JPH0345351A - Color printer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a color printer capable of reciprocating color printing, such as a flat scanning color printer.

BACKGROUND OF THE INVENTION Recently, flat scanning color printers have come into widespread use as output terminals for office automation equipment and video information equipment. This printer has a reciprocally movable ejection head that ejects ink both forward and backward, allowing for reciprocating color printing, so the printing speed is fast.

A specific method of reciprocating color flint is known, for example, in Japanese Patent Laid-Open No. 75255/1983.

Hereinafter, two reciprocating color printing methods in a conventional flat scanning color printer will be described with reference to the drawings.

In the first reciprocating color printing method, as shown in Figure 3, the printer heads A, (Y-Yellow), B (
It has four ink ejection heads: M-magenta), c (c-cyan), and D (BK-black). Each of these heads A1B, C! , ]) are mounted on a single carriage (not shown) and can move back and forth, and each ejection head has N ejection nozzles. Recording paper (recording body) P is fed in the direction of arrow Y in the figure, while the ejection head is reciprocated in direction X perpendicular to the feeding direction Y of recording paper P.

In the past, the ejection head moved from left to right to perform ink ejection operations, and as shown in Figure 4, N947 color prints were made. When the previous color printing is completed, the recording paper is advanced by N lines, and the next color printing is started. When returning, the ejection head performs ink ejection operation while moving from right to left, and as shown in Figure 4, N94
Make a 7 minute color print.

Next, the second reciprocating color printing method will be explained.

In the second color printing method, the spacing between the ejection nozzles at each person's nozzle A-D was set to a pinch interval that was twice the print line pitch (1/2 the density), and in the past, the ejection head was moved from left to right. 1 as shown in Figure 6.
Color printing for N947 is performed at line intervals, that is, at 1/2 the conventional density. When the previous color printing is completed, the recording paper P is fed by one line, and the backward color printing begins. When returning, the ejection head is moved from right to left, and as shown in FIG. 6, color printing is performed on the intermediate line N917 of the previous print.

61\-7 Problems to be Solved by the Invention However, in the case of the first method, the overlapping order of ink is reversed between forward and backward printing, so there is a gap between the printing surface of the forward printing and the printing surface of the backward printing. There is a problem that there is a noticeable difference in color tone.

In the case of the second latter method, the forward print line and the backward print line alternate line by line, so the difference in tone between the former print surface and the backward print surface becomes less noticeable, but the same nozzle prints. Since the print I lines run adjacent to each other in parallel, there is a problem in that quality deterioration due to variations in the amount of ink ejected between nozzles is doubled.

In view of these circumstances, the present invention has developed a reciprocating color printing method that eliminates color tone differences due to differences in the direction of ejection head movement during forward and return times without increasing quality deterioration due to variations in ink ejection amount. Our goal is to provide a color printer.

Means for Solving the Problems In order to solve the above problems, the color printer according to claims 1 to 3 is provided with a plurality of reciprocally movable ejection heads that eject seven-color ink corresponding to each of a plurality of colors, These ejection heads are arranged so that they can eject ink in the same color order both during forward and backward movement.

The color printer according to claim 2 is further provided with two ejection heads each ejecting ink of the same color, one of each of the two ejection heads is a first ejection head group, and the other is a second ejection head group. They are organized so that only the first ejection head group performs the ejection operation in the past, and only the second ejection head group performs the ejection operation in the return.

In addition, the color printer according to claim 3 is further provided with two ejection heads each ejecting ink of the same color, and of each of the two ejection heads, one of the first ejection head group and the other one of the second ejection head group are distributed. Both groups perform the ejection operation both in the forward and backward directions.

Furthermore, in order to solve the above problem, the color printer according to claims 4 to 6 is provided with a plurality of reciprocating ejection heads that eject ink corresponding to each of a plurality of colors, and each of these ejection heads has the following features: A plurality of ejection nozzles are arranged along the recording medium transport direction so as to simultaneously print multiple print lines on the recording medium, and these nozzles eject ink in different color orders on adjacent print lines. It is designed to do this.

