JP2006173885A - Image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an output image not only having a wide color reproduction region but also corresponding to an extended color space. <P>SOLUTION: In the method for forming an image on the basis of pixel data by using at least yellow recording agent, magenta recording agent, cyan recording agent, and a fourth recording agent, a color represented on a recording medium with the fourth recording agent has intensity and saturation higher than those in a color reproduction region represented on the recording medium with combination of the yellow recording agent and cyan recording agent on the color space of CIE-L<SP>*</SP>a<SP>*</SP>b<SP>*</SP>, and the hue angle at maximum saturation on the color space is 130-160°. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming method and an image forming apparatus, and more specifically, it is possible to obtain an image on a recording medium that is vivid, has high contrast, transparency, and three-dimensional effect, and smoothly expresses a color change. The present invention relates to an image forming method and an image forming apparatus.

  Conventionally, offset printing, gravure printing, electrophotographic printing, inkjet recording methods, and the like are widely used as methods for forming full-color images. Among these image forming methods, the ink jet recording method is personal because of its low noise, low manufacturing cost, small size of the apparatus, and easy colorization of recorded images. Widely used in printers, facsimiles, copiers, etc. for youth and office use.

  In many of these image forming methods, when a full-color image is formed, an image is formed based on subtractive color mixture, so that color reproduction using three primary colors yellow, magenta, and cyan is performed. Further, while using black ink in addition to these three primary color inks, the black component K is extracted from the data Y, M, and C of each color of yellow, magenta, and cyan and replaced with black. By performing UCR processing that removes the Y color component, there is an improvement in contrast or stable reproduction of neutral colors. As a result, for example, it is possible to form an image of an orange or red region by mixing yellow and magenta, a green region by mixing yellow and cyan, and a blue or violet region by mixing magenta and cyan. An area can be expressed.

  Further, the full color printing technique requires a printing method having a wide color reproduction region such as reproduction of a natural image. For this reason, materials having good color developability have been widely proposed as recording materials for recording materials of yellow, magenta and cyan, which are basic three primary colors. However, if you try to represent the entire range of hue with the three primary colors, even if you use the three primary colors with good color developability, the colors that can be expressed are not sufficiently saturated in the color area expressed by the mixed colors of the three primary colors. The reproduction area may be insufficient. Therefore, in addition to the above yellow, magenta and cyan, an image is formed using a recording medium such as red, orange, green, violet and blue having a hue angle intermediate in the hue space (hereinafter referred to as a special color). A method of performing is proposed.

  For example, an ink set including basic three primary color inks having specific hue angles and red and blue inks is disclosed. Further, there is a proposal for improving the color gamut and improving the graininess and glossiness by using red and blue inks having lightness lower than that of magenta and cyan inks, respectively (see, for example, Patent Document 1).

  Also, an ink set including basic three primary color inks using magenta ink containing a specific dye and any of orange, green, and violet inks is disclosed, and there is also a proposal to increase the color gamut by adding special colors ( For example, see Patent Document 2).

Furthermore, an inkjet printing method is disclosed in which red, green, and blue inks are added to three primary colors of yellow, magenta, and cyan, and specifically, a printing method that uses a vat dye for each of these color inks is disclosed. (For example, refer to Patent Document 3). Similarly in this patent document 3, by expressing the intermediate color with basic colors and special colors having similar hues along with the expansion of the color gamut, the granularity is reduced and the gradation of the color is improved compared to the case where the intermediate color is expressed with only the basic color. I am trying.
International Publication No. 02/100959 Pamphlet JP 2003-34765 A Japanese Patent Laid-Open No. 2002-241661

  However, the widespread use of recording apparatuses, especially recording apparatuses using the inkjet recording method, up to personal users has created a demand for further improvement in image quality. In recent years, with the development of input devices such as digital cameras that support not only sRGB corresponding to the color space of conventional monitors but also extended color spaces such as AdobeRGB and WideGamutRGB, these expanded colors have also been developed on the printer side which is an output device. There is a growing demand for space. However, it is not sufficient to simply add a spot color (for example, red, orange, green, violet, blue, etc.) having an angle in the middle region of the three primary colors of printing in the hue space.

For example, in Patent Documents 1 to 3, in an image forming method in which a special color (green) ink in an intermediate region between yellow and cyan is added in a hue space, CIE (International Lighting Commission) -L ^* a ^* b ^* Although there is an effect of enlarging the color reproduction region of the green region on the a ^* b ^* plane in FIG. 4, there is no definition of specific lightness, saturation, hue angle, etc., and it is not sufficient to support the extended color space. there were.

In order to solve these problems, the present invention provides an image forming method or apparatus for forming an image based on pixel data using at least a yellow recording agent, a magenta recording agent, a cyan recording agent, and a fourth recording agent. In the color space of CIE-L ^* a ^* b ^* , the color expressed on the recording medium by the fourth recording agent is a combination of the yellow recording agent and the cyan recording agent. An image forming method or an image forming apparatus, characterized by having lightness and saturation higher than a color reproduction region expressed on a recording medium, and a hue angle of maximum saturation in the color space being 130 to 160 degrees It is.

