JPS5845897Y2 - impact dot printer - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an impact type dot printer.

Printers that form dot characters by appropriately combining two-dimensional dot matrices are generally called dot printers and are widely put into practical use.

Various types of dot printers have been proposed.

One method is to rotate a helical drum with spiral protrusions on its outer circumferential surface, scan the helical protrusions continuously in the horizontal direction, and hit the protrusions with a hammer through printing paper to sequentially create dots. It is called a spiral bar printer and prints the desired dot characters.

FIG. 1 is a schematic diagram of a conventional spiral bar printer.
Figure a is a perspective view, and figure a is a plan view.

In the figure, reference numeral 1 denotes a helical drum, and on its outer peripheral surface, spiral protrusions 1a with one period per character width are continuously provided for a length corresponding to the number of digits in one line to be printed. .

Note that 1b is a rotation axis. 2 is printing paper, 3 is a blade-like hammer, and the number of hammers equal to the number of digits in one line to be printed is in the printing line direction, and the helical drum 1
are arranged in parallel facing each other.

Note that the length of the striking surface of each hammer 3 is approximately equal to the width of one character.

In this spiral bar printer, by hitting each blade-shaped hammer 3 against the spiral protrusion 1a through the printing paper 2, one dot is created on the printing paper corresponding to the intersection of the tip of the hammer and the spiral protrusion 1a. can be formed.

Each of the above intersection points is shifted to the right by one character width by rotating the helical drum 1 once in the direction of arrow A. Therefore, by sequentially driving each hammer 3 at an appropriate timing, it is possible to print one dot line with one rotation of the helical drum. is possible,
Further, by feeding the printing paper 2 in the direction of arrow B, dots can be printed sequentially in the vertical direction as well.

Therefore, by controlling the rotational drive of the helical drum 1, the paper feeding drive, and the drive timing of the hammer 3, dot characters can be printed on the printing paper 2.

However, in this helical bar printer, the diameter of the helical drum 1 is relatively large and its weight is quite heavy, resulting in a large inertia, which results in poor starting and stopping characteristics and a drawback that high-speed control is difficult. .

Furthermore, since the machining accuracy of the spiral protrusion 1a affects the horizontal dot alignment, there is also the drawback that machining is relatively difficult.

Furthermore, the shape of the dots printed by the filter becomes a parallelogram, and the quality of the characters deteriorates.

FIG. 2 is a perspective view of another conventional example of a dot printer.

In the figure, reference numeral 4 denotes a flat platen that can be shifted in the print line direction, and triangular prism-shaped projection bars 4 a , 4 b , . . . are provided on the surface of the platen at every other digit.

5 is an ink ribbon. In this flat platen type printer, by hitting the hammer 3 against the protruding bars 4a, 4b, etc. via the printing paper 2 and the ink ribbon, the printing paper is You can print one dot on top.

Then, by sequentially shifting the platen 1 to the right by one dot pitch width and driving the hammer 3 according to the character pattern to be printed, one dot line can be printed.

If dot characters are to be formed in a matrix of 7 x 5 dots in the vertical and horizontal directions, one dot line can be printed by shifting the platen 1 to the right by 5 dots and hammering.

After printing one line of dots, move the printing paper upwards by one dot.
The paper is fed by the width of the dot, and thereafter dot characters are printed using the same control.

According to this flat platen type printer, the weight of the platen 1 is light, making it easy to start and stop, and the protruding bar 4
Since there is no need to consider the manufacturing accuracy of a and 4 b, the processing of the platen 1 becomes easier, and since the dots are rectangular, the character quality is good, which eliminates the disadvantages of spiral bar printers. can.

However, in a flat platen type printer, the striking point of the hammer 3 is always the same, so the protruding bar 4 a
, 4b... have the disadvantage that they wear out very quickly, and an ink roller cannot be used, and it can only be applied when an ink ribbon is used.

Therefore, the purpose of the present invention is to eliminate the above-mentioned conventional drawbacks, to provide an impact-type dot printer that can suppress inertia as much as possible, has less wear on protrusions, has good character quality, and is easy to manufacture. purpose.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 3 is a schematic perspective view of an impact type dot printer according to the present invention, and FIG. 4 is an explanatory diagram of the positional relationship between a hammer and a drum of the impact type dot printer according to the present invention.

In the figure, 11 is a drum rotation shaft, 12 a , 12 b ,
12 C... are drums, each of which is fixed to the drum rotating shaft 11 at an interval of one digit pitch in the rotational direction and slidably attached in the axial direction.

Moreover, on its outer peripheral surface, a single circular protrusion 13a,
13 b , 13 C . . . are provided.

14 is a drum holder, and 15 is a drum shift shaft.

A screw is cut into the drum shift shaft 15, and the drum holder 14 is screwed to the drum shift shaft 15.

Therefore, if the drum shift shaft 15 is rotated clockwise, the drum holder 14 will be shifted to the right, and conversely, if the drum shift shaft 15 is rotated counterclockwise, the drum holder 14 will be shifted to the left.

If the drum holder 14 shifts, each drum 12a,
12b... are also pushed by the drum holder 14 and shifted.

16 a , 16 b , 16 C . . . are blade-shaped hammers, and each drum 12 a , 12 b .
・They are arranged horizontally in parallel, facing each other.

Reference numeral 17 is a printing paper, and 18 is an ink roller, which applies ink to the protrusions 13a, 13b, . . . of each drum.

Next, the operation of the impact type dot printer according to the present invention will be explained.

It is assumed that each dot character is formed by appropriately combining 7 x 5 dots in the vertical and horizontal directions.

At the initial stage, each drum 12a, 12b, . . . is set at the leftmost position (referred to as home position).