The color printer according to claim 6 is further provided with two ejection heads each ejecting ink of the same color, and each of the two ejection heads is organized into a first ejection head group on one side and a second ejection head group on the other side. Each of the ejection heads in both groups has a number of nozzles corresponding to each print line, but in one ejection head group, only the nozzles corresponding to every other selected print line perform an ink ejection operation. In the other ejection head group, only the nozzles corresponding to the unselected print lines perform ink ejection operations.

In the color printer according to claim 6, in addition, 9 h-
Each ejection head is equipped with two ejection heads that eject ink of the same color, and one of each of the two ejection heads is organized into a first ejection head group, and the other ejection head is organized into a second ejection head group. The ejection heads of the head group have nozzles arranged only at positions corresponding to odd-numbered print lines, and the ejection heads of the second ejection head group have nozzles arranged only at positions corresponding to even-numbered print lines. ing.

In the color printer according to the first to third aspects of the invention, since the ink ejection order is the same in the forward printing and the backward printing, the difference in tone between the forward printing surface and the backward printing surface is eliminated. Moreover, since there is no situation where lines printed by the same nozzle are adjacent to each other, there is no situation where variations in the amount of ink ejected from the nozzles are accentuated and the quality deteriorates.

In the color printer according to claims 4 to 6, since the ink ejection order of adjacent print lines is different on each of the forward and backward print surfaces, there is no difference in color tone between the forward print surface 10/\- and the backward print surface. is resolved. Moreover,
Since lines printed by the same nozzle are not adjacent to each other, there is no situation where variations in the amount of ink ejected from the nozzles are accentuated and quality deteriorates.

Embodiment Hereinafter, a color printer according to the present invention will be explained in detail based on an embodiment thereof.

Embodiment 1 FIG. 1 shows the configuration around the ejection head in a plane scanning color printer of Embodiment 1.

As shown in FIG. 1, the printer head of Example 1 has 8
two ejection heads, S1 (i.e., ejection heads 11-A, (
yellow), ejection head 13-B (magenta), ejection l
Head l6-C (cyan), ejection head 17-D (black), ejection head 18-A (yellow), ejection head 1e-B (magenta), ejection head l4-C (cyan)
, a discharge head 12D (black), and each head is mounted on one carriage (not shown) and is movable back and forth. The eight ejection heads each have N ejection nozzles (1 to N) arranged in a direction Y perpendicular to the reciprocating direction X, and are arranged along the reciprocating direction X in the order illustrated.

Then, in the ejection head 11.13.15.17, the first ejection head group is the ejection head 12.14.16.18.
A second ejection head group is organized in such a manner that only the first ejection head group performs ejection operation in the past, and only the second ejection head group performs ejection operation during return.

In the past, as the head moved, only the first ejection head group performed the ejection operation and printed for N947. In the past, the ejection color order was A-B→C→D. When past printing is completed, the recording paper P is moved by a recording paper feeding means (not shown) by N947 minutes (N dots), so that the unprinted surface is under the ejection head.

At the time of return, only the second ejection head group performs ejection operation as the head moves backward, and prints for N947 are performed. Also in the case of return, the ejection color order is A-B-C-D.

Ink is ejected in the same color order both in the forward and backward directions. Therefore, it is possible to perform high-quality color printing in which the difference in tone between the previously printed surface and the previously printed surface is eliminated.

Of course, once the return printing is completed, the recording paper P'h is
Needless to say, the recording paper is moved by a recording paper feeding means (not shown) by "-N lines, and the unprinted surface comes under the ejection head, and the previous printing is repeated.

Note that the grouping of the first and second ejection head groups is not limited to the above. It is sufficient that the order of ejected colors be the same both in the forward and backward directions. For example, the first ejection head group
With the ejection heads 11.12.13.14, a second ejection head group may be formed with the ejection heads 16.16.17.18. As expected, the ejected color order is A during both the forward and return times.
-) D-B-+C! is the same as

Embodiment 2 The configuration around the ejection head in the plane scanning color printer of Embodiment 2 is the same as 13 shown in FIG. 1, and is the same as that of Embodiment 1.

Then, in the ejection head 11.13.16.17, the first ejection head group is the ejection head 12.14.16.18.
The second ejection head group is organized in the first and second ejection head groups.
The second ejection head group performs ejection operations both in the forward and backward directions. However, compared to the case of the first embodiment, the ejection amount for each head is half.

