and a dot forming operation in which raster lines adjacent in the conveying direction are formed by different nozzles, the previously formed raster lines become different nozzles. An image is formed by being filled with the formed raster line.

  In the example of FIG. 7, after forming a raster line by ejecting ink only from the third nozzle # 3 provided on the most upstream side during the first forward movement, the medium is conveyed by a distance corresponding to the three raster lines, While the carriage 21 is double-moved, the raster line is formed by ejecting ink from the second nozzle # 2 adjacent to the downstream side in the transport direction of the raster line formed during the forward movement. At this time, ink is also ejected from the third nozzle # 3 to form a raster line.

  Next, the medium is conveyed again by a distance corresponding to three raster lines, and ink is ejected from the first nozzle # 1 and the second nozzle # 2 adjacent to the downstream side in the conveyance direction of the raster line formed during the backward movement. To form a raster line. At this time, ink is also ejected from the third nozzle # 3 to form a raster line.

  In the interlaced printing mode, the raster lines adjacent to each other in the transport direction are formed by different nozzles. Therefore, the variation in nozzle pitch and the variation in the ink ejection characteristics of the nozzles are less noticeable than in the band printing mode and the pseudo band printing mode. Since the raster lines formed by the dots arranged in the moving direction are formed by a single nozzle in the same manner as in the band printing mode and the pseudo band printing mode, the stripes caused by color unevenness are relatively conspicuous. .

4). Overlap type band print mode The overlap type band print mode has a plurality of (two in this case) raster lines formed by a single nozzle in the band print mode, as shown in FIG. This is a so-called overlap type printing mode formed by nozzles.

In the overlap type band printing mode, the nozzles of the nozzle row are used in half in the transport direction.
For example, as shown in FIG. 8, first, the carriage 21 is moved to the print area of the conveyed medium while ejecting ink from approximately half of the nozzles in the nozzle row located on the upstream side in the conveyance direction. A raster line is formed. In the example of FIG. 8, since the nozzle row has six nozzles, dots are formed by ejecting ink from the three nozzles # 4, # 5, and # 6 located on the upstream side. At this time, in the moving direction, the dots are wider than the dot interval of the raster line formed in the band printing mode, for example, every other dot is formed.

  Next, after the medium is transported by a distance corresponding to half the length of the nozzle row in the transport direction, ink is ejected from all the nozzles to form a raster line. At this time, each nozzle forms every other half of the dots forming the raster line. By this dot forming operation of the pass, raster lines that form new raster lines are formed at intervals in the moving direction in half of the nozzles on the upstream side, and formed in the previous pass with half of the nozzles on the downstream side. Dots are formed between the raster lines to complete the raster line.

  Thereafter, after the medium is transported by a distance corresponding to half the length of the nozzle row in the transport direction, ink is ejected from all nozzles to form a raster line with a space of one dot in the transport direction. The image is printed by repeating the operation.

  In the overlapping band printing mode, a raster line is formed by the ink ejected from two nozzles, so the stripes due to color unevenness are less noticeable and the image quality is better than the band printing mode that does not overlap. Printing speed is reduced because the rows are used half by half.

5). Overlapping Pseudo Band Printing Mode Overlapping pseudo band printing mode includes a plurality of raster lines formed by a single nozzle in a non-overlapping pseudo band printing mode as shown in FIG. This is a so-called overlap mode printing mode formed by two nozzles.

  The overlap type pseudo band printing mode is a printing mode in which the dot pitch of the printed image is smaller than the nozzle pitch arranged in the transport direction, and one raster line is ejected from a plurality of nozzles. It is formed of ink and formed in a plurality of rows in the transport direction.

  In the overlap type pseudo band printing mode, for example, as shown in FIG. 9, a plurality of each nozzle row has at the time of forward movement from one end side to the other end side in the moving direction by the first movement of the carriage 21. Ink is ejected from several nozzles (# 2, # 3) located on the upstream side of the nozzles (here, three nozzles). At this time, in the moving direction, dots are formed wider than the dot interval of the raster line formed in the pseudo band printing mode that does not overlap, for example, every other pixel.