  Preferably, the image forming method or apparatus further has lightness and saturation higher than a color reproduction region expressed on the recording medium by a combination of the yellow recording agent and the cyan recording agent, and the color space. The fifth recording agent having a hue angle of 100 to 130 degrees on the maximum saturation is exchanged between the fourth recording agent and the fifth recording agent in accordance with the type of image and the printing purpose. An image forming method or an image forming apparatus according to claim 1, which is used, is also conceivable.

  According to the present invention, not only a wide color reproduction area but also an image color input in an extended color space can reproduce a true color with high saturation and high brightness compared to the conventional color in the green area.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

(Outline of image formation)
The image forming method or apparatus of the present embodiment uses at least yellow, magenta, cyan, and a fourth recording material having an angle between yellow and cyan in the hue space. It is characterized in that image formation is performed after selecting each color recording agent that satisfies the following conditions. That is,
Condition 1: In the CIE-L ^* a ^* b ^* color space, the color expressed on the recording medium by the fourth recording agent is a color expressed on the recording medium by the combination of the yellow recording agent and the cyan recording agent. Higher brightness and saturation than the reproduction area,
Condition 2: In the CIE-L ^* a ^* b * color space, the hue angle of the maximum saturation of the color expressed on the recording medium with the fourth recording agent is 130 to 160 degrees.
It is.

  As the image forming method or apparatus used in the present invention, a conventionally used method or apparatus such as an offset printing method, gravure printing, electrophotographic printing, inkjet recording or the like can be used. Here, in describing the configuration requirements or conditions of the present invention in detail, an ink jet recording technique will be exemplified as an image forming method or apparatus preferably applicable to the present invention. In the ink jet recording technology, for example, an image having a continuous hue from yellow to green to cyan is recorded by combining yellow and magenta inks, which are basic colors, and a fourth ink at an arbitrary ratio on a recording medium. This is because it can be formed on a medium and is a preferable recording technique.

  First, condition 1 will be described.

FIG. 1 shows the color reproduction areas of yellow, cyan, and fourth ink on the LC plane in the green hue of CIE-L ^* a ^* b ^* (C is the root of the sum of squares of a ^* and b ^* ), and AdobeRGB The horizontal axis represents the saturation C and the vertical axis represents the lightness L. FIG. Here, a range surrounded by a dotted line is a color reproduction region expressed by yellow, cyan, and fourth ink, and a range surrounded by a solid line is a color reproduction region expressed by only yellow and cyan ink, indicated by a thick line What is the color reproduction area of AdobeRGB.

  As apparent from FIG. 1, in order to reproduce the color defined in the extended color space such as AdobeRGB, it is strongly preferable to output the hue color of the green region, but with yellow ink and cyan ink alone It is difficult to fully express these colors. Therefore, as mentioned as Condition 1, it is effective to use the fourth ink having higher brightness and saturation than the color reproduction region expressed on the recording medium by a combination of yellow ink and cyan ink.

  Next, condition 2 will be described.

FIG. 2 is a diagram of the a ^* b ^* plane near the green hue (second quadrant) of CIE-L ^* a ^* b ^* , where the horizontal axis is a ^{* and the} vertical axis is b ^* . As shown in FIG. 3, the range surrounded by the dotted line is the color reproduction region expressed by yellow, cyan and fourth ink, and the range surrounded by the solid line is the color reproduction region expressed by only yellow and cyan ink, indicated by the bold line What is the color reproduction area of AdobeRGB.

As can be seen from this, in order to more effectively output the color reproduction of AdobeRGB, the hue angle of the maximum saturation of the fourth ink is a ^* b ^* in accordance with the area where the color reproduction range of AdobeRGB is widened ^. It is preferable that it is 130-160 degree | times in a plane. This is preferably the same hue angle in WideGamutRGB.

  In the following, as an example to which the present invention is applied, the basic colors of cyan, magenta, and yellow, the fourth green and black, and 7 of light cyan and light magenta are used to improve the graininess of highlights. An example of a printing system using color ink will be described.

<Print system overview>
FIG. 3 is a block diagram illustrating a configuration of a print system which is an example of an application target of the present invention. The image forming apparatus of the present embodiment performs printing with the above seven colors of ink, and for this purpose, a recording head that discharges these seven colors of ink is used. As shown in FIG. 3, the printing system of this embodiment includes a recording device as an image forming device and a personal computer (PC) as a host device.

  There are applications and printer drivers as programs that operate in the operating system of the host device. The application J0001 executes processing for creating image data to be printed by the printer. This image data or data before editing or the like can be taken into a PC via various media. The PC according to the present embodiment can capture, for example, JPEG image data captured by a digital camera using a CF card. Also, for example, TIFF format image data read by a scanner or image data stored in a CD-ROM can be captured. Furthermore, data on the web can be taken in via the Internet. These captured data are displayed on the monitor of the PC and edited, processed, etc. via the application J0001, and for example, sRGB standard image data R, G, B are created. Then, the image data is transferred to the printer driver in response to a printing instruction.

