JP2007313665A - Liquid droplet delivering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid droplet delivering apparatus which can suppress enlargement of the apparatus and can also suppress deterioration of an image quality. <P>SOLUTION: When preliminary delivering of color liquid droplets is carried out from nozzles that require the preliminary delivering, a processing liquid, the color liquid droplets as the preliminary delivering and black liquid droplets for recording black dots according to black pixels are delivered so as to overlap each other in a black region which is an object where the black dots according to the black pixels of image data are to be recorded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a droplet discharge device, and more particularly to a droplet discharge device that records dots corresponding to each pixel of image data by discharging droplets.

  Conventionally, as a droplet discharge device, a droplet discharge device such as an ink jet recording device that records dots corresponding to each pixel of image data by discharging a droplet such as ink from a nozzle is known.

  In such a droplet discharge device, the droplet in the nozzle thickens due to changes over time, or air is mixed into the nozzle, so that the droplet is not normally discharged from the nozzle. In order to suppress this, a recovery process is performed to remove the thickened droplets from the nozzles or the droplets mixed with air.

As an example of this recovery process, a technique is known in which droplets in a nozzle are sucked in a state where each nozzle is covered with a cap member during non-image formation. According to this technique, by removing the droplets from the nozzle portion, it is possible to remove the droplets with increased viscosity or air.
However, such a method of sucking droplets in the nozzle has a problem that a large amount of droplets is consumed by the suction of the droplets.

  As another example of the recovery processing, during non-image formation, the nozzle is moved to a liquid drain receiving portion provided in advance, and preliminary discharge unrelated to droplet discharge based on image data is transferred to the liquid drain receiving portion. A technique for removing thickened liquid droplets, air, and the like in the nozzle from the nozzle is known.

  However, in recent years, the number of nozzles provided in the droplet discharge device has been increasing with the demand for higher image quality. For this reason, in the technology for performing preliminary discharge to the drainage receiving portion as described above, it is necessary to provide a larger drainage receiving portion in the apparatus as the number of nozzles increases, and thus the enlargement of the droplet discharge device is a problem. There was a case.

As a technique that can cope with such a problem, for example, in Patent Document 1 and Patent Document 2, a color ink droplet is ejected to an area where dots are formed with black ink, thereby disposing a color ink in a nozzle that ejects the color ink. Removes thickened droplets and air.
According to this technique, since it is not necessary to provide the drainage receiving portion in the apparatus, it is possible to suppress an increase in the size of the droplet discharge apparatus.
Japanese Patent Laid-Open No. 1-174459 JP-A-9-216388

  However, in the above prior art, by discharging color ink droplets to the area where dots are formed with black ink, it is possible to remove thickened droplets or air-containing droplets from nozzles that discharge color inks. However, since the color ink droplets are ejected over the area where only black ink is ejected, an image with a hue different from the hue corresponding to the image data is formed, resulting in image quality degradation. there were.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a droplet discharge device capable of suppressing an increase in size of the droplet discharge device and suppressing deterioration in image quality.

  In order to solve the above problem, the droplet discharge device according to claim 1 records black dots corresponding to black pixels of image data by discharging a black droplet containing at least a black color material from a nozzle. A color liquid that records color dots corresponding to color pixels of a hue other than black in the image data by ejecting from the nozzle a color liquid droplet containing a black liquid droplet discharge head and a color material of a hue other than black at least A treatment liquid that thickens one or both of the black liquid droplets and the color liquid droplets or agglomerates the color material contained in one or both of the black liquid droplets and the color liquid droplets The processing liquid discharge head for discharging the liquid, the acquisition means for acquiring image data, and the image acquired by the acquisition means for the nozzles of the color droplet discharge head Determining means for determining whether or not preliminary discharge different from color droplet discharge based on data is necessary, and acquiring by the acquiring means when the determination means determines that preliminary discharge is necessary The processing liquid ejection head is controlled so that the processing liquid is ejected to the black area where black dots corresponding to the black pixels of the image data are recorded, and the preliminary ejection is necessary for the black area. The black liquid droplet ejection head is controlled so that a color liquid droplet is ejected from a nozzle determined to be present, and the black liquid droplet is ejected to the black region according to the black pixel. And a control means for controlling the discharge head.

  When the image data of the image to be recorded is acquired by the acquisition unit of the droplet discharge device according to the first aspect, the determination unit determines whether or not preliminary discharge of the color droplet is necessary. Preliminary discharge of color droplets is different from discharge of color droplets for recording color dots according to color pixels of a hue other than black in the image data acquired by the acquisition means, that is, recording of color dots The discharge is unrelated to the discharge of the color droplets for performing the above. The determination by the determination means may be performed by determining, for example, the nozzles of the color droplet discharge head that have not been discharged for a predetermined time or more after the previous color droplet discharge. The discrimination by this discrimination means is a nozzle that has not been ejected for a predetermined time or more since the last ejection of the color droplets among the nozzles of the color droplet ejection head, and can be recorded by this nozzle. In addition, a nozzle in which the pixel in the image data acquired by the acquisition unit is not a color pixel may be determined.

  When it is determined by the determination unit that preliminary ejection is necessary, the control unit applies a black dot corresponding to the black pixel among the pixels of the image data acquired by the acquisition unit to the black region to be recorded. The processing liquid discharge head, the color liquid droplet discharge head, and the black liquid droplet discharge head are controlled so that the processing liquid, the color liquid droplet, and the black liquid droplet are discharged. The black pixel is a pixel for recording a black dot among the pixels of the image data acquired by the acquisition unit.

  In this case, as described in claim 2, the control unit can perform printing with a nozzle that has been determined by the determination unit that preliminary ejection is necessary, among the pixels of the image data acquired by the acquisition unit. A search means for searching for a pixel whose pixel is a black pixel is included, and the black area can be an area in which black dots corresponding to the black pixel searched by the search means are recorded.

  The control means increases the viscosity of one or both of the black droplets and the color droplets in the black region, or a processing liquid that agglomerates the color material contained in one or both of the black droplets and the color droplets. In addition to controlling the processing liquid ejection head so that the liquid droplets are ejected, and controlling the color liquid droplet ejection head so that the color liquid droplets are ejected from the nozzles determined to require preliminary ejection in the black region The black droplet discharge head is controlled so that black droplets corresponding to the black pixels among the pixels of the image data acquired by the acquisition unit are discharged to the black region.

For this reason, the processing liquid and the color discharged from the nozzles that require preliminary discharge are applied to the black region to which black droplets corresponding to the black pixels among the pixels of the image data acquired by the acquisition unit are to be discharged. A droplet and a black droplet corresponding to the black pixel are ejected in an overlapping manner.
The discharge order may be such that at least the black liquid droplets are discharged after the processing liquid is discharged. Preferably, the processing liquid, the color liquid droplets, and the black liquid droplets are discharged in this order.

  As described above, when performing preliminary discharge of color liquid droplets from a nozzle that requires preliminary discharge, the processing liquid and the preliminary discharge are applied to the black region where black dots corresponding to the black pixels of the image data are recorded. Since the color liquid droplets and the black liquid droplets for recording black dots corresponding to the black pixels can be ejected so that at least one of the ejected black liquid droplets and the color liquid droplets is a treatment liquid Due to this effect, it is possible to suppress the protrusion from the region that should be originally formed, and to suppress the deterioration of the image quality. In addition, since a color droplet as a preliminary discharge is discharged to a black region where black dots corresponding to the black pixels of the image data are recorded, a drainage receiving portion for performing the preliminary discharge as in the prior art Therefore, it is possible to efficiently perform image recording processing while suppressing an increase in the size of the droplet discharge device.

  Therefore, it is possible to provide a droplet discharge device that can suppress an increase in size of the droplet discharge device and can suppress deterioration in image quality.

  The droplet discharge device according to claim 3 is the droplet discharge device according to claim 1 or 2, wherein in the black region, a plurality of black dots corresponding to black pixels of image data are continuously recorded. Can be the area to be.

  In this way, by setting the black area as an area where a plurality of black dots corresponding to the black pixels of the image data are continuously recorded, preliminary discharge of color liquid droplets from nozzles that require preliminary discharge in the black area is performed. It is possible to suppress the deterioration of the image quality of the black area due to the execution.

  The droplet discharge device according to claim 4 is the droplet discharge device according to any one of claims 1 to 3, wherein an amount of the color droplet discharged to the black region is the black region. It is preferable that the amount be less than the amount of black droplets discharged on the surface. In this way, by reducing the amount of color droplets ejected to the black region from the amount of black droplets ejected to the black region, image quality deterioration due to the color droplets ejecting to the black region is reduced. Can be suppressed.

  The droplet discharge device according to claim 5 is the droplet discharge device according to any one of claims 1 to 4, wherein a surface tension of the color droplet is 40 mN / m or less. preferable. If the surface tension of the color droplets at 23 ° C. is 40 mN / m or less, compared with the case where the surface tension is larger than 40 mN / m, the color droplets onto the recording medium when the color droplets are ejected onto the black area are recorded. The penetration rate can be increased. For this reason, it is possible to suppress deterioration in image quality due to discharge of color droplets in the black region.

