JPH0358855A - Printing method of serial printer - Google Patents

Abstract

PURPOSE:To perform high quality printing at high speed by a method wherein the number of printing elements in a printing head is set to be an odd number, the pitch between respective printing elements is set to be an even multiple which is not the multiple of the number of printing elements between adjoining lines to be practically printed and further, the paper feed pitch is set to be the multiple of the number of printing elements between the adjoining lines. CONSTITUTION:The number of printing element in a printing head 5 is set to an odd number, and the pitch among respective printing elements is set to an even number which is not the multiple of the printing elements arranged in the pitch between adjoining lines to be practically printed. Further, the paper feed pitch is set to the multiple of the number of printing elements arranged in the pitch between the adjoining lines. Thereby, a plurality of lines can be simultaneously printed through unilateral printing operation and in the case where bilateral printing is performed, each line is never superimposed on each printing element and printing can be performed so that the printing direction is reversed line by line. Then, printing speed can be increased and printing can be effectively performed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a serial printer number printing method, and in particular, to a method for printing serial printer numbers, in particular, it is possible to print in both directions, to improve printing quality, to easily control, and to significantly increase printing efficiency. This article relates to a printing method for a serial printer.

(Prior Art) Serial printers that perform bidirectional printing have been widely used in inkjet printers, wire dot printers, and the like.

If such a serial printer is an inkjet printer, for example, a carriage is provided that can freely move back and forth along a platen that feeds paper, a print head with a nozzle is mounted on this carriage, and this carriage is attached to the platen. While reciprocating along the paper, ink droplets are ejected from the nozzles of the print head and landed on the paper based on a desired print signal, thereby performing desired printing. In this case, when performing bidirectional printing, a print signal is generated when the carriage position is the same in the forward and backward directions, but the print head drive circuit is After receiving the print signal, the carriage moves during the time from when the ink droplets are ejected from the nozzles until they land on the paper, and the printing position shifts by that amount. The number of landing positions of ink droplets during backward printing changes. In addition, in color printers that perform color printing by sequentially overlapping ink of multiple colors, the nozzles for each color of ink are arranged in parallel, so the order of printing of each color changes depending on the printing direction. Characteristics change.

Therefore, the print head is equipped with multiple dot nozzles to continuously print multiple lines in the forward direction.
In the case of a printing device that continuously performs printing in a plurality of lines in the backward direction, there is a problem in that the vertical lines appear shifted or the print density appears to change at the portion where the printing direction is reversed.

In addition, in the case of color printing in which multiple colors are printed sequentially, the color tone differs depending on the printing direction, and the surface to be printed with the same color appears to be painted periodically with the border of the area where the printing direction is reversed. There was a problem that the printing quality deteriorated.

Conventionally, in order to solve such problems, there is a method of performing all printing in one direction. However, while it is easy to ensure printing quality with this method, the printing speed is lower than that of bidirectional printing, and it is necessary to use a print head with a faster response speed to obtain the same printing speed. In addition, it is necessary to increase the number of printing elements in the print head, resulting in a problem that the print head becomes extremely expensive.

Therefore, from the past. In order to make periodic printing unevenness less noticeable when bidirectional printing is performed, printing means is used that reverses the printing direction for each line.

Figure 8 shows such a conventional printing means.The print head is equipped with one nozzle, and this nozzle performs forward printing to print one line, and then prints one dot on the paper. Perform feeding, perform backward printing, and print the next one.
By printing lines and sequentially repeating this operation, desired printing is achieved.

In this type of printing means, since printing is performed in both directions, there is no wasted movement of the carriage, and since the landing positions of ink droplets ejected from the nozzles alternate for each line, they are averaged. Therefore, printing unevenness can be reduced.

However, since the printing means performs printing using one nozzle, the printing speed is extremely slow even when the driving frequency of the print head is increased, making it impractical.

Therefore, as shown in Fig. 9, four nozzles are provided in the print head at a two-dot pitch, and each nozzle allows
After printing the O line, 2nd line, 4th line, and 6th line by printing in the column direction, advance the paper by 1 dot, and then print in the backward direction to print the 1st line, 3rd line, and 5th line. And 7 lines of printing are performed. Next, the paper is fed by the number of printing elements x 2-1 dots (in this case, 7 dots), and the above operation is repeated again to perform the desired printing.

(Problem to be Solved by the Invention) However, in the printing method of the conventional serial printer, since multiple nozzles are provided, multiple lines can be printed by printing operation in one direction, and the printing speed is However, since the paper feeding pitch is not constant, it is extremely difficult to control the paper feeding rate, and it is difficult to maintain the precision of the paper feeding base with high precision.

The present invention has been made in view of these points, and when performing bidirectional printing, while maintaining high printing quality,
It is an object of the present invention to provide a printing method for a serial printer that can easily control paper feed and maintain high paper feed accuracy.

