Patent Application
20140354718
1. Technical Field
The present invention relates to a printing device and a method of controlling the printing device.
2. Related Art
As a printing device, there is an ink jet printer (hereinafter, referred to as a printer) having a head for discharging inks from nozzles to a medium, and a printer for performing printing using a white ink in addition to monochromic printing or color printing is known. In such a printer, for example, a color image is printed on a white background image so as to improve a color development property of the color image.
In addition, an image may be printed on a transparent film or the like as well as a paper medium. A printer capable of selecting a mode for printing a white background image on a medium and printing a color image on the background image or a mode for printing the color image on one surface of the medium and printing the white background image on the other surface of the medium at the same position where the color image is printed is suggested (for example, see JP-A-2009-56613).
However, in an ink jet printer, a limit value of the amount of ink dischargeable per unit area according to the property of an ink or a medium is set. As described above, in a mode for superposing and printing a white background image and a color image, as compared with a mode for printing only a color image, even when the same color image is printed, the amount of discharged ink per unit area of the medium is increased by the amount of white ink. Therefore, if the limit value of the amount of ink dischargeable per unit area is set regardless of the printing mode, in the mode for superposing and printing two images, the ink which is not absorbed into the medium flows out, the image is blurred, and image quality of the printed image deteriorates.
An advantage of some aspects of the invention is that deterioration in image quality of a printed image is suppressed.
According to an aspect of the invention, there is provided a printing device including: nozzles which discharge a first aqueous ink for printing a main image; nozzles which discharge a second aqueous ink for printing a background image; and a control unit which controls printing of an image on a medium having an aqueous ink absorption property based on one selected from a first mode for printing the main image using the first aqueous ink and a second mode for superposing and printing the main image using the first aqueous ink and the background image using the second aqueous ink, wherein the amount of first aqueous ink dischargeable per unit area of the medium when the main image is printed on the medium in the second mode is less than that when the main image is printed on the medium in the first mode.
The other features of the invention will be apparent from the present specification and the accompanying drawings.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
The following matter will be apparent from the present specification and the accompanying drawings.
That is, a printing device includes nozzles which discharge a first aqueous ink for printing a main image; nozzles which discharge a second aqueous ink for printing a background image; and a control unit which controls printing of an image on a medium having an aqueous ink absorption property based on one selected from a first mode for printing the main image using the first aqueous ink and a second mode for superposing and printing the main image using the first aqueous ink and the background image using the second aqueous ink, wherein the amount of first aqueous ink dischargeable per unit area of the medium when the main image is printed on the medium in the second mode is less than that when the main image is printed on the medium in the first mode.
According to the printing device, it is possible to prevent the aqueous ink from being discharged when this would exceed the absorption capability of the medium and to prevent blurring of the printed image.
In the printing device, the total amount of first aqueous ink and second aqueous ink dischargeable per unit area of the medium in the second mode is greater than the amount of first aqueous ink dischargeable per unit area of the medium in the first mode.
According to the printing device, it is possible to improve the color development property of the main image while preventing blurring of the printed image.
In the printing device, a predetermined drying time is provided while the main image and the background image are respectively printed in the second mode.
According to the printing device, it is possible to set the total amount of first aqueous ink and second aqueous ink dischargeable per unit area in the second mode to be greater than the amount of first aqueous ink dischargeable per unit area in the first mode.
In the printing device, while a first nozzle array in which the nozzles for discharging the first aqueous ink are arranged in a predetermined direction, a second nozzle array in which the nozzles for discharging the second aqueous ink are arranged in the predetermined direction, and the medium are relatively moved in a movement direction intersecting the predetermined direction, an image forming operation for discharging the aqueous inks from the nozzles and an operation for moving the relative position between the first nozzle array and second nozzle array and the medium in one direction of the predetermined direction are repeated so as to print the image on the medium, and, in the second mode, of the main image and the background image, the nozzles for forming a first printed image in a predetermined area on the medium are located on the other direction side of the predetermined direction of the nozzles for forming a subsequently printed image in the predetermined area.
According to the printing device, it is possible to set the total amount of first aqueous ink and second aqueous ink dischargeable per unit area in the second mode to be greater than the amount of first aqueous ink dischargeable per unit area in the first mode.
In the printing device, the total amount of first aqueous ink and second aqueous ink dischargeable per unit area of the medium in the second mode is equal to the amount of first aqueous ink dischargeable per unit area of the medium in the first mode.
According to the printing device, it is possible to prevent blurring of the printed image.
