JP6010896B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  2. Description of the Related Art As an image forming apparatus, an ink jet printer that forms an image on a printing medium by ejecting ink that is a kind of liquid onto a printing medium (for example, paper) is known. In the printer, the printing process may be repeatedly performed on the same print area of the print medium. For example, after an image is formed on a printing medium, an auxiliary ink (for example, clear ink) is applied on the image to coat (overcoat) the image surface.

JP 2000-094726 A

  Characteristics such as the ease of peeling off of the coating, glossiness, and fixability vary depending on the state of the ground at the position where the auxiliary ink lands. In other words, the optimum amount (discharge amount) of auxiliary ink varies depending on the state of the background. However, conventionally, auxiliary ink has been ejected under the same conditions regardless of the state of the ground. For this reason, for example, there is a possibility that auxiliary ink may be used unnecessarily by unnecessarily discharging auxiliary ink, or the amount of auxiliary ink discharged may be insufficient and gloss may not be obtained or may be peeled off. There was a fear.

  Therefore, an object of the present invention is to optimize the discharge conditions of auxiliary ink.

  A main invention for achieving the above object includes a first discharge unit capable of discharging color ink for forming an image, a second discharge unit capable of discharging auxiliary ink for assisting the image, a printing medium, and Parameters set for each of the color inks, the storage unit storing at least one parameter of ease of peeling, glossiness, and ink fixability, and discharging the color ink from the first discharge unit A control unit configured to discharge the auxiliary ink from the second discharge unit to the predetermined area of the print medium after the image is formed on the print medium with a discharge amount or the number of discharges based on the parameter; And an image forming apparatus.

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

1 is a schematic sectional view of a printer 1. 2 is a block diagram of the printer 1. FIG. 4 is an explanatory diagram of a configuration of a head 31. FIG. 4 is a cross-sectional view for explaining an internal structure of a head 31. FIG. It is the schematic diagram which showed the raster line formed in each pass in the case of printing by 4 passes. It is an explanatory schematic diagram for explaining the movement of the head. FIG. 8 is an explanatory diagram of processing by a printer driver. It is a figure which shows the printing data for 1 frame. It is a schematic diagram which shows the process of printing. It is a figure which shows the parameter for defining the printing condition of overprint (OP). It is a figure which shows the correspondence of the tabulation result of a parameter, and the printing condition of OP. It is a conceptual diagram which shows the cross-sectional structure at the time of performing OP. It is the figure which showed the total value of the parameter in each area for every characteristic. It is a figure which shows the calculation result of the discharge conditions of the clear ink of each area. It is a conceptual diagram which shows the state which performed OP in 1st Embodiment. It is a conceptual diagram which shows the state which performed OP in 2nd Embodiment.

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

Parameters set for each of the first ejection unit capable of ejecting color ink for forming an image, the second ejection unit capable of ejecting auxiliary ink for assisting the image, the printing medium, and the color ink. And after forming the image on the printing medium by ejecting the color ink from the first ejection unit and storing a storage unit storing at least one parameter of ease of peeling, glossiness, and ink fixability An image forming apparatus comprising: a control unit that discharges the auxiliary ink from the second discharge unit to a predetermined region of the printing medium with a discharge amount or a number of discharges based on the parameter. Becomes clear.
According to such an image forming apparatus, it is possible to optimize the discharge conditions of the auxiliary ink.

The image forming apparatus may further include a third ejection unit capable of ejecting a background color ink that forms a background image serving as a background of the image, and the parameters include the printing medium, the color ink, and the background. The color ink is set for each of the color inks, and the control unit causes the color ink and the background color ink to be ejected from the first ejection unit and the third ejection unit, respectively. After the formation, it is preferable that the auxiliary ink is ejected from the second ejection unit to a predetermined area of the printing medium with a ejection amount or ejection number based on the parameter.
According to such an image forming apparatus, it is possible to optimize the discharge conditions of the auxiliary ink even when a background image is formed.

In this image forming apparatus, the control unit causes the auxiliary ink to be ejected from the second ejection unit based on the sum of the parameters for the printing medium, the color ink, and the background color ink. Also good.
According to such an image forming apparatus, it is possible to optimize the discharge conditions of the auxiliary ink.

In this image forming apparatus, the control unit causes the auxiliary ink to be ejected from the second ejection unit based on a product of the parameters for the printing medium, the color ink, and the background color ink. Also good.
According to such an image forming apparatus, it is possible to optimize the discharge conditions of the auxiliary ink.

The image forming apparatus includes a plurality of the first ejection units corresponding to the color inks of a plurality of colors, and the control unit includes the parameter of the printing medium in the predetermined region, and the plurality of colors of the parameters. It is desirable that the auxiliary ink is ejected from the second ejection unit based on the product of the sum of the parameters of the color ink and the parameter of the background color ink.
According to such an image forming apparatus, it is possible to optimize the discharge conditions of the auxiliary ink.

In such an image forming apparatus, the control unit may move the predetermined area from the second discharge unit with the maximum discharge amount or the maximum number of discharges required for the ease of peeling, the glossiness, and the ink fixing property. The auxiliary ink may be discharged.
According to such an image forming apparatus, it is possible to discharge auxiliary ink to a predetermined region under a condition in which any of the three characteristics (ease of peeling, glossiness, and ink fixing property) is optimized.

In such an image forming apparatus, the control unit controls the second discharge unit so as not to exceed the discharge amount calculated for the gloss and the number of discharges in a print mode for printing printed matter with limited gloss. It is desirable to discharge the auxiliary ink.
According to such an image forming apparatus, it is possible to set optimal auxiliary ink ejection conditions within a range where gloss does not exceed a predetermined value.

  In the following embodiments, an ink jet printer (hereinafter also referred to as printer 1) will be described as an example.

=== First Embodiment ===
<Regarding the configuration example of the printer 1>
A configuration example of the printer 1 will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic sectional view of the printer 1. FIG. 2 is a block diagram 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. 1 is used as a reference. In addition, the “front-rear direction” refers to a direction orthogonal to the paper surface in FIG.
In the present embodiment, a description will be given using a roll paper 2 (continuous paper) as a medium (print medium) on which the printer 1 records an image.