[W for the assignment? means to decide]

In order to achieve the above object, a printing method for a serial printer according to the present invention includes the steps of: reciprocating a print head in which a plurality of dots of print elements are formed on a print head that can reciprocate along a platen; In a printing method for a serial printer that performs bidirectional printing at a predetermined paper feed pitch, the number of printing elements of the print head is an odd number, and the pitch between each printing element is set to the pitch between adjacent lines that are actually printed. The printing is performed by setting the number of printing elements to an even number that is not a multiple of the number of printing elements, and further setting the paper feeding pitch to the number of printing elements times the pitch between adjacent lines.

[For production]

According to the present invention, the number of printing elements of the print head is an odd number,
The pitch between each printing element is an even number that is not a multiple of the number of printing elements of the pitch between adjacent lines actually printed, and the paper feed bit is set to be the number of printing elements times the pitch between the adjacent lines. Therefore, it is possible to print multiple lines at the same time by a single printing operation, and when printing in both directions, each printing element prevents each line from overlapping, and each line can be printed simultaneously. Since printing can be performed in opposite directions to each other, printing speed can be increased and printing can be performed efficiently. In addition, since the print dots printed by the printing element are different for each line, the position of each dot is averaged, reducing uneven printing and improving print quality.Furthermore, the paper feed pitch is always constant. Therefore, the paper feed can be easily performed, and the paper feed amount can be maintained with high accuracy.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 7.

FIG. 1 shows an embodiment of the printing method of a serial printer according to the present invention, in which five marks are formed at a pitch of 2 dots, and the paper feed pitch is set at 5 dots. , the number of printing elements in the print head is an odd number,
The pitch between the printing elements is an even number multiple of the pitch between adjacent lines actually printed, and the even number is not a multiple of the number of printing elements, and the paper feed pitch is This satisfies the condition that the number of printing elements is multiplied by the pitch between adjacent lines, and the number of each line to be printed can be expressed by a formula using the number of printing elements N of the print head and the pitch P of each printing element. It is now possible to do so.

In this embodiment, by first printing in the column direction, each printing element prints the O line, 2nd line, 4th line, 6th line, and 8th line. After that, after feeding the paper for 5 dots, printing is performed in multiple directions, resulting in 5 lines, 7 lines, and 9 lines.
Line, 11-line, and 13-line printing is performed.

By repeating this operation, each line is printed without overlapping each other, and each line is printed in opposite directions. however,
In the case of this embodiment, since dot gaps occur before the 3rd line, the actual printing line is started from the 4th line, and for the lines before that,
It is controlled to perform blank printing in which the printing element is not operated.

Therefore, in this embodiment, since the print head is provided with a plurality of printing elements at a predetermined pitch, a plurality of lines can be printed simultaneously by printing in one direction, and the printing speed can be increased. Moreover, since the printing dots produced by the printing element are different for each line, each dot
The positions of ~ are averaged, and printing unevenness can be reduced. Furthermore, since the paper feed pitch is always constant, paper feed control becomes easy and the paper feed amount can be maintained with high precision.

The relationship between the number of printing elements and the pitch between printing elements in the present invention is such that the number of printing elements is an odd number, the pitch between printing elements is an even multiple of the pitch between adjacent lines that are actually printed, and the paper feed By setting the pitch to be twice the number of printing elements as the pitch between adjacent lines, it is possible to print multiple lines at the same time, and each line is printed in opposite directions. 1) If the even number is a multiple of the number of printing elements, some lines will be scanned multiple times by the printing elements, while others will not be scanned at all and no printing will be done. A line will be generated.

In other words, is the pitch between the printing elements adjacent to each other, the mark of the pitch between the lines? When the number of elements is multiplied by an even number, the integer ∆ of the paper feed pitch becomes equal to the pitch between printing elements, so if paper is fed at this pitch, after several paper feeds, the The printing element will overlap the line being scanned. Since the pitch between printing elements is an even multiple of the pitch between adjacent lines, no printing element is placed on a line adjacent to this overlapping line, and therefore, a line that is scanned multiple times This results in lines that are never scanned. Table 1 shows specific examples of combinations of such relationships, and as described above, the pitch between printing elements in the present invention is an even multiple of the pitch between adjacent lines (however, this The even number is set as a multiple of the number of printing elements (excluding multiples of the number of printing elements).

In addition, FIGS. 2 to 4 each show other embodiments of the present invention. In FIG. 2, five printing elements are formed at a pitch of 4 dots, and the paper feed pitch is set at 5 dots. In Fig. 3, 5 printing elements are formed at a 6-dot pitch and the paper feed pitch is set to 5 dots, and in Fig. 4, 7 printing elements are formed at a 4-dot pitch and the paper feeding pitch is set to 5 dots. It has 7 dots. In any of the above cases,
This satisfies the conditions of the number of printing elements, the pitch between printing elements, and the paper feed pitch.

In the embodiment shown in FIG. 2, by performing the first forward printing, each printing element prints each of the O line, 4th line, 8th line, 12th line, and 16th line. Thereafter, after the paper is fed by 5 dots, printing is performed in the backward direction, thereby printing 5 lines, 9 lines, 13 lines, 17 lines, and 21 lines. In this case, the actual printing line is controlled to start from 12 lines.

