JP2013184417A - Printing apparatus and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration in a printing image.SOLUTION: A printing apparatus includes: a platen that supports and heats a medium; a head that is supported by the platen and prints an image in a portion located in a print region in a heated medium; and a conveyance part that intermittently conveys the medium for each length in a conveyance direction of the print region along in the conveyance direction. The length in the conveyance direction of the print region is shorter than a length in the conveyance direction of the platen and longer than half the length. The print region is located closer to an upstream side than the center of the platen in the conveyance direction.

Description

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

  As an example of a printing apparatus, an ink jet printer that performs printing by discharging a liquid such as ink onto a medium such as paper is known. The inkjet printer includes a platen that supports and heats the medium, a head that is supported by the platen and prints an image on the heated medium, and a conveyance unit that intermittently conveys the medium in the conveyance direction. It has (for example, patent document 1).

JP 2011-46096 A

In this printing apparatus, when the medium is intermittently conveyed in the conveyance direction by the conveyance unit, the medium moves along the conveyance path and stops on the platen. When the medium is stopped on the platen, the medium is heated by the platen, and printing is performed by the head, so that an image is formed at a portion located in the print area of the medium. At this time, the length of the printing region in the transport direction may be shorter than the length of the platen in the transport direction. In such a case, the part located outside the print area of the medium is only heated without forming an image. When printing is subsequently performed after intermittent conveyance, there is a case where an image is formed on a portion that has already been heated before printing of the medium and a case where an image is formed on a portion that is not heated, and there is a difference in print image quality. It will occur. In particular, in the former case, since the liquid is ejected to the medium that has been excessively dried before printing, the medium is greatly expanded and the landing position is greatly changed due to more immersion of the landed liquid. For example, the print image quality is deteriorated.
The present invention has been made in view of such problems, and an object of the present invention is to suppress deterioration in print image quality.

The main invention for solving the above problems is:
A platen for supporting and heating the medium;
A head that prints an image on a portion of the heated medium that is supported by the platen and that is located within the print area;
A transport unit that intermittently transports the medium for each length in the transport direction of the print region along the transport direction;
The length of the print area in the transport direction is shorter than the length of the platen in the transport direction, and longer than half of the length,
The printing apparatus is characterized in that the printing area is located upstream of the center of the platen in the transport direction.
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 1000. FIG. FIG. 4 is a diagram illustrating an outline of processing performed by a printer driver. 1 is a schematic diagram illustrating a configuration of a printer. 6 is a flowchart for explaining various operations performed by the printer 1 for each target portion of roll paper. 5A to 5F are diagrams illustrating a series of operations in the comparative example. 6A to 6F are diagrams for describing a series of operations in the present embodiment. It is the schematic which shows the structure of the adsorption | suction unit 75. FIG.

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

A platen that supports and heats the medium;
A head that prints an image on a portion of the heated medium that is supported by the platen and that is located within the print area;
A transport unit that intermittently transports the medium for each length in the transport direction of the print region along the transport direction;
The length of the print area in the transport direction is shorter than the length of the platen in the transport direction, and longer than half of the length,
The printing apparatus is characterized in that the printing area is located upstream of the center of the platen in the transport direction.
According to such a printing apparatus, when printing is performed by intermittently transporting continuously after printing, an image is always formed on a portion that is not heated, so that deterioration in print image quality can be suppressed.

Moreover, it is such a printing apparatus,
An adsorbing part for adsorbing the medium supported by the platen to the platen;
Other than the print area of the heated medium supported and supported by the platen, rather than the adsorbing force that the adsorbing part adsorbs the portion of the heated medium located in the print area supported by the platen. And a controller that controls a portion located within the region so that the suction force attracted by the suction portion is increased.
According to such a printing apparatus, the bending of the medium can be suppressed.

Further, printing an image with a head on a portion of the heated medium that is supported and heated by the platen that is supported and heated and located in the print region;
Intermittently transporting the medium by a transport unit for each length in the transport direction of the print area along the transport direction,
The length of the print area in the transport direction is shorter than the length of the platen in the transport direction, and longer than half of the length,
The printing method is characterized in that the printing area is located closer to the upstream side than the center of the platen in the transport direction.
According to such a printing method, it is possible to suppress deterioration in print image quality.

=== Embodiment ===
<<< Printing system configuration >>>
FIG. 1 is a diagram illustrating the configuration of the printing system 1000. A printing system 1000 according to this embodiment includes a printer 1 as an example of a printing apparatus, a host computer 1100 as a printing control apparatus, a display apparatus 1200, an input apparatus 1300, and a recording / reproducing apparatus 1400.

  The host computer 1100 is connected to the printer 1, the display device 1200, the input device 1300, and the recording / playback device 1400 so that data communication can be performed by wire such as a cable or wirelessly. The computer device 1100 stores an interface unit for transmitting / receiving data to / from the printer 1, a CPU as an arithmetic processing device for controlling the entire host computer 1100, and a program such as a printer driver. And a computer-side memory that secures a work area and the like, and print data of an image to be printed by the printer 1 is generated and output to the printer 1.

The display device 1200 displays a user interface such as an application program or a printer driver.
The input device 1300 includes, for example, a keyboard and a mouse, and is used for operating an application program, setting a printer driver, and the like along a user interface displayed on the display device 1200.
The recording / reproducing device 1400 is configured by, for example, a flexible disk drive device or a CD-ROM drive device.

  A printer driver is installed in the host computer 1100 according to the present embodiment. The printer driver is a program for realizing a function of displaying a user interface on the display device 1200 and a function of converting image data output from an application program into print data. This printer driver is stored in various storage media (computer-readable recording media, etc.) such as a flexible disk and a CD-ROM. Alternatively, the printer driver can be downloaded through various communication means such as the Internet.