In the printing device, in the second mode, the ink amount per one color of the second aqueous ink dischargeable per unit area of the medium is less than the ink amount per one color of the first aqueous ink dischargeable per unit area of the medium.
According to the printing device, it is possible to improve the color development property of the main image.
In the printing device, the background image is printed using the second aqueous ink and the first aqueous ink.
According to the printing device, it is possible to print the background image of a desired color.
A method of controlling a printing device including nozzles for discharging a first aqueous ink for printing a main image and nozzles for discharging a second aqueous ink for printing a background image includes executing an operation for selecting one from a first mode for printing the main image using the first aqueous ink and a second mode for superposing and printing the background image using the second aqueous ink; and executing an operation for setting the amount of first aqueous ink dischargeable per unit area of a medium having an aqueous ink absorption property to a predetermined amount and printing an image on the medium, if the first mode is selected, and setting the amount of first aqueous ink dischargeable per unit area of the medium to be less than the predetermined amount and printing the image on the medium, if the second mode is selected.
According to the method of controlling the printing device, it is possible to prevent the aqueous ink from being discharged when this would exceed the absorption capability of the medium and to prevent blurring of the printed image.
Hereinafter, a printing device is an ink jet printer (hereinafter, referred to as a printer), and an embodiment will be described using a printing system, in which the printer and a computer are connected, as an example.
The printer 1 which receives a printing command and printing data from the computer 60 controls units by a controller 10 so as to print an image on a medium S. A detector group 50 monitors the internal status of the printer 1 and the controller 10 controls the units based on a detection result. An interface unit 11 in the controller 10 performs data transmission/reception between the computer 60, which is an external device, and the printer 1. A CPU 12 is an arithmetic processing unit for controlling the overall printer 1. A memory 13 secures a region for storing a program of the CPU 12, a work area, or the like. The CPU 12 controls the units by a unit control circuit 14.
A transport unit 20 feeds the medium S to a printable position and transports the medium S by a predetermined transport amount in a transport direction at the time of printing.
A carriage unit 30 moves the head 41 in a direction (hereinafter, referred to as a movement direction) intersecting the transport direction and has a carriage 31.
A head unit 40 discharges inks to the medium S and includes the head 41. The head 41 is moved by the carriage 31 in the movement direction. A plurality of nozzles which is an ink discharge unit is formed in a lower surface of the head 41 and a pressure chamber (not shown) in which the ink is filled is provided in each nozzle.
In such a printer 1, a dot forming process of intermittently discharging ink droplets from the head 41 moving along the movement direction so as to form dots on the medium and a transport process of transporting the medium relative to the head 41 in the transport direction are repeated. Therefore, it is possible to form dots at positions different from the positions of dots formed by a previous dot forming process and to print a two-dimensional image on the medium. In addition, an operation (one dot forming process) for moving the head 41 once in the movement direction while discharging ink droplets is called a “pass”.
A first printing mode is a “general color mode (corresponding to a first mode)”, in which only a color image (hereinafter, referred to as a main image) is printed on a medium using four color ink nozzle arrays (YMCK). Therefore, in the general color mode, the white nozzle array W is not used. A second printing mode is a “front-surface printing mode (corresponding to a second mode)”, in which a background image is first printed in a predetermined area of a medium using the white nozzle array W and a main image is then printed on the background image using the four color ink nozzle array (YMCK). A third printing mode is a “rear-surface printing mode (corresponding to a third mode)”, in which a main image is first printed in a predetermined area of a medium using the four color ink nozzle arrays (YMCK) and a background image is then printed on the main image using the white nozzle array W. In the front-surface printing mode or the rear-surface printing mode, since the main image of the four color inks and the background image of the white color are superposed and printed, the color development of the main image is excellent. Even when the main mage is printed on a transparent medium (hereinafter, referred to as a transparent film), it is possible to prevent an opposite side of the main image from being transparent. Since an image is printed on a transparent film, as shown in
When the background image is printed using only the white ink, the white ink used to print the background image becomes the color of the background image. However, even in the same white ink, the hue of the white color varies slightly depending on the material of the ink or the like. Accordingly, a background image of a color different from a color desired by the user may be printed when using the white ink. In a certain printed material, a background image having a slight chromatic color may be desired to be used instead of a simple white color. If a white medium is used, even in the white medium, the hue of the white color varies slightly depending on the type of the medium. Therefore, when the background image is printed on the white medium, if the white color of the background image is different from the white color of the medium, the background image thus becomes conspicuous.
