JP2019059197A - Printer and printing method - Google Patents

Abstract

To improve printing efficiency of image data in which ink discharge for an overcoat is unnecessary in a printer discharging ink for forming an overcoat layer.SOLUTION: A printer comprises: a print head having a first nozzle discharging first ink containing color materials and a second nozzle discharging second ink causing a black density to be improved by being discharged onto the first ink; and a control part controlling discharge of the first ink and the second ink. The control part, when a prescribed value exists in image data, performs control so as to discharge the first ink from the first nozzle positioned at a prescribed region of the print head and the second ink from the second nozzle positioned at a region different from the prescribed region of the print head, and, when the prescribed value does not exist in the image data, performs control so as to discharge the first ink from the first nozzle positioned at a region wider than the prescribed region and not to discharge the second ink.SELECTED DRAWING: Figure 5

Description

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

  There is known a printing apparatus which records an image on a recording medium by applying ink ejected from a print head to a printing medium to form dots. In a printing apparatus using a highly durable pigment ink, it is strongly required to record high quality images on glossy paper as a printing medium. In an image printed using a pigment ink, the pigment (coloring material) deposited on the surface of the print medium causes unevenness, so that the reflected light reflected on the surface of the print medium is scattered and a desired black density can not be obtained. Sometimes. An overcoat layer of a colorless, milky white or white liquid composition (hereinafter referred to as "clear ink") containing fine resin particles is formed on a colored ink layer of pigment ink for the purpose of improving the black density, There has been proposed an ink jet recording apparatus (printing apparatus) that suppresses unevenness (see Patent Document 1).

JP 2012-51188 A

  However, the printing apparatus described in Patent Document 1 uses the nozzles of the region on the upstream half of the print head in the conveyance direction of the recording medium among the first nozzles capable of ejecting the first ink containing the coloring material. I was printing an image. Then, among the second nozzles capable of discharging the second ink (clear ink), the black density is improved using the nozzles in the downstream half area of the print head in the recording medium conveyance direction. In addition, the printing apparatus ejects the second ink to all the image data. That is, since the printing apparatus of Patent Document 1 always performs printing at 1/2 the printing speed with respect to the printing speed when the colored ink is discharged using the entire area of the print head, the second ink is discharged. There is a problem that printing efficiency is reduced in printing unnecessary image data.

  The present invention has been made to solve at least a part of the above-described problems, and can be realized as the following modes or application examples.

  Application Example 1 A printing apparatus according to this application example is a printing apparatus that prints an image on a printing medium based on image data, and includes a first nozzle that discharges a first ink containing a color material, and the first nozzle. A print head having a second nozzle that discharges a second ink whose black density is improved by discharging onto the ink, discharge of the first ink from the first nozzle, and the second discharge from the second nozzle (2) a control unit that controls the ejection of the ink, and when the image data has a predetermined value, the control unit controls the first ink from the first nozzle located in the predetermined area of the print head, The second ink is controlled to be ejected from the second nozzle located in the area different from the predetermined area of the print head, and when the predetermined value does not exist in the image data, an area wider than the predetermined area Ejecting the first ink from the first nozzle located, and controlling so as not to eject the second ink.

  According to this application example, the printing apparatus controls the ejection of the first ink from the first nozzle located in the predetermined area of the print head and the ejection of the second ink from the second nozzle located in the area different from the first nozzle. Control unit is provided. When the image data has a predetermined value, the control unit controls so as to eject the first ink from the first nozzle of the predetermined area and eject the second ink from the second nozzle other than the predetermined area. When a predetermined value does not exist in the image data, in other words, in the case of image data that does not have to discharge the second ink to improve the black density, only the first ink from the first nozzle in the area wider than the predetermined area Control to discharge. Therefore, it is possible to provide a printing apparatus in which the printing efficiency at the time of printing the image data which does not require the discharge of the second ink is improved.

