JPH07195715A - Color inkjet printer - Google Patents

Abstract

(57) [Abstract] [Purpose] A color image is formed by scanning a print cartridge having a plurality of ink heads corresponding to the inks of yellow, magenta, cyan, and black in parallel in the width direction of the recording material. In a color ink jet printer capable of forming a color image, a printing speed can be shortened and a color image having no color error is formed. The print head 1 has a set of first and second ink heads X and Y arranged in the same color order for the forward and backward passes in the scanning direction. As the ink head, the ink head of the second set Y is used on the return path.

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 printer capable of forming a color ink image at a high speed.

[0002]

2. Description of the Related Art Among several methods known as non-impact printing technology, an inkjet method is known as one of the technologies that have been receiving attention in recent years. Inkjet systems are typically broadly classified as continuous jet type, intermittent jet type, and on-demand type according to the method of ejecting ink droplets, and depending on the ejecting means, bubble type,
Although it is classified as a piezo type or an electrostatic type, any type does not require steps such as fixing and cleaning because it is a method of directly ejecting ink droplets onto a recording material to form an image. It is useful as a hard output of a computer because it has an advantage that the structure of the device is simple and can form images of characters, figures, etc. freely according to a dot pattern.

The above-mentioned advantages of the ink jet system can be effectively used not only for monochrome images such as black and white prints but also for superimposing inks of respective colors, so that multicolor prints such as multicolor or full color prints can be made.

A conventionally known color ink jet printer has a print cartridge 100 in which four color ink heads of yellow, magenta, cyan, and black are arranged in parallel as shown in FIG.
The print head 100 is caused to scan in the width direction of the recording material, that is, in the direction of arrow A while being temporarily stopped at a predetermined interval. During this scanning, the image signals corresponding to each color of yellow, magenta, cyan, and black are sent from the computer or the document reading scanner to the ink heads of the corresponding colors, and the color image is formed by the dot pattern corresponding to each color. Form. Then the print cartridge is restored,
In the next scan again, a color image is formed.

[0005]

One of the problems in such a conventional printer is print speed. The print speed of an inkjet printer depends on various factors such as the number of nozzles of the head, the ejection frequency, the processing time of image signals, the feeding speed of recording materials and print cartridges, but it is still insufficient compared to other methods such as electrophotography. There is no speedup. In particular, in the above-mentioned conventional configuration, since the printing configuration is only for the forward scan path, it cannot be expected to increase the speed.

Therefore, it is an object of the present invention to provide a color ink jet printer capable of high speed color printing and not impairing the image quality.

[0007]

In order to solve the above problems, the color ink jet printer according to the present invention is
A color inkjet printer for forming a color image by scanning a print cartridge having a plurality of ink heads corresponding to inks of yellow, magenta, cyan, and black in parallel in a width direction of a recording material, wherein the print head Has a set of first and second ink heads arranged in the same color order for the forward and return passes in the scanning direction, the first set of ink heads for the forward pass and the second set of ink heads for the return pass. It is characterized by using the ink head.

In particular, the adjacent ink heads of the first and second sets are commonly used in the forward and backward passes.

[0009]

With such a construction, printing can be performed in both the forward and backward scanning directions, so that the printing speed can be shortened, and a set of forward and backward ink heads is provided to arrange the ink heads for each color. That is, since the color order is the same in the forward and backward sets,
A color image having no color error is formed between the printing on the outward path and the printing on the returning path. Normally, even if inks of the same color are superposed on each other, the colors become slightly different according to the superposition order, but this is solved by the configuration according to the present invention.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view showing a scanning unit of a print cartridge of an ink jet printer according to the present invention, and FIGS. 3 and 4 show different embodiments of a print cart jig used therein. The printing cart jig 1 is supported by two shafts 2 and 3 so as to be slidable in the axial direction of the shaft, and faces a recording material 5 such as paper set on a platen 4 at a constant interval. . The print cartridge 1 is scanned by the drive of the forward / reverse rotation motor 10 via the wire 9 stretched around the pulleys 6, 7, and 8. The sex reversing motor 10 rotates in the forward and reverse directions based on the signal instructing the forward and backward paths of the print cartridge, and conveys the print cartridge at a predetermined uniform speed in either direction. A position detecting means (not shown) is provided to detect the standby position or the scanning position of the print cartridge 1 and functions to generate a position signal for timing the start of printing or scanning.

The print cartridge 1 that can be preferably used in the present invention has a plurality of ink heads corresponding to the inks of yellow, magenta, cyan, and black in the same color order in the forward and backward passes in the scanning direction of the cartridge. Have a first and a second set arranged in. In the example shown in FIG. 2, the print cartridge 1 commonly uses a black ink head 11, and cyan 12, 16 and magenta 12, 16 and yellow that are color-aligned so as to be symmetrical about the head 11 are used. It has two sets of ink heads X and Y of 14 and 18, and X when the cartridge is going forward.
The set of yellow 14, magenta 13, cyan 12 and black 11 is in this order, and the set of Y is yellow 18, magenta 17, cyan 16 and black 11 in this order when the cartridge is returning. Print at the timing of. In the illustrated example, the black ink heads 11 are commonly used for the X group and the Y group.
Two black ink heads may be provided exclusively for the group.

Each of the ink heads 11 to 18 has substantially the same configuration except for the ink color, and is arranged in a line in the width direction of printing, that is, in the direction orthogonal to the scanning direction of the cartridge (vertical direction in FIG. 3). It has a plurality of ejection nozzles arranged in several rows, and the corresponding nozzle is selected according to the output from a computer or the like to eject ink dots. As the ink head system, a bubble type or a piezo type can be preferably used, but it is not limited to this.

In such a configuration, the feeding B of the recording material 20 is stopped at every predetermined width, but when stopped, the forward scan (set X) and the backward scan (set Y) are alternately performed, and the scan time is set. Try to shorten. That is, when the recording material 20 is stopped, the print cartridge 1 moves in the direction indicated by arrow A in FIG. 3 (forward direction).
When moving to, the set X prints. When the forward movement of the print cartridge is completed, the platen 4 rotates by a predetermined angle, conveys the recording material by a predetermined width, and stops again.
Prints.

FIG. 4 is a view showing another arrangement of the print cartridges. As shown in the drawing, the ink head groups are staggered in the feeding direction of the recording material. Is also good. In this case, since two-width printing can be performed in the reciprocation of the print cartridge, the recording material may be fed once for each reciprocation of the print cartridge.

[0015]

As described above, according to the present invention, printing is performed using the reciprocating path of the print cartridge, and the color overlapping order of the forward path and the returning path is invariable, so that the printing speed can be shortened and the color can be reduced. A color image with less error can be formed.

[Brief description of drawings]

FIG. 1 is an external view showing a scanning unit of a print cartridge of a color inkjet printer according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a conventional print cartridge.

FIG. 3 is an explanatory diagram showing a configuration of a print cartridge according to the present invention.

FIG. 4 is an explanatory diagram showing another configuration of the print cartridge according to the present invention.

[Explanation of symbols]

 1 Print cartridge 2,3 Shaft 11-18 Ink head

Claims (2)

[Claims] 1. A color inkjet printer that forms a color image by scanning a print cartridge having a plurality of ink heads corresponding to inks of yellow, magenta, cyan, and black in parallel in a width direction of a recording material. In the print head, the print head has a set of first and second ink heads arranged to have the same color order in the forward and backward passes in the scanning direction. At the second
A color ink jet printer characterized by using a set of ink heads. 2. The color inkjet printer according to claim 2, wherein the first and second sets of adjacent ink heads are commonly used in the forward and backward passes.