  The printer driver of this embodiment has a pre-stage process J0002, a post-stage process J0003, a γ correction J0004, a halftoning J0005, and a print data creation J0006 as the processes. The pre-stage process J0002 performs color gamut mapping. The pre-stage processing J0002 of the present embodiment is a three-dimensional LUT that contains the relationship of mapping the color gamut reproduced by the image data R, G, B of the sRGB standard into the color gamut reproduced by the printer of the printing system. Using this, interpolation conversion is also used to perform data conversion for converting 8-bit image data R, G, B into data R, G, B in the printer color gamut. The post-stage processing J0003 is based on the data R, G, and B on which the color gamut is mapped, and a combination of inks that reproduce the color represented by the data, that is, yellow, magenta, cyan, black, green, light cyan, and light magenta. The color separation data Y, M, C, K, G, LC, and LM corresponding to are obtained. In the present embodiment, this process is performed by using a three-dimensional LUT together with an interpolation operation as in the previous process. The γ correction J0004 performs gradation value conversion for each color data of the color separation data obtained by the post-processing J0003. Specifically, by using a one-dimensional LUT corresponding to the gradation characteristics of each color ink of the printer used in this system, conversion is performed so that the color separation data is linearly associated with the gradation characteristics of the printer. . Halftoning J0005 performs quantization that converts 8-bit color separation data Y, M, C, K, G, LC, and LM into 4-bit data. In this embodiment, 8-bit data is converted into 4-bit data using an error diffusion method. This 4-bit data is data serving as an index for indicating an arrangement pattern in the dot arrangement patterning process in the printing apparatus. Finally, print data is created by adding print control information to the print image data containing the 4-bit index data by print data creation processing J0006. The processing of the application and printer driver described above is performed by the CPU according to these programs. At that time, the program is read from the ROM or the hard disk and used, and the RAM is used as a work area when executing the processing.

  The recording apparatus performs dot arrangement patterning processing J0007 and mask data conversion processing J0008 regarding data processing. The dot arrangement patterning process J0007 performs dot arrangement for each pixel corresponding to an actual print image according to a dot arrangement pattern corresponding to 4-bit index data (tone value information) that is print image data. In this way, by assigning a dot arrangement pattern corresponding to the gradation value of each pixel represented by 4-bit data, dot on / off is defined in each of a plurality of areas in the pixel, Discharge data “1” or “0” is arranged in each area within one pixel. The 1-bit ejection data obtained in this way is subjected to a mask process by a mask data conversion process J0008. That is, the ejection data for each scan for completing the recording of the scanning region of the predetermined width by the recording head by a plurality of scans is generated by a process using a mask corresponding to each scan. The ejection data Y, M, C, K, G, LC, and LM for each scan are sent to the head drive circuit J0009 at an appropriate timing, whereby the recording head J0010 is driven and each ink is ejected according to the ejection data. Is done. Note that the above-described dot arrangement patterning process and mask data conversion process in the printing apparatus are executed under the control of the CPU that constitutes the control unit of the printing apparatus using a dedicated hardware circuit for them. Note that these processes may be performed by the CPU according to a program, and the above processes may be executed by a printer driver in a PC, for example, and the form of these processes is not limited in applying the present invention. Is clear.

  In this embodiment, an image forming apparatus using ink as a recording agent will be described. However, an image forming apparatus using an offset printing method, a gravure printing method, an electrophotographic printing method, or the like, for example, a printer using another recording agent such as toner. It is apparent that the present invention can be applied to a copying machine or the like except for the explanation specific to ink.

<Schematic Configuration of Mechanism Unit of Image Forming Apparatus>
A schematic configuration of a mechanism unit of an ink jet recording apparatus used as an image forming apparatus in the present embodiment will be described. The main body of the recording apparatus according to the present embodiment includes a paper feed unit, a paper transport unit, a carriage unit, a paper discharge unit, a cleaning unit, and an exterior unit that protects these parts and has a design from the role of each mechanism. The outline of these will be described below.

  FIG. 4 is a perspective view of a recording apparatus applied in this embodiment. 5 and 6 are diagrams for explaining the internal mechanism of the recording apparatus main body. FIG. 5 is a perspective view from the upper right portion, and FIG. 6 is a side sectional view of the recording apparatus main body. is there.

  When paper feeding is performed in the recording apparatus applied in the present embodiment, first, only a predetermined number of recording media in the paper feeding unit including the paper feeding tray M2060 is transferred to the nip part constituted by the paper feeding roller M2080 and the separation roller M2041. Sent. The sent recording medium is separated at the nip portion, and only the uppermost recording medium is conveyed. The recording medium sent to the paper transport unit is guided by the pinch roller holder M3000 and the paper guide flapper M3030, and is sent to the roller pair of the transport roller M3060 and the pinch roller M3070. A roller pair composed of a conveyance roller M3060 and a pinch roller M3070 is rotated by driving of the LF motor E0002, and the recording medium is conveyed on the platen M3040 by this rotation.

