JP2004330624A - Inkjet recording head and method of inkjet color recording using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a desired image by printing an image by a dye ink in one of an inward path and an outward path or an image by a pigment ink in the other path and to obtain a color image by using both of dye and pigment inks in the bidirectional printing at a high speed. <P>SOLUTION: Nozzles of C, M, and Y of dye inks are provided on one substrate in the above order to form one group and nozzles of PY, PM, and PC of pigment inks are provided on the identical substrate in the above order to form one group. An image is formed in the unidirectional printing by each of groups of the inks so as to form the image in the order of yellow, magenta and cyan. When both of the dye inks and the pigment inks are used, the bidirectional printing is performed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid ejection recording head that applies a plurality of different types of liquids such as inks of a plurality of colors to a recording medium such as paper, and in particular, prints with a dye ink, prints with a pigment ink, or prints both simultaneously. To a liquid recording head.
[0002]
[Prior art]
2. Description of the Related Art In a printing apparatus, particularly an ink jet printing apparatus, recording with dye ink, pigment ink, and the like has recently been performed in color printing. Dye inks have been commercialized early on due to the fact that the colorant dissolves in the liquid that is the main component of the ink in the ink jet recording device, so that the nozzles of the recording device are unlikely to be clogged and that the color is excellent on the recording medium. Have been. However, there is a disadvantage that fading occurs in a relatively short time due to light, ozone, or the like. In recent years, with the remarkable progress of the ink jet recording technology, the image quality has become comparable to that of so-called silver halide photography. On the other hand, with the progress of pigment dispersion technology, application of pigment ink to ink jet technology has begun and problems such as clogging are being solved. A pigment ink has a significantly longer resistance to light, ozone, and the like, and a period of time until the color is faded is much longer than a dye. Therefore, the image fastness is excellent. However, in terms of color development, there is a drawback that the color is more vivid than the dye. However, recent advances in microdrop formation technology have made it possible to form an image quality that can be considered almost the same as a photograph. Whether the image of the dye or the image of the pigment is good can be said to have advanced so much as to be a matter of preference. In terms of storability, pigment inks are overwhelmingly superior, but it is undeniable that dye inks are superior in terms of image quality. There is a debate about whether it can't be called a photograph if it is not beautiful, or if it cannot be preserved, it cannot be called a photograph. It is considered that this choice should be left to the user's choice rather than the purpose of use of the image. However, most of the printing apparatuses so far have used inks using dyes. However, in recent years, printing apparatuses capable of mounting pigment ink have also been released. However, these printing apparatuses are dedicated printing apparatuses, and the only way to realize both of them in one apparatus is to exchange ink cartridges or heads. Further, in recent years, a printing apparatus for printing by simultaneously mounting a pigment ink and a dye ink has been commercialized. However, the purpose of these products is to print characters in black, and color printing of so-called image information other than characters is performed by dyes. Further, various devices have been devised in order to clearly compare these black characters and images. There are many such as JP-A-11-1647. Japanese Patent Application Laid-Open No. 2001-63029 and the like have also devised a technique for printing a dye ink and a pigment ink. However, in this head, the color arrangement order of the nozzles is the same for both inks, and no consideration is given to reciprocal printing.
[0003]
[Means for Solving the Problems]
In view of such circumstances, the present invention has been devised so that a user can select and use a dye ink and a pigment ink, and furthermore, when either of them is acceptable, the printing time can be reduced by using both inks. Is realized. In order to solve the above-mentioned problem, a liquid discharge recording head according to the present invention scans a recording medium in two directions while sequentially arranging yellow and magenta from three discharge port arrays arranged in a direction different from the scanning direction. A first ejection port array group for ejecting a liquid containing a cyan colorant, and a second ejection port array of each color arranged on the same substrate in line symmetry with respect to the ejection port array group and the ejection port array. A head composed of a group of ejection port arrays, wherein the colorant of the ink in one group of ejection port rows comprises a dye, and the colorant of the ink in the other group of ejection port rows comprises a pigment. When printing in one direction only, an image with good color development using only dye ink is printed, and when scanning in the opposite direction, printing with only pigment ink is performed to print a highly robust image. If robustness and good color development are not required, bi-directional printing enables high-speed printing using half the amount of dye ink and pigment ink. An image having better fastness than an image using only the dye ink can be obtained.
[0004]
Further, for example, an ejection port array or an ejection port array group for ejecting black ink may be provided separately from the first and second ejection port array groups.
[0005]
Silicon is desirable as the substrate having the energy generating element group, and when forming a through hole for supplying a liquid by anisotropic etching, the plane orientation may be <100> or <110>. More desirable. Further, since the orifice plate is formed of a photosensitive epoxy resin, the above-described high-density ejection port array group can be formed easily with high precision.
