Patent Application
20100328388
1. Field of the Invention
The present invention relates to an inkjet type printer which uses a print head that ejects ink and treatment liquid, the print head scanning a predetermined area of a print medium a plurality of times to form an image within the predetermined area.
2. Description of the Related Art
Recently inkjet printers have been widely used from office applications such as photos, posters and CAD drawings to public exhibition applications or commercial print applications as a result of high-resolution and speeding-up of a print image. A print medium used for such various applications includes various types of mediums from inexpensive plain paper to expensive graphic glossy paper, and as to the image, there is a demand of increasing image quality such as high-resolution or high coloring performance or a demand of increasing image robustness such as water resistance or highlighter blur resistance.
A color print in the inkjet printer expresses various colors by ejecting color ink such as yellow, cyan and magenta onto the same pixel of the print medium. Since the plural colors of ink are ejected onto the print medium substantially simultaneously, it is necessary to use a fine coating paper or coating paper of which absorption characteristics are adjusted to be improved by applying special treatment on a surface of the print medium for meeting the above demand. In using a non-coating paper such as inexpensive plain paper, however, ink having relatively high permeability is required to be used.
For example, in a case of performing a color print on a plain paper, ink having high permeability is used for each color ink. However, the ink having the high permeability is low in edge sharpness expressing a blur degree of a boundary between print portions and an optical density value (OD value) thereof tends to be lowered. In a case of performing a print only in black color such as characters, since a contour of the character is blurred and coloring of the black color becomes unclear in the ink having the high permeability, print quality of the character is degraded as compared to ink having low permeability. For solving this problem, some of conventional technologies adopt a method in which a treatment liquid reacting with ink is applied on a print medium without use of the ink with the high permeability. According to this method, the treatment liquid reacting with ink is applied on the print medium before applying ink containing a color material thereon, and as a result of reaction between the ink and the treatment liquid, fixation performance of the ink in the print medium is enhanced.
Japanese Patent Laid-Open No. H11-268260 (1999), as a method of thus using the treatment liquid, discloses a technology in which two print heads for treatment liquid are arranged in both sides of a print head for color ink. In addition, Japanese Patent Laid-Open No. H08-281933 (1996) discloses a system of sandwiching treatment liquid dots with ink dots.
In the system disclosed in Japanese Patent Laid-Open No. H11-268260 (1999), the print head for treatment liquid to be used is selected corresponding to the scan direction of the print head performing a reciprocal scanning operation in such a manner that the treatment liquid is applied on the print medium before applying the color ink thereon. According to this system, in both of the forward scanning operation and the backward scanning operation of the print head, it is possible to apply the treatment liquid on the print medium before applying the color ink thereon. Therefore, as compared to a one-way print in which the print head for treatment liquid is provided only at one side of the print head for color ink and the print can be performed only in the direction where the print head for treatment liquid always goes ahead, the speeding-up of the print can be carried out. However, since the apparatus disclosed in Japanese Patent Laid-Open No. H11-268260 (1999) needs use of the two print heads for treatment liquid, it creates a possibility of leading to an increase in size and cost of the apparatus.
On the other hand, as shown in Japanese Patent Laid-Open No. H08-281933 (1996), according to the system of sandwiching the treatment dots with the ink dots, after performing a print in color ink, the treatment liquid is applied at least one time to an area where the color ink is printed and a print is performed in color ink once again to the area where the treatment liquid has been applied. In this system, since the print direction is limited to one way, it is possible to achieve the speeding-up. Further, by dispersedly arranging a pixel where the ink dot overlaps on the treatment liquid and a pixel where the treatment liquid dot overlaps on the ink dot, it reduces a problem that the color unevenness due to a difference in coloring characteristic between both the pixels adversely affects an image.