  When an image is formed on a recording medium in the carriage unit, the recording head H1001 (FIG. 7) is disposed at a target image forming position, and ink is ejected onto the recording medium in accordance with a signal from the electric substrate E0014. Although the detailed configuration of the recording head H1001 will be described later, in the recording apparatus of the present embodiment, a recording medium is scanned by the carriage M4000 in the column direction while recording is performed by the recording head H1001, and a recording medium is detected by the conveyance roller M3060. An image is formed on the recording medium by alternately repeating the sub-scan transported in the row direction.

  The recording medium on which the image has been finally formed is sandwiched between nips of the first paper discharge roller M3110 and the spur M3120 at the paper discharge unit, conveyed, and discharged to the paper discharge tray M3160.

  For the purpose of cleaning the recording head H1001 before and after image recording in the cleaning unit, if the pump M5000 is operated in a state where the cap M5010 is in close contact with the ink discharge port of the recording head H1001, it is unnecessary from the recording head H1001. Ink or the like is sucked. Further, by sucking the ink remaining in the cap M5010 with the cap M5010 opened, consideration is given to preventing the remaining ink from adhering and the subsequent adverse effects.

(Recording head configuration)
The configuration of the head cartridge H1000 applied in the present embodiment will be described below.

  The head cartridge H1000 in this embodiment has a recording head H1001, a means for mounting the ink tank H1900, and a means for supplying ink from the ink tank H1900 to the recording head, and is detachable from the carriage M4000. Mounted on.

  FIG. 7 is a diagram illustrating a state in which the ink tank H1900 is attached to the head cartridge H1000 applied in the present embodiment. The recording apparatus of the present embodiment forms an image with seven colors of ink of cyan, magenta, yellow, black, fourth, light cyan, and light magenta, and therefore the ink tank H1900 is also prepared for seven colors independently. Yes. As shown in the figure, each is detachable from the head cartridge H1000. The ink tank H1900 can be attached and detached while the head cartridge H1000 is mounted on the carriage M4000.

  FIG. 8 is an exploded perspective view of the head cartridge H1000. In the figure, a head cartridge H1000 includes a first recording element substrate H1100 and a second recording element substrate H1101, a first plate H1200, a second plate H1400, an electric wiring substrate H1300, a tank holder H1500, and a flow path forming member H1600. , Filter H1700, seal rubber H1800, and the like.

  The first recording element substrate H1100 and the second recording element substrate H1101 are Si substrates, and a plurality of recording elements (nozzles) for ejecting ink are formed on one side thereof by a photolithography technique. Electric wiring such as Al for supplying electric power to each recording element is formed by a film forming technique, and a plurality of ink flow paths corresponding to individual recording elements are also formed by a photolithography technique. Further, an ink supply port for supplying ink to the plurality of ink flow paths is formed to open on the back surface.

  FIG. 9 is an enlarged front view for explaining the configuration of the first recording element substrate H1100 and the second recording element substrate H1101. H2000 to H2600 are printing element rows (hereinafter also referred to as nozzle rows) corresponding to different ink colors. The first printing element substrate H1100 has a nozzle row H2000 supplied with cyan ink and a supply of magenta ink. The nozzle row for two colors is configured, that is, the nozzle row H2100 to be supplied and the nozzle row H2200 to which yellow ink is supplied. The second recording element substrate H1101 includes a nozzle row H2300 to which black ink is supplied, a nozzle row H2400 to which fourth ink is supplied, a nozzle row H2500 to which light cyan ink is supplied, and light magenta ink. The nozzle row for four colors of the nozzle row H2600 to be supplied is configured.

  Each nozzle row is composed of 768 nozzles arranged at an interval of 1200 dpi (dot / inch; reference value) in the conveyance direction of the recording medium, and ejects approximately 2 picoliters of ink droplets. The opening area at each nozzle outlet is set to about 100 square μm 2. Further, the first recording element substrate H1100 and the second recording element substrate H1101 are bonded and fixed to the first plate H1200. Here, the first recording element substrate H1100 and the second recording element substrate H1101 are attached. An ink supply port H1201 for supplying ink is formed.

  Further, a second plate H1400 having an opening is bonded and fixed to the first plate H1200, and the second plate H1400 includes the electric wiring substrate H1300, the first recording element substrate H1100, and the second recording element substrate H1100. The electric wiring substrate H1300 is held so that the recording element substrate H1101 is electrically connected.

  The electrical wiring substrate H1300 applies an electrical signal for ejecting ink from each nozzle formed on the first recording element substrate H1100 and the second recording element substrate H1101, and the first recording element substrate Electrical wiring corresponding to the H1100 and the second recording element substrate H1101, and an external signal input terminal H1301 for receiving an electrical signal from the recording apparatus main body located at the end of the electrical wiring. The external signal input terminal H1301 is positioned and fixed on the back side of the tank holder H1500.

  On the other hand, in a tank holder H1500 that holds the ink tank H1900, a flow path forming member H1600 is fixed by, for example, ultrasonic welding to form an ink flow path H1501 that communicates from the ink tank H1900 to the first plate H1200.

  A filter H1700 is provided at the end of the ink flow path H1501 engaged with the ink tank H1900 on the ink tank side so that dust can be prevented from entering from the outside. Further, a seal rubber H1800 is attached to the engaging portion with the ink tank H1900 so that ink can be prevented from evaporating from the engaging portion.

