JPS61230957A - Printing hammer of dot printer - Google Patents

Abstract

PURPOSE:To perfectly eliminate the unevenness of the envelope of the longitudinal line and transverse line constituting a character or reduce the same as small as possible and the visual offensive sight due to the unevenness especially generated in an oblique line, by forming the impact surface of a printing hammer into a rectangle or oval long in the horizontal direction of a character at a time when a character is constituted of a dot. CONSTITUTION:When a current is supplied to the coil 11a of an electromagnetic mechanism 11, the magnetic flux of a permanent magnet 9 is negated by the inverse exciting magnetic flux of the coil 11a and an armature 12 is released from the electromagnetic mechanism 11. By this operation, an impact arm 14 is driven by the spring elasticity stored in a leaf spring 15 and a dot is printed by a printing hammer 17. The impact surface 17a of this printing hammer 17 is formed into a rectangle or oval long in a transverse axis (X-axis). By this method, the curve drawn by a one-dot broken line 8 of a drawing showing a printed character being the one tracing the envelope of the character when dot printing was performed and can appear smoothly.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a printing hammer for a dot printer.

In particular, this relates to a type of printing hammer that, unlike the wire tod type, has a small protrusion-like printing hammer at the tip of the impact arm, and directly hits the printing hammer to print dots to form characters. .

Conventional technology Currently, the wire tod type print head is widely used as the print head for impact type dot printers.The basic structure of this type of print head is described in Japanese Patent Application Laid-Open No. 56-49278, etc. As seen in many prior art, it is as shown in FIG. Here,
Reference numeral 101 designates a leaf spring/impact arm, and an armature portion 102 is provided at an intermediate position in the longitudinal direction, and a wire 1 used as a printing hammer is attached to the tip end of the armature portion 102.
One end of 03 is fixed. The leaf spring/impact arm 101 is fixed with its tip toward the center and its periphery to the housing 104, and a plurality of them (corresponding to the maximum number of dots) are independently arranged radially. Reference numeral 105 denotes an electromagnetic mechanism, which is independently disposed at a position facing each armature section 102. On the other hand, each wire 103
is a guide plate 107 provided on the guide head 106
and 108, it is smoothly guided to the printing location.

Since the wire tod type print head has such a structure, the wire 103 which is the printing/marker
is a very thin steel wire, and its cross-sectional shape must be circular. This is because if it were made into a shape other than circular, stress concentration would easily occur in the wire 103 when printing is struck by the end face. If the wire is repeatedly hit hundreds of millions of times, it will break due to fatigue, and when guiding the wire 103 through the guide plates 107 and 108, a hole corresponding to the cross-sectional shape must be drilled in the guide plate. This is because, of course, the wire 103 is extremely thin, making it difficult to manufacture the guide plate.

Problem to be Solved by the Invention However, when a character is formed by printing dots with a hammer having a circular cross-sectional shape, the envelope lines of the horizontal and vertical lines forming the character are not comparable. However, the envelope made up of dots on the slanted line becomes extremely uneven.
It has been pointed out that this not only makes the letters themselves difficult to read, but also harms their aesthetics. This is a well-known phenomenon in which diagonally extending lines appear jagged when characters are printed using a wire tod printer.

Figures 16 to 18 show greatly enlarged diagrams of the envelope portion when these inclined lines, etc. are composed of dots. In each figure, the straight lines 110, 111 and 1
12 indicates that the flow of the enveloping line of the lines constituting the character should originally be such a line, and the circle 113 drawn with a thick solid line indicates the range to be struck by the wire mark, and the circle 113 is drawn with a thin solid line. A circle 114 with a lift force of 1
A circle 114 is formed concentrically around 13. In addition, in each figure, a circle 113 is placed at a position offset from the two-dot chain line.
．． The reason why there is a center of 114 is because dot printers display characters in a dot matrix.
This is because when drawing a diagonal line, the point on the matrix closest to the diagonal line is selected and drawn. A curve t drawn by a dashed line 115 in each figure
± This traces the envelope line of the characters when printed with dots. In FIG. 16, the area indicated by 116 has a smoothness close to that of the envelope line indicated by a dashed line 115 because dots are continuously placed in the horizontal direction. However, l17.118, 119.121.1
The section indicated by 22 and the sections indicated by 120 and 123 have unevenness, particularly in the latter curved section. Each figure is a considerably enlarged diagram, but even when characters of about 10 or 12 points are actually printed using a 24-dot matrix, the diagonal lines or curved parts in the envelope line of the characters are visually equivalent. It becomes awkward and an eyesore. Therefore, in a dot printer, it is usually impossible to ideally draw the hatched portions of characters. If you try to make the shaded area closer to the ideal, it will have to be displayed using a larger number of dot matrices, which is a contradictory technical problem in that the configuration and manufacturing of the print head will be extremely difficult. occurs. This invention was created with the aim of solving the above-mentioned problems by devising the shape of the striking surface of the printing hammer.

