JPH0241421B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording method, and more particularly to an inkjet recording method in which a color image is recorded by reciprocating a plurality of recording heads for inks of different colors at right angles to the paper conveyance direction. .

An example of a color recording apparatus using a multi-head for inks of different colors as described above is an inkjet printer that performs color recording by subtractive color mixing by ejecting ink from an ink jet nozzle and depositing it on the same location on a recording sheet.

Color recording using conventional inkjet is the first
As shown in the figure, the three colors yellow, magenta, and cyan (hereinafter abbreviated as Y, M, and C, respectively), or the four colors in which black (hereinafter abbreviated as B) is added to the above three colors.
Images are recorded by subtractive color mixing, but since the same nozzle cannot be shared by multiple colors, four dedicated recording heads 1 for each color are arranged on a carriage 2, and this carriage 2 is connected to the platen of the recording paper 3. A so-called serial printing method is known in which an image is recorded while reciprocating in a direction perpendicular to the conveying direction (indicated by an arrow in the figure). Many of those that perform recording using this method perform recording on both the forward and backward passes in order to increase the recording speed.

This image recording apparatus that performs both forward and backward recording has the following drawbacks. That is,
In the above-mentioned apparatus, recording is performed by horizontally arranging the recording head 1 having a plurality of orifices (injecting holes) in one vertical row, so that the order of ejecting ink in the forward and backward passes during recording is different, as shown in Fig. 2. End (4 in the diagram)
An example of a recording head having three injection holes is shown, with the order of Y, M, C, B on the forward pass, and B, C, M, and B on the return pass.
Ink is ejected in the order of Y. ), the disadvantage was that the color development was different to varying degrees depending on the compatibility of the paper and ink, and the color of the finished product changed.

That is, when reciprocating recording is performed using a recording head 1 having a recording width l as shown in FIG.
As shown in the figure, the result is a color recording with different shades at every interval l.

This is because in a normal inkjet printer, subtractive color mixing of multiple inks is performed on the recording paper, and if the order in which the colors are mixed on the recording paper differs between the forward pass and the return pass, the colors produced by the subtractive color mixture will be different. However, if one attempts to perform dot recording in only one direction in order to solve this problem, the return movement of the head ends up being just movement, resulting in a decrease in the recording speed.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional apparatus, and aims to provide an inkjet recording method that has a simple structure, can obtain a uniform color image, and can operate at high speed. .

In order to achieve the above object, the present invention includes a carriage on which an inkjet recording means is mounted and moves, and a means for conveying a recording medium to be recorded every predetermined recording width. The inkjet recording method performs recording by both movement, and the recording means includes a plurality of jetting ports for jetting a first color ink, which are arranged at a predetermined pitch in a direction different from the recording direction. a group of jetting ports, and a jetting port for jetting the second color ink is connected to the first jetting port.
A second nozzle group is arranged such that the number of nozzles in the nozzle group is the same as the nozzles in the first nozzle group, and the nozzles for ejecting the second color ink are disposed at different pitches so as to complement each other. a third jetting port group arranged at the pitch so as to correspond to each jetting port and having the same number of jetting ports as the first jetting port group; a fourth nozzle group arranged at the pitch so as to correspond to each of the nozzles of the second nozzle group and having the same number of nozzles as the first nozzle group; the overlapping order of the first and second color inks by the group and the third jet port group;
Recording is performed such that the overlapping order of the second and first color inks by the second jetting port group and the fourth jetting port group is alternated within the predetermined recording width according to the pitch. This is an inkjet recording method.

With the above configuration, the present invention can achieve high-speed recording with substantially constant density unevenness in image quality simply by using a relatively small recording means.

The present invention also includes a recording means in which the number of injection ports is increased as in the configuration described later.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

FIG. 3 explains the partial concept of a recording head applied to the inkjet recording method of the present invention. Here, the recording head 10 is a head unit formed by a plurality of jetting orifice groups, each of which jets ink of different colors, and four orifices 10C for jetting ink are arranged at a predetermined pitch a apart on the surface facing the recording paper. 10A and 10B are arranged in parallel with each other by a/2. This pair of head units 10
A and 10B are independent from each other, and each has an ink supply tube at the rear opposite to the surface having the orifice 10C, and can receive recording ink of different colors.

