JPS62164541A - Dot printer head - Google Patents

Abstract

PURPOSE:To enhance line quality of slant lines and print with a favorable finish, by providing a function of printing a print dot train at either of two positions which are shifted from each other by a half-pitch amount in a main scanning direction. CONSTITUTION:A function of mechanically shifting a train of dots 4 by a half pitch P/2 in a main scanning direction X is provided. Dots 4' indicated by one- dash liens represent the dot positions after a half-pitch shift. The shift of dots means a shift of the positions of the dots relative to a paper on which the dots are to be printed. The shift may be performed by a mechanism in which the dot train itself is mechanically moved in the direction X, or may be performed by a mechanism wherein the paper is moved in the direction X. An actual printing operation is conducted while feeding the paper or a head itself in a direction Y. By effecting the half-pitch shift in the direction X each time a one-pitch feed in the direction Y is conducted and repeating this operation, a smooth slant line can be printed. Accordingly, the line quality of the slant line can be enhanced, and printing with a favorable finish can be performed.

Description

[Detailed description of the invention] (Technical field of invention) The present invention is applied to a dot printer head.

[Prior art and its problems]

Dot printers are widely used as printers for printing various characters and graphic patterns. These dot printers print dots using dots arranged in a matrix, and as a collection of these printed dots, characters,
Because it is a method of expressing graphic patterns, it is characterized by the ability to print with great flexibility. These dot printers can be roughly divided into dot impact type and thermal type.In the former, the impact hammer that constitutes the driver 1- is mainly used with a circular impact surface, while in the latter, the heating element that constitutes the dot is Those with a rectangular surface are the mainstream. Among these, printers with circular dots can print vertical lines, horizontal lines, and diagonal lines with almost the same line quality, but printers with square dots have the problem that these line qualities differ. .

For example, FIG. 2 shows a portion of a head used in a conventional thermal printer. Here, dot 1 consisting of a heating element is
Electrode layers 2 and 3 are connected to each dot 1 arranged in a row in the X direction in the figure. A voltage is applied between the electrode layers 2 and 3, and the heating element forming the dot 1 generates heat.

In the present application, for convenience of explanation, the dots 1 to 1 are illustrated in a state where they are not completely in close contact with each other, but in reality, there is a gap between each dot. In addition, in the figure, the direction X is the main scanning direction of the printer (for example, the direction in which dots are arranged in a line printer),
Direction Y indicates the sub-scanning direction of the printer (for example, the paper feeding direction in a line printer).

Let us now consider the case where printing is performed using a head in which square dots are arranged in the main scanning direction X, as shown in FIG. As a result of printing, as shown in Figure 4(a), smooth line quality is obtained for vertical and horizontal lines, but as shown in Figure 4(b), there are steps in diagonal lines, resulting in smooth lines. quality is no longer available. FIG. 3 shows an example of printing specific characters using such a head. The vertical and horizontal lines that make up the characters are smooth, but the diagonal lines have noticeable steps, giving the overall impression of the characters.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a head for a dot printer that can improve the line quality of diagonal lines and print with a good finish.

[Summary of the invention]

A feature of the present invention is that, in a dot printer head, a plurality of printing dots are arranged in a row in the main scanning direction, and the printing dot rows are shifted from each other by a half pitch of the printing dots along the main scanning direction. The present invention has a function of printing on printing paper at two relative positions, improves the line quality of diagonal lines, and makes it possible to print with a good finish.

(Embodiments of the Invention) The present invention will be described below based on illustrated embodiments. FIG. 1(a) shows a part of a head according to an embodiment of the present invention. The dots 4 have a square shape and are arranged in a row so that their sides are parallel to the main scanning direction X. Each dot 4 has an electrode layer 5J.
5 and 6 (broken line) are connected, and the heating element generates heat due to the voltage applied between both electrodes.

The feature of this head is that the rows of dots 4 are mechanically moved by a half pitch P/2 in the X direction. Figure 1 (
The dot 4' shown by the dashed line in a) shows the position after this half-pitch movement (the electrode layers 5 and 6 are also moved together, but they are not shown). Here, the movement of the dots only requires movement of their position relative to the paper to be printed, and a mechanism for mechanically moving the dot row itself in the X direction may be used, or conversely, A mechanism that moves in the direction may be adopted. The actual printing operation is
This is done while feeding the paper or the head itself in the Y direction in the figure. If the paper is moved half a pitch in the X direction every time it is moved one pitch in the Y direction, smooth diagonal lines can be printed. FIG. 5(a) shows the result of printing diagonal lines using this head. Here, dot row 01
゜[)3. [)5. D7 is shown in Figure 1 (a) (')
'IF Pi This is the dot printed at the position of printing dot 4, and is the dot of dot row D2. D4. D6. D8 is a dot printed at the position of printing dot 4' indicated by the dashed line in FIG. 1(a). If you compare the printing results in FIG. 5 <a,> with the printing results by the conventional head shown in FIG. 4(b), you will see that the diagonal lines are printed more smoothly.