<About the printer driver>
FIG. 2 schematically illustrates basic processing performed by the printer driver.
In the host computer 1100, computer programs such as a video driver 1102, an application program 1104, and a printer driver 1110 are operating under an operating system installed in the host computer 1100. The video driver 1102 has a function of displaying, for example, a user interface on the display device 1200 in accordance with a display command from the application program 1104 or the printer driver 1110. The application program 1104 has a function of performing image editing, for example, and creates data (image data) related to an image. The user can give an instruction to print an image edited by the application program 1104 via the user interface of the application program 1104. Upon receiving a print instruction, the application program 1104 outputs image data to the printer driver 1110.

  The printer driver 1110 receives image data from the application program 1104, converts this image data into print data, and outputs the print data to the printer 1. Here, the print data is data in a format that can be interpreted by the printer 1 and includes various command data and pixel data. The command data is data for instructing the printer 1 to execute a specific operation. The pixel data is data relating to pixels constituting an image to be printed (printed image). For example, data relating to dots formed at positions on the medium corresponding to a certain pixel (color and size of the dots, etc.) Data).

  The printer driver 1110 includes a resolution conversion processing unit 1112, a color conversion processing unit 1114, a halftone processing unit 1116, and a rasterization processing unit 1118 in order to convert image data output from the application program 1104 into print data. I have. Hereinafter, various processes performed by the processing units 1112, 1114, 1116, and 1118 of the printer driver 1110 will be described.

  A resolution conversion processing unit 1112 performs resolution conversion processing for converting image data (text data, image data, etc.) output from the application program 1104 into a resolution for printing on a medium. With the resolution conversion process, for example, when the resolution when printing an image on a medium is specified as 720 × 720 dpi, the image data received from the application program 1104 is converted into image data with a resolution of 720 × 720 dpi. Note that the image data after the resolution conversion process is multi-gradation (for example, 256 gradations) RGB data represented by an RGB color space. Hereinafter, RGB data obtained by performing resolution conversion processing on image data is referred to as RGB image data.

  The color conversion processing unit 1114 performs color conversion processing for converting RGB data into CMYK data represented by a CMYK color space. The CMYK data is data corresponding to the ink color of the printer 1. This color conversion processing is performed by the printer driver 1110 referring to a table (color conversion lookup table LUT) in which gradation values of RGB image data and gradation values of CMYK image data are associated with each other. Through this color conversion process, RGB data for each pixel is converted into CMYK data corresponding to the ink color. The data after the color conversion processing is CMYK data with 256 gradations represented by the CMYK color space. Hereinafter, CMYK data obtained by performing color conversion processing on RGB image data is referred to as CMYK image data.

  The halftone processing unit 1116 performs a halftone process for converting high gradation number data into gradation number data that can be formed by the printer 1. The halftone processing is, for example, processing for converting data indicating 256 gradations into 1-bit data indicating 2 gradations or 2-bit data indicating 4 gradations. In this halftone process, pixel data is created by using the dither method, γ correction, error diffusion method, and the like so that the printer 1 can form dots dispersedly. When halftone processing is performed, the halftone processing unit 1116 refers to the dither table when performing the dither method, refers to the gamma table when performing γ correction, and is diffused when performing the error diffusion method. Refer to the error memory for storing the error. The data subjected to halftone processing has a resolution (for example, 720 dpi × 720 dpi) equivalent to the above-described RGB data. The halftoned data is composed of 1-bit or 2-bit data for each pixel, for example.

  A rasterization processing unit 1118 performs a rasterization process for changing matrix image data in the order of data to be transferred to the printer 1. As a result, the rasterized data is output to the printer 1.

<About printer driver settings>
A user interface of the printer driver 1110 will be described.
The user interface of the printer driver 1110 is displayed on the display device 1200 via the video driver 1102. The user can use the input device 1300 to select a print mode, resolution of an image to be printed (interval between dots when printing, 720 dpi, 1440 dpi, etc.), type of medium used for printing (plain paper, glossy paper, film, etc.) Various settings of the printer driver 1110 such as the type of image to be printed (color printing, monochrome printing, etc.) can be performed.

  In this embodiment, when the user sets the resolution of a print image on the setting screen, the printer driver 1110 forms print data corresponding to the resolution. That is, the print data includes pixel data of the set resolution, command data for instructing the head 31 (to be described later) to reciprocate along the transport direction by the number of times corresponding to the resolution, and Will be included. For example, in the case of normal image quality, command data is set so that the head 31 (carriage 42) performs the reciprocating movement four times in order to perform printing in four passes. In the case of high image quality, command data is set so that the head 31 (carriage 42) performs the reciprocating movement eight times in order to perform printing in eight passes.

  When the user sets the frame size, the print start position, etc. on the setting screen, the printer driver 1110 automatically impositions the print image based on the print start position on the platen 29, and according to the frame size. Form print data. That is, the print data includes pixel data of a print image to be imposed, command data for instructing the head unit 30 described later to form a print image from the print start position, and a transport unit described later. Command data for instructing 20 to intermittently convey the roll paper 2 for each frame along the conveyance direction is included. For example, when the frame size is set to 18 inches, command data for instructing the transport unit 20 to intermittently transport in units of 18 inches is set.

  Here, the frame is a unit of conveyance of the roll paper 2 that is intermittently conveyed, and a printing range (printing area) in which the head can record a print image on the roll paper 2 between the intermittent conveyance interruptions. It is. In the printer 1 according to the present embodiment, the maximum size of one frame is set to 36 inches.

