JP2882159B2 - Dot line printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reciprocates a hammer bank holding a plurality of spring-charged dot printing hammers provided side by side along the row direction along the row direction. (L is an integer of 3 or more) The present invention relates to a dot line printer that prints dot rows.

[0002]

2. Description of the Related Art A plate-spring-like printing hammer is held at a non-printing position by, for example, a magnetic attraction force of a permanent magnet, and a release current having a predetermined pulse width is supplied to a release electromagnetic coil (hereinafter simply referred to as an electromagnetic coil). It is well known that a spring-charge type printing hammer that prints by releasing a printing hammer has the following problems.

For example, as disclosed in Japanese Patent Publication No. 55-10385, it is difficult to drive the printing hammers of adjacent digits at the same time. To drive them simultaneously, the pulse width of the current supplied to the electromagnetic coil must be increased. Or increase the peak value. In order to prohibit the simultaneous driving, in this patent, the characters on the type drum are shifted along the circumferential direction so as to prevent the simultaneous driving.

The dot line printer according to the present invention is disclosed in Japanese Patent Application Laid-Open No. 58-11177 and Japanese Patent Publication No. 62-2.
As disclosed in Japanese Patent No. 8755, the dot print hammers are divided into two groups, and each print hammer of the second group is shifted from the standard set position by half the reciprocal of the print density (hereinafter, referred to as a half dot) to provide adjacent print hammers. At the same time.

[0005]

By shifting by half dots in this manner, the number of simultaneously driven printing hammers is reduced, so that power consumption is reduced and the peak value of the coil current flowing through the electromagnetic coil is reduced. This has the effect that the power supply can be made smaller.

However, when the printing speed of a dot line printer becomes extremely high, the number of printing hammers increases, for example, to less than 300. Even if the printing hammers are divided into two groups, the number of printing hammers driven simultaneously increases, and the number of printing hammers increases. And mechanical effects could not be avoided. Further, when the pitch between the printing hammers is reduced, a new problem of magnetic interference occurs.

That is, since the number of printing hammers driven at the same time increases, the flowing current also increases, and a large power supply capacity is required. Further, in the worst case where the mechanical impact becomes large, the distance between the printing hammer hitting portion and the paper changes, and there is a problem that the printing quality is deteriorated.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art and prevent a decrease in print quality due to simultaneous multiple driving.

[0009]

According to a first aspect of the present invention for solving the above-mentioned problems, a plurality of L (L is an integer of 3 or more) dot rows are simultaneously printed at a predetermined pitch along a print row. A plurality of dot print hammers arranged so as to be shifted in the paper feed direction, magnet means for generating a magnetic attraction force to hold the print hammers at a non-printing position, and A release electromagnetic coil provided to correspond to the print hammer and supplied with a pulse current of a predetermined width to cancel the magnetic field of the magnet means, and a hammer bank that holds the print hammer and reciprocates along the row direction. A dot line printer for printing by driving each of said printing hammers in the course of reciprocating movement of said hammer bank, wherein said printing hammers are divided into a plurality of groups of N (N is an integer of 3 or more). In addition to a module configuration in which the number of print hammers equal to the integral multiple of the least common multiple of L and N are integrally formed, and each print hammer in the group does not collide with the paper at the same timing, The print hammer driven second to nth in each group is the same as the other print hammer.
(N) with respect to the standard mounting position when
-1) / (ND).

The second structure of the present invention is arranged at a predetermined pitch along a printing line, and is shifted in the paper feed direction so that L (L is an integer of 3 or more) dot lines can be printed at the same time. A plurality of dot print hammers, magnet means for generating a magnetic attraction force to hold the print hammers at the non-printing positions, and a plurality of magnets for driving the print hammers. A release current coil supplied with a pulse current having a width to cancel the magnetic field of the magnet means; and a hammer bank holding the print hammer and reciprocating in the row direction. A dot line printer that drives each of the printing hammers to perform printing, wherein the printing hammers are N (N is 5 or less).
Divided into the above integers) groups,
In order to prevent the print hammers in the group from colliding with the sheet at the same timing, the print hammers driven second to nth in the group are designated by the marks.
When the character hammers are arranged at equal intervals with other hammers
Driving adjacent print hammers in the group by displacing them by (n-1) / (ND) from the standard mounting position
That is, the start timing pitch is defined by the following equation .