FIG. 1) shows a portion of a head according to another embodiment of the invention. The dots 7 (solid line portions) made up of heating elements are square, similar to the previous embodiment, but are arranged in rows with diagonal lines parallel to the main scanning direction. Note that the electrode layer is omitted in this figure. This head also has a row of drivers l to 7 at a half pitch P/2 in the X direction.
It has a mechanically movable structure. A dot 7' indicated by a dashed line in the figure indicates the position after this movement. When diagonal lines are printed using this head, smoother diagonal lines can be obtained as shown in FIG. 5(b). Note that when printing vertical lines and horizontal lines using this head, the line quality is worse than diagonal lines, but when looking at the print results with the naked eye, based on ergonomic and psychological factors, vertical lines and Since diagonal lines are more noticeable than horizontal lines, the overall quality of printing is improved.

FIG. 1(C) shows a portion of a head according to another embodiment of the present invention. The half-dots 8 consisting of heating elements have a rectangular shape, are arranged along the main scanning direction
A voltage is applied from layer 9.10. A printed dot is formed by combining two of these half dots 8. For example, half dot 8
If a printing dot is formed by a combination of 1, 82.83, 84.85, 86.87, and 88, it will be equivalent to dot 4 in Figure 1(a), and half dots 82, 83.84, and 85°8.
If a printing dot is formed by a combination of 6 and 87, it will be equivalent to dot 4' in FIG. 1(a). It will be seen that if the voltages applied to the electrodes 9 and 10 are controlled to select one of the two combinations described above, the same function as the head shown in FIG. 1(a) can be achieved.

FIG. 1(d) shows a portion of a head according to yet another embodiment of the invention. In this head, instead of mechanically moving the dot rows by half a pitch, two dot rows are arranged with a half pitch offset from each other.

An electrode layer 12 is connected to the dots 11 in the first row, an electrode layer 14 is connected to the dots 13 in the second row as first electrodes, and an electrode layer 15 is connected as a second electrode common to both dots 11 and 13. connected as. If such a configuration is adopted, the same function as the head shown in FIG. 1(a) can be achieved without mechanically moving parts.

Figure 1(e) shows the head shown in Figure 1(d), with each dot arranged in a row so that its diagonal line is parallel to the main scanning direction X, and there are no mechanically moving parts. It can perform the same function as the head shown in FIG. 1 (1)).

Although the present invention has been described above with reference to several embodiments, the present invention is not limited to the above-mentioned embodiments. Any mechanism may be used as long as it has the function of printing in two positions such as the one shown in FIG. Further, the present invention is not limited to thermal head printers, but can be applied to any printer, such as a dot impact type printer, in which the head is formed by an array of dots.

〔Effect of the invention〕

As described above, according to the present invention, the dot printer head is provided with a function that allows printing at the 2 and dot positions where the print dot rows are shifted from each other by half a bit along the main scanning direction. improve quality,
It becomes possible to print with a good finish.

[Brief explanation of drawings]

1(a) to 1(e) are diagrams showing an embodiment of the head according to the present invention, FIG. 2 is a diagram showing an example of a conventional head, and FIG. 3 is a diagram showing an example of a conventional head.
The figure shows type printed with a conventional head, Figure 4 (a), (1)) shows the line quality of a line printed with a conventional head, Figure 5 (a), (t)) FIG. 3 is a diagram showing the line quality of lines printed by the head according to the present invention. 1... Conventional dot, 2.3... Electrode layer, 4.4'
...Dot according to the present invention, 5.6...ff1t'i
i! , 7°7'... Dot according to the present invention, 8.81
~88... Half dot according to the present invention, 9, 10... Electrode layer, 11°13, '1.6.18... Dot according to the present invention, 12°14.15, 17.19. 20... Electrode layer, X... Main scanning direction, Y... a1 scanning direction. Applicant's agent Mr. Sato - Patent application Patent application Utility model registration application Figure 3

Claims (1)

[Claims] 1. Two types of relative arrangement in which a plurality of printing dot rows are arranged in the main scanning direction, and the printing dot rows are shifted from each other by a half pitch of the printing dots along the main scanning direction. A dot printer head characterized by having a function of printing on printing paper at a position. 2. The head for a dot printer according to claim 1, further comprising a mechanism for mechanically shifting the relative positional relationship between the print dot row and the print paper by a half pitch. 3. Claim 2, characterized by having a mechanism for mechanically moving the printed dot row itself by half a pitch.
Dot printer head described in section. 4. The head for a dot printer according to claim 2, further comprising a mechanism for mechanically moving the printing paper by half a pitch. 5. The printing dot row is composed of a half-dot row having a width half that of one printing dot, and is characterized by having a mechanism for combining two predetermined half-dots from this half-dot row to form one printing dot. A dot printer head according to claim 1. 6. It has two rows of printing dots arranged in the main scanning direction,
2. The dot printer head according to claim 1, wherein the second row of printed dots is arranged with a half pitch offset from the first row of printed dots. 7. The dot printer according to any one of claims 1 to 6, wherein each printed dot has a rhombic shape with diagonal lines arranged parallel to the main scanning direction. Head for.