The technology disclosed in Japanese Patent Laid-Open No. H08-281933 (1996) described above is designed to macroscopically improve a difference in coloring between both the pixels due to a difference in the overlap order of the treatment liquid dot and the ink dot, by the arrangement of each of the dots. However, in the printing system of Japanese Patent Laid-Open No. H08-281933 (1996), since the treatment liquid is ejected from nozzles of the print head only at an initial scan, the nozzles used for ejecting the treatment liquid become primarily those in a particular range. Therefore, durability of the print head for treatment liquid is possibly damaged.
An object of the present invention is to provide a printer which can perform ejection of a treatment liquid at a scan before a scan at which ink is first ejected.
For achieving the above object, the present invention has the following configuration.
Specifically, according to a first aspect of the present invention, the present invention provides an inkjet printer in which a print head ejecting ink and a treatment liquid is used, the print head scans a unit area on the print medium by plural times, the ink is ejected to the unit area based upon ink ejection data and the treatment liquid is ejected to the unit area based upon the treatment liquid ejection data, thus performing formation of an image, the inkjet printer comprising: a treatment liquid ejection data generating unit configured to generate the treatment liquid ejection data for ejecting the treatment liquid from the print head to the unit area before the formation of the image by the ink starts; wherein the treatment liquid ejection data generating unit generates the treatment liquid ejection data in such a manner as to eject the treatment liquid at the plural times of the scans of the print head.
According to a second aspect of the invention, the present invention provides an inkjet printing method that a print head ejecting ink and a treatment liquid is used, the print head scans a unit area on the print medium by plural times, the ink is ejected to the unit area based upon ink ejection data and the treatment liquid is ejected to the unit area based upon the treatment liquid ejection data, thus performing formation of an image, the inkjet printing method comprising: a treatment liquid ejection data generating step of generating the treatment liquid ejection data for ejecting the treatment liquid from the print head to the unit area before the formation of the image by the ink starts, wherein the treatment liquid ejection data generating step generates the treatment liquid ejection data in such a manner as to eject the treatment liquid at the plural times of the scans of the print head.
The present invention can generate the ejection data for ejecting the treatment liquid based upon the ejection data of the ink, at the scan before the scan at which the ink is first ejected.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).
Hereinafter, embodiments of the present invention will be explained.
In the present specification, “ink” denotes a liquid containing a color material for applying a black color and other colors on a print medium. In addition, “treatment liquid” is a liquid which gets in contact with ink to act on the ink and denotes a liquid (image-performance improving liquid) for improving image performance such as image quality or image robustness, and further includes a liquid containing a component having a function for insoluble or cohesion of color materials in the ink. Here, “improvement on image robustness” unit to improve at least one of a water resistance, an alkali resistance, a highlighter-blur resistance and fixation properties of a printed image for improving robustness of a color ink image. On the other hand, “improvement on image quality” unit to improve at least one of coloring (density) and character sharpness of the printed image for improving quality of the color ink image.
Hereinafter, with reference to the drawings, preferred embodiments of the present embodiments will be explained in detail.
Compositions of color ink and treatment liquid used in the present embodiment will be explained.
(1) Production of Treatment Liquid
A treatment liquid was produced by mixing and dissolving the following components, thereafter was pressurized and filtered through a membrane filter (Trade name: Fluoro pore filter made by Sumitomo Electric Industries Co., Ltd.) having a pore size of 0.22 μm, and then pH thereof was adjusted to 9.8 with NaOH.
(2) Production of Color Ink (Dye Ink)
Ink of each color of yellow, magenta, cyan and black was produced by mixing the following components, and further pressurized and filtered through a membrane filter (Trade name: Fluoro pore filter made by Sumitomo Electric Industries Co., Ltd.) having a pore size of 0.22 μm to be adjusted.
This ink has the same composition as the yellow ink other than a point of replacing the dye for C.I. acid red 289; 2.5 parts.
This ink has the same composition as the yellow ink other than a point of replacing the dye for C.I. acid blue 9; 2.5 parts.
This ink has the same composition as the yellow ink other than a point of replacing the dye for C.I. food black 2; 3 parts.
It should be noted that upon carrying out the present invention, the ink to be used is not limited particularly to the dye ink, pigment ink where pigment is dispersed may be used, and the treatment liquid to be used may adopt a liquid causing cohesion of the pigment.