  A droplet discharge device according to claim 6, wherein a black droplet discharge head that records black dots corresponding to black pixels of image data by discharging black droplets containing at least a black color material from a nozzle; By discharging cyan color liquid droplets from the nozzles, a cyan liquid discharge head that records cyan dots according to the cyan pixels of the image data, and by discharging magenta color liquid droplets from the nozzles, A cyan liquid discharge head that records magenta dots corresponding to magenta pixels of image data and a yellow color droplet corresponding to yellow pixels of image data are recorded by discharging yellow color droplets from the nozzles. Yellow liquid discharge head, cyan color liquid droplets, magenta color liquid droplets, and yellow color liquid liquid A processing liquid discharge head for discharging a processing liquid for thickening each of the above, or for aggregating the color materials contained in the cyan color liquid droplets, the magenta color liquid droplets, and the yellow color liquid droplets; Image data acquired by the acquisition means for acquiring image data, nozzles included in the cyan liquid discharge head, nozzles included in the magenta liquid discharge head, and nozzles included in the yellow liquid discharge head Determining means for determining whether or not preliminary discharge different from color droplet discharge based on the image is required, and an image acquired by the acquisition means when the determination means determines that preliminary discharge is required Of each pixel of data, a pixel that can be recorded by the nozzle that requires preliminary ejection is searched for a pixel that is a black pixel, and according to the searched black pixel The processing liquid ejection head is controlled so that the processing liquid is ejected to a black area where black dots are to be recorded, and the cyan color droplet and the magenta color liquid droplet are applied to the black area. And a cyan liquid discharge head, the magenta liquid discharge head, and control means for controlling the yellow liquid discharge head so that the yellow color liquid droplets are discharged.

  The liquid droplet ejection apparatus according to claim 6 is capable of recording with a nozzle that requires preliminary ejection among the pixels of the image data acquired by the acquisition means when the determination means determines that preliminary ejection is required. A pixel that is a black pixel is searched, and the processing liquid discharge head is controlled so that the black liquid corresponding to the searched black pixel is recorded, and the processing liquid is discharged to the black area. The cyan liquid discharge head, the magenta liquid discharge head, and the yellow liquid so that the cyan color liquid droplet, the magenta color liquid droplet, and the yellow color liquid droplet are discharged to a black region. Control the ejection head.

  As described above, when preliminary discharge of color droplets is required, yellow, magenta, and cyan color droplets are overlapped without discharging black droplets in an area where black dots are recorded. It is possible to provide a droplet discharge device that can suppress the enlargement of the droplet discharge device and suppress the deterioration of the image quality while expressing black color by discharging, and suppress the consumption of the black droplet. be able to.

  The droplet discharge device according to claim 7 is the droplet discharge device according to claim 6, wherein the control unit records a black dot corresponding to the searched black pixel in the black region. Since the black droplet discharge head can be controlled, it is possible to further suppress the image quality deterioration in the black region.

  The droplet discharge device according to claim 8 is the droplet discharge device according to any one of claims 1 to 7, wherein the coloring material can be a pigment or a dye.

  According to the droplet discharge device of the present invention, the processing liquid, the color droplet as the preliminary discharge, and the black pixel corresponding to the black region on which the black dot corresponding to the black pixel of the image data is recorded. The black droplets for recording the black dots are ejected, so that it is possible to provide a droplet ejection device that can suppress an increase in size of the droplet ejection device and also can suppress deterioration in image quality. can get.

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

  As shown in FIG. 1, a paper feed tray 16 is provided at a lower portion in a casing 14 of an ink jet recording apparatus 12 as a liquid droplet ejection apparatus of the present invention, and the recording stacked in the paper feed tray 16 is performed. The recording medium P such as paper can be taken out one by one by the pickup roll 18. The removed recording medium P is transported by a plurality of transport roller pairs 20 constituting a predetermined transport path 22.

  Above the paper feed tray 16, an endless transport belt 28 stretched around a drive roll 24 and a driven roll 26 is disposed. A recording head 30 as a recording head of the present invention is disposed above the conveyor belt 28 and faces the flat portion 28F of the conveyor belt 28. This opposed region is an ejection region SE from which ink droplets as droplets used in the droplet ejection apparatus of the present invention are ejected from the recording head 30. The recording medium P transported along the transport path 22 is held by the transport belt 28 and reaches the ejection region SE, and ink droplets corresponding to image data are ejected from the recording head 30 while facing the recording head 30. As a result, dots corresponding to each pixel of the image data are recorded.

  Note that by rotating the recording medium P while being held by the conveyance belt 28, it is possible to perform image recording by so-called multi-pass by passing the recording medium P a plurality of times in the ejection region SE. Assume that an image is recorded in one pass.

For example, the transport belt 28 is made of a semiconductive polyimide material (for example, a surface resistance value of 10 ¹⁰ to 10 ¹³ Ω / m ² and a volume resistance value of 10 ⁹ to 10 ¹² Ω · cm), a thickness of 75 μm, What was shape | molded in width 380mm and peripheral length 1000mm can be used. Moreover, as the drive roll 24 and the driven roll 26, a SUS roll with a diameter of 50 mm can be used as an example.

  Further, the means for rotating the recording medium P is not limited to the conveyance belt 28. For example, the recording medium (recording medium P) may be sucked and held on the outer periphery of a cylindrical or columnar conveying roller and rotated. However, when the conveyor belt 28 is used as in the present embodiment, the flat portion 28F is formed, and therefore the recording head 30 can be disposed corresponding to the flat portion 28F.

  The recording head 30 discharges a processing liquid (H), which will be described later in detail, having the property of thickening ink droplets in the width direction of the recording medium P (direction perpendicular to the transport direction) or aggregating the color material contained in the ink droplets. A plurality of nozzles for ejecting ink droplets in the width direction of the recording medium P (direction orthogonal to the transport direction), and a long inkjet recording head 32H in which a plurality of nozzles are arranged, By ejecting ink droplets from each nozzle to the recording medium P, long yellow (Y), magenta (M), and magenta (M) for recording dots corresponding to each pixel of the image data on the recording medium P. Four ink jet recording heads 32Y, ink jet recording head 32M, ink jet recording head 32C, and ink corresponding to four colors of ink of cyan (C) and black (K) And the jet recording head 32K, a total of five ink jet recording head are arranged along the conveying direction of, and is recordable in a color image.

  Of the inks as droplets used in the present invention, an ink containing a black color material is appropriately referred to as a black ink, and an ink containing a color material exhibiting a hue other than the black hue is appropriately colored. This is called ink.

  Each of the inkjet recording head 32H, the inkjet recording head 32Y, the inkjet recording head 32M, the inkjet recording head 32C, and the inkjet recording head 32K has a so-called direction in which the length of the nozzle arrangement direction is orthogonal to the conveyance direction of the recording medium P, so-called. It is provided to be longer than the paper width.

  In the present embodiment, a long inkjet recording head 32H having a configuration in which a plurality of nozzles for discharging a processing liquid are arranged, and a configuration in which a plurality of nozzles for discharging ink droplets are arranged. A long yellow (Y), magenta (M), cyan (C), and black (K) ink jet recording head 32Y, an ink jet recording head 32M, an ink jet recording head 32C, and an ink jet recording head 32K; Are arranged along the conveyance direction of the recording medium P, and a full-color image can be recorded. However, the number of the inkjet recording heads 32 is not limited to five.

  The recording head 30 may be fixed in a direction orthogonal to the conveyance direction of the recording medium P (hereinafter referred to as a paper width direction as appropriate), but can be moved in the paper width direction as necessary. It may be configured. In this way, it is possible to record an image with higher resolution by multipass image recording.

  As shown in an enlarged view 33 around the nozzles in FIG. 2B, a plurality of ink jet recording heads 32H, ink jet recording heads 32Y, ink jet recording heads 32M, ink jet recording heads 32C, and ink jet recording heads 32K constituting the recording head 30. Each of the nozzles 33 </ b> B for discharging the treatment liquid or ink droplets is arranged in a plurality in the paper width direction of the recording medium P. Each nozzle 33B communicates with an ink pressure chamber 33C. In the ink pressure chamber 33C, a piezoelectric element 33D such as a piezo is provided in contact with the ink pressure chamber 33C. As is well known, the piezoelectric element 33D has a property that its shape changes when a voltage is applied. By applying pressure to the ink pressure chamber 33C using this shape change, the piezoelectric element 33D The processing liquid or ink droplets are ejected to record dots on the recording medium P.

  At this time, as shown in FIGS. 2A and 2C, by controlling the voltage applied to the piezoelectric element 33D, that is, the drive waveform, the drive voltage, and the like, a large drop of ink from the nozzle 33B (FIG. 2). (See (B)), the amount of ink droplets to be ejected by controlling the ejection of small ink droplets from the nozzle 33B (see FIG. 2D), the prohibition of dot formation, or the ejection of medium ink droplets, etc. Each amount of the processing liquid can be controlled.

  In the present embodiment, the case where ink droplets are ejected using the piezoelectric element 33D will be described. However, the present invention is not limited to such a form. For example, heat is applied to the ink in the ink pressure chamber 33C. Therefore, it is possible to apply a known method such as a so-called thermal method for controlling the size of dots recorded by ink droplet ejection, that is, the amount of ink droplets ejected.

  As shown in FIG. 3, a charging roll 36 is disposed on the upstream side of the recording head 30. The charging roll 36 is driven while sandwiching the conveyance belt 28 and the recording medium P with the driven roll 26, and is between a pressing position for pressing the recording medium P against the conveyance belt 28 and a separation position separated from the conveyance belt 28. Can be moved. At the pressing position, a predetermined potential difference is generated between the grounded driven roll 26 and the recording medium P can be charged and electrostatically attracted to the transport belt 28.

As the charging roll 36, for example, a roll having a diameter of 14 mm, in which conductive carbon is coated on the surface of silicone rubber and the volume resistance value is adjusted to about 10 ⁶ to 10 ⁷ Ω · cm, can be used.

  A registration roll (not shown) is provided further upstream than the charging roll 36, and the recording medium P is aligned before reaching the space between the conveyance belt 28 and the charging roll 36.

  A peeling plate 40 is disposed on the downstream side of the recording head 30, and the recording medium P can be peeled from the transport belt 28. As the peeling plate 40, for example, an aluminum plate having a thickness of 0.5 mm, a width of 332 Mm, and a length of 100 mm can be used.

  The peeled recording medium P is conveyed by a plurality of discharge roller pairs 42 constituting a discharge path 44 on the downstream side of the peeling plate 40, and discharged to a paper discharge tray 46 provided at the upper part of the housing 14.