Next, each hammer 16 is
Solenoids (not shown) provided corresponding to a, 16b, . . . are energized and hammered.

As a result, the tip of the hammer and the protrusion 13a are driven.

The dots of the first dot row and the first column are printed on the printing paper 17 corresponding to the intersections of the dots 13b, . . . .

On the other hand, since the drum rotation shaft 11 and the drum shift shaft 15 always rotate at a predetermined speed, each drum 12 a , 12 b . . . after the first column of dots is printed.
... shifts one dot pitch to the right.

At this time, if the hammers 16a, 16b, . 4th. Once the dots in the fifth column are printed, printing of all the characters to be printed in the first line in the first dot line is completed.

Note that the impact points of the protrusions 13a, 13b, . . . change sequentially because the drums 12a, 12b, . . . rotate.

Thereafter, a mechanism (not shown) advances the printing paper 17 by one dot pitch in the direction of arrow C, and rotates the drum shift shaft 15 counterclockwise at high speed to move each drum 12 a.
, 12b... are returned to their home positions, and thereafter, the shift, rotation, and hammer drive of the drum are controlled in the same way as for the first dot row. Then, the printing of the second dot row is completed, and the drum is started again. Return to the home position, feed the paper, and then print up to the 7th dot line in the same way.
All dot characters of the desired first line are printed.

In the above description, the drum rotating shaft 11 and the drum shift shaft 15 are continuously rotated, but they may be rotated intermittently, such as rotating every time one dot is printed.

FIG. 5 is a cross-sectional view of the drum 12 according to the present invention. FIG. This is an example in which it is formed on the gold surface of the outer peripheral side of No. 12.

FIG. 6 is a perspective view of another embodiment of the impact type dot printer according to the present invention.

Note that the drum shift mechanism is omitted.

In the figure, 21 is a drum rotating shaft, 22 a, 22 b...
. . . are drums, each of which is attached to the rotating shaft 21 at a three-digit pitch, locked in the rotational direction and slidable in the axial direction.

Furthermore, a single spiral protrusion 23 a is provided on the outer peripheral surface of each drum.
, 23b... are provided.

Incidentally, these spiral projections 23a, 23b...
The length of the axial component is approximately one character width.

24a, 24b, . . . are blade-shaped hammers, the horizontal length of the striking surface of which is approximately three orders of magnitude, and a large number of hammers are arranged in the horizontal direction.

In this printer, each blade-shaped hammer 24
a, 24b... by hitting the helical protrusions 23a, 23b... through printing paper (not shown), so that the tips of the hammers and the helical protrusions 23
One dot can be formed on the printing paper corresponding to the intersection of a, 23b, . . . .

The above-mentioned intersection points are the drums 22 a , 22 b . . .
Each rotation of the hammer 24a shifts the width of one character to the right.

Drums 22a and 24b are sequentially driven at appropriate timings depending on the character pattern to be printed.
, 22b... 3n-2 in one rotation (however, n=
1.2...) The first dot line of the dot character in the digit can be printed.

Thereafter, each of the drums 22 a , 22 b , . However, n = 1.2...
・) The first dot row of the digit can be printed.

And finally, the drums 22a, 22b...
... is shifted one digit to the right, and 3n (however, n
=1.2...) When the first dot line of the digit is printed, printing of the first dot line of all dot characters to be printed on the first line is completed.

Thereafter, by feeding the printing paper by one dot pitch, returning each drum 22a, 22b, etc. to its home position, and performing the same control as above, the second dot row, third dot row, etc. ...The seventh dot line is printed, and printing of all dot characters for one line is completed.

Note that the mechanism for shifting the drum in the digit direction is not limited to the above-described embodiment; for example, the drum holder 14 may be shifted by an end cam that rotates in synchronization with the drum rotation shaft 11.

As described above, according to the present invention, instead of the conventional helical drum having a length of one line, a plurality of small and lightweight drums with a one-dot pitch length or a one-digit pitch length are provided, and each drum is shifted to perform printing. This allows the total weight of all drums to be significantly reduced.

As a result, inertia can be suppressed as much as possible, and the starting and stopping characteristics of the drum can be improved, and high-speed printing can be easily controlled.

Also, according to the present invention, since the hammer impact point on the protrusion changes,
The wear of the protrusions becomes uniform throughout, and there is no need to replace one part due to excessive wear.

Furthermore, when a single circular protrusion is implanted on the outer peripheral surface of the drum, each printed dot has a rectangular shape, making it easier to see and improving the character quality.

Further, when the protrusions are circular, the drum shape becomes simple and its processing becomes easy.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional spiral bar printer.
FIG. 2 is a perspective view of another conventional example of a dot printer, FIG. 3 is a schematic perspective view of an impact type dot printer according to the present invention, and FIG. 4 is a perspective view of the present invention. FIG. 5 is a cross-sectional view of the drum, and FIG. 6 is a cross-sectional view of a case where projections are formed on the entire outer peripheral side surface of the drum, and FIG. 6 is a perspective view of another embodiment of the impact type dot printer according to the present invention.

Claims (3)

[Scope of utility model registration request] (1) In an impact type dot printer that has a rotatable drum having protrusions on its outer peripheral surface and a hammer that hits printing paper against the protrusions to print dots on the printing paper, a plurality of drums are provided and each drum is used for printing. An impact type dot printer characterized in that it is provided with means for shifting in the row direction, and a hammer is driven in accordance with the rotation and shift of a drum to form dots on printing paper. (2) The impact type dot printer according to claim 1, which is a registered utility model, characterized in that one drum is provided for at least one digit, and the protrusion has a single circular shape. (3) The impact type dot printer according to claim 1, which is a registered utility model, characterized in that one drum is provided for each of a plurality of digits, and the protrusion has a single spiral shape.