In the present embodiment, the background image of a desired white color (background image of an adjusted white color) is printed appropriately using a small amount of color inks (YMCK) together with the white ink. That is, when the background image is printed, a color ink of at least one of the color inks capable of being discharged from the printer 1 may be used. For example, all the color inks of four colors may be used or color inks of two colors may be used. In the case where the white ink has a slight hue by printing the background image using the white ink and the color inks, the background image may be approximated to an achromatic color by printing the background image together with an ink for canceling the hue.
In addition, printing data for printing the background image of the desired white color in the printer 1 may be stored in the printer 1 in advance or prepared by the printer driver. In the case where the user views the screen of the computer or the monitor of the printer 1 and selects the desired color of the background image, the printing data of the background image according to the selected color may be generated.
First, in the front-surface printing mode (
First, in the rear-surface printing mode (
When the main image and the background image are superposed and printed, the nozzles located on the upstream side of the nozzles for subsequently printing the image in the transport direction are set as the nozzles for first printing the image with respect to the predetermined area on the medium. Accordingly, it is possible to secure the drying time of the first printed image. As a result, even when two images are superposed and printed, it is possible to suppress blurring of the image.
The position of the transport direction of the nozzles A of the white nozzle array W for printing the background image and the position of the transport direction of the nozzles 0 of the color nozzle array Co for printing the background image are equalized. In order to print the background image, the white ink and the color ink are sprayed to the predetermined area of the medium in the same pass. As a result, the white ink and the color ink are mixed so as to deteriorate granularity of the background image.
The fraction of the color ink configuring the background image is less than the fraction of the white ink. In order to reduce granularity of the color ink in the background image, it is preferable that the dots of the color ink are uniformly dispersed. That is, the color ink density (dot density) per unit area of the background image is less than the white ink density (dot density) per the unit area of the background image. Therefore, the fraction of the color ink configuring the background image is less than the fraction of the white ink, but, in the present embodiment, the number of nozzles of the white nozzle array W used for printing the background image and the number of nozzles of the color nozzle array Co are equalized. That is, the background image is printed using the nozzles corresponding to half of the color nozzle array Co. The invention is not limited thereto and the background image may be printed using several nozzles of the nozzles corresponding to half of the color nozzle array Co which can be used for printing the background image.
Hereinafter, the ink discharge amount per unit area of the medium according to the printing mode will be described. In the present embodiment, the background image is printed using the white ink and at least one of the four color inks. The base color of the medium needs to be hidden by the white ink of the background image so as to protect the main image. Meanwhile, a slight chromatic color may be applied to the background image by the color ink for the background image. In order to enhance granularity of the color inks for the background image, the dot size of the color inks may be minimized. Accordingly, in order to form the background image, the color ink discharge amount per unit area of the medium is less than the white ink discharge amount per unit area of the medium. Therefore, the color ink discharge amount per unit area of the medium in order to form the background image has little influence on the maximum amount of ink dischargeable per unit area of the medium (duty limit value which will be described in detail later). Accordingly, hereinafter, for simplification of description, the ink for forming the background image is the white ink.
The ink used in the present embodiment may be an ink composition absorbed into a medium having an ink absorption property as an ink absorbed into the medium having an ink absorption property, is an “aqueous ink” including at least water as a solvent in order to secure the absorption property to the medium having the ink absorption property, and includes a pigment or a dye as a color material. For discharge stability from the ink jet head, an aqueous organic solvent may be included or a moisturizing agent, a penetration-enhancing agent, a pH adjuster, an insecticide, an ultraviolet absorbing agent or the like may be included if necessary. As the color inks (YMCK corresponding to a first aqueous ink) having such a composition, for example, the ink described in JP-A-2008-81693, JP-A-2005-105135 and JP-A-2003-292834 may be used. A white ink composition includes a hollow resin as a color material or a white pigment such as titanium oxide, and the components other than the color material are identical to that of the color inks. As the white ink (corresponding to a second aqueous ink), for example, the ink described in JP-A-2009-138078 and JP-A-2009-137124 may be used.