  As shown in FIGS. 1 and 2, the printer 1 according to this embodiment includes a conveyance unit 20, a feeding unit 10, a platen 29, and a conveyance path along which the conveyance unit 20 conveys the roll paper 2. And a winding unit 80. Furthermore, the printer 1 includes a head unit 30, a carriage unit 40, a cleaning unit 70, a nozzle inspection unit 90, a controller 60 that controls these units and the like to control the operation as the printer 1, a detector group 50, ,have.

  The feeding unit 10 feeds the roll paper 2 to the transport unit 20. The feeding unit 10 includes a winding shaft 18 around which the roll paper 2 is wound and rotatably supported, a relay roller 19 for winding the roll paper 2 fed from the winding shaft 18 and guiding the roll paper 2 to the transport unit 20; 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. 1, the transport unit 20 includes a relay roller 21 that is positioned horizontally to the right of the relay roller 19, a relay roller 22 that is positioned obliquely downward to the right when viewed from the relay roller 21, and the relay roller 22. The first transport roller 23 located on the upper right side when viewed from the upstream side (upstream side when viewed from the platen 29 in the direction in which the roll paper 2 is transported), and the right side (the roll paper 2 is viewed from the first transport roller 23). In the direction of conveyance, the second conveyance roller 24 located on the downstream side as viewed from the platen 29, the reverse roller 25 positioned vertically downward as viewed from the second conveyance roller 24, and the right side as viewed from the reverse roller 25. And a delivery roller 27 located above the relay roller 26 as viewed from the relay roller 26.

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 formation is performed on a portion of the roll paper 2 on the print region R (that is, as described later, the head is By ejecting ink to the corresponding portion of the roll paper 2 that is stopped while moving in the left-right direction and the front-rear direction, an image for one page is formed on the portion). In addition, when the first driven roller 23b rotates as the first drive roller 23a rotates by the drive control of the controller 60, the transport amount of the roll paper 2 positioned on the platen 29 (the length of the portion of the roll paper) Is adjusted).

  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, and therefore the transport of the roll paper 2 by the transport unit 20 is temporarily performed. And the tension is adjusted to an appropriate level.

  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 has been formed 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 feed roller 27 is configured to wind the roll paper 2 sent from the relay roller 26 from the lower left side and send it to the take-up unit 80.

  The platen 29 supports the part of the roll paper 2 located in the printing region R on the conveyance path and heats the part. As shown in FIG. 1, the platen 29 is provided in correspondence with the printing region R on the conveyance path, and in a region along the conveyance path between the first conveyance roller 23 and the second conveyance roller 24. Has been placed.

  As described above, the roll paper 2 moves sequentially through the rollers, whereby a transport path for transporting the roll paper 2 is formed. Note that the roll paper 2 is intermittently conveyed along the conveyance path in units of areas corresponding to the print area R by the conveyance unit 20 (that is, one page worth of the roll paper 2 on the print area R). Every time an image is formed is intermittently conveyed).

The head unit 30 is for ejecting ink as an example of a liquid onto a portion of the roll paper 2 that has been fed into the printing region R on the transport path (on the platen 29) by the transport unit 20. The head unit 30 has a head 31 in which a plurality of nozzles that eject ink are formed.
Details of the configuration of the head 31 will be described later.

  The carriage unit 40 is for moving the head 31. The carriage unit 40 is supported by a carriage guide rail 41 (indicated by a two-dot chain line in FIG. 1) extending in the transport direction (left-right direction) and reciprocally movable along the carriage guide rail 41 in the transport direction (left-right direction). A carriage 42 and a motor (not shown).

  The carriage 42 is configured to move in the transport direction (left-right direction) together with the head 31 by driving a motor (not shown). The carriage 42 is provided with a head guide rail (not shown) extending in the row direction (front-rear direction). The head 31 is driven in the row direction (front-rear direction) along the head guide rail by driving the motor. Configured to move to.

  The cleaning unit 70 is for cleaning the head 31. This cleaning unit is provided at a home position (hereinafter referred to as HP, see FIG. 1), and has a cap, a suction pump (both not shown), and the like. When the head 31 (carriage 42) moves in the transport direction (left-right direction) and is positioned on the HP, a cap (not shown) comes into 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. Further, when the printer 1 does not perform printing (when the carriage 42 is positioned at HP), the cap rises and comes into close contact with the lower surface of the head 31. This suppresses ink evaporation from the nozzles (in other words, ink drying). In other words, the cap functions as a lid that seals the lower surface (nozzle surface) of the head 31 during printing suspension and suppresses ink evaporation.

  The winding unit 80 is for winding the roll paper 2 (image-formed roll paper) sent by the transport unit 20. This take-up unit 80 is fed from the relay roller 81 that is rotatably supported and a relay roller 81 for winding the roll paper 2 sent from the feed roller 27 from the upper left side and conveying it obliquely downward to the right. And a take-up drive shaft 82 for taking up the roll paper 2.

  The controller 60 (corresponding to a control unit) is a control unit for controlling the printer 1. As shown in FIG. 2, 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 host computer 110 as an external device and the printer 1. The CPU 62 is an arithmetic processing unit for controlling the entire printer 1. The memory 63 (corresponding to a storage unit) is for securing an area for storing a program of the CPU 62, a work area, and the like. The memory 63 temporarily stores print data received from the host computer 110 for each ink color. Further, the memory 63 stores parameters and the like (to be described later) for setting clear ink ejection conditions. 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 detector group 50 is attached to a transport roller and used for control such as transport of the roll paper 2. And a linear encoder for detecting the position of the carriage 42 (or head 31) in the transport direction (left-right direction).

<About the configuration of the head>
FIG. 3 is an explanatory diagram of the configuration of the head 31.
The head 31 has a nozzle row in which nozzles are arranged in the row direction on the lower surface thereof. In the present embodiment, a plurality of nozzles # 1 to #n (for example, for each color of yellow (Y), magenta (M), cyan (C), black (K), white (W), and clear (CL) (for example, 180). These nozzle rows are called yellow nozzle row Y, magenta nozzle row M, cyan nozzle row C, black nozzle row K, white nozzle row W, and clear nozzle row CL, respectively.

