JP2006168372A - Inkjet recording method and inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording method for recording a high-quality image on an optically-transparent recording medium having an ink receiving layer, and an apparatus therefor. <P>SOLUTION: In the apparatus which can use a black ink containing a black pigment and color inks containing colorant of at least cyan, magenta, and yellow, the image including a black area is recorded by using the black ink and the color inks in combination with respect to optical transparency having the ink receiving layer. Herein, 30% or more and 70% or less of the area of the black area showing the highest density is recorded with the black ink, and the black area except for that is recorded with the color inks. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inkjet recording method, an inkjet recording apparatus, and a computer-readable storage medium for recording a color image or a monochrome image using at least one of a pigment ink and a dye ink.

  Inkjet recording methods include electrostatic attraction by applying a high voltage, a method of applying mechanical vibration or displacement to ink (colored ink) using a piezoelectric element, a method of using pressure that causes ink to foam when heated, etc. Ink droplets are generated by various ink ejection methods, and the droplets are ejected and attached to a recording medium such as paper to form ink dots for recording. The use of a highly integrated head has the advantage that a high-resolution recorded image can be obtained at high speed.

  As an ink used in such an ink jet recording method, a dye-based ink in which various water-soluble dyes are dissolved in water or a mixed liquid of water and an organic solvent has been used. However, fastness such as light resistance and water resistance has often been a problem for recorded images using dye-based inks. In particular, black color, which is often used for official documents, is required to be particularly robust compared to other colors.

  On the other hand, a pigment ink in which a pigment dispersion in which a pigment is dispersed in a polymer dispersant is dissolved in a water-soluble solvent is disclosed in JP-A Nos. 56-147859 and 56-147860. Since pigment ink has characteristics superior to dye ink in terms of water resistance and light resistance, various pigment inks have been studied. Recently, the use of pigment inks has particularly improved the printing quality of characters and lines. Inkjet printers are also known.

  The reason why the printing quality is improved by using pigment ink is briefly described. Because pigment particles are larger than dyes, pigments are difficult to penetrate into the back of fibers such as plain paper, and are stagnated near the surface. This is because the printed density is high and the permeation to the surroundings is small, so that the boundary is clearly and clearly printed.

  However, at present, pigment inks other than black are difficult to realize in terms of color developability, and many ink jet printers that employ pigment ink use pigment ink only for black ink, and color ink (generally cyan ink). , Magenta and yellow) use dye ink.

  Currently, inkjet printers include inkjet recording paper, postcards, cloth, glossy paper, plastic glossy films, transparent sheets used for projection by projectors (hereinafter referred to as OHP sheets), as well as plain paper. A back print film having an ink receiving layer on one side of a substrate and observed from the opposite side of the surface on which the ink receiving layer is provided, and a transfer medium used for transferring the recorded surface to a cloth or a plate Etc., and can be applied to various uses. Among these, ink-jet exclusive paper, glossy paper, glossy film, OHP sheet, back print film, and transfer medium are generally provided with an ink receiving layer for absorbing ink on a substrate.

  In the case of dye-based inks, the dye develops color when dyed on the recording medium, so the surface condition of the recording medium has little effect on the image density, but in the case of pigment ink, the pigment is the surface of the recording medium. Since it aggregates and adheres in the vicinity, the influence of the surface state of the recording medium on the image density is great. In addition, pigment ink tends to have a rough recording surface after fixing due to its large color former particles as described above due to its characteristics.

  Therefore, the pigment ink has a disadvantage that the image density is remarkably deteriorated and the image quality is deteriorated depending on the type of the recording medium.

  For example, it is good to record on a recording medium with a rough surface such as plain paper, but when recording on a glossy special medium such as glossy paper or glossy film, the original glossiness of the medium is lost, so-called photographic image quality. Is not preferable. In particular, when recording is performed simultaneously with dye color ink, a non-glossy portion is locally scattered in a dark portion or the like of the image, resulting in a very uncomfortable image. This problem occurs to a lesser extent not only in glossy media but also in so-called coated paper having an ink-receiving layer on a substrate, such as non-glossy inkjet paper. This is presumably because the roughness of the pigment ink particles is conspicuous because the ink receiving layer smoothes the unevenness of the paper surface, but not as much as the glossy medium.

  In the case of a recording medium (back print film or the like) having an ink receiving layer on one side of the base material as described above and observed from the opposite side of the surface on which the ink receiving layer is provided, a pigment ink is used. Even if recorded, the image is difficult to see and sufficient print density cannot be obtained. This is because the pigment ink does not enter the ink receiving layer so much and stays near the surface, so that the pigment ink hardly penetrates to the opposite side of the recorded surface.

  In addition, when recording on a plastic sheet provided with an ink receiving layer using pigment ink, the recording surface after fixing may crack depending on the type of pigment, the composition of the ink, and the material and structure of the ink receiving layer. May end up. In particular, since the OHP sheet is enlarged and projected by an overhead projector, this crack can be clearly perceived. Such cracks degrade the image quality.

  The cause of the occurrence of cracks will be briefly described below. Generally, an ink receiving layer on the surface of an OHP sheet for an ink jet printer has a mechanism for absorbing ink by swelling. On the other hand, the pigment ink has large color former particles as described above due to its characteristics, so that it is not absorbed so much by the ink receiving layer and stays on the surface of the receiving layer. Then, the pigments are bonded to each other on the surface to form a layer and are dried as it is. It is considered that cracks occur when the ink receiving layer swollen by sucking the ink solvent into the layer is pushed up.

  Further, since the pigment ink is fixed near the surface of the medium, the scratch resistance is inferior to that of the dye ink, and is easily removed when rubbed. For double-sided recording such as postcards, one side is recorded and then loaded on the auto sheet feeder to record the opposite side. At this time, the pigment ink recorded on the backside of the postcard is May stick to other paper.

  In order to solve the above problems, an object of the present invention is to provide a method and an apparatus for recording a high-quality image on a light-transmitting recording medium having an ink receiving layer. It is another object of the present invention to provide a method and apparatus for recording high-quality images on various types of recording media.

  It is another object of the present invention to provide a method and apparatus for recording an image having sufficient print density and excellent fastness by utilizing the characteristics of pigment ink.