As examples of the pigment ink causing the cohesion by mixing with the above treatment liquid, the following may be included.
(3) Production of Color Ink (Pigment Ink)
An anionic polymer P-1 (stylene-methacrylic acid-ethylacrylate, an acid number 400, a weight-average molecular weight 6.000, solution of solid contents of 20%, and a neutralizing agent: potassium hydroxide) was used as a dispersant. This dispersant and the following materials were put into a batch type vertical sand mill (made by Imex Co., Ltd.), where glass beams each having a diameter of 1 mm were filled as media and the dispersing processing was executed for three hours in water-cooling. A viscosity after the dispersing was 9 cps and pH thereof was 10.0. Bulky particles in the dispersing liquid were removed by a centrifugal machine to produce a carbon black dispersant having a weight-average particle diameter of 100 nm.
Next, black ink K2 for inkjet containing pigment was obtained by sufficiently dispersing the above obtained dispersant. The solid contents of the final preparation were about 10%.
An anionic polymer P-2 (stylene-acrylic acid-methylmethacrylate, an acid number 280, a weight-average molecular weight 11.000, solution of solid contents of 20%, and a neutralizing agent: diethanol amine) was used as a dispersant. This dispersant and the following materials were used to execute the dispersing processing in the same way with the production of black ink, producing a yellow color dispersing element having a weight-average particle diameter of 103 nm.
(Trade name: NOVAPERM YELLOW PH-G made by Hoechst Aktiengesellschaft)
Yellow ink K2 for inkjet containing pigment was obtained by sufficiently dispersing the above obtained yellow dispersing element. The solid contents of the final preparation were about 10%.
An anionic polymer P-1 used in producing the black ink was used as a dispersant. This dispersant and the following materials were used to execute the same dispersing processing as in a case of the carbon black dispersing element, producing a cyan color dispersing element having a weight-average particle diameter of 120 nm.
Cyan ink for inkjet containing pigment was obtained by sufficiently stirring the above obtained cyan color dispersing element. The solid contents of the final preparation were about 9.6%.
An anionic polymer P-1 used in producing the black ink was used as a dispersant. This dispersant and the following materials were used to execute the same dispersing processing as in a case of the carbon black dispersing element, producing a magenta color dispersing element having a weight-average particle diameter of 115 nm.
Magenta ink for inkjet containing pigment was obtained by sufficiently dispersing the above obtained magenta color dispersing element. The solid contents of the final preparation were about 9.2%.
According to the present invention, the treatment liquid and the color ink as mentioned above are mixed on the print medium or at a position where they are permeated into the print medium. As a result, the cationic component contained in the treatment liquid and the anionic component used in the color ink react with each other. Therefore, the color materials of the ink can be insoluble or cohesive to improve image performance such as image robustness or image quality.
Next, an configuration of an entire inkjet printer in the present embodiment will be explained.
In addition, the inkjet printer in the present embodiment is provided with caps 20 each covering the ejection opening face of the print head. Here, the caps 20 include five caps 20K, 20C, 20M, 20Y and 20H for covering the respective ink ejection faces of the five print heads. The print head 22 and the ink tank 21 return back to a home position where the cap 20 is present and stand by therein.
It should be noted that in a case of referring to these print heads, ink tanks and caps individually, a reference number attached to each of them is used and in a case of referring to them collectively, as a collective reference number, numeral 22 is used to the print head, numeral 21 is used to the ink tank, and numeral 20 is used to the cap.
In the present example, the print head and the ink tank constitute a head cartridge such that they are integrally or separately formed, and the head cartridge is detachably mounted in a carriage (not shown). The print head and the ink tank may be separately mounted in the carriage without constituting the head cartridge. The carriage is guided along a main scan direction of an arrow X to be movable and is moved reciprocally in a main scan direction through the belt 4 by the carriage motor 2. The print medium 1 is conveyed in a sub scan direction (arrow Y direction) crossing (in a case of the present example, orthogonal) to the main scan direction by the carriage roller.