  Next, the medium is transported by a distance corresponding to the dot pitch in the transport direction, and then the carriage 21 is moved from the other end side to the one end side (double-acting) while being moved to the same nozzle as the nozzle that formed the dots during the forward movement. Then, ink is ejected adjacent to the upstream side of the already formed dots in the transport direction to print an image. After that, until the gap between the raster lines formed in the first forward movement is filled with the raster lines to be formed thereafter, the fine pitch feed is repeated, and the dots separated from each other by one pixel in the moving direction. Print the raster line configured in.

  Further, when the medium is conveyed by a distance corresponding to the dot pitch, the nozzle is arranged at a position facing the raster line formed by the nozzle located on the upstream side, and the upstream side is moved by the next movement of the carriage. A raster line is completed by forming dots between dots formed by the nozzles located in the nozzles. In the example of FIG. 9, the first nozzle # 1 and the second nozzle # 2 are adjacent to the dots formed by the second nozzle # 2 and the third nozzle # 3 during the first forward movement in the moving direction. Dots are formed to form raster lines.

  After that, when the dot forming operation is continued while repeating the minute feed for the dot pitch, the raster line in which the dots formed by the first nozzle # 1 and the second nozzle # 2 are alternately arranged, and the second nozzle # A raster line in which dots formed by 2 and the third nozzle # 3 are alternately arranged is completed, and an unfinished raster line formed by only the third nozzle is formed on the upstream side. Therefore, in order to complete an unfinished raster line with the first nozzle # 1, the medium is transported by a distance that is the sum of the nozzle pitch and the dot pitch, and the dot forming operation is executed.

6). Overlapping Interlaced Printing Mode Overlapping interlaced printing mode is a multi-line (two here) raster line formed by a single nozzle in the interlaced printing mode as shown in FIG. This is a so-called overlap type printing mode formed by nozzles.

  For example, as shown in FIG. 10, first, in the first movement of the carriage 21, at the time of forward movement from one end side to the other end side, ink is ejected only from the third nozzle facing the print area of the medium, An incomplete raster line having a wide dot interval in the moving direction is formed. Thereafter, the medium is transported by the dot pitch in the transport direction, and when returning, ink is ejected from only the third nozzle to form an incomplete raster line having a wide dot interval adjacent to the first formed dot. .

  Next, the medium is transported by twice the dot pitch in the transport direction, and in the forward movement, ink is ejected from the second nozzle and the third nozzle facing the print area of the medium, and an unfinished raster having a wide dot interval Form a line. Thereafter, when the medium is transported by the dot pitch in the transport direction, the second nozzle is disposed at a position facing the unfinished raster line having a large dot interval formed by the third nozzle first. For this reason, at the second return, ink is ejected from the second nozzle and the third nozzle facing the print area of the medium. Ink ejected from the second nozzle is first formed by the third nozzle. A raster line is completed by forming adjacent dots between the dots. By repeating such a medium transport operation and a dot formation operation, dots formed adjacent to the transport direction and dots formed adjacent to the movement direction are formed by relatively different nozzles. Therefore, the striped density unevenness due to the difference in the ink ejection characteristics of the nozzles is less noticeable. On the other hand, the amount of conveyance at one time is reduced, and the number of raster lines completed by one movement of the carriage is reduced, so that the printing speed is reduced.

<Printing on transparent media>
When printing on a transparent film as a transparent medium, the printer 1 can print an image for viewing the printed image through the transparent film. That is, since the medium is transparent, the printed image can be viewed through the transparent film from the printed surface side or from the transparent film side opposite to the printed surface. For this reason, when the medium is a transparent film, an image for viewing through the transparent film can be printed.

FIG. 11 is a diagram for explaining an example of processing when printing on a transparent medium by a printer.
Specifically, as shown in FIG. 11, when a user of the printer 1 selects a transparent film as a printing medium (S11, S12), an image to be printed is an image for direct viewing from the printing surface side. Or an image for viewing through a transparent film (S13), the print mode is changed (S15, S16).