  Further, as described above, the tank holder portion including the tank holder H1500, the flow path forming member H1600, the filter H1700, and the seal rubber H1800, the first recording element substrate H1100, the second recording element substrate H1101, and the first plate. The head cartridge H1000 is configured by bonding the recording head unit H1001 including the H1200, the electric wiring substrate H1300, and the second plate H1400 by bonding or the like.

  In addition, as an ink discharge method of the recording head, for example, as an energy used for discharging the ink, an electrothermal converter that generates thermal energy for causing film boiling to the ink according to an electric signal (Recording element) may be used. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it corresponds to a sheet or liquid flow path in which liquid (ink) is held. By applying at least one drive signal that corresponds to the recorded information and gives a rapid temperature rise exceeding the nucleate boiling to the electrothermal transducer arranged in a manner, heat energy is generated in the electrothermal transducer, This is effective because film boiling occurs on the heat acting surface of the recording head, and as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. If this drive signal is in the form of a pulse, it is more preferable because bubbles can be grown and contracted promptly and appropriately, and liquid (ink) discharge having particularly excellent response can be achieved.

  As another form of the recording head by the ejection method, a nozzle forming substrate having a plurality of nozzles, a pressure generating element made of a piezoelectric material and a conductive material arranged opposite to the nozzles, and a periphery of the pressure generating element An on-demand ink jet recording head that includes ink satisfying the above requirements, displaces a pressure generating element by an applied voltage, and ejects a small droplet of ink from a nozzle.

  Further, the ink jet recording apparatus is not limited to the one in which the head and the ink tank are separated as described above, but may be one in which they are integrated so as not to be separated. The ink tank is integrated with the head so as to be separable or inseparable from the head and mounted on the carriage, and is provided at a fixed portion of the apparatus so that ink is supplied to the recording head via an ink supply member, for example, a tube. The thing of the form to supply may be sufficient. Further, when the ink tank is provided with a configuration for applying a preferable negative pressure to the recording head, a configuration in which an absorber is disposed in the ink storage portion of the ink tank, or a flexible ink storage bag and the same A form having a spring portion that applies a biasing force in the direction of expanding the internal volume can be employed.

  In addition to the serial recording method as described above, the recording apparatus may take the form of a line printer in which recording elements are aligned over a range corresponding to the entire width of the recording medium.

<Ink>
The color material of the ink used in the present invention may be a known color material such as a commonly used dye or pigment, or a newly synthesized color material, within the scope of the present invention. Can be appropriately selected and used. In particular, as a form of the present invention, it is preferable to use at least a dye as a coloring material. Since the dye is dissolved at the molecular level in the ink, when the ink is applied according to the present invention to glossy media such as glossy paper and glossy film that are frequently used for photo output in recent years, the coloring material is contained in the ink receiving layer. Because the surface condition of the recording and non-recording parts on the surface of the medium is maintained, the glossiness is not lost, and an image having a high texture comparable to the positive film of silver salt photography can be formed. This is a preferred form.

  The content of the color material contained in the ink is preferably 0.1 to 15% by mass with respect to the total mass of the ink. In addition, the color materials contained in the ink can be used alone or in combination of two or more. As for the color material used for the fourth ink, a single color material, a mixture of two or more color materials having similar hues, a mixture of color materials having yellow and cyan hues, etc. It can select suitably and use within the scope of the present invention.

  However, it is a feature of the present invention that the yellow, magenta, cyan, and fourth inks have color materials and ink compositions that satisfy the conditions 1 to 2 described above when the color is recorded on the recording medium. .

  As a particularly preferable form satisfying these conditions, it is preferable to use a dye, particularly an acid dye or a direct dye, as a colorant for yellow, magenta and cyan in the present invention. In particular, acid dyes and direct dyes can obtain good color on various recording media such as plain paper, glossy paper, coated paper, and special media with a coating layer or ink receiving layer on the surface, such as glossy film. Therefore, it can be suitably used in the present invention.

(Yellow, magenta and cyan ink)
Specific examples of acid dyes and direct dyes are shown below as examples of color materials for yellow, magenta, and cyan that can be used in the present invention, but the present invention is not limited to these.
-Color material for yellow ink C.I. I. Direct yellow: 8, 11, 12, 27, 28, 33, 39, 44, 50, 58, 85, 86, 87, 88, 89, 98, 100, 110, 132, 173, etc. I. Acid Yellow: 1, 3, 7, 11, 17, 23, 25, 29, 36, 38, 40, 42, 44, 76, 98, 99, etc. In addition, International Publication No. 99/43754, International Publication No. Compounds having a structure described in the pamphlet of 02/0881580.
-Color material for magenta ink C.I. I. Direct Red: 2, 4, 9, 11, 20, 23, 24, 31, 39, 46, 62, 75, 79, 80, 83, 89, 95, 197, 201, 218, 220, 224, 225, 226 227, 228, 229, 230, etc. C.I. I. Acid Red: 6, 8, 9, 13, 14, 18, 26, 27, 32, 35, 42, 51, 52, 80, 83, 87, 89, 92, 106, 114, 115, 133, 134, 145 158, 198, 249, 265, 289, etc. C.I. I. Food Red: 87, 92, 94, etc. C.I. I. Direct Violet 107 etc. In addition, it is described in JP2003-49100A, JP2002-371214A, JP2002-309133A, JP2002-309116A, and JP2002-309115A. A compound having a structure such as: a coloring material for cyan ink; I. Direct Blue: 1, 15, 22, 25, 41, 76, 77, 80, 86, 90, 98, 106, 108, 120, 158, 163, 168, 199, 226, 307, etc. C.I. I. Acid Blue: 1, 7, 9, 15, 22, 23, 25, 29, 40, 43, 59, 62, 74, 78, 80, 90, 100, 102, 104, 112, 117, 127, 138, 158 161, 203, 204, 221, 244, etc. In addition, it is described in JP 2002-327132 A, JP 2002-302623 A, JP 2002-294097 A, and WO 02/088256. A compound having a structure.

