JPH1148503A - Ink jet recording head and ink jet recording apparatus - Google Patents

Abstract

(57) Abstract: An ink jet recording head for selectively performing recording only during forward movement and reciprocating recording using inks of a plurality of colors, and a superposition of color inks in a recording apparatus equipped with the head. Reduce color difference due to order. The ink jet recording head includes nozzle rows in which nozzles for ejecting inks of respective colors are arranged at equal intervals in the sub-scanning direction. When the number of ink colors is I, the interval between the nozzles in the sub-scanning direction is equal to the number of pixels. The pitch is I × α (α is a positive integer) times, and the position of the nozzle row in the sub-scanning direction is different for each color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head and an apparatus for recording an image by alternately performing main scanning and sub scanning of an ink jet recording head, and in particular, recording only at the time of forward movement using a plurality of color inks. The present invention relates to a color ink jet recording head and an apparatus for performing selective recording and reciprocating motion recording.

[0002]

2. Description of the Related Art As shown in FIG. 7, for example, as shown in FIG. 7, an ink jet recording apparatus which performs recording using inks of a plurality of colors has a nozzle in which a plurality of nozzles for discharging ink are arranged in a sub-scanning direction. A row is configured for each color ink. An image is recorded on a recording medium by alternately repeating main scanning and sub-scanning with this ink jet recording head. Further, multicolor images can be recorded by overlapping different color inks on the same position on the recording medium.

In Japanese Patent Publication No. 3-76226, there is disclosed a method for preventing bleeding due to superposition of color inks and a color tone difference by reversing the superposition order of color inks when reciprocating recording is performed in the main scanning direction. A recording device as shown in FIG. In each color nozzle row, N nozzles are arranged at intervals of K times the pixel pitch in the sub-scanning direction, and the positions of the nozzle rows of each color in the sub-scanning direction are shifted by L times the pixel pitch. Sub-scan is performed N times the pixel pitch per scan. At this time, K and N are disjoint, and by setting L = α × N (α is a positive integer), even when reciprocating printing is performed, the overlapping order of the color inks is always constant. Becomes

[0004]

In the above-described ink jet recording apparatus, the order of superimposing the colors is always constant, so that the order of superimposing the colors determined by the arrangement of the nozzle rows must be determined as one. This is a difficult task in consideration of a color tone difference due to the order of superimposition of colors when different recording media are used. Further, the position of the nozzle row of each color in the sub-scanning direction is represented by L = α ×
Since it is necessary to displace the nozzles by N times, when the number N of nozzles increases, the size of the recording head in the sub-scanning direction increases.

[0005]

In order to solve the above-mentioned problems, the present invention is mounted on an ink-jet recording apparatus for selectively performing recording only during forward movement and reciprocal movement recording using inks of a plurality of colors. The ink jet recording head includes a nozzle array in which nozzles for ejecting each color ink are arranged at equal intervals in the sub-scanning direction.
The interval of the nozzles in the sub-scanning direction is I × α (α is a positive integer) times the pitch of the pixels recorded on the recording medium, and the position of the nozzle row in the sub-scanning direction is different for each color. It is characterized by. In addition, the ink jet recording apparatus equipped with the head performs the sub-scan feed of one pixel or more for each main scan, and discharges the ink such that different color inks of the respective colors overlap the same pixel. Is controlled. Further, when the number of nozzles in the nozzle row of each color is N, the printing apparatus sets the moving amount of the sub-scanning after the main scanning of the ink jet printing head to N times the pixel pitch, and N and I × α (α is (Positive integer) are mutually prime.

[0006]

Embodiments of the present invention will be described in detail below. A recording device according to an embodiment of the present invention will be described. FIG. 1, FIG. 2 and FIG. 3 show the structure of a recording apparatus showing an embodiment of the present invention. A recording medium 1 such as paper or film is driven by a sub-scanning motor 2 via a pinion gear 3 and a gear 4. Transported to The carriage 8 is fixed to a belt 10 at a connection portion 9. The belt 10 includes a main scanning motor 11, a driving pulley 12 for transmitting the rotation of the main scanning motor 11, and a driven pulley 13 that rotates in conjunction with the driving pulley to form a carriage driving unit.
The carriage 8 is moved in the main scanning direction 14 by the rotation of the main scanning motor 11. Further, the carriage 8 includes an ink tank 15 corresponding to a plurality of color inks, an ink supply path 16, and an ink jet recording head 17 having a nozzle row 18 having a plurality of nozzles for ejecting ink droplets on the recording medium 1. Is done. Some ink jet recording heads 17 generate ink pressure by vibrating a piezoelectric vibrator to discharge ink, and others use a heating element to heat ink to foam and discharge ink by the expansion pressure. Although there is a system, any type of ink jet recording head can be used in the present invention.