<<< Configuration Example of Printer 1 >>>
A configuration example of the printer 1 (lateral scan type label printing machine) according to the present embodiment will be described with reference to FIGS. 1 and 3. FIG. 3 is a schematic diagram illustrating the configuration of the printer 1.
In the following description, when referring to “up and down direction” and “left and right direction”, the direction indicated by the arrow in FIG. 3 is used as a reference. Further, when referring to the “front-rear direction”, the direction orthogonal to the paper surface in FIG. 3 is shown.
Further, in the present embodiment, as an example of a medium on which the printer 1 records an image, a paper wound in a roll shape (hereinafter referred to as “roll paper (continuous paper)”) will be described.

  As shown in FIGS. 1 and 3, the printer 1 according to the present embodiment includes a transport unit 20 and a transport path through which the transport unit 20 transports the roll paper 2 (in FIG. 3, the transport path is a roll A feed unit 10, a platen 29, and a take-up unit 90, along the paper roll shaft 18 to the roll paper take-up drive shaft 92. The head unit 30 that performs image printing by ejecting a plurality of types of ink in the printable region R on the transport path, the carriage unit 40, the cleaning unit 45, the heater unit 70 as an example of the heating unit, and the suction unit As an example, a suction unit 75, a blower unit 80 for sending wind to the roll paper 2 on the platen 29, and these units are controlled and pre-controlled. A controller 60 that controls the operation of the coater 1, and a detector group 50, a.

  The feeding unit 10 feeds the roll paper 2 to the transport unit 20. The feeding unit 10 includes a roll paper winding shaft 18 around which the roll paper 2 is wound and rotatably supported, and a relay roller 19 for winding the roll paper 2 fed from the roll paper winding shaft 18 and guiding the roll paper 2 to the transport unit 20. And have.

  The transport unit 20 transports the roll paper 2 sent by the feeding unit 10 along a preset transport path. As shown in FIG. 3, the transport unit 20 includes a relay roller 21 that is located horizontally to the right of the relay roller 19, a relay roller 22 that is located obliquely downward to the right when viewed from the relay roller 21, and the relay roller 22. 1st conveyance roller 23 located in the upper right direction as viewed from the platen 29 (upstream side in the conveyance direction) and a right side as viewed from the first conveyance roller 23 (downstream in the conveyance direction as viewed from the platen 29). The second transport roller 24, the reverse roller 25 positioned vertically downward as viewed from the second transport roller 24, the relay roller 26 positioned rightward as viewed from the reverse roller 25, and upward as viewed from the relay roller 26. And a delivery roller 27 which is positioned.

The relay roller 21 is a roller that winds the roll paper 2 sent from the relay roller 19 from the left side and loosens it downward.
The relay roller 22 is a roller that winds the roll paper 2 sent from the relay roller 21 from the left side and conveys it obliquely upward to the right.

  The first transport roller 23 includes a first drive roller 23a driven by a motor (not shown), and a first driven roller 23b arranged to face the first drive roller 23a with the roll paper 2 interposed therebetween. have. The first transport roller 23 is a roller that pulls up the roll paper 2 slacked downward and transports it to the printing region R facing the platen 29. The first transport roller 23 is configured to temporarily stop transport during a period in which image printing is performed on a portion of the roll paper 2 on the print region R. In addition, the conveyance amount of the roll paper 2 positioned on the platen 29 is adjusted by rotating the first driven roller 23b in accordance with the rotational drive of the first drive roller 23a by the drive control of the controller 60.

  As described above, the transport unit 20 has a mechanism for transporting the portion of the roll paper 2 wound between the relay rollers 21 and 22 and the first transport roller 23 by slacking it downward. The slackness of the roll paper 2 is monitored by the controller 60 based on a detection signal from a slack detection sensor (not shown). Specifically, when a portion of the roll paper 2 slackened between the relay rollers 21 and 22 and the first transport roller 23 is detected by the slack detection sensor, a tension of an appropriate magnitude is applied to the portion. Therefore, the transport unit 20 can transport the roll paper 2 in a relaxed state. On the other hand, when the portion of the roll paper 2 that has been loosened is not detected by the slack detection sensor, an excessive amount of tension is applied to the portion, so that the roll paper 2 is transported by the transport unit 20. It is temporarily stopped and the tension is adjusted to an appropriate magnitude.

  The second transport roller 24 includes a second drive roller 24a driven by a motor (not shown), and a second driven roller 24b disposed so as to face the second drive roller 24a with the roll paper 2 interposed therebetween. have. The second transport roller 24 is a roller that transports the portion of the roll paper 2 on which the image is recorded by the head unit 30 in the horizontal right direction along the support surface of the platen 29 and then transports it vertically downward. Thereby, the conveyance direction of the roll paper 2 is changed. The second driven roller 24b rotates as the second drive roller 24a is driven to rotate by the drive control of the controller 60, whereby a predetermined amount given to the portion of the roll paper 2 located on the platen 29 is obtained. Tension is adjusted.

The reversing roller 25 is a roller that wraps the roll paper 2 sent from the second conveying roller 24 from the upper left side and conveys it diagonally upward to the right.
The relay roller 26 is a roller that winds the roll paper 2 sent from the reversing roller 25 from the lower left side and conveys it upward.
The delivery roller 27 winds the roll paper 2 sent from the relay roller 26 from the lower left side and sends it to the take-up unit 90.

  As described above, the roll paper 2 moves sequentially through the rollers, whereby a transport path for transporting the roll paper 2 is formed. The roll paper 2 is intermittently conveyed along the conveyance path by the conveyance unit 20 in units of areas corresponding to the printing areas R.

  The head unit 30 is for recording an image on a portion of the roll paper 2 located in the printing region R on the transport path. That is, the head unit 30 forms an image by ejecting ink from the ink ejection nozzles onto the portion of the roll paper 2 that has been fed into the printing region R (on the platen 29) on the transport path by the transport unit 20. In the present embodiment, the head unit 30 has M heads 31.