  The nozzles # 1 to #n in each nozzle row are linearly arranged in a crossing direction that intersects the transport direction of the roll paper 2 (that is, the crossing direction is the above-described row direction). Each nozzle row is arranged in parallel with a space between each other along the transport direction.

  FIG. 4 is a cross-sectional view for explaining an example of the internal structure of the head 31. In the drawing, a cross section of a portion corresponding to two nozzles adjacent in the transport direction is shown. The head 31 includes a drive unit 32, a case 33 for housing the drive unit 32, and a flow path unit 34 attached to the case 33.

  The drive unit 32 includes a piezo element group including a plurality of piezo elements 321, a fixed plate 323 to which the piezo element group is fixed, and a flexible cable 324 for supplying power to each piezo element 321. Each piezo element 321 is attached to the fixed plate 323 in a so-called cantilever state. The fixed plate 323 is a plate-like member having rigidity capable of receiving a reaction force from the piezo element 321. The flexible cable 324 is a flexible sheet-like wiring board, and is electrically connected to the piezo element 321 on the side surface of the fixed end opposite to the fixed plate 323. On the surface of the flexible cable 324, a head controller HC, which is a control IC for controlling driving of the piezo element 321 and the like, is mounted.

  The case 33 has a rectangular parallelepiped block-like outer shape having a storage empty portion 331 in which the drive unit 32 can be stored. The flow path unit 34 is joined to the front end surface of the case 33. The housing empty portion 331 has a size that allows the drive unit 32 to be fitted exactly. The case 33 is also formed with an ink supply pipe 332 for supplying ink from a corresponding ink cartridge (not shown) to the flow path unit 34.

  The flow path unit 34 includes a flow path forming substrate 35, a nozzle plate 36, and an elastic plate 37. The flow path forming substrate 35 is laminated and integrated so that the flow path forming substrate 35 is sandwiched between the nozzle plate 36 and the elastic plate 37. Configured. The nozzle plate 36 is a thin plate made of stainless steel on which nozzles (Nz) are formed.

  In the flow path forming substrate 35, a plurality of empty portions to be the pressure chambers 351 and the ink supply ports 352 are formed corresponding to the respective nozzles Nz. The reservoir 353 is a liquid storage chamber for supplying the ink stored in the ink cartridge to each pressure chamber 351 and communicates with the other end of the corresponding pressure chamber 351 through the ink supply port 352. The ink supplied from the ink cartridge is introduced into the reservoir 353 through the ink supply pipe 332.

  The drive unit 32 is inserted into the housing empty portion 331 with the free end portion of the piezo element 321 facing the flow path unit 34, and the distal end surface of the free end portion is bonded to the corresponding island portion 373. Further, the back surface of the fixed plate 323 is bonded to the inner wall surface of the case 33 that partitions the housing empty portion 331. When a drive signal is supplied to the piezo element 321 via the flexible cable 324 in this stored state, the piezo element 321 expands and contracts to expand and contract the volume of the pressure chamber 351. Due to such a change in the volume of the pressure chamber 351, pressure fluctuation occurs in the ink in the pressure chamber 351. Then, ink droplets can be ejected from the corresponding nozzles Nz by utilizing the variation in the ink pressure.

<About ink>
In a printer, “subtractive color mixture” is used to express various colors. The primary colors of the subtractive color mixture are chromatic colors of cyan (C), magenta (M), and yellow (Y). Cyan (C) absorbs red (R) and reflects green (G) and blue (B). Magenta (M) absorbs green (G) and reflects red (R) and blue (B). Yellow (Y) absorbs blue (B) and reflects red (R) and green (G). In other words, cyan ink, magenta ink, and yellow ink represent a visually recognized image by adjusting the absorption amounts of the three primary colors RGB of light. In this embodiment, when forming an image, black (K) is used in addition to cyan (C), magenta (M), and yellow (Y). The reason why black ink is used is that strong black (deep black) cannot be expressed even if inks of three colors of CMY are mixed. In the following description, these four color (CMYK) inks that form an image are also referred to as color inks. The nozzle capable of discharging color ink corresponds to the first discharge unit. An image may be formed with any one of CMYK (at least one color), or in addition to the above four colors (CMYK), light cyan (light cyan, LC), light magenta (light magenta) , LM), green (G), orange (Or), and other color inks may be used to form an image.

  In this embodiment, the white ink (corresponding to the background color ink) is a white ink used to form a white background image as the background of the image (hereinafter, the white ink is also referred to as the white ink). Say). White ink uses a pigment such as titanium oxide as a colorant. In the present embodiment, “white” is not limited to white in the strict sense that is the surface color of an object that reflects 100% of all wavelengths of visible light. It shall include a color called white. The nozzle capable of discharging white ink corresponds to the third discharge unit.

  The clear ink is a colorless and transparent ink. In this embodiment, the clear ink is used to improve the gloss and weather resistance of the printed material by coating the surface of the image. In the following description, coating with clear ink is also referred to as OP (overprint). The nozzle that can eject clear ink corresponds to the second ejection unit.

<Operation example of printer 1>
As described above, the printer 1 according to the present embodiment is provided with the head 31 having a nozzle row in which nozzles are arranged in the row direction (front-rear direction). Then, the controller 60 ejects ink from the nozzles while moving the head 31 in the transport direction (left-right direction), and forms a raster line along the transport direction (left-right direction). One page of image recording is performed on the portion of the roll paper 2.

Here, the controller 60 according to the present embodiment executes printing of a plurality of passes (two passes, four passes, etc.). That is, in order to increase the resolution of the image in the column direction, printing is performed by changing the position of the head 31 in the column direction little by little for each pass. In this embodiment, four-pass printing is executed. As an image forming method, for example, known interlace (microweave) printing is executed.
This will be described more specifically with reference to FIG. FIG. 5 is a schematic diagram showing raster lines formed in each pass in a case of printing in 4 passes.