  Application Example 2 In the printing apparatus according to the application example described above, when (RGB) = (0, 0, 0) exists in the image data, the control unit controls so as to discharge the second ink. When (RGB) = (0, 0, 0) does not exist in the image data, it is preferable to control so as not to discharge the second ink.

  According to this application example, the control unit controls so as to eject the second ink when (RGB) = (0, 0, 0) in the image data, that is, the so-called darkest point is included in the image data. Control is performed so that the second ink is not ejected when the data does not include the darkest point. Thus, the control unit can print image data that does not need to improve the black density using only the first ink.

  Application Example 3 In the printing apparatus according to the application example, it is preferable that the second ink is a clear ink.

  According to this application example, the printing apparatus includes the clear ink as the second ink. The clear ink is a colorless, milky white or white liquid composition containing resin fine particles. Under control of the control unit, the clear ink is discharged from the second nozzle, whereby an overcoat layer is formed on the surface of the printing medium to cover the unevenness due to the coloring material of the first ink, and light scattering on the surface of the printing medium Is suppressed. Thus, an image with improved black density can be formed.

  Application Example 4 In the printing apparatus according to the application example, the second ink is preferably a light black ink containing a black color material and having a density lower than that of the first ink.

  According to this application example, the printing apparatus includes, as the second ink, a light black-based ink containing a black color material whose density is lower than that of the first ink. Since the light black ink contains a small amount of coloring material, the control unit controls the control unit to eject the light black ink from the second nozzle to form a layer that smoothes the unevenness due to the coloring material of the first ink, and the printing medium Scattering of light at the surface of is suppressed. Thus, an image with improved black density can be formed.

  Application Example 5 In the printing method according to this application example, the first nozzle that discharges the first ink containing the coloring material, and the second ink whose black density is improved by being discharged onto the first ink. A printing method for printing an image on a printing medium based on image data using a printing apparatus including a print head having a second nozzle for discharging, and determining whether or not a predetermined value exists in the image data. In the determining step, when the predetermined value is present in the image data, the first nozzle located in a predetermined area of the print head, the first ink located in a predetermined area, and the second area located in an area different from the predetermined area A first discharge step of discharging the second ink from the nozzle; and discharging the first ink from the first nozzle positioned in a region wider than the predetermined region when the predetermined value does not exist in the image data A second discharge step that, characterized in that it comprises a.

  According to this application example, the printing method includes the determination step of determining whether the image data has a predetermined value, and the first discharge step or the second discharge step is performed according to the determination result. Do. When the image data has a predetermined value, the first ink is ejected from the first nozzle in the predetermined area, and the second ink is ejected from the second nozzle other than the predetermined area in the first ejection step. When a predetermined value does not exist in the image data, in other words, in the case of image data in which it is not necessary to eject the second ink to improve the black density, the second ejection step performs the first ejection of the area wider than the predetermined area. Only the first ink is ejected from the nozzle. This makes it possible to improve the printing speed of image data that does not require the discharge of the second ink. Therefore, a printing method with improved printing efficiency can be provided.

FIG. 1 is a block diagram showing a schematic configuration of a printing apparatus as an embodiment of the present invention. Explanatory drawing which shows the arrangement | positioning state of the nozzle with which a printing head is equipped. FIG. 2 is a block diagram showing a schematic configuration of a print control device. 3 is a flowchart showing the procedure of image processing. 3 is a flowchart showing a printing method.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the following drawings, the scale of each layer or each member is made different from the actual size in order to make each layer or each member recognizable.

(Embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a printing apparatus according to an embodiment of the present invention. The printing apparatus 100 is a printing apparatus that prints an image on a print medium P based on image data. In the present embodiment, the printing apparatus 100 includes the print control apparatus 200, and controls according to dot pattern data (data indicating a dot row discharged by a print head included in the printing apparatus) generated by the print control apparatus 200 based on image data. The unit 40 drives the print head 61 to print an image on the print medium P.