  Each head 31 has an ink discharge nozzle row in which ink discharge nozzles are arranged in the row direction on the lower surface (that is, the nozzle surface). In the present embodiment, ink composed of a plurality of ink ejection nozzles # 1 to #N for each color such as white (W), cyan (C), magenta (M), yellow (Y), black (K), and the like. A discharge nozzle row is provided. The ink discharge nozzles # 1 to #N of each ink discharge nozzle row are linearly arranged in a cross direction that intersects the transport direction of the roll paper 2 (that is, the cross direction is the above-described row direction). . The respective ink discharge nozzle rows are arranged in parallel with a space therebetween along the transport direction.

  Each of the ink discharge nozzles # 1 to #N is provided with a piezo element (not shown) as a drive element for discharging ink droplets. When a voltage having a predetermined time width is applied between the electrodes provided at both ends of the piezoelectric element, the piezoelectric element expands according to the voltage application time and deforms the side wall of the ink flow path. As a result, the volume of the ink flow path contracts according to the expansion and contraction of the piezo element, and the ink corresponding to the contraction is ejected from the ink ejection nozzles # 1 to #N of the respective colors as ink droplets.

  Then, M such heads 31 are arranged in the intersecting direction (the row direction), thereby forming the head unit 30. Therefore, the head unit 30 has M × N ink ejection nozzles for each color.

  The carriage unit 40 is for moving the head unit 30 (head 31). The carriage unit 40 is supported so as to reciprocate in the transport direction (left and right direction) along the carriage guide rail 41 and a carriage guide rail 41 (indicated by a two-dot chain line in FIG. 3) extending in the transport direction (left and right direction). A carriage 42 and a motor (not shown). The carriage 42 in the present embodiment has four sub-carriages, and a plurality of heads 31 are provided for each sub-carriage. The carriage 42 is configured to move in the transport direction (left-right direction) together with the head unit 30 (head 31) by driving a motor (not shown). In addition, when the head unit 30 (head 31) is cleaned after image printing, the carriage 42 is integrated with the head unit 30 (head 31) along the carriage guide rail 41 on the upstream side (from the platen 29). It moves to the upstream side in the transport direction as viewed, and stops at the home position HP for cleaning (see FIG. 3).

  The cleaning unit 45 is provided at the home position HP and is for cleaning the head unit 30 (head 31). The cleaning unit 45 includes a cap (not shown), a suction pump, and the like. When the carriage 42 is positioned at the home position HP, the cap is in close contact with the lower surface (nozzle surface) of the head 31. When the suction pump operates in such a state that the cap is in close contact, the ink in the head 31 is sucked together with the thickened ink and paper dust. In this way, the clogged nozzle recovers from the non-ejection state, thereby completing the head cleaning.

  The platen 29 supports the part of the roll paper 2 located in the printable region R on the transport path and heats the part. As shown in FIG. 3, the platen 29 is provided corresponding to the printable region R on the conveyance path, and is an area along the conveyance path between the first conveyance roller 23 and the second conveyance roller 24. Is arranged. The platen 29 can heat the portion of the roll paper 2 by receiving supply of heat generated by the heater unit 70.

  The heater unit 70 is for heating the roll paper 2 and has a heater 71. The heater 71 has a nichrome wire, and the nichrome wire is arranged inside the platen 29 so as to be a fixed distance from the support surface of the platen 29. For this reason, when the heater 71 is energized, the nichrome wire itself generates heat and can conduct heat to the portion of the roll paper 2 located on the support surface of the platen 29. Since the heater 71 is configured by incorporating a nichrome wire in the entire area of the platen 29, it can conduct heat uniformly to the portion of the roll paper 2 on the platen 29. In the present embodiment, the portion of the roll paper 2 is uniformly heated so that the temperature of the portion of the roll paper 2 on the platen is 45 ° C. Thereby, the ink landed on the part of the roll paper 2 can be dried.

  The suction unit 75 is for sucking and sucking the roll paper 2 on the platen 29 onto the support surface of the platen 29. Details will be described later.

  The blower unit 80 is for sending wind to the roll paper 2 on the platen 29. The blower unit 80 includes a fan 81 and a motor (not shown) that rotates the fan 81. The fan 81 rotates to send wind to the roll paper 2 on the platen 29 and dry the ink landed on the roll paper 2. As shown in FIG. 3, a plurality of fans 81 are provided on an openable / closable cover (not shown) provided on the main body. Each fan 81 is positioned above the platen 29 when the cover is closed, and faces the support surface of the platen 29 (the roll paper 2 on the platen 29).

  The winding unit 90 is for winding the roll paper 2 (image-printed roll paper) sent by the transport unit 20. This take-up unit 90 is fed from the relay roller 91 that is rotatably supported by the relay roller 91 for winding the roll paper 2 sent from the feed roller 27 from the upper left side and conveying it to the lower right side. A roll paper take-up drive shaft 92 for taking up the roll paper 2.

  The controller 60 is a control unit for controlling the printer 1. As shown in FIG. 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 is for transmitting and receiving data between the computer 110 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. The CPU 62 controls each unit by a unit control circuit 64 according to a program stored in the memory 63.

  The detector group 50 is for monitoring the situation in the printer 1. For example, the above-described slack detection sensor, a rotary encoder attached to the conveyance roller and used for controlling the conveyance of the roll paper 2, and the like A paper detection sensor for detecting the presence or absence of the roll paper 2 to be detected, a linear encoder for detecting the position of the carriage 42 (or head 31) in the transport direction (left-right direction), and a paper edge (edge) in the width direction of the roll paper 2 ) There is a paper edge position detection sensor that detects the position.