  Of the dyes described above, not only good color reproducibility is obtained, but also the reliability of the ink jet recording apparatus, such as hard clogging of the recording head, solubility in the ink liquid medium, and ink storage stability. In particular, for yellow, Acid Yellow 17, 23, Direct Yellow 86, 132, 173, International Publication No. 99/43754, International Publication No. 02/081580 For compounds and magenta, Acid Red 52, 289, Direct Violet 107, JP2003-49100, JP2002-371214, JP2002-309133, JP2002-309116, JP Compounds described in JP-A 2002-309115, general formula (I) Dyes represented by the general formula (II) in the form of a free acid, and Direct Blue 199, Acid Blue 9 for cyan, JP 2002-327132 A, JP 2002-302623 A, JP 2002-294097 A The compounds described in the gazette and the pamphlet of International Publication No. 02/088256 can be suitably used.

(4th ink)
Next, specific examples of the color material used for the fourth ink that can be used in the present invention are illustrated below, but the present invention is not limited to these. Further, as the color material used for the fourth ink, for example, the above-described color materials for yellow and cyan can be used in combination with the color material exemplified below. Alternatively, the above-mentioned mixture of yellow and cyan color materials can be appropriately mixed and used as the fourth color material for ink.
-Color material for the fourth ink C.I. I. Acid Green 1, 3, 5, 6, 9, 12, 15, 16, 19, 21, 25, 28, 81, 84, etc. C.I. I. Direct green 26, 59, 67 etc. C.I. I. Food Green 3 etc. C.I. I. Reactive Green 5, 6, 12, 19, 21 etc. C.I. I. Disperse green 6, 9, etc. (light ink)
The color material for light ink, that is, light cyan LC and light magenta LM, is selected as appropriate from known color materials such as commonly used dyes and pigments or newly synthesized color materials. Can be used.

(Black ink)
Specific examples of the black color material are illustrated below, but the present invention is not limited thereto.
-Color material for black ink C.I. I. Direct black: 17, 19, 22, 31, 32, 51, 62, 71, 74, 112, 113, 154, 168, 195, etc. C.I. I. Acid Black: 2, 48, 51, 52, 110, 115, 156, etc. C.I. I. Food Black 1, 2, etc. Carbon Black, etc. In addition, compounds having the structure described in International Publication No. 00/43451 pamphlet, etc.

  Examples of the carbon black include carbon black pigments such as furnace black, lamp black, acetylene black, and channel black. For example, Raven 7000, Ray Van 5750, Ray Van 5250, Ray Van 5000, Ray Van 3500, Ray Van 2000, Ray Van 1500, Ray Van 1250, Ray Van 1200, Ray Van 1190ULTRA-II, Ray Van 1170, Ray Van 1255 (above Colombia), Black Pearls L, Legal 400R, Legal 330R, Legal 660R, Mogu L, Monak ( Monarch) 700, Monak 800, Monak 880, Monak 900, Monak 1000, Mon 1100, Monak 1300, Monak 1400, Valcan XC-72R (made by Cabot), Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 ( (Degussa) 25, no. 33, no. 40, no. 47, no. 52, no. 900, no. 2300, MCF-88, MA600, MA7, MA8, MA100 (manufactured by Mitsubishi Chemical) or the like can be used. Further, magnetic fine particles such as magnetite and ferrite, titanium black and the like may be used as the black pigment.

(Dispersant)
When using the above-mentioned pigment, it is preferable to use a dispersant together. As the dispersant, those capable of stably dispersing the above pigment in an aqueous medium by the action of an anionic group are suitably used. Specific examples of the dispersant include, for example, a styrene-acrylic acid copolymer, a styrene-acrylic acid-alkyl acrylate copolymer, a styrene-maleic acid copolymer, a styrene-maleic acid-acrylic acid alkyl ester copolymer, Styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer, styrene -Maleic anhydride-maleic acid half ester copolymer or salts thereof are included. These dispersants preferably have a weight average molecular weight in the range of 1000 to 30000.

(Self-dispersing pigment)
As the coloring material, a pigment that can be dispersed in an aqueous medium without a dispersant by bonding an ionic group (anionic group) to the pigment surface, a so-called self-dispersing pigment can be used. An example is self-dispersing carbon black. Examples of the self-dispersing carbon black include those in which an anionic group is bonded to the surface of the carbon black.

