JPS5912474B2 - printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides high-quality, uniform printing by using a type wheel that can reduce mutual interference between the operating states of a plurality of hammers whose operating states interfere with each other. The purpose of the present invention is to provide a high-speed printing device with high performance and efficiency.

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a printing device according to the present invention, in which numeral 1 denotes a type wheel that continuously rotates and has a plurality of characters in the circumferential direction, and is arranged in the direction of the rotation axis by the number of digits; Its shaft, H is a support 5 supported by a support member 8, a plastic printing hammer provided at the tip of a holding spring 5, 3 is a solenoid with a coil wound around an iron core inserted into the printing hammer, 4 is a printing hammer A permanent magnet 6 forms a working magnetic field, and a rotatable ink roller 1 is provided in contact with the type wheel 1.
0- and T are stain prevention plates that prevent the printing paper 9 from touching the type ring and becoming dirty.

Figure 1A shows the printing standby state, and the solenoid 3 having an iron core receives a force in the direction of the permanent magnet 15 due to the printing hammer operating magnetic field (hereinafter referred to as "magnetic field") formed by the permanent magnet 4. The printing hammer is biased to the printing standby position against the force received from the support spring 5.

The opening in Figure 1 shows the printed state.

When a predetermined type 10 on the rotating type wheel 1 comes to a position facing the printing hammer 2, the solenoid 3 is energized. When the solenoid is energized, it is excited with the same polarity as the permanent magnet as shown in the opening of Figure 1, and the printing hammer receives force in the direction of the printing wheel due to the change in the force received from the magnetic field, and the printing paper 925 is pressed against the type 10, and the ink applied to the type 10 by an ink roller is transferred onto the printing paper, thereby printing is performed.
At the same time as the printing hammer 2 presses the printing paper 9 against the type 10, the energization to the solenoid 3 is stopped, and the marking 30 character hammer is again biased to the printing standby position.

Reference numeral 10 is an organic elastic sheet made of rubber or the like which has various functions such as preventing demagnetization due to impact on the permanent magnet, preventing coil breakage, silencing noise, and allowing the hammer to move easily even when the amount of current applied to the coil is reduced.

Further, 3511 is a yoke which not only holds the magnet but also has the function of strengthening the magnetic field. Next, a detailed explanation of the operation mode of the printing hammer will be given using the operation diagram shown in FIG.

As shown in FIG. 1, the displacement of the printing hammer 2 from the printing waiting position is assumed to be X.

Further, the force that the printing hammer receives is F, the force in the direction of the printing wheel is +D, and the force in the direction of the permanent magnet 4 is negative (-F). That is, if the sum of the forces F applied to the printing hammer 2 is positive, the printing hammer moves in the direction of the type wheel 1, and if it is negative, it moves in the direction of the permanent magnet. In FIG. 2, the X-axis is the displacement of the printing hammer, the F-axis is a coordinate axis representing the force applied to the printing hammer, point 0 is the waiting position of the printing hammer, and point A is the printing position.

A again. -C1' each represents the force that the printing hammer receives at the displacement x. That is A.

is the force that the printing hammer receives from the support spring, which is zero at printing position A, maximum at waiting position 0, and B. is the force that the hammer receives from the magnetic field when the solenoid 3 is not energized, and has a minimum force at print position A and a maximum negative force at standby position 0. C again. is A. and B. In this embodiment, the combined force is set to be negative at all positions of the printing hammer movable displacement, so that the printing hammer is stably biased to the printing waiting position. Also, when the solenoid is energized, the printing hammer receives a force B from the magnetic field due to the interaction between the magnetic field and the solenoid. changes to b1. C, is A
. By setting the spring constant, the solenoid magnetomotive force, and the strength of the magnetic field so that it becomes a positive force, the printing hammer moves toward the type, and printing is performed. The kinetic energy (printing energy) required for the printing hammer to reach the printing position A is the line segment 0A-C1 and FI4l.
It is clear that it is expressed by the area of the part surrounded by the line lx=A. FIG. 3 shows a perspective view of the printing hammer unit in this embodiment.