  Below the peeling plate 40, a cleaning roll 48 capable of sandwiching the conveying belt 28 with the driving roll 24 is disposed, and the surface of the conveying belt 28 is cleaned.

  A reversing path 52 composed of a plurality of reversing roller pairs 50 is provided between the paper feed tray 16 and the conveying belt 28, and the recording medium P having an image recorded on one side is reversed to the conveying belt 28. By holding it, image recording on both sides of the recording medium P can be easily performed.

  Between the conveyor belt 28 and the paper discharge tray 46, as an ink tank, a tank 54H for storing processing liquid, an ink tank 54Y for storing each of the four colors of ink, an ink tank 54M, an ink tank 54C, and Each of the ink tanks 54K is provided. The processing liquid stored in the tank 54H is supplied to the ink jet recording head 32H through an ink supply pipe (not shown). Similarly, the processing liquid is stored in each of the ink tank 54Y, the ink tank 54M, the ink tank 54C, and the ink tank 54K. The ink is supplied to the ink jet recording head 32Y, the ink jet recording head 32M, the ink jet recording head 32C, and the ink jet recording head 32K through an ink supply pipe (not shown).

  The ink used in the present invention, which is stored in each of the ink tank 54Y, the ink tank 54M, the ink tank 54C, and the ink tank 54K, contains at least a coloring material such as a dye or a pigment. It contains an organic solvent and a surfactant, and may contain other components as necessary.

  The coloring material used in the ink may be either a dye or a pigment, but one or more pigments are particularly preferable. This is considered to be because the pigment is more likely to aggregate when mixed with the treatment liquid than the dye. In particular, since there is a high demand for black images frequently used for characters in offices in recent years, it is preferable to use carbon black, which is a black pigment excellent in water resistance and light resistance of images, for black (black) ink. Among the pigments, a pigment in which the pigment is dispersed with a polymer dispersant, a self-dispersible pigment, a pigment coated with a resin, and a polymer graft pigment are preferable.

  As the pigment used in the present invention, either an organic pigment or an inorganic pigment can be used. Examples of the black pigment include carbon black pigments such as furnace black, lamp black, acetylene black, and channel black. In addition to black, cyan, magenta and yellow primary pigments, special color pigments such as red, green, blue, brown and white, metallic luster pigments such as gold and silver, colorless or light body pigments, plastic pigments, etc. May be used. In addition, particles having silica or alumina, polymer beads, or the like as a core, and dyes or pigments fixed on the surface thereof, insoluble lakes of dyes, colored emulsions, colored latexes, and the like can also be used as pigments. Furthermore, a pigment newly synthesized for the present invention may be used.

  Specific examples of the pigment, Raven7000, Raven5750, Raven5250, Raven5000ULTRAII, Raven3500, Raven2500ULTRA, Raven2000, Raven1500, Raven1255, Raven1250, Raven1200, Raven1190ULTRAII, Raven1170, Raven1080ULTRA, Raven1060ULTRA, Raven790ULTRA, Raven780ULTRA, Raven760ULTRA (or, Columbian Carbon Manufactured by Co., Ltd.), Regal 400R, Regal 330R, Regal 660R, Mogu L, Monarch 700, Monarch 800, Monarch 880, Monarch 9 00, Monarch1000, Monarch 1100, Monarch 1300, Monarch 1400 (above, manufactured by Cabot), Color Black FW1, Color Black FW2, Color Black FW2V, Color Black 18, Color Black 150, Color Black , Printex 35, Printex U, Printex V, Printex 140U, Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 25, no. 33, no. 40, no. 47, no. 52, no. 900, no. 2300, MCF-88, MA600, MA7, MA8, MA100 (above, manufactured by Mitsubishi Chemical Corporation) and the like can be used, but are not limited thereto. As the black pigment, magnetic fine particles such as magnetite and ferrite, titanium black, and the like may be used.

  The pigment that can be self-dispersed in water used in the present invention refers to a pigment that has many water-solubilizing groups on the pigment surface and can be stably dispersed in water without the presence of a polymer dispersant. Specifically, it can be self-dispersed in water by subjecting ordinary so-called pigments to surface modification treatments such as acid / base treatment, coupling agent treatment, polymer graft treatment, plasma treatment, oxidation / reduction treatment, etc. Pigments are obtained.

  Examples of the pigment that can be self-dispersed in water include a pigment obtained by subjecting the above pigment to surface modification treatment, as well as Cab-o-jet-200, Cab-o-jet-250, Cab- o-jet-260, Cab-o-jet-270, Cab-o-jet-300, IJX-444, IJX-55, Microjet Black CW-1, CW-2 manufactured by Orient Chemical Co., and Nippon Shokubai Co., Ltd. Commercially available self-dispersing pigments such as self-dispersing pigments sold by

Furthermore, in the present invention, it is also possible to use a polymer graft pigment as the pigment as the color material used in the first liquid. The polymer graft pigment refers to one in which an organic compound such as a polymer is chemically bonded to the pigment surface.

  Examples of cyan pigments include C.I. I. Pigment Blue-1, -2, -3, -15, -15: 1, -15: 2, -15: 3, -15: 4, -16, -22, -60, and the like. It is not limited.

  Examples of magenta pigments include C.I. I. Pigment Red-5, -7, -12, -48, -48: 1, -57, -112, -122, -123, -146, -168, -184, -202, and the like. It is not limited.

Further, examples of yellow pigments include C.I. I. Pigment Yellow-1, -2, -3, -12, -13, -14, -16, -17, -73, -74, -75, -83, -93, -95, -97, -98, -114, -128, -129, -138, -151, -154, -180, and the like, but are not limited thereto.
Further, as each color material, a so-called capsule dye / pigment in which the color material is encapsulated with various resins may be used.

On the other hand, as the dye used in the present invention, either a water-soluble dye or a disperse dye can be used.
Specific examples of water-soluble dyes include C.I. I. Direct Black-2, -4, -9, -11, -17, -19, -22, -32, -80, -151, -154, -168, -171, -194, -195, C.I. I. Direct Blue-1, -2, -6, -8, -22, -34, -70, -71, -76, -78, -86, -112, -142, -165, -199, -200, -201, -202, -203, -207, -218, -236, -287, -307, C.I. I. Direct Red-1, -2, -4, -8, -9, -11, -13, -15, -20, -28, -31, -33, -37, -39, -51, -59, -62, -63, -73, -75, -80, -81, -83, -87, -90, -94, -95, -99, -101, -110, -189, -227, C.I. I. Direct Yellow-1, -2, -4, -8, -11, -12, -26, -27, -28, -33, -34, -41, -44, -48, -58, -86, -87, -88, -132, -135, -142, -144, -173, C.I. I. Food Black-1, -2, C.I. I. Acid Black-1, -2, -7, -16, -24, -26, -28, -31, -48, -52, -63, -107, -112, -118, -119, -121, -156, -172, -194, -208, C.I. I. Acid Blue-1, -7, -9, -15, -22, -23, -27, -29, -40, -43, -55, -59, -62, -78, -80, -81, -83, -90, -102, -104, -111, -185, -249, -254, C.I. I. Acid Red-1, -4, -8, -13, -14, -15, -18, -21, -26, -35, -37, -52, -110, -144, -180, -249, -257, -289, C.I. I. Acid Yellow-1, -3, -4, -7, -11, -12, -13, -14, -18, -19, -23, -25, -34, -38, -41, -42, -44, -53, -55, -61, -71, -76, -78, -79, -122 and the like.

  Specific examples of the disperse dye include C.I. I. Disperse Yellow-3, -5, -7, -8, -42, -54, -64, -79, -82, -83, -93, -100, -119, -122, -126, -160, -184: 1, -186, -198, -204, -224, C.I. I. Disperse Orange-13, -29, -31: 1, -33, -49, -54, -66, -73, -119, -163, C.I. I. Disperse Red-1, -4, -11, -17, -19, -54, -60, -72, -73, -86, -92, -93, -126, -127, -135, -145, -154, -164, -167: 1, -177, -181, -207, -239, -240, -258, -278, -283, -311, -343, -348, -356, -362, C. I. Disperse Violet-33, C.I. I. Disperse Blue-14, -26, -56, -60, -73, -87, -128, -143, -154, -165, -165: 1, -176, -183, -185, -201,- 214, -224, -257, -287, -354, -365, -368, C.I. I. Disperse Green-6: 1, -9 etc. are mentioned.

  The color material used in the present invention is preferably contained in the range of 1 to 15% by mass, more preferably in the range of 2 to 10% by mass with respect to the total mass of the ink. When the amount of the color material in the ink is less than 1% by mass, a sufficient optical density may not be obtained, and when the amount of the color material is more than 15% by mass, the liquid ejection characteristics are unstable. It may become.

In the present invention, it is preferable to use a water-soluble organic solvent as a material for improving the moisture retention performance and adjusting the liquid viscosity in the ink.
Examples of the water-soluble organic solvent include polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, butylene glycol, triethylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, glycerin, Nitrogen-containing solvents such as pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, triethanolamine, alcohols such as ethanol, isopropyl alcohol, butyl alcohol, benzyl alcohol, or thiodiethanol, thiodiglycerol, sulfolane, dimethylsulfur Sulfur-containing solvents such as oxide, propylene carbonate, ethylene carbonate and the like can be used, but are not limited thereto.

  The water-soluble organic solvent used in the present invention may be used alone or in combination of two or more. The water-soluble organic solvent is preferably included in the range of 1 to 60% by mass, and more preferably in the range of 5 to 40% by mass with respect to the total mass of the ink.

Normally, water is used for the ink, and this water can be ion exchange water, distilled water, pure water, ultrapure water, or the like.
The content of water contained in the ink is preferably in the range of 20 to 80% by mass, particularly in the range of 30 to 60% by mass. If it is less than 20% by mass, the ejection stability may be lowered, and ejection may not be performed normally. Moreover, when it exceeds 80 mass%, it may be inferior in long-term storage stability.