A print operation in the printer arranged as above will be explained with reference to the
On one hand, the color ink and the treatment liquid are supplied to the print head 22 from the ink tank 21. The print head 22 performs a print on the plain paper as a print medium corresponding to binary image data while moving in an arrow X1 direction (forward scan direction) and X2 direction (backward scan direction) in
A host computer (image input unit) 28 inputs multi-valued image data stored in various memory mediums such as a hard disc to an image processing unit 29 in an inkjet printer 301. The multi-valued image data can be received also from an image input device such as a scanner or a digital camera connected to the host computer 28. The image processing unit 29 executes image processing, which will be described later, to the multi-valued image data inputted from the image input unit 28 to be converted into binary image data. This data conversion generates the binary image data (color ink ejection data) for ejecting plural kinds of color ink from the print head. The binary image data (treatment liquid ejection data) for ejecting the treatment liquid also are herein generated. Therefore, the image processing unit 29 serves as ink ejection data generating unit and treatment liquid ejection generating unit. An image output unit 30 applies the color ink and the treatment liquid based upon the binary image data of the color ink and the treatment liquid converted in the image processing unit 29 to perform an image formation.
An image output unit 30 itself is controlled according to the program printed in a ROM 304 by a MPU (Micro Processor Unit) 302. A RAM 305 is used as an operation area of the MPU 302 or a temporal data storage area. The MPU 302 performs through an ASIC 303 control of a drive system 308 of the carriage, a conveyance drive system 309 of the print medium, a recovery drive system 310 of the print head and a drive system 311 of the print head. In addition, the MPU 302 is configured to be readable to a print buffer readable from the ASIC 303.
The print buffer 306 temporarily stores image data converted into a format transferable to the print head. A mask buffer 307 temporarily stores a predetermined pattern for executing AND processing to the data transferred from the print buffer 306 to the print head as needed. It should be noted that plural sets of mask patterns for a multi-path print of different path numbers are prepared in the ROM 304 and at an actual print, the corresponding pattern is read out from the ROM 304 and is stored in the mask buffer 307.
Next, a print operation in the present embodiment will be explained. The present embodiment adopts a multi-pass printing system in which plural times of reciprocal scans are performed in a predetermined area to apply ink and treatment liquids. Here, the print scan is performed by five times of the reciprocal scans. In addition, in the following explanation, for simple explanation, the kinds of ink used for printing an image are composed only of cyan (cy) ink and magenta (M) ink.
In the print heads 22Cy and 22M, 1024 pieces of the ejection openings within a range α (refer to
First, in a first scan, a treatment liquid is ejected from the ejection openings in the area of the print head 22H based upon ejection data of the treatment liquid at the first scan in the print area 50-1.
Next, the print medium 1 is conveyed in a sub scan direction (Y direction) by a length of ⅕ of the print head. It should be noted that in
Thereafter, in a second scan, ink is ejected from the ejection openings in the area B of the print heads 22Cy and 22M based upon ejection data of the ink at the second scan in the print area 50-1. In addition, the treatment liquid is ejected from the ejection openings in the area b of the print head 22H based upon ejection data of the treatment liquid at the second scan. At the second scan, a first scan to the print area 50-2 is performed at the same time and the treatment liquid is ejected from the ejection openings in the a area of the print head 22H.
Next, the print medium 1 is conveyed in the sub scan direction by a length of ⅕ of the print head. Thereafter, in a third scan, the ink is ejected from the ejection openings in the C area of the print heads 22Cy and 22M based upon ejection data of the ink liquid at the third scan in the print area 50-1. In addition, the treatment liquid is ejected from the ejection openings in the area c of the print head 22H based upon ejection data of the treatment liquid at the third scan. Further, at the third scan, a second scan to the print area 50-2 and a first scan to the print area 50-3 are performed to eject the ink from the ejection openings in the areas B, b and a of the print heads 22Cy, 22M and 22H.