In the past, as the heads moved, both ejection head groups performed ejection operations to print for N947. In the past, the ejection color order was A +]) -+ 13→C-4C→
B-1D→A-. When past printing is completed, the recording paper P is moved by N947 minutes (N dots) by a recording paper feeding means (not shown), so that the unprinted surface is under the ejection head.

During the return, both ejection head groups also perform ejection operations to print for N947. Even in the case of return, the ejection color order is A-D-B-C! →C→BD→A, so the colors are ejected in the same order both in the forward and backward directions. therefore,
High-quality color prints can be made in which the difference in color tone between the previously printed surface and the previously printed surface has been eliminated.

In order to halve the ejection amount of each head, the pulse width may be controlled so that two heads of the same color produce the ejection amount of one head in Example 10. In this case, since the pulse width is halved, color printing can be performed at a speed 2 times faster than in Example 10. Compared to a one-way color printing method using only the first ejection group, color printing can be performed at four times the speed.

In the case of a color printer like Embodiment 2, the ejection head arrangement is not limited to that shown in FIG.
C! A discharge head arrangement such as -B-A may also be used. Of course, the ejection color order is A-+B→C→D→D both forward and backward.
→C→B→A.

Embodiment 3 The configuration around the ejection head in the plane scanning color printer of Embodiment 3 is as shown in FIG. 1, and is the same as that of Embodiment 1.

Then, the first ejection head group is the ejection head 11.13.16.1a, and the ejection head 12.14, 16 ・\
-2 A second ejection head group is formed by 16 and 18, and the first and second ejection head groups perform ejection operations both during forward and return operations.

However, in the heads of the first ejection head group, only the odd numbered nozzles out of N nozzles perform the ejection operation, and in the heads of the second ejection head group, only the even numbered nozzles out of the N nozzles perform the ejection operation. .

First, after performing previous printing, the recording paper P is moved by N947 minutes (N tons) using a recording paper feeding means (not shown), and the unprinted surface is brought under the ejection head. Print.

In this case, there are print lines with the ejected color order A-B-0-D and print lines with the ejected color order D-C-B→A both during the forward and return times, but they are scattered and mixed throughout. Therefore, the difference in color tone is not noticeable when looking at the print surface of the entire N lines, and since the print lines by the same nozzle are not lined up, the influence of the variation in the ejection amount of the nozzles is not magnified.

Note that when reversing from the previous time to the return time, the heads of the first ejection head group perform the ejection operation with only an even number of the N nozzles, and the heads of the second ejection head group perform the ejection operation of the N nozzles. Only the odd-numbered nozzles may perform the ejection operation, and the nozzles used in each head may be switched between forward and backward operations.

Embodiment 4 FIG. 2 shows the configuration around the ejection head in a plane scanning color printer of Embodiment 4.

As shown in FIG. 2, the printer head of Example 4 has 8
three ejection heads, namely ejection head 21-man (yellow), ejection head 23-B (magenta), ejection head 26-c (cyan), and ejection head 2-D (black).
, ejection head 28-A (yellow), ejection head 26-
13 (magenta), a discharge head 24-C (cyan), and a discharge head 22D (black), each head is mounted on one carriage (not shown) and can be moved back and forth. There is. Each of the eight ejection heads has N ejection nozzles (1 to N) arranged in a direction Y perpendicular to the reciprocating direction They are arranged in the order shown.

Then, in the ejection head 21.23.26.27, the first ejection head group is the ejection head 22.24.26.28.
A second ejection head group is formed, and both ejection head groups perform ejection operations both during forward and return operations. However, as shown in Figure 2, the ejection heads of the first ejection head group have nozzles arranged only at positions corresponding to odd-numbered print lines, and the ejection heads of the second ejection head group have nozzles arranged only at positions corresponding to even-numbered print lines. Nozzles are placed only in corresponding positions.

First, after performing previous printing, a recording paper feeding means (not shown) moves the recording paper P by 2N lines (NFy l□ minutes).
to bring the unprinted surface under the ejection head and perform return printing.