<<< Operation Example of Printer 1 >>>
Next, focusing on a portion of the roll paper 2 located on the platen 29 (hereinafter referred to as “target portion”), various operations performed by the printer 1 with respect to the target portion will be described with reference to FIG. To do. FIG. 4 is a flowchart for explaining various operations performed by the printer 1 for each target portion of the roll paper.

  Various operations of the printer 1 are realized mainly by the controller 60. In particular, this embodiment is realized by the CPU 62 processing the program stored in the memory 63. And this program is comprised from the code | cord | chord for performing the various operation | movement demonstrated below.

The controller 60 receives a print command from the host computer 1100 via the interface unit 61 (S101).
This print command is included in the header of print data transmitted from the host computer 1100.
Then, the controller 60 analyzes the contents of various commands included in the received print data, and performs the following processing using each unit.

First, the controller 60 performs a feeding process (S102).
The feeding process is a process of feeding the roll paper 2 from the upstream side to the downstream side in the conveyance direction and positioning the roll paper 2 at a printing start position (also referred to as a cueing position) on the platen 29.

  The controller 60 drives the transport motor, rotates the transport roller 23 to transport the roll paper 2 along the transport direction, and positions the roll paper 2 at the print start position. As a result, the first target portion of the roll paper 2 is set in a stopped state on the platen 29 (in the printable recording area R).

Next, the controller 60 performs an ink ejection process on the target portion of the roll paper 2 that stops on the platen 29 (S103).
The ink ejection process is a process in which ink is intermittently ejected from the head 31 moving in the transport direction (left-right direction) to form dots on the target portion of the roll paper 2 on the platen 29.

The controller 60 drives the carriage motor to move the carriage 42 located at the home position HP along the transport direction. That is, the carriage 42 (head 31) repeats reciprocation along the transport direction according to the number of passes.
Then, the controller 60 ejects ink from the head 31 based on the print data while the carriage 42 is moving.

  As described above, the ink is ejected while the head 31 repeats reciprocation along the transport direction, whereby the ejected ink droplets land on the roll paper 2 to form a print image.

Next, the controller 60 performs a conveyance process (S104).
The conveyance process is a process in which the roll paper 2 is intermittently moved in the conveyance direction in units of frames. The controller 60 drives the conveyance motor to rotate the conveyance roller 23 and moves the roll paper 2 in the conveyance direction by a movement amount corresponding to the frame size.
By this conveyance processing, the target portion of the roll paper 2 after recording the print image (the target portion after the image is printed in S103) is released from the stopped state on the platen 29 and is transferred from the platen 29 in the conveyance direction. It moves toward the downstream side.

Next, the controller 60 performs a winding process (S105).
The winding process is a process of causing the winding unit 80 to wind the target portion of the roll paper 2 after printing. The controller 60 drives the take-up motor and rotates the roll paper take-up drive shaft 92 to take up the portion of the roll paper 2 after printing.
Thereafter, when these various operations are completed, the controller 60 moves the carriage 42 to the home position HP.

  In the following, after describing a comparative example, a series of operations of the printer 1 according to the present embodiment will be specifically described.

<About Comparative Example>
A comparative example will be described with reference to FIGS. 5A to 5F. 5A to 5F are diagrams illustrating a series of operations in the comparative example.

  First, after intermittent conveyance by the conveyance unit 20, the state shown in FIG. 5A is obtained. The length of the target portion in the transport direction is the same as the length L in the transport direction of the platen 29 (hereinafter referred to as “platen length L”).

  Next, printing is performed on the target portion of the roll paper 2 stopped on the platen 29 by ink ejection by the head unit 30. That is, as shown in FIG. 5B, an image is formed on a portion located in the print region among the target portions of the roll paper 2. The print area is an area where an image is printed at the target portion of the roll paper 2. In the comparative example, two print images are formed in the print area. The printing area is located closer to the downstream side than the center of the platen 29 in the transport direction. That is, the center of the printing area is located downstream of the center of the platen 29 in the transport direction. This is because the print start position of the print image is set in the print data so as to be printed right-justified. Further, since heat is transmitted to the portion located in the printing area of the roll paper 2 by the heated platen 29, the ink that has landed on the printing area can be dried. On the other hand, the region other than the print region in the target portion of the roll paper 2 is a non-print region where no print image is formed. The non-printing area is located closer to the upstream side than the center of the platen 29 in the conveying direction because the printing area is located on the downstream side in the conveying direction. Since the non-printing area is located on the platen, heat is transmitted to the part located in the non-printing area of the roll paper 2 by the heated platen 29. The non-printing region is dried by receiving heat from the platen 29 and is in a contracted state.

  Thus, after printing, a print area and a non-print area are formed in the target part of the roll paper 2. During this printing, since the platen 29 is heated by the heater unit 70, the printing area and the non-printing area are heated by the platen 29. Further, as shown in FIG. 5B, the length corresponding to the platen length L is obtained by adding up the length A in the transport direction of the print area and the length B in the transport direction of the non-print area. Thereafter, the length A in the conveyance direction of the printing area is a frame unit, and the roll paper 2 after printing is intermittently conveyed for each frame.

  Next, when the roll paper 2 after printing is intermittently conveyed by the conveyance unit 20 in units of frames (length A in the conveyance direction of the printing area), as shown in FIG. 5C, a new target portion of the roll paper 2 is obtained. Stops on the platen 29. The new target portion of the roll paper 2 includes a part of the non-printing area shown in FIG. 5B (the hatched portion in FIG. 5C; hereinafter referred to as “previous non-printing area”). That is, since the previous non-printing area is positioned again on the platen 29 after the conveyance, the new target part of the roll paper 2 includes a part already heated by the platen 29 (previous non-printing area). In addition, a portion that has not yet been heated (a region other than the previous non-printing region) is included.