Next, the print medium 1 is conveyed in the sub scan direction by a length of ⅕ of the print head. Thereafter, in a fourth scan, the ink is ejected from the ejection openings in the area D of the print heads 22Cy and 22M based upon ejection data of the ink at the fourth scan in the print area 50-1. In addition, the treatment liquid is ejected from the ejection openings in the area d of the print head 22H based upon ejection data of the treatment liquid at the fourth scan. Further, at the fourth scan, a third scan to the print area 50-2, a second scan to the print area 50-3 and a first scan to the print area 50-4 are performed. During the first scan, the ink and the treatment liquid are ejected from the ejection openings in each of the areas C, c, B, b and a of the print heads 22Cy, 22M and 22H. The application of the treatment liquid to the print area 50-1 is completed by the first scan to the fourth scan.
Next, the print medium 1 is conveyed in the sub scan direction by a length of ⅕ of the print head. Thereafter, in a fifth scan, the ink is ejected from the ejection openings in the area E of the print heads 22C and 22M based upon ejection data of the ink at the fifth scan in the print area 50-1. At the fifth scan, a fourth scan to the print area 50-2, a third scan to the print area 50-3, a second scan to the print area 50-4 and a first scan to the print area 50-5 are performed. During this period, the ink and the treatment liquid are ejected from the ejection openings in each of the areas D, d, C, c, B, b and a of the print heads 22Cy, 22M and 22H.
The print of the image by the ink to the print area 50-1 is completed by the second scan to the fifth scan.
Hereinafter, by repeating the similar scan, the print of the image and the application of the treatment liquid on the print areas 50-2, 50-3, 50-4 and 50-5 are sequentially completed. The application of the treatment liquid is performed based upon the ejection data generated by the characteristic processing which will be explained below.
Next, the aforementioned characteristic processing in the present embodiment will be explained with reference to
There will be, as described above, explained the ejection data of the treatment liquid generated based upon the binary bit map data (Cy and M data) in the cyan ink and magenta ink developed by the binarization unit 31 in
First, the data generating unit 33 (refer to
In
In this way, it is determined in one pixel unit (each unit area) what scan number the scan starting the image formation (hereinafter, print start scan) corresponds to. That is, the scan number (from 2 to 5) at an image forming start is determined based upon the data in
The above processing is the processing content in the data generating unit 33 for treatment liquid.
Next, AND of the pattern in
By thus generating the ejection data of the treatment liquid for each scan, as described later, it is possible to eject the treatment liquid by a scan immediately before the color ink is ejected. In addition, in the print head 22H for treatment liquid, it can be prevented that the ejection openings to be used become primarily those in a particular range. It should be noted that a method of generating the ejection data of the treatment liquid from the ejection data of each ink color and a method of distributing the ejection data of the treatment liquid to each scan are not limited to the aforementioned method.
In the present embodiment, as described above, in the plural times of the scans for forming the image, it is detected for each one pixel what scan number the scan at which the ink is first applied corresponds to. That is, the order of the scan for starting the image formation (print start scan) is detected for each one pixel, and the treatment liquid is ejected at a scan before the detected scan. In consequence, the liquid first ejected to each pixel is the treatment liquid and in a position where the treatment liquid is permeated on or into the print medium, the treatment liquid is mixed and reacts with the color ink ejected at a scan immediately after the scan at which the treatment liquid is applied. As a result, the color material of the ink can be insoluble or cohesive to improve image performance such as image robustness and image quality. In addition, since the treatment liquid is always applied at the scan immediately before the ink is applied, the time interval from a point where the treatment liquid is applied to a point where the ink is applied can be substantially uniformed. Therefore, the ink can appropriately react with the treatment liquid simply by applying the treatment liquid in a location only where the ink is applied, without application of a large number of treatment liquids to obtain a uniform image performance improvement effect in an entire image to be printed. That is, in an image to be printed, generation of the color unevenness, the bleeding, the beading, the drying defect and the like can be reduced.