[0006]
In the present specification, the “recording medium” means not only paper used in a general printing apparatus, but also broadly, a cloth, a plastic film, a metal plate, and the like that can accept ink. .
[0007]
In addition, “ink” means a liquid that can be applied to a print medium to form an image, a pattern, a pattern, or the like or to process the print medium. Further, the “pixel area” means a minimum area that expresses a primary color or a secondary color by applying one or a plurality of inks, and includes not only pixels but also superpixels and subpixels. Further, the number of scans required to complete the pixel region is not limited to one, but may be a plurality of times. Further, the “process color” means a color formed by mixing three or more inks on a print medium, including secondary colors.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0009]
(1st Embodiment)
FIGS. 1A and 1B are explanatory diagrams schematically showing a main part of a recording head according to a first embodiment of the present invention, in which FIG. 1A is a schematic diagram viewed from above, and FIG. (C) is a cross-sectional view. As shown in FIG. 1C, the recording head 300 of the present embodiment includes a substrate 7 including a heat generating element 5 as an energy conversion element, and an orifice plate 6 forming the discharge port 1.
[0010]
In this embodiment, the substrate 7 is formed of a silicon single crystal having a plane orientation of <100>, and has a heat-generating resistor element 5 on a sparse upper surface (connection surface with the orifice plate 6) as shown in FIG. A drive circuit 3 including drive transistors for driving the heating resistor element, a contact pad 9 for connection to a wiring board described later, a wiring 8 for connecting the drive circuit 3 to the contact pad 9, and the like use a semiconductor process. It is formed. The substrate is provided with six through-holes formed by anisotropic etching in a region excluding the above-described drive circuit 3, the heating resistor element 5, the wiring 8, and the contact pad 9, and each of the through-holes will be described later. Ink supply ports 2 and 2a for supplying liquid to 21 to 23 and 31 to 33 are formed. FIG. 1A schematically shows a state in which a substantially transparent orifice plate 6 is placed on a substrate 7, and the above-described ink supply port is omitted.
[0011]
The orifice plate 6 provided on this substrate is formed of a photosensitive epoxy resin in this embodiment, and corresponds to the above-mentioned heating resistor element 5 by a process described in, for example, JP-A-62-264957. Thus, the discharge port 1 and the liquid flow path 10 are formed. Here, as described in Japanese Patent Application Laid-Open No. 9-11479, the above-described anisotropic etching is performed by forming a silicon oxide film or a silicon nitride film on a silicon substrate, and then forming a through-hole, a discharge port, and a liquid flow path. It is desirable to form an orifice plate provided with the above and remove the silicon oxide film or silicon nitride film at the ink supply port, since an inexpensive and precise ink jet head can be manufactured. In any case, all the ejection port arrays are arranged on the same substrate together with the respective ejection port groups, and are formed by the processes described above, so that the alignment accuracy can be extremely high.
[0012]
The recording head 300 having such a substrate 7 and the orifice plate 6 uses the pressure of bubbles generated by film boiling due to the heat energy applied by the electrothermal transducer 5 to discharge liquid such as ink from the discharge port 1. The recording is performed by discharging. As shown in FIG. 2A, the recording head 300 is fixed to the ink flow path forming member 12 communicating with the above-described ink supply port, and provided on the wiring board by connecting a contact pad to the wiring board 13. When the electrical connection unit 11 is connected to an electrical connection unit of a recording apparatus described later, a drive signal or the like can be received from the recording apparatus. FIG. 2B is a perspective view showing an example of a recording head cartridge 100 including the recording head 300 of the present invention. As shown in FIG. A tank holder 150 is provided for holding an ink tank 200 (200Y, 200M, 200C, 200PY, 200PM, 200PC) for supplying ink to the forming member. Here, Y, M, and C represent yellow ink, magenta ink, and cyan ink, respectively, in which the colorant is a dye, and PY, PM, and PC represent yellow ink, magenta ink, and cyan ink, respectively, in which the colorant is a pigment. I do.
[0013]
Here, in the recording head of the present embodiment, a plurality of ejection ports 1 are provided and arranged at a predetermined pitch to form ejection port arrays 21 to 23 and 31 to 33 substantially parallel to each other. ing. Here, in FIG. 1A, the i-th ejection port from the drawing of each of the ejection port arrays 21 to 23 coincides with the arrow direction shown in FIG. 1A. In this manner, the ejection port arrays 21 to 23 of the present embodiment are arranged such that the corresponding ejection ports coincide with the scanning direction when the recording head is mounted on a recording apparatus or the like to be described later and scanned. The first outlet port group 20 is formed. The ejection port arrays 31 to 33 are also arranged in the same manner as the ejection port arrays 21 to 23, and the second ejection port array group 30 is adjacent to the first ejection port group 20 by the ejection port arrays 31 to 33. Is formed.