  To achieve the above object, the present invention provides an ink jet recording method for recording an image using at least one of black ink containing a black pigment and each color ink containing at least cyan, magenta and yellow dyes. And a step of recording an image including a black region by using the black ink and the color ink in combination on a light-transmitting recording medium having an ink receiving layer, wherein the black region exhibiting the highest density in the recording step 30% to less than 70% of the area is recorded with the black ink, and the black region that is not recorded with the black ink is recorded with the color ink.

  The present invention also relates to an ink jet recording method for recording an image using at least one of a black ink containing a black pigment and each color ink containing at least cyan, magenta and yellow dyes. In the case of recording a black image on a light-transmitting recording medium having, an ink jet recording method characterized in that a region showing the highest density in the black image is recorded with both the black ink and the color ink. An area showing the highest density in the black image is recorded.

  The present invention is also an ink jet recording method using a recording apparatus capable of recording an image on a recording medium using a black ink containing a black pigment and each color ink containing at least cyan, magenta, and yellow dyes. A step of determining the type of ink to be used based on at least a signal indicating the type of recording medium and the type of recording mode, and a step of recording on the recording medium using the determined ink. In the determining step, when the signal indicating the type of the recording medium is a signal indicating a light-transmitting recording medium having an ink receiving layer and the signal indicating the type of the recording mode is a signal indicating a monochrome mode, Light that determines the use of the black ink and the color ink to record the highest density area of a black image, and the signal indicating the type of the recording medium has an ink receiving layer When the signal indicating the transient recording medium and the signal indicating the type of the recording mode is a signal indicating the color mode, the use of the color ink and the black ink is determined for recording the highest density area of the black image. It is characterized by.

  Further, the present invention scans a discharge medium that discharges black ink containing a black pigment and each discharge section that discharges each color ink containing at least cyan, magenta, and yellow dyes relative to the recording medium. However, an inkjet recording apparatus for recording an image on the recording medium, wherein the black ink and the color ink are used together to record an image including a black region on a light-transmitting recording medium having an ink receiving layer. 30% or more and less than 70% of the area of the black region showing the highest density is recorded with the black ink, and a black region not recorded with the black ink is recorded with the color ink.

  Further, the present invention scans a discharge medium that discharges black ink containing a black pigment and each discharge section that discharges each color ink containing at least cyan, magenta, and yellow dyes relative to the recording medium. However, when the recording medium is an ink-jet recording apparatus that records an image on the recording medium, and the recording medium type is a light-transmitting recording medium having an ink receiving layer and the recording mode type is a monochrome mode, a black image When the color ink and the black ink are used in combination, the recording medium type is a light-transmitting recording medium having an ink receiving layer, and the recording mode type is a color mode. , And recording the highest density region of the black image by using the color ink and the black ink together.

  As described above, according to the present invention, since the type of ink to be used is selected according to the type of recording medium and the printing mode, it is possible to record a high-quality image utilizing the characteristics of the ink. It becomes possible.

  Further, by utilizing the characteristics of the pigment ink, it is possible to record an image having a sufficient printing density, forming a sharp edge, and having excellent fastness.

  Furthermore, the density of the black region can be increased by mixing the pigment ink and the dye ink at a predetermined ratio to form a black region.

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

<Example Embodiment>
FIG. 1 shows an example of an embodiment of an ink jet recording apparatus to which the present invention is applied. In FIG. 1, a plurality (four) of head cartridges (recording means) 1 </ b> A, 1 </ b> C, 1 </ b> C, and 1 </ b> D are mounted on the ink jet printer 13 in a replaceable manner. In addition, when referring to the whole or any one of the plurality of recording units 1A to 1D, the recording unit (recording head or head cartridge) 1 is simply indicated.

  Each head cartridge 1 has an ink tank portion at the upper portion and a recording head portion (ink discharge portion) at the lower portion, and has a structure in which the recording head and the ink tank are integrated. Each recording means 1 is mounted on the carriage 2 in a replaceable manner, and each recording means 1 is provided with a connector (not shown) for receiving a signal for driving the recording head portion. ing. On the other hand, the carriage 2 is provided with a connector holder (electric connection portion) for transmitting a drive signal and the like to each recording means 1 through the connector. Each recording means 1 on the carriage 2 and the control circuit on the apparatus main body side are connected by a flexible cable for flowing a signal pulse current and a temperature adjusting current.

  Each head cartridge contains black (K) pigment ink 1A and cyan (C), magenta (M), and yellow (Y) dye inks 1B, 1C, and 1D, respectively, in the upper ink tank. A plurality of ejection openings for ejecting ink have a predetermined print resolution (for example, 360 dpi, dpi is dot per inch, the number of dots per inch) on the surface of each recording head portion facing the recording medium 8. It is formed in rows with corresponding intervals (for example, about 71 μm in the case of the above-mentioned 360 dpi), and each of the stored ink is ejected. Here, the number of discharge ports for K is larger than the number of other CMY three-color discharge ports. When recording monochrome images such as black characters and black lines that are generally used for many purposes, only the discharge port for K is used. By using it, it is possible to record at high speed. Hereinafter, three colors of cyan, magenta, and yellow are represented by CMY, and four colors including black are represented by CMYK.

  The carriage 2 is guided and supported so as to reciprocate along a guide shaft 3 installed in the apparatus main body so as to extend in the main scanning direction. The carriage 2 is driven by a main scanning motor 4 via a motor pulley 5, a driven pulley 6, and a timing belt 7, and its position and movement are controlled. A recording medium 8 such as a sheet or a plastic thin plate is sandwiched between two pairs of transport rollers 9, 10 and 11, 12, and is opposed to the discharge port surface of the recording head 1 by the rotation of the transport rollers (recording). Part) is conveyed (paper feed). Note that the back surface of the recording medium 8 is supported by a platen (not shown) so as to form a flat recording surface in the recording unit. In this case, the head cartridges 1 mounted on the carriage 2 are held so that their discharge port surfaces protrude downward from the carriage 2 and are parallel to the recording medium 8 between the two pairs of transport rollers. Yes.

  The ink jet printer 13 configured integrally with these is connected to a personal computer 14 via a cable 15 and controlled by driver software installed in the personal computer 14.