In the image recording apparatus of the present invention, the above-mentioned recording head 1
0's for the required colors are lined up on a carriage to form a recording section. Figure 4 shows the above recording heads Y, M,
An example of arrangement as a color recording section for four colors, C and B, is shown. (In the figure, the recording heads 10, 10, 10, and 10 are shown as viewed from the recording paper side.) The color arrangement at this time is, for example, as shown above and below each recording head. The color arrangement of the head unit 10A shifted upward and that of the head unit shifted downward are reversed. By making such an arrangement, the pitch a between the orifices of each head unit 10A, 10B can be set to a desired image density P (dots/mm).
By setting a=2/P (that is, the deviation between each head unit is a/2=1/P), the desired image density can be obtained. Conversely, the orifice pitch of each head unit 10A, 10B can be constructed with double the pitch if the same image density as the conventional example is to be obtained, which makes manufacturing the head unit much easier. There are also advantages.

The recording section configured as described above can record eight dots at a time in one line, as shown in FIG. In other words, in the recording operation on the first line (illustrated with the arrow of the solid line in Fig. 4, Figure 5), the four hipsd units in the color of Y, M, C, and B, which are shifted to the upper side, are the four hipsd units 10a, 10a, 10
A, 10A is 4 in the same place in the order of Y, M, C, B
The lower four head units eject ink in the order of B, C, M, and Y. In other words, in the conventional example, a difference in color appears every four dots in the conveyance direction of the recording paper 3, whereas in the present invention, a difference in color appears only every four dots.

The human eye has a condition known as small-area tritanopia, which makes it difficult to judge colors accurately, so it is generally difficult to judge colors accurately when the viewing angle is less than 10'. I'm getting older. For example, if a printed matter is placed at a distance of clear vision (approximately 30 cm),
Slight differences in color between lines and dots separated by 800 μm or less are hardly noticeable. Therefore, as in the present invention, the color of dots that are generally separated by a distance of about one dot is not recognized, and the image is recognized as a uniform color image.

As is clear from the above description, according to this embodiment, the plurality of recording heads is further composed of a plurality of head groups that handle ink of different colors, and the plurality of recording head groups are alternately shifted in the paper conveyance direction. Because it adopts a configuration in which the dots are placed in parallel, it is possible to suppress color reversal for each dot within the above-mentioned recording width, and the simple structure allows for uniform color images and high-speed operation. An inkjet recording method can be provided.

The inkjet recording method of the present invention can form a recorded image as if it maintains substantially uniform color even when recording is performed each time the carriage moves back and forth, thereby preventing the size of the recording device from increasing. , it was possible to achieve a high-speed record.

[Brief explanation of the drawing]

Figures 1 and 2 explain the configuration and operation of a conventional inkjet recording method. Figure 1 is a perspective view showing the schematic configuration of a conventional image recording device, and Figure 2 is a diagram showing a schematic configuration of a conventional inkjet recording method. Explanatory diagrams for explaining the operation, FIG. 3 to FIG. 5 are for explaining the configuration and operation of the embodiment of the present invention.
The figure is an explanatory diagram for explaining a partial concept of a recording head applied to the inkjet recording method of the present invention.
FIG. 4 is a front view illustrating the structure of the recording section of the inkjet recording method of the present invention, and FIG. 5 is an explanatory diagram illustrating the operation of the inkjet recording method of the present invention. 3... Recording paper, 10... Recording head, 10
A, 10B...head unit, 10C...orifice.

Claims (1)

[Scope of Claims] 1. A carriage that carries an inkjet recording means and moves thereon, and a means that conveys the recording medium to be recorded at intervals of a predetermined recording width, and performs recording by both reciprocating movement of the carriage. In the inkjet recording method, the recording means includes a first jetting port group in which a plurality of jetting ports for jetting a first color ink are arranged at a predetermined pitch in a direction different from the recording direction; a second jetting port group having the same number of jetting ports for jetting ink as the jetting ports in the first jetting port group and offset at the pitch so as to complement each other; and a second jetting port group that jets the second color ink. a third injection port group having injection ports arranged at the pitch so as to correspond to each of the injection ports of the first injection port group, and having the same number of injection ports as the injection ports of the first injection port group; a fourth jetting port group including jetting ports for jetting colored ink arranged at the pitch so as to correspond to each jetting port of the second jetting port group, and having the same number of jetting ports as the jetting ports of the first jetting port group; , the first and second nozzle groups are provided with a first nozzle group and a third nozzle group.
The overlapping order of the color ink and the overlapping order of the second and first color inks by the second jetting port group and the fourth jetting port group are staggered according to the pitch within the predetermined recording width. An inkjet recording method characterized by recording.