  A nozzle row (nozzles) of the head 31 is shown on the left side of FIG. 5 and a raster line is formed by ejecting ink from the nozzles while the head 31 (nozzle row) moves in the transport direction. . The position in the row direction of the head 31 (nozzle row) shown in the figure is the position in the first pass, and if the head 31 (nozzle row) moves in the transport direction while maintaining this position, one pass The printing of the eyes is executed, and the five raster lines shown in the figure (raster line L1 written with pass 1 at the right end) are formed.

  Next, when the head 31 (nozzle row) moves in the row direction, and the head 31 (nozzle row) moves in the transport direction while maintaining the moved position, the second pass printing is executed, and FIG. The four raster lines (raster line L2 written with path 2 on the right end) are formed. Since interlace (microweave) printing is employed, the raster line L2 adjacent to the raster line L1 is formed by ink ejected from a nozzle different from the nozzle from which the ink forming the raster line L1 is ejected. Will be. Therefore, the moving distance of the head 31 (nozzle row) in the row direction is not a quarter of the distance between nozzles (eg, 1/180 inch) (1/180 × 1/4 = 1/720 inch), The distance is larger than this.

  Thereafter, by performing the same operation, printing of the third pass and the fourth pass is executed, and the remaining raster lines shown in the figure (raster line L3 and pass 4 written as pass 3 on the right end). Raster line L4) is formed. Thus, by forming raster lines in four passes, the resolution of the image in the column direction can be made four times (= 720 ÷ 180).

  In the present embodiment, so-called bidirectional printing is performed. That is, the movement direction of the head 31 (nozzle row) when the first pass and the third pass printing are performed is different from the movement direction of the head 31 (nozzle row) when the second pass, the fourth pass and the second print are performed. The reverse direction (detailed later).

  In the following, an image forming operation (in other words, an ink ejection operation) of the printer 1 will be described as an operation example of the printer 1, but the case of FIG. In the description, reference is also made to FIG.

<Example of Image Forming Operation of Printer 1>
Here, a printing operation example of the printer 1 will be described with reference to FIGS. 5 and 6. FIG. 6 is a schematic diagram for explaining the movement of the head. Before explaining the printing operation, first, FIG. 6 (how to read) will be explained.

  FIG. 6 shows how the head moves during the printing process (that is, a series of processes related to image formation). Here, in order to make the description easy to understand, the description is made on the assumption that the number of heads 31 (and nozzle rows) is one instead of a plurality.

For convenience, the head 31 is represented by a circle (there are a large circle and a small circle in the figure, but there is no meaning in distinguishing both), and the movement of the head is represented by an arrow. Here, the arrow pointing in the left-right direction in the figure indicates the movement of the head in the transport direction, and the arrow pointing in the vertical direction indicates the movement of the head in the row direction. In addition, each arrow is provided with a reference numeral S1 to S10, which is a step number used in the description of the subsequent printing process.
Further, there are step numbers to which pass 1 to pass 4 are attached, and these step numbers represent steps in which an image forming operation is executed by ejecting ink.

  Hereinafter, the printing process will be described with reference to FIGS. 5 and 6. The printing process is realized mainly by the controller 60. In particular, in the present embodiment, it is realized by the CPU 62 processing a program stored in the memory 63. And this program is comprised from the code | cord | chord for performing the various operation | movement demonstrated below.

When the above-described intermittent roll paper 2 is transported and the roll paper 2 is stopped, a printing process for forming an image for one page on the portion of the roll paper 2 on the printing region R is started.
First, the controller 60 moves the carriage 42 (that is, each head) in the forward direction from the HP position (the direction from the upstream side to the downstream side in the direction in which the roll paper 2 is conveyed) (step S1).
The controller 60 performs the first pass printing by causing the head to eject ink while continuing the movement of the head 31 in the forward direction (step S2). As a result, the raster line L1 (raster line of pass 1) shown in FIG. 6 is formed.
When the head reaches the first folding position, the controller 60 moves the head in the column direction (step S3). In the present embodiment, the head is moved by the distance d.

Thereafter, the controller 60 performs the second pass printing by causing the head to eject ink while moving the head in the backward direction (the direction from the downstream side to the upstream side in the direction in which the roll paper 2 is conveyed). (Step S4). As a result, the raster line L2 (pass 2 raster line) shown in FIG. 6 is formed.
When the head reaches the second folding position, the controller 60 moves the head in the column direction (step S5). In the present embodiment, the head is moved by the distance d.

  Next, the controller 60 further performs the same processing as the processing from step S2 to step S4 (step S6 to step S8). In this process, the raster line L3 (raster line of pass 3) shown in FIG. 6 by the third pass printing (step S6) is changed to the raster line shown in FIG. 6 by the fourth pass printing (step S8). L4 (raster line of pass 4) is formed respectively. The controller 60 returns the position of the head in the row direction (step S9). That is, the head is moved by a distance 3d in the direction opposite to the direction in which the head has moved in steps S3, S5, and S7.

  Then, the controller 60 moves the head to the HP position (step S10), and ends the printing process for forming an image for one page. In this embodiment, image formation for one page is performed in four passes. However, the present invention is not limited to this. For example, image formation for one page may be performed in two passes.

  Further, in the present embodiment, plate printing for forming an image composed of a plurality of plates is performed by performing multiple printing on the same printing surface using a plurality of print data. Note that the plate is data for one printing process when overprinting is performed to create an image on the printing surface. Further, a printing surface for one page generated by overlapping plates is also referred to as a frame. Details of the plate printing will be described later.

<Outline of processing by printer driver>
As described above, the printing process starts when print data is transmitted from the host computer 110 connected to the printer 1. The print data is created by processing by the printer driver. Hereinafter, processing by the printer driver will be described with reference to FIG. FIG. 7 is an explanatory diagram of processing by the printer driver.

  The printer driver receives image data from the application program, converts it into print data in a format that can be interpreted by the printer 1, and outputs the print data to the printer. When converting image data from an application program into print data, the printer driver performs resolution conversion processing, color conversion processing, halftone processing, rasterization processing, command addition processing, and the like.