[0014]
In the present embodiment, with respect to the six ejection port arrays of these two ejection port array groups, cyan (C, PC) is used for the outermost ejection port arrays 23 and 33, and magenta (M, PM) is used for the ejection port arrays 22 and 32. ), Yellow (Y, PY) is discharged from the innermost discharge port arrays 21 and 31 adjacent to each other. Therefore, the above-described ink supply ports 2a and 10a contain yellow ink, the two ink supply ports adjacent to the ink supply ports 2a and 10a contain magenta ink, and the two outermost ink supply ports contain cyan ink. Are supplied from the ink tanks 200Y, 200M, 200C, 200PY, 200PM, and 200PC, respectively.
[0015]
In the present embodiment, the size of one heating resistor 5 is 30 μm × 30 μm, the width of the ejection port, the driving circuit and the wiring (see a in FIG. 1A) is 1.2 mm, and the top surface of the substrate of the ink supply port 2 Is 0.2 mm (see b in FIG. 1C), and the substrate size can be 1.2 × 6 + 0.2 × 6 = 8.4 mm. Reducing the size of the substrate also has the advantage that the capacity of the memory for holding the transfer data of the recording head can also be reduced in proportion to the substrate size.
[0016]
Further, in the present embodiment, as is clear from FIGS. 1A and 1B, the first ejection port array group 20 and the second ejection port array group 30 are respectively formed by the respective ejection port groups. The ejection openings of the ejection opening arrays 21 to 23 and 31 to 33 are formed so as to be offset from each other in the arrangement direction of the ejection openings so as to complement each other in the above-described scanning direction. As shown in FIG. 1B, in the present embodiment, in each of the ejection port arrays forming the first ejection port row group and the second ejection port row group, 128 ejection ports have t1 = t2 = It is formed by forming rows at a pitch of about 40 μm (1/600 inch). The arrangement of the ejection port arrays 21 and 31 is exactly the same as the pitch of the ejection port array with respect to the sub-scanning direction of the print head (in this embodiment, the arrangement direction coincides with the arrangement direction of the ejection port arrays). (T3 = 1 / 2t1 = about 20 μm).
[0017]
Now, an image forming method using a head having such a nozzle arrangement will be described below. In the following example, it is assumed that the discharge amount of each nozzle is 8 pl, for example. One pixel is 600 pixels per inch in the scanning direction and 1/1200 inch in the main scanning direction again in the sub-scanning direction. When printing a single color (any of C, M, and Y), one pixel is used. On the other hand, one droplet is ejected. At this time, reciprocating printing is not performed, and the way of ink overlapping is always Y, M, C. Such overlapping of colors is the same as in normal printing. In this manner, an image can be formed using the dye inks C, M, and Y. Further, when the main scanning direction is reversed in this configuration and ink is ejected only from the second group of ejection opening arrays, an image is formed using only PC, PM, and PY inks. The printing in this case differs from the printing in C, M, and Y only in that the main scanning direction is reversed. Further, when bidirectional printing is performed in this configuration, an image can be formed by mixing the dye ink and the pigment ink by discharging the dye ink on the outward path and the pigment ink on the return path. In this case, it is not necessary to send the paper feed when printing the forward path and the return path. This is because the nozzle rows of the first group and the nozzle rows of the second group are out of alignment with each other by 1/1200 inch, and the row of discharge ports in each nozzle row is 1/600 inch. A high-resolution image can be formed at a high speed. In addition, the color development of the dye and the fastness of the pigment to light and ozone are improved. Any of these modes can be selected by a user on software existing in a host computer that controls a printing device called a so-called printer driver. For example, a button such as "clean", "long-lasting", or "fast" may be selected by clicking with a mouse. It is also possible to determine which of the three modes to use by default. Further, at this time, a method of correcting a color due to a difference in color in each mode can be adjusted so that the best color can be realized by providing a color table in each case in software. Of course, the same can be achieved by simply loading all the software inside the printing device and transferring the image data and information on which of the three modes to print from the host computer. In addition, as in recent years, the printing device directly reads image information recorded in a flash memory or the like by a digital camera, and selects which of a large number of images and which of the three modes to select, such as “clean”, “long-lasting”, The same can be realized by selecting by pressing a button such as "early".
