JPH04118250A - Printing process in multicolor ink- jet printing and ink jet pen used therein - Google Patents

Abstract

PURPOSE: To minimize color stripes, a color mixture and color bleeding by horizontally, continuously and selectively ejecting ink dot arrays to a predetermined printing part from separate vertically shifted nozzle arrays. CONSTITUTION: A large number of color exclusive nozzle arrays are vertically arranged along one dimension of a nozzle plate 12 so as to become vertical to the horizontal operation direction of the nozzle plate. Each of the nozzle arrays is exclusive only to one color of cyan, yellow, magenta or black being a principal ink color and the nozzle of each array vertically shifted by the distance of one dot array in relation to the nozzle of each adjacent array 1 but the nozzles of the respective arrays are arranged in a mutually staggered state. Therefore, in the selective ejection of these nozzles at a time when a printing medium is horizontally allowed to traverse or pass, three or more vertically arranged dot arrays are always never bonded simultaneously or respectively and continuously. At first, the nozzle plate 12 is moved from a right- hand first position, that is, a start position to a second position 42 in the direction shown by the arrow in a drawing to form a dot pattern 44. The nozzles 46, 48, 50, 52, 54 of the nozzle plate 12 are simultaneously subjected to ejection in order to form two upper cyan dot arrays 56, 58 and three lower magenta dot arrays 60, 62, 64.

Description

[Detailed description of the invention]

[0001]

[Industrial application field]

FIELD OF THE INVENTION The present invention relates generally to ink jet printing;
Improved multicolor dot-next-dot (DND) to reduce color fringing and bleeding on print media.
) Concerning the inkjet printing process. This process helps improve the overall ink jet print quality on the print media. [0002]

[Background Art and Problems to be Solved by the Invention] In recent years, there has been significant progress in the field of color inkjet printing, and much of that progress has been achieved by printing on plain paper, special paper, and various types of second base paper. It is concerned with improving the print quality of media. Representative advances in the art and technology include the various improvements and developments embodied in the Hewlett-Paracard printjet printer, which first hit the market in August 1987. Regarding this, please refer to the Heuret Paracard Journal (1988
August issue, Vol. 39. Details are described in No. 4). [0003] In the field of multicolor ink sheet printing, ink jet pens have primary color nozzles or orifice groups arranged adjacent to each other along the longitudinal dimension of the printhead, often perpendicular to the movement of the printhead. (also called printheads). As the printhead is moved from side to side with respect to adjacent print media, nozzle groups dedicated to each color are fired simultaneously to create a combined swath width ( combined swath width). For example, the three-color thermal ink jet pen disclosed in U.S. Pat. There are 16 nozzles in each group. Therefore, when the pen is moved relative to the print medium and scans from side to side of the print medium, a total of 48
Three separate adjacent color stripes can be created that result in a vertical row of dots. [0004] The thermal ink jet color pen disclosed in U.S. Pat. No. 4,812,859 functions quite satisfactorily in most respects; causes color streaks or undesirable color bleeding or color mixing. All of these undesirable characteristics in print quality can result from insufficient drying of the printed ink on a given surface of the print medium. Therefore, this insufficient drying of the ink results in successive fill colors (s
(solid color fill) may result in color streaks. The ink beads up at small angles and clean round curvatures across the width of the print swath, and as a result of that phenomenon, the ink in the swath edge dries more quickly than the ink inside the swath. This causes the swath edges to become brightly colored and can be seen as thin light-colored stripes running horizontally across the swath. Color fringing is therefore used in ink jet printing technology to describe this undesirable characteristic of print quality. [0005] In other printing techniques, this excessive amount of ink per unit time and unit printing area can cause undesirable color ink when printing different colors in direct side-by-side contact to provide a two-color interface. May cause smearing or color mixing. If these two colors are printed at the same time or in quick enough succession, the wet ink at the boundary between the two colors will bleed to the sides of this boundary and the ink of the other different colors will not dry completely. Mixes with ink. This interaction results in undesirable visible smearing at the interface of the two colors. [0006] The problem of color streaking and color bleeding results in more ink being deposited over adjacent printed portions of the print media per unit time and unit area than allows for sufficient and uniform drying of the ink. Caused by adjacent swath prints. Print media, such as untreated plain paper, may contain many dot rows per swath arranged in the nozzle configuration of adjacent color printheads in the previously mentioned U.S. Pat. No. 4,812,859. A swath portion having a width determined by adjacent rows of dots that are printed at the same time cannot sufficiently absorb printed ink when the printing speed is higher than a predetermined printing speed. [0007]