The recording medium used in the present embodiment absorbs a solvent of the ink composition and the color material of the ink composition is adhered thereto. For example, a medium using a base material which absorbs an ink, such as paper or clothes, may be used or an ink absorption layer which absorbs an ink may be provided on a base material which absorbs ink or a base material which does not absorb an ink. In particular, if a transparent medium is used, the three printing modes shown in
As described above, in the printer 1 of the present embodiment, the aqueous ink is discharged from the nozzles such that the printed material shown in
In the printer 1, with respect to the used inks (YMCKW), a limit value of the amount of ink dischargeable per unit area of the medium is preset. In addition, the amount of ink dischargeable per unit area of the medium corresponds to a duty limit value (%), it may be set as the duty limit value. The duty limit value indicates a ratio of the number of dots (the amount of ink) actually dischargeable by the printer 1 according to the absorption capability of the medium to the number of dots (the amount of ink) dischargeable by the printer 1 per unit area of the medium. In order to prevent bleeding of the image, printing is performed using an amount of ink dischargeable per unit area less than with the limit value (duty limit value). Accordingly, in the present embodiment, when the printer driver in the computer 60 creates printing data, the amount of ink dischargeable per unit area (duty limit value) is considered. Since the ink absorption capability is changed according to the type of the medium, if the printer can print an image on various types of medium, the limit value of the amount of ink dischargeable per unit area of each medium may be set. For simplification of description, a medium on which the printer 1 prints an image is set to one type “transparent film having an ink absorption layer”.
In order to prevent the ink of an amount exceeding the ink absorption capability of the medium from being discharged, the amount of ink discharged at image data having a maximum concentration may be limited. That is, the ink discharge amount per unit area of the medium may be set to a maximum amount of ink dischargeable per unit area of the medium by the image data in which the gradation value of all the pixels belonging to the unit area is a maximum gradation value. For example, a black dot is formed alone. If the gradation value of black displayed by each of 100 pixels (10×10 pixels) belonging to the unit area is 255 and the gradation values of cyan, magenta and yellow are 0, the ink discharge amount per unit area is set to the maximum amount of ink dischargeable per unit area of the medium. In addition, the ink discharge amounts in the gradation values of the other color inks may be set based on the ink discharge amount in the maximum gradation value of black.
First, the printing mode is selected (S101). In the case where the printer driver receives image data of a main image from an application program and prints the main image on a transparent medium (for example, a transparent film having an ink absorption layer), a window is displayed on a display device (display or the like) so as to enable the user to select one of three types of printing mode (general color mode, front-surface printing mode, and rear-surface printing mode) shown in
Next, a resolution conversion process (S102) is performed. The resolution conversion process indicates a process of converting the image data received from the application program into resolution when an image is printed on paper S.
Next, a color conversion process (S103) is performed. The color conversion process indicates a process of converting RGB image data into data having a multi-level gradation value shown by YMCK color spaces. This color conversion process is performed by referring to a table (color conversion lookup table) in which RGB luminance values correspond to YMCK gradation values.
Next, the printing mode is determined (S104). The determination of the printing mode is performed by referring to the printing mode stored in the memory of the computer 60. If the printing mode set by the user is the general color mode (S104->Y), a halftone process for the general color mode is performed (S105, which will be described in detail later). In the general color mode, since only the main image is printed using four color inks YMCK, the halftone process for YMCK image data is performed. The halftone process indicates a process for converting YMCK(W) image data having a multi-level gradation value into small-level gradation data expressible by the printer 1. In the present embodiment, by the halftone process, the YMCK(W) data indicating 256-level gradation value per pixel is converted into 2-bit dot identification data indicating 4-level gradation value. That is, dot identification data (2-bit data) of “00” indicating that a dot is not formed, “01” indicating that a small dot is formed, “10” indicating that a middle dot is formed, and “11” indicating that a large dot is formed is set to each pixel.
Meanwhile, if the printing mode is not the general color mode, that is, if it is the front-surface printing mode or the rear-surface printing mode (S104->N), a background image (background image data) creation process is performed (S106). In the front-surface printing mode or the rear-surface printing mode, the main image using the four color inks (YMCK) and the background image using the white ink are superposed and printed. In the background image creation process, the data of the background image, that is, the image data of the white ink (W) is created in accordance with the size of the printed main image. Here, the background image is a painted-out image using the white ink and the size of the background image is larger than that of the main image by a predetermined margin amount. Thereafter, a halftone process for the YMCK image data for the main image and the W image data for the background image is performed as the halftone process for the front-surface printing mode and the rear-surface printing mode (S107, which will be described in detail later).
Finally, a rasterization process (S108) is performed. The rasterization process indicates a process of changing a dot identification data which can be obtained by the halftone process into order of data to be transmitted to the printer 1. The dot identification data subjected to the rasterization process is sent to the printer 1 as printing data, together with command data or the like. The printer 1 performs printing according to the received printing data.