[0011]

(Equation 1)

[0012]

According to the above arrangement, the number of simultaneously driven print hammers is reduced to 1 / N, so that electrical and mechanical influences are reduced.

Further, by forming the print hammer into a module-structured print hammer assembly in which a number equal to the least common multiple of the numerical values L and N or an integral multiple thereof is integrally formed, only one type of print hammer assembly is required. And parts management becomes easy.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 2 is a perspective view showing one example of a spring-charge type dot printing hammer, and FIG. 3 is a side sectional view thereof.

A print pin 2 is mounted on a free end of a leaf spring 1 constituting a print hammer, and a front end of the leaf yoke 2 is attached to a fixed end of the leaf spring 2 via a screw (not shown). 4. The yoke base 5 is fixed to the rear surface. A permanent magnet 6 and a comb yoke 7 are fixed to the yoke base 5, and the front yoke 4, the leaf spring 1, the yoke base 5, the permanent magnet 6, and the comb yoke 7 constitute a magnetic circuit. The leaf spring 2 is attracted to and held by the pole portion of the comb yoke 7 by the above-described permanent magnet 6, and when the release coil 8 is excited, it flies by the bending energy of the leaf spring 1 and the printing pin 2 causes the paper (not shown). Print on top.

In the following embodiment, the printing density is set to 180 DPI (180 inch / inch) for the sake of simplicity.
Dot), and the number L of dot lines to be printed simultaneously is 6.

FIG. 1 shows the arrangement of the printing hammers of this embodiment. Nine printing hammers are grouped into one group (9 shifts), and 18 of these two groups, that is, 18 of which is the least common multiple of 6 and 9 are shown. 1 shows a print hammer assembly 10 having a module configuration with one leaf spring having a print hammer connected below. Each of the printing hammers 21 to 29 in the assembly 10 is branched from an intermediate portion, and a printing pin is mounted on the upper end thereof through means such as welding or caulking. Numerical values 21 to 29 of the printing hammers indicate the order of driving in each group. The printing hammers are arranged so as to be able to simultaneously print 6 dot lines by being shifted by one dot line in the paper feed direction. Line direction to avoid collision,
That is, they are shifted by a predetermined amount in a direction perpendicular to the paper feeding direction.

As is well known, the assembly 10 is housed and held in a hammerbank (not shown) which is reciprocated in the row direction by a shuttle mechanism comprising a rotary motor and a cam or a linear motor. Now, printing hammer
Is the distance of 1 / D (D: number of print dots per unit length)
Assuming that the moving time is T (ms) and the shuttle speed of the hammer bank is v (= (1/180) / T inch / ms), the drive start timing pitch of each print hammer is t = T
/ 9, and the distance x that the hammer bank moves from when one print hammer is driven to when the next print hammer is driven is v · T / 9, that is, 1 / (9 × 180) = 6.1.
7 × 10 ^-4 inches. Note that the 1 / D distance is shifted.
The moving time T is usually set to maximize the printing speed.
In addition, the repeatability of each print hammer,
Release from the holding position and print, then return to the suction holding position
It is designed to be equal to the time it takes to return.

In this embodiment, the distance between adjacent hammers is set to 0.1 inch (hereinafter, this pin arrangement position is referred to as a standard mounting position), and each print hammer is appropriately moved from each standard mounting position. They are only shifted. The shift amount of each of the print hammers 22 to 29 from the standard mounting position increases in accordance with the order in which the print hammers are driven. That is, the second driven printing hammer 22 is disposed at a position shifted by the shift amount x from the standard mounting position with respect to the first driven printing hammer 21 disposed at the standard mounting position. The third driven printing hammer 23 is disposed at a position shifted by 2x from the standard mounting position, and the ninth driven printing hammer 29 is disposed at a position 8x shifted from the standard mounting position. ing.