In addition, since it is possible to prevent the ejection openings used in the print head 21H from becoming primarily those in a particular range by dispersing the ejection of the treatment liquid to the plural times of the scans, durability of the nozzle can be improved. On the other hand, in the conventional multi-pass print, the ejection timing of the treat liquid is determined as an initial scan time (first scan time) only. In this case, for example, in
Next, a second embodiment in the present invention will be explained with reference to
The second embodiment also, in the same way with the first embodiment, adopts a multi-pass printing system in which the nozzle line of the print head is equally divided into five ejection opening groups and five times of scans are performed to each scan area using the different ejection opening groups to complete an image formation. The second embodiment uses a mask pattern for dividing the ejection data of each color ink into plural times of scans to in advance prepare a mask pattern in such a manner that application of the treatment liquid is made before ejection of the ink, and the treatment liquid is ejected only in twice scans of the initial scan and the next scan. The second embodiment differs in this respect from the first embodiment.
Hereinafter, a printing method in the second embodiment will be explained, but ink used for formation of an image is explained as cyan (Cy) and magenta (M) only in the same way with the first embodiment.
As described before, the image data of Cy and M ink (Cy data and M data) are binarized by the binarization unit 31 in
First, the Cy data and the M data are separated into data for each of a second scan to a fifth scan. For example, the Cy data and the M data in the second, third, fourth and fifth scans performed in the print area 50-1 correspond to the areas B, C, D and E of the print heads 22Cy and 22M. In the same way with the aforementioned first embodiment, the Cy data are separated as shown from
A mask pattern M1 (second mask pattern) in
Now, as shown in
Next, ejection data of the treatment liquid shown in
As shown in
It should be noted that a method of generating the ejection data of the treatment liquid from the mask pattern for generating the ejection data of each ink is not limited to the aforementioned method only.
In this way, in the second embodiment, the mask patterns for treatment liquid for ejecting the treatment liquid are in advance prepared at two separate scans composed of the initial scan and the next scan based upon the mask pattern used for the image formation by the color ink. Therefore, the ejection pattern of the treatment liquid at each scan, that is, an arrangement pattern of dots formed by the treatment liquid can be in advance determined. As a result, the control for printing can be simplified to short the time required for the control.
Further, the second embodiment is configured such that the treatment liquid is applied at the scan (first scan) immediately before the second scan where ink is ejected and at the second scan corresponding to the application of ink by the third, fourth and fifth scans where the ink is ejected. In consequence, in regard to the ink ejected at each scan after the second scan, a difference in the time interval from a point where the treatment liquid is applied to a point where the ink is applied is generated. However, as compared to a case where the treatment liquid is applied by the one initial scan only as conventional, the present embodiment where the treatment liquid is applied at the initial scan and the second scan separately can reduce the difference in the time interval from a point where the treatment liquid is applied to a point where the ink is applied is generated. Therefore, the effect by the treatment liquid can be largely increased as compared to the conventional technology, thus obtaining an image with high quality.
Next, a third embodiment of the present invention will be explained with reference to
On the other hand, in a case where the data amount at the first scan where only the treatment liquid is ejected is smaller than the predetermined threshold value, the ejection data of the color ink in each color and the ejection data of the treatment liquid are sent to changing unit 37. For example, in a case where the ejection data of the treatment liquid does not exist over an entire area of one page of the print medium at the first scan, the ejection data of the color ink in each color and the ejection data of the treatment liquid are sent to the changing unit 37. This is a case where there does not exist the data for ejecting the treatment liquid from the ejection openings in the a area over an entire area of one page of the print medium. Alternatively, in a case where the data amount of the ejection data is less than the threshold value, the ejection data of the treatment liquid at the first scan may be added to the ejection data of the treatment liquid at the next scan.