First, the printer driver acquires the YMCK image data after the color conversion process (S103 of
Hereinafter, the flow of the halftone process will be described. First, as shown in step S202 of
Next, in step S203, it is determined whether or not the set level data LVL is greater than a threshold THL. Here, dot ON/OFF determination of the dot is performed according to the dither method. The threshold THL uses a matrix in which each pixel block of a dither matrix is expressed by a value of 0 to 255. In addition, the threshold is set per dot size, a threshold for a large dot is set to THL, a threshold for a middle dot is set to THM, and a threshold for a small dot is set to THS.
In contrast, if the process progresses to step S204, the printer driver sets the level data LVM of the middle dot. The level data LVM of the middle dot is read from the profile MD (thick line of
In step S205, if the level data LVM for the middle dot is greater than the threshold THM for the middle dot (S205->Y), it is determined that the middle dot is set to ON, and the process progresses to step S210, otherwise (S205->N), the process progresses to step 206. When the process progresses to step S210, the printer driver records the K pixel data to be processed in correspondence with the dot identification data “10” indicating the middle dot creation, and a determination is made as to whether there are K pixel data to be subsequently processed or the process is finished.
Meanwhile, when the process progresses to step S206, similar to the level data of the large dot or the middle dot, the level data LVS of the small dot is set from the profile SD (narrow line of
The maximum amount of ink dischargeable per unit area of the medium (duty limit value) is added to the dot generation rate table (
The dot generation rate table for the four color pixel data (YMCK) of the general color mode shown in
That is, even with the same maximum amount of ink dischargeable per unit area (duty limit value), a maximum of four color (YMCK) dots is superposed and formed with respect to one pixel in the general color mode, whereas a maximum of five color (YMCK+W) dots is superposed and formed with respect to one pixel in the front-surface/rear-surface printing mode. Accordingly, as compared with the general color mode, in the front-surface/rear-surface printing mode, it is necessary to reduce the total amount of four color (YMCK) inks dischargeable per unit area by the amount of white ink. If the halftone process for the YMCK image data of the front-surface/rear-surface printing mode is performed using the dot generation rate table (
In detail, as shown in
Accordingly, even in the case where the main image and the background image are superposed and printed in the front-surface/rear-surface printing mode, it is possible to prevent the ink of the amount exceeding the absorption capability of the medium from being discharged. As a result, it is possible to prevent bleeding from occurring in the image and to suppress deterioration in image quality of the printed image. In other words, if the halftone process of the YMCK image data of the general color mode is performed using the dot generation rate table (
In a high gradation value (for example, 255), only the large dots are formed in the general color mode, whereas three types of dots are formed in the front-surface/rear-surface printing mode. As described above, generally, it is possible to improve the color development property of the image in respect to the ink discharge amount per unit area. However, since the maximum ink discharge amount per unit area (duty limit value) of the front-surface/rear-surface printing mode is less than that of the general color mode, the color development property of the main image using the four color inks (YMCK) is reduced. Instead, in the front-surface/rear-surface printing mode, since the middle dots and the small dots are generated even in the high gradation, it is possible to enhance the granularity of the image.
In the present embodiment, when the halftone process for the front-surface/rear-surface printing mode is performed, the dot generation rate table (
Since the background image using the white ink is superposed and formed on the main image using the four color inks, the protecting property for the main image can be secured by printing the background image, and the need to improve the color development property of the image is low in the background image, as compared with in the main image using the four color inks. Accordingly, even when the amount of each color ink discharged per unit area in order to form the background image is less than the amount of each color ink discharged per unit area in order to form the main image using the four color inks, a problem does not occur. By setting the dot generation rate (
As can be seen from
In the present embodiment, the dot generation rate (
The maximum ink amount dischargeable per unit area (duty limit value) is related to an ink discharge period. Even in the case where the same amount of ink is discharged with respect to the unit area, the ink which cannot be absorbed into the medium more easily flows out on the medium when the ink is discharged once for a short period of time, as compared with when the ink is discharged several times. That is, it is possible to increase the maximum ink amount (duty limit value) dischargeable per unit area when the ink is divisionally discharged plural times with respect to the unit area, as compared with when the ink is discharged once for a short period of time.