  The resolution conversion process is a process for converting image data (text data, image data, etc.) output from an application program into a resolution (print resolution) for printing on paper. For example, when the print resolution is specified as 720 × 720 dpi, the vector format image data received from the application program is converted into bitmap format image data with a resolution of 720 × 720 dpi. Note that each pixel data of the image data after the resolution conversion process is multi-gradation (for example, 256 gradations) RGB data represented by an RGB color space. This gradation value is determined based on RGB image data.

  The color conversion process is a process for converting RGB data into CMYK color space data. The CMYK color space is a color space corresponding to the ink (color) used in the printer 1. In other words, the printer driver creates CMYK system plane image data based on the RGB data. For example, when the ink to be used is four colors of CMYK, image data of the CMYK plane is created.

  This color conversion processing is performed based on a table in which gradation values of RGB data are associated with gradation values of CMYK data corresponding to the ink to be used. This table is called a color conversion lookup table (LUT). Note that the pixel data after the color conversion processing is data of 256 gradations expressed by a CMYK color space.

  The halftone process is a process for converting high gradation number data into gradation number data that can be formed by a printer. By this halftone processing, data indicating 256 gradations is converted into 1-bit data indicating 2 gradations or 2-bit data indicating 4 gradations. In the image data after halftone processing, 1-bit or 2-bit pixel data corresponds to each pixel, and this pixel data indicates the dot formation status (the presence / absence of dots, the size of dots) in each pixel. Become data. For example, in the case of 2 bits (4 gradations), no dot corresponding to the dot gradation value [00], formation of a small dot corresponding to the dot gradation value [01], and medium corresponding to the dot gradation value [10] It is converted into four stages like dot formation and large dot formation corresponding to the dot gradation value [11]. After that, after the dot creation rate is determined for each dot size, pixel data is created so that the printer 1 forms the dots in a dispersed manner using a dither method, γ correction, error diffusion method, or the like. .

  The rasterizing process rearranges the pixel data arranged in a matrix for each pixel data in the order of data to be transferred to the printer 1. For example, the pixel data is rearranged according to the arrangement order of the nozzles of each head.

  The command addition process is a process for adding data indicating a command corresponding to the printing method to the rasterized data. Examples of commands include a conveyance command, a suction command, and a carriage movement command.

Through these processes, color image print data (DC) is created.
In addition to the color image print data DC, the printer driver creates background image print data for background (DC) and image coating (OP) print data (DOP).
Each of these print data is transmitted to the printer 1 as data for each ink color by the printer driver.

<About print images>
FIG. 8 is a diagram showing an example of print data for one frame. In the present embodiment, one frame image is composed of three versions of data. That is, as shown in FIG. 8, a one-frame image is composed of the print data (DC) of the first plate, the print data (DW) of the second plate, and the print data (DOP) of the third plate. Each of these print data is sent from the host computer 110 to the printer 1 and temporarily stored in a buffer (not shown) of the memory 63 of the printer 1. In each print data, the hatched portion indicates an area for ejecting ink.

  The print data DC is data for printing a colored image (color image) with CMYK ink. The print data DC includes data for forming a color image (symbol “ABC”). In this embodiment, for simplification of description, an image (symbol “ABC”) is printed in cyan among the color inks. That is, the print data DC in FIG. 8 is cyan only (single color) data.

  The print data DW is data for printing a background image (a white background image in the present embodiment) that is the background of a color image. In the present embodiment, the print data DW is formed so that white ink is ejected to a region where no color image is formed in the print data DC. Specifically, as shown in FIG. 8, the print data DW is formed so that ink (white ink) is ejected around the symbol “ABC”. However, as will be described later, the color image and the background image may be formed to overlap each other.

  The print data DOP is data for forming a transparent coating (OP) on the image surface with clear ink. The print data DOP of this embodiment is data for applying clear ink (so-called solid printing) to the entire printing surface (printing area). In the present embodiment, clear ink ejection conditions are not defined in the print data DOP generated by the host computer 110. That is, the print data DOP is data indicating whether or not ink is ejected to each pixel on the printing surface. The clear ink ejection conditions are determined by the controller 60 of the printer 1 based on the print data DC and the print data DW (described later).

  FIG. 9 is a schematic diagram showing a printing process. First, the controller 60 performs a first printing process for ejecting CMYK ink (cyan in the present embodiment) on the printing surface (printing area) of the roll paper 2 based on the printing data DC shown in FIG. (S11). As a result, an image of a picture or a character (symbol “ABC” in this embodiment) is formed on the printing surface of the roll paper 2.

  Next, the controller 60 performs a second printing process for discharging white ink on the printing surface after the first printing based on the printing data DW (S12). As a result, a white background image is formed in the area around the symbol “ABC”.

  Further, the controller 60 performs a printing process for the third plate in which the clear ink is applied to the printing surface after the second plate is printed based on the print data DOP (S13). Thereby, coating (OP) is performed on the entire printing surface. Printing for one frame is completed by the printing process of the first to third plates. When the printing for one frame is completed, the controller 60 conveys the roll paper 2 to the printing position of the next page (S14). Thereafter, S11 to S14 are sequentially repeated.

  By the way, characteristics such as the ease of peeling of OP, glossiness, and ink fixing properties vary depending on the state of the ground at the place where the clear ink lands. For example, the ease of peeling, glossiness, and ink fixability differ between when clear ink is landed directly on a medium and when clear ink is landed on color ink. If all the clear ink is applied under the same conditions regardless of the state of the ground, for example, the clear ink may be applied more than necessary and the clear ink may be used wastefully. Or there is a possibility that gloss may not be obtained or peeled off due to insufficient application amount of clear ink.

  Therefore, in this embodiment, the ease of peeling, glossiness, and ink fixing for each of the medium type (base material), the color ink type (CMYK, etc.), and the background color ink type (white ink, metal ink). Parameters (values obtained by weighting each characteristic) are set, and clear ink discharge conditions (discharge amount and number of discharges) are determined based on the parameters.

<OP printing conditions>
FIG. 10 is a diagram illustrating an example of parameters for determining printing conditions for overprinting (OP). The table shown in FIG. 10 is stored in advance in the memory 63, for example, and is referred to when OP (third printing) is performed.