This embodiment is a 13-digit printing device, but the printing hammer is
By not using the printing hammers H-10 and H-14 at both left and right ends, the other 13 printing hammers H-1
~ Consideration has been given to making the operating conditions of H-13 uniform.

In this embodiment, a plurality of printing hammers with iron cores are arranged in the magnetic field formed by one permanent magnet, so when one printing hammer is activated, the other printing hammers are affected. This is easily imagined.

of The mutual interference of this type of printing hammer will be explained below.

The solenoid 3 and the permanent magnet inserted into the printing hammer 2 form a magnetic circuit as shown by the arrow at the front of Figure 1.

Reference numeral 11 denotes a yoke provided on the permanent magnet, which constitutes a part of the magnetic circuit.

As shown in Figure 1A, P is the permeance due to one printing hammer when the solenoid is not energized yet and the printing hammer is biased to the printing standby position. , is the permeance PA when the printing hammer is still in the vicinity of the printing position immediately after the end of energization of the solenoid, as shown in FIG. 1. Further, when the permeance during the time when the solenoid is energized is y, PO>PA>0 P'=0.

As shown in FIG. 3, when all 15 printing hammers H-0 to H-14 are biased to the printing standby position, the total permeance ΣPO of the magnetic circuit is ΣPO=15P0.

In addition, as shown in the opening of Figure 1, the total permeance XPA of the magnetic circuit when n printing hammers (n≦13) are at the printing position immediately after energization is completed is ΣPA=(15-n
)PO+NPA, and ΣPO−ΣPA=n(PO−PA
) the permeance of the magnetic circuit decreases.

f shown in FIG. 4 is a demagnetization curve of the permanent magnet 4. Due to a decrease in permeance, the operating point of the permanent magnet changes from g to h, and the magnetic field strength of the magnetic circuit increases.

In addition, when the solenoids of n printing hammers are energized, the total permeance Σp' is p/=o.
As a result, the permeance decreases further and the magnetic field strength also increases significantly.

When the magnetic field strength of the printing hammer operating magnetic field increases, the printing hammer receives a force B shown in FIG.

,b,,Cl are each B. ',b1',C,', and the printing energy and the moving speed of the printing hammer are reduced. In this example, since a ferrite magnet with a small reversible magnetic permeability (μ=1) is used as a permanent magnet, the magnetic field strength of the entire magnetic field does not increase uniformly as described above, but in reality, The magnetic field strength increases with a distribution having a peak at the position of the printing hammer at the printing position or the position of the energized printing hammer.

Therefore, if adjacent printing hammers are operated at the same time, printing quality, efficiency, etc. will deteriorate. FIG. 5 shows the printing energy and printing time that the printing hammer H-7 of the 8th digit receives when the printing hammer H-7 of the 8th digit and other printing hammers are operated simultaneously in the printing unit of this embodiment. Show the impact of

The printing time is the time from when the solenoid starts being energized until the printing hammer reaches the type. Fifth
As is clear from the figure, when multiple printing hammers are activated at the same time, the printing energy of the 8th digit q printing hammer H-7 decreases and the printing time increases, but when the same number of printing hammers are activated, It can be seen that if the positions are far apart, the influence will be small.

Figure 6 shows the influence of the printing hammer that was activated first on the operating state of the printing hammer that activated later when two adjacent printing hammers are activated with a time difference, and the printing energy and energy of the printing hammer that activated later. Indicated by printing time.

The horizontal axis in the figure is the time difference between the operation of the two printing hammers.
As is clear from FIG. 6, when the time difference becomes shorter than the printing time, both printing energy and printing time begin to be affected rapidly. This means that the adjacent printing hammers reach the type,
If the next printing hammer is activated before the current is turned off, it will have a significant effect. In order to avoid mutual interference between printing hammers, it is ideal to operate only one printing hammer at a time and to allow sufficient time before activating the next printing hammer, but this has the disadvantage of slowing down the printing speed. Occur. Taking all of the above into account, in this embodiment, the number of printing hammers that are operated simultaneously is small and the number of printing hammers is set as far apart as possible, and the time difference between adjacent printing hammers is set as large as possible before they are activated. By using a type wheel that can provide a time lag larger than the printing time [゛0] and the energization time to the solenoid before activating the solenoid, the printing speed is not reduced and mutual interference of the printing hammers is reduced.