The four color inks (YMCK) are discharged with respect to the unit area in one pass in the general color mode, whereas the four color inks (YMCK) and the white ink (W) are discharged with respect to the unit area in two passes in the front-surface/rear-surface printing mode, the total amount of five color inks dischargeable per unit area in the front-surface/rear-surface printing mode may be greater than the total amount of four color inks dischargeable per unit area in the general color mode. As a result, while the ink discharge amount for printing the main image in order to suppress bleeding in the front-surface/rear-surface printing mode is reduced as compared with the general color mode, it is possible to increase the amount of ink for printing the main image as much as possible by providing a drying time while the main image and the background are printed. As a result, it is possible to improve the color development property of the main image. The invention is not limited to the printing method shown in
The drying time provided while the main image and the background image are printed may be provided between passes or in the same pass. The printer may be a line printer which individually includes a line head (a plurality of heads arranged in a paper width direction) for printing the main image and a line head for printing the background image. In this printer, a time when the medium is transported between two line heads may be the drying time while the main image and the background image are printed. The medium may be heated at the drying time when the main image and the background image are printed.
In this case, the sum of the amount (thin dotted line d7) of white ink discharged to the unit area in the front-surface/rear-surface printing mode and the amount (thick dotted line d6) of four color inks (YMCK) discharged to the unit area in the front-surface/rear-surface printing mode becomes the amount (solid line D5=D6+D7) of four color (YMCK) inks discharged to the unit area in the general color mode.
Although the background image in which the hue of the white color is adjusted using the white ink and the color inks is described as an example in the above-described embodiment, the invention is not limited thereto. The background image printed using only the white ink may be printed. However, in this case, only the background image using the white ink can not be printed. Therefore, a background image of a desired color may not be printed or a difference between the color of the background image and the background color of the medium may become conspicuous. Accordingly, a high-quality background image cannot be printed. Hereinafter, an example of printing the background image using only the white ink will be described.
First, in the front-surface printing mode (
Meanwhile, in the rear-surface printing mode (
In the case where the main image of the four color inks (YMCK) and the background image of the white ink are superposed and printed, the nozzles for first printing the image are set to be located on the upstream side of the nozzles for subsequently printing the image in the transport direction with respect to the predetermined area on the medium. Since the first formed image and the subsequently formed image can be printed in different passes, it is possible to secure the drying time of the first formed image. As a result, even when two images are superposed and printed, it is possible to suppress blurring of the image.
Although the color image is printed using only the four color inks (YMCK) in the above-described embodiment, the invention is not limited thereto. For example, the color image may be printed using the white ink together with the four color inks. In this case, in the front-surface printing mode shown in
Although the printing system having the ink jet printer as a main component is described in the embodiments, the disclosure of the creation of the printing data or the like is included. The above embodiments are described to facilitate the understanding of the invention and are not interpreted to restrict the invention. Modifications and changes of the invention may be made without departing from the scope of the invention and the invention includes equivalents thereof.
In the invention, an ink and a medium (ink absorption recording medium) having an ink absorption property to absorb the ink are used. As the ink absorption recording medium, a recording medium formed of a base material having an ink absorption property or a recording medium including an ink reception layer formed on a base material may be used. As the base material having the ink absorption property, there is paper, clothes or the like. As the base material including the ink reception layer formed thereon, a base material having an ink absorption property or a base material which does not absorb an ink may be used. As a material of the base material, for example, a resin film such as a polyester film, a polyolefin film or polyvinyl chloride, paper such as regular paper, coated paper or tracing paper, resin coated paper, synthetic paper, or the like may be used.
As the ink reception layer, a known ink reception layer generally provided on a recording medium for an ink jet recording method may be used. As the known ink reception layer, for example, an ink reception layer formed of a resin is known. As an example of the resin used in the ink reception layer, for example, various polymers having an ink absorption property such as polyvinyl pyrrolidone or vinyl pyrrolidone acetate copolymer disclosed in JP-A-57-38185, JP-A-62-184879 or the like, a poly(vinyl alcohol)-based resin composition disclosed in JP-A-60-168651, JP-A-60-171143, or JP-A-61-134290, a copolymer of vinyl alcohol and olefine or stylene and maleic anhydride disclosed in JP-A-60-234879, a cross linking substance of polyethylene oxide and isocyanate disclosed in JP-A-61-74879, a mixture of carboxymethylcellulose and polyethylene oxide disclosed in JP-A-61-181679, a polymer in which methacrylamide is grafted to polyvinyl alcohol disclosed in JP-A-61-132377, an acrylic polymer having a carboxyl group disclosed in JP-A-62-220383, a polyvinyl acetal-based polymer disclosed in JP-A-4-214382 or the like, a cross-linking acrylic polymer disclosed in JP-A-4-282282 or JP-A-4-285650, or the like may be used.