  The liquid viscosity of the ink is preferably in the range of 1 to 15 mPa · s. If the viscosity is less than 1 moa · s, the thickening on the recording medium may not be sufficient and good image quality may not be obtained, and the ejection stability may be impaired. On the other hand, if it exceeds 15 mPa · s, the ejection stability may not be sufficient, and image omission and blurring may occur.

  In addition, the ink contains water-soluble resins and emulsions to amplify the effect of improving image density, bleeding, intercolor bleeding, and image uniformity, and to adjust clogging, ejection response / ejection stability, and storage stability. Self-dispersing fine particles and water-insoluble polymer substances can also be added. In particular, when the ink contains a water-soluble resin, the effect of improving the image quality is increased. This is because the addition of water-soluble resin assists the networking of the color materials and facilitates the color material to have a three-dimensional structure in the ink. This is presumed to be amplified. In addition, since the network structure can be maintained on the recording medium even after an image is formed by adding a water-soluble resin, an image having excellent fixability and abrasion resistance can be provided.

  As the water-soluble resin, a compound having a hydrophilic structure part and a hydrophobic structure part can be effectively used, and specifically, a condensation polymer and an addition polymer are exemplified. Examples of the condensation polymer include polyester polymers, and examples of the addition polymer include addition polymers of monomers having an α, β-ethylenically unsaturated group. In addition, as the addition polymer, for example, a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group and a monomer having an α, β-ethylenically unsaturated group having a hydrophobic group are copolymerized as appropriate. Things are used. Furthermore, a homopolymer of a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group can also be used.

  Examples of the monomer having an α, β-ethylenically unsaturated group having a hydrophilic group include monomers having a carboxyl group, a sulfonic acid group, a hydroxyl group, a phosphoric acid group, such as acrylic acid, methacrylic acid, crotonic acid, and itaconic acid. , Itaconic acid monoester, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, vinyl sulfonic acid, styrene sulfonic acid, sulfonated vinyl naphthalene, vinyl alcohol, acrylamide, methacryloxyethyl phosphate, bismethacryloxyethyl phosphate Methacrylooxyethyl phenyl acid phosphate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate and the like.

  On the other hand, as a monomer having an α, β-ethylenically unsaturated group having a hydrophobic group, styrene derivatives such as styrene, α-methylstyrene, vinyltoluene, vinylcyclohexane, vinylnaphthalene, vinylnaphthalene derivatives, alkyl acrylate esters, Examples include acrylic acid phenyl ester, methacrylic acid alkyl ester, methacrylic acid phenyl ester, methacrylic acid cycloalkyl ester, crotonic acid alkyl ester, itaconic acid dialkyl ester, and maleic acid dialkyl ester.

The copolymer obtained by copolymerizing the monomer having a hydrophilic group and a hydrophobic group may have any structure such as a random, block, and graft copolymer.
Examples of preferred copolymers include styrene-styrene sulfonic acid copolymers, styrene-maleic acid copolymers, styrene-methacrylic acid copolymers, styrene-acrylic acid copolymers, vinyl naphthalene-maleic acid copolymers. , Vinyl naphthalene-methacrylic acid copolymer, vinyl naphthalene-acrylic acid copolymer, alkyl acrylate ester-acrylic acid copolymer, alkyl methacrylate-methacrylic acid, styrene-alkyl methacrylate-methacrylic acid copolymer Styrene-acrylic acid alkyl ester-acrylic acid copolymer, styrene-methacrylic acid phenyl ester-methacrylic acid copolymer, styrene-methacrylic acid cyclohexyl ester-methacrylic acid copolymer, and the like.

  A monomer having a polyoxyethylene group or a hydroxyl group may be appropriately copolymerized with these copolymers. In addition, in order to increase the affinity with the pigment having an acidic functional group on the surface and improve the dispersion stability, a monomer having a cationic functional group such as N, N-dimethylaminoethyl methacrylate, N, N-dimethylamino Ethyl acrylate, N, N-dimethylaminomethacrylamide, N, N-dimethylaminoacrylamide, N-vinylpyrrole, N-vinylpyridine, N-vinylpyrrolidone, N-vinylimidazole, and the like may be copolymerized as appropriate.

  Polystyrene sulfonic acid, polyacrylic acid, polymethacrylic acid, polyvinyl sulfonic acid, polyalginic acid, polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymer, formalin condensate of naphthalene sulfonic acid, polyvinyl pyrrolidone, polyethyleneimine, polyamine , Polyamides, polyvinyl imidazoline, aminoalkyl acrylate / acrylamide copolymer, chitosan, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid amide, polyvinyl alcohol, polyacrylamide, carboxymethylcellulose, carboxyethylcellulose Cellulose derivatives such as cellulose, polysaccharides and their derivatives can also be used effectively.

  Although not particularly limited, the hydrophilic group of the water-soluble resin is preferably a carboxylic acid or a salt of a carboxylic acid. This is considered to be because the degree of aggregation of the color material on the recording medium is appropriate particularly when carboxylic acid is used for the hydrophilic group.

Among these water-soluble resins, a copolymer having a hydrophilic group as an acidic group is preferably used in the form of a salt with a basic compound in order to enhance water solubility.
Compounds that form salts with these polymers include alkali metals such as sodium, potassium, and lithium; aliphatic amines such as monomethylamine, dimethylamine, and triethylamine; monomethanolamine, monoethanolamine, diethanolamine, and triethanol Alcohol amines such as amine and diisopropanolamine; ammonia;

  Preferably, basic compounds of alkali metals such as sodium, potassium and lithium are used. This is presumably because alkali metals are strong electrolytes and have the effect of promoting dissociation of hydrophilic groups.

The neutralization amount of the water-soluble resin is more preferably 60% or more neutralized with respect to the acid value of the copolymer, and still more preferably 80% or more of the acid value of the copolymer. It is to be united.
These water-soluble resins may be used alone or in combination of two or more.

  In addition, examples of the ink used in the present invention include polyethyleneimine, polyamines, polyvinylpyrrolidone, polyethylene glycol, cellulose derivatives such as methylcellulose, ethylcellulose, carboxyethylcellulose, glucose, fructose, mannitol, D-sorbitol, dextran, xanthan gum, card Polysaccharides such as orchid, cycloamylose and maltitol and derivatives thereof, other polymer emulsions, cyclodextrins, macrocyclic amines, dendrimers, crown ethers, urea and derivatives thereof, acetamide and the like can be used.

  Moreover, you may contain antioxidant, an antifungal agent, a electrically conductive agent, a ultraviolet absorber, a chelating agent etc. as needed. Examples of the chelating agent include ethylenediaminetetraacetic acid (EDTA), iminodiacetic acid (IDA), ethylenediaminedi (o-hydroxyphenylacetic acid) (EDDDHA), nitrilotriacetic acid (NTA), dihydroxyethylglycine (DHEG), trans -1,2-cyclohexanediaminetetraacetic acid (CyDTA), diethylenetriamine-N, N, N ′, N ′, N′-pentaacetic acid (DTPA), glycol ether diamine-N, N, N ′, N′-tetraacetic acid (GEDTA) and the like.

  In addition to these, an electrolyte or a cationic substance may be used to such an extent that a secondary obstacle does not occur. The electrolyte includes alkali metal ions such as lithium ion, sodium ion and potassium ion, and aluminum ion, barium ion, calcium ion, copper ion, iron ion, magnesium ion, manganese ion, nickel ion, tin ion, titanium ion and zinc ion. Etc.

Further, the ink used in the present invention may contain a surfactant or the like as a penetrating agent.
As the surfactant, any of nonionic, anionic, cationic, and amphoteric surfactants can be used. Nonionic surfactants include, for example, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan Examples include fatty acid esters, fatty acid alkylolamides, acetylene alcohol ethylene oxide adducts, polyethylene glycol polypropylene glycol block copolymers, glycerin ester polyoxyethylene ethers, sorbitol ester polyoxyethylene ethers, and the like.

  Examples of the anionic surfactant include alkylbenzene sulfonate, alkylphenyl sulfonate, alkyl naphthalene sulfonate, higher fatty acid salts, sulfate esters and sulfonates of higher fatty acid esters, and higher alkyl sulfosuccinates. May be.

  Examples of the cationic surfactant include tetraalkylammonium salts, alkylamine salts, benzalkonium salts, alkylpyridium salts, imidazolium salts, and the like. Examples thereof include dihydroxyethyl stearylamine, 2-heptadecenyl-hydroxyethylimidazoline. Lauryldimethylbenzylammonium chloride, cetylpyridinium chloride, stearamide methylpyridium chloride, and the like.

As the amphoteric surfactant, betaine, sulfobetaine, sulfate betaine, imidazoline and the like can be used. In addition, silicone surfactants such as polysiloxane polyoxyethylene adducts, fluorine surfactants such as oxyethylene perfluoroalkyl ether, biosurfactants such as splicrisporic acid, rhamnolipid, and lysolecithin can also be used.
These surfactants can be used alone or in admixture of two or more. The amount of the surfactant contained in the ink is desirably in the range of 0.001 to 10% by mass in total with respect to the total mass of the ink in consideration of surface tension and wettability.

  The ink used in the present invention preferably has a surface tension in the range of 20 to 60 mN / m.

In particular, the surface tension of the color ink containing a color material exhibiting a hue other than a black hue is preferably in the range of 20 to 45 mN / m, more preferably in the range of 20 to 40 mN / m, 25 A range of ˜35 mN / m is particularly preferable. When the surface tension of the color ink is in the range of 20 to 40 mN / m, the ink drying time is fast and it is easy to realize both image quality effects.
The surface tension of the color ink can be easily realized by adjusting the type and amount of the surfactant.