[0018]
(Second embodiment)
3 and 4 are views showing a recording head according to a second embodiment of the present invention and a recording head cartridge on which the recording head is mounted. In the present embodiment, portions having the same functions as those in the above-described first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. FIGS. 3A and 3B are explanatory views schematically showing main parts of the recording head, where FIG. 3A is a schematic view seen from above, FIG. 3B is an explanatory view for explaining the arrangement of ejection ports, and FIG. It is. 4A is a perspective view showing the recording head shown in FIG. 3 fixed to the ink flow path forming member 12, and FIG. 4B is a perspective view of the recording head cartridge 100 provided with the recording head 300 of the present invention. FIG. 4C is a perspective view showing an example, and FIG. 4C is an explanatory diagram for explaining an ink tank removably mounted on the recording head cartridge.
[0019]
This embodiment is different from the first embodiment in that a silicon substrate having a plane orientation of <110> is used. In this embodiment, when the ink supply ports 2 and 2a are formed by etching, the etching progresses perpendicularly to the substrate. Therefore, as shown in FIG. The ink supply port with less number can be easily obtained. Accordingly, the substrate size in this embodiment is determined by the pattern on the substrate surface, and the size of the recording head can be further reduced. In addition, when the ink supply port having the shape shown in FIG. 3C is formed, the ink supply port can be easily formed by performing etching with the above-described configuration, but may be formed by another method such as sandblasting or laser processing. . When the ink supply port having the shape shown in FIG. 3C is formed by another method, it is not necessary to use a silicon substrate having a plane orientation of <110> as a material of the substrate.
[0020]
In the present embodiment, in addition to the recording head 300 capable of discharging the above-described Y, M, and C inks, the ink flow path forming member 12 has a discharge port for discharging black ink (Bk). A recording head 400 having rows 40 and 41 is fixed, and these are combined to form a recording head cartridge capable of ejecting four colors of ink. Since black is not generally used for forming secondary colors, it is not necessary to arrange it symmetrically. Further, in order to improve the printing speed in monochrome printing, a larger number of nozzles are provided than heads of other colors. In this embodiment, the ejection port arrays 40 and 41 for Bk are arranged such that the ejection ports complement each other in the scanning direction, similarly to the ejection port arrays 21 and 31. The recording can be performed in the sub-scanning direction at twice the density of the nozzle arrangement density. In this embodiment, printing can be performed in the recording mode as described in the first embodiment.
[0021]
(Third embodiment)
FIG. 5 is a view showing a recording head according to the third embodiment of the present invention. In the present embodiment, portions having the same functions as those in the above-described first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted. FIGS. 5A and 5B are explanatory diagrams schematically showing main parts of the recording head, wherein FIG. 5A is a schematic diagram viewed from above, and FIG. 5B is a cross-sectional view. In the present embodiment, the ejection port arrays 24 and 34 for ejecting Bk are provided in the first and second ejection port array groups, respectively. In each of the above-described embodiments, as the type of liquid to be superimposed, cyan, magenta, and yellow inks, which are most frequently used in the inkjet recording field, have been described as examples. The types of liquids that can be superimposed, such as green, blue, and red, may be other color combinations.
[0022]
(Other)
Finally, the liquid ejection recording apparatus in which the recording head or the recording head cartridge described in each of the above embodiments can be mounted will be described with reference to FIG. FIG. 6 is an explanatory diagram showing an example of a recording apparatus on which the liquid discharge recording head of the present invention can be mounted.
[0023]
In FIG. 6, a head cartridge 100 is exchangeably mounted on a carriage 102. The head cartridge 100 has a recording head unit 50 and an ink tank 200, and is provided with a connector (not shown) for transmitting and receiving signals for driving the head unit.
[0024]
The head cartridge 100 is mounted on the carriage 102 so as to be exchangeable while being positioned. The carriage 102 is provided with an electrical connection portion for transmitting a drive signal and the like to each head cartridge 100 via the connector. .
[0025]
The carriage 102 is guided and supported so as to be able to reciprocate along a guide shaft 103 installed in the apparatus main body and extending in the main scanning direction. The carriage 102 is driven by a main scanning motor 104 via driving mechanisms such as a motor pulley 105, a driven pulley 106, and a timing belt 107, and its position and movement are controlled. Further, a home position sensor 130 is provided on the carriage. Accordingly, when the home position sensor 130 on the carriage 102 passes through the position of the shielding plate 136, the position can be known.