  As shown in the figure, the parameters of ease of peeling (characteristic 1), glossiness (characteristic 2), and ink fixability (characteristic 3) are shown for each of the medium (print medium), color ink, and background color ink. It has been established. More specifically, there are three types of media: substrate 1, substrate 2, and substrate 3, and color inks are cyan (C), magenta (M), yellow (Y), and black (K ) And green (G), and background inks include white ink and metallic ink. For each of these elements, parameters of ease of peeling (characteristic 1), glossiness (characteristic 2), and ink fixability (characteristic 3) are set.

  For example, for the base material 1, the ease of peeling is set to “4”, the glossiness is set to “7”, and the ink fixing property is set to “5”. For cyan (C) of the color ink, the ease of peeling is set to “3”, the glossiness is set to “5”, and the ink fixing property is set to “4”. For white ink, the ease of peeling is set to “7”, the glossiness is set to “5”, and the ink fixing property is set to “9”. The values of these parameters are added and summed as appropriate for each characteristic in accordance with the state of the base when performing OP. For example, when the cyan ink layer and the white ink layer are formed on the substrate 1, the total (sum) of the parameters is 14 (= 4 + 3 + 7) in the characteristic 1, 17 (= 7 + 5 + 5) in the characteristic 2, and the characteristic 3 is 18 (= 5 + 4 + 9).

FIG. 11 is a diagram illustrating an example of a correspondence relationship between a parameter totaling result and an OP printing condition. The table shown in FIG. 11 is also stored in advance in the memory 63, for example.
As shown in the figure, the amount of OP (that is, clear ink) ejection (discharge amount) and the number of times of clear ink ejection are determined in accordance with the result of summation (the sum of parameters).

  For example, when the parameter summation result (the sum of parameters in a certain characteristic) in FIG. 10 is 1 to 4, the clear ink is set to be ejected once with the ejection amount of small dots (S). For example, when the parameter summation result (the sum of parameters in a certain characteristic) is greater than 21, the clear ink is set to be ejected twice with a large dot (L) discharge amount. In order to drive the clear ink twice, for example, in the drive signal for driving the piezo element 321, two drive pulses for ejecting a corresponding amount of ink are provided in the ejection cycle of one pixel, and one pixel is ejected. The pulse may be applied to the piezo element 321 twice during the period.

<Control of clear ink placement>
The controller 60 performs the following operations when discharging clear ink.
First, the type of medium (print medium) in printing (the type of roll paper 2 in this embodiment) and which of the characteristics 1, 2, and 3 in FIG. This information is obtained by the user through the selection. In this embodiment, the base material 1 is used for the medium (roll paper 2), and information that priority is given to the ease of peeling (characteristic 1) is acquired.

In addition, the controller 60 determines whether or not there is a color ink to be ejected to the area on the print data DC (ink color) and printing for the area to eject the clear ink (for example, the area for each pixel on the medium). The presence / absence and type (white in the present embodiment) of the background color ink ejected to the area are determined on the data DW. That is, the base structure of the area where the clear ink is ejected is obtained based on the medium type and the print data DC and DW.
Then, according to the obtained base structure, the parameter values are totaled (added) with reference to FIG. 10, and the clear ink discharge condition is determined by comparing the result with the discharge condition of FIG. 11.

FIG. 12 is a conceptual diagram showing an example of a cross-sectional structure before performing OP in the present embodiment.
A substrate 1 is used as a medium (roll paper 2) for forming an image. In the printing process for the first plate, color ink (cyan) is ejected in sections 3 and 4 based on the print data DC (a color image is formed). In the printing process for the second plate, white ink is ejected in sections 2, 3, and 5 (a background image is formed) based on the print data DW. That is, the color image (cyan ink) and the background image (white ink) are formed overlapping (overlapping) in the section 3. In FIG. 12, the layer of the color ink C on the substrate 1 is printed by the first printing process, and the white ink layer printed thereon is printed by the second printing process. It is shown that. That is, the white inks in the section 2 and the section 5 in the figure actually land on the substrate 1.

  As described above, no image is formed on the base material 1 in the section 1. In sections 2 and 5, a white ink layer (background image) is formed on the substrate 1. In section 3, a layer of color ink (cyan) (color image) and a layer of white ink (background image) are formed on the substrate 1 in an overlapping manner. In section 4, a color ink (cyan) layer (color image) is formed on the substrate 1. Such a base structure for each section can be obtained from the print data of each color stored in the buffer of the memory 63.

  The controller 60 obtains the total value (sum) of the parameters 1, 2, and 3 from each print data and medium type with reference to the parameters shown in FIG.

FIG. 13 is a diagram showing the total value of parameters in each section for each characteristic.
For example, in the section 3, a color ink (cyan) layer and a white ink layer are formed on the substrate 1. In this case, characteristic 1 (ease of peeling) is 14 (= 4 + 3 + 7), characteristic 2 (glossiness) is 17 (= 7 + 5 + 5), and characteristic 3 (ink fixability) is 18 (= 5 + 4 + 9). Similarly, the controller 60 calculates the total of parameters in each section for each characteristic as shown in FIG.

  Then, the controller 60 refers to the table of FIG. 11 from the calculation result of FIG. FIG. 14 is a diagram illustrating calculation results of clear ink ejection conditions in each section. In the drawing, the OP driving amount “S” means a discharge amount for forming a small dot, “M” means a discharge amount for forming a medium dot, and “L” for forming a large dot. This means the discharge amount. The number of OP shots indicates the number of times clear ink is ejected to the same area. For example, the clear ink is ejected twice in a section where the OP driving frequency is “2” (OP is formed in two layers).

  FIG. 15 is a conceptual diagram showing a state in which OP is performed in the first embodiment. As described above, in the first embodiment, the condition of ease of peeling (characteristic 1) among the three characteristics is given priority. Therefore, FIG. 15 schematically shows a state where OP is performed under the condition of the characteristic 1 in FIG. In FIG. 15, the clear ink dot is shown above the position of the white ink, but this indicates that it is formed by the third printing process. That is, for example, in the section 1, the clear ink is landed on the substrate 1.