[Means for explaining the issue]

It is a general object of the present invention to provide a novel and alternative approach to multicolor ink jet printing that is operable symmetrically with the simultaneous printing of adjacent swaths of different colors as previously described. This new approach helps minimize or eliminate the undesirable printing characteristics of color fringing, color mixing, and color bleeding. This is ink ejected from separate vertically offset rows of nozzles in an ink jet pen or printhead that prints a series of selected ink dots horizontally and sequentially over a predetermined print area. This is achieved according to the present invention. These selected dot rows fill a continuous fill area (Solid area fi) of the desired image or predetermined portion.
ll) can be printed simultaneously or in rapid succession or both until all the required nozzles are fired. The nozzle firing sequence never prints more than two adjacent rows of dots in the time required for the nozzle plate to traverse or pass a certain dimension of the predetermined print portion of the print media. . [0008] In a preferred embodiment of the invention, the process uses a novel nozzle plate geometry in which multiple color-specific nozzle rows are arranged vertically along one dimension of the nozzle plate, and as previously described. The nozzle plate extends vertically to the horizontal direction of motion. Each nozzle row is dedicated to only one primary ink color, such as cyan, yellow, magenta, or black, and the nozzles in each row are perpendicular to each adjacent row 1 nozzle by a distance of one dot row. be staggered or staggered. Therefore, the selective firing of these nozzles as they horizontally traverse or pass the print media is such that at any given time, more than two vertically oriented dot rows are never deposited simultaneously or in rapid succession. This operation covers one printing portion required to print the desired image or continuous fill area on the previously mentioned predetermined portion, and also as the nozzle plate completes all of its multiple passes. Continued. The vertical dimension of this predetermined portion occupies substantially the same space as the vertical dimension of the nozzle plate. [0009] Another object of the present invention is to provide a method for printing without sacrificing printing speed.
The object of the present invention is to provide a new and improved color printing process of the kind already mentioned for minimizing color fringes and bleeding. [0010] Another object of the present invention is to improve ink-jet color printing, which improves the ink drying uniformity over a given print area, thereby improving the overall print quality of the color image printed within that area. The objective is to introduce a new and improved process for 1S Kaihei 4-118250(7) [0011] Another object is to improve color print quality on low absorbency print media with low drying coefficients, such as certain grades of office paper and second base paper. It is particularly useful to bring about the new potash-improved process mentioned above. [0012] A feature of the present invention is the provision of a multicolor ink jet printing process of the type already described, which increases the average drying time between the various color dots printed adjacent to each other on the print medium. [0013] Another feature of the present invention is to utilize full-speed, multi-pass printing to achieve the The purpose of the present invention is to provide a new nozzle plate shape. The nozzles in each row are vertically offset with respect to the nozzles in an adjacent row by a predetermined distance equal to one dot row, and each nozzle row has a means for fluidly combining separate ink colors. It is provided. [0014] Another feature of the invention is to ensure that the total dry area never exceeds the maximum allowable area of a full width two-dot row.
It is the provision of a new and improved process of the kind already described, which provides a horizontal ink drying boundary between only two solid filled print rows. [0015] Another feature of the invention is the provision of a color ink jet pen for creating graphic color pixels interspersed at the dot column level. This minimizes the visible effects of scan line errors on the print media. [0016] Another feature of the present invention is the provision of an improved nozzle plate geometry that can be operated in conjunction with currently available printing algorithms to reduce color fringing. The above objects, features and various related advantages of the present invention will be better understood with reference to the following description of the accompanying drawings. [0017]