  Generally, a printer is required to print a higher quality image faster. When printing on a medium such as paper and viewing an image printed from the printing surface, striped density unevenness is easily noticeable due to irregular reflection. For this reason, when printing a high-quality image, for example, the printing speed is reduced, and an interlaced printing mode or an overlapping printing mode is appropriately selected according to the requested image quality. Further, when printing text or the like, the printing time is shortened by printing in, for example, the band printing mode while allowing the occurrence of striped density unevenness or the like.

  However, when an image printed on a transparent film is viewed through the transparent film, the surface becomes a film surface and the surface has a high degree of smoothness, so that there is no irregular reflection, and stripe density unevenness is not noticeable.

  For this reason, in the printer 1, a back printing mode as a first printing mode for printing an image for viewing through a transparent film and a front printing mode as a second printing mode for printing an image for direct viewing are set. ing.

  For example, an interlaced printing mode is set as a front printing mode for printing an image for direct viewing (direct viewing image), and a back printing mode for printing an image for viewing through a transparent film (image through a film) The band print mode or the pseudo band print mode is set.

  In addition, the front print mode and the back print mode are any of the band print mode, the pseudo band print mode, and the interlaced print mode, and the overlap mode print mode is set as the front print mode. The reverse printing mode may be set to a non-overlapping printing mode.

  Further, both the front print mode and the back print mode are overlap mode print modes, and the front print mode is the number of times the carriage 21 moves to form one raster line dot than the back print mode, or It may be set so that the number of nozzles forming one raster line dot increases.

<First embodiment>
Specifically, when printing an image on a transparent film, first, the user designates a transparent film as a medium in the computer 80 connected to the printer 1 so as to be communicable, and the image to be printed is an image for direct viewing. An image for viewing through the film is selected and an operation for executing printing is performed.

  At this time, when data of an image to be printed is specified and information indicating that the image is printed as an image for direct viewing is input, print data for printing a normal image of the image specified by the printer driver Is generated, print information for printing in the front print mode is added to the print data, and the print data is sent to the printer 1.

  FIG. 12 is a diagram for explaining a transport operation, a dot formation operation, and a state in which dots are formed in the overlapped interlaced print mode executed as the front print mode. In FIG. 12, the CMYK image and the background image are shown separately, but in actuality, the CMYK image is printed on the background image.

  The printer 1 receives the print data and the print information (S11), and based on the received print information, the controller determines whether to print on a transparent medium or to print an image for viewing through the medium. (S12, S13). In this case, it is determined that an image for direct viewing is printed on the transparent film, and a printing program in a front printing mode for printing the image for direct viewing is executed (S15). At this time, for example, when the overlapped interlaced printing mode is set as the front printing mode, the transparent film carrying operation and the dot forming operation as shown in FIG. 12 are executed to print the image. The overlapped interlaced printing mode shown in FIG. 12 is different from the overlapped interlaced printing mode described above with reference to FIG. 10 in that a background image using white ink is printed. That is, since the medium of the transparent film is transparent, a portion where CMYK ink is not ejected remains transparent. For this reason, it is difficult to see the printed image clearly from the transparent part because the objects existing on the other side of the film can be seen through the film. Therefore, the front print mode of this embodiment is set to print the image of each component of CMYK after printing the white background image on the surface of the transparent film so that the image looks the same as when printed on white paper. ing.

  In the example of FIG. 12, the white ink nozzle row W located on the leading end side in the movement direction of the carriage 21 is used, and the transport direction of the white ink nozzle row W is up to the eighth pass (four forward movements and four double movements). The background image is printed with the upstream nozzle in FIG. 9, and the background image is printed with the upstream nozzle from the ninth pass, while the CMYK component images on the already printed background image are printed with the downstream nozzle. Print.

  On the other hand, when the user inputs from the computer 80 image data to be printed and information indicating that the image is to be printed as an image for viewing through a transparent film, a mirror image of the image designated by the printer driver is printed. Print data is generated, print information for printing in the reverse print mode is added to the print data, and the print data is sent to the printer 1.

  In the printer 1 that has received the print data and the print information, the controller 60 executes a print program for printing a mirror image based on the print information (S16). At this time, for example, when the non-overlapping interlaced printing mode is set as the back printing mode, the transparent film carrying operation and the dot forming operation as shown in FIG. 13 are executed to print the image.