The changing unit 37 changes the above-mentioned print operation to the second print operation to be described later. The second print operation is a printing method of forming an image by four times of scans alone. In the second print operation, the first scan in the above-mentioned print operation, that is, the scan of ejecting the treatment liquid only does not exist. Therefore, the ejection data of the treatment liquid at the first scan is not necessary and therefore is eliminated. In this way, the changing unit 37 eliminates the ejection data of the treatment liquid at the first scan and generates the ejection data of the color ink in each color and the treatment liquid for performing the second print operation (performing image formation by four times of scans).
First, in a first scan, based upon ejection data at the first scan to the print area 60-1, ink is ejected from the ejection openings in the A area of the print heads 22C and 22M and a treatment liquid is ejected from the ejection openings in the a area of the print head 22H. Next, the print medium 1 is conveyed in a sub scan direction (arrow Y direction) by a length of ¼ of the print head. Thereafter, in a second scan, based upon ejection data at the second scan to the print area 60-1, ink is ejected from the ejection openings in the B area of the print heads 22C and 22M and a treatment liquid is ejected from the ejection openings in the b area of the print head 22H. At this second scan, the first scan is performed to the print area 60-2.
Next, the print medium 1 is conveyed in a sub scan direction by a length of ¼ of the print head. Thereafter, in a third scan, based upon ejection data at the third scan to the print area 60-1, ink is ejected from the ejection openings in the C area of the print heads 22C and 22M and a treatment liquid is ejected from the ejection openings in the c area of the print head 22H. At this third scan, the second scan is performed to the print area 60-2 and the first scan is performed to the print area 60-3. The application of the treatment liquid to the print area 60-1 is completed by the first scan to the third scan. Next, the print medium 1 is conveyed in a sub scan direction by a length of ¼ of the print head. Thereafter, in a fourth scan, based upon ejection data at the fourth scan to the print area 60-1, ink is ejected from the ejection openings in the D area of the print heads 22C and 22M. At this fourth scan, the third scan is performed to the print area 60-2, the second scan is performed to the print area 60-3 and the first scan is performed to the print area 60-9. The print of the image of the ink to the print area 60-1 is thus completed by the first scan to the fourth scan. Hereinafter, by repeating the similar scans, the print of the image and the application of the treatment liquid to the print areas 60-2, 60-3 and so on will be sequentially completed.
The above respective embodiments have explained an example where the ejection opening of the print head for ejecting the ink and the ejection opening of the print head for ejecting the treatment liquid are arranged to be at the same position in the direction (for example, sub scan direction) crossing to the main scan direction. However, it may be possible to use the print head in which the ejection opening for ejecting the ink and the ejection opening for ejecting the treatment liquid are arranged to be shifted in the direction (for example, sub scan direction) crossing to the main scan direction. In addition, the present invention may be applied to a case where the number of the ejection openings for treatment liquid is greater than the number of the ejection openings for color ink and the ejection opening array for treatment liquid is longer than the ejection opening array for ink. Further, the present invention may be applied to a case where the ejection opening array for ink is longer than the ejection opening array for treatment liquid.
The first embodiment shows a case where the ejection timing of the treatment liquid is divided into each timings of the first scan, the second scan, the third scan and the fourth scan. In the second embodiment, the ejection timing of the treatment liquid is divided into each timings of the initial scan (first scan) and the next scan (second scan). In a unit area of one pixel, plural pixels or the like, the treatment liquid may be ejected in the unit area where an image formation starts to be made, before the image formation by ink starts to be made. Accordingly the division number or the division method in the ejection timing of the treatment liquid is not limited to the aforementioned embodiments. For example, the treatment liquid may be ejected separately at the initial scan (first scan) and the subsequent third scan. Further, the treatment liquid is not necessarily ejected before image formation in regard to all the unit areas constituting the image, and in regard to a part of all the unit areas, the treatment liquid may be ejected after the image formation starts to be made.
In addition, the first embodiment and the second embodiment are configured such that the treatment liquid is not ejected in regard to the pixels (margin part) where the ejection data of ink are not present. However, in a case where the treatment liquid is ejected also in regard to the pixels where the ejection data of color ink are not present (margin part), the effect of improving an image quality such as a blur or a feathering phenomenon can be obtained to the ink adjacent to the ejected treatment liquid. Therefore, in regard to the pixels (margin part) where the ejection data of the ink are not present, presence/absence of the treatment liquid application or the division number and the division method of the ejection timing are not limited.