Means for Solving the Problems This invention does not use a wire tod type print head, but instead uses a plurality of impact arms arranged centrially, and a small protrusion at or near the center tip of each impact arm. It is applied to a print head of a dot printer in which each of the small protrusions is used as a printing hammer, and its feature lies in the shape of the striking surface of the printing hammer.

This will be explained below using FIGS. 1 to 5.

1 and 2 are enlarged views of the tip of the impact arm of the print head of a dot printer in which the hammer of the present invention is utilized. Reference numeral 1 denotes an impact arm, and a small protrusion-like printing hammer 2 is provided at or near the tip of the impact arm. In the print head, such impact arms are provided centrially in a plurality of independent side numbers corresponding to the number of dot matrices. In the non-printing state, each of the impact arms 1 arranged in this manner is located at a position away from the printing paper 4 mounted on the platen 3 and the ink ribbon 5 provided almost in close contact with the printing paper 4, as shown in FIG. , and is waiting for a signal to be input to a drive mechanism (not shown).

When a signal is instantaneously input to the drive mechanism, the impact arm l springs up in the direction of the platen 3, as shown in FIG. The dots are printed on the printing paper 4, and then the state shown in FIG. 1 is restored. Each impact arm 1 in the print head performs such operations continuously or intermittently to print characters in the form of dots. The key point of this invention is that the planar shape of the striking surface 2a at the tip of the printing mark 2 is
As shown in Figures to Figure 5, when characters are composed of dots, the characters are made into horizontally long rectangles (Figure 3), ellipses (Figure 4), or elliptical diameters (Figure 5). be,
In these figures, the direction of the arrow of the two-dot chain line indicates the horizontal direction of the characters when the characters are composed of dots and printed, and each printing hammer 2 is arranged on the impact arm with such a relationship. Must be set.

6 to 8 are enlarged views of the case where a dot is formed using the print head 2 having such a striking surface shape and an inclined line similar to that shown in FIGS. 16 to 18 is drawn. and FIGS. 9 to 11.

In each figure, a thick solid line 6 indicates the range hit by the printing hammer 2, a thin solid line 7 indicates the dots printed on the printing paper via the ink ribbon, and a one-dot m line 8
The curve drawn in is the one that traces the enveloping line of the characters when printed with dots.

In this case as well, since matrix display is of course performed, the center of each printing hammer is often not located on the diagonal line shown by the two-dot chain line.

First, if we pay attention to the envelope line, that is, the dotted chain ma shown in FIGS. 6 to 8, which are formed by forming diagonal lines with the printing hammer 2 whose striking surface is rectangular, we can see that when the dots are continuous in the horizontal direction, The envelope is a perfectly straight line (which means
The same is true when the dots are continuous in the vertical direction),
The shaded area has a step-like shape. This step-like part is the first
61gJ to Figure 18, the unevenness may not seem to be much different at first glance, but if you look at it from a visual angle as a diagonal line in characters normally printed by a word processor, etc., you can see that Figures 16 to 18. It will look much smoother than in the case of . This is because a person's visual angle tends to recognize objects that are regularly arranged in the horizontal direction as more stable objects. Therefore, characters formed by printing dots with a printing hammer having a rectangular striking surface are less visually obtrusive, easier to read, and more aesthetically pleasing.

Next, if we pay attention to the enveloping line, that is, the dashed-dotted line 8 in FIGS. 9 to 11, in which diagonal lines are formed by the printing hammer 2 whose striking surface is oval or elliptical, in this case, the horizontal direction When the dots are continuous, the envelope will not be a perfect straight line, but it will be much straighter than in Figures 16 to 18, and from a visual perspective it will be easier to see if the hitting surface is rectangular. It looks like there is almost no difference. On the other hand, the vertical enclosing line is similar to the section indicated by 116 in FIG. 16, but as described above, the unevenness of this section is hardly noticeable from a visual angle. The most effective point of this oval or elliptical printing hammer 2 is that the shaded area is much smoother than when using the rectangular striking surface shown in FIGS. 6 to 8.

Embodiment Next, an embodiment of the present invention will be described with reference to FIGS. 12 to 14. The printing head in which the printing hammer of the present invention is used is shown in FIG. 12. In the figure, 9 is an annular permanent magnet, lO is a main yoke consisting of a tubular part 10a and a flange part 10b, and 11 is an independent ring around the main yoke. 12 is an armature that is independently arranged facing each electromagnet mechanism, 13 is an annular auxiliary yoke formed in a comb shape toward the periphery, and surrounds each armature 12. I'm here. The circuit composed of these parts is a permanent magnet 9
This constitutes a magnetic path. And armature 1
2 is provided with an impact arm 14 extending toward the center, and both are supported by a leaf spring 15 with a fixed end at the peripheral edge thereof to form an impact portion 16. A small protrusion-shaped printing hammer 17 is disposed at or near the tip of each impact arm 14 of this impact portion 16, and a plan view of the impact portion 16 is shown in FIG.
Further, as shown in FIG. 14, which is an enlarged perspective view of the disposed area of the printing hammer 17 at the tip of the impact arm 14, each impact portion 16 is separated by a centripetal slit 18.