  Here, as the surface tension, a value measured in an environment of 23 ° C. and 55% RH using a Wilhelmy surface tension meter (manufactured by Kyowa Interface Science Co., Ltd.) was adopted.

-Treatment liquid-
The treatment liquid stored in the tank 54H used in the present invention thickens either one or both of the black ink and the color ink, or agglomerates the color material contained in either or both of the black ink and the color ink. Ingredients that contain water, a water-soluble organic solvent, and a surfactant described above as basic components and further agglomerate or thicken the ink (hereinafter referred to as ink aggregating agent) Can be selected according to the type of the color material contained in the.

As the ink aggregating agent, an electrolyte compound or a cationic compound is preferably used as the ink aggregating agent for an ink containing a colorant having an anionic group on the surface.
Examples of the electrolyte component of the electrolyte compound include alkali metal ions such as lithium ions, sodium ions, and potassium ions, and aluminum ions, barium ions, calcium ions, copper ions, iron ions, magnesium ions, manganese ions, nickel ions, tin ions, Polyvalent metal ions such as titanium ion, zinc ion, hydrochloric acid, odorous acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, thiocyanic acid, and acetic acid, oxalic acid, lactic acid, fumaric acid, fumaric acid, citric acid, Examples thereof include organic carboxylic acids such as salicylic acid and benzoic acid, and organic sulfonic acid salts.

  Specific examples of the ink aggregating agent containing the electrolyte listed above include lithium chloride, sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, potassium iodide, sodium sulfate, potassium nitrate, sodium acetate, and oxalic acid. Salts of alkali metals such as potassium, sodium citrate, potassium benzoate, and aluminum chloride, aluminum bromide, aluminum sulfate, aluminum nitrate, sodium aluminum sulfate, potassium aluminum sulfate, aluminum acetate, barium chloride, barium bromide, Barium iodide, barium oxide, barium nitrate, barium thioanate, calcium chloride, calcium bromide, calcium iodide, calcium nitrite, calcium nitrate, calcium dihydrogen phosphate, calcium thiocyanate, benzoic acid Calcium, calcium acetate, calcium salicylate, calcium tartrate, calcium lactate, calcium fumarate, calcium citrate, copper chloride, copper bromide, copper sulfate, copper nitrate, copper acetate, iron chloride, iron bromide, iron iodide, sulfuric acid Iron, iron nitrate, iron oxalate, iron lactate, iron fumarate, iron citrate, magnesium chloride, magnesium bromide, magnesium iodide, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium lactate, manganese chloride, manganese sulfate, manganese nitrate , Manganese dihydrogen phosphate, manganese acetate, manganese salicylate, manganese benzoate, manganese lactate, nickel chloride, nickel bromide, nickel sulfate, nickel nitrate, nickel acetate, tin sulfate, titanium chloride, zinc chloride, zinc bromide, sulfuric acid Zinc, zinc nitrate, zinc thiocyanate, zinc acetate, etc. Salts of polyvalent metals, and the like.

On the other hand, examples of the cationic compound include primary, secondary, tertiary and quaternary amines and salts thereof.
Specific examples of the ink aggregating agent made of the cationic compound include tetraalkylammonium salts, alkylamine salts, benzalkonium salts, alkylpyridium salts, imidazolium salts, polyamines, and the like. For example, isopropylamine, isobutyl Amine, t-butylamine, 2-ethylhexylamine, nonylamine, dipropylamine, diethylamine, trimethylamine, triethylamine, dimethylpropylamine, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, tetraethylenepentamine, diethanolamine, diethylethanolamine, triethylamine Ethanolamine, tetramethylammonium chloride, tetraethylammonium bromide, dihydroxyethylstearyl Min, 2-heptadecenyl - hydroxyethyl imidazoline, lauryl dimethyl benzyl ammonium chloride, cetyl pyridinium chloride, stearamide methyl pyridinium chloride, diallyldimethylammonium chloride polymers, diallylamine polymers include monoallylamine polymer and the like.

  Among the ink flocculants listed above, more preferable are aluminum sulfate, calcium chloride, calcium nitrate, calcium acetate, magnesium chloride, magnesium nitrate, magnesium sulfate, magnesium acetate, tin sulfate, zinc chloride, zinc nitrate. Zinc sulfate, zinc acetate, aluminum nitrate, monoallylamine polymer, diallylamine polymer, diallyldimethylammonium chloride polymer, and the like.

On the other hand, for an ink containing a colorant having a cationic group on the surface, it is preferable to use an anionic compound or the like as the ink aggregating agent.
Examples of the anionic compound include organic carboxylic acids or organic sulfonic acids, and salts thereof. Specific examples of the organic carboxylic acid include acetic acid, succinic acid, lactic acid, fumaric acid, citric acid, salicylic acid, benzoic acid, and the like, and an oligomer or polymer having a plurality of these basic structures may be used. Examples of the organic sulfonic acid include compounds such as benzenesulfonic acid and toluenesulfonic acid, and an oligomer or polymer having a plurality of these basic structures may be used.

  Only one type of ink flocculant contained in the ink processing liquid may be used, but two or more types may be used. Further, the content of the ink aggregating agent in the ink treatment liquid is preferably in the range of 0.1 to 15% by mass, and more preferably in the range of 0.5 to 10% by mass.

In addition, the treatment liquid used in the present invention may contain one or more of a water-soluble polymer, a water-soluble oligomer, a resin emulsion, and an inorganic oxide.
Examples of the resin emulsion include acrylic resins, vinyl acetate resins, styrene-butadiene resins, acrylic-styrene resins, butadiene resins, styrene resins, polyurethane resins, polyolefin resins, polyester resins, polyamide resins. , Melamine resin, urea resin, silicone resin, fluorine resin, polybutene resin, and various waxes. Examples of commercially available emulsions include Boncoat 4001 (acrylic resin emulsion, manufactured by Dainippon Ink & Chemicals, Inc.), Boncoat 5454 (styrene-acrylic resin emulsion, manufactured by Dainippon Ink & Chemicals, Inc.), J-74J. , J-734 (manufactured by Jonkrill Co., Ltd.) and the like, but are not limited thereto.

  The resin emulsion may be prepared by mechanically refining or dispersing a resin or wax in an aqueous medium, or directly polymerizing fine particles by emulsion polymerization, dispersion polymerization or suspension polymerization. In a preferred embodiment of the present invention, these resins are desirably polymers having both a hydrophilic part and a hydrophobic part. The particle shape may be spherical or any other shape. In the case of emulsion polymerization, either an emulsifier or soap-free may be used.

Examples of the inorganic oxide include, but are not limited to, high molecular weight silicic acid anhydride (SiO ₂ ) and alumina (Al ₂ O ₃ ).

  The volume average particle size of these resin emulsions or inorganic oxide colloids is preferably in the range of 10 nm to 2 μm, more preferably in the range of 50 to 500 nm. When the volume average particle diameter is larger than 2 μm, problems are likely to occur in the discharge stability of the processing liquid and the stability during standing. On the other hand, if it is smaller than 10 nm, problems such as leaving recovery of the nozzle are likely to occur.

  Moreover, the addition amount is preferably 0.1% by mass or more and 10% by mass or less in terms of solid content in the treatment liquid. If it is less than 0.1% by mass, there is a case where the density of the printed matter is not improved and the density is also lowered. When the amount exceeds 10% by mass, the ejection stability may be lowered or the image drying property may be deteriorated.

  The treatment liquid may be used as a colorless transparent liquid or may be used as, for example, a color ink containing a color material. In the latter case, it is preferable that the treatment liquid further contains the same color material as described above. The colorant contained in the treatment liquid is preferably a pigment as in the case of the ink.

  When the colorant is included in the treatment liquid, the colorant is preferably contained in the range of 1 to 15% by mass, and preferably in the range of 2 to 10% by mass with respect to the total mass of the treatment liquid. More preferred.

Moreover, it is preferable that the surface tension of the process liquid in this invention is the range of 20-40 mN / m. In such a range, the image drying time is fast and it is easy to realize both image quality effects.
The surface tension was measured under the environment of 23 ° C. and 55% RH using a Wilhelmy surface tension meter as described above.

Note that the permeation speeds of the ink and the treatment liquid used in the present invention with respect to the recording medium P are both preferably 5 seconds or less, and more preferably 3 seconds or less.
Further, the permeation speed varies depending on the relationship with the recording medium to be used. For example, when the permeation speed is 5 seconds or less with respect to plain paper, which is a general paper, it is used for ink and processing liquid. This can be easily realized by controlling the type and amount of the surfactant and the permeable solvent.

Further, it is preferable that the treatment liquid has a higher permeation speed with respect to the recording medium than the ink. If the permeation rate is lower for the treatment liquid than the ink, drying may be slow or image unevenness may occur. The permeation speed is determined by applying a load of 1.9 × 10 ⁴ N / m ² on another P paper (Fuji Xerox Office Supply) on the print pattern after a predetermined time has elapsed since the 100% coverage pattern was printed. And at this time, it can be calculated as the time during which ink is not transferred to the pressed P paper.

  In the ink jet recording apparatus 12 of the present embodiment having such an overall configuration, the recording medium P taken out from the paper feed tray 16 is transported and reaches the transport belt 28 as described above. Then, it is pressed against the conveyance belt 28 by the charging roll 36 and is held in a state of being attracted to the conveyance belt 28 by the applied voltage from the charging roll 36. In this state, an image is recorded on the recording medium P by discharging the treatment liquid and the ink droplets from the recording head 30 while the recording medium P passes through the discharge area SE by circulation of the conveying belt. The

  The recording medium P on which the image is recorded is peeled off from the transport belt 28 by the peeling plate 40, transported by the discharge roller pair 42, and discharged to the paper discharge tray 46.