In each of the above embodiments, the treatment liquid is ejected at the scan before the scan at which the image formation by the ink starts. However, as long as the treatment liquid is ejected before the image formation by the ink starts, the treatment liquid may be ejected at the same scan for starting the image formation. In this case, since the print head used in the aforementioned embodiment (
The present invention may be widely applied to various inkjet printers where formation of an image by color ink and application of a treatment liquid are preformed in a unit area on a print medium by plural times of scans of the print head capable of ejecting the ink and the treatment liquid. Accordingly the configuration and the arrangement number of the print head are not limited to the aforementioned embodiments only.
In addition, the present invention may eject the treatment liquid at the scan before ejecting the ink to the unit area, wherein the scan number in ejecting the treatment liquid may be set as needed.
Further, in the above first embodiment, the treatment liquid is applied at the scan (earlier scan by one scan) immediately before the scan where the ink is ejected. In the second embodiment, the treatment liquid is applied at the scan (first scan) immediately before the scan where the ink is ejected and at the second scan corresponding to the application of the ink by the third, fourth and fifth scans where the ink is ejected. However, it is possible to determine as needed by what scan number the treatment liquid is applied at the earlier scan than the scan where the ink is applied, based upon permeation characteristics (permeation time) of the treatment liquid into the print head. In addition, the print head may eject one kind of ink as ink for forming an image.
In addition, the unit area is not limited to the area corresponding to the dot formed on the print medium by ink and another area may be set.
In the aforementioned embodiment, in addition to the color ink used for image formation, the treatment liquid for improving the image performance by the color ink is prepared separately for application. Therefore, since the treatment liquid itself is not used for forming the image, it is preferably close to a colorless and transparent liquid. Even if the colored liquid is used, the component thereof for improving the image performance is added to a part or all of light ink such as light cyan ink, light magenta ink and light gray ink, so that the colored ink may act as having both functions of image formation and an increase in image performance. In this case, since it is not necessary to provide the ink tank and the print head for treatment liquid, elimination in the number of components is possible, contributing greatly to a decrease in size and low costs of the apparatus. Further, a part or all of deep color ink of the color ink used for image formation may act as the treatment liquid.
The aforementioned embodiment explains the configuration where the image processing unit 29 executing the characteristic processing of the present invention is provided in the inkjet printer, but the image processing unit 29 is not necessarily provided in the inkjet printer. For example, as shown in
The feature of the present invention is the data processing executed in the image processing unit 29. In consequence, the data generating apparatus provided with the image processing unit 29 executing the characteristic data processing of the present invention is also in the scope of the present invention. In a case where the image processing unit 29 is provided in the inkjet printer, the inkjet printer acts as the data generating apparatus of the present invention, and in a case where the image processing unit 29 is provided in the host computer, the host computer acts as the data generating apparatus of the present invention.
Further, a computer program executing the above characteristic data processing by a computer or a print medium storing the program to be readable by a computer is also in the scope of the present invention.
In addition, the present invention may be applied to various types of printers using a print medium such as paper, cloth, non-woven cloth or OHP film, and examples of a specific application apparatus may include an office machine such as a printer, a copier or a facsimile, and a mass-production machine.
Aspects of the present invention can also be realized by a computer of a system or apparatus (or devices such as a CPU or MPU) that reads out and executes a program recorded on a memory device to perform the functions of the above-described embodiment (s), and by a method, the steps of which are performed by a computer of a system or apparatus by, for example, reading out and executing a program recorded on a memory device to perform the functions of the above-described embodiment(s). For this purpose, the program is provided to the computer for example via a network or from a recording medium of various types serving as the memory device (e.g., computer-readable medium).
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2009-151072, filed Jun. 25, 2009, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-151072 | Jun 2009 | JP | national |