  FIG. 13 is a diagram for explaining a transport operation, a dot formation operation, and a state in which dots are formed in the non-overlapping interlaced print mode executed as the back printing mode. In FIG. 13, the CMYK image and the background image are shown separately, but in actuality, the CMYK image is printed on the background image.

  The non-overlapping interlaced printing mode shown in FIG. 13 is different from the non-overlapping interlaced printing mode described with reference to FIG. 7 in that a background image using white ink is printed.

  In the image to be viewed through the transparent film, the portion where the CMYK ink is not ejected remains transparent, so the transparent portion can see what is on the other side of the film and the printed image can be seen clearly. difficult. For this reason, in the back printing mode of this embodiment, a white background image is printed over the entire print area from the top of the CMYK image formed on the transparent film so that the image looks the same as when printed on white paper. Is set to

In the example of FIG. 13, first, up to the fourth pass (twice of the forward movement and twice of the double movement), the image of each component of the CMYK image is generated by the upstream nozzle in the transport direction of the CMYK color ink nozzle row. Printing and printing CMYK images with the nozzles on the upstream side from the fifth pass, while the nozzles on the downstream side of the white ink nozzle row located on the rear end side in the movement direction of the carriage 21 are white on the entire printing area The background image is printed by discharging the ink.
Here, as an image to be viewed through a transparent medium, for example, when the user inputs information for printing a symmetrical design image, a normal image is printed instead of a mirror image based on the information input by the user. You may do it.

FIG. 16 is a diagram for explaining a modified example of processing when printing on a transparent medium by a printer.
In the above embodiment, the transparent medium is selected as the medium by the user, and an example in which an image to be viewed through the transparent medium is printed or an image to be directly viewed is input is described. As shown in FIG. 16, when information for printing a mirror image is input by the user, based on the input information (S23), the back printing mode may be executed in the printer 1 (S26).

<Modification of the first embodiment>
In the first embodiment, an example in which an overlapped interlaced printing mode is set as the front printing mode and an interlaced printing mode without overlapping is set as the back printing mode has been described. However, the front printing mode and the back printing are described. All of the modes are set to overlap interlaced printing mode, and the number of nozzles that eject ink forming dots constituting one raster line is different between the front printing mode and the back printing mode. It may be set to. For example, in the front printing mode, one raster line is formed by ink ejected from four nozzles, and in the rear printing mode, one raster is formed by ink ejected from two nozzles as shown in FIG. It may be set to form a line. Also in this case, in the front print mode, the background image is printed before the CMYK image, and in the back print mode, the background image is printed after the CMYK image is printed.

<Second embodiment>
The second embodiment is an example in which a print mode that does not overlap is set for both the front print mode and the back print mode.
In the second embodiment, for example, a non-overlapping interlaced printing mode is set as the front printing mode, and a non-overlapping band printing mode is set as the back printing mode.

When a user designates a transparent film as a medium from the computer 80 and selects an image to be directly viewed as an image to be printed and performs an operation for printing, the printer driver displays a normal image of the designated image. Print data for printing is generated, print information for printing in the front print mode is added to the print data, and the print data is sent to the printer 1.
In the printer 1 that has received the print data and the print information, the controller executes a print program for printing in the interlaced print mode in which the normal images do not overlap based on the print information (S15).

  FIG. 14 is a diagram for explaining a transport operation, a dot formation operation, and a state in which dots are formed in a non-overlapping interlaced print mode executed as the front print mode. In FIG. 14, the CMYK image and the background image are shown separately, but in actuality, the CMYK image is printed on the background image.

  In the printer 1, a transparent film transport operation and a dot formation operation as shown in FIG. 14 are executed to print an image. The non-overlapping interlaced printing mode shown in FIG. 14 is different from the non-overlapping interlaced printing mode described above with reference to FIG. 13 in that the background image using white ink is printed before the CMYK image is printed.