  Next, printing is performed on a new target portion of the roll paper 2 stopped on the platen 29 by ink ejection by the head unit 30. In the comparative example, as illustrated in FIG. 5D, two new print images are formed in a part located in the print region among the new target parts of the roll paper 2. Since the print area including the two new print images is located closer to the downstream side than the center of the platen 29 in the transport direction, as in FIG. 5B, the two new print images have already been formed. The two printed images are arranged at a predetermined interval. Further, heat is transmitted to a portion located in the printing area of the roll paper 2 through the heated platen 29. Therefore, the ink that has landed on the print area can be dried. Note that the previous non-printing area (shaded area in FIG. 5D) is again positioned on the platen 29, and is therefore heated again by the platen 29. On the other hand, the non-printing area in the new target part of the roll paper 2 is located upstream of the center of the platen 29 in the conveyance direction because the printing area is located downstream in the conveyance direction. Since the non-printing area is located on the platen, heat is also transmitted to the part located in the non-printing area of the roll paper 2 via the heated platen 29.

  As described above, after printing, a print area and a non-print area are arranged in a new target portion of the roll paper 2. During this printing, since the platen 29 is heated by the heater unit 70, the printing area and the non-printing area are heated by the platen 29. In addition, since the previous non-printing area (the hatched portion in FIG. 5D) is partly included in this printing area, the previous non-printing area is heated again on the platen, and excessively It is in a dry state.

  Thereafter, as described above, as shown in FIGS. 5E and 5F, the print operation by the head unit 30 and the transport operation by the transport unit 20 are repeatedly performed, and a plurality of print images continuous at a constant interval are formed. It is formed on the roll paper 2.

  As described above, as shown in FIG. 5B, when a plurality of print images are formed in the print area by printing on the target portion of the roll paper 2, the length A in the transport direction of the print area is greater than the platen length L. May be shorter. During this printing, the printing area and the area other than the printing area (non-printing area) are heated by the platen 29. Thereafter, as shown in FIG. 5C, when intermittent conveyance is performed for each length A in the conveyance direction of the printing area (for each frame), the previous non-printing area (the hatched portion in FIG. 5D) is printed as shown in FIG. 5D. It will be included in part of the area. Therefore, when a print image is formed in a part located in the printing area of the roll paper 2, the part that has already been heated by the platen 29 (previous non-printing area) and the part that has not been heated yet (previous non-printing area) A print image is formed in a print area other than (1). Since the already heated portion (previous non-printing region) is already dry before printing, when the ink ejected by the head 31 lands, the landed ink soaks more. . For this reason, the roll paper 2 is greatly expanded due to the absorption of a large amount of ink, and the landing position of the ink is largely shifted, so that the print image quality is deteriorated. As a result, there is a difference in print image quality between the case where the print image is formed on the heated portion of the roll paper 2 and the case where the print image is formed on the unheated portion.

<About this embodiment>
Next, a series of operations in the present embodiment will be described with reference to FIGS. 6A to 6F. 6A to 6F are diagrams for describing a series of operations in the present embodiment.

  First, after intermittent conveyance by the conveyance unit 20, the state shown in FIG. 6A is obtained. The length of the target portion in the transport direction is the same as the platen length L.

  Next, printing is performed on the target portion of the roll paper 2 stopped on the platen 29 by ink ejection by the head unit 30. That is, as shown in FIG. 6B, an image is formed on a portion located in the print region among the target portions of the roll paper 2. In the present embodiment, two print images are formed in the print area. Unlike the comparative example, the printing area is located closer to the upstream side than the center of the platen 29 in the transport direction (in the present embodiment, it is located closer to the most upstream side). That is, the center of the printing area is located upstream of the center of the platen 29 in the transport direction. This is because the print data is set so that the print start position of the print image is printed left justified. Further, heat is transmitted to a portion located in the printing area of the roll paper 2 through the heated platen 29. Therefore, the ink that has landed on the print area can be dried. On the other hand, the region other than the print region in the target portion of the roll paper 2 is a non-print region where no print image is formed. The non-printing area is located closer to the downstream side than the center of the platen 29 in the conveying direction because the printing area is located on the upstream side in the conveying direction.

  Thus, after printing, a print area and a non-print area are formed in the target part of the roll paper 2. During this printing, since the platen 29 is heated by the heater unit 70, the printing area and the non-printing area are heated by the platen 29. Also, as shown in FIG. 6B, the length corresponding to the platen length L is the sum of the length A in the transport direction of the print area and the length B in the transport direction of the non-print area. Further, the length A in the transport direction of the printing area is longer than half of the platen length L. Thereafter, the length A in the conveyance direction of the printing area is a frame unit, and the roll paper 2 after printing is intermittently conveyed for each frame.

  Next, when the roll paper 2 after printing is intermittently conveyed by the conveyance unit 20 in units of frames (length A in the conveyance direction of the printing area), as shown in FIG. 6C, a new target portion of the roll paper 2 is obtained. Stops on the platen 29. The new target portion of the roll paper 2 includes a part of the printing area shown in FIG. 6B (shaded part in FIG. 6C; hereinafter referred to as “part of the previous printing area”). That is, since a part of the preprinted area is again positioned on the platen 29 after the conveyance, a new target part of the roll paper 2 includes a part already heated by the platen 29 (part of the preprinted area). ) And a portion that has not yet been heated (a region other than a part of the preprinted region).

  Next, printing is performed on a new target portion of the roll paper 2 stopped on the platen 29 by ink ejection by the head unit 30. In the present embodiment, as shown in FIG. 6D, two new print images are formed in a part located in the print region among the new target parts of the roll paper 2. Since the print area including the two new print images is located on the upstream side of the center of the platen 29 in the transport direction as in FIG. 6B, the two new print images have already been formed. The two printed images are arranged at a predetermined interval. Further, since heat is transmitted to the portion located in the printing area of the roll paper 2 through the heated platen 29, the ink that has landed on the printing area can be dried. On the other hand, a part of the preprinted area in the new target portion of the roll paper 2 (shaded area in FIG. 6D) is closer to the downstream side than the center of the platen 29 in the transport direction because the print area is located on the upstream side in the transport direction. Will be located. A part of this preprinted area is again located on the platen 29 and is heated again by the platen 29.