  In the present embodiment, the printing apparatus 100 is an ink jet printer, and is discharged onto the first ink, the third ink, the fourth ink, the fifth ink, and these inks containing a coloring material, and thus the black density is obtained. The second ink, which is improved, is configured to be able to be discharged onto the print medium P. Specifically, the first ink is dark black (Pk) ink, the third ink is yellow (Y) ink, the fourth ink is magenta (M) ink, and the fifth ink is cyan (C) ink. Each corresponds. In the present embodiment, clear (Go) ink is employed as the second ink for improving the black density. Further, the coloring material employed in the first, third to fifth inks of the present embodiment is a pigment.

  The printing apparatus 100 includes an operation panel 32, a connection interface unit 34, a control unit 40, a carriage motor 50, an endless drive belt 51, a pulley 52, a support rod 53, a carriage 60, and a paper feed motor 81. And a paper feed roller 82.

  The operation panel 32 receives an operation of setting a print mode by the user, and an instruction operation of various maintenance operations such as test pattern printing. In addition, a display (not shown) is provided on the operation panel 32, and various menu screens, the status of the printing apparatus 100, and the like are displayed. The connection interface unit 34 is connected to the print control device 200 by a predetermined cable, receives dot pattern data transmitted by the print control device 200, and passes it to the control unit 40.

  The control unit 40 drives the print head 61 attached to the carriage 60 to discharge the first ink from the first nozzle described later and the discharge of the second ink from the second nozzle described later. 5. Control the discharge of the ink onto the print medium P. The control unit 40 also controls the reciprocating operation of the carriage 60 in the main scanning direction MD and the transport operation of the print medium P in the sub scanning direction SD. In the present embodiment, the main scanning direction MD and the sub scanning direction SD are orthogonal to each other. Note that, in FIG. 1, the upstream side and the downstream side in the transport direction of the print medium P are clearly shown along the sub scanning direction SD.

  The carriage motor 50 reciprocates the carriage 60 via the drive belt 51. The drive belt 51 is bridged between the carriage motor 50 and the pulley 52. The support rod 53 is a rod-like member extending in parallel to the main scanning direction MD, and supports the carriage 60 so as to be capable of reciprocating in the main scanning direction MD.

  The printing apparatus 100 is a so-called on-carriage type printer, and a total of five ink cartridges 71, 72, 73, 74, 75 corresponding to the first to fifth inks are mounted on the carriage 60. In the present embodiment, the ink cartridge 71 contains a first ink. Further, the second ink is stored in the ink cartridge 72, the third ink is stored in the ink cartridge 73, the fourth ink is stored in the ink cartridge 74, and the fifth ink is stored in the ink cartridge 75.

  Further, a print head 61 is attached to an end of the carriage 60 facing the print medium P. The print head 61 improves the black density by discharging the first and third to fifth nozzles described later that discharge the first and third to fifth inks containing a color material, and the first ink. It has the below-mentioned 2nd nozzle which discharges the 2nd ink. The print head 61 discharges the first to fifth inks stored in the ink cartridges 71 to 75 from the nozzles according to an instruction from the control unit 40.

  FIG. 2 is an explanatory view showing the arrangement of the nozzles provided in the print head 61. As shown in FIG. In FIG. 2, the surface of the print head 61 facing the print medium P is shown. In the print head 61, on the surface facing the print medium P, a nozzle group corresponding to each ink cartridge provided in the carriage 60 is provided. Specifically, a second nozzle group 92 as a second nozzle that discharges the second ink and a first nozzle group 91 as a first nozzle that discharges the first ink in order from the left in the drawing along the main scanning direction MD. A third nozzle group 93 for ejecting the third ink, a fourth nozzle group 94 for ejecting the fourth ink, and a fifth nozzle group 95 for ejecting the fifth ink are arranged side by side. Each of the nozzle groups 91 to 95 is configured by two nozzle rows each including a large number of nozzles nz arranged at predetermined intervals along the sub scanning direction SD.

