JP4518098B2 - Color mixing determination method and image recording method and apparatus - Google Patents

Description

  The present invention relates to a color mixing determination method and an image recording method and apparatus, and in particular, avoids color mixing of ink on the surface of a recording medium when an image is recorded by ejecting ink from a large number of nozzles toward the recording medium. Regarding technology.

  2. Description of the Related Art Conventionally, an image recording apparatus has an inkjet head (ink ejection head) in which a large number of nozzles are arranged, and recording is performed by ejecting ink from the nozzles while relatively moving the inkjet head and the recording medium. 2. Related Art An ink jet recording apparatus (ink jet printer) that records an image on a medium is known.

  Conventionally, various methods are known as ink ejection methods in such an ink jet recording apparatus. For example, the diaphragm constituting a part of the pressure chamber (ink chamber) is deformed by deformation of the piezoelectric element (piezoelectric ceramic) to change the volume of the pressure chamber, and when the volume of the pressure chamber is increased, Ink is introduced into the pressure chamber, and when the volume of the pressure chamber is reduced, the ink is ejected as droplets from the nozzle, or the ink is heated to generate bubbles and the expansion energy when the bubbles grow. A thermal ink jet method for discharging is known.

  In an image recording apparatus having an ink discharge head such as an ink jet recording apparatus, ink is supplied from an ink tank for storing ink to an ink discharge head via an ink supply path, and ink is discharged by the above various discharge methods. However, when recording a color image using a plurality of different color inks, if the previously recorded ink is not yet fixed and cured, recording with the different color inks may cause color mixing. The image quality is degraded.

  In view of this, various methods have been proposed in the past for preventing color mixing that occurs when inks of different colors are overlaid and improving image quality.

  For example, during one rotation of the rotating body holding the recording medium, each color ink dot sprayed from the recording head for each color is thinned out at least one dot away in the same sub-scanning direction as the rotation direction on the recording medium. It is known that recording is performed so that high-quality recording is performed while preventing mixing and flow of adjacent ink dots (see, for example, Patent Document 1).

  Further, for example, the inkjet recording apparatus has a means for estimating the dry state of the recorded ink, and the previous recording can be performed by changing the conveyance speed of the recording medium or changing the interval between the recording heads according to the estimation result. In order to improve the image quality, the recording interval between one recording and the next recording is changed to prevent the recording disturbance in the portion where different inks are superimposed while maintaining the throughput of the recording apparatus. (For example, see Patent Document 2).

Further, for example, in the color ink jet recording method, for the same print region, the time for printing by at least one of the plurality of heads is sufficiently longer than the print delay time of the adjacent heads than the time of printing by the other heads. It is known to obtain a color print with no blur between colors after printing (see, for example, Patent Document 3).
JP 2000-71481 A Japanese Patent Laid-Open No. 03-247450 JP 04-173250 A

  However, for example, in the one described in Patent Document 1, when the rotating body holding the recording medium rotates once, recording is performed with one dot thinned out, and multiple rotations are required to record the entire image. There is a problem that productivity is low.

  Moreover, although the thing of the said patent document 2 has a means to estimate drying, and a means to adjust a dot recording interval, it adjusts the space | interval which records the next dot according to a dry state. However, there is no means for fixing or curing the ink that has landed on the recording medium, and it is simply left to natural drying, and there is a problem that color mixing cannot be reliably prevented.

  Further, the one described in Patent Document 3 has a problem similar to that of Patent Document 2 because it merely takes a time longer than the adjacent dot printing delay and does not have any means for adjusting fixing and curing.

  The present invention has been made in view of such circumstances, and it is possible to determine the color mixture of ink ejected from an ink ejection device onto a recording medium and landed on the surface of the recording medium, thereby enabling image recording while avoiding the color mixture. It is an object of the present invention to provide a color mixing determination method and an image recording method and apparatus.

In order to achieve the above object, according to the first aspect of the present invention, droplets are ejected from a first print head having a nozzle array for ejecting ink of the first color toward a recording medium, and the first By moving the print head and the recording medium relative to each other, a rectangular first color area in which a plurality of dot rows of ink dots of the first color are aligned in the relative movement direction on the recording medium is integrated. A printing process and a second print head having a nozzle row that ejects ink of a second color different from the first color are applied to a range where the first color area on the recording medium partially overlaps and is adjacent. By performing droplets and relatively moving the second print head and the recording medium, a plurality of dot rows of ink dots of the second color are arranged in the relative movement direction, and the ink of the second color Do by dot A step of printing a rectangular second color area in which a part of the first color area overlaps with the first color area, and the first color area and the second color area partially overlap each other. And forming an overlapping portion of the first color region and the second color region in the color mixture determination patch along a direction in which the first color region and the second color region are adjacent to each other. The step of measuring the density of each color of the first color and the second color with a densitometer and obtaining a density profile of each color in the adjacent direction by the density measurement with respect to the patch for color mixture determination It is performed at a plurality of positions in a direction orthogonal to the adjacent direction, and a plurality of sets of two color density profiles corresponding to the plurality of positions are obtained, and a predetermined threshold value is obtained from each set of two color density profiles. Dark It obtains distances between points, and calculate at least one of the mean and standard deviation of the distance, determining the color mixture state of two colors in the overlapping portion based on at least one of the mean and standard deviation the calculated There is provided a color mixing determination method characterized by the above.

  Thereby, the color mixture of the ink ejected on the recording medium can be easily determined automatically.

Further, the invention according to claim 2, starts ejecting the mixing evaluation method according to claim 1, wherein said overlapping said first color timing to start ejecting ink dots of the second color ink dot in the portion Timing Discharge time difference, relative conveyance speed of the recording medium with respect to the first and second print heads, fixing energy for fixing the ink dots on the recording medium to the recording medium, and curing the ink on the recording medium A plurality of color mixture determination patches are formed on the same recording medium by changing at least one of the curing energies to be used as a parameter, and each color mixture determination on the color mixture determination print having the plurality of color mixture determination patches The patch is configured to determine a color mixture state of the overlapping portion based on the density profile. To provide a color determination method.

  Note that the ejection time difference between the two color dots can be changed by changing the conveyance speed of the recording medium or changing the distance between the heads provided for each color.

Similarly, in order to achieve the above object, according to a third aspect of the present invention, in the color mixing determination method according to the second aspect, the average value of the distance, the standard deviation, the discharge time difference, and the recording on the recording medium. ones recording mode indicating whether text or images or both, of the color mixing state by calculating the evaluation value by weighting factors for calculating the evaluation value used in the determination of the color mixing according to the respective The present invention provides a color mixing determination method characterized by performing the determination .

  Accordingly, it is possible to maintain high image quality by changing the weighting when determining the color mixture according to the recording mode depending on the type of recording data.

Further, in order to attain the aforementioned object, the invention according to claim 4, based on the color mixing evaluation result by claim 2 or 3 mixing evaluation method described, before Ki吐 out time difference, the relative transport speed, before Kijo wear energy, and sets the control parameters for controlling at least one one of the previous Kikata of energy, an image recording method and performs image recording on the recording medium based on the set I will provide a.

The invention according to claim 5 is the image recording method according to claim 4 , wherein the type of ink , the type of the recording medium, and what is recorded on the recording medium is text or image According to another aspect of the present invention, there is provided an image recording method in which the control parameter is set in accordance with a recording mode indicating either or both.

  Thus, high-quality image recording that avoids color mixture using the color mixture determination result is possible.

Similarly, in order to achieve the above object, the invention according to claim 6 performs droplet ejection from the first print head having a nozzle row for ejecting the first color ink toward the recording medium, By moving the first print head and the recording medium relative to each other, a rectangular first shape in which a plurality of dot rows of ink dots of the first color are arranged side by side in the relative movement direction on the recording medium. While performing control to print one color area, the first color area on the recording medium partially overlaps from a second print head having a nozzle row that ejects ink of a second color different from the first color. In addition, when droplets are ejected in adjacent ranges and the second print head and the recording medium are relatively moved, a plurality of dot rows of ink dots of the second color are arranged in the relative movement direction, and The second color The first color area and the second color area are partly obtained by performing control to print a rectangular second color area in which a part of a dot row of ink dots overlaps and is integrated with the first color area. and color mixing evaluation print output means for forming a manner overlapping color mixing evaluation patches, and wherein the first color regions along the second color regions and the direction in which the adjacent, said in the color mixing evaluation patches first color regions Density measuring means for measuring a density of each of the first color and the second color at a plurality of locations including an overlapping portion of the second color region, and obtaining a density profile of each color in the adjacent direction by the density measurement; to obtain the perform the concentration measurement at a plurality of positions in the direction orthogonal to the direction in which adjacent the terms mixing evaluation patch, a plurality of sets of density profiles of two colors corresponding to the plurality of locations The distance between the density points, which are the predetermined threshold values, is obtained from the density profiles for the two colors of each set, and at least one of the average value and the standard deviation of the distance is calculated, and the calculated average value and standard deviation are calculated. There is provided a color mixing determining device comprising: a color mixing determining means for determining a color mixing state of two colors in the overlapping portion based on at least one of them .

According to a seventh aspect of the present invention, in the mixed color determination apparatus according to the sixth aspect, the mixed color determination print output means starts the ejection of the first color ink dots in the overlapping portion and the second color ink. Discharge time difference from the timing to start ejecting dots , relative conveyance speed of the recording medium with respect to the first and second print heads, fixing energy for fixing ink dots on the recording medium to the recording medium, and the recording A color mixture determination print having a plurality of color mixture determination patches formed on the same recording medium by changing at least one of the curing energies for curing ink on the medium as a parameter, and having the plurality of color mixture determination patches. Is provided. The present invention provides a color mixing judgment device characterized in that

According to an eighth aspect of the present invention, in the color mixing determination device according to the seventh aspect, the color mixing determination means records the average value of the distance, the standard deviation, the discharge time difference, and the text recorded on the recording medium. The color mixing state is determined by calculating the evaluation value by weighting the element for calculating the evaluation value used for the determination of the color mixture according to each of the recording modes indicating the image, the image, or both. There is provided a color mixing judgment device characterized by the above.