  In this way, after printing, a part of the print area and the pre-print area are arranged in a new target part of the roll paper 2. During this printing, since the platen 29 is heated by the heater unit 70, a part of the print area and the preprint area is heated by the platen 29. A part of the preprinted area is heated again on the platen, but as shown in FIG. 6D, a new print image is not formed. Therefore, the re-heating of the platen 29 does not affect the print image already formed in a part of the preprint area so as to deteriorate the image quality.

  Thereafter, as described above, as shown in FIGS. 6E and 6F, the print operation by the head unit 30 and the transport operation by the transport unit 20 are repeatedly performed, and a plurality of print images continuous at a constant interval are formed. It is formed on the roll paper 2.

  As described above, as shown in FIG. 6B, when a plurality of print images are formed in the print region by printing on the target portion of the roll paper 2, the length A in the transport direction of the print region is the platen length L. May be shorter. During this printing, the printing area and the area other than the printing area (non-printing area) are heated by the platen 29. Thereafter, as shown in FIG. 6C, when intermittent conveyance is performed for each length A in the conveyance direction of the printing area (for each frame), unlike the comparative example, a part of the previous printing area (the hatched portion in FIG. 6C) is again generated. It is located on the platen 29 and the next print area is located on the platen 29. Then, as shown in FIG. 6D, when a print image is formed in a part located in the print area of the roll paper 2, unlike the comparative example, in the part already heated by the platen 29 (part of the preprint area). Instead, a print image is always formed in a portion that is not heated (a region other than a part of the previous print region). Since the unheated portion is in a state where moisture is appropriately retained before printing, even if the ink ejected by the head 31 is landed, the roll paper 2 does not greatly expand, so that the print image quality Can be prevented.

<<< Effectiveness of Printer 1 According to the Present Embodiment >>>
As described above, the printer 1 according to the present embodiment supports the roll paper 2 and heats the platen 29, and the roll paper 2 supported and heated by the platen 29 is positioned within the printing region. A head unit 30 (head 31) for printing an image on a portion to be transported, and a transport unit for intermittently transporting the roll paper 2 for each length A (for each frame) in the transport direction of the print area along the transport direction. 20, and the length A of the printing area in the transport direction is shorter than the length of the platen 29 in the transport direction (platen length L), and the length (platen length L) is It is longer than half, and the printing area is located closer to the upstream side than the center of the platen 29 in the transport direction.

  In the comparative example, printing is performed so that the printing region is located closer to the downstream side than the center of the platen 29 in the transport direction (printing is performed with right justification). When printing is performed with right justification in this way, the length A in the transport direction of the print region may be shorter than the platen length L (see FIG. 5B). During this printing, the printing area and the area other than the printing area (non-printing area) are heated by the platen 29. Thereafter, if intermittent conveyance is performed for each length A in the conveyance direction of the printing area (for each frame), a non-printing area is included in a part of the next printing area (see FIG. 5C). Then, when the next print image is formed in the part located in the printing area of the roll paper 2, the part already heated by the platen 29 (non-printing area) and the part not heated yet (other than the non-printing area) ), The next print image is formed (see FIG. 5D). Since the heated portion (non-printing region) is in an excessively dried state before printing, when the ink ejected by the head 31 lands, the landed ink soaks more. For this reason, the roll paper 2 is greatly expanded due to the absorption of a large amount of ink, and the landing position of the ink is largely shifted, so that the print image quality is deteriorated.

  On the other hand, in the present embodiment, printing is performed so that the printing area is positioned closer to the upstream side than the center of the platen 29 in the transport direction (printing is performed with left justification). Even when printing is performed with left justification in this way, the length A in the transport direction of the print region may be shorter than the platen length L (see FIG. 6B). During this printing, the printing area is heated by the platen 29. Thereafter, if intermittent conveyance is performed for each length A in the conveyance direction of the print area (for each frame), a part of the previous print area (the hatched portion in FIG. 6C) is not included in the subsequent print area (see FIG. 6C). ). Therefore, even if a print image is formed in a portion located in the print area of the roll paper 2, unlike the comparative example, a print image is always formed in a portion that is not heated (see FIG. 6D). . Since the unheated portion is in a state where water is appropriately retained before printing, the roll paper 2 does not greatly expand even when the ink ejected by the head 31 lands, and the printing image quality is improved. Deterioration can be suppressed.

  As described above, in the above-described embodiment, as illustrated in FIGS. 6A to 6F, the case where the printing region is located closer to the most upstream side than the center of the platen 29 in the transport direction has been described as an example. However, the present invention is not limited to this, and the print area may be located upstream of the center of the platen 29 in the transport direction, that is, the center of the print area may be located upstream of the center of the platen 29 in the transport direction. That's fine.

<<< About the adsorption unit 75 >>>
Here, the structural example of the adsorption | suction unit 75 concerning this embodiment is demonstrated using FIG. FIG. 7 is a schematic diagram showing the configuration of the suction unit 75.

  The suction unit 75 of the present embodiment is configured such that the suction force for sucking the roll paper 2 on the platen 29 can be varied. Hereinafter, specific examples will be described.