As the known ink reception layer, an ink reception layer in which a polymer matrix formed of a cross-linking polymer and an absorption polymer are concurrently used is disclosed in JP-A-4-282282, JP-A-4-285650 or the like. Further, an ink reception layer using hydrated alumina (cationic hydrated alumina) is known, and, for example, JP-A-60-232990, JP-A-60-245588, JP-B-3-24906, JP-A-6-199035, JP-A-7-82694 or the like discloses a recording medium in which fine pseudo-boehmite-form alumina hydrate is applied on a surface of a base material together with an aqueous binder. For example, JP-A-10-203006 discloses an ink reception layer using synthetic silica using a gas phase method, in which a primary particle diameter is mainly 3 nm to 30 nm. Further, JP-A-2001-328344 discloses an ink reception layer including an inorganic pigment and a polymer adhesive. In the invention, a film base material including each of the above-described ink reception layer formed thereon may be preferably used.
In the invention, as the composition of the white ink for the background image, a certain white ink composition which is generally used in an ink jet recording method may be used. As such a white pigment, for example, an inorganic white pigment, an organic white pigment, or white hollow polymer microparticle may be used. As the white ink composition, an aqueous ink composition containing hollow polymer microparticle as a coloring agent component is preferably used.
As the inorganic white pigment, alkaline earth metal sulphate such as barium sulfate, alkaline earth metal carbonate such as calcium carbonate, silicas such as fine powdered silicic acid or synthetic silicate, calcium silicate, alumina, hydrated alumina, titanium oxide, zinc oxide, talc, clay or the like may be used. In particular, titanium oxide is known as a white pigment which is preferable in protecting, coloring, and dispersion particle diameter.
As the organic white pigment, organic compound salt disclosed in JP-A-11-129613 or alkylenebismelamine derivative disclosed in JP-A-11-140365 or JP-A-2001-234093 may be used. As a detailed product of the white pigment, there is ShigenoxOWP, ShigenoxOWPL, ShigenoxFWP, ShigenoxFWG, ShigenoxUL, ShigenoxU (all of which are made by Hakkooru Chemical Co., Ltd. and are product names) or the like.
The hollow polymer microparticle contained as the coloring agent component may be a particle having an outer diameter of about 0.1 to 1 μm and an inner diameter of about 0.05 to 0.8 μm, should not be soluble in a solvent of a white ink composition, and should not chemically react with the other component, for example, a binder resin component.
In each of the hollow polymer microparticles, a wall is formed of a synthetic polymer to which a liquid is permeable both inwards and outwards, and the liquid can go in or out a space of a central portion of the hollow polymer microparticle through the wall. The space of the central portion of the hollow polymer microparticle is filled by a solvent in an ink composition state, the specific gravity of the hollow polymer microparticle and the specific gravity of the ink composition are substantially equal, and the hollow polymer microparticles are stably dispersed in the ink composition. When this ink composition is printed on a printed surface and is dried, the space of the central portion of the hollow polymer microparticle is replaced with air. Therefore, incident light is irregularly reflected in the resin and the space and a white color is substantially exhibited.
The hollow polymer microparticle may be of a type, in which the liquid is contained in the microparticle before printing, but the liquid contained in the microparticle is diffused through the wall of the microparticle after printing so as to fill a fine hole of the microparticle with air, as described above, or a fully sealed type in which air is contained from the beginning
Since it is preferable that the hollow polymer microparticle used in the white ink composition is not precipitated in the ink composition, the hollow polymer microparticle preferably has the same specific gravity as the ink composition solution. Therefore, as necessary, the specific gravity of the ink composition solution is preferably adjusted using a specific gravity-regulating agent such as glycerol.
As a commercially available product of the hollow polymer microparticle satisfying the above-described property, for example, Ropaque OP-62 commercially available from Rohm and Haas Company may be used. This is an aqueous dispersion containing 38-wt % hollow polymer microparticles formed of an acrylic/styrene copolymer. The inner diameter of this microparticle is about 0.3 μm, the outer diameter thereof is about 0.5 μm, and water is filled therein.