Similarly, in order to achieve the object, the invention according to claim 9 includes a first print head having a nozzle array for discharging the first color ink, and a second color different from the first color. A second print head having a nozzle array for ejecting ink, and means for moving the recording medium relative to the first and second print heads, and ejects dots onto the recording medium. An image recording apparatus that performs image recording by using the color mixing determination apparatus according to any one of claims 6 to 8, and controls a difference in dot ejection time between the first and second print heads. curing the discharge time difference controlling means, and fixing means for fixing the ejected dots on said recording medium, and a fixing control means for controlling the fixing energy of the fixing means, the ejected dot on said recording medium Curing means, A curing control means for controlling the curing energy of the serial curing means, on the basis of the color mixing evaluation result by the mixing evaluation device, the discharge time difference control unit, control for controlling at least one of the fixing control unit and the hardening control means comprises a parameter setting means for setting the parameters, and to provide an image recording apparatus which is characterized in that the parameter set control parameter images recorded by the at setting means.

  As a result, it is possible to automatically set the optimum control parameters for avoiding color mixing.

Similarly, in order to achieve the above object, the invention according to claim 10 includes a first print head having a nozzle row for discharging the first color ink, and a second color different from the first color. a second print head having a nozzle array to discharge ink, and means for relatively moving said recording medium relative to the front Symbol first and second print heads, the recording medium from the first print head The droplets are ejected toward the surface and the first print head and the recording medium are relatively moved, whereby a plurality of dot rows of ink dots of the first color are arranged in the relative movement direction on the recording medium. While performing control to print the integrated rectangular first color area, droplets are ejected from the second print head to a range that partially overlaps the first color area on the recording medium. And the second print head and the front By moving the print medium relative to the recording medium, a plurality of dot rows of the second color ink dots are arranged in the relative movement direction, and a part of the dot rows of the second color ink dots is the first color region. The color mixture determination for forming a color mixture determination patch in which the first color area and the second color area partially overlap each other is performed by performing control to print the rectangular second color area that overlaps and is integrated Controls the ejection time difference between the print output means and the timing at which the first print head starts ejecting dots when recording data is recorded on the recording medium and the timing at which the second print head begins to eject dots. A discharge time difference control unit; a fixing unit that fixes dots ejected onto the recording medium; and a fixing control unit that controls the fixing energy of the fixing unit. Based on the curing unit that cures the dots deposited on the recording medium, the curing control unit that controls the curing energy of the curing unit, and the color mixture determination patch, the determination result of the color mixture of two colors is input. And at least one of the discharge time difference control unit, the fixing control unit, and the curing control unit based on the mixed color determination result input unit and the determination result of the mixed color input to the mixed color determination result input unit. There is provided an image recording apparatus comprising: parameter setting means for setting a control parameter, wherein image recording is performed according to the control parameter set by the parameter setting means.

  Thereby, for example, the control parameter is set by inputting the color mixture determination result determined by visual observation or the like.

Furthermore, the invention according to claim 11 is the image recording apparatus according to claim 9 or 10 , further comprising an ink type detecting means for detecting the type of ink, and a recording medium for detecting the type of the recording medium. A recording mode detecting unit for detecting a recording mode indicating whether the data to be recorded is text, an image, or both, and the control is performed according to the ink type, the recording medium type, and the recording mode. There is provided an image recording apparatus having means for setting and storing parameters.

  With these devices, the color mixture determination method and the image recording method are executed, and a high-quality image that avoids color mixture can be obtained.

  As described above, according to the color mixing determination method and the image recording method and apparatus according to the present invention, it is possible to determine the color mixing of the ink ejected onto the recording medium and landed on the surface of the recording medium, thereby preventing the color mixture. Image recording is possible.

  Hereinafter, a color mixing determination method, an image recording method, and an apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram including a partial block diagram showing an outline of an ink jet recording apparatus as an image recording apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, the ink jet recording apparatus 10 mainly includes a plurality of print heads 12Y provided for each ink color (yellow (Y), cyan (C), magenta (M), black (K)). , 12C, 12M, and 12K, a conveyance unit 18 that conveys the recording paper 16 that is a recording medium from the paper supply unit 14 to the print head 12Y, and the fixing / curing unit 20 that fixes the ink ejected on the recording paper 16. (Fixing means) and the like.

  In the recording paper 16 shown in FIG. 1, the roll paper (continuous paper) loaded in the magazine 22 of the paper supply unit 14 is cut into a predetermined length by the cutter 24 and used. A plurality of magazines with different etc. may be provided. Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  In the case of an apparatus configuration using roll paper, a cutter 24 is provided as shown in FIG. 1, and the roll paper is cut into a desired size by the cutter 24. Note that the cutter 24 is not necessary when cut paper is used.

  In the present embodiment, an information recording body such as a bar code or a wireless tag recording paper type information is attached to the medium type detection notch 22a of the magazine 22 for reading the information of the information recording body. Medium type detection means 25 is installed. As will be described later, using the information read by the medium type detection unit 25, control parameters optimum for image recording on the recording medium are set and image recording is performed. In this specification, the term “image recording” includes not only image data but also text data recording.

  The recording paper 16 delivered from the magazine 22 retains curl due to having been loaded in the magazine 22. Although not shown, in order to remove this curl, a decurling unit is provided to heat the recording paper 16 with a heating drum or the like in a direction opposite to the curl direction of the magazine, and the curled surface slightly weakens outward. It is more preferable to control the heating temperature in such a manner.

  The transport unit 18 has a structure in which an endless belt 29 is wound between rollers 26 and 27, and is configured such that at least a portion facing the nozzle surface such as the print head 12K forms a flat surface (flat surface). ing.

The belt 29 has a width that is greater than the width of the recording paper 16, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in FIG. 1, an adsorption chamber 30 is provided at a position facing the nozzle surfaces of the print heads 12Y, 12C, 12M, and 12K inside the belt 29 that is stretched between the two rollers 26 and 27. The suction chamber 30 is sucked by the fan 32 to be a negative pressure, whereby the recording paper 16 on the belt 29 is sucked and held.

  When the power of the motor 34 is transmitted to at least one of the rollers 26 and 27 around which the belt 29 is wound (for example, the left roller 26 as shown in FIG. 1), the belt 29 rotates counterclockwise in FIG. The recording paper 16 held on the belt 29 is transported from the right to the left in FIG.

  FIG. 2 shows an enlarged plan view of the vicinity of the print heads 12Y, 12C, 12M, and 12K. As shown in FIG. 2, the print heads 12Y, 12C, 12M, and 12K correspond to the respective colors (YCMK), and each have a nozzle row 13Y, 13C, 13M, and 13K in which a plurality of nozzles are arranged. 16 in which the longitudinal direction of each of the print heads 12Y, 12C, 12M, and 12K is arranged in the paper width direction orthogonal to the conveyance direction of the recording paper 16 (the direction indicated by the arrow V in the figure). It is a full-line type head having a length corresponding to. Also, fixing / curing means 20 having a length corresponding to the entire width of the recording paper 16 is disposed between the print heads 12Y, 12C, 12M, and 12K.

  Here, the full-line type head includes a type in which a plurality of short recording heads are arranged in the paper width.

In each of the print heads 12Y, 12C, 12M, and 12K, a plurality of nozzle rows 13Y, 13C, 13M, and 13K are arranged, and the nozzles are arranged in a two-dimensional matrix. Further, the distance between the nozzle rows on the upstream side in the transport direction of the recording paper 16 of each of the print heads 12Y, 12C, 12M, and 12K is referred to as the inter-nozzle distance S of each of the print heads 12Y, 12C, 12M, and 12K. Specifically, as shown in FIG. 2, the distance between the nozzle row 13Y on the upstream side in the transport direction of the print head 12Y and the nozzle row 13C on the upstream side in the transport direction of the print head 12C is set between these two colors Y and C. This is referred to as an inter-nozzle row distance _SCY, and similarly, the inter-nozzle row distance S _MC between the nozzle row 13C of the print head 12C and the nozzle row 13M of the print head 12M, and the nozzle row 13M of the print head 12M and the print head 12K. defining of the nozzle row separation distance S _KM between the nozzle rows 13K similarly. These inter-nozzle row distances S _CY , S _MC , and S _KM are variable and can be freely controlled.

  As shown in FIG. 1 or FIG. 2, Y (yellow), C (cyan), M (magenta), and K (black) from the upstream side along the conveyance direction of the recording paper 16 (right to left in the figure). Print heads 12Y, 12C, 12M, and 12K corresponding to the respective color inks are arranged in order. A color image can be formed on the recording paper 16 by ejecting the color inks from the print heads 12Y, 12C, 12M, and 12K while the recording paper 16 is transported by the transport unit 18.

  In order to perform image recording while transporting the recording paper 16 in this way, ejection of two different color dots corresponding to the recording speed when recording data (print data) is recorded on the recording paper 16 at the transport speed of the recording paper 16. The time difference is almost determined. Therefore, if the conveyance speed of the recording paper 16 is increased and ink is ejected from the print heads 12Y, 12C, 12M, and 12K and recording is performed accordingly, this ejection time difference can be shortened (recording speed is increased).

  In this embodiment, the dot ejection time difference can be changed by controlling the conveyance speed of such a recording medium or by changing the distance between the heads that form two-color dots.

  As described above, according to the print heads 12Y, 12C, 12M, and 12K in which full line heads that cover the entire paper width are provided for each ink color, the recording paper 16 and the print heads 12Y, 12C in the paper transport direction. , 12M and 12K can be recorded at high speed on the entire surface of the recording paper 16 only by performing an operation of relatively moving the images 12M and 12K once (that is, by one scanning).