  In FIG. 15, the clear ink (clear dot) is indicated by three circles having different sizes according to the amount of ink applied. In addition, S, M, and L on the left side of the symbol above the circle mark indicate the amount of shots (that is, the size of dots to be formed: small dots, medium dots, and large dots). 1 time and 2 times). For example, S1 indicates that a small dot is formed once. Further, when dots (small dots) are formed twice as in section 3, the circles are shown as two upper and lower layers.

  As shown in FIG. 15 (and FIG. 14), in the section 1, the small dot is once, in the section 2, the large dot is once, in the section 3, the small dot is twice, in the section 4, the medium dot is once, in the section 5, A large dot is formed once. In this embodiment, priority is given to the ease of peeling (characteristic 1), and the clear ink discharge conditions are set. Thus, by setting the clear ink discharge conditions in this way, the coating (OP) is peeled off in each section. Ease can be improved.

  As described above, in the present embodiment, the clear ink ejection conditions are set according to the state of the base (base material, color ink, background color ink) and the characteristics (ease of peeling, glossiness, ink fixability) of the coating. It is changing. By so doing, it is possible to optimize the clear ink ejection conditions in each section (region).

<Modification of First Embodiment>
In the first embodiment described above, the sum of the parameters shown in FIG. 10 is obtained in each section according to the state of the background, but in this modified example, the sum of the parameters is obtained. In other words, the correspondence between each parameter value and the discharge condition is set so that the optimum discharge condition can be obtained when the product of each parameter is calculated. Note that the configuration of the printer 1 and the contents of the printing process are the same as those in the first embodiment, and thus description thereof is omitted. In this case as well, the clear ink discharge conditions can be optimized by determining the clear ink discharge conditions (discharge amount, number of discharges) according to the product of each parameter, as in the first embodiment. Note that when a plurality of color inks are used to form a color image as in the above-described embodiment, a sum may be obtained for the parameters for each color ink. In each section, the product of the medium parameter, the color ink parameter, and the background color ink parameter may be obtained. Even in this case, the clear ink discharge conditions can be optimized.

=== Second Embodiment ===
In the second embodiment, the method for determining the clear ink ejection conditions is different from that in the first embodiment. Note that the configuration of the printer 1 and the contents of the printing process are the same as those in the first embodiment, and thus description thereof is omitted.
In the first embodiment, the clear ink ejection condition is determined with emphasis on the characteristic 1 among the three characteristics, whereas in the second embodiment, the largest one of the characteristics (characteristics 1 to 3) for each section is determined. Is defined as the printing condition for the section.

FIG. 16 is a conceptual diagram showing a state in which OP is performed in the second embodiment. In addition, the description method of FIG. 16 is the same as that of 1st Embodiment (FIG. 15). In the following description, FIG. 14 is also used.
For example, in section 1 in FIG. 14, small dot (S) is formed once for characteristic 1, and medium dot (M) is formed once for characteristic 2 and characteristic 3. Since the medium dot is larger than the small dot (the discharge amount is large), in this case, the medium dot once (M1) is selected as the clear ink discharge condition of the section 1 as shown in FIG.

In the section 3 in FIG. 14, the characteristic 1 is set to form the small dot (S) twice, and the characteristics 2 and 3 are set to form the medium dot (M) twice. Since the medium dot is larger than the small dot (the discharge amount is large), the medium dot twice (M2) is selected as the clear ink discharge condition of the section 3 as shown in FIG.
In the section 4 in FIG. 14, the characteristic 1 is set to form the medium dot (M) once, and the characteristics 2 and 3 are set to form the large dot (L) once. Since the large dot is larger than the medium dot (the discharge amount is large), the large dot is selected once (L1) as the clear ink discharge condition in the section 4 as shown in FIG.
By doing so, OP can be performed under the condition where any one of the three characteristics (ease of peeling, glossiness, ink fixing property) is optimized in each section.

=== Third Embodiment ===
Also in the third embodiment, the method for determining the clear ink discharge conditions is different from that of the above-described embodiment. Note that the configuration of the printer 1 and the contents of the printing process are the same as those in the above-described embodiment, and thus description thereof is omitted.
For example, there is a case where it is required that the gloss of the printed material is within a range that does not exceed a predetermined value. In such a case, a printing mode with limited gloss (hereinafter referred to as gloss limiting mode) is performed. Specifically, when the gloss restriction mode is performed, the clear ink discharge conditions for each section are determined within a range that does not exceed the discharge condition of characteristic 2 in FIG. That is, the condition based on the characteristic 2 in each section is the clear ink maximum discharge condition. In other words, in each section, the clear ink is ejected with the ejection amount of the characteristic 2 and the ejection number or less.
By doing so, it is possible to perform optimum coating within a range where the gloss does not exceed a predetermined value.

=== 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 printer>
In the above-described embodiment, a printer has been described as an example of an apparatus, but the present invention is not limited to this. For example, color filter manufacturing apparatus, dyeing apparatus, fine processing apparatus, semiconductor manufacturing apparatus, surface processing apparatus, three-dimensional modeling machine, liquid vaporizer, organic EL manufacturing apparatus (particularly polymer EL manufacturing apparatus), display manufacturing apparatus, film formation The same technology as that of the above-described embodiment may be applied to various devices to which inkjet technology is applied, such as a device and a DNA chip manufacturing device.

  In the above-described embodiment, the lateral printer is used. However, the present invention is not limited to this. For example, a serial printer or a line printer may be used.

<Discharge method>
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>
Since the above-described embodiment is an embodiment of a printer, ink is ejected from a nozzle. However, this ink may be water-based or oil-based.

  In the above-described embodiment, a white background image is formed using white ink, but ink other than white ink may be used. For example, a background image having a color different from that of the printing medium may be formed using metallic ink having a color different from that of the printing medium (such as silver). The metallic ink is an ink in which a printed material exhibits a metallic feeling. As such a metallic ink, for example, an oil-based ink composition containing a metal pigment, an organic solvent, and a resin can be used. In order to effectively produce a visually metallic texture, the aforementioned metal pigment is preferably a plate-like particle. Such a metal pigment can be formed of, for example, aluminum or an aluminum alloy, or can be formed by crushing a metal vapor-deposited film. The concentration of the metal pigment contained in the metallic ink can be set to 0.1 to 10.0% by weight, for example. Of course, the metallic ink is not limited to such a composition, and any other composition can be adopted as long as it is a composition that produces a metallic feeling.