  FIG. 4 shows a schematic block diagram of a control system of the inkjet recording apparatus 12. As shown in FIG. 4, the inkjet recording device 12 includes an image data acquisition unit 61 that acquires image data for image recording by the inkjet recording device 12, a control unit 60, a color / density conversion unit 62, an image processing unit 64, A recording data creation unit 66 and an image recording unit 68 are included. The image data acquisition unit 61, the color / density conversion unit 62, the image processing unit 64, and the recording data creation unit 66 are provided on the external device side such as a personal computer that outputs image data to the inkjet recording device 12. Also good.

  The control unit 60 is connected to the image data acquisition unit 61, the color / density conversion unit 62, the image processing unit 64, the recording data creation unit 66, and the image recording unit 68 so as to be able to send and receive signals, and comprehensively controls them. The image recording unit 68 includes components relating to image recording in the inkjet recording apparatus 12 described with reference to FIG.

  The image data acquisition unit 61 includes an external device such as a personal computer and a communication unit for acquiring image data via a wireless communication network or a wired communication network, and is recorded by the inkjet recording device 12 from the external device. To obtain image data. In the present embodiment, the image data acquisition unit 61 is described as acquiring image data from an external device. However, the image data is acquired by reading image data stored in a memory (not shown). It may be.

  The color / density conversion unit 62 performs, for example, color correction and density correction according to the characteristics of the recording medium P and ink, and converts the image data acquired by the image data acquisition unit 61 into CMYK data when the image data is RGB data. To do. The color correction processing is performed using a correction table generally called LUT (Look Up Table). The LUT may be stored in the color / density conversion unit 62 in advance.

  The image processing unit 64 performs so-called halftone processing. That is, data with a relatively high gradation such as 256 gradations is converted into image data with a number of gradations that can be recorded by the image recording unit 68. This process is performed for each color of YMCK.

  The number of gradations that can be recorded by the inkjet recording apparatus 12 is generally 2 to 8 gradations. For example, when converting YMCK color into four-gradation image data, four types of ink droplets are ejected for each YMCK color (for example, large droplets, medium droplets, small droplets, no droplets). )

  The recording data creating unit 66 includes a memory 67 for storing various data. Under the control of the control unit 60, the recording data creating unit 66 decodes the image data converted by the image processing unit 64 so that the image data has gradation levels that can be recorded by the image recording unit 68. After conversion to a possible data structure, the data is rearranged in the recording order (transfer order) to the image recording unit 68 and stored in the memory 67. This image data is created in consideration of the ejection timing and data arrangement mapped to the inkjet recording head 32 and the nozzle arrangement.

  In addition, since the inkjet recording apparatus 12 according to the present embodiment is configured to eject not only the four colors of YMCK ink but also the treatment liquid, the recording data creation unit 66 uses the treatment liquid dot data for the treatment liquid. (Details will be described later).

  Although details will be described later, the inkjet recording apparatus 12 according to the present embodiment not only ejects ink of a color according to image data according to each pixel, but also at the time of recording an image according to image data. The preliminary discharge is also performed. Therefore, the recording data creation unit 66 creates preliminary ejection dot data (details will be described later) under the control of the control unit 60.

  This preliminary ejection is ejection that is unrelated to ejection of ink droplets based on image data of an image to be recorded. In the present invention, color dots corresponding to color pixels (pixels showing hues other than black) of image data. The color ink droplet ejection is irrelevant to the color ink droplet ejection for recording the image.

  The image recording unit 68 uses the ink jet recording head 32H, the ink jet recording head 32Y, the ink jet recording head 32M, and the ink jet recording according to the image data created by the recording data creation unit 66, the preliminary ejection dot data, and the treatment liquid dot data. Ink and processing liquid are ejected from the nozzles of the head 32 </ b> C and the inkjet recording head 32 </ b> K under the control of the control unit 60. As a result, an image is recorded on the recording medium P.

  The control unit 60 includes a memory 60A for storing various data, and controls the color / density conversion unit 62, the image processing unit 64, the recording data creation unit 66, and the image recording unit 68.

  Next, as an operation of the present embodiment, processing executed by the control unit 60 will be described with reference to FIG.

  When power is supplied to each unit of the inkjet recording apparatus 12 by operating a power switch (not shown) by the user, the control unit 60 executes the processing routine shown in FIG. .

  In step 100, the image data acquisition unit 61 determines whether or not image data for an image to be recorded by the inkjet recording device 12 has been acquired. If the determination is negative, this routine is terminated. Proceed to

  In step 101, the color / density conversion unit 62 controls the color / density conversion unit 62 to perform color correction, density correction, and conversion processing to CMYK data for the image data acquired in step 100, and then the process is performed by the color / density conversion unit 62. The image processing unit 64 is controlled so as to perform halftone processing on the image data that has been processed. Furthermore, the image data converted by the image processing unit 64 is converted into image data having the number of gradations that can be recorded by the image recording unit 68, and the converted image data is mapped to the inkjet recording head 32 and the nozzle arrangement. The recording data creation unit 66 is controlled so as to create image data taking into account the ejection timing and data arrangement.

  In the next step 102, the recording data creation unit 66 is controlled so that the image data created by the recording data creation unit 66 in the above step 101 is stored in the memory 67 of the recording data creation unit 66.

  In the next step 103, it is determined whether or not there is a nozzle that requires preliminary ejection among the plurality of nozzles included in each of the inkjet recording head 32Y, the inkjet recording head 32M, and the inkjet recording head 32C.

  The determination in step 103 is performed by searching for nozzles that have been stored in a memory 60A provided in the control unit 60 and whose elapsed time from the date and time when the previous color ink was discharged is a predetermined time or more. Is possible.

In the memory 60A, a plurality of nozzles included in each of the inkjet recording head 32Y, the inkjet recording head 32M, and the inkjet recording head 32C are identified in advance, and corresponding to positional information indicating the arrangement position of each nozzle. The discharge date / time information indicating the date / time when the color ink was previously discharged may be stored.
The ejection date / time information may be updated every time an ink droplet is ejected from each nozzle.

  The determination in step 103 may be as follows. First, the control unit 60 searches for nozzles that have been stored in a memory 60A provided in the control unit 60 and that have elapsed from the discharge date and time when the previous color ink was discharged for a predetermined time or more. Next, if each of the pixels of the image data recorded in the memory 67 is not a pixel of the same hue as that of the ink of the hue ejected from the nozzle, the pixel that can be recorded by the searched nozzle is affirmed. You may do it.

  In this way, even if the nozzle has passed a predetermined time since the previous color ink was ejected, the ink droplet of the hue ejected by the nozzle during image formation based on the image data stored in the memory 67 In the case where the ink is discharged, it is possible to use a nozzle that is not a target for preliminary discharge, so that excessive consumption of ink droplets can be suppressed.

  In the next step 104, the position information indicating the nozzles that require preliminary ejection determined in step 103 is stored in the memory 60A as information indicating the nozzles that require preliminary ejection.

  In the next step 106, of the pixels of the image data stored in the memory 67, whether or not the region including the pixels that can be recorded by the nozzles that require preliminary ejection stored in the memory 60A in the step 104 is a black region. Is determined.

  This black area is an area in which one or a plurality of black dots corresponding to each pixel of the image data stored in the memory 67 is continuously recorded on the recording medium P. In addition, it is preferable from a viewpoint of image quality deterioration suppression that this black area | region is an area | region where a black dot continues at least 3 dots or more.

  This black area is specified by searching for pixels in the pixel of the image data stored in the memory 67 that are black pixels that can be recorded by the nozzles requiring preliminary ejection stored in the memory 60A in step 104 above. can do.

  In order to define this black region as a region in which a plurality of black dots or more are continuous, the pixels that can be recorded by the nozzles that require preliminary ejection stored in the memory 60A in step 104 are black pixels. It can be specified by searching for a pixel in which a plurality of continuous pixels are black pixels.

If the result in Step 106 is negative, the process proceeds to Step 116, where the image data stored in the memory 67 of the recording data creating unit 66 is transferred to the image recording unit 68, and then proceeds to Step 114 described later.
In the image recording unit 68, when the image data stored in the memory 67 of the recording data creation unit 66 is transferred from the control unit 60, the inkjet recording head 32Y, the inkjet recording head 32M, and the inkjet recording are based on the image data. By ejecting ink droplets from the nozzles of the head 32C and the inkjet recording head 32K according to the positions of the nozzles, dots corresponding to the pixels of the image data are recorded.

On the other hand, if the result is affirmative in step 106, the process proceeds to step 108, and among the pixels of the image data stored in the memory 67, the pixel at the position that can be recorded by the nozzle that requires the preliminary ejection stored in the memory 60 </ b> A in step 104. As the position information indicating the position of the black pixel so that the processing liquid is ejected to the same area as the area where the black dot is recorded according to the black pixel of the image data or the same area and surrounding dots. Corresponding processing liquid dot data indicating the discharge amount of the processing liquid is created.
In the processing of step 110, the amount of the processing liquid is preferably 5 to 50% of the black dots.

In the next step 110, among the pixels of the image data stored in the memory 67, the black pixels of the image data are recorded as the pixels at positions that can be recorded by the nozzles that require the preliminary ejection stored in the memory 60A in the above step 104. Accordingly, the position of the black pixel is such that the color ink of the hue corresponding to the nozzle is ejected from the nozzle requiring the preliminary ejection stored in the memory 60A in step 104 to the same area as the area where the black dot is recorded. The preliminary discharge dot data indicating the discharge amount of the color ink corresponding to the color of the nozzle that requires the preliminary discharge is created in association with the position information indicating the above.
In the processing of step 110, the amount of the processing liquid is preferably 5 to 50% of the total amount of black ink and color ink.

  In the process of step 110, the discharge amount of the color ink to be preliminarily discharged is discharged to the same region so that at least the dots below the black region recorded in the same region are recorded. The drop amount is set to be equal to or less than the drop amount of black ink.