  Further, an ink type detection means 28 (see FIG. 1) for detecting the type of ink is provided in the vicinity of an ink tank (not shown) that supplies each color ink to each print head 12Y, 12C, 12M, 12K. Yes. The ink type detection unit 28 is not particularly limited. For example, in the case of a cartridge-type ink tank, the ink type detection unit 28 may be configured to read an ID indicating the ink type from an information medium or the like attached to the cartridge.

  In this example, the configuration of the standard colors of YCMK (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink and dark ink are added as necessary. May be. For example, it is possible to add a print head that discharges light ink such as light cyan and light magenta.

  Returning to FIG. 1 again, the ink ejection of the print heads 12Y, 12C, 12M, and 12K is controlled by the head driver 36. The fixing / curing means 20 provided between the print heads 12Y, 12C, 12M, and 12K fixes the ink discharged from the print heads 12Y, 12C, 12M, and 12K onto the recording paper 16, and is used. A suitable means is used according to the ink to be used.

  Here, the term “fixing” refers to the content of both the penetration of the ink landed on the recording paper 16 into the fiber of the paper and the drying of the ink from the surface, and the ink landed on the surface of the recording paper 16 Says that the droplet no longer exists. For example, in the case of water-based ink, examples of the fixing / curing unit 20 include a device that applies thermal energy such as a heater, an infrared irradiation device, or a fan (hot air fan) that blows wind (hot air). The devices for fixing these inks may be used alone or in combination.

  As shown in FIG. 1 or FIG. 2, the fixing / curing means 20 is installed between the four print heads 12Y, 12C, 12M, and 12K, and fixes the ink ejected from each print head. Even if ink is ejected on or near the print head, each ink does not mix.

In this embodiment, the distance between the nozzle rows of the print heads 12Y, 12C, 12M, and 12K for each color (the distance S _CY between the nozzle rows 13Y and 13C of the print heads 12Y and 12C, and the nozzle rows of the print heads 12C and 12M). Control of the distance S _MC between 13C and 13M, the distance S _KM between the nozzle arrays 13M and 13K of the print heads 12M and 12K, control of the relative conveyance speed (discharge time difference) of the recording paper 16, and the fixing / curing means 20 By controlling at least one of the three types of control amount control of the fixing time by controlling the fixing energy of the ink, printing is performed at high speed while preventing color mixing of the ink. It is to make.

  In the present embodiment, when the distance between the nozzle rows is actually made variable, the distance between the nozzle rows is made variable by changing the distance for each print head. Is the same as controlling the distance between the print heads.

Further, in the present embodiment, when the color mixing is avoided by controlling the distance between the nozzle rows (distance between the print heads), the relative conveyance speed (difference in discharge time), and the fixing time (fixing energy), each recording that can be recorded most quickly. By setting the optimum value of the control amount as a parameter, it is possible to prevent color mixing and simultaneously record at high speed.

  For this reason, the inkjet recording apparatus 10 according to the present embodiment includes, in addition to the above-described ones, as a means related to the color mixture avoidance control, first, a color mixture determination unit (color mixture determination device) 35 that determines a color mixture, and between nozzle rows An inter-head distance control means 38 for controlling the distance (distance between print heads) and a relative conveyance speed control means 40 for controlling the discharge time difference by controlling the relative conveyance speed V of the recording paper 16 (hereinafter simply referred to as conveyance control means). 40), a fixing control means 42 for controlling the fixing energy of the fixing / curing means 20 to control the fixing time of the ink, and a frequency for aligning the dot pitch of the recorded image when the relative conveyance speed is varied. The control means 44 and parameter setting means 46 for setting control parameters so that each control means performs optimal control. In addition, an encoder 41 for detecting the relative conveyance speed V is installed on the roller 26 in order for the conveyance control means 40 to control the relative conveyance speed V.

  Although described in detail later, the color mixture determination unit 35 outputs a color mixture determination print output unit 48 for outputting a color mixture determination print on which a color mixture determination pattern (color mixture determination patch) for determining color mixture is formed. The image forming apparatus includes a densitometer 45 that measures the density of a print color mixing determination patch, a color mixing determination unit 49 that performs color mixing determination using the measurement result of the densitometer 45, and the like. This color mixing determination method will be described later in detail.

The head-to-head distance control means 38 moves the print heads 12Y, 12C, 12M, and 12K of the respective colors in the paper transport direction to determine the distance between adjacent print heads (print adjacent to the nozzle row formed on one print head. By changing the inter-nozzle distances S _CY , S _MC , S _KM, etc. with the nozzle row formed on the head, ink from each print head 12Y, 12C, 12M, 12K (nozzle row) to the recording paper 16 It controls the discharge timing.

  For example, in order to increase the effect of preventing color mixing, the distance between the nozzle rows is increased so that the ink ejected from one nozzle row is ejected from the nozzle row of the next print head. In between, try to dry (fix) more. The specific means for changing the distance between the nozzle rows is not particularly limited. For example, the print heads 12Y, 12C, 12M, and 12K are arranged on rails provided at both ends of the full-line head by a ball screw or the like. May be movable.

  The conveyance control unit 40 controls the number of rotations of the motor 34 based on the detection signal of the rotary encoder 41. At this time, when the optimum relative conveyance speed V is set by parameters as will be described later, the rotation of the motor 34 is controlled so that the relative conveyance speed of the recording paper 16 becomes that speed.

  For example, if the fixing / curing unit 20 is a device that applies heat, the fixing control unit 42 controls the thermal energy applied by changing the set temperature, or changes the rotational speed of a fan that sends hot air, for example. Thus, the fixing time t1 is controlled by controlling the fixing energy of the ink on the recording paper 16.

  When the relative conveyance speed V of the recording paper 16 is changed, the frequency control unit 44 controls the ink ejection timing from each of the print heads 12Y, 12C, 12M, and 12K to adjust the recording image to a predetermined dot. The image quality is kept constant so that the image has a pitch.

The parameter setting unit 46 includes at least one of a head distance control unit 38, a conveyance control unit (discharge time difference control unit) 40, and a fixing control unit 42 based on the color mixing determination result determined from the density measurement result of the color mixing determination print. This is for setting optimum parameters for each control means for control.

  In the inkjet recording apparatus 10 according to the embodiment described above, the fixing control unit 42 controls the fixing / curing unit 20 to fix the ink ejected on the recording paper 16 to prevent color mixing. However, the curing means 21 such as an irradiation device for irradiating electromagnetic radiation to the UV curing ink or generally electromagnetic radiation curable ink that causes a polymerization reaction by being irradiated with UV light and is cured is fixed. -It may be installed in place of the curing means 20 and controlled by the curing control means 43 to cure the ink and prevent color mixing of the ink.

  Here, “curing” means that the ink component is hardened and fixed on the surface of the recording paper 16 by chemical change caused by light irradiation such as electromagnetic radiation or application of heat. As the curing means 21, for example, in the case of UV curable ink, a UV light irradiation device, a halogen lamp, an irradiation device such as an LED laser, and the like are exemplified. In the case of other solid ink, a cooling device such as Peltier or water cooling may be used.

  Hereinafter, the case where the fixing control unit 42 and the fixing / curing unit 20 are used will be described. However, as shown in FIG. 1, the curing control unit 43 and the curing unit 21 may be used instead. The control is exactly the same. That is, the curing control unit 43 may control the curing time t2 by changing the irradiation light amount or irradiation region of the curing unit 21 and controlling the curing energy of the ink on the recording paper 16 (recording medium). By curing the ink droplets on the surface, the presence of the surface ink droplets can be eliminated and color mixing can be prevented.)

  FIG. 3 is a principal block diagram showing the system configuration of the inkjet recording apparatus 10. The inkjet recording apparatus 10 includes a communication interface 50, a system controller 52, an image memory 54, a motor driver 56, a heater driver 58, a print control unit 60, an image buffer memory 62, a head driver 36, and the like.

  The communication interface 50 is an interface unit that receives image data (recording data) sent from the host computer 64. As the communication interface 50, a serial interface such as USB, IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. In this part, a buffer memory (not shown) for speeding up communication may be mounted. Image data sent from the host computer 64 is taken into the inkjet recording apparatus 10 via the communication interface 50 and temporarily stored in the image memory 54. The image memory 54 is not limited to a memory made of a semiconductor element, and a magnetic medium such as a hard disk may be used.

  The system controller 52 is a control unit that controls each unit such as the communication interface 50, the image memory 54, the motor driver 56, the heater driver 58, and the like. The system controller 52 includes a central processing unit (CPU) and its peripheral circuits, and performs communication control with the host computer 64, read / write control of the image memory 54, and the like, as well as the motor 34 and heater 66 of the transport system. A control signal for controlling is generated.

  The motor driver 56 is a driver (drive circuit) that drives the motor 34 in accordance with an instruction from the system controller 52. The heater driver 58 is a driver that drives a heater 66 such as a post-drying unit (not shown) that dries the recording paper 16 after printing in accordance with an instruction from the system controller 52.

  The print control unit 60 has a signal processing function for performing various processes and corrections for generating a print control signal from the image data in the image memory 54 in accordance with the control of the system controller 52. A control unit that supplies a control signal (print data) to the head driver 36. The required signal processing is performed in the print control unit 60, and the ejection amount and ejection timing of the ink droplets of the print heads 12Y, 12C, 12M, and 12K are controlled via the head driver 36 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 60 includes an image buffer memory 62, and image data, parameters, and other data are temporarily stored in the image buffer memory 62 when image data is processed in the print control unit 60. In FIG. 3, the image buffer memory 62 is shown in a mode associated with the print control unit 60, but it can also be used as the image memory 54. Also possible is an aspect in which the print controller 60 and the system controller 52 are integrated and configured with a single processor.

  The head driver 36 drives the actuators of the print heads 12K, 12C, 12M, and 12Y of the respective colors based on the print data given from the print control unit 60. The head driver 36 may include a feedback control system for keeping the head driving condition constant.