The hollow polymer microparticle can be obtained by a known manufacturing method, for example, a method disclosed in U.S. Pat. No. 4,089,800. This hollow polymer microparticle is substantially formed of an organic polymer and exhibits a thermoplastic property. As the thermoplastic resin used to manufacture the hollow polymer microparticle, preferably, a copolymer of a cellulose derivative, an acrylic resin, polyolefin, polyamide, polycarbonate, polystyrene, styrene or another vinyl monomer, a vinyl polymer such as a homopolymer or copolymer of vinyl acetate, vinyl alcohol, vinyl chloride or vinyl butyral, a homopolymer and copolymer of diene, or the like may be used. In particular, as the preferable thermoplastic polymer, a copolymer such as 2-hexyl acrylate copolymer or methyl methacrylate, a copolymer of styrene and another vinyl monomer such as acrylic nitrile may be used.
The content of the hollow polymer microparticles in the white ink composition used in the invention may be, for example, 0.1 to 20 wt %. If the content of the hollow polymer microparticles is equal to or greater than 0.1 wt %, a sufficient degree of whiteness can be obtained. If the content of the hollow polymer microparticles is equal to or less than 20 wt %, a sufficient amount of ink binder resin component necessary for securing the viscosity required in the ink composition for ink jet printing can be contained and, as a result, a sufficient printing adhesion property can be secured.
In the invention, the above white pigment may be used alone or in combination. In the dispersion of the pigment, a ball mill, a sand mill, an Attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, a paint shaker or the like may be used. When the pigment is dispersed, a dispersing agent may be added.
The white ink composition used in the present invention may contain various components generally contained in the ink composition for ink jet printing, for example, a resin component, a dispersing agent component, a solvent component (in particular, water) or the like, in addition to a white coloring agent component. In addition, in the present specification, the solvent and the solvent medium have the same meaning. As the white ink composition containing the hollow polymer microparticles as the white coloring agent, for example, a composition disclosed in Japanese Patent No. 3562754 or Japanese Patent No. 3639479 may be used.
The non-white ink composition for the color image used in the invention is, for example, a color ink composition, a black ink composition or a gray ink composition. As the color ink composition, for example, a cyan ink composition, a magenta ink composition, a yellow ink composition, a light cyan ink composition, a light magenta ink composition, a red ink composition, a green ink composition, or a blue ink composition or the like may be used. The non-white ink composition may be a combination of one or two or more of the above-described various ink compositions.
As the non-white ink composition, a certain non-white ink composition which is generally used in the ink jet recording method may be used, and an aqueous ink composition containing a dye or a pigment as the coloring agent component may be preferably used. In particular, an ink composition exhibiting a good property (for example, a color development property or fixability) with respect to a transparent film base material or an ink reception layer may be preferably used.
Although the difference in the amount of ink dischargeable per unit area (duty limit value) between the general color mode and the front-surface/rear-surface printing mode is applied to the dot generation rate table (
Although the background image is printed using the white ink in the above-described embodiments, the invention is not limited thereto and the background image may be printed using a color ink (for example, a metallic ink) other than the white ink. The invention is not limited to the printing of the background image using only the white ink, the other color inks may be mixed to the white ink and the background image in which the hue of the white color is adjusted may be printed or the main image may be printed by adding the white ink to the four color inks (YMCK). If the other color inks are added to the main image or the background image, the amount of ink discharged per unit area is changed. Thus, the dot generation rate table (duty limit value) may be adjusted according to the printing methods.
Although the printer 1 for repeating the operation for forming the image while moving the heads 41 in the movement direction and the operation for transporting the medium in the transport direction is described in the above embodiments, the invention is not limited thereto. For example, a printer for forming an image through a continuous medium under a plurality of fixed heads or a printer for alternately repeating the operation for forming the image with respect to a continuous sheet transported to a printing area while moving a head along a transport direction of the continuous sheet and the operation for moving the head in a paper width direction intersecting the transport direction so as to form the image and, thereafter, transporting the medium portion, on which the image is not printed, to a printing area may be used.
As a method of discharging inks from nozzles, a piezoelectric method of applying a voltage to driving elements (piezoelectric elements) and expanding and contracting ink chambers so as to discharge inks may be used or a thermal method of generating air bubbles in nozzles using a heating element and discharging inks by the air bubbles may be used.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-254267 | Nov 2009 | JP | national |
| 2010-088909 | Apr 2010 | JP | national |
This application is a divisional of U.S. patent application Ser. No. 12/939,946, filed Nov. 4, 2010, which claims the priority to Japanese Patent Application Nos. 2009-254267, filed Nov. 5, 2009 and 2010-088909, filed Apr. 7, 2010 are expressly incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12939946 | Nov 2010 | US |
| Child | 14462149 | US |
