JP2001138552A - Ink color arrangement of ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate granular feeling of a pattern printed on a recording sheet and to obtain a print where both high color reproducibility and high density representation are realized. SOLUTION: In a color ink jet recorder where dot groups are formed in parallel while arranging a plurality of dots in the longitudinal direction when a print head having dot forming parts for forming a plurality of colors on a recording sheet is moved above a recording sheet in the direction orthogonal to the carrying direction thereof, a print head mounting cyan, magenta, yellow, light magenta, orange, green, and black is employed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color ink jet recording apparatus which expresses multiple colors by superimposing a plurality of colors.

[0002]

2. Description of the Related Art Conventionally, the operation of a print head is controlled by a microcomputer, and a direction perpendicular to a conveying direction of the recording paper (hereinafter referred to as a sub-scanning direction) is formed on the recording paper supplied by a paper feeding device. 2. Description of the Related Art There is known an ink jet printer that performs predetermined printing by an ink jet method using an ink head that moves in a main scanning direction.

FIGS. 4, 8 and 9 are explanatory views of a conventional print head. As shown in FIG. 4, the print head 100 has a black (K) inkjet element group 1.
And a cyan (C) inkjet element group 2, a magenta (M) inkjet element group 3, and a yellow (Y) inkjet element group 4. Each of the inkjet dot element groups 1 to 4 ejects ink of each color to form dots of that color on recording paper. Then, the print head moves in the main scanning direction orthogonal to the sub-scanning direction of the recording paper (in the direction of the arrow), and one line of printing is performed on the recording paper.

The print head 101 shown in FIG. 8 is black (K).
Inkjet element group 5, a cyan (C) inkjet element group 6, a magenta (M) inkjet element group 7, a yellow (Y) inkjet element group 8, and a light cyan (LC) color inkjet element group. It has an inkjet element group 9 and an inkjet element group 10 of light magenta (LM) color.

Each of the ink jet dot element groups 5 to 10
Ejects ink of each color to form dots of that color on recording paper. Then, the print head moves in the main scanning direction (the direction of the arrow), and one line of printing is performed on the recording paper.
The print head 102 in FIG. 9 includes a black (K) inkjet element group 13, a cyan (C) inkjet element group 14, and a magenta (M) inkjet element group 1.
5, a yellow (Y) inkjet element group 16, an orange (OR) inkjet element group 17, and a green (GR) inkjet element group 18.

Each of the ink jet dot element groups 13 to 1
Numeral 8 ejects ink of each color to form dots of that color on recording paper. Then, the print head moves in the main scanning direction (in the direction of the arrow), and one line of printing is performed on the recording paper. That is, the conventional ink configuration shown in FIG. 4 or FIG. 9 has a problem that it is difficult to output an intermediate color because of the configuration of the primary color and the dark color. In addition, the color configuration shown in FIG. 8 has a problem that a wide range of orange and green color reproducibility and density cannot be obtained due to a relatively light color configuration such as light magenta and light cyan.

FIG. 2 shows an example of gradation expression in which a conventional print head having black, cyan, magenta, and yellow colors uses one of the colors to show a single-color gradation.

Regarding the arrangement of dots for 25% printing, one dot is arranged in four squares in two columns and two columns. 5
With respect to the arrangement of dots for 0% printing, two dots are arranged, and for the arrangement of 75% printing, three dots are arranged.
Therefore, when printing is performed based on the color of the recording paper, a granular feeling appears.

FIG. 3 is a graph showing color reproduction by a print head using black, cyan, magenta, and yellow. The part 19a that transitions from yellow to red
Results in poor reproduction of orange shades. And the part 1 that shifts from cyan to green
9b, the reproduction of the green tint is poor. Further, in the conventional multi-color ink jet printer, an ink jet printer equipped with six color inks is mainly used, and depending on the color required by the user, an orange (O) ink is required.
It was necessary to replace R) and green (GR) inks with light cyan (LC) and light magenta (LM) for printing.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned various problems of the prior art, and an object of the present invention is to make a pattern printed on a recording paper by a print head without graininess. Another object of the present invention is to provide a print head configuration that achieves both printing with high color reproducibility and high expression of density.

[0011]

A print head provided with a dot forming section for forming a plurality of colors on a recording paper is provided.
In a color ink jet recording apparatus that forms a dot group by arranging a plurality of columns in a row and moving in parallel in a direction perpendicular to a conveyance direction of the recording paper on the recording paper.
Cyan, magenta, yellow, light cyan,
It is characterized by having a print head equipped with light magenta, orange, green, and black.

Therefore, according to the present invention, light cyan and
By providing light magenta, rich gradation expression is possible, and color expression power with excellent image quality without graininess is possible.Furthermore, the color reproduction area is expanded by installing it on the same print head as orange and green The bright red of apples and the fresh green of vegetables can be output as intended.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of an embodiment according to the present invention will be described in detail with reference to the accompanying drawings. The recording head 29 shown in FIG. 1 is the print head shown in FIG. The head drive circuit 28 is for driving the recording head 29.

The control unit controls the head drive circuit 28 in accordance with an instruction from the CPU 30. The CPU 30 sends to the control unit 31 a signal for selecting a dot element group of a color to be driven according to a gradation signal received from an external computer or the like. The ROM 32 is connected to the CPU 30, and a RAM 34 including a control program for the CPU 30 and a target table of driving colors for gradation signals is connected to the CPU 30.
Record the data for 30.