[0026]
The recording medium 108 such as a printing paper or a plastic thin plate is separated and fed one by one from an auto sheet feeder (hereinafter ASF) 132 by rotating a pickup roller 131 from a feed motor 135 via a gear. Further, by the rotation of the conveying roller 109, the sheet is conveyed (sub-scanning) through a position (printing section) facing the ejection port surface of the head cartridge 100. The conveyance roller 109 is driven by a rotation of an LF motor 134 via a gear. At this time, the determination as to whether or not the paper has been fed and the determination of the cueing position at the time of paper feeding are performed when the recording medium 108 has passed the paper end sensor 133. Further, the paper end sensor 133 is used to actually determine where the rear end of the recording medium 108 actually exists and finally determine the current recording position from the actual rear end.
[0027]
The recording medium 8 has its back surface supported by a platen (not shown) so as to form a flat print surface in the print section. In this case, the head cartridge 100 mounted on the carriage 102 is held so that their ejection port surfaces protrude downward from the carriage 102 and become parallel to the recording medium 108 between the two pairs of transport rollers. I have.
[0028]
The head cartridge 100 is mounted on the carriage such that the direction of the ejection port array is different from the above-described scanning direction of the carriage, and performs recording by ejecting liquid from these ejection port arrays. In each of the embodiments described above, in order to eject ink using thermal energy, the electrothermal converter that generates thermal energy is provided. Of course, other methods such as ejecting ink by a piezoelectric element are used. There may be.
[0029]
【The invention's effect】
As described above, according to the present invention, the first ejection port array group and the second ejection port array group each include a dye ink in which the colorant is composed of only a dye and a dye ink in which the colorant is composed of only a pigment. An image can be formed only by the dye ink or an image can be formed only by the pigment ink by discriminating the scanning directions by ejecting the pigment ink. Further, by using both the dye ink and the pigment ink in bidirectional printing, an image having both advantages of a dye and a pigment can be printed at a high speed.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a main part of a recording head according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating an example of a print head cartridge on which the print head according to the first embodiment of the present invention is mounted.
FIG. 3 is an explanatory diagram illustrating a main part of a recording head according to a second embodiment of the present invention.
FIG. 4 is an explanatory diagram illustrating an example of a printhead cartridge on which a printhead according to a second embodiment of the present invention is mounted.
FIG. 5 is an explanatory diagram illustrating a main part of a recording head according to a third embodiment of the present invention.
FIG. 6 is an explanatory diagram showing an example of a recording apparatus on which the liquid discharge recording head of the present invention can be mounted.
[Explanation of symbols]
Reference Signs List 1 discharge port 2 ink supply port 3 drive circuit 4 contact pad 5 energy conversion element (heating resistance element)
6 Orifice plate 7 Substrate 8 Wiring 9 Contact pad 10 Liquid flow path 11 Electrical connection portion 12 Ink flow path forming member 13 Wiring board 20 First discharge port row group 21, 22, 23, 24 Discharge port row 30 Second Ejection port array group 31, 32, 33, 34 ejection port array 40, 41 ejection port array 50 print head unit 100 print head cartridge 150 tank holder 200 ink tank 230 pixels (pixels)
231,232 dot positions

Claims (7)

A first ejection port array group that ejects liquids containing yellow, magenta, and cyan colorants from three ejection port arrays arranged in a direction different from the scanning direction while scanning the recording medium bidirectionally. The first discharge port row group is formed by a head composed of a second discharge port row group in which discharge port rows of respective colors are arranged on the same substrate in line symmetry with respect to the discharge port row group and the discharge port row row. Liquid ejection recording wherein the ejection ports to be formed and the ejection ports forming the second ejection port array group are arranged to be offset from each other in the arrangement direction of the ejection ports so as to complement each other in the scanning direction. A liquid discharge recording head, wherein the colorant of the ink in one of the ejection port arrays is made of a dye, and the colorant of the ink in the other ejection port row is made of a pigment. A discharge for discharging a liquid different from the liquid discharged from the first and second discharge port row groups and the liquid corresponding to the liquids separately from the two discharge port row groups according to claim 1. 2. The liquid discharge recording head according to claim 1, further comprising an outlet row or a discharge port row group. 3. The liquid recording / ejection head according to claim 2, wherein the liquid ejected from the new ejection port array or the ejection port array group according to claim 2 is black ink containing a dye, a pigment, or both. . A recording method for forming an image using only the dye ink by scanning in only one direction using the recording head according to claim 1. A recording method for forming an image using only the pigment ink by scanning only in the direction opposite to that of the recording head using the recording head according to claim 1. A recording method for forming an image by simultaneously using a dye ink and a pigment ink by bidirectional scanning using the recording head according to claim 1. An ink jet recording apparatus comprising means for selecting any one of the means according to claims 4 to 6.

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