Here, the distance A from the print hammer 21 of each of the print hammers 22 to 29, the distance B which is the shift amount of each print hammer from the standard mounting position, and the adjacent left print hammer From the distance C (for example,
The distance between the print hammer 24 and the print hammer 29 in FIG.

[0022]

[Table 1]

By arranging the print hammers 21 to 29 as described above, the number of print hammers colliding with the paper is reduced to one.
/ 9 (up to 34 when 300 print hammers are installed)
), And the peak current value is reduced, so that a small-capacity power supply is sufficient. Further, since the mechanical impact is reduced, there is no danger that the printing quality is degraded. That is, a dot line printer with high printing quality can be provided at low cost.

Further, in the printing hammer arrangement of this embodiment,
As described above, since the distance C from the adjacent left print hammer is unified to 0.1 + 5x or 0.1-4x and arranged so as to have a substantially constant value, the magnetic interference between the left and right adjacent print hammers is reduced. There is also an effect that the influence is minimized.

Next, a case where three printing hammers are made into one group (three shifts) will be described with reference to FIG.

When three shifts are performed, these two groups 6
A print hammer assembly configured as a module with a single leaf spring in which six print hammers, which are the least common multiple of the number of dot rows L to be printed simultaneously and the number 3 of print hammers in one group, are connected below. 101. The assembly 101
Each of the printing hammers 31 to 33 is branched from an intermediate portion, and a printing pin is mounted on the upper end thereof through means such as welding or caulking. Numerical value 31 of each print hammer
Reference numeral 33 denotes the order of driving in each group, and 1 in the paper feed direction so that 6 dot rows can be printed at the same time.
The dots are shifted by rows, and are further shifted by a predetermined amount in the row direction, that is, in a direction perpendicular to the paper feeding direction, so as not to simultaneously collide with a printing paper (not shown).

In this case, the drive start timing pitch of each print hammer is t = T / 3, and the distance x that the hammer bank moves from when one print hammer is driven to when the next print hammer is driven is v. T / 3 or 1 / (3
× 180) = 1.85 × 10 ^-3 inches.

Accordingly, the distance A from the print hammer 31, the distance B from the standard mounting position, and the distance C from the left print hammer of each of the print hammers 32 to 33 are as shown in Table 2.

[0029]

[Table 2]

By arranging the printing hammers 31 to 33 as described above, the number of printing hammers colliding with the sheet can be reduced to one.
/ 3 (up to 10 when 300 print hammers are installed)
0), and the peak current value becomes smaller, so that a power supply having a smaller capacity is sufficient as compared with the half dot shift. Further, since the mechanical impact is reduced, there is no danger that the printing quality is degraded. That is, a dot line printer with high printing quality can be provided at low cost.

Finally, a case where four printing hammers are made into one group (four shifts) will be described with reference to FIG.

When four shifts are performed, these three groups 1
A print hammer set having a module configuration with one leaf spring in which two, that is, six, which are the number of dot rows L to be printed simultaneously, and twelve print hammers, which are the least common multiple of the number 4 of print hammers in one group, are connected below. The solid is assumed to be 102. The assembly 1
Each of the print hammers 41 to 44 in 02 is branched from an intermediate portion, and a print pin is mounted on an upper end thereof through means such as welding or caulking. Numeric value of each print hammer 41
To 44 indicate the order of driving in each group,
In addition, they are arranged so as to be shifted one dot line at a time in the paper feed direction so that six dot lines can be printed at the same time. Is provided.

In this case, the drive start timing pitch of each print hammer is t = T / 4, and the distance x that the hammer bank moves from when one print hammer is driven to when the next print hammer is driven is v. T / 4, that is, 1 / (4
× 180) = 1.39 × 10 ^-3 inches.

Accordingly, the distance A from the print hammer 41 of each of the print hammers 42 to 44, the distance B from the standard mounting position, and the distance C from the left print hammer are as shown in Table 3.

[0035]

[Table 3]

By arranging the print hammers 41 to 44 as described above, the number of print hammers colliding with the sheet can be reduced to one.
/ 4 (Up to 75 when 300 print hammers are installed)
), And the peak current value becomes smaller, so that a power supply having a smaller capacity is sufficient as compared with the half dot shift. Further, since the mechanical impact is reduced, there is no danger that the printing quality is degraded. That is, a dot line printer with high printing quality can be provided at low cost.