  In addition, when the positions of the nozzles capable of ejecting dots in the same region on the recording medium P are the same in at least two of the inkjet recording head 32Y, the inkjet recording head 32M, and the inkjet recording head 32C, the same Since the color ink ejected to the black area becomes one color (that is, any one of yellow, magenta, and cyan), the total amount of color ink ejected by the preliminary ejection to the same black area is the black area. It is preferable that the amount be less than or equal to the amount of black ink discharged.

  Also, according to the total amount of color ink (total discharge amount) discharged by preliminary discharge to the same black area, this total amount is 25% per color (if there are two colors, the discharge amount of two colors of ink) If the total amount of the black ink and the color ink exceeds 50%, the amount of the black ink discharged to the black region may be reduced so that the total discharge amount of the black ink and the color ink does not exceed 150%.

Each of the 50%, 25%, and 150% is 100% of the total ink discharge amount when a large amount of ink (for example, black ink) is discharged to a predetermined area, for example, all the area on the recording medium. It is the value.
In this way, it is possible to obtain the effects of suppressing the decrease in the drying speed, the curling of the paper and the occurrence of cockle, and the reduction in the amount of black ink used.

  In the next step 112, the image data stored in the memory 67 of the recording data creation unit 66, the treatment liquid dot data created in step 108, and the preliminary ejection dot data created in step 110 are image-recorded. The data is transferred to the unit 68.

  In the image recording unit 68, the image data stored in the memory 67 of the recording data creation unit 66 from the control unit 60, the treatment liquid dot data created in step 108, and the preliminary ejection dot data created in step 110. Are transferred from the nozzles of the ink jet recording head 32Y, the ink jet recording head 32M, the ink jet recording head 32C, and the ink jet recording head 32K based on these data in accordance with the position of each nozzle. By discharging, dots corresponding to each pixel of the image data are recorded, and processing liquid and color ink for preliminary discharge are discharged according to the position of each nozzle.

  Therefore, the recording medium P is ejected with ink droplets having a hue and a droplet amount corresponding to each pixel of the image data stored in the memory 67, and a black dot is formed based on the image data. In the case where a nozzle that requires preliminary ejection corresponds to the black area, the inkjet recording head 32Y, the inkjet recording head 32M, and the inkjet recording head 32C are discharged to the black area after the processing liquid is ejected by the inkjet recording head 32H. After the color ink droplets are ejected from the nozzles that require preliminary ejection among these nozzles, the black ink droplets of the amount corresponding to the black pixels of the image data are finally ejected by the inkjet recording head 32K.

  In the ink jet recording apparatus 12 of the present invention, the ink jet recording head 32H, the ink jet recording head 32Y, the ink jet recording head 32M, the ink jet recording head 32C, and the ink jet recording head 32K are arranged in order along the conveyance direction of the recording medium P. However, they need not be arranged in this order at least. Preferably, the ink jet recording head 32H, the ink jet recording head 32Y, and the ink jet are arranged along the transport direction of the recording medium P so that black ink droplets are ejected after the treatment liquid is ejected to the same region on the recording medium P. The recording head 32M, the ink jet recording head 32C, and the ink jet recording head 32K may be arranged. However, after the treatment liquid is discharged to the same area on the recording medium P, the ink droplets are discharged in the order of color ink and black ink. It is particularly preferable from the viewpoint of preventing color change and preventing the drying rate from decreasing.

  In the next step 114, for the nozzles that ejected ink droplets based on the image data in the image recording process of step 112 or step 116, ejection corresponding to the position information of each nozzle stored in the memory 60A. After updating the date and time information to date and time information indicating the date and time when ink droplets were ejected in step 116, this routine is terminated.

  As described above, according to the liquid droplet ejection apparatus of the present invention, when color ink droplets are preliminarily ejected from nozzles that require preliminary ejection, the black dots corresponding to the black pixels of the image data are recorded. Since the processing liquid, the color liquid droplet as a preliminary discharge, and the black liquid droplet for recording the black dot corresponding to the black pixel can be discharged so as to overlap with the black region, Due to the effect of the processing liquid, at least one of the black droplets and the color droplets can be prevented from protruding outside the region to be originally formed, and image quality deterioration can be suppressed.

  Also, since the color ink droplets as preliminary ejection are ejected to the black area where the black dots corresponding to the black pixels of the image data are recorded, the drainage receiving portion for performing preliminary ejection as in the prior art Therefore, it is possible to efficiently perform image recording processing while suppressing an increase in the size of the droplet discharge device.

  Therefore, it is possible to provide a droplet discharge device that can suppress an increase in size of the droplet discharge device and can suppress deterioration in image quality.

  In the present embodiment, the case where a long recording head array having an effective recording area having a length equal to or larger than the width of the paper is described. However, the effective recording area has a length less than the width of the recording medium P. The present invention can also be applied to an ink jet printer that records an image while scanning a recording head array having a thickness in a direction orthogonal to the paper conveyance direction.

In the above description, the case where the color ink as the preliminary discharge, the processing liquid, and the black ink corresponding to the black pixel corresponding to the black area of the image data is discharged to the black area is described. Alternatively, the same amount of each of the three color inks of yellow, magenta, and cyan may be ejected so that the black ink is not ejected.
In this way, since black can be expressed by three colors of yellow, magenta, and cyan, consumption of black ink for forming a black region can be suppressed.

  In this case, in the process of step 112, the image data, the processing liquid dot data, and the preliminary discharge dot data are transferred, and the nozzle that requires the preliminary discharge stored in the memory 60A in step 104 is used. At the pixels where printing is possible, data indicating that black ink is not ejected and data indicating that the same amount of ink of three colors of cyan, magenta, and yellow are ejected are transferred to the image recording unit 68. That's fine.

Further, after ejecting the same amount of the three color inks of yellow, magenta, and cyan, black ink corresponding to the black pixel corresponding to the black region may be further ejected. In this way, image quality deterioration can be suppressed.
In this case, in the process of step 112, the image data, the processing liquid dot data, and the preliminary discharge dot data are transferred, and the nozzle that requires the preliminary discharge stored in the memory 60A in step 104 is used. In the pixels at the recordable position, data indicating that the same amount of ink of three colors of cyan, magenta, and yellow is ejected and data indicating that the black ink droplets corresponding to the pixels are ejected are stored in the image recording unit 68. Should be transferred to.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited only to a following example.

<Adjustment of ink and treatment liquid>
In accordance with the composition of the ink and the treatment liquid shown below, a drop amount of the pigment dispersion is added with a drop of a water-soluble organic solvent, a surfactant, ion-exchanged water, etc. Were mixed and stirred, and filtered through a 1 μm aperture filter to obtain the desired ink and treatment liquid.

-Black ink adjustment-
Mogul L (manufactured by Cabot): 4 parts by mass, styrene-acrylic acid-n-butyl-sodium acrylate copolymer: 0.6 parts by mass, diethylene glycol: 15 parts by mass, diglycerin ethylene oxide adduct: 5 parts by mass Polyoxyethylene-2-ethylhexyl ether: 0.75 parts by mass, ion-exchanged water: remainder, surface tension: 33 mN / m

-Preparation of C color ink (dye)-
・ C. I. Acid Blue 9 (dye) 3.5% by mass
・ Diethylene glycol 20% by mass
・ 1,5-pentanediol 5% by mass
・ Diethylene glycol monobutyl ether 2.5% by mass
・ Acetylene glycol ethylene oxide adduct 1% by mass
・ Sodium hydroxide 0.4% by mass
・ 3-pyrrolidone-5-carboxylic acid 3% by mass
-Ion exchange water remainder-Surface tension: 32MN / m.

-Preparation of C color ink (pigment)-
C. I. Pigment Blue 15: 3 (self-dispersing) 4% by mass
・ Styrene-acrylic acid copolymer (acid value 100 / neutralization degree 95%) 0.6% by mass
・ Diethylene glycol 20% by mass
・ Propylene glycol 5% by mass
・ Acetylene glycol ethylene oxide adduct 1% by mass
-Ion exchange water remainder-Surface tension: 32 mN / m.

-Preparation of C color ink (SD)-
C. I. Pigment Blue 15: 3 (self-dispersing) 4% by mass
・ Styrene-acrylic acid copolymer (acid value 100 / neutralization degree 95%) 0.6% by mass
・ Diethylene glycol 20% by mass
・ Propylene glycol 5% by mass
・ Acetylene glycol ethylene oxide adduct 0.05% by mass
-Ion exchange water remainder-Surface tension: 49 mN / m.

-Preparation of M color ink-
・ C. I. Pigment Red 122 (self-dispersing) 4% by mass
・ Styrene-acrylic acid copolymer (acid value 100 / neutralization degree 95%) 0.6% by mass
・ Diethylene glycol 20% by mass
・ Triethylene glycol 5% by mass
・ Acetylene glycol ethylene oxide adduct 1% by mass
・ Ion-exchanged water balance Surface tension: 32 mN / m

-Preparation of Y color ink-
・ C. I. Pigment Yellow 128 (self-dispersing) 4% by mass
・ Styrene-acrylic acid copolymer (acid value 100 / neutralization degree 95%) 0.6% by mass
・ Diethylene glycol 20% by mass
・ 2-Pyrrolidone 5% by mass
・ Acetylene glycol ethylene oxide adduct 1% by mass
・ Ion-exchanged water balance ・ Surface tension: 32 mN / m

―Preparation of treatment solution―
-Diethylene glycol: 30 parts by mass-Succinic acid: 7 parts by mass-Sodium hydroxide: 3 parts by mass-Acetylene glycol ethylene oxide adduct: 1 part by mass-Ion-exchanged water: Remaining-Surface tension: 33 mN / m

  Here, as the surface tension, a value measured in an environment of 23 ° C. and 55% RH using a Wilhelmy surface tension meter (manufactured by Kyowa Interface Science Co., Ltd.) was adopted.