  The print head 61 includes a nozzle area A including a predetermined number of nozzles nz in each of the nozzle groups 91 to 95 on the upstream side, and a nozzle area B including a nozzle nz not included in the nozzle area A on the downstream side. . Each of the nozzle groups 91 to 95 in the nozzle area A and the nozzle area B can eject the ink corresponding to each in accordance with an instruction from the control unit 40. In the present embodiment, in the nozzle area A and the nozzle area B, the nozzles nz which are 1/2 of the total number of nozzles in each of the nozzle groups 91 to 95 are allocated to the respective areas.

For example, when forming the overcoat layer with the clear ink Go (second ink), after the first, third to fifth inks containing the coloring material are discharged to form an image, the second ink is discharged. It is necessary to form an overcoat layer. Therefore, the control unit 40 causes the nozzles nz belonging to the nozzle area A located on the upstream side among the first, third to fifth nozzle groups 91, 93 to 95 to eject the first, third to fifth inks. . Thereafter, the print medium P is moved in the sub scanning direction SD, and the second ink is ejected from the nozzles nz belonging to the nozzle area B located on the downstream side in the second nozzle group 92.
When the overcoat layer is not formed, the controller 40 controls the first to third nozzles nz from the first to third nozzle groups 91 and 93 to 95 belonging to the nozzle area A and the nozzle area B. Discharge the fifth ink.

  FIG. 3 is a block diagram showing a schematic configuration of the print control device 200. As shown in FIG. In the present embodiment, the print control device 200 is configured by a computer. The print control device 200 includes a CPU 21, a ROM 22, a RAM 23, a hard disk drive 24, and a connection interface unit 25. The CPU 21, the ROM 22, the RAM 23, the hard disk drive 24, and the connection interface unit 25 are all connected to the internal bus 26 and can mutually transmit and receive data. The control unit 40 and the display device 27 described above are connected to the print control device 200 via the connection interface unit 25.

  In the print control apparatus 200, various computer programs such as a control program, a printer driver for the printing apparatus 100, and a video driver are executed under a predetermined operating system. The CPU 21 develops these computer programs in the RAM 23 and executes them to execute an input unit 211, a color conversion unit 212, a halftone processing unit 213, an interlace processing unit 214, and a print instruction unit 215 necessary for executing image processing. Function. Alternatively, it functions as a display control unit 216 that causes the display device 27 to display an image based on image data and various menu screens. The various computer programs described above are stored in advance in the ROM 22 or the hard disk drive 24. Instead of being stored in advance in the ROM 22 or the hard disk drive 24, it is stored in advance in a recording medium such as a CD-ROM or a memory card, and the recording medium is included in a media drive (not shown) that the print control device 200 has. It may be inserted to read out various computer programs from the recording medium.

  The input unit 211 causes the ROM 22 or the hard disk drive 24 to store image data input via an input / output interface (not shown). The CPU 21 executes image processing to be described later on the stored image data via the color conversion unit 212, the halftone processing unit 213, the interlace processing unit 214, and the print instruction unit 215, and transmits the dot pattern data to the control unit 40. Send

  FIG. 4 is a flowchart showing the procedure of image processing. Next, image processing performed in the print control device 200 of the printing apparatus 100 will be described with reference to FIG.

  In the color conversion process (step S100), in the color conversion unit 212 of the print control device 200, data (hereinafter referred to as “the color“ red ”,“ G ”(green), and“ B ”(blue)) included in the image data In the process of converting RGB data into data (hereinafter referred to as “ink color data”) consisting of gradation values of ink colors (Pk, Go, Y, M, C) used in the printing apparatus 100 is there.