In FIG. 12, the impact portion drawn on the right side is in a non-printing state, and the armature 12 is attracted to the electromagnetic mechanism 11 by the magnetic flux of the permanent magnet 9 generated in the magnetic path, and is waiting for energization. are doing. When the coil lla of the electromagnet mechanism is energized, the magnetic flux of the permanent magnet 9 is canceled by the reverse excitation flux of the energized coil lla, as shown on the left side of FIG. It is released from the mechanism 11, and thereby the impact arm 14 is driven by the spring elasticity stored in the leaf spring 15, and the printing hammer 17 prints a dot. As shown in FIGS. 13 and 14, this printing hammer 17 is connected to the horizontal axis (X
They are arranged with a positional relationship such that a predetermined pitch τ in the direction of the axis (axis) and a predetermined pitch σ in the direction of the vertical axis (Y vehicle). Note that the horizontal axis (X-axis) direction corresponds to the driving direction when printing characters with the print head.

Here, the striking surface 17a of the printing hammer 17 is the horizontal axis (X axis)
It is formed into a long rectangle, oval or oval shape. To form the printing hammer 17 with such a shape,
It is also possible to leave only the printing hammer 17 by cutting the tip of the impact arm 14, but since this requires very fine processing conditions, it is more appropriate to use die carving using electrical discharge machining. It can be said that it is a processing method.

The relationship between the shape of the striking surface of the printing hammer 17 and the characters formed by printing dots with the printing hammer 17 is as explained using FIGS. 6 to 11 [ff] above. Even in the case of forming a rectangular, oval, or elliptical shape, there are various options for selecting the ratio of the lengths in the vertical direction and the horizontal direction. It is generally said that the characters printed in newspapers are the easiest for ordinary people to read, but it is known that the ratio of the vertical line thickness to the horizontal thickness of the lines that make up the characters is 4:1. ing. Therefore, in this case, if the ratio of the long side to the short side is set to 4:l for the rectangular hitting surface, and the ratio of the long axis to the short axis for the oval hitting surface is set to 4:l, then the newspaper will be printed. This is extremely convenient for composing characters similar to the characters shown.

Effects of the Invention The hammer of the dot printer of this invention has small protrusions formed on the impact arm and is used as a printing hammer to print dots to form characters. Should the unevenness of the route be completely eliminated?
Alternatively, it has the effect of making it as small as possible, and in particular, preventing unevenness that occurs in diagonal lines from becoming visually unsightly. As a result, when printing characters with a dot printer,
It is possible to compose characters that are easy to read and have a rich aesthetic appeal.

[Brief explanation of drawings]

Figures 1 and 2 are enlarged views of the tip of the impact arm, Figures 3 to 5 are diagrams showing the shape of the striking surface of the printing hammer, Figures 6 to 11 are slanted lines of characters, etc. A greatly enlarged diagram of the envelope when composed of dots, 1st
Figure 2 is a sectional view of the print head, Figure 13 is a plan view of the impact part, Figure 14 is an enlarged perspective view of the print hammer installation area, and Figure 15 is a basic diagram of the prior art wire tod type print head. The diagrams illustrating the structure, FIGS. 16 to 18, are greatly enlarged views of the envelope portion when slanted lines and the like are constructed of dots. In each figure, l is the impact arm, 2 is the printing hammer, 2a is the striking surface of the printing hammer, 3 is the platen, 4 is the printing paper, 5 is the ink ribbon, and 6 is the large solid line, which is the area hit by the printing hammer 2. , 7 is a thin solid line and indicates the range of dots printed on the printing paper via the ink ribbon, and 8 is a curve that traces the envelope of the character when the dots are printed. Agent Patent Attorney Toshikazu Nagai Figure 2 Figure 3 Figure 4 Figure 5 Figure 8 Figure 11 Figure 12 Figure 18

Claims (3)

[Claims] (1) A printing hammer for a dot printer in which a plurality of impact arms are arranged centrially, a small protrusion is arranged at or near the center end of each impact arm, and each small protrusion is used as a hammer, A printing hammer for a dot printer, characterized in that the striking surface of the printing hammer is formed into a rectangular, oval or oval shape which is elongated in the horizontal direction of a character when the character is composed of dots. (2) The printing hammer for a dot printer according to claim (1), wherein the shape of the striking surface of the printing hammer is a rectangle with a long side to short side ratio of 4:1. (3) The printing hammer for a dot printer according to claim (1), wherein the striking surface of the printing hammer has an elliptical shape with a ratio of major axis to minor axis of 4:1.