-Recording media-
As a recording medium used for the printing test, A4 paper (210 × 297 mm, P paper, manufactured by Fuji Xerox Office Supply) was used.
The penetration speed of the black ink to this paper is 1 second or less, the penetration speed of cyan ink (both pigment and dye) is 1 second or less, and the penetration speed of magenta ink is 1 second or less, The penetration speed of the yellow ink is 1 second or less, the penetration speed of the cyan ink is 5 seconds, and the penetration speed of the treatment liquid is 1 second or less.

<Print test>
In the printing test, a piezo ink jet type prototype recording apparatus (manufactured by Fuji Xerox Co., Ltd.) using the ink and the treatment liquid and equipped with a recording head of 1200 dpi and 360 nozzles was used.
In addition, this recording apparatus modifies the control unit in the prototype so that the processing routine shown in FIG. 5 is executed, and color ink and black ink are ejected after the processing liquid. An ink jet recording head 32 (see FIG. 1) is arranged.

In the print test, the scan speed of the recording head, the time from discharge of the treatment liquid to the discharge of ink, and the printing environment are all performed under the following conditions, and the voltage applied to the piezoelectric element of the inkjet recording head The waveform was also constant (same applied waveform condition).
・ Scanning speed of inkjet recording head: 57.15 cm / sec
・ Time from discharge of treatment liquid to discharge of color ink: 18 msec
・ Printing environment: Temperature: 23 ± 0.5 ℃, Humidity: 55 ± 5% RH

  Under the conditions described above, the amount of ink droplets discharged from the ink jet recording head and the droplet amount of the treatment liquid (liquid amount per droplet) were prepared as follows.

Example 1: Pigment C ink 4 pl and black ink 10 pl are ejected in order on the treatment liquid 4 pl.
Comparative Example 1: Black ink 10 pl was discharged after the pigment C ink 4 pl was discharged without discharging the treatment liquid.
Example 2: 10 pl of pigment C ink and 8 pl of black ink are ejected in sequence on the treatment liquid 4 pl.
Example 3: Dye C ink 4 pl and black ink 10 pl are sequentially ejected onto the treatment liquid 4 pl.
Example 4: SDC ink 4 pl and black ink 10 pl are sequentially ejected onto the treatment liquid 4 pl.
Example 5: Y ink 2pl, M ink 2pl, pigment C ink 2pl, and black ink 6pl are sequentially ejected onto the treatment liquid 4pl.
Example 6: Y ink 2pl, M ink 2pl, pigment C ink 2pl, and black ink 12pl are ejected onto the treatment liquid 4pl.

For each of Examples 1 to 6 and Comparative Example 1, each of image quality, back-through, and curl cockle of the entire paper was evaluated.
The curl refers to the lifting of the edge of the paper as it dries after printing, and the curl refers to the unevenness that occurs at the print location and occurs immediately after printing.
The evaluation method and evaluation criteria are as follows.

-image quality-
The image quality was visually evaluated for print samples. The evaluation criteria are as follows.
○: No change in color of black ink.
Δ: Small change in color of black ink.
X: Clearly colors other than black are mixed.

-Back-through-
The strike-through was visually evaluated on the printed sample. The evaluation criteria are as follows.
○: There is no strikethrough.
(Triangle | delta): A strike-through is smaller than a dot of a table | surface, and it understands with an eye.
X: The strike-through occurs at the same size as the front dot.

-Curled cockle-
The curl cockle left the print sample, and visually observed the deformation of the paper immediately after printing and 24 hours. The evaluation criteria are as follows.
○: Almost no paper deformation.
Δ: Slight paper deformation is observed.
×: Paper deformation is conspicuous.

  The evaluation results are shown in Table 1.

As can be seen from Table 1, in Examples 1 to 6 using the treatment liquid, image quality deterioration could be suppressed as compared with Comparative Example 1 in which the treatment liquid was not used.
Further, in Examples 1 to 6, when the amount of color ink droplets is smaller than the amount of black ink droplets as in Example 1, or as shown in Example 5, the color is smaller than the amount of black ink droplets. When the total amount of ink droplets was small, good results were obtained for both image quality and show-through.

Further, as in Example 2, when the total amount of color ink droplets is larger than the amount of black ink droplets and the treatment liquid is applied, the show-through is good and the image quality is slightly smaller than that of Example 1. Although a change in color occurred, a better result than that of Comparative Example 1 was obtained.
Further, as in Example 3, when the color material of the color ink is a dye and the amount of drops of the color ink is smaller than the amount of drops of the black ink, good results can be obtained for the image quality, and the showthrough ,It was good.
Similarly, when the surface tension of the color ink is 49 mN / m and the drop amount of the color ink is smaller than the drop amount of the black ink as in the fourth embodiment, the image quality is slightly lower than that in the first embodiment. Although the color change occurred, both the image quality and the show-through were good as compared with Comparative Example 1.
Also, in Example 6, both image quality and show-through were good as compared with Comparative Example 1.

1 is a schematic configuration diagram of an ink jet recording apparatus according to the present invention. (A) is a waveform showing the voltage applied when ejecting a large droplet from a nozzle, (B) is a schematic diagram showing the periphery of the nozzle of the ink jet recording head of the ink jet recording apparatus according to the present invention, (C ) Is a waveform showing a voltage applied when a small droplet is ejected from the nozzle, and (D) is a schematic diagram showing the periphery of the nozzle of the ink jet recording head of the ink jet recording apparatus according to the present invention. FIG. 2 is a schematic configuration diagram illustrating a conveyance belt and its vicinity of the ink jet recording apparatus according to the present invention. It is a control block diagram of the ink jet recording apparatus according to the present invention. It is a flowchart which shows the process performed by the control part of the inkjet recording device of this invention.

Explanation of symbols

12 Inkjet recording device 32H Inkjet recording heads 32Y, 32M, 32C, 32K Inkjet recording head 60 Control unit 61 Image data acquisition unit 61 Image data acquisition unit

Claims (8)

A black liquid droplet discharge head that records black dots corresponding to black pixels of image data by discharging black liquid droplets containing at least a black color material from the nozzle;
A color droplet discharge head that records color dots corresponding to color pixels of a hue other than black in the image data by discharging color droplets containing a color material of a hue other than black from the nozzle; and
A processing liquid that discharges a processing liquid that thickens one or both of the black liquid droplets and the color liquid droplets or agglomerates a color material contained in one or both of the black liquid droplets and the color liquid droplets A discharge head;
Acquisition means for acquiring image data;
A discriminating means for discriminating whether or not a preliminary ejection different from the color liquid droplet ejection based on the image data obtained by the obtaining means is required for the nozzles of the color liquid droplet ejection head;
When the determination unit determines that preliminary discharge is necessary, the processing liquid is discharged to a black region where black dots corresponding to black pixels of the image data acquired by the acquisition unit are to be recorded. Controlling the treatment liquid ejection head as described above, and controlling the color liquid droplet ejection head so that the color liquid droplets are ejected from the nozzles determined to require the preliminary ejection in the black region, Control means for controlling the black droplet discharge head so that black droplets corresponding to the black pixels are discharged into a black region;
A droplet discharge device comprising:   The control unit searches for a pixel in which pixels that can be recorded by the nozzle determined to require preliminary ejection by the determining unit among the pixels of the image data acquired by the acquiring unit are black pixels. The droplet discharge apparatus according to claim 1, wherein the black region is a region in which black dots corresponding to black pixels searched by the search unit are recorded.   3. The droplet discharge device according to claim 1, wherein the black region is a region in which a plurality of black dots corresponding to black pixels of image data are continuously recorded.   4. The droplet discharge device according to claim 1, wherein an amount of the color droplets discharged to the black region is smaller than an amount of the black droplets discharged to the black region.   5. The droplet discharge device according to claim 1, wherein a surface tension of the color droplet is 40 mN / m or less. A black liquid droplet discharge head that records black dots corresponding to black pixels of image data by discharging black liquid droplets containing at least a black color material from the nozzle;
A cyan liquid discharge head that records cyan dots according to cyan pixels of image data by discharging cyan color liquid droplets from the nozzle;
A cyan liquid discharge head that records magenta color dots corresponding to magenta color pixels of image data by discharging magenta color liquid droplets from the nozzle;
A yellow liquid discharge head that records yellow dots according to yellow pixels of image data by discharging yellow color liquid droplets from nozzles;
Each of the cyan color droplet, the magenta color droplet, and the yellow color droplet is thickened, or the cyan color droplet, the magenta color droplet, and the yellow A treatment liquid discharge head for discharging a treatment liquid for aggregating the color material contained in the color droplets of the color;
Acquisition means for acquiring image data;
Color droplet discharge based on image data acquired by the acquisition means for the nozzles included in the cyan liquid discharge head, the nozzles included in the magenta liquid discharge head, and the nozzles included in the yellow liquid discharge head A discriminating means for discriminating whether or not different preliminary ejection is necessary;
Among the pixels of the image data acquired by the acquisition unit when the determination unit determines that the preliminary discharge is necessary, a pixel that can be recorded by the nozzle that needs the preliminary discharge is a black pixel. The processing liquid ejection head is controlled so that the processing liquid is ejected to a black area where black dots corresponding to the searched black pixel are recorded, and the cyan area is scanned with the cyan color. Control means for controlling the cyan liquid discharge head, the magenta liquid discharge head, and the yellow liquid discharge head such that a color liquid droplet, the magenta color liquid droplet, and the yellow color liquid droplet are discharged. When,
A droplet discharge device comprising:   The liquid droplet ejection apparatus according to claim 6, wherein the control unit controls the black liquid droplet ejection head so that black dots corresponding to the searched black pixels are recorded in the black region.   The liquid droplet ejection apparatus according to claim 1, wherein the color material is a pigment or a dye.

Images