  In the halftoning process (step S101), the halftoning unit 213 of the printing control apparatus 200 reduces the tone value of the ink color data obtained in step S100 to the number of tones that can be expressed by forming dots. It is a process of performing tone processing. In the present embodiment, the CPU 21 performs halftone processing by the error diffusion method in the halftone processing unit 213.

  In the interlace processing (step S102), dots formed by the main scanning of the carriage 60 in the printing apparatus 100 based on the data after halftone processing obtained in step S101 in the interlace processing unit 214 of the print control apparatus 200 This is a step of performing processing to rearrange dot pattern data indicating a column.

The print instruction (step S103) is a step of transmitting the dot pattern data obtained in step S102 to the control unit 40 of the printing apparatus 100 in the print instruction unit 215 of the print control apparatus 200.
The image processing shown in FIG. 4 is executed in steps S202a and S202b in the flowchart of the printing method described below.

  FIG. 5 is a flowchart showing the printing method in the present embodiment. Next, a printing method of the printing apparatus 100 will be described with reference to FIG.

  Step S200 is an image reading process in which the input unit 211 reads image data (RGB data) specified by the user. The CPU 21 causes the ROM 22 or the hard disk drive 24 to store image data input via an input / output interface (not shown).

  Step S201 is a determination step of determining whether or not a predetermined value exists in the image data input in step S200. In the present embodiment, it is determined whether or not the image data includes the darkest point of (RGB) = (0, 0, 0) as a predetermined value. When the predetermined value exists (step S201: Yes), the process proceeds to step S202a. If the predetermined value does not exist (step S201: No), the process proceeds to step S202b.

  Step S202a is an image processing step performed on image data for which it is determined that the black density needs to be improved when a predetermined value exists in the image data. The CPU 21 performs color conversion processing and halftone processing for outputting ink color data (Pk, Go, Y, M, C) consisting of the first to fifth inks including the second ink (clear ink (Go)). Do. Then, in the interlacing process, the first and third to fifth inks are ejected from the nozzle nz belonging to the nozzle area A located on the upstream side among the first to third nozzle groups 91 and 93 to 95, The dot pattern data for discharging the second ink from the nozzles nz belonging to the nozzle area B located on the downstream side in the second nozzle group 92 is generated.

  In step S203a, when the image data has a predetermined value, the first nozzle from the first nozzle located in the predetermined area of the print head 61 and the second ink from the second nozzle located in the area different from the predetermined area This is a first discharge step of discharging. In the present embodiment, when (RGB) = (0, 0, 0) exists in the image data, the second ink is ejected to form an overcoat layer. The control unit 40 controls the first to third nozzles nz belonging to the nozzle area A as the predetermined area of the print head 61 among the first to third nozzle groups 91 and 93 to 95 of the print head 61. 5 Eject the ink. Then, after moving the print medium P in the sub scanning direction SD, the second ink is ejected from the nozzles nz belonging to the nozzle area B as an area different from the predetermined area of the print head 61 in the second nozzle group 92. With the clear ink (Go) as the second ink, an overcoat layer is formed on the surface of the printing medium P to cover the unevenness generated by the coloring materials of the first ink and the third to fifth inks. Scattering of the light reflected by Thus, an image with improved black density is formed.

  Step S202b is an image processing step performed on image data for which it is determined that it is not necessary to improve the black density when the image data does not have a predetermined value. The color conversion processing for outputting the ink color data (Pk, Y, M, C) consisting of the first, third to fifth inks except the second ink (clear ink (Go)), and the halftone processing I do. Then, in the interlacing process, dot pattern data is generated in which the first and third to fifth inks are ejected from all the nozzles nz of the first and third to fifth nozzle groups 91 and 93 to 95.