The recording paper feeder 33 feeds the paper one line at a time by one motor, or prints one line at a time, or prints one-half line, one-quarter line, one-eighth line, and one-sixteenth line. /
Send in the direction of 2 line feed, 1/4 line feed, 1/8 line feed, 1/16 line feed. The carriage mechanism 35 feeds the recording head 29 in the main scanning direction by a motor. The motor driver 37 drives a motor of the recording paper feeder and a motor of the carriage mechanism under the control of the CPU 30.

Further, an example of an embodiment of the configuration of the print head according to the present invention will be described in detail. As shown in FIG. 7, the print head unit 105 includes an orange (OR) inkjet element group 20 and a green (GR) inkjet element group 21 in a print head 103 that is displaced in the sub-scanning direction. , Light cyan (LC) inkjet element group 22 and light magenta (LM)
And a group of color inkjet elements 23.

In the print head 104, a black (K) ink jet element group 24 and a cyan (C)
A color inkjet element group 25, a magenta (M) inkjet element group 26, and a yellow (Y) inkjet element group 27 are sequentially arranged in the main scanning direction.

In this embodiment, each ink jet element group is composed of 9 rows and 2 columns of ink jet elements in the sub-scanning direction, and each head element ejects ink by piezoelectric driving. The print head unit 105 is main-scanned in the direction of the arrow in FIG. The recording paper is sub-scanned in a direction perpendicular to the main scanning direction. Next, this operation will be described.

The main scanning of the print head is performed in the direction of the arrow in FIG. First, black (K) dots are formed, and then cyan (C), magenta (M), and yellow (Y) are formed.
In this embodiment, the ink is ejected in the order of the colors, and in this embodiment, the ink is projected in the sub-scanning direction as shown in FIG. Is done. Therefore, the recording paper is then line-feeded in the sub-scanning direction and printed on the recording paper while overlapping the dots in the order of orange (OR), green (GR), light cyan (LC), and light magenta (LM). You.

FIG. 5 shows a print head having black, cyan, magenta, yellow, light cyan, light magenta, orange, and green according to the present embodiment.
5 is a gradation expression example showing gradation using a half density cyan ink or a magenta ink with a half density. Regarding the arrangement of the dots of 25%, two dots of the 系 density ink of the light system are arranged in four squares of two columns and two columns. Regarding the arrangement of 50% dots, four dots of 1/2 density ink of the light system are arranged. In the arrangement of 75%, two primary color dots and two dots of the 系 density ink of the light system are arranged.

Also, by using 1/2 density ink, 12.5% arrangement, 37.5% arrangement, 62.5%
The combination of% arrangement and 87.5% becomes possible. Therefore, the gradation expression is enlarged, resulting in a smooth gradation and no graininess. FIG. 6 is a graph showing color reproduction by a print head using black, cyan, magenta, yellow, light cyan, light magenta, orange, and green. At the transition from yellow to red, the range of reproduction of the orange and green shades is widened as indicated by the diagonal lines.

The print head unit 105 of the embodiment of the present invention shown in FIG.
The print heads are divided into two groups, each of which has an element group of four colors. However, an inkjet element group of eight colors may be provided in one print head. In this case, the relative position adjustment between the two print heads becomes unnecessary, and the head position adjustment step can be omitted.

In addition, eight single color print heads may be used. In this case, even if one ink jet element group is destroyed for some reason, it is advantageous to replace one head and to obtain a good yield. .

[0024]

As described above, according to the present invention,
The following effects are obtained. By using light cyan and light magenta, when printing highlights and gradations, rich gradation expression is possible and smooth printing without graininess is achieved. In addition, the use of orange and green enlarges the color reproduction area, and makes it possible to express vivid colors. It is possible to perform excellent printing simultaneously having two different expressions, that is, a rich gradation expression and a wide color reproduction area. In addition, it is possible to eliminate the trouble and the waste of replacing the ink color depending on the needs.

[0025]

[Brief description of the drawings]

FIG. 1 is a block diagram according to the present invention.

FIG. 2 is a diagram showing printing by a conventional color print head.

FIG. 3 is a graph showing color reproduction by a conventional color print head.

FIG. 4 is an explanatory view of a conventional color print head.

FIG. 5 shows a print according to the invention.

FIG. 6 is a graph showing color reproduction according to the present invention.

FIG. 7 is an explanatory view of an embodiment of the present invention.

FIG. 8 is an explanatory view of a conventional color print head.

FIG. 9 is an explanatory view of a conventional color print head.

[Explanation of symbols]

 1-18 Inkjet element group 20-27 Inkjet element group 28 Head drive circuit 29 Recording head

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA04 EA06 EA11 ED05 ED07 EE08 EE18 FA02 FA10 5C051 AA02 CA04 DA06 DA09 DC02 DE05 EA01 EA02 EA03 FA01 5C074 AA05 BB16 CC26 DD23 GG08 GG09 HH02

Claims (1)

[Claims] A print head provided with a dot forming section for forming a plurality of colors on a recording sheet moves in a direction perpendicular to a direction in which the recording sheet is conveyed on the recording sheet. And a color inkjet recording apparatus that forms one dot group in parallel with a color inkjet having a print head equipped with black, cyan, magenta, yellow, light cyan, light magenta, orange, and green. Recording device.