【Example】

In FIG.
A jet pen 10 is shown. The barrier layer 14 is -
A thin film resistor (TFR) support 16 formed of a polymeric material such as a commonly known insulator (VACREL) and having a general structure and architecture well known in the art.
Fixed. In the field of thermal ink jet printing, these thin film resistor supports 16 are typically used to have photolithographically defined heater resistors (not shown) aligned with the ink ejection openings of the orifice plate 12. The structure can be described in the previously mentioned Hewlett-Paracard Journal (198
August 198 issue (vo 136. No. 4) Heuret Paracard Journal (May 198 issue, v
o136. No. 5), and U.S. Patent No. 4.812
．． No. 859 (Shi Nis Chan: C, S, Cha
n) is described in detail. These ink ejection openings are also called "orifices" or "nozzle holes" in the field of ink jet printing. [0018] The thin film resistor support 16 is on one surface of the pen body housing 18 which has separate ink storage compartments 20.22.24.26 containing the primary ink colors cyan, magenta, yellow, and black. It is attached. This ink storage consists of an ink storage compartment 20.2
2.24, and 26, and the process used for foam storage in pen body housing structures of this type is described in U.S. Pat.・Baker: Jeffrey P. Baker). [0019] The orifice plate 12 of FIG. 1 is also shown in an enlarged top view in FIG. 2, and is fluidly separated from each other and has four primary ink colors, cyan, cyan, and the like, as shown.
Nozzle 30.32 supplied with magenta, yellow, and black
．． 34, and 36. Each of these nozzle rows is separated from the adjacent column by a width dimension W and is vertically offset from the adjacent nozzle position by a length dimension, as shown in FIG. JP-A-4-118:250 (9), the center-to-center spacing between adjacent nozzles of similar color in any of nozzle rows 30, 32, 34, and 36 is as shown in FIG. The size is four times the number of nozzle rows, that is, 4D. Using a print density of 300 dots per inch (DPI), the dimensions are approximately 0.0033 inches (1/300") and W is generally in the range of 25D to 32D. [0020] Now FIG. 3A ~ Referring to Figure 3D, the orifice
The plate or nozzle plate 12 is first moved from a first or starting position 40 to a second position 42 on the right side of the figure in the direction of the arrow shown to form a dot pattern 44, as shown in FIG. 3A. Form. Nozzles 46, 48, 50, 52, and 54 of nozzle plate 12 have two upper cyan dot rows 56 and 5 as shown.
8 and three lower magenta dot rows 60, 62, and 64 simultaneously. [0021] To perform another left-to-right pass as shown in FIG. 3B, the nozzle plate 12 is first moved vertically down a distance of one dot column with respect to the print medium, and then the nozzle 46, 50, 52, and 54 are simultaneously injected to form dot rows 66, 68, respectively, of the generated dot pattern 74.
．． 70 and 72 are added. [0022] Now referring to FIG. 3C, the force plate cyan nozzle 46 is moved down one dot column in this next scan to form an additional column of cyan dots 76, and the magenta nozzle 50 is moved down to the lower magenta nozzle.・Joining dot row 78, magenta nozzle 5
2 also joins magenta dot row 80, and magenta nozzle 54 joins the lowest magenta dot row 82 to form dot pattern 84. [0023] Finally, in the fourth and final left-to-right pass shown in FIG. 3D, these same cyan and magenta nozzles 46, 50, 52, and 54 nozzle A left-to-right motion of plate 12 is fired simultaneously to add a cyan dot row 86 and three magenta dot rows 88.9o and 92. This pass, shown generally at 94 in FIG. 3D, completes a continuous color gamut filling pattern that defines one cyan/magenta interface boundary 96. Therefore, the full continuous color area filling pattern 94 of FIG. 3D can be printed simultaneously or in rapid succession by the ink jet pens of FIGS. 1 and 2 without printing more than two adjacent and touching rows of dots. You can see that it is printed. [0024] Referring now to FIGS. 4A-4D, an ink jet printing process operated in accordance with the present invention is illustrated in which four sequential fills of cyan, magenta, yellow, and black are printed. Regions are formed adjacent to each other and define vertical and horizontal interface boundaries of separation therebetween. In FIG. 4A, orifice plate 12' is moved from right-hand position 98 to left-hand position 100 in the direction of the arrow. During this pass, nozzle 1 on nozzle plate 12'
02104.106.108.110.112.114
．． 116 and 118 are respectively a cyan column 120, a yellow column 122, a cyan column 124, a yellow column 126, a black column 128,
It is injected to form a magenta column 130, a black column 132, a magenta column 134, and a black column 136. [0025] The orifice from the left side position to the right side position shown in FIG. 4B.
In the next pass of plate 12', black column 140, cyan column 142, yellow column 144, magenta column 146, black column 148,
Simultaneously with the formation of magenta rows 150 and black rows 152,
A cyan column 138 is formed using cyan nozzle 102. The latter seven rows each include nozzles 104106.110.112.114.116 of nozzle plate 12'.