  Step S203 b is a second ejection step of ejecting the first ink from the first nozzle positioned in a region wider than the predetermined region when the predetermined value does not exist in the image data. In the present embodiment, when (RGB) = (0, 0, 0) does not exist in the image data, the second ink is not ejected, so the image data that does not need to improve the black density is printed using only the first ink. be able to. The control unit 40 selects all of the first, third to fifth nozzle groups 91, 93 to 95 of the print head 61 belonging to the nozzle area A and the nozzle area B as areas wider than the predetermined area of the print head 61. The first, third to fifth inks are ejected from the nozzle nz. In other words, in the case of the image data in which the predetermined value does not exist, the print head 61 does not eject the second ink, so that the first, third to fifth inks can be ejected from all the nozzles nz. Thereby, the printing speed at the time of printing the image data which does not need to improve the black density is improved.

As described above, according to the printing apparatus 100 and the printing method of the printing apparatus 100 according to the present embodiment, the following effects can be obtained.
According to the present embodiment, the printing apparatus 100 controls the discharge of the first ink from the nozzle area A in the print head 61 and the control unit that controls the discharge of the second ink from the nozzle area B located in an area different from the nozzle area A. It has 40. When the image data has a predetermined value ((RGB) = (0, 0, 0)), the control unit 40 selects one of the first, third to fifth nozzle groups 91, 93 to 95 of the print head 61. The first and third to fifth inks are ejected from the nozzle nz located in the nozzle area A, and the second ink from the nozzle nz of the nozzle area B located in an area different from the nozzle area A in the second nozzle group 92 Discharge. Thus, an image with improved black density can be formed.

  Further, when the predetermined value ((RGB) = (0, 0, 0)) does not exist in the image data, the control unit 40, in other words, an image which does not need to discharge the second ink to improve the black density. In the case of data, the first and third to fifth inks are discharged from all the nozzles nz located in the nozzle area A and the nozzle area B among the first, third to fifth nozzle groups 91 and 93 to 95. . As a result, it is possible to improve the printing speed of image data that does not need to improve the black density. Therefore, it is possible to provide the printing apparatus 100 in which the printing efficiency of the image data which does not require the discharge of the second ink is improved.

  When the image data has a predetermined value ((RGB) = (0, 0, 0)), the control unit 40 performs the first, third to fifth nozzle groups of the print head 61 in the first ejection step. Of 91, 93 to 95, the first, third to fifth inks are ejected from the nozzle nz located in the nozzle area A, and the nozzle area B located in an area different from the nozzle area A in the second nozzle group 92 The second ink is ejected from the nozzle nz. Thus, an image with improved black density can be formed.

  Further, when the predetermined value ((RGB) = (0, 0, 0)) does not exist in the image data, the control unit 40 performs the first, third to fifth nozzle groups 91, The first and third to fifth inks are ejected from all the nozzles nz located in the nozzle area A and the nozzle area B among 93 to 95, and the second ink is not ejected. As a result, it is possible to improve the printing speed of the image data that does not need to improve the black density. Therefore, it is possible to provide a printing method capable of improving the printing efficiency of image data which does not require the discharge of the second ink.

  The present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification is described below.

  In the above embodiment, the printing apparatus 100 includes the clear ink as the second ink, but as the second ink, a light black ink containing a black color material and having a density lower than that of the first ink may be employed. Is also possible.

  The light black ink is ejected from the nozzles nz of the nozzle area B of the second nozzle group 92 under the control of the control unit 40, whereby the color materials of the first ink, the third ink, the fourth ink, and the fifth ink are used. A layer for smoothing the unevenness is formed, and scattering of light on the surface of the print medium P is suppressed. Thus, an image with improved black density can be formed.

  Although the printing apparatus 100 includes the print control apparatus 200 in the above embodiment, the printing apparatus is separated into the printing apparatus main body excluding the print control apparatus 200 from the printing apparatus 100 and the print control apparatus 200. It may be a configuration. In such a configuration, the control unit 40 may be provided on the print control device 200 side.