  FIG. 2 is an example of a property setting screen of the ink jet printer 13 in the user interface of the driver software. By specifying a recording medium to be recorded by the inkjet printer 13 from a pull-down menu displayed with “paper type” 16, R (red), G (green), and B (blue) to be recorded are specified. The image data is converted into CMYK recording data that is optimal for the type of each recording medium. When the check box of “Grayscale printing” 17 is checked, the RGB values of the image data to be recorded are converted into monochrome data based on a predetermined method, for example, X = (2 * R + 2 * G + B) / 5. The converted data is sent via the cable 15 so that the inkjet printer 13 records the image data of only one hue of the gray color. In this specification, the color mode is a mode for recording a color image of a plurality of colors, and the gray scale mode is a mode for recording a monochrome image. In general, when the RGB signal values are each represented by 8 bits, when the input image data is R = G = B = 255, complete white is recorded, and when R = G = B = 0, complete black is recorded. To be recorded. In the present specification, the highest density black (black solid) to be recorded is black recorded when the RGB value of the input image data is R = G = B = 0. When the input image data of a pixel is R = G = B = 0, the pixel is recorded with the highest density black.

  FIG. 3 is a diagram showing which ink is used for recording according to the type of recording medium. Below, the reason which becomes as shown in FIG. 3 is demonstrated.

  First, when the set recording medium is glossy (glossy paper, glossy film, etc.), if it is in the color mode, recording is performed with three colors of CMY ink. That is, the black portion is generated by so-called composite black formed by overlapping CMY. The reason for this is that, as described above, when the black pigment ink and the color ink of the dye are recorded simultaneously, only the portion where the pigment ink is applied becomes a non-glossy part, and the non-glossy part is locally scattered, which is very uncomfortable. This is because such an image is not preferable in terms of photographic quality. In other words, since the pigment has a large particle size, it cannot penetrate into the medium, and remains on the medium surface and covers the glossy part of the medium surface, so that only the surface part where the pigment remains is lost. . On the other hand, since the dye has a small particle diameter, the dye penetrates into the inside of the medium, so that the influence on the medium surface is very small compared to the pigment.

  In the gray scale mode, recording is performed with one black color (pigment ink). This is considered that when the user dares to select the gray scale mode, he / she often wants to record black characters, black lines, etc. rather than recording a color image in gray scale. In such a case, the area of the black portion is generally not so large and is not a photographic image. Therefore, even if the black pigment ink is recorded and the glossiness of the portion is lost, there is no problem in image quality. Conversely, black due to composite black is generally lighter than the black density of the pigment black ink, and if the position adjustment between the colors of the head is insufficient, the color protrudes around black characters and black lines. In the case of small font characters and thin lines, and the image to be recorded is not the highest density black (100% black, that is, the RGB value of the input image data is R = G = B = 0), the color is changed. There is also a tendency that bad characters such as thin letters and thin lines occur. Therefore, it is desirable to record with only one color of pigment black ink in the gray scale mode.

  Further, even in a non-glossy medium in which an ink receiving layer is provided on a base material, such as ink jet dedicated paper, as in the case of the above-described glossy medium, recording is performed with three colors of CMY inks in the color mode. In the gray scale mode, recording is performed with one color of black pigment ink. This is because the non-glossy medium also has an ink-receiving layer, and only the pigment remains on the surface of the medium in the same manner as described above. is there. That is, the surface of the non-glossy medium is smoothed by the ink receiving layer, and recording is performed using both the pigment black ink and the dye color ink on the smoothed surface. This is because only the pigment particles are conspicuous because only the pigment remains on the medium surface, which is not preferable as an image. On the other hand, the dye particles do not stand out because they penetrate into the medium. This phenomenon is considered to be particularly prominent when the surface irregularities are smoothed. That is, a recording medium such as plain paper that does not have an ink-receiving layer on the surface of the medium has a smooth surface and has larger surface irregularities than the non-glossy medium or the glossy medium, so that the pigment is injected. However, the roughness of the pigment particles is not so noticeable because the surface is originally rough, but when pigment particles with a large particle diameter are driven into the surface of the medium with few surface irregularities, the particle diameter is larger than the irregularities on the surface, so the roughness of the pigment particles Will stand out. While the plain paper fiber itself is 1 to several tens of μm, the particle diameter of silica, alumina, etc. constituting the ink receiving layer of the glossy medium and non-glossy medium is 0.01 to 0. .1 μm. The size of the pigment particles is about 1 μm in an aggregated state. From these, it can be seen that since the pigment particles are larger than the particle system constituting the surface, the roughness of the particles becomes conspicuous. It can also be seen that it cannot penetrate into the ink receiving layer.

  In the gray scale mode, it is desirable to record with only one pigment black ink for the same reason as in the case of the glossy medium.

  The substrate constituting the glossy medium and the non-glossy medium is an opaque substrate such as paper or film.

  Further, when the image data has a single gray hue such as R = G = B, the user may automatically switch to the grayscale mode without selecting the grayscale mode.

  Next, a case where the recording medium has an ink receiving layer on one side of a substrate such as a back print film or a T-shirt transfer medium, and is a recording medium observed from the side opposite to the side where the ink receiving layer is provided. explain. When the recording medium is a medium observed from the opposite side of the recorded surface, the pigment ink hardly penetrates to the opposite side of the recorded surface as described above, so that it is difficult to see the image even when recording with the pigment ink. A sufficient print density cannot be obtained. For this reason, a dye ink that easily penetrates into the ink receiving layer is used. For this reason, recording is performed in three colors of CMY in both the color mode and the gray scale mode.

  Next, the case where the recording medium is a light-transmitting recording medium provided with an ink receiving layer will be described. In the following, a plastic sheet is taken as an example of a light transmissive recording medium, but the present invention is not limited to this.

  When the recording medium is a plastic sheet provided with an ink receiving layer, recording is performed in four colors of CMYK in both the color mode and the gray scale mode. When recording the black area, the black pigment ink and the dye color ink are ejected onto the recording medium at a predetermined ratio. That is, black by pigment ink and black by composite black are mixed on the recording medium to form a black region (FIG. 7B). The reason for this is that the density of the black part is higher when the black region is formed by ejecting the pigment black ink and the dye color ink onto the recording medium at a predetermined ratio than when recording only with the pigment black ink, This is because there is an effect of increasing the concentration. In addition, since the black region is formed by using the pigment black ink and the dye color ink in combination, the amount of the pigment black ink to be used can be reduced, so that cracking is less likely to occur. FIG. 7B is a diagram in which a black region is formed by using a pigment black ink and a dye color ink in combination, and FIG. 7A is a diagram in which a black region is formed when recording is performed using only the pigment black ink. FIG.