In this embodiment, six dot rows are printed simultaneously by one movement of the hammer bank. However, four or eight, twelve or twenty-four dot rows may be printed.

Further, in the present embodiment, a configuration has been described in which the position of the entire printing hammer including the leaf spring is shifted, and as a result, the printing position is shifted by changing the position of the printing pin. It goes without saying that the same effect can be obtained by setting the mounting position and shifting only the mounting position of the print pin.

Furthermore, the number of printing hammers in one group is set to odd number 9, 3, and even number 4. However, if it is an integer larger than 3, it is not necessary to limit the numerical value. The number of print hammers in the print hammer assembly having the module configuration may be the least common multiple of N and L or an integral multiple thereof. As described later, the numerical value N is more preferably an odd number than an even number.

That is, a printing hammer assembly having a module configuration in which N printing hammers in one group are integrally formed may be used. In this case, at least two types of printing hammer assemblies are required (when N is a divisor of L, ) And its manufacture and parts management are not easy.

If the module configuration is larger than the least common multiple (not an integral multiple of the least common multiple), the number of printing hammers per module increases, making it difficult to manufacture with high precision.

The reason why an odd number is desirable as the numerical value N will be described below.

First, the minimum pitch of the drive start timing in the case of an odd number is obtained by taking, as an example, a group of the nine print hammers. The drive start timing pitch of the nine print hammers is T / 9. Then, referring to the print hammer 25 adjacent to the print hammer 21, the print hammer 25 is arranged so as to be shifted by 4x from the standard mounting position. The distance from when one print hammer is driven to when the next print hammer is driven is x = v · T / 9, and in the case of the print hammer 25, 4x = 4v · T / 9. Therefore, the drive start timing pitch of the print hammer 25 is 4T / 9.

As described above, one group is assigned an odd number No (No
= 2no + 1: no is an integer of 1 or more), the minimum value t of the drive start timing pitch of adjacent print hammers
o can be obtained by to = no · T / (2no + 1).

On the other hand, the minimum pitch of the drive start timing in the case of an even number of the four print hammers as one group is determined. The drive start timing pitch of the four print hammers is T / 4. Then, referring to the print hammer 43, the print hammer 43 is shifted by 2x from the standard mounting position. Referring to the print hammer 42, the print hammer 42 is shifted by x from the standard mounting position. Therefore, the adjacent print hammers 42 and 43 are shifted by 2xx-x = x. Since the distance from when one print hammer is driven to when the next print hammer is driven is x = v · T / 4, when the print hammer 42 is driven to drive the print hammer 43, x = v · T / 4. v · T / 4. Therefore, the printing hammer 4
The drive start timing pitch of No. 3 is T / 4.

As described above, one group is set to an even number Ne (Ne
= 2ne: where ne is an integer of 2 or more), the minimum value te of the drive start timing pitch of adjacent print hammers
Is te = (ne-1) .T / 2ne.

It is apparent that the influence of magnetic interference and the like becomes smaller as the drive start timing pitch becomes larger, so that if to-te> 0 is satisfied, an odd number is preferable.

[0048]

(Equation 2)

Therefore, when the number is even, it is necessary to double the number of print hammers in one group to obtain a timing pitch equivalent to the drive start timing pitch when the number is odd. I understand. As a result, the hammer drive control becomes complicated, and depending on the number of print hammers, there is a risk that the work of modularization may not be easy.

[0050]

As described above, according to the present invention, the number of print hammers simultaneously colliding with paper is reduced to 1 / N, so that electrical and mechanical effects can be reduced, and a dot line printer of high print quality can be obtained. Can be provided at low cost. Further, since only one type of printing hammer assembly is required, the production and parts management thereof become easy.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a print hammer assembly used in a dot line printer of the present invention.

FIG. 2 is a perspective view showing an example of a spring charge type dot printing hammer.

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a front view showing another embodiment of the print hammer assembly used in the dot line printer of the present invention.

FIG. 5 is a front view showing another embodiment of the print hammer assembly used in the dot line printer of the present invention.