  In the above-described embodiment, the image coating (OP) is performed using the colorless and transparent clear ink. However, the present invention is not limited to this. For example, a semi-transparent color ink may be applied for coating.

<About images>
In the above-described embodiment, the symbol “ABC” is printed as a color image. However, the present invention is not limited to this, and a picture or a figure may be used. In the present embodiment, the image (symbol “ABC”) is printed in one color, but a color image may be printed using a plurality of color inks. In this case as well, the sum of the parameters of each color may be calculated for each section (region) based on the print data of each color (CMYK) stored in the memory 63 as in the above-described embodiment.

<About parameters>
In the above-described embodiment, the total (sum) of the parameters is calculated for each of the three characteristics of ease of peeling (characteristic 1), glossiness (characteristic 2), and ink fixability (characteristic 3). Calculate the sum of the parameters. For example, in the case of the first embodiment, the OP printing conditions are determined with priority given to ease of peeling (characteristic 1), and in this case, the sum of the parameters of only characteristic 1 may be calculated. Alternatively, the sum of the parameters may be calculated for two of the three characteristics, and either of them may be applied.

<About coating>
In the above-described embodiment, overprinting (OP) is performed by ejecting clear ink over the entire printing area, but the present invention is not limited to this. For example, the OP may be performed only on the color image, or the OP may be performed only on the background image. Alternatively, OP may be performed on the image formation area (color image + background image). In such a case as well, the clear ink ejection conditions may be determined by calculating the parameters of the area where OP is performed, as in the embodiment described above.

<Image formation order>
In the above-described embodiment, the background image is formed after the color image is formed. However, the present invention is not limited to this. For example, a color image may be formed after a background image is formed, and then OP may be performed. In this case as well, the clear ink ejection conditions may be determined based on the parameter calculation results in each section as in the above-described embodiment.

<Discharge conditions>
In the above-described embodiment, the clear ink ejection conditions are set so that both the clear ink ejection amount (ejection amount) and the number of ejections are changed based on the parameter aggregation results. However, the present invention is not limited to this. You may make it change either. For example, only the driving amount may be changed.

DESCRIPTION OF SYMBOLS 1 Printer, 2 roll paper, 10 Feeding unit, 18 winding axis, 19 Relay roller, 20 Transport unit, 21 Relay roller, 22 Relay roller, 23 1st transport roller, 23a 1st drive roller, 23b 1st driven roller, 24 second transport roller, 24a second drive roller, 24b second driven roller, 25 reversing roller, 26 relay roller, 27 delivery roller, 29 platen, 30 head unit, 31 head, 32 drive unit, 33 case, 34 flow path Unit, 35 Channel formation substrate, 36 Nozzle plate, 37 Elastic plate, 40 Carriage unit, 41 Guide rail, 42 Carriage, 50 Detector group, 60 Controller, 61 Interface unit, 62 CPU, 63 Memory, 64 Unit Control circuit, 70 cleaning unit, 80 take-up unit, 81 relay roller, 82 take-up drive shaft, 110 host computer, 321 piezo element, 323 fixed plate, 324 flexible cable, 331 empty space, 332 ink supply pipe, 351 Pressure chamber, 352 supply port, 353 reservoir

Claims (6)

A first ejection unit capable of ejecting color ink for forming an image;
A second ejection part capable of ejecting auxiliary ink for assisting the image;
Parameters set for each of the printing medium and the color ink,
A storage unit storing at least one parameter of ease of peeling, gloss, and ink fixing;
After the color ink is ejected from the first ejection unit to form the image on the printing medium, the first amount is ejected with respect to a predetermined area of the printing medium with a discharge amount or a number of ejections based on the parameter. A control unit for discharging the auxiliary ink from the two discharge units;
Have
A third ejection unit capable of ejecting a background color ink that forms a background image of the image;
The parameter is set for each of the printing medium, the color ink, and the background color ink,
The control unit discharges the color ink and the background color ink from the first discharge unit and the third discharge unit, respectively, and forms the image and the background image on the print medium, and then the print medium The auxiliary ink is ejected from the second ejection part at a ejection amount or ejection number based on the parameter for the predetermined region of
An image forming apparatus. The image forming apparatus according to claim 1 ,
The control unit causes the auxiliary ink to be ejected from the second ejection unit based on the sum of the parameters for the printing medium, the color ink, and the background color ink.
An image forming apparatus. The image forming apparatus according to claim 1 ,
The control unit causes the auxiliary ink to be ejected from the second ejection unit based on a product of the parameters for the printing medium, the color ink, and the background color ink.
An image forming apparatus. The image forming apparatus according to any one of claims 1 to 3 ,
A plurality of the first ejection portions corresponding to the color inks of a plurality of colors;
The control unit is configured to determine the second parameter based on a product of the parameter of the printing medium in the predetermined area, a sum of the parameters of the color inks of a plurality of colors, and the parameter of the background color ink. Causing the auxiliary ink to be discharged from the discharge portion;
An image forming apparatus. A first ejection unit capable of ejecting color ink for forming an image;
A second ejection part capable of ejecting auxiliary ink for assisting the image;
Parameters set for each of the printing medium and the color ink,
A storage unit storing at least one parameter of ease of peeling, gloss, and ink fixing;
After the color ink is ejected from the first ejection unit to form the image on the printing medium, the first amount is ejected with respect to a predetermined area of the printing medium with a discharge amount or a number of ejections based on the parameter. A control unit for discharging the auxiliary ink from the two discharge units;
Have
The control unit causes the auxiliary ink to be ejected from the second ejection unit to the predetermined region with the maximum ejection amount or the maximum number of ejections required for the ease of peeling, the glossiness, and the ink fixing property.
An image forming apparatus. The image forming apparatus according to any one of claims 1 to 4 , wherein:
The control unit causes the auxiliary ink to be ejected from the second ejection unit so as not to exceed the ejection amount calculated for the glossiness and the number of ejections in a printing mode for printing a printed matter with limited gloss.
An image forming apparatus.