  Here, Table 1 shows experimental results of the degree of cracking with respect to the amount of pigment black ink applied. As can be seen from this, the cracking problem does not occur if the amount of pigment black ink applied is approximately 80% or less. The definition of the amount of ink shot will be described later.

  FIG. 4 is a contour line showing the black density when a black region is formed by discharging pigment black ink and dye color ink onto a plastic sheet provided with an ink receiving layer. The horizontal axis represents the total amount of the three color inks applied, and the vertical axis represents the black ink amount. In this specification, in the case where each ink (C, M, Y, K) is applied to a predetermined unit area (one pixel) on plain paper, The minimum ink amount required to fill the predetermined unit area (one pixel) with each of the inks is defined as “printing amount 100%”. Therefore, the hit amount X% is a ratio with respect to the hit amount of 100%. That is, when the ink amount required for the hit amount of 100% is 1, the ink amount required for the hit amount of 80% is approximately 0. 8. Further, when ink is applied to one pixel with an ink amount of 80%, that is, an ink amount of 0.8, approximately 80% in one pixel is filled with ink. ")" Can also be referred to as "the ratio of the area filled with each ink out of the predetermined area of one pixel". For example, the pigment black ink ejection amount of 70% in Table 1 refers to the amount of pigment black ink deposited when the ejection amount is 100% as a reference value, and an ink amount of approximately 70% of the reference value is one pixel. In other words, it can be said that the ratio of the area filled with the pigment black ink out of the predetermined area of one pixel is 70%. In general, the ink receiving layer has a larger allowable amount of ink to be ejected than plain paper, so that no ink overflow occurs even if the amount of ink to be ejected greatly exceeds 100%. Specifically, the upper limit of the ink ejection amount for the ink receiving layer is approximately 300%, that is, approximately 3 times the minimum ink amount necessary to fill one pixel on plain paper. Is possible.

  It can be determined by examining the recorded medium surface what percentage of the black area is formed by the pigment ink. It can also be understood by examining the amount of image data of pigment black ink among the image data to be recorded in the black area.

  In the present invention, the density means an optical density (optical density). Moreover, in order to measure a density | concentration, it can measure using density | concentration measuring device Model404A (made by X-Rite), for example.

  FIG. 5 is a diagram showing a black density when a pigment black ink is singly applied to a plastic sheet provided with an ink receiving layer, and FIG. 6 is a method of driving dye color ink onto a plastic sheet provided with an ink receiving layer. It is a figure which shows the black density by the composite black formed with the dye color ink which plunged in, and both have the upward convex characteristic. This is a general behavior of an ink jet printer. Note that the color ink placement amount shown on the horizontal axis in FIG. 6 is the total placement amount when the CMY dye color inks are respectively ejected.

  The concentration increasing effect described above can be seen from FIGS.

  First, as can be seen from FIG. 5, the maximum value of the black density when recording with only the pigment black ink is about 1.4. Further, as can be seen from FIG. 4, the line in which the total amount of pigment black ink and dye color ink is 300%, which is the upper limit of the general ink ejection amount of the plastic sheet provided with the ink receiving layer (in the figure). In the vicinity of A), it can be seen that the maximum density can be obtained when the amount of pigment black ink is about 50% and the amount of dye color ink is about 250%. The density value is approximately 1.7.

  As described above, the density of the black portion is higher when the black area is formed by discharging the pigment black ink and the dye color ink onto the recording medium at a predetermined ratio than when recording only with the pigment black ink. You can see that there is a rising effect.

  Here, the reason why the density line in FIG. 4 has such a shape will be described.

  The black density when the black region is formed by using the pigment black ink and the dye color ink together is represented by the following formula.

Formula: [Black Density] = [Black Density Corresponding to Black Ink Amount] + [Area Ratio Value of Black Ink Not Placed (Black Ink Gap)] × [Color Ink Amount Corresponding (Black density by composite black)
For example, assume that the amount of black ink applied is 50% and the amount of color ink applied is 180%. First, since the amount of black ink applied is 50%, it can be seen from FIG. 5 that the black density is approximately 1.2. Next, the area ratio value where the black ink is not applied is 0.5. This is because 50% of black ink is applied per unit area, and the area where black ink is not applied corresponds to the remaining 50%. Finally, the black density of the composite black corresponding to the amount of color ink applied is 180% because the amount of color ink applied is 180%, and it can be seen from FIG. 6 that the black density is about 0.8. When the above numerical values are applied to the above formula, [black density] = [1.2] + [0.5] × [0.8] = [1.6]. This density value 1.6 substantially coincides with the density value in FIG.

  As described above, the black density in the case where the black region is formed by using the pigment black ink and the dye color ink together is expressed by the above formula, so the density line in FIG. 4 has such a shape. .

  From the above, it can be seen that since the gap between the dots of the pigment black ink is generated when the amount of the pigment black ink is lowered from 100%, there is an effect of increasing the density by the color ink. Note that when the input image data is R = G = B = 0 and the maximum density black (solid black) is recorded, the amount of pigment black ink applied is preferably 30% to 70%, more preferably 40%. ~ 60%, optimally about 50%. If it exceeds 70%, cracks may occur, and if it is less than 30%, the black density becomes thin. Therefore, 30% to 70% is preferable when recording a black solid.

  Also, when the pigment black ink is at 100%, the black ink covers the surface of the receiving layer, so no matter how much color dye ink is applied, it is only absorbed by the receiving layer and does not come out on the surface. do not do. That is, if the amount of pigment black ink is set to 100%, the effect of increasing the density by further applying the dye color ink cannot be obtained.

  According to this result, the case of recording on the OHP sheet as a plastic sheet will be described. In the OHP sheet used in this embodiment, an ink receiving layer is provided on both sides of a base (base material) of a transparent plastic sheet in order to prevent erroneous front / back discrimination. The OHP sheet absorbs ink by swelling of the ink receiving layer on the surface of the OHP sheet.