In addition, the ink jet recording apparatus 10 according to the present embodiment also includes adjacent print heads (in this example, as shown in FIG. 1 or FIG. 2, the print heads 12Y and 12C, the print heads 12C and 12M, the print head 12M Head distance control means 38 for controlling the inter-head distances S _CY , S _MC , S _KM , the conveyance control means 40 for controlling the relative conveyance speed V of the recording paper 16, and the fixing / curing means. Fixing control means 42 for controlling the fixing time t1 of the ink ejected onto the recording paper 16 by controlling the fixing energy 20; frequency control for controlling the ink ejection frequency when the relative transport speed V is changed. Means 44, parameter setting means 46 for setting parameters for controlling each control means, and a mixture for outputting a color mixture judgment print described in detail later. A color mixture determination print output unit 48 that forms a determination pattern and outputs a color mixture determination print from the print heads 12Y, 12C, 12M, and 12K through the head driver 36, and a color mixture determination unit 49 that performs color mixture determination based on the density measurement result of the color mixture determination print. Etc.

  Here, the frequency control unit 44 and the color mixture determination print output unit 48 are provided in the print control unit 60 and are controlled by the system controller 52. As will be described in detail later, the color mixture determination means 49 is provided with an average value / standard deviation calculation means 51 for calculating a predetermined numerical value used for color mixture determination using a density profile obtained as a result of density measurement. It has been. Further, the system controller 52 is provided with a recording mode detecting means 53 for detecting the recording mode from the image data (recording data). Here, the recording mode indicates whether the recording data is composed only of text, only composed of image data, or includes both text and image data.

  Next, a method for determining color mixing and setting optimum parameters for preventing color mixing and high-speed recording for each control means will be described. For this purpose, the creation of a color mixture determination pattern for determining color mixture will be described first.

As shown in FIG. 1 or FIG. 2, the mixed color determination pattern is obtained by using two colors of ink (12Y and 12C, 12C and 12M, 12M and 12K) ejected from two adjacent print heads (12Y and 12C). In order to examine how Y (yellow) and C (cyan), C and M (magenta), and M and K (black)) are mixed, a conveyance speed V (corresponding to a discharge time difference or a recording speed) and It is created by recording the fixing energy E in a plurality of stages.

  FIG. 4 shows an example of the color mixture determination pattern. As shown in FIG. 4, the color mixture determination pattern 70 is recorded by changing the relative conveyance speed V and the fixing energy E in three stages of high (max), medium (mid), and low (low), respectively. For each combination of two adjacent inks, a patch 72 (mixed color determination patch) including nine mixed color determination patterns is formed. Here, the max of the three stages of the conveyance speed V and the fixing (curing) energy E is the maximum speed (or the maximum energy), mid is a middle value of about 2/3 of the maximum value, and low is 1/3 of the maximum value. The low value of the degree is shown.

  In this embodiment, the conveyance speed V is changed (the distance between the heads is constant), and the difference in ejection time between the two different color dots is changed, but the distance between the heads is changed (the conveyance speed V is constant). ) Patches may be formed by changing the discharge time difference.

  As shown in FIG. 5A, the patch 72 of the color mixture determination pattern 70 is obtained by arranging two colors (for example, C and M) side by side and printing (recording) them in a rectangular shape. In particular, the boundary portion 72a of two colors is overstruck with several hundred dots in order to examine mixed colors, as shown in an enlarged view in FIG.

  FIG. 6 shows how these two colors of ink are mixed. As shown in FIG. 6A, the Y ink 74 is ejected onto the recording paper 16, and the C ink 76 is ejected so as to partially overlap with a slight shift. The Y ink 74 penetrates into the recording paper 16 as indicated by reference numeral 74a, and drying progresses on the surface of the recording paper 16.

  At this time, if the C ink 76 is ejected while the Y ink 74 is not yet fixed, color mixing (bleeding) occurs in the overlapping portion 75. Then, as shown in FIG. 6B, the fixing is performed in a state where both colors are mixed (bleeding) in the overlapping portion 75.

  The color mixture determination print output means 48 generates data of the color mixture determination pattern 70 as shown in FIGS. 4 and 5, or is called from a predetermined memory and sends the data of the color mixture determination pattern 70 through the head driver 36 to the print head 12Y, This is sent to 12C, 12M, and 12K and output as a color mixture determination print.

  The density of each patch 72 (color mixing determination patch) of the output color mixing determination print is measured by the densitometer 45. The principle of this concentration measurement is shown in FIG.

  As shown in FIG. 7, the minute spot light 91 emitted from the RGB light emitting element 90 is applied to a measurement point on the medium 92, and the reflected light is received by a light receiving element 93 such as a CCD element. Measurements can be made. At this time, as the RGB light emitting element, for example, a combination of a halogen lamp and a filter can be considered.

  Alternatively, for example, as shown in FIG. 7B, the area light 95 emitted from the RGB light emitting element 94 is applied to the measurement point of the medium 92, and the reflected light is condensed on the area CCD 97 by the lens 96 and measured. You may do it.

In this measurement, as shown in FIG. 5A, the boundary portion 72a of two colors is divided into N equal parts (for example, 10 equal parts or more) in the vertical direction of the figure, and scanned to the left and right as indicated by the arrow F Is done by doing. More specifically, this density measurement is performed by measuring a region approximately three times as large as the dot overlapped portion (see FIG. 5B) indicated by an arrow D in FIG. This is done by scanning.

  The result of measurement by the densitometer 45 is sent to the color mixture determination means 49. An example of the density measurement result of each patch 72 (color mixing determination patch) of the color mixing determination print that outputs the color mixing determination pattern 70 is shown in a graph in FIG. One graph showing such a density profile is obtained for the scan along each arrow F in FIG. The solid line indicates the density when the mixed color (bleeding) of C ink and M ink occurs, and the alternate long and short dash line indicates the density in an ideal state without mixed color.

The average value / standard deviation calculating means 51 of the color mixture determining means 49 is a predetermined threshold for the maximum density M _max of M, for example, a predetermined threshold for the density point P _{M of} 60% and the maximum density C _max of C. , for example, calculates the distance d between the 60% density point P _C, obtained for one patch 72, the longitudinal direction N equal parts (10 or more equal parts) were each scan performed at a plurality of positions A standard deviation σd and an average value av (d) of each distance d are calculated. The smaller the standard deviation σd or the average value av (d) of the distance d, the less the color mixture.

  Then, as shown in FIG. 9, the color mixture determining means 49 sets a parameter for a combination of the conveyance speed V and the fixing energy E that minimizes at least one of the calculated standard deviation σd and average value av (d). Send to means 46.

  The parameter setting means 46 avoids color mixing of the two colors of ink on the recording paper 16 with a combination of the conveyance speed V and the fixing energy E that minimizes at least one of the standard deviation σd and the average value av (d). Set as an optimal parameter to do. The parameter setting unit 46 stores the parameters in association with the type of the recording paper 16 and the type of ink sent from the medium type detection unit 25 and the ink type detection unit 28.

  Here, the combination of the conveyance speed V and the fixing energy E that minimizes the standard deviation σd is selected in consideration of the link with visual color mixture, and the average value av (d) is minimized. This is because it is considered that the resolution reduction due to the color mixture is reflected in the average value av (d). In this way, color mixing can be minimized.

  Thus, if the distance S between the print heads is constant by setting the energy E (fixing energy or curing energy) with the least color mixture and the conveying speed V, the fixing time t1 or the curing energy based on the fixing energy E is set. S / V> t1 or S / V> t2 can be satisfied with respect to the curing time t2 by E.

  Hereinafter, the operation of the present embodiment will be described along the flowchart of FIG.

  First, in step S100 of FIG. 15, a magazine 22 for supplying the recording paper 16 to the inkjet recording apparatus 10 is loaded. As described above, an information recording body on which information such as the type of the loaded recording paper 16 is recorded is attached to the magazine 22 in the medium type detection notch 22a. read. Information read by the medium type detection unit 25 is sent to the parameter setting unit 46. On the other hand, the ink type detection unit 28 detects the ink type, and the detected ink type information is similarly sent to the parameter setting unit 46.

In the next step S110, the parameter setting means 46 determines whether the optimum parameter corresponding to the sent medium type information or the like has already been set and stored. If there is an optimum parameter corresponding to the medium type or the like, the process proceeds to step S120, and the optimum parameter (conveying speed V, fixing (curing) energy E) stored in the parameter setting means 46 is called. Thus, they are set in the conveyance control means 40, the fixing control means 42, and the head distance control means 38, if necessary.

  On the other hand, if there is no optimum parameter corresponding to the detected medium type or the like, the process proceeds to step S130 in order to create a color mixture determination pattern for setting the optimum parameter. If the information recording medium is not attached to the magazine 22 or if it is attached but cannot be read by the medium type detecting means 25, for example, a dummy medium type is sent to the parameter setting means 46 to cope with it. Similarly, it is assumed that the optimum parameter does not exist, and the process proceeds to step S130.

  In step S130, the conveyance speed V (discharge time difference) and the fixing energy E are changed in a plurality of steps for each adjacent print head (12Y and 12C, 12C and 12M, 12M and 12K) by the method described above. Each patch is output to create a color mixture determination pattern as shown in FIG.

  Next, in step S140, the density meter 45 measures the density of each patch of the color mixture determination pattern, particularly the boundary portion, and collects a density profile as shown in FIG. The measured density profile is sent to the color mixture determining means 49.

  In step S150, the average value / standard deviation calculating unit 51 of the color mixture determining unit 49 uses the respective density profiles as described above to use the average value av () of the distances between the density points of 60% of the maximum density value of each color. d) and the standard deviation σd are calculated, a combination of the conveying speed V and the fixing energy E that minimizes at least one of them is selected, and this is set and stored as an optimum parameter in the parameter setting means 46. deep.