In the embodiment shown in FIG. 3, by performing the first forward printing, each printing element prints the O line, 6th line, 12th line, 18th line, and 24th line, and then By feeding the paper for 5 dots and printing in the backward direction, 5 lines and 11
Lines, 17 lines, 23 lines, and 29 lines are printed, and in the case of this embodiment, the actual printing line is controlled to start from the 20th line.

In the embodiment shown in FIG. 4, by performing the first forward printing, each printing element prints each line of 0 line, 4 line, 8 line, 12 line, 16 line, 20 line, and 24 line. After printing, the paper is fed by 7 dots and printing is performed in the backward direction, thereby printing 7 lines, 11 lines, 15 lines, 19 lines, 23 lines, 27 lines, and 31 lines. In this embodiment, control is performed so that the actual printing lines start from 18 lines.

Therefore, in each of the embodiments shown in FIGS. 2 to 4, as in the previous embodiment, a plurality of lines are simultaneously formed, each line does not overlap, and each line runs in opposite directions. The printing speed can be increased, uneven printing can be reduced, and deterioration of printing quality can be prevented.

Further, in any of the embodiments described above, since the paper feed pitch is always constant, paper feed control can be easily performed and the paper feed amount can be maintained with high accuracy.

Furthermore, FIGS. 5 and 6 show an embodiment of an inkjet printer to which the printing method for a serial printer according to the present invention is applied, in which a cylindrical platen 1 is rotationally driven by a motor (not shown). The paper 2 is conveyed by the platen 1 at a predetermined pitch. Further, in front of the platen 1, a carriage shaft 3 is disposed parallel to the platen 1, and a carriage 4 is mounted on the carriage shaft 3 so as to be able to reciprocate along the platen 1. . At the top of the carriage 4, four ink jet heads 5, 5, .

Further, as shown in FIG. 6, the inkjet head 5 has a glass substrate 6, and at the tip of one side of the glass substrate 6, in this embodiment, 11 ink jets are provided. Nozzles 7, 7, . . . are arranged vertically at a pitch of 2 dots. In addition, the above-mentioned base plate 6
are provided with ink passages 9, 9, . . . corresponding to the respective nozzles 7, 7, . Viezo elements 10, 10, . By changing the pulse voltage, the ink ejection rate from the nozzle 7 can be changed and the print clarity can be varied.

Next, the printing operation of this embodiment will be explained with reference to FIG.

In this embodiment, first, the carriage 4 is moved in the forward direction along the carriage IN13, and a pulse voltage is applied to the viezo element 10 of the inkjet head 5 of the desired color, so that ink is ejected from the desired nozzle 7. is ejected, and this ink lands on the paper 2 in the form of dots to perform monochrome or color printing. and,
In this embodiment, by performing the first forward printing, each nozzle 7 prints each line every 2 dots, such as the O line, the 2nd line, and the 4th line, up to 20 lines.

Thereafter, after the paper has been fed by 11 dots, a pulse voltage is applied to each of the vieso elements 10 of the inkjet head 5 while moving the carriage 4 in the backward direction, so that 31 lines such as the 11th line and the 13th line are generated. Printing is now possible.

Therefore, in this embodiment as well, it is possible to increase the printing speed, prevent deterioration of print quality, and furthermore, it is possible to easily control the paper feed and maintain the paper feed amount with high precision. It becomes possible to do so.

Note that the present invention is not limited to the above embodiments,
Various changes can be made as necessary.

〔Effect of the invention〕

As described above, the printing method of the serial printer according to the present invention can print without overlapping each line when bidirectional printing is performed, increasing the printing speed and efficiently printing with high print quality. can be done.

Further, since the paper feed pitch is constant, paper feed control becomes easy, and the paper feed amount can be maintained with high accuracy.

[Brief explanation of drawings]

Figures 1 to 7 show examples of the present invention; Figure 1 is an explanatory diagram showing a printing method when five printing elements are formed at a 2-dot pitch; 4 printing elements
An explanatory diagram showing the printing method when using the dot pitch,
Figure 3 is an explanatory diagram showing a printing method when five printing elements are formed at a 6-dot pitch, and Figure 4 is an explanatory diagram showing a printing method when seven printing elements are formed at a 4-dot pitch. , FIG. 5 is a schematic perspective view showing an inkjet printer for carrying out the printing method of the present invention, and FIG. 6 is a 'i55
7 is an explanatory diagram showing a printing method using the inkjet printer of FIG. 5, and FIGS. 8 and 9 are explanatory diagrams each showing a conventional printing method. DESCRIPTION OF SYMBOLS 1... Platen, 4... Carriage, 5... Inkjet head, 7... Nozzle, 10... Viezo element.

Claims (1)

[Claims] In a printing method for a serial printer that performs bidirectional printing at a predetermined paper feed pitch while reciprocating a print head in which multiple dot printing elements are formed on a print head that can reciprocate along a platen. , the number of printing elements of the print head is an odd number, the pitch between each printing element is an even number that is not a multiple of the number of printing elements of the pitch between adjacent lines actually printed, and the paper feeding pitch is A printing method for a serial printer, characterized in that printing is performed by setting the pitch between adjacent lines to be twice the number of printing elements.