  When recording on the OHP sheet as described above, first, the “OHP sheet” paper designation, the recording quality, and other recording conditions are designated on the user interface (not shown) of the driver software. In accordance with the specified conditions, the driver software converts the image data into CMYK dot data and transfers it.

  FIG. 8 shows a gray scale data of 256 gradations (0 to 225) expressed by 8 bits by the driver software (0 is completely white, 225 is completely black, that is, the highest recorded value in this embodiment. FIG. 6 is a diagram illustrating the ink ejection amount of CMYK dot data obtained by converting density black). However, FIG. 8 shows the amount of ink applied to the OHP sheet. The definition of 100% here is the same as described above.

  In FIG. 8, at the maximum density black (black solid) to be recorded, that is, at the gray scale level 225, the hit amount of black ink is about 50%, cyan ink is about 84%, magenta ink is about 95%, and yellow ink is about 71%. It is said. (The CMY total is 250%, and the ratio of the three colors is not necessarily the same because it depends on the dye density and color development characteristics of the ink.) This amount of black 50% is the above-mentioned amount when the pigment ink alone is recorded on the OHP sheet. This is an ink ejection amount at a level that does not cause cracks.

  In order to produce a clear gradation of the image, the dot ratio in the middle part of the gray scale is continuously changed as shown in FIG. 8 toward the dot ratio of black (solid black) of the highest density to be recorded. It is desirable to go. That is, the larger the gray scale level, the greater the amount of pigment black ink shot. In FIG. 8, for example, when recording a black region with a gray scale level of 208, the amount of pigment black ink applied is about 10%, and when recording a black region with a gray scale level of 224, The driving amount is about 25%. When the gray scale level is less than 176, recording is performed without using the pigment black ink. The pigment black ink is not limited to the driving amount as shown in FIG. 8, and it is sufficient that a smooth gradation can be formed. That is, in FIG. 8, the maximum amount of pigment black ink applied is 50%, but is not limited to this, and if it is 80% or less, the above-described cracks may not easily occur. In FIG. 8, when the gray scale level is lowered, the black region is formed without using the pigment black ink, but the pigment black ink may be used even at a low gray scale level.

  In this embodiment, the CMYK dot ratio as shown in FIG. 8 is generated by the driver software. However, as another embodiment of the present invention, a printer is used based on the K dot data transferred from the driver. The CMYK dot data may be generated from the data in accordance with the dot ratio. As described above, when the black pigment ink and the dye color ink are simultaneously ejected, the print density is increased, which is particularly effective for an OHP sheet that requires a high density. In the above-described embodiment, the case of recording on the OHP sheet has been described, but it is naturally applicable to other plastic sheets.

  Next, a case where the recording medium is a postcard will be described. When the recording medium is a postcard, the color mode is recorded in four colors CMYK. As in the case of the OHP sheet described above, when recording the black area, the black pigment ink and the dye color ink are ejected onto the medium at a predetermined ratio. As a countermeasure against the problem when the auto sheet feeder is used for postcard printing as described above, the pigment ink is prevented from adhering to the next paper by reducing the amount of pigment black ink applied. However, if the amount of pigment black ink applied is reduced, the print density decreases. Therefore, in order to compensate for this decrease in density, a composite black of color dye is used simultaneously with the pigment black ink. In addition, when forming a black area | region in a postcard, it is preferable to form 40% or more and less than 90% of the area of a black area using a pigment black ink, Preferably it is 50% or more and less than 70%. As can be seen from Table 2 below, if the amount is less than 40%, there is an adverse effect that the print density becomes unacceptably thin even if the color ink is overprinted. This is because the scratch resistance of the toner becomes worse (the fixing of the pigment worsens and adheres to the next paper).

  In the gray scale mode, recording is performed with one color of black pigment ink. In this case as well, as in the color mode described above, the amount of pigment black ink is reduced, but no dye color ink is used in combination. This is because in postcard grayscale mode, black characters such as addresses and addresses are often printed, and it seems that it is preferable to give priority to printing speed over image quality and scratching problems. . In this case, as can be seen from Table 2 below, it is desirable that the ratio of the pigment black ink is approximately 80% from the balance between the density and the scratch resistance. In addition, when recording with only one color of pigment black ink, printing can be performed using only the K ejection port without using the color ink ejection port, thereby enabling high-speed printing.

  In the above-described embodiment, the gray scale mode is recorded with one color of pigment black ink. However, when priority is given to image quality over speed, the gray scale mode is also similar to the color mode described above. In order to increase the print density, recording may be performed with four colors of CMYK. In any case, when recording on a postcard, it is preferable to record the image data by thinning the number of dots of the pigment black ink. By recording the thinned image data, the pigment ink is printed on the next paper. Adverse effects such as adhesion can be avoided, and there are effects such as an increase in printing speed. Table 2 below is a table showing whether the density of the black region is good and the scratch resistance is good when recording with a black pigment ink and a dye color ink on a postcard. When recording the black area in the color mode, refer to (3) and (4) of Table 2, and when recording the black area in the gray scale mode, refer to (2) and (4) of Table 2. Thus, it is possible to know the optimum amount of the black pigment ink.

  Finally, when the recording medium is other than the above such as plain paper, the color mode is recorded in four colors of CMYK. That is, when the ink receiving layer is not provided on the substrate and the recording medium is non-glossy, the surface of the recording medium is rough because the ink receiving layer is not provided as described above. Because it is a non-glossy recording medium, it does not change that the surface is not glossy even if the pigment ink is recorded. Rather, using the pigment black ink to increase the maximum density gives the image with high contrast. Will be expensive. In the case of gray scale, recording is performed with one color of black pigment ink as in the case of a glossy system. In the present specification, plain paper is paper that does not have the ink receiving layer, unlike a medium that has an ink receiving layer on a substrate such as the above-described OHP sheet. In other words, it is paper that is generally used in offices and the like.

  FIG. 9 is a block diagram showing an example of the configuration of the control system of the inkjet recording apparatus having the above configuration. In the figure, reference numeral 1010 denotes a control unit including a control means for controlling the type of ink used and the amount of ink used depending on the recording medium, for example, a personal computer, 1000 is an MPU for controlling each unit, and 1001 corresponds to the control procedure. A ROM 1002 storing programs and the like is a RAM used as a work area when executing the control procedure.