FIG. 7 shows a type arrangement of a type wheel according to the present invention.

In the conventional type wheel, as shown in Fig. 7A, the same type letters are arranged in the same position in the circumferential direction in each digit axis direction, and as shown in the figure, the arrangement position of the same type letters in the circumferential direction is arranged in a circle by the unit pitch P. Even if they are shifted in the circumferential direction, immediately adjacent girders are only continuously shifted by a pitch P, so that the above-mentioned object of the present invention cannot be fully achieved.

In the present invention, as shown in FIG. , each of which is arranged by shifting it by a unit pitch P along the circumferential direction.

In other words, C is an example in which the print position is shifted by 10 pitches and returned to its original position to make one cycle.The print character "1" jumps two digits from the first position, shifts by the unit pitch P to the second position, and then returns to the original position by two digits. Fly to the 3rd position, shift pitch by 2P, then fly 2 more digits and get 4
It is shifted by pitch 3P to the position of number, and then 5 ~ [phase]
are inserted into the first two digits, shifted by the unit pitch P, as before, and arranged as shown. Figure 2 is an example of a 5-pitch cycle in which every other digit is assigned a value. FIG. 8 shows a timing chart when printing all digits "1" in the type arrangement shown in FIG. 7-2.

In Fig. 8, timing pulses 1-1, 1-2, etc. are obtained by timing pulse generators provided coaxially with the type wheel, and as shown in Fig. 7 2, the timing pulses correspond to each type, and the solenoid is energized. This is a signal used to specify the start time.

When printing digit 7f61, timing pulse 1-
When the solenoid of the printing hammer H-1 starts to be energized in synchronization with 1, the printing hammer H-1 moves toward the type wheel and prints ``1'' at the character position 1.

When the power supply to the solenoid of the printing hammer H-1 is stopped at the same time as printing, the printing hammer H-1 receives the timing pulse 1.
It returns to the print waiting position at around -3.

Also, adjacent digits. Since the operation of the printing hammer H-2 of 462 is started in synchronization with the timing pulse 1-4, a time difference of l is obtained from the end of printing of digit 7f61. Furthermore, the operation of the printing hammer H-3 of the girder 3 is started in synchronization with the timing pulse 1-2, but a blank time is provided so that it does not overlap with the energization of the girder A6l, as shown by m in the figure. In addition, since there is a printing hammer H-2 of the girder 2 in between, the operating state of each hammer is hardly affected.

Also, the maximum number of printing hammers that can be operated simultaneously is three.

From the above, it is understood that the type arrangement of the present invention enables a reliable and efficient high-speed printing device with less mutual interference between digits.

[Brief explanation of the drawing]

Figure 1 shows an embodiment of the present invention, Figure 2 is a diagram explaining the operation of the printing hammer, Figure 3 is a perspective view of the hammer unit, and Figure 4 is the demagnetization of the permanent magnet. Characteristics, Fig. 5 is a graph showing the results of measuring the effect of simultaneous operation of printing hammers on a specific digit, Fig. 6 is a graph showing the results of measuring the effect of the operating time difference of adjacent printing hammers on a specific digit, Fig. 7 Figures A and 7 show an example of a conventional type wheel arrangement, Figures 7C and 2 show an example of a character arrangement according to the present invention, and Figure 8 is a timing chart when printing all digits of "1". 1:... type wheel, 2... hammer, 3...
...Solenoid, 4...Permanent magnet.

Claims (1)

[Claims] 1 A permanent magnet common to a plurality of digits, a plurality of printing hammers that are attracted to the permanent magnet, and a plurality of printing hammers that are provided corresponding to each of the printing hammers and generating a magnetic field that opposes the magnetic field of the permanent magnet to cause the printing hammer to A printing device characterized by comprising a plurality of coils for selective operation and a type ring arranged corresponding to the printing hammer, in which identical type characters in the digit direction are arranged offset from each other in the circumferential direction. .