  The ink used in the present invention is generally used in various image forming methods and image forming apparatuses in which the above-described color material is suitably used in the image forming method and image forming apparatus according to the present invention, such as powder and aqueous solution. It can be used after being processed using a commonly used technique. As an example, ink used in the ink jet recording apparatus according to the present invention will be described.

(Aqueous medium)
The ink used in the ink jet recording apparatus according to the present invention is generally used by dissolving or dispersing the color material used in the present invention in an aqueous medium mainly composed of water. As this aqueous medium, water alone or one containing water and a water-soluble organic solvent can be used.

  The water-soluble organic solvent is not particularly limited as long as it exhibits water solubility, and alcohol, polyhydric alcohol, polyglycol, glycol ether, nitrogen-containing polar solvent, sulfur-containing polar solvent, ureas, saccharides and these Any derivative or the like that is generally used as a solvent for ink-jet inks can be used without problems. These solvents are used for maintaining the moisture retention of the ink, improving the solubility and dispersibility of the coloring material, and penetrating the ink into the recording paper. These solvents can be used alone or in combination.

  In general, the content of the water-soluble organic solvent is preferably in the range of 1 to 50% by mass, more preferably in the range of 3 to 40% by mass with respect to the entire ink. The water content in the ink is preferably in the range of 30 to 95% by mass in order to maintain good dye solubility and ink ejection stability.

(Additive)
Further, in addition to the above components, the ink of the present invention includes a surfactant, a pH adjuster, a rust inhibitor, an antiseptic, an antifungal agent, an antioxidant, a reduction inhibitor, an evaporation accelerator, and a chelating agent as necessary. Various additives such as a water-soluble polymer may be contained.

  For example, as surfactants, fatty acid salts, higher alcohol sulfate esters, liquid fatty oil sulfate esters, alkylallyl sulfonates and other anionic surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, There are nonionic surfactants such as polyoxyethylene sorbitan alkyl esters, acetylene alcohol, and acetylene glycol, and one or more of these can be appropriately selected and used. Among the above-mentioned, acetylene alcohols and acetylene glycols can be preferably used in order to exhibit an effect excellent in permeability to plain paper. The amount used varies depending on the type of surfactant, but is preferably 0.01 to 5% by mass relative to the total amount of ink. At this time, the surface tension of the ink at 25 ° C. is preferably 10 mN / m (dyn / cm) or more, more preferably 20 mN / m or more, and the surface tension of 60 mN / m or less. It is preferable to determine the amount to be added. This is because, in the ink jet recording method used in the present invention, it is possible to effectively suppress the occurrence of so-called printing misalignment (deviation of the landing point of ink droplets) due to wetting of the nozzle tip.

  The ink is preferably adjusted to have a desired viscosity and pH in order to obtain good ejection characteristics in the ink jet recording apparatus.

<Recording medium>
The recording medium that can be used in the present invention is generally used as a special medium having a coating layer or an ink receiving layer on its surface, such as plain paper, glossy paper, coated paper, or glossy film. A recording medium can be used. Among these, a special medium having a hydrophilic porous particle layer, a porous polymer layer, etc. on a substrate is an example of a recording medium that can provide an image with higher vividness, contrast, and transparency. it can.

  In more detail, an example of a special medium as a recording medium used in the present invention will be described in detail. A coloring material such as a dye or a pigment is adsorbed on the fine particles forming the hydrophilic porous structure in the ink receiving layer, and at least this adsorbed. This is a recording medium on which an image is formed by a color material, and is particularly suitable when an ink jet method is used. Such a recording medium is preferably a so-called absorption type in which ink is absorbed by a gap formed in an ink receiving layer on a support.

  The absorption type ink receiving layer is constituted as a hydrophilic porous layer mainly composed of fine particles and containing a binder and other additives as required. Examples of fine particles include inorganic pigments such as silica, clay, talc, calcium carbonate, kaolin, alumina or alumina hydrate, diatomaceous earth, titanium oxide, hydrotalcite, zinc oxide, urea formalin resin, ethylene resin And organic pigments such as styrene resins, and one or more of these are used.

  Examples of suitable binders include water-soluble polymers and latex. For example, polyvinyl alcohol or a modified product thereof, starch or a modified product thereof, gelatin or a modified product thereof, gum arabic, carboxymethylcellulose, hydroxyethylcellulose, hydroxyprooylmethylcellulose and other cellulose derivatives, SBR latex, NBR latex, methylmethacrylate-butadiene Polymer latex, functional group-modified polymer latex, vinyl copolymer latex such as ethylene vinyl acetate copolymer, polyvinyl pyrrolidone, maleic anhydride or copolymer thereof, acrylate copolymer, etc. are used and necessary Depending on the situation, two or more kinds can be used in combination. In addition, additives can also be used. For example, a dispersant, a thickener, a pH adjuster, a lubricant, a fluidity modifier, a surfactant, an antifoaming agent, a mold release agent, a fluorescence enhancer, if necessary. Whitening agents, ultraviolet absorbers, antioxidants and the like are used.