  In the above embodiment, the printing apparatus 100 is an on-carriage type printer, but an off-carriage type printer, that is, an ink tank is provided separately from the carriage 60 and the ink from the ink tank to the print head 61 by a tube etc. May be a type of printer that supplies Further, the present invention is not limited to a printer, and is an apparatus for printing an image on a print medium based on image data, such as a facsimile machine or a multifunction machine, and any apparatus that forms an image by discharging ink. It may apply.

  Although the darkest point is specified using the RGB value as the predetermined value in the image specified based on the read image data (RGB data) in the above embodiment, the present invention is not limited to the RGB value, for example, L It may be specified using tone values of other color spaces such as * a * b *, CMY, HSV.

  Although the predetermined value is (RGB) = (0, 0, 0) in the above embodiment, the present invention is not limited to this. For example, (RGB) = (0, 0, 0) to (30, 30, 30) A plurality of values within the range of may be set as predetermined values.

  The present invention is not limited to the above-described embodiment, and can be realized in various configurations without departing from the scope of the invention. For example, the technical features in the embodiments corresponding to the technical features in the respective forms described in the section of the summary of the invention, and the technical features in the modification may be used to solve some or all of the problems described above, or In order to achieve some or all of the effects of the above, it is possible to replace or combine as appropriate. Also, if the technical features are not described as essential in the present specification, they can be deleted as appropriate.

  DESCRIPTION OF SYMBOLS 21 ... CPU, 22 ... ROM, 23 ... RAM, 24 ... Hard disk drive, 25 ... Connection interface part, 26 ... Internal bus, 27 ... Display apparatus, 32 ... Operation panel, 34 ... Connection interface part, 40 ... Control part, 50 ... Carriage motor, 51 ... drive belt, 52 ... pulley, 53 ... support rod, 60 ... carriage, 61 ... print head, 71 to 75 ... ink cartridge, 81 ... paper feed motor, 82 ... paper feed roller, 91 to 95 ... Nozzle group 100 printing device 200 printing control device 211 input unit 212 color conversion unit 213 halftone processing unit 214 interlacing processing unit 215 printing instruction unit 216 display control unit MD: main scanning direction, P: printing medium, SD: sub scanning direction, A: nozzle area, B: nozzle area, nz Nozzle.

Claims (5)

A printing apparatus for printing an image on a print medium based on image data, comprising:
A print head having a first nozzle for discharging a first ink containing a coloring material, and a second nozzle for discharging a second ink whose black density is improved by discharging onto the first ink;
A control unit configured to control the discharge of the first ink from the first nozzle and the discharge of the second ink from the second nozzle;
The control unit
When a predetermined value exists in the image data, the first ink from the first nozzle located in the predetermined area of the print head, the second ink located in the area different from the predetermined area of the print head, and the second ink Control to eject the second ink,
When the predetermined value does not exist in the image data, the first ink is ejected from the first nozzle located in a region wider than the predetermined region, and the second ink is controlled not to be ejected. Printing device. The control unit
When (RGB) = (0, 0, 0) exists in the image data, control is performed to eject the second ink,
The printing apparatus according to claim 1, wherein control is performed so as not to discharge the second ink when (RGB) = (0, 0, 0) does not exist in the image data.   The printing apparatus according to claim 1, wherein the second ink is a clear ink.   The printing apparatus according to claim 1, wherein the second ink is a light black ink containing a black coloring material and having a density lower than that of the first ink. A printing apparatus comprising a print head having a first nozzle for discharging a first ink containing a coloring material, and a second nozzle for discharging a second ink whose black density is improved by discharging onto the first ink. A printing method for printing an image on a print medium based on image data using
A determination step of determining whether or not a predetermined value exists in the image data;
When the predetermined value exists in the image data, the first nozzle located in a predetermined area of the print head to the first ink, and the second nozzle located in an area different from the predetermined area 2) a first ejection step of ejecting ink;
A second discharge step of discharging the first ink from the first nozzle located in a region wider than the predetermined region when the predetermined value does not exist in the image data;
A printing method comprising:

Images