  An operation unit 107 and a printer unit 13 are connected to the control unit 1010 via an interface unit 1003. The control signal output from the control unit 1010 drives the recovery system unit 20, drives the recording head 1 via the head driver 25, and drives the carriage motor 21 via the motor driver 27. In addition to the personal computer as described above, the control unit 1010 may be built in the printer (in this case, the interface unit 1003 is unnecessary), or may be built in an input device such as a digital camera. The input image may be printed directly.

  FIG. 10 is a flowchart showing control of ink type selection executed by the control unit 1010 shown in FIG. 9, and more specifically, which of black pigment ink and dye color ink is selected according to the type of recording medium and the printing mode. It is a flowchart which shows whether is selected. In order to control which ink is used when recording the pixels corresponding to the image data, a signal indicating the type of the recording medium is determined, and then a signal indicating whether recording is performed by gray scale printing is determined. This determination determines the ink to be used and instructs the printer to record using the determined ink.

  If it is determined in step S1 that the type of the recording medium is a plain paper signal, the process proceeds to step S6, and it is determined whether the signal is a grayscale printing signal. If the signal is a grayscale printing signal, the process proceeds to step S11, where it is determined that the recording should be performed using only the pigment black ink. If it is not a grayscale printing signal in step S6, the process proceeds to step S12, where it is determined that the black pigment ink and the dye color ink should be recorded together.

  If it is determined in step S1 that the recording medium is not a plain paper signal, the process proceeds to step S2. If it is determined in step S2 that the type of the recording medium is a glossy medium signal, the process proceeds to step S7 to determine whether the signal is a grayscale printing signal. If the signal is a grayscale printing signal, the process proceeds to step S13, where it is determined that the recording should be performed using only the pigment black ink. If it is not a signal for gray scale printing in step S7, the process proceeds to step S12, where it is determined that recording should be performed using only the dye color ink.

  Hereinafter, since it is the same, it abbreviate | omits and demonstrates. When the type of the recording medium is a back print film signal, it is determined that the recording should be performed using only the dye color ink regardless of whether the signal is a gray scale printing signal.

  When the type of the recording medium is an OHP sheet signal, it is determined that the pigment black ink and the dye color ink should be recorded regardless of whether the signal is a grayscale printing signal.

  When the type of recording medium is a postcard signal, it is determined that the recording should be performed using only the pigment black ink when the signal is a grayscale printing, and when the signal is not the grayscale printing, It is determined that the recording should be performed in combination with the dye color ink.

  In the above embodiment, the operator inputs the type of the recording medium from an operation unit such as a printer driver. However, a sensor capable of automatically determining the type of the recording medium is provided in the printer 13, and the determination result is as follows. Control for selecting the ink type shown in FIG. 10 may be performed based on the above. In this case, since the type of the recording medium determined by the printer must be notified from the printer 13 to the control unit 1010, the interface unit 1003 needs to have a bidirectional communication function. Further, as a sensor for automatically discriminating the type of recording medium, it is considered effective to use an optical detection as disclosed in Japanese Patent Publication No. 5-23955.

  The ink suitable for the present invention will be described below.

  The pigment black ink is preferably composed of at least a pigment dispersion, a water-soluble organic solvent, and water.

  The pigment dispersion is obtained by dispersing a pigment in a liquid medium using a polymer dispersant.

  As the pigment, carbon black is preferable, and for example, NO. 2300, NO. 900, MCF. 88, NO. 33, NO. 40, NO. 45, NO. 52, MA7, MA8, NO. 2200B (Mitsubishi Kasei Co., Ltd.), Raven 1255 (Columbia Co., Ltd.), REGAL400R, REGAL330R, REGAL660R, MOGUL L (Made by Cabot Corporation), Color Black FW1, Color Black FW18, Color Black S170, Color Black S170, Color Black S170, Color Black S170, Color Black S170, Color Black S170, Color Black S170, Color Black S170 35, commercially available products such as Printex U (manufactured by Tegusa) may be used, or newly manufactured products may be used.

  As described above, the pigment constituting the black ink is dispersed in the aqueous liquid medium together with the water-soluble resin (dispersant). The aqueous liquid medium suitably used in this case is a mixed solvent of water and a water-soluble organic solvent, and as the water, ion-exchanged water (deionized water) is used instead of general water containing various ions. Is preferred. The water content used is in the range of 10 to 90% by weight, preferably 30 to 80% by weight of the total ink.

  Specific examples of the water-soluble organic solvent used by mixing with water include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl. C1-C4 alkyl alcohols such as alcohol; Amides such as dimethylformamide and dimethylacetamide; Ketones or ketoalcohols such as acetone and diacetone alcohol; Ethers such as tetrahydrofuran and dioxane; Polyethylene glycol, Polypropylene glycol, etc. Polyalkylene glycols; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol Alkylene glycols having 2 to 6 carbon atoms such as diethylene glycol; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether Lower alkyl ethers of monohydric alcohols; N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like. The water-soluble organic solvents as described above can be used alone or in combination.

  The content of the water-soluble organic solvent as described above contained in the black ink used in the present invention is generally preferably in the range of 3 to 50% by weight of the total ink, and more preferably 3 to 3%. A range of 40% by weight is preferred. In addition to the above components, the black ink used in the present invention is appropriately added with a surfactant, an antifoaming agent, a preservative, etc. as necessary to obtain an ink having a desired physical property value. In addition, commercially available water-soluble dyes and the like can be appropriately added.

  The ink used in the present invention is required to have characteristics that allow it to be ejected from an inkjet head. Examples of ink characteristics include a viscosity of 1 to 15 cP, preferably 1 to 5 cP, and a surface tension of 25 dyn / cm or more. Preferably it is 25-50 dyn / cm. And as a composition of the preferable aqueous liquid medium which can carry | support the above characteristics, glycerin, a trimethylol propane, thiodiglycol, ethylene glycol, diethylene glycol, isopropyl alcohol, acetylene alcohol etc. are included, for example.

  Next, the dye ink used as the color ink will be described.

  The dye ink comprises at least a water-soluble dye, water, and a water-soluble organic solvent.