  In step S160, image recording (printing) is performed using these optimum parameters. In addition, if it is determined in step S110 that an optimum parameter exists and this optimum parameter is set in step S120, printing is performed in step S160.

  As described above, according to the present embodiment, the optimum parameters for avoiding color mixing are set in advance according to the type of the recording medium and the ink, and then only the type of the recording medium is detected. Color mixing can be avoided easily. Even if the type of the recording medium cannot be detected, a color mixture determination pattern is created and a color mixture determination print is output, and this is subjected to density measurement to obtain a density profile. By setting, it is possible to avoid color mixing and perform high-quality image recording.

  In the present embodiment, the following method is also conceivable as processing after the density measurement of the color mixture determination pattern 70 by the densitometer 45.

  That is, the density profile measured in the same manner as above with the densitometer 45 is sent to the color mixture determination means 49, and the color mixture determination means 49 uses a predetermined threshold (for example, a density point of 60% of the maximum density, etc.) in the density profile of two colors. ) Is calculated, and a standard deviation σd and an average value av (d) of the distance d in a plurality of concentration profiles obtained by a plurality of measurements are calculated.

Then, for the calculated standard deviation σd and average value av (d) of each distance d, a target value having a correspondence as shown in FIG. 11 (for example, the average value of the distance is shown in FIG. 8), correction coefficients a1 and a2, and weighting coefficients b1 and b2. The correction coefficient and the weighting coefficient are applied to an element (factor) for calculating an evaluation value for determining the color mixture described below.

  Here, the weighting factors b1 and b2 are modes in which a combination of character data and an image is recorded, for example, as shown in FIG. 12, according to the recording mode detected by the recording mode detecting means 53 based on the image data (recording data). And determined in accordance with the mode for recording only the image. For example, in the mode in which both text and image are recorded, the weighting factors b1 and b2 are equal to b1 = b2 = 1, and in the image mode, b1 = 2, b2 = 1 and the weighting factor b1. Set a larger value.

  Then, using these values, the color mixture is determined by the color mixture determination function given by the following equation (1).

Color mixing determination function f = σd × a1 × b1 + | av (d) −D | × a2 × b2
... (1)
That is, the value of the color mixture determination function f is used as an evaluation value for determining color mixture, and it is determined that the smaller the value, the less color mixture. Therefore, the parameter setting unit 46 sets the combination of the relative conveyance speed V and the fixing energy E corresponding to the patch 72 that minimizes the value of the color mixture determination function f as an optimum parameter for color mixture avoidance.

Further, as described above, a color mixture determination pattern is created, and this is used to associate an optimum parameter that satisfies the inequality S / V> t1 or S / V> t2 and avoids color mixture with a recording medium type. In addition to the above-described method, the head distance S (S _CY , S _MC , S _KM ), the conveyance speed V, the fixing time t 1 or the curing time t 2 (fixing energy or curing energy) is directly satisfied. By controlling the color mixing, color mixing may be avoided. In this case, the relationship between the fixing energy and the fixing time t1 or the relationship between the curing energy and the curing time t2 is acquired in advance for each recording medium type.

The head distance S (distance S _CY between the print heads 12Y and 12C, distance S _MC between the print heads 12C and 12M, and distance S _KM between the print heads 12M and 12K) is controlled by the head distance control means 38. . For example, when the fixing time t1 is determined, the head-to-head distance S needs to be increased when the transport speed V is increased in order to shorten the discharge time difference.

  Further, when the print head 12Y or the like is formed of a long line head corresponding to the entire width direction of the recording paper 16, the head arrangement on the downstream side in the transport direction is adjusted according to the decrease in the osmotic pressure of the recording paper 16, and the head-to-head distance. You may make it arrange | position so that S may be lengthened. Further, the fixing / curing unit 20 may be controlled by the fixing control unit 42 in accordance with the ink penetration amount of the recording paper 16 to enhance drying.

  In this embodiment, the arrangement of the print heads 12Y, 12C, 12M, and 12K uses a head that uses ink with slow penetration and drying and a long fixing time, or ink with a large amount of curing energy. It is preferable that the head is disposed on the upstream side in the transport direction. Further, when printing is performed by changing the distance S between the heads or by changing the conveyance speed V, the ejection frequency of each of the print heads 12Y, 12C, 12M, and 12K is controlled so that the recorded image has a predetermined dot pitch. Is preferred. The discharge frequency is controlled by the frequency control unit 44 in response to the conveyance speed information from the conveyance control unit 40.

  Next, a second embodiment of the present invention will be described.

  FIG. 13 is a block diagram illustrating a control unit related to the color mixture avoidance control including a plan view illustrating an enlarged vicinity of the print head of the inkjet recording apparatus 110 according to the second embodiment of the present invention.

  As shown in FIG. 13, the print head 112 of the second embodiment is a shuttle type head that records an image while reciprocating in the width direction of the recording paper 116. At this time, the print head 112 performs image recording only when moving in one direction from one end in the width direction of the recording paper 116 to the other end, and after moving to the other end, the one on this side again. When returning to the end, image recording is not performed.

On the print head 112, nozzle rows 112Y, 112C, 112M, and 112K for each color that discharge ink of each color of YMCK are parallel to a direction substantially perpendicular to the moving direction of the print head 112 (width direction of the recording paper 116). Are arranged side by side. The nozzle rows 112Y, 112C, 112M, 112K for each color are the distances S between adjacent nozzle rows in this order from the upstream side in the moving direction of the print head 112 during recording (the nozzle row between the nozzle row 112Y and the nozzle row 112C). during the distance S _CY, nozzle array 112C and the nozzle row 112M between the nozzle row separation distance S _MC, are arranged in the nozzle row separation distance S _KM) capable of changing the state between the nozzle rows 112M and the nozzle row 112K.

  Fixing / curing means 120 is disposed in parallel to the downstream sides of the nozzle rows 112Y, 112C, 112M, and 112K.

  The recording paper 116 is stationary when the print head 112 moves from one end to the other end in the width direction of the recording paper 116 while recording. When the print head 112 finishes recording from one end to the other end in the width direction of the recording paper 116 and returns to the one end on this side again, the recording head 116 has now recorded on the recording paper 116. The recording paper 116 is conveyed in a direction perpendicular to the width direction of the recording paper 116 by an amount corresponding to the width of the band-like region in the width direction of the recording paper 116 (width of the nozzle row 112Y, etc.).

  Thus, in this embodiment, since the print head 112 is a shuttle type head, unlike the first embodiment described above, the recording paper 116 is stationary and only the print head 112 moves during image recording. The moving direction of the print head 112 corresponds to the relative conveyance direction (the recording paper 16 and the print head 12) in the first embodiment.

  Further, as shown in FIG. 13, the inkjet recording apparatus 110 of the present embodiment also has an inter-nozzle row distance control means 138 (in the first embodiment) as means for color mixture avoidance control, as in the first embodiment. Corresponding to the head-to-head distance control means 38), nozzle driver 136 (corresponding to the head driver 36 of the first embodiment), conveyance control means 140, fixing control means 142, frequency control means 144, parameter setting means 146, color mixture determination print output Means 148, a densitometer 145, a color mixture determination means 149, and the like. The nozzle driver 136 controls ink ejection in each nozzle row and corresponds to the head driver 36 of the first embodiment.

In this embodiment, the inter-nozzle row distance control means 138 is a distance between the nozzle rows 112Y, 112C, 112M, and 112K (specifically, the distance S _CY between the nozzle rows 112Y and 112C, and the nozzle rows 112C and 112M). the distance between S _MC, the distance S _KM) itself between the nozzle rows 112M and 112K variable.

  Further, the transport control unit 140 controls the moving speed (discharge time difference) V during recording of the print head 112 as a relative transport speed.

  The functions of the fixing control unit 142, the frequency control unit 144, the parameter setting unit 146, the color mixture determination print output unit 148, and the color mixture determination unit 149 are the same as those in the first embodiment described above, and detailed description thereof is omitted.

  Eventually, in the present embodiment, the full line type head of the first embodiment is changed to a shuttle type head, and the nozzle row for each color is arranged on a separate line head in the first embodiment. The difference is that the nozzle rows are arranged on one shuttle type head. The distance between the nozzle rows is variable and the relationship between the print head (nozzle row) and the relative conveyance direction of the recording medium is the same.

  Therefore, also in this embodiment, the color mixture avoidance control similar to that in the first embodiment is possible, and the operation of this embodiment is basically the same as that in the first embodiment. The operation of this embodiment will be briefly described as follows.

  The color mixture determination print output means 148 creates a color mixture determination pattern as shown in FIGS. 4 and 5 and sends this data to the print head 112 via the nozzle driver 136 to output a color mixture determination print. The density measurement unit 145 measures the density of the output color mixture determination print color mixture determination patch. The density profile obtained by the measurement is sent to the color mixture determining means 149. In the color mixture determination means 149, a distance d between points that becomes a predetermined threshold (for example, a density point of 60% with respect to the maximum density) in the density profile of two colors is calculated, and a plurality of densities obtained by a plurality of measurements are calculated. A standard deviation σd and an average value av (d) of the distance d in the profile are calculated, and for example, a conveyance speed and fixing energy at which at least one of these values av (d) and σd is minimized are extracted, and parameters are set. Sent to means 146.

The parameter setting means 146 sets and stores these values for each control means as control parameters for each control means. Thus the relative conveying speed of the printing head 112 (the moving speed of the recording paper 116 width direction) V, each nozzle row separation distance S _CY, S _MC, at least one of S _KM, fixing energy E of fixing and curing means 120 The above is preset. When the optimum parameters for color mixture avoidance control are set in this way, the print head 112, which is a shuttle type head, is driven to perform printing.

  Next, a third embodiment of the present invention will be described.

  FIG. 14 is a schematic configuration diagram including a partial block diagram showing an outline of an ink jet recording apparatus as a third embodiment of the present invention.