[0007] These ink jet recording heads 17
And the main scanning motor 11 and the sub scanning motor 2 are CP
An image is output based on data transmitted from a host 20, such as a computer, under the control of a control unit 19 composed of U, RAM, ROM and the like. At this time, host 2
The recording from only the forward movement and the reciprocating movement recording are selected and executed by the signal from 0.

FIG. 4 shows an example of the arrangement of the nozzle rows 18 of the ink jet recording head 17 according to the first embodiment of the present invention. This is an ink jet recording head using four color inks of Bk, Y, M, and C. Each of the nozzles ejects each color ink has N nozzles, and the interval in the sub-scanning direction is I × α times the pixel pitch ( α is a positive integer and I is the number of ink colors. In FIG. 4, N = 3, I = 4, and α = 1. Further, the positions of the nozzle rows of each color in the sub-scanning direction are all located at different positions shifted by one pixel pitch.

Using such an ink jet recording head, the amount of sub-scanning movement per main scanning is set to N times the pixel pitch, and in the sub-scanning direction where N and α × I are mutually prime. When pixels are printed while repeating the movement for each main scan, the superposition order of the color inks on the print medium changes for each line in the main scan direction, as shown in FIG. In addition, since the order of superimposition of colors is determined by the position of the nozzle row of each color and the amount of sub-scanning movement, it does not depend on the direction of main scanning, and does not change even when reciprocating recording is performed.

FIG. 6 shows an example of an arrangement of nozzle rows 18 of an ink jet recording head 17 according to a second embodiment of the present invention. The nozzles for ejecting the four color inks of Bk, Y, M, and C are sequentially arranged in one row in the sub-scanning direction. Assuming that a nozzle row is formed for each color, N = 3, I = 4,
Since α = 1 and the same as FIG. 4, if the moving amount of the sub-scan per one main scan is set to N times the pixel pitch, the same recording state as in FIG. 5 can be obtained. By using this embodiment, it is possible to further reduce the size in the main scanning direction of the ink jet recording head that can obtain the same effect as that of the first embodiment.

In the embodiment of the present invention, the case where the number of colors of ink is I = 4 has been described. However, it is possible to form a nozzle array which can obtain the same effect even with an ink jet recording head having an arbitrary number of colors. It is.

[0012]

As described above, in the ink jet recording apparatus of the present invention, since the superposition order of the color inks changes for each line in the main scanning direction, the color difference due to the superposition order of the colors is dispersed and the image quality is improved. improves. In addition, since the positions of the nozzle rows of each color in the sub-scanning direction may be shifted by at least one pixel pitch, an ink jet recording head in which the order of superimposition of colors does not change even when reciprocating recording is performed can be realized with a small size.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a recording apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram of a recording head showing an embodiment of the present invention.

FIG. 3 is a block diagram of a recording apparatus showing an embodiment of the present invention.

FIG. 4 is a diagram showing a nozzle row according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a recording state according to the embodiment of the present invention.

FIG. 6 is a diagram illustrating a nozzle row according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a conventional nozzle array.

FIG. 8 is a diagram showing a conventional nozzle array.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 recording medium 2 sub-scanning motor 3 pinion gear 4 gear 5 driving roller 6 holding roller 7 sub-scanning direction 8 carriage 9 connecting portion 10 belt 11 main scanning motor 12 driving pulley 13 driven pulley 14 main scanning direction 15 ink tank 16 ink supply path 17 Inkjet recording head 18 Nozzle group 19 Control means 20 Host

Claims (3)

[Claims] In an ink jet recording head mounted on an ink jet recording apparatus for selectively performing recording only during forward movement and reciprocal movement recording using inks of a plurality of colors, a nozzle for discharging each color ink to the head is provided. The nozzle array is provided at equal intervals in the sub-scanning direction, and when the number of ink colors is I, the interval between the nozzles in the sub-scanning direction is I × α (α is a positive value) of the pixel pitch recorded on the recording medium. ) Times
An ink jet recording head, wherein the position of the nozzle row in the sub-scanning direction is different for each color. 2. An ink jet recording head according to claim 1, wherein one or more sub-scan feeds are performed for each main scan, and different color inks of the respective colors overlap the same pixel. An ink jet recording apparatus for controlling ejection of the ink. 3. When the number of nozzles of a nozzle row of each color is N, the amount of movement of the sub-scan after the main scan of the ink jet recording head is N times the pixel pitch, and N and I × α (α is a positive value). 3. The ink jet recording apparatus according to claim 2, wherein (integer) is mutually prime.