  As the water-soluble dye, those used in ordinary ink jet recording methods can be used, and for example, acid dyes, direct dyes, and the like can be used.

As the anionic dye in the water-soluble dye used in the present invention, an existing anionic dye or a newly synthesized dye may be used as long as it has an appropriate color tone and density. Can do. Further, any of these can be mixed and used. Specific examples of the anionic dye include the following.
(Coloring material for yellow)
C. I. Direct yellow 8, 11, 12, 27, 28, 33, 39, 44, 50, 58, 85, 86, 87, 88, 89, 98, 100, 110
C. I. Acid Yellow 1, 3, 7, 11, 17, 23, 25, 29, 36, 38, 40, 42, 44, 76, 98, 99
C. I. Reactive Yellow 2, 3, 17, 25, 37, 42
C. I. Food yellow 3
(Coloring material for red)
C. I. Direct Red 2, 4, 9, 11, 20, 23, 24, 31, 39, 46, 62, 75, 79, 80, 83, 89, 95, 197, 201, 218, 220, 224, 225, 226, 227, 228, 230
C. I. Acid Red 6, 8, 9, 13, 14, 18, 26, 27, 32, 35, 42, 51, 52, 80, 83, 87, 89, 92, 106, 114, 115, 133, 134, 145, 158, 198, 249, 265, 289, C.I. I. Reactive Red 7, 12, 13, 15, 17, 20, 23, 24, 31, 42, 45, 46, 59
C. I. Food Red 87, 92, 94
(Coloring material for blue)
C. I. Direct Blue 1, 15, 22, 25, 41, 76, 77, 80, 86, 90, 98, 106, 108, 120, 158, 163, 168, 199, 226
C. I. Acid Blue 1, 7, 9, 15, 22, 23, 25, 29, 40, 43, 59, 62, 74, 78, 80, 90, 100, 102, 104, 117, 127, 138, 158, 161
C. I. Reactive Blue 4, 5, 7, 13, 14, 15, 18, 19, 21, 26, 27, 29, 32, 38, 40, 44, 100
As for the water-soluble solvent and water, the same solvents as those described for the pigment black ink can be used.

  In general, the content of the water-soluble organic solvent contained in the color ink used in the present invention is preferably in the range of 3 to 50% by weight, more preferably 3 to 40% by weight of the whole ink. The range is preferable. The water content contained in the color ink is preferably in the range of 50 to 90% by weight of the total ink.

  Similarly to the pigment black ink, the color ink is required to have characteristics that can be ejected from the ink jet head, and is preferably prepared so that the ink has a desired viscosity and surface tension.

  In the exemplary embodiment of the present invention, a storage medium recording software program codes for realizing the functions of the above-described exemplary embodiments is supplied to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. This is accomplished by reading and executing the program code stored in the.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, so that the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described exemplary embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code However, it is needless to say that some or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

  Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board is based on the instruction of the program code. It goes without saying that the CPU of the function expansion unit or the like performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

  The present invention provides an excellent effect particularly in a recording apparatus using an ink jet recording head that performs recording by forming flying droplets using thermal energy among ink jet recording methods.

  As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface, and as a result, bubbles in the liquid (ink) corresponding to the drive signal can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable that the drive signal has a pulse shape, since the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve discharge of a liquid (ink) having particularly excellent responsiveness. As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.

  As the configuration of the recording head, in addition to the combination configuration (straight liquid channel or right-angle liquid channel) of the discharge port, the liquid channel, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the thermal action A configuration using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which the portion is arranged in a bent region, is also included in the present invention.

  In addition, for a plurality of electrothermal transducers, Japanese Patent Application Laid-Open No. Sho 59-123670 that discloses a configuration in which a common slit is used as a discharge portion of the electrothermal transducer or an aperture that absorbs pressure waves of thermal energy is provided. The effect of the present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461 which discloses a configuration corresponding to the discharge unit. That is, whatever the form of the recording head is, according to the present invention, recording can be performed reliably and efficiently.

  Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by the recording apparatus. As such a recording head, either a configuration satisfying the length by a combination of a plurality of recording heads or a configuration as a single recording head formed integrally may be used.

  In addition, even the serial type as shown in the above example can be connected to the main body of the recording head or attached to the main body of the device so that electrical connection with the main body of the device and ink supply from the main body are possible. The present invention is also effective when a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself is used.

  In addition, it is preferable to add a recording head ejection recovery means, a preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention, since the effects of the present invention can be further stabilized. Specifically, heating is performed using a capping unit, a cleaning unit, a pressurizing or suction unit, an electrothermal transducer, a heating element different from this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

  Also, regarding the type or number of mounted recording heads, two or more recording heads may be provided corresponding to a plurality of inks having different recording colors and densities. That is, for example, as a recording mode of the recording apparatus, not only a recording mode of only a mainstream color such as black, but also a recording head may be configured integrally or by a combination of a plurality of different colors, Alternatively, the present invention is extremely effective for an apparatus having at least one of full-color recording modes by color mixing.

  In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, ink that is solidified at room temperature or lower and that softens or liquefies at room temperature may be used. In the ink jet system, the temperature of the ink itself is adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable discharge range. A liquid material may be used.

  In addition, it is solidified and heated in an untreated state in order to actively prevent the temperature rise caused by thermal energy from being used as the energy for changing the state of the ink from the solid state to the liquid state, or to prevent the ink from evaporating. You may use the ink which liquefies by. In any case, by applying thermal energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case of using ink having the property of being liquefied for the first time. The ink in such a case is in a state of being held as a liquid or a solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, the electrothermal converter may be opposed to the electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.