, and 118. [0026] In the next right-to-left pass shown in FIG. 4C, the nozzle plate 12' is first moved one dot column below the position shown in FIG. 4B and then moves to nozzle positions 98 and 100. Across the scanned portion between the cyan, yellow, magenta, and black columns 154▽. 156▽. 158.160.162.
164, 166, and 168 are added. [0027] In the final horizontal pass of this example, the continuous area color fill pattern 170 shown in FIG.
72.174.176.178.180, and 182
is added. In this fourth right-to-left pass shown in Figure 4D, nozzles 102.104.107.11o,
112, 114, 116, and 118 are injected,
Two top continuous fill regions of cyan and yellow and two bottom continuous fill regions of magenta and black are formed. As can be seen from this pattern 170, the upper blocks of cyan and yellow are separated from the lower blocks of magenta and black by continuous horizontal C/M and Y/ color boundaries and continuous vertical C/Y and M/ color boundaries. Separated. Formation of these continuous area color filling patterns and associated C/
M and Y/horizontal color boundaries never require the deposition of more than two adjacent dot rows simultaneously or in rapid succession in a single pass of the ink jet pen. Also,
It is important to note that when forming vertical color boundaries on consecutive C/Y and M/, two horizontally adjacent dots of different colors are never deposited (printed) simultaneously or in rapid succession during one printing pass. It will be understood from the previous description of FIGS. 4A to 4D. [0028] Using this process for forming continuous primary color filled areas, the amount of ink deposited per unit time and unit area is less than that deposited per unit time and unit area of known prior art processes. The amount is about 174. Generally, in accordance with the present invention, it is found that the ink density deposited is inversely proportional to the specific number of color nozzle columns used. [0029] Various changes may be made in the embodiments described above without departing from the scope of the invention. for example,
The number of nozzles in each nozzle column can essentially be increased, and the size, shape, dimensions and spacing of these nozzles can vary depending on the particular ink jet pen being used.
It depends on the jet printing application, but can be varied over a wide range. Additionally, this pen may be used with ink jet transducers other than thermal ink jet heater resistors (e.g. piezoelectric types),
It can be modified for use with ink storage methods other than foam storage. Examples of other suitable ink storage methods and pen body constructions include U.S. Pat. No. 4,791.
No. 438 (Gary E. Hanson)
There is a capillary ink supply system disclosed in Hanson et al. [0030] The present invention is not limited to the use of one nozzle plate and corresponding one ink jet pen, but instead, for example, two or more having the same adjacent nozzle row relationship as already mentioned. It must also be understood that it is possible to use pens in close proximity to each other. In such an alternative construction, it may be desirable to use three colored pens with another black pen in a close arrangement on a common pen carrying nozzle member. This alternative application allows two or more separate pens to be interchanged independently of each other, especially when using disposable ink jet pens in printing applications with large discrepancies in ink color demand. desirable. [0031] The present invention is further compatible with and effective with super pixeling printing processes, where dot-next-to-dot (DND) printing is used for color mixing of the pixel matrices that make up the super pixels. You also have to understand that. For example, this matrix is 2
It can be divided into X2 or 3X3 superpixels, and segmented sections of the superpixel are selectively printed with different ink colors to form a secondary color fill. For example, 2X2 superpixel quadrants are printed with the primary ink colors magenta/yellow, cyan/yellow, and cyan/magenta to create the secondary colors red, green, and blue, respectively. Can be printed selectively. [0032] Accordingly, the present invention proposes a novel approach to the temporal and spatial separation of ink droplets (dots) printing on print media. can be further combined with super-pixeling techniques to add further dimensions of . This combination also serves to further enhance drying uniformity and print quality of the print media. [0033] Finally, many types include dot-on-dot (DOD)
In a flossing process, the first deposited droplet of a given print area is exposed to a drying film before another droplet is deposited directly on top of it.
Opening 4-118. It is also understood that the present invention is also compatible and effective with dot-on-dot (DOD) printing processes, as '250 (13) or substantially dry printing is required. The large spatial distribution of single pass droplets deposited according to the present invention maximizes overall drying time and minimizes color bleeding. This feature allows faster DOD printing speeds by reducing the time from the first pass drop to the second pass of overlapping drops. [0034]