In this case, both forward and backward, the print line has a discharge color order of A-to 13-) 0-→D, and D-C→B→A and 18
There are print lines with the same ejected color order as 1\-/, but they appear alternately every other line and are scattered and mixed throughout, so when looking at the overall 2N lines, the difference in color tone fades, and moreover, Since the print lines from the nozzles are not lined up, the effects of variations in the ejection amount of the nozzles are not magnified. Since 2N lines are printed in one direction, the printing speed is four times that of one-way printing.

Note that the color printer according to the present invention may be a single color printer having a configuration in which, for example, the three reciprocating color printing methods of Examples 1 to 30 can be switched.

Effects of the Invention As described above, in the color printer according to claims 1 to 3, since the ink ejection order is the same in the forward printing and the backward printing, there is a difference in color tone between the forward printing surface and the backward printing surface. Since the difference is eliminated and the print lines of the same nozzle are not adjacent to each other, there is no possibility that the variation in the amount of ink ejected from the nozzles will be accentuated and the quality will deteriorate. It is also possible to print at a speed 2 to 4 times faster than normal one-way printing.

In the color printer according to claims 4 to 6, since the ink ejection order of adjacent print lines is different on each of the forward and backward printing surfaces, the difference in tone between the forward printing surface and the backward printing surface is eliminated.

Furthermore, since adjacent print lines from the same nozzle do not occur, there is no situation where variations in the amount of ink ejected from the nozzles are accentuated and quality deteriorates. It is also possible to print at a speed 2 to 4 times faster than normal one-way printing.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram schematically showing the configuration around the ejection head of a flat scanning color printer according to Examples 1 to 3 of the present invention, and FIG. FIG. 3 is an explanatory diagram schematically showing the configuration around the ejection head of a printer. FIG. 3 is an explanatory diagram schematically showing the configuration around the ejection head of a conventional flat scanning color printer. FIG. 6 is an explanatory diagram of a reciprocating color printing method of a color printer. FIG. 6 is an explanatory diagram of a reciprocating color printing method of another conventional color printer. 11.13.15.17...Ejection head of the first ejection head group, 12.14.16.18...Ejection head of the second ejection head group, 21.23.26.27
...Ejection head of the first ejection head group, 22.2
4.26.28... Ejection head of the second ejection head group, P... Recording paper (recording body).

Claims (6)

[Claims] (1) Equipped with a plurality of reciprocating ejection heads that eject ink corresponding to each of a plurality of colors, and these ejection heads are arranged so that they can eject ink in the same color order during forward and return travel. color printer. (2) Two ejection heads that eject ink of the same color are provided, and one of each two ejection heads is organized into a first ejection head group and the other is organized into a second ejection head group. 2. The color printer according to claim 1, wherein only the ejection head group performs the ejection operation, and when returning, only the second ejection head group performs the ejection operation. (3) Two ejection heads that eject ink of the same color are provided, one of each of the two ejection heads is organized into a first ejection head group, and the other is organized into a second ejection head group, and both groups are arranged together. 2. A color printer according to claim 1, wherein the ejection operation is performed both during forward and backward movement. (4) Equipped with a plurality of reciprocating ejection heads that eject ink corresponding to each of a plurality of colors, and each of these ejection heads has a plurality of ejection nozzles so as to simultaneously print multiple print lines on a recording medium. A color printer in which the nozzles are arranged along the recording medium transport direction, and these nozzles perform ink ejection operations in different color orders on adjacent print lines. (5) Two ejection heads that eject ink of the same color are provided, one of each of the two ejection heads is organized into a first ejection head group, and the other is organized into a second ejection head group, and each of the two groups The ejection head has a number of nozzles corresponding to each print line, but in one ejection head group, only the nozzles corresponding to every other selected print line perform ink ejection operation, and in the other ejection head group, only the nozzles corresponding to the selected print line perform ink ejection operation. 5. The color printer according to claim 4, wherein only the nozzles corresponding to the print lines that have not been printed perform an ink ejecting operation. (6) Two ejection heads each ejecting ink of the same color are provided, one of each of the two ejection heads is organized into a first ejection head group, the other ejection head is organized into a second ejection head group, and the second ejection head group is formed with the other ejection head. In the ejection heads of the first ejection head group, nozzles are arranged only in positions corresponding to odd-numbered print lines, and in the ejection heads of the second ejection head group, nozzles are arranged only in positions corresponding to even-numbered print lines. A color printer according to claim 4.