JPS6013831B2 - Printing timing control method for printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing timing control method for a printing device having a type carrier, such as a line printer.

The printing