  In the above embodiment, the green ink is added to support the extended color space, but there is also an application for reproducing the wide color space of the positive film for the purpose of adding the green ink.

FIG. 10 is a diagram in which the color gamut of the ink jet recording apparatus and the positive film is plotted on the a ^* b ^* plane in CIE-L ^* a ^* b ^* . In the figure, the solid color represents the color reproduction range of the ink jet printer, and the point represents the color reproduction range of the positive film. As is clear from the figure, in order to more effectively output the color reproduction of the positive film, the hue angle of the maximum saturation is 100 to 100 in the a ^* b ^* plane instead of the fourth ink of the above embodiment. It is preferable to use a fifth ink that is 130 degrees. The hue angle of the maximum saturation of the ink can be realized by appropriately selecting the above-described dye or by appropriately mixing cyan and yellow.

  Therefore, depending on whether the application is compatible with the extended color space or the reproduction of positive film, it is possible to reproduce the color space optimal for each application by replacing and mounting the fourth and fifth inks. Become.

FIG. 6 is a diagram schematically showing the relationship between lightness and saturation for explaining the selection or design conditions of ink colors basically employed in the present invention. FIG. 3 is a diagram schematically illustrating a relationship between an ink color reproduction region and an AdobeRGB color reproduction region that are basically employed in the present invention. 1 is a block diagram illustrating a configuration of a print system according to an embodiment of the present invention. 1 is a perspective view of a recording apparatus according to an embodiment of the present invention. FIG. 3 is a perspective view of a mechanism unit of the recording apparatus according to the embodiment of the invention. 1 is a cross-sectional view of a recording apparatus in an embodiment of the present invention. FIG. 5 is a perspective view illustrating a state where an ink tank is mounted on the head cartridge applied in the embodiment of the present invention. It is a disassembled perspective view of the head cartridge applied in the embodiment of the present invention. FIG. 3 is a front view showing a recording element substrate in a head cartridge applied in an embodiment of the present invention. It is the figure which showed the relationship between the color reproduction area of an inkjet printer and the color reproduction area of a positive film in 2nd Example.

Explanation of symbols

J0001 Application J0002 Pre-processing J0003 Post-processing J0004 γ correction J0005 Halftoning J0006 Print data creation processing J0007 Dot arrangement patterning processing J0008 Mask data conversion processing J0009 Head drive circuit J0010 Recording head M2041 Separation roller M2080 Paper feed roller M3000 Pinch roller Holder M3040 Platen M3060 Transport roller M3070 Pinch roller M3110 Paper discharge roller M3120 Spur M3160 Paper discharge tray M4000 Carriage M5000 Pump M5010 Cap E0002 LF motor E0014 Main substrate H1000 Head cartridge H1001 Recording head H1100 First recording element substrate H1101 Substrate H120 0 First plate H1201 Ink supply port H1300 Electrical wiring board H1301 External signal input terminal H1400 Second plate H1500 Tank holder H1501 Ink channel H1600 Channel forming member H1700 Filter H1800 Seal rubber H1900 Ink tank H2000 Cyan nozzle column H2100 Magenta nozzle column H2200 Yellow nozzle row H2300 Black nozzle row H2400 Fourth ink nozzle row H2500 Light cyan ink nozzle row H2600 Light magenta ink nozzle row

Claims (4)

An image forming method for forming an image based on pixel data using at least a yellow recording agent, a magenta recording agent, a cyan recording agent, and a fourth recording agent, wherein the color of CIE-L ^* a ^* b ^* In space, the color expressed on the recording medium by the fourth recording agent is lighter than the color reproduction region expressed on the recording medium by a combination of the yellow recording agent and the cyan recording agent. And an image forming method, wherein the hue angle of the maximum saturation in the color space is 130 to 160 degrees.   In the image forming method, the lightness and saturation are higher than the color reproduction region expressed on the recording medium by the combination of the yellow recording agent and the cyan recording agent, and the maximum saturation in the color space. A fifth recording agent having a hue angle of 100 to 130 degrees is used, and the fourth recording agent and the fifth recording agent are exchanged for use according to the type of image and the printing purpose. The image forming method described in 1. An image forming apparatus that forms an image based on pixel data using at least a yellow recording agent, a magenta recording agent, a cyan recording agent, and a fourth recording agent,
In the color space of CIE-L ^* a ^* b ^* , the color expressed on the recording medium by the fourth recording agent is a combination of the yellow recording agent and the cyan recording agent on the recording medium. An image forming apparatus characterized in that the brightness and saturation are higher than the color reproduction region expressed in (2), and the hue angle of the maximum saturation in the color space is 130 to 160 degrees.   In the image forming apparatus, the lightness and saturation are higher than the color reproduction region expressed on the recording medium by the combination of the yellow recording agent and the cyan recording agent, and the maximum saturation in the color space. A fifth recording agent having a hue angle of 100 to 130 degrees is used, and the fourth recording agent and the fifth recording agent are used interchangeably according to the type of image and the printing purpose. The image forming apparatus described in 1.

Images