  As shown in FIG. 14, the inkjet recording apparatus 210 mainly includes a plurality of print heads 212Y provided for each ink color (yellow (Y), cyan (C), magenta (M), black (K)). 212C, 212M, and 212K, a transport unit 218 that transports the recording paper 216 that is a recording medium from the paper supply unit 214 to the print head 212Y, and the like, and a fixing / curing unit 220 that fixes the ink ejected on the recording paper 216. And so on.

  In the case of the recording paper 216 shown in FIG. 14, the roll paper (continuous paper) loaded in the magazine 222 of the paper supply unit 214 is cut into a predetermined length by the cutter 224 and used. A plurality of magazines with different etc. may be provided. Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  In the case of an apparatus configuration using roll paper, a cutter 224 is provided as shown in FIG. 14, and the roll paper is cut into a desired size by the cutter 224. Note that the cutter 224 is not necessary when cut paper is used.

The recording paper 216 delivered from the magazine 22 retains curl due to having been loaded in the magazine 222. Although not shown, in order to remove the curl, a decurling unit is provided to heat the recording paper 216 with a heating drum or the like in the direction opposite to the curl direction of the magazine, and the curled surface slightly weakens outward. It is more preferable to control the heating temperature in such a manner.

  The transport unit 218 has a structure in which an endless belt 229 is wound between rollers 226 and 227, and is configured such that at least a portion facing the nozzle surface such as the print head 212K forms a flat surface (flat surface). ing.

  The belt 229 has a width that is greater than the width of the recording paper 216, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in FIG. 14, an adsorption chamber 230 is provided at a position facing the nozzle surfaces of the print heads 212Y, 212C, 212M, and 212K inside the belt 229 that is stretched between the two rollers 226 and 227. The suction chamber 230 is sucked by the fan 232 to be a negative pressure, whereby the recording paper 216 on the belt 229 is sucked and held.

  When the power of the motor 234 is transmitted to at least one of the rollers 226 and 227 around which the belt 229 is wound (for example, the left roller 226 as shown in FIG. 14), the belt 229 rotates counterclockwise in FIG. , And the recording paper 216 held on the belt 229 is conveyed from the right to the left in FIG.

  The print heads 212Y, 212C, 212M, and 212K correspond to the respective colors (YCMK), and each has a nozzle row in which a plurality of nozzles are arranged in the same manner as in the first embodiment described above, and bears the entire width of the recording paper 216. As described above, the print heads 212Y, 212C, 212M, and 212K are arranged in the longitudinal direction in the width direction of the recording paper 216, thereby forming a full-line head having a length corresponding to the maximum paper width. Also, fixing / curing means 220 having a length corresponding to the entire width of the recording paper 216 is disposed between the print heads 212Y, 212C, 212M, and 212K.

In each of the print heads 212Y, 212C, 212M, and 212K, a plurality of nozzle rows (not shown) are arranged, and the nozzles are arranged in a two-dimensional matrix. The distance between the nozzle row upstream of the print head 212Y in the transport direction and the nozzle row upstream of the print head 212C in the transport direction is referred to as the inter-nozzle row distance S _CY between these two colors Y and C. Similarly, Similarly, the inter-nozzle row distance S _MC between the nozzle row of the print head 12C and the nozzle row of the print head 12M and the inter-nozzle row distance S _KM between the nozzle row of the print head 12M and the nozzle row of the print head 12K are similarly set. Define. These inter-nozzle row distances S _CY , S _MC , and S _KM are variable and can be freely controlled.

  As shown in FIG. 14, each color ink is applied in the order of Y (yellow), C (cyan), M (magenta), and K (black) from the upstream side along the conveyance direction (right to left in the drawing) of the recording paper 216. Corresponding print heads 212Y, 212C, 212M, and 212K are arranged. A color image can be formed on the recording paper 216 by ejecting the color inks from the print heads 212Y, 212C, 212M, and 212K while the recording paper 216 is transported by the transport unit 218.

  Each print head 212Y, 212C, 212M, 212K is controlled to eject ink by a head driver 236. The fixing / curing means 220 provided between the print heads 212Y, 212C, 212M, and 212K fixes the ink ejected from the print heads 212Y, 212C, 212M, and 212K onto the recording paper 216. A suitable means is used according to the ink to be used.

  As shown in FIG. 14, the fixing / curing means 220 is installed between each of the four print heads 212Y, 212C, 212M, and 212K, fixes the ink ejected from each print head, and then the next print head. Therefore, even if ink is ejected onto or near the ink, the inks do not mix.

In the present embodiment, the control of the distance (S _CY , S _MC , S _KM ) between the nozzle rows of the print heads 212Y, 212C, 212M, and 212K for each color, the control of the (relative) transport speed of the recording paper 216, and the fixing. -By controlling at least one of the three types of control amount control of fixing time by controlling the fixing energy of ink in the curing unit 220, high speed while preventing ink color mixing It is intended to record with.

  In the present embodiment, when the distance between the nozzle rows is actually made variable, the distance between the nozzle rows is made variable by changing the distance for each print head. Is the same as controlling the distance between the print heads.

  Furthermore, in this embodiment, when controlling the distance between nozzle rows (distance between print heads), the relative conveyance speed and the fixing time (fixing energy) to avoid color mixing, the optimum amount of each control amount that can be recorded most quickly. By setting the value as a parameter, it is possible to prevent color mixing and simultaneously record at high speed.

  For this reason, the ink jet recording apparatus 210 according to the present embodiment, in addition to the above-described one, is a nozzle row distance control unit 238 that controls the distance between nozzle rows (distance between print heads) as means for color mixture avoidance control. Relative conveyance speed control means 240 (hereinafter simply referred to as conveyance control means 240) for controlling the relative conveyance speed V of the recording paper 216 and fixing energy of the fixing / curing means 220 are controlled to control the ink fixing time. Fixing control means 242, frequency control means 244 for aligning the dot pitch of a recorded image when the relative conveyance speed is varied, parameter setting means for setting control parameters so that each control means performs optimum control H.246. In addition, an encoder 241 for detecting the relative conveyance speed V is installed on the roller 226 so that the conveyance control unit 240 controls the relative conveyance speed V.

The inter-nozzle row distance control means 238 moves the print heads 212Y, 212C, 212M, and 212K of the respective colors in the paper transport direction and is adjacent to the distance between adjacent print heads (adjacent to the nozzle row formed on one print head. By changing the inter-nozzle distances S _CY , S _MC , S _KM, etc. with the nozzle rows formed on the print head, the print heads 212Y, 212C, 212M, 212K (nozzle rows) can be transferred to the recording paper 216. It controls ink discharge timing.

  The conveyance control unit 240 controls the number of rotations of the motor 234 based on the detection signal of the rotary encoder 241. At this time, when the optimum relative conveyance speed V is set by parameters as will be described later, the rotation of the motor 234 is controlled so that the relative conveyance speed of the recording paper 216 becomes that speed.

  For example, if the fixing / curing unit 220 is a device that applies heat, the fixing control unit 242 controls the thermal energy applied by changing the set temperature, or changes the rotational speed of a fan that sends hot air, for example. Thus, the fixing time t1 is controlled by controlling the fixing energy of the ink on the recording paper 216.

  When the relative conveyance speed V of the recording paper 216 is changed, the frequency control unit 244 controls the ink ejection timing from each of the print heads 212Y, 212C, 212M, and 212K in accordance with the change so that the recorded image has a predetermined dot. A pitch image is obtained.

  The operator visually determines the color mixture of the ink by the color mixture determination print described later output from the inkjet recording apparatus 210, and the determination result is input from the color mixture determination result input means such as the keyboard of the operation panel installed in the inkjet recording apparatus 210. input. The parameter setting unit 246 sets an optimum parameter for each control unit in order to control at least one of the inter-nozzle distance control unit 238, the conveyance control unit 240, and the fixing control unit 242 based on the input color mixture determination result. Is for.

  In the inkjet recording apparatus 210 according to the above-described embodiment, the fixing control unit 242 controls the fixing / curing unit 220 to fix the ink ejected on the recording paper 216 to prevent color mixing. However, for example, a UV curable ink that undergoes a polymerization reaction upon being irradiated with UV light, or generally an electromagnetic radiation curable ink is used, and the curing means 221 such as an irradiation device that irradiates the electromagnetic radiation thereto is fixed to the fixing means 221. -It may be installed in place of the curing unit 220 and controlled by the curing control unit 243 to cure the ink and prevent color mixing of the ink.

  Hereinafter, the case where the fixing control unit 242 and the fixing / curing unit 220 are used will be described. However, as shown in FIG. 14, the curing control unit 243 and the curing unit 221 may be used instead. The control is exactly the same. In other words, the curing control unit 243 may control the curing time t2 by controlling the curing energy of the ink on the recording paper 216 by changing, for example, the irradiation light amount or irradiation region of the curing unit 221.

  FIG. 15 is a principal block diagram showing the system configuration of the inkjet recording apparatus 210. The ink jet recording apparatus 210 includes a communication interface 250, a system controller 252, an image memory 254, a motor driver 256, a heater driver 258, a print control unit 260, an image buffer memory 262, a head driver 236, and the like.

  The communication interface 250 is an interface unit that receives image data sent from the host computer 264. A serial interface such as USB, IEEE1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied to the communication interface 250. In this part, a buffer memory (not shown) for speeding up communication may be mounted. Image data sent from the host computer 264 is taken into the inkjet recording apparatus 210 via the communication interface 250 and temporarily stored in the image memory 254. The image memory 254 is not limited to a memory made of semiconductor elements, and a magnetic medium such as a hard disk may be used.

  The system controller 252 is a control unit that controls each unit such as the communication interface 250, the image memory 254, the motor driver 256, the heater driver 258, and the like. The system controller 252 includes a central processing unit (CPU) and its peripheral circuits, and performs communication control with the host computer 264, read / write control of the image memory 254, etc., and a transport motor 234 and heater 266. A control signal for controlling is generated.