  In the example of FIG. 14, the leading end side in the moving direction of the carriage 21 until the fourth pass (two forward movements and two double movements) so that the image printed on the transparent film looks the same as when printed on a blank sheet. A white image is ejected using a nozzle on the upstream side of the white ink nozzle row W positioned at a position to print a background image. Then, the background image is printed with the ink ejected from the nozzle on the upstream side of the white ink nozzle row W from the fifth pass, and each component of the CMYK image is printed on the downstream side nozzle in the transport direction of the ink nozzle row of each color of CMYK. Is printed on the already printed background image.

On the other hand, when the user inputs from the computer 80 image data to be printed and information indicating that the image is to be printed as an image for viewing through a transparent film, a mirror image of the image designated by the printer driver is printed. Print data is generated, print information for printing in the reverse print mode is added to the print data, and the print data is sent to the printer 1.
In the printer 1 that has received the print data and the print information, the controller executes a print program in a band print mode that does not overlap based on the print information (S16).

FIG. 15 is a diagram for explaining a transport operation, a dot formation operation, and a state in which dots are formed in a non-overlapping band printing mode executed as the back printing mode.
In the printer 1, a transparent film transport operation and a dot formation operation as shown in FIG. 15 are executed to print an image. The non-overlapping band printing mode shown in FIG. 15 is different from the non-overlapping band printing mode described with reference to FIG. 5 in that the background image using white ink is printed before the CMYK image is printed.

  In the example of FIG. 15, the first pass passes the CMYK image at the upstream nozzle in the transport direction of the CMYK ink nozzle row so that the image printed on the transparent film looks the same as when printed on a blank sheet. The image of each component is printed, and after the second pass, the image of each component of the CMYK image is printed by the upstream nozzle in the transport direction of the CMYK color ink nozzle row, and the trailing edge in the movement direction of the carriage 21 White ink is ejected using the nozzles on the downstream side of the white ink nozzle row W positioned on the side, and the background image is printed over the entire print area.

<Third embodiment>
In the third embodiment, a print mode that does not overlap is set for both the front print mode and the reverse print mode. In the front print mode, the carriage movement direction when ejecting ink is the same direction (predetermined direction). In the reverse printing mode, ink is ejected both when the carriage moves in a predetermined direction and when the carriage moves in a direction opposite to the predetermined direction. That is, the front print mode is set to the Uni-d print mode, and the back print mode is set to the Bi-d print mode.

  In the third embodiment, when the user designates a transparent film as a medium from the computer 80, selects an image to be directly viewed as an image to be printed, and performs an operation to execute printing, the printer driver designates the transparent film. Print data for printing a normal image of the printed image is generated, print information for printing in the front print mode is added to the print data, and the print data is sent to the printer 1.

  In the printer 1 that has received print data and print information for printing an image for direct viewing, based on the print information, the controller 60 is in an interlaced print mode in which normal images do not overlap and is in a Uni-d print mode. The printing program for printing is executed (S15). The images formed in the front printing mode and the nozzles used in the third embodiment are the same as in FIG. 14 showing the front printing mode of the second embodiment, but the carriage in the transparent film transport operation and dot formation operation 21 is different from the moving operation. Specifically, in the front print mode of the second embodiment, a transport operation for transporting the medium is performed every time the carriage moves forward and double. However, in the front print mode of the third embodiment, the carriage travels. It is set to perform a transport operation for transporting the medium after moving and double-acting, that is, after the carriage 21 reciprocates.

  The printer 1 that has received print data and print information for printing an image to be viewed through the medium is in an interlaced print mode in which the controller does not overlap mirror images based on the print information, and Bi-d printing is performed. A printing program for printing in the mode is executed (S16). The transport operation and dot forming operation of the transparent film in the back printing mode in the third embodiment are the same as those in FIG. 13 shown as the back printing mode in the first embodiment.

  According to the printing system 100 of the above-described embodiment, the printing mode for printing an image for viewing through the transparent film on the transparent film and the back printing mode which is a printing mode for printing a mirror image on the transparent medium, At least one of the transport operation and the dot formation operation is different between the print mode for printing an image for viewing and the front print mode which is a print mode for printing a normal image on a medium. Therefore, a conveyance operation and a dot formation operation suitable for printing a mirror image on an image for viewing through a transparent film or on a transparent film, and for printing a normal image on an image for viewing directly or on a transparent film, respectively. Can be printed. For this reason, both when printing a mirror image on an image for viewing through a transparent film or on a transparent film, and when printing a normal image on an image for direct viewing or on a transparent film, the stripes caused by color unevenness are conspicuous. It is possible to print difficult images faster.