[Explanation of symbols]

10, 101 and 102 are print hammer assemblies and 21 to 2
9, 31 to 33 and 41 to 44 are printing hammers.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-216203 (JP, A) JP-A-4-263958 (JP, A) JP-A-57-87376 (JP, A) JP-A-4- 82758 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B41J 2/30 B41J 2/255 B41J 2/515

Claims (7)

(57) [Claims] 1. A plurality of dot printing hammers provided at predetermined pitches along a printing line and shifted at a time in a paper feed direction so as to print L (L is an integer of 3 or more) dot lines. Magnet means for generating a magnetic attraction force to hold the print hammer at the non-printing position, and provided corresponding to each print hammer to drive the print hammer, a pulse current of a predetermined width is supplied and Holding a release electromagnetic coil for canceling the magnetic field of the magnet means and the printing hammer,
A hammer bank that reciprocates along the row direction, wherein the hammer bank reciprocates and drives each of the print hammers to perform printing, wherein the print hammer is N (N is 3 or more). ), And the printing hammers of the number equal to an integral multiple of the least common multiple of L and N are integrally molded, and each printing hammer in the group has the same timing. To avoid colliding with the paper
The print hammer driven from the second to the nth in each group is the print hammer together with the other hammer.
For a standard mounting position when placed in the interval (n-
1) A dot line printer characterized by being provided shifted by / (ND). Here, D is the number of print dots per unit length. 2. When each of L and N is 6 and 3, respectively , and the driving start timing pitch of the printing hammer is t, each printing is performed.
Dot line printer according to claim 1, wherein the hammer is shifted t, characterized in that it has to be driven. 3. When the L and N are 6 and 4, respectively, and the driving start timing pitch of the printing hammer is t, the adjacent printing hammers are shifted by t or 2t according to the arrangement position thereof. The dot line printer according to claim 1, wherein: (4) Set up at a predetermined pitch along the printing line
At the same time, L (L is an integer of 3 or more) dot lines can be printed.
Dots that are staggered in the paper feed direction
A printing hammer and a method for holding the printing hammer in a non-printing position.
Magnet means for generating a magnetic attraction force for printing, and the printing hammer
Is provided corresponding to each print hammer to drive
A constant width pulse current is supplied to strike the magnetic field of the magnet means.
Holding the release electromagnetic coil and the print hammer,
A hammerbank that reciprocates along the row direction.
In the course of the reciprocating movement of the hammer bank, each of the above printing hammers is driven.
A dot line printer that prints by movingN (N is an integer of 5 or more)Duplicate consisting of pieces
Number of groups and each print in the group
Prevent the hammer from hitting the paper at the same time
Therefore, in each group, the second to nth drive
Moving the printing hammer,The printing hammer is different from other hammers.
For the standard mounting position when both are arranged at equal intervals
Displaced by (n-1) / (ND)And the group
Drive start timing pitch of adjacent print hammer in loop
Is defined by the following equationDot line characterized by the fact that
Printer. Where D is the number of print dots per unit length
Andt> T / N t: Drive start timing pitch of adjacent print hammer T: Time for the print hammer to move 1 / D distance. 5. The dot line printer according to claim 4 , wherein N is an odd number (N = 2no + 1; no is an integer of 2 or more).
Wherein the minimum value of the drive start timing pitch of the adjacent print hammers in the group defined by N is obtained by the following equation. to = no · T / (2no + 1) to: Minimum value of the drive start timing pitch of the adjacent print hammer T: Time for the print hammer to move a distance of 1 / D. 6. a and respectively 6 and 9, wherein L and N, when the driving start timing pitch of the printing hammer has a t, was set to adjoining printing hammer is shifted 4t or 5t are driven according to the sequence position The dot line printer according to claim 4, wherein: 7. A dot line printer according to claim 4, the N even numbered; and (N = 2NE ne is an integer of 3 or more)
Wherein the minimum value of the drive start timing pitch of the adjacent print hammers in the group defined by N is obtained by the following equation. te = (ne-1) .T / 2ne te: Minimum value of the drive start timing pitch of the adjacent print hammer T: Time for the print hammer to move a distance of 1 / D.