  The motor driver 256 is a driver (drive circuit) that drives the motor 234 in accordance with an instruction from the system controller 252. The heater driver 258 is a driver that drives a heater 266 such as a post-drying unit (not shown) that dries the printed recording paper 216 in accordance with an instruction from the system controller 252.

The print control unit 260 has a signal processing function for performing various processes and corrections for generating a print control signal from the image data in the image memory 254 according to the control of the system controller 252, and the generated print A control unit that supplies a control signal (print data) to the head driver 236. Necessary signal processing is performed in the print control unit 260, and the ejection amount and ejection timing of the ink droplets of the print heads 212Y, 212C, 212M, and 212K are controlled via the head driver 236 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 260 includes an image buffer memory 262, and image data, parameters, and other data are temporarily stored in the image buffer memory 262 when image data is processed in the print control unit 260. In FIG. 15, the image buffer memory 262 is shown in a mode associated with the print control unit 260, but it can also be used as the image memory 254. Also possible is an aspect in which the print controller 260 and the system controller 252 are integrated and configured with a single processor.

  The head driver 236 drives the actuators of the print heads 212K, 212C, 212M, and 212Y of the respective colors based on the print data given from the print control unit 260. The head driver 236 may include a feedback control system for keeping the head driving condition constant.

In addition, the ink jet recording apparatus 210 according to the present embodiment also includes adjacent print heads (in this example, as shown in FIG. 14, print heads 212Y and 212C, print heads 212C and 212M, and print heads 212M and 212K). The nozzle row distance control means 238 for controlling the inter-nozzle row distances S _CY , S _MC , S _KM , the conveyance control means 240 for controlling the relative conveyance speed V of the recording paper 216, and the fixing / curing means 220. Fixing control means 242 for controlling the fixing time t1 of the ink discharged onto the recording paper 216 by controlling the fixing energy of the ink, and the frequency control means for controlling the ink discharge frequency when the relative transport speed V is changed. 244, parameter setting means 246 for setting parameters for controlling each control means, and a color mixture determination process described in detail later. Printhead 212Y through the head driver 236 to form a color mixing evaluation pattern for outputting cement has 212C, 212M, the color mixing evaluation print output section 248 for outputting a color mixing evaluation print from 212K.

  Here, the frequency control unit 244 and the color mixture determination print output unit 248 are provided in the print control unit 260 and are controlled by the system controller 252.

  Next, a method of setting optimum parameters for preventing color mixing and high-speed recording for each control means will be described. For this purpose, the creation of a color mixture determination pattern for determining color mixture will be described first.

  The color mixture determination pattern is used by the operator to visually determine the color mixture. As shown in FIG. 14, two adjacent print heads 212Y and 212C, 212C and 212M, and 212M in the inkjet recording apparatus 210 are used. In order to determine how the two color inks (Y (yellow) and C (cyan), C and M (magenta), M and K (black)) discharged from the 212K nozzle row are mixed. The two colors of ink are recorded side by side while changing the relative conveyance speed V and the fixing energy E.

FIG. 16 shows an example of a pattern for determining color mixture visually. As shown in FIG. 16, the color mixture determination pattern 80 is recorded by changing the relative conveyance speed V and the fixing energy E in three stages of high (max), medium (mid), and low (low), respectively. For each combination of two adjacent ink colors, the patch 82 is formed of nine color mixture determination patterns. Here, the max of the three stages of the conveyance speed V and the fixing (curing) energy E is the maximum speed (or the maximum energy), mid is a middle value of about 2/3 of the maximum value, and low is 1 / of the maximum value.
A low value of about 3 is shown.

  Also, as shown in FIG. 16, numbers (symbols) such as YC01 to YC09, CM01 to CM09, and MK01 to MK09 are assigned to nine patches 82 for each combination of two colors. Used when setting parameters.

  Each patch 82 of the mixed color determination pattern 80 is a resolution chart in which two colors (for example, Y and C) are arranged side by side as shown in FIG. 17 and printed in a band shape (rectangular shape) that gradually becomes narrower. In particular, the boundary between the two colors is overprinted by several dots (1 to 2 dots) in order to check the mixed color. In addition, as shown in FIG. 17, for example, the width of each band-shaped region is initially reduced by 1 [mm] for each of Y and C, and the width is gradually reduced. ].

  The color mixture determination print output means 248 generates data of the color mixture determination pattern 80 as shown in FIGS. 16 and 17, or calls the data from the predetermined memory and sends the data of the color mixture determination pattern 80 through the head driver 236 to the print head 212Y, It is sent to 212C, 212M, and 212K, and output as a color mixture determination print.

  In this way, the operator visually determines the color mixture using the color mixture determination pattern output as the color mixture determination print, extracts the patch with the least color mixture and the highest resolution for each combination of the two colors, and sets the patch number. Input from the parameter setting means 246. Thereby, the best parameters of the conveyance speed (discharge time difference) V and the fixing energy E can be set for the combination of the recording paper 216 and the ink.

As described above, by selecting a combination of the fixing energy E and the conveyance speed V with the least color mixing and the highest resolution, the inter-nozzle row distances S (S _CY , S _MC or S _KM ) corresponding to the combinations of the two colors and the above-mentioned It is possible to satisfy S / V> t1 with respect to the fixing time t1 corresponding to the fixing energy E, and image recording that avoids color mixing is performed by performing image recording by performing control according to the parameters set in this way. Realized.

  Hereinafter, the operation of the present embodiment will be described with reference to the flowchart of FIG.

  First, in step S200 of FIG. 18, a magazine 222 for supplying the recording paper 216 to the inkjet recording apparatus 210 is loaded. In the next step S210, a color mixture determination print is output. In the mixed color determination print, the mixed color determination print output unit 248 generates data of the mixed color determination pattern 80 as shown in FIG. 16 and outputs it from the print heads 212Y, 212C, 212M, and 212K via the head driver 236.

  Next, in step S220, the operator visually determines the color mixture of each ink from the output color mixture determination print. Then, for each combination of the two colors, a patch based on a combination of the conveyance speed V and the fixing energy E with the least color mixing and high resolution is extracted.

  In the next step S230, the operator selects a patch number as shown in FIG. 16 for the patch extracted above, and inputs the number from the color mixture determination result input means such as a keyboard (not shown). The parameter setting means 246 holds control parameters for the distance S between nozzle rows corresponding to the number of each patch, the relative conveyance speed V, and the fixing time t1 (fixing energy). Each control parameter corresponding to the input number is set in each control means. In step S240, printing is executed with the set parameters.

  As described above, in the present embodiment, since the operator performs the color mixture determination visually using the color mixture determination pattern based on the resolution chart as shown in FIG. 17, the control parameter that can reliably avoid the color mixture is provided. Once the color mixture determination is performed and parameters are set, image recording that avoids the occurrence of color mixture can be executed at a high speed.

  In this embodiment, the print heads 212Y, 212C, 212M, and 212K are arranged as shown in FIG. 14, but this arrangement uses ink that is slow to penetrate and dry and has a long fixing time. It is preferable to dispose the head that is used or the head that uses ink with a large amount of curing energy on the upstream side in the transport direction. By arranging the print heads 212Y, 212C, 212M, and 212K in this way, the ink ejected from the print heads 212Y, 212C, 212M, and 212K onto the recording paper 216 is the next (downstream) print head 212Y, When reaching 212C, 212M, and 212K, the dried or cured state can be made uniform, and color mixing can be avoided efficiently.

  As described above, when the curing control unit 243 controls the curing energy of the curing unit 221 to control the curing time t2, at least the curing energy E, the conveyance speed V, and the inter-nozzle row distance S are set. One may be controlled so that S / V> t2 is satisfied and color mixing is avoided.

  In each of the embodiments described above, the nozzle group is constituted by each print head or each nozzle row divided by ink color, and the ink discharge time difference between each print head or each nozzle row is between each print head or each nozzle row. By controlling to be longer than the ink absorption time, it has become possible to prevent ink color mixing on the surface of the recording medium.

  Further, as a specific control method for making this difference in ejection time longer than the ink absorption time, the distance between the print heads (between nozzle rows) is such that the conveyance time between the recording media is equal to or longer than the ink absorption time. A method of arranging each print head (each nozzle row), applying fixing energy so that the ink is fixed within the conveyance time of the recording medium between each print head (between each nozzle row), or UV ink, solid ink A method of applying curing energy for curing the curable ink, and the like, and setting the relative conveyance speed of the recording medium according to the ink absorption time and the ink curing time of the recording medium between the print heads (between the nozzle rows) These methods can prevent color mixing of ink on the surface of the recording medium and enable high-speed recording. That.

  As described above, the color mixing determination method and the image recording method and apparatus of the present invention have been described in detail. However, the present invention is not limited to the above examples, and various improvements and modifications can be made without departing from the gist of the present invention. Of course you can go.