【Effect of the invention】

As explained above, according to the present invention, color fringes and color bleeding on a print medium in inkjet printing can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a multicolor ink jet pen according to the present invention.

2 is a plan view of the orifice plate of the multicolor ink jet pen of FIG. 1; FIG.

[Figure 3] FIG. 3 is a schematic explanatory diagram showing a printing process according to the present invention.

[Figure 4] FIG. 7 is a schematic explanatory diagram showing another printing process according to the present invention.

[Explanation of symbols]

10: Ink jet pen 12: Nozzle plate 20.22.24.26: Ink storage compartment 30.32.34.36: Nozzle row

【Document name】

[Figure 1] drawing

[Figure 2] 1N Kaihei 4-118'250 (15) [Figure 3A] [Figure 3B] [Figure 3C] [Figure 3D] [Figure 4A] [Figure 4B] 71 Kaihei 4-118"50 (21") [Figure 4C] [Figure 4D]

Claims (6)

[Claims] Claim 1: Printing a row of ink dots across a predetermined print portion of a printing medium, and printing two or more dot rows simultaneously or successively across the predetermined print portion. A printing process in multicolor inkjet printing, characterized in that the predetermined printing portion is scanned to complete the dot row. [Claim 2] Ink is ejected to print a plurality of dot rows from a plurality of vertically shifted color-dedicated nozzle rows provided on a nozzle plate, so that the first color print portion is linear. , thereafter, the nozzle plate is operated on the printing medium at predetermined intervals, and printing is performed on a second printing area adjacent to the first printing area on the printing medium.・Printing process in jet printing. 3. A plurality of adjacent nozzle rows are offset along the length of the nozzle plate by the width of one row of dots printed horizontally across a predetermined printed portion of the print medium. aligning the color-specific nozzles of the nozzle plate by the method and selectively ejecting said nozzles to print multiple dot rows without simultaneously or consecutively depositing two or more adjacent dot rows; Characteristics of the printing process in multicolor inkjet printing. 4. Ink ejecting nozzles containing ink of different colors are prepared for each adjacent row, and the ink ejecting nozzles are vertically shifted from one row to another at predetermined intervals, so that the nozzle rows are moved close to each other. The ink is passed through the print medium a predetermined number of times, and each row of nozzles is ejected continuously at a rate that deposits up to two adjacent dot rows simultaneously or continuously, and the ink is deposited on the print medium. The number of dot rows in the printed part that dries to reveal the boundaries between adjacent dot rows is limited to two rows.
The printing process in multicolor inkjet printing is characterized by: 5. Different colors of a plurality of color inks are prepared for each adjacent row of a plurality of ink ejection nozzles, and the ink ejection nozzles are operated on adjacent print media to perform print scanning. The continuous passage of the ink ejection nozzles horizontally across the area ejects only predetermined ink ejection nozzles in each nozzle row, ejecting ink necessary to print a desired color image on the print scanning area. A printing process in multicolor ink jet printing characterized in that all ink ejection nozzles that require ejection eject through completion of all passages of the nozzles until all ink ejection nozzles that require ejection have finished ejecting. 6. A nozzle plate having spaced apart rows of nozzles vertically offset with respect to nozzles in adjacent rows at predetermined intervals; An inkjet pen used for multicolor inkjet printing, comprising: an element for supplying color ink of a different color for each column;