  In particular, when printing on a medium such as paper and viewing an image printed from the printing surface, striped density unevenness tends to be noticeable due to irregular reflection, but the image printed on the transparent film is viewed through the transparent film. In some cases, the surface becomes a film surface and the surface has a high degree of smoothness, so that it does not diffusely reflect, and stripe density unevenness is not noticeable. For this reason, as in the first embodiment, the number of times the nozzles are moved to form one raster line arranged in the intersecting direction in the dot formation operation in the front print mode is set as the dot formation in the back print mode. By increasing the number of operations, it is possible to form an image in which density unevenness is less noticeable in the front printing mode.

  Further, density unevenness is easily noticeable when an image printed in the reverse printing mode is directly viewed, but density unevenness is not easily noticeable when a printed image is viewed as a normal image through a transparent film. For this reason, when printing a mirror image and printing an image for viewing through a transparent film, the image is printed faster by reducing the number of times the nozzle is moved to form one raster line. Is possible.

  In particular, as in the first to third embodiments, a single raster line constituting an image to be printed in a reverse printing mode in which density unevenness is less noticeable when viewed through the medium is used for one movement of the nozzle. By forming the image, it is possible to print an image faster.

  Further, as in the second embodiment, the raster line of the image printed in the front printing mode in which the image for direct viewing is printed is displayed in the reverse printing mode in which the image for viewing through the transparent film is printed. If printing is performed so that the interval in the transport direction is narrower than the raster line of the printed image, it is possible to print an image in which density unevenness is less noticeable.

  Further, as in the third embodiment, when an image printed in the front printing mode is moved in the same direction when ejecting ink so as to form a raster line, the nozzle as in the back printing mode is used. In both of the reciprocating operations, since the accuracy of the positions where dots are formed is higher than when ink is ejected, it is possible to print a better image.

  On the other hand, the image printed in the reverse printing mode has alternating nozzle movement directions when ejecting ink to form a raster line. Therefore, when viewing the printed image through a transparent film, the density It is possible to print an image with less unevenness more quickly.

  Further, as in the modification of the first embodiment, the number of nozzles that eject ink to form a raster line in which dots are arranged in the intersecting direction in the dot forming operation in the front print mode is set to the back print mode. By increasing the number of dot forming operations, it is possible to form an image in which density unevenness is less noticeable in the front printing mode. In addition, when the image in the back printing mode is viewed directly, uneven density is conspicuous, but the image printed on the transparent film is an image for viewing through the transparent film or a mirror image, so the image was viewed through the transparent film. In this case, uneven density is not noticeable. For this reason, when printing an image for viewing through a transparent film or a mirror image, it is possible to print the image faster by reducing the number of nozzles forming one raster line.

  In particular, as in the first embodiment, when one raster line constituting an image to be printed in the back printing mode in which density unevenness is less noticeable when viewed through the medium is formed with a single nozzle, It is possible to print an image quickly.

  Also, in the back printing mode, after printing the image, the background image that is the background of the image is printed, so even when the image is printed on the transparent film, when the image is viewed through the transparent film, When the image is printed on the background image, there is no transparent portion in the print area where objects existing on the other side of the transparent film can be seen. For this reason, it is possible to print an image that looks clearer.

  Also, in the front print mode, a background image that is the background of the image is printed before printing the image. Therefore, even if the image is printed on a transparent film, the background is displayed when the printed image is viewed directly. When the image is printed on the image, there is no transparent portion in the print area where objects existing beyond the transparent film can be seen. For this reason, it is possible to print an image that looks clearer.

  Furthermore, since the background image was printed by discharging white ink over the entire print area, even if the image was printed on a transparent film, it is possible to print the same image as the image printed on the white paper. is there.

=== Other Embodiments ===
Although a printer or the like as one embodiment has been described, the above embodiment is for facilitating the understanding of the present invention, and is 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. In particular, the embodiments described below are also included in the present invention.