1 is a schematic configuration diagram including a partial block diagram illustrating an outline of an ink jet recording apparatus as an image recording apparatus according to a first embodiment of the present invention. It is a top view which expands and shows the printing head vicinity of the inkjet recording device of FIG. 1 is a block diagram illustrating a system configuration of an ink jet recording apparatus according to a first embodiment. It is explanatory drawing which shows the example of the color mixing determination pattern used in 1st Embodiment. (A) is explanatory drawing which shows each patch of the pattern for color mixture determination, (b) is explanatory drawing which expands and shows the boundary part. (A), (b) is sectional drawing which shows the mode of color mixing on the recording medium of two inks. (A), (b) is explanatory drawing which shows the principle of a density | concentration measurement. It is a diagram showing a density profile obtained by measuring each patch of the color mixture determination pattern with a densitometer. It is explanatory drawing which shows the method of determining mixed colors by density measurement. It is a flowchart which shows the effect | action of 1st Embodiment. It is explanatory drawing which shows each parameter for color mixture avoidance control. It is explanatory drawing which shows the relationship between image quality mode and a weighting coefficient. It is a block diagram including the partial top view which shows the outline of the inkjet recording device which concerns on 2nd Embodiment of this invention. It is a schematic block diagram including a partial block diagram which shows the outline of the inkjet recording device which concerns on 3rd Embodiment of this invention. It is a block diagram which shows the system configuration | structure of the inkjet recording device of 3rd Embodiment. It is explanatory drawing which shows the example of the color mixing determination pattern used in 3rd Embodiment. It is explanatory drawing which expands and shows one patch of the color mixing determination pattern of FIG. It is a flowchart which shows the effect | action of 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device (image recording device), 12Y, 12C, 12M, 12K ... Print head, 14 ... Paper feed unit, 16 ... Recording paper, 18 ... Conveying unit, 20 ... Fixing / curing means, 22 ... Magazine, 22a ... Media type detection notch, 24 ... Cutter, 25 ... Medium type detection means, 26, 27 ... Roller, 28 ... Ink type detection means, 29 ... Belt, 30 ... Suction chamber, 32 ... Fan, 34 ... Motor, 35 ... Color mixing Determining device 36 ... head driver 38 ... head distance control means 40 ... conveyance control means 41 ... encoder 42 ... fixing control means 43 ... curing control means 44 ... frequency control means 45 ... densitometer 46 ... parameter setting means, 48 ... mixed color determination print output means, 49 ... mixed color determination means, 51 ... average value / standard deviation calculation means, 53 ... recording mode detection means, 138 238 ... nozzle row separation distance control means

Claims (11)

A droplet is ejected from a first print head having a nozzle row for discharging ink of the first color toward a recording medium, and the first print head and the recording medium are moved relative to each other, thereby recording the recording medium. A step of printing a rectangular first color region in which a plurality of dot rows of ink dots of the first color are aligned and integrated in the relative movement direction;
Performing droplet ejection from a second print head having a nozzle row that ejects ink of a second color different from the first color onto a range where the first color region on the recording medium partially overlaps and is adjacent to the first color region; By moving the second print head and the recording medium relative to each other, a plurality of dot rows of the second color ink dots are arranged in the relative movement direction, and the dot rows of the second color ink dots are changed. And a step of printing a rectangular second color area partially overlapping with the first color area, and a color mixture determination in which the first color area and the second color area partially overlap each other Forming a patch for
The first color for a plurality of locations including overlapping portions of the first color region and the second color region in the color mixture determination patch along a direction in which the first color region and the second color region are adjacent to each other. And the step of measuring the density of each color of the second color with a densitometer and obtaining the density profile of each color in the adjacent direction by the density measurement, a plurality of directions orthogonal to the adjacent direction with respect to the patch for color mixture determination To obtain a plurality of sets of density profiles for two colors corresponding to the plurality of positions, obtain distances between density points that are respectively predetermined threshold values from the density profiles of the two colors of each set, and Calculate at least one of the average value and standard deviation of the distance,
A color mixing determination method, wherein a color mixing state of two colors in the overlapping portion is determined based on at least one of the calculated average value and standard deviation. The ejection time difference between the timing at which the first color ink dots start to be ejected and the timing at which the second color ink dots begin to be ejected at the overlapping portion, and the relative conveyance of the recording medium with respect to the first and second print heads A plurality of color mixing judgments by changing at least one of speed, fixing energy for fixing ink dots on the recording medium to the recording medium, and curing energy for curing ink on the recording medium in a plurality of steps. A patch is formed on the same recording medium,
2. The color mixing determination method according to claim 1, wherein for each color mixing determination patch on the color mixing determination print having the plurality of color mixing determination patches, the color mixing state of the overlapping portion is determined based on the density profile. .   An evaluation value used for determination of color mixture is calculated according to each of the average value of the distance, the standard deviation, the discharge time difference, and the recording mode indicating whether the recording medium is text, image, or both. 3. The color mixing determination method according to claim 2, wherein the color mixing state is determined by calculating the evaluation value by weighting an element for the purpose. A control parameter for controlling at least one of the discharge time difference, the relative conveyance speed, the fixing energy, and the curing energy is set based on a color mixing determination result obtained by the color mixing determination method according to claim 2. And
An image recording method for recording an image on the recording medium based on the setting.   5. The image recording method according to claim 4, further comprising: a type of the ink, a type of the recording medium, and a recording mode that indicates whether an object to be recorded on the recording medium is text, image, or both. An image recording method characterized in that the control parameter is set accordingly. A droplet is ejected from a first print head having a nozzle row for discharging ink of the first color toward a recording medium, and the first print head and the recording medium are moved relative to each other, thereby recording the recording medium. On the other hand, a control is performed to print a rectangular first color region in which a plurality of dot rows of ink dots of the first color are aligned and integrated in the relative movement direction.
Performing droplet ejection from a second print head having a nozzle row that ejects ink of a second color different from the first color onto a range where the first color region on the recording medium partially overlaps and is adjacent to the first color region; By moving the second print head and the recording medium relative to each other, a plurality of dot rows of the second color ink dots are arranged in the relative movement direction, and the dot rows of the second color ink dots are changed. A mixed color in which the first color area and the second color area partially overlap each other by performing control to print a rectangular second color area that partially overlaps the first color area. A color mixture determination print output means for forming a determination patch;
The first color for a plurality of locations including overlapping portions of the first color region and the second color region in the color mixture determination patch along a direction in which the first color region and the second color region are adjacent to each other. Density measuring means for measuring the density of each color of the second color and obtaining a density profile of each color in the adjacent direction by the density measurement;
The density measurement is performed at a plurality of positions in a direction orthogonal to the adjacent direction with respect to the color mixture determination patch, and density profiles for a plurality of sets of two colors corresponding to the plurality of positions are obtained. The distance between the concentration points serving as a predetermined threshold is determined from the concentration profile of each minute, and at least one of the average value and the standard deviation of the distance is calculated. Based on at least one of the calculated average value and standard deviation Color mixture determination means for determining a color mixture state of two colors in the overlapping portion;
A color mixing determination device comprising: The mixed color determination print output means is configured to output a difference in discharge time between a timing at which the first color ink dots start to be discharged and a timing at which the second color ink dots start to be discharged at the overlapping portion, and the first and second prints. A plurality of steps with at least one of parameters of a relative conveyance speed of the recording medium with respect to the head, a fixing energy for fixing the ink dots on the recording medium to the recording medium, and a curing energy for curing the ink on the recording medium. 7. The color mixing determination apparatus according to claim 6, wherein a plurality of color mixing determination patches are formed on the same recording medium, and a color mixing determination print having the plurality of color mixing determination patches is output.   The color mixing determination means determines color mixing according to each of an average value of the distance, a standard deviation, a difference in the ejection time, and a recording mode indicating whether a recording medium is text, image, or both. The color mixing determination apparatus according to claim 7, wherein the color mixing state is determined by weighting an element for calculating an evaluation value to be used and calculating the evaluation value. A first print head having a nozzle row for ejecting a first color ink; a second print head having a nozzle row for ejecting a second color ink different from the first color; and the first and second An image recording apparatus for recording an image by ejecting dots onto the recording medium.
While having the color mixing determination apparatus of any one of Claims 6 thru | or 8,
A discharge time difference control means for controlling a discharge time difference of dots by the first and second print heads;
Fixing means for fixing dots ejected onto the recording medium;
Fixing control means for controlling the fixing energy of the fixing means;
Curing means for curing the dots deposited on the recording medium;
Curing control means for controlling the curing energy of the curing means;
Parameter setting means for setting a control parameter for controlling at least one of the ejection time difference control means, the fixing control means, and the curing control means, based on a color mixture determination result by the color mixture determination apparatus;
And an image recording apparatus for performing image recording according to the control parameter set by the parameter setting means. A first print head having a nozzle row for discharging the first color ink;
A second print head having a nozzle row that ejects ink of a second color different from the first color; means for moving the recording medium relative to the first and second print heads;
While performing droplet ejection from the first print head toward the recording medium, by moving the first print head and the recording medium relative to each other, a dot row of ink dots of the first color is formed on the recording medium. Is controlled to print a rectangular first color region integrated in a plurality of rows in the relative movement direction, while the first color region and a part of the first color region on the recording medium from the second print head. While performing droplet ejection in an overlapping and adjacent range, and by relatively moving the second print head and the recording medium, a plurality of dot rows of the second color ink dots are arranged in the relative movement direction, In addition, by performing a control to print a rectangular second color region in which a part of a dot row of the ink dots of the second color overlaps and is integrated with the first color region, the first color region and the first color region Second color And color mixing evaluation print output means and the band to form a patch for color mixing determination overlapped partially,
A discharge time difference control means for controlling a discharge time difference between a timing at which the first print head starts to discharge dots and a timing at which the second print head starts to discharge dots when recording the recording data on the recording medium; ,
Fixing means for fixing dots ejected onto the recording medium;
Fixing control means for controlling the fixing energy of the fixing means;
Curing means for curing the dots deposited on the recording medium;
Curing control means for controlling the curing energy of the curing means;
A color mixture determination result input means for inputting a color mixture determination result of two color dots based on the color mixture determination patch;
Parameter setting means for setting a control parameter for controlling at least one of the ejection time difference control means, the fixing control means, and the curing control means based on the color mixture judgment result input to the color mixture judgment result input means; ,
An image recording apparatus characterized in that image recording is performed according to the control parameter set by the parameter setting means.   11. The image recording apparatus according to claim 9, further comprising: an ink type detecting unit that detects an ink type; a recording medium type detecting unit that detects the type of the recording medium; Comprising recording mode detecting means for detecting a recording mode indicating whether the image is text or image or both, and means for setting and storing the control parameter in accordance with the ink type, the recording medium type and the recording mode. An image recording apparatus.

Images