  The suction unit 70 is for sucking and sucking the roll paper 2 on the platen 29 onto the support surface of the platen 29, and includes a negative pressure chamber 76, a plurality of suction fans 77, and the like. A negative pressure chamber 76 is provided below the platen 29. The negative pressure chamber 76 is divided into a plurality of individual chambers, and suction fans 77 are attached to the bottom surfaces 76a of the individual chambers. Each individual chamber of the negative pressure chamber 76 is provided in association with each area that partitions the platen 29. Then, the controller 60 controls the number of rotations of each suction fan 77, whereby a desired negative pressure can be set for each individual chamber of the negative pressure chamber 76. Therefore, when the printing area of the roll paper 2 supported by the platen 29 is resized, the suction force is determined to be the size of the area of the platen 29 to be changed, and the suction of each individual chamber corresponding to that area is determined. The rotation speed of the fan 77 can be set. For example, the controller 60 causes the individual chamber of the negative pressure chamber 76 to have a desired high negative pressure (desired high adsorption force) by operating the suction fan 77 at a rotation speed of 100%, or sets the suction fan 77 to 50%. By operating at the rotation speed, the individual chamber of the negative pressure chamber 76 can be set to a desired low negative pressure (a desired low adsorption force). By doing so, the suction unit 75 can change the strength of the suction force for each area of the platen 29.

  Here, in the above embodiment, a part of the preprint area of the roll paper 2 (the hatched portion in FIG. 6D) is located twice on the platen (FIGS. 6B and 6D). It will be heated twice in succession. When an image printed on a part of the preprinted area of the roll paper 2 (shaded area in FIG. 6D) is formed with a large amount of ink, so-called cockling (bending of the roll paper 2) occurs during the second heating. May occur. When cockling occurs, the landing position of the ink droplets shifts, degrading the print image quality. Therefore, for example, the area on the platen 29 corresponding to a part of the preprint area of the roll paper 2 (the hatched portion in FIG. 6D) is caused by the suction unit 75 rather than the area of the platen corresponding to the print area of the roll paper 2. You may set so that adsorption power may become strong. As a result, a part of the preprinted area of the roll paper 2 (the hatched portion in FIG. 6D) is strongly adsorbed to the support surface of the platen 29, and the deflection of the roll paper 2 is held in a flat state. 2 can be suppressed.

=== Other Embodiments ===
Although the present embodiment is mainly described with respect to a printing apparatus, disclosure of a printing method and the like is also included. Further, the present embodiment is intended to facilitate 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.

<Printing device>
In the above embodiment, an ink jet printer has been described as an example of a printing apparatus. However, the present invention is not limited to this. For example, a printing apparatus that discharges liquid other than ink may be used. The present invention can be used in various printing apparatuses including a liquid ejecting head that discharges a minute amount of liquid droplets. In addition, a droplet means the state of the liquid discharged from the said printing apparatus, and shall include what pulls a tail in granular shape, tear shape, and thread shape. The liquid here may be any material that can be ejected by the printing apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And a liquid as one state of a substance, as well as a material in which particles of a functional material made of a solid such as a pigment or metal particles are dissolved, dispersed or mixed in a solvent. Further, representative examples of the liquid include ink and liquid crystal as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks. Specific examples of printing apparatuses include, for example, liquids that are dispersed or dissolved in materials such as liquid crystal displays, EL (electroluminescence) displays, surface-emitting displays, and electrode materials and color materials used in the manufacture of color filters. It may be a printing apparatus that discharges biological organic materials used in biochip manufacturing, a printing apparatus that is used as a precision pipette and discharges a sample liquid, a textile printing apparatus, a microdispenser, or the like. In addition, transparent resin liquids such as UV curable resins are used to form micro hemispherical lenses (optical lenses) that are used in optical devices, such as printers that eject lubricant oil to precision machines such as watches and cameras. You may employ | adopt the printing apparatus which discharges etching liquid, such as an acid or an alkali, in order to etch the printing apparatus discharged on a board | substrate, a board | substrate. The present invention can be applied to any one of these printing apparatuses.

DESCRIPTION OF SYMBOLS 1 Printing apparatus 2 Roll paper 10 Feeding unit 18 Roll paper winding shaft 19 Relay roller 20 Transport unit 21 Relay roller 22 Relay roller 23 First transport roller 24 Second transport roller 25 Inversion roller 26 Relay roller 27 Feeding roller 29 Platen 30 Head unit 31 Head 40 Carriage unit 41 Guide rail 42 Carriage 45 Cleaning unit 50 Detector group 60 Controller 70 Heater unit 71 Heater 75 Adsorption unit 76 Suction fan 80 Blower unit 81 Fan 90 Winding unit 91 Relay roller 92 Roll paper winding drive shaft 1000 Printing System 1100 Host computer 1200 Display device 1300 Input device 1400 Recording / playback device

Claims (3)

A platen for supporting and heating the medium;
A head that prints an image on a portion of the heated medium that is supported by the platen and that is located within the print area;
A transport unit that intermittently transports the medium for each length in the transport direction of the print region along the transport direction;
The length of the print area in the transport direction is shorter than the length of the platen in the transport direction, and longer than half of the length,
The printing apparatus, wherein the printing region is located upstream of the center of the platen in the transport direction. The printing apparatus according to claim 1,
An adsorbing part for adsorbing the medium supported by the platen to the platen;
Other than the print area of the heated medium supported and supported by the platen, rather than the adsorbing force that the adsorbing part adsorbs the portion of the heated medium located in the print area supported by the platen. A controller that controls a portion located in the region of the suction portion so that the suction force that the suction portion sucks is larger,
A printing apparatus comprising: Printing an image with a head on a portion of the heated medium supported and heated by a platen that supports and heats the medium and is located within the print area;
Intermittently transporting the medium by a transport unit for each length in the transport direction of the print area along the transport direction,
The length of the print area in the transport direction is shorter than the length of the platen in the transport direction, and longer than half of the length,
The printing method according to claim 1, wherein the printing area is located upstream of the center of the platen in the transport direction.