<About the printing system>
In the above-described embodiment, the printing system 100 including the printer 1 and a computer that is communicably connected to the printer 1 has been described as an example. However, the present invention is not limited to this. For example, the printer may have an interface with a memory or the like and an input operation unit, and may be executed only by a printer that can print by specifying image data in the memory or the like by an operation from the input operation unit. .

<About nozzle>
In the above-described embodiment, ink is ejected using a piezoelectric element (piezo 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.

<About ink>
In the above-described embodiment, ink that is cured by receiving ultraviolet (UV) irradiation (UV ink) is ejected from the nozzle. However, the liquid ejected from the nozzle is not limited to such an ink, and a liquid that is cured by being irradiated with an electromagnetic wave other than UV (for example, visible light) may be ejected from the nozzle. In this case, electromagnetic waves (such as visible light) for curing the liquid may be irradiated from the provisional curing irradiation units 41 a and 41 b and the main curing irradiation unit 43.

1 printer, 10 transport unit, 11 paper feed roller,
13 transport roller, 14 platen, 15 paper discharge roller,
20 carriage unit, 21 carriage, 24 guide shaft,
30 head units, 31 heads, 40 irradiation units,
41a, 41b Pre-curing irradiation part, 43 Curing irradiation part,
50 detector group, 53 paper detection sensor, 54 optical sensor 60 controller, 61 interface unit, 62 CPU,
63 memory, 64 unit control circuit,
80 computers, 100 printing systems

Claims (8)

A printing apparatus that prints an image on a medium transported in a transport direction by ejecting ink from the nozzles while forming a dot while moving in a crossing direction intersecting the transport direction.
A first print mode for printing a mirror image of a predetermined image on the transparent medium as the medium as the image; and a second print mode for printing a normal image of the predetermined image on the medium as the image. ,
The first print mode and the second print mode include at least one of a transport operation for transporting the medium and a dot formation operation for ejecting ink while moving the nozzle to form dots. A printing apparatus characterized by being different from each other. The printing apparatus according to claim 1,
The dot forming operation in the second printing mode is the number of times the nozzle is moved to form one dot row that constitutes the image and in which the dots are arranged in the intersecting direction. The number of the dot forming operations is more than the number of the dot forming operations. The printing apparatus according to claim 1,
The intervals in the transport direction of the plurality of dot rows that constitute the image and in which the dots are arranged in the intersecting direction are more in the transport operation in the second print mode than in the transport operation in the first print mode. A printing apparatus that conveys the medium so as to be narrow. The printing apparatus according to claim 1,
In the second printing mode, the dot forming operation forms a dot row in which the dots are arranged in the intersecting direction forming the image by ejecting ink when the nozzle moves in a predetermined direction,
The dot forming operation in the first printing mode is characterized in that the dot row is formed by ejecting ink when the nozzle is moved in a predetermined direction and in a direction opposite to the predetermined direction. The printing apparatus according to claim 1,
The dot forming operation in the second printing mode and the dot forming operation in the first printing mode are different from each other in one dot row that constitutes the image and in which the dots are arranged in the intersecting direction. Formed by ejecting ink from the nozzles,
The printing apparatus according to claim 1, wherein the number of the nozzles that eject ink to form the one dot row is greater in the second printing mode than in the first printing mode. The printing apparatus according to claim 5,
In the dot forming operation in the first printing mode, a printing apparatus is characterized in that ink is ejected from a single nozzle in order to form the one dot row. A printing apparatus according to any one of claims 1 to 7,
At least one of the first print mode and the second print mode prints a background image as a background of the printed image. A printing apparatus that prints an image on a medium transported in a transport direction by ejecting ink from the nozzles while forming a dot while moving in a crossing direction intersecting the transport direction.
A first print mode for printing the image for viewing through the transparent medium on the transparent medium as the medium, and a second print mode for printing the image for direct viewing;
The first print mode and the second print mode include at least one of a transport operation for transporting the medium and a dot formation operation for ejecting ink while moving the nozzle to form dots. A printing apparatus characterized by being different from each other.