JP3248704B2 - Color inkjet printer - Google Patents

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 systems known as non-impact printing technologies, an ink-jet system is known as one of the technologies that have been receiving attention in recent years. Ink jet systems are typically classified in a broad sense as a continuous ejection type, an intermittent ejection type, or an on-demand type according to the method of ejecting the ink droplets, and a bubble type,
It is classified into a piezo type and an electrostatic type. In either type, since the image formation is performed by ejecting small ink droplets directly on the recording material, there is no need for fixing, cleaning and other processes. It has the advantage that the configuration of the device is simple, and is useful as a hard output of a computer because images such as characters and figures can be freely formed according to a dot pattern.

The above advantage of the ink-jet method is effective not only for monochrome images such as black-and-white printing but also for multi-color printing such as multi-color printing or full-color printing because ink of each color can be easily superimposed.

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

[0005]

One of the problems in such a conventional printer is the printing speed. The printing speed of an inkjet printer depends on various factors such as the number of nozzles and ejection frequency of a head, the processing time of an image signal, the feeding speed of a recording material and a print cartridge, but is still insufficient compared with other methods such as an electrophotographic method. Speed has not been achieved. In particular, in the above-described conventional configuration, a high-speed printing cannot be expected because the printing configuration is performed only at the time of forward scanning.

[0006] Therefore, an object of the present invention is to provide a color ink jet printer capable of high-speed color printing and not impairing image quality.

[0007]

In order to solve the above problems, a color ink jet printer according to the present invention is provided.
Stopping of recording material for recording material sent intermittently at a specified width
Sometimes, in a color inkjet printer that forms a color image by scanning a print cartridge having a plurality of ink heads corresponding to inks of respective colors of yellow, magenta, cyan, and black in parallel in a width direction of a recording material, printhead, the set of first and second ink heads arranged such that the same color order with respect to forward and backward scanning direction a plurality of sets, these
When a plurality of sets of the first and second ink heads are transferred to the recording material,
The first set of ink heads on the outward path and the second set on the return path.
Scan using a set of ink heads and print cartridges
Wherein the first feed to Rukoto the recording material to one reciprocation of.

[0008]

[0009]

In such a configuration, printing can be performed in both the forward and backward directions of scanning, so that the printing speed can be reduced. In addition, a set of forward and backward ink heads is provided, and the arrangement order of the ink heads of each color is provided. That is, because the color order was the same in the forward set and the return set,
A color image having no color error is formed between printing on the forward path and printing on the return path. Normally, even if inks of the same color are superimposed, a slightly different color is obtained according to the superimposition order. However, 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 portion 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 cartridge used therein. The printing cartridge 1 is slidably supported in the axial direction of the shafts by two shafts 2 and 3, and faces a recording material 5 such as paper set on a platen 4 at a predetermined interval. . The print cartridge 1 is scanned by a forward / reverse rotation motor 10 via a wire 9 stretched over pulleys 6, 7, and 8. Forward and reverse <br/> rotation motor 10 is forward of the print cartridge, and forward and reverse rotation on the basis of a signal indicating a return, also conveys the print cartridge at a predetermined uniform rate in either direction. A position detecting means (not shown) is provided for detecting a standby position or a scanning position of the print cartridge 1, and serves to generate a position signal for setting a timing of starting printing or scanning.

In the print cartridge 1 which can be suitably used in the present invention, a plurality of ink heads corresponding to yellow, magenta, cyan and black inks are arranged in the same color order with respect to the forward and backward paths in the scanning direction of the cartridge. Has a first and a second set arranged in a row. In the example shown in FIG. 3 , the print cartridge 1 uses a black ink head 11 in common, and cyans 12, 16 and magenta arranged in color so as to be symmetrical with respect to the head 11 as a center. 13 , 17 and yellow 14 and 18, two sets of ink heads X and Y are provided.
Are set in the order of yellow 14, magenta 13, cyan 12, and black 11, and when the cartridge returns, the set of Y is set in the order of yellow 18, magenta 17, cyan 16, and black 11 while the cartridge is moving. The operation is performed at the timing shown in FIG. In the illustrated example, the black ink head 11 is common to the X group and the Y group.
Two black ink heads may be provided exclusively for the set.

Each of the ink heads 11 to 18 has substantially the same configuration except for the color of the ink, and is arranged in a row or several rows in a printing width direction, that is, a direction orthogonal to the scanning direction of the cartridge (vertical direction in FIG. 3 ) . , And a corresponding nozzle is selected according to an output from a computer or the like, and ink dot ejection is performed. As a method of the ink head, a bubble type or a piezo type can be preferably used, but the present invention is not limited thereto.

In such a configuration, the feeding B of the recording material 20 is stopped at every predetermined width, but at the time of stopping, the forward scan (set X) and the return scan (set Y) are performed alternately, and the scanning time is shortened. To shorten the time. That is, when the recording material 20 is stopped, the print cartridge 1 is moved in the direction indicated by arrow A in FIG.
The set X performs printing when moving to. 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, stops again, the forward / reverse rotation motor 10 rotates in reverse, the print cartridge 1 moves in the backward direction, and the set Y
Performs printing.

FIG. 4 is a view showing another arrangement of the print cartridges. As shown in the drawing, the sets of ink heads are provided alternately so as to be staggered in the recording material feed direction. Is also good. In this case, since printing in two widths can be performed in the reciprocation of the print cartridge, the recording material need only be fed once for one reciprocation of the print cartridge.

[0015]

As described above, according to the present invention, printing is performed by using the reciprocating path of the print cartridge, and the order of color superimposition on the forward path and the return path is not changed. A color image with few errors can be formed.

[Brief description of the 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 illustrating 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]

 DESCRIPTION OF SYMBOLS 1 Print cartridge 2-3 Shaft 11-18 Ink head

Claims (1)

(57) [Claims] 1. A recording medium which is intermittently fed at a predetermined width.
When the recording material stops, yellow, magenta, cyan,
In a color inkjet printer that forms a color image by scanning a print cartridge having a plurality of ink heads corresponding to black inks in parallel in the width direction of a recording material, the print head includes:
Multiple sets of the first and second ink heads arranged so as to have the same color order with respect to the forward path and the backward path in the scanning direction are used.
A plurality of these first and second ink heads
Pairs of papers to enable two-width printing in the recording material feed direction.
In the difference , the first set of ink heads
Scanning on the return path using the second set of ink heads ,
The recording material is sent once for one reciprocation of the print cartridge.
Color ink jet printer, characterized in squirrel Rukoto.