1 is a perspective view showing an example of an embodiment of an ink jet recording apparatus to which the present invention is applied. It is a figure of the property setting screen of the inkjet printer in the user interface of the driver software by this invention. FIG. 4 is a diagram showing which ink is used for recording according to the type of recording medium in the present invention. In the embodiment which concerns on this invention, it is a figure which shows the contour line of a black density | concentration at the time of forming a black area | region by mixing pigment black ink and dye color ink on the plastic sheet which provided the ink receiving layer. In the embodiment which concerns on this invention, it is a figure which shows black density when a pigment black ink is singly injected into the plastic sheet which provided the ink receiving layer. In the embodiment according to the present invention, it is a diagram showing the black density by the composite black formed with the dye color ink applied to the plastic sheet provided with the ink receiving layer, and formed by the dye color ink applied. In the embodiment according to the present invention, (FIG. 7A) is a diagram in which a black region is formed when recording is performed with only pigment black ink, and (FIG. 7B) is a pigment black ink and a dye color ink. It is the figure which formed the black area | region using together. In the embodiment according to the present invention, it is a diagram showing the amount of ink applied to the OHP sheet. It is a block diagram which shows an example of a structure of the control system of the inkjet recording device to which this invention is applied. 6 is a flowchart illustrating control of ink type selection performed by a control unit of an ink jet recording apparatus to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A Ink head of pigment black ink 1B Ink head of dye cyan ink 1C Ink head of dye magenta ink 1D Ink head of dye yellow ink 2 Carriage 3 Guide shaft 4 Main scanning motor 5 Motor pulley 6 Driven pulley 7 Timing belt 8 Recording medium 9 Conveying roller pair 10 Conveying roller pair 11 Conveying roller pair 12 Conveying roller pair 13 Inkjet printer 14 Personal computer 15 Cable 16 Pull-down menu for selecting “paper type” 17 Check box for designating “grayscale printing” 20 Recovery system unit 21 Carriage Motor 25 Head driver 27 Motor driver 1000 MPU
1001 ROM
1002 RAM
1003 Interface unit 1010 Control unit

Claims (12)

An ink jet recording method for recording an image using at least one of a black ink containing a black pigment and each color ink containing at least cyan, magenta and yellow dyes,
A step of recording an image including a black region by using the black ink and the color ink in combination on a light-transmitting recording medium having an ink receiving layer;
In the recording step, 30% to less than 70% of the area of the black region showing the highest density is recorded with the black ink, and the black region not recorded with the black ink is recorded with the color ink. Inkjet recording method.   2. The ink jet recording method according to claim 1, wherein 40% or more and less than 60% of the area of the black region showing the highest density is recorded with the black ink.   4. The ink jet recording method according to claim 3, wherein approximately 50% of the area of the black region showing the highest density is recorded with the black ink.   4. The ink jet recording method according to claim 1, wherein the light transmissive recording medium is an OHP sheet. An ink jet recording method for recording an image using at least one of a black ink containing a black pigment and each color ink containing at least cyan, magenta and yellow dyes,
In the case of recording a black image on a light-transmitting recording medium having an ink receiving layer, an ink jet recording method comprising: recording a region showing the highest density in the black image with both the black ink and the color ink. . An ink jet recording method using a recording apparatus capable of recording an image on a recording medium using a black ink containing a black pigment and each color ink containing at least cyan, magenta, and yellow dyes,
Determining the type of ink to be used based on at least a signal indicating the type of recording medium and the type of recording mode;
Recording on the recording medium using the determined ink, and
In the determination step,
When the signal indicating the type of the recording medium is a signal indicating a light transmissive recording medium having an ink receiving layer and the signal indicating the type of the recording mode is a signal indicating a monochrome mode, the highest density region in the black image is displayed. Determine the use of the black ink and the color ink for recording,
When the signal indicating the type of the recording medium is a signal indicating a light transmissive recording medium having an ink receiving layer and the signal indicating the type of the recording mode is a signal indicating a color mode, the highest density region in the black image An ink jet recording method comprising: determining use of the recording color ink and the black ink. In the determination step,
When the signal indicating the type of the recording medium is a signal indicating a glossy recording medium having an ink receiving layer on a substrate and the signal indicating the type of the recording mode is a signal indicating a monochrome mode, the black ink Determine use and non-use of the color ink,
When the signal indicating the type of the recording medium is a signal indicating a glossy recording medium having an ink receiving layer on a substrate and the signal indicating the type of the recording mode is a signal indicating a color mode, the black ink 7. The ink jet recording method according to claim 6, wherein non-use and use of the color ink are determined. In the determination step,
When the signal indicating the type of the recording medium is a signal indicating a postcard and the signal indicating the type of the recording mode is a signal indicating a monochrome mode, the use of the black ink and the non-use of the color ink are determined,
When the signal indicating the type of the recording medium is a signal indicating a postcard and the signal indicating the type of the recording mode is a signal indicating a color mode, the combined use of the color ink and the black ink is determined. The inkjet recording method according to claim 6 or 7. In the determination step,
The signal indicating the type of the recording medium is a signal indicating the recording medium observed from the opposite side of the surface on which the ink receiving layer is provided, and the signal indicating the type of the recording mode is a signal indicating the monochrome mode. The non-use of the black ink and the use of the color ink,
The signal indicating the type of the recording medium is a signal indicating the recording medium observed from the opposite side of the surface on which the ink receiving layer is provided, and the signal indicating the type of the recording mode is a signal indicating the color mode. 9. The inkjet recording method according to claim 6, wherein the non-use of the black ink and the use of the color ink are determined.   The inkjet recording method according to claim 9, wherein the recording medium observed from the side opposite to the surface on which the ink receiving layer is provided is at least one of a back print film and a T-shirt transfer medium. The recording medium ejecting the black ink containing the black pigment and the ejection parts ejecting the respective color inks containing at least cyan, magenta and yellow dyes are scanned relative to the recording medium. An inkjet recording apparatus for recording an image,
When recording an image including a black region by using the black ink and the color ink together on a light-transmitting recording medium having an ink receiving layer, the area of the black region showing the highest density is 30% or more and less than 70%. Is recorded with the black ink, and a black region not recorded with the black ink is recorded with the color ink. The recording medium ejecting the black ink containing the black pigment and the ejection parts ejecting the respective color inks containing at least cyan, magenta and yellow dyes are scanned relative to the recording medium. An inkjet recording apparatus for recording an image,
When the type of the recording medium is a light transmissive recording medium having an ink receiving layer and the type of recording mode is a monochrome mode, the highest density area of a black image is recorded using the color ink and the black ink together. Done
When the type of the recording medium is a light-transmitting recording medium having an ink receiving layer and the type of recording mode is a color mode, the highest density area of a black image is recorded by using the color ink and the black ink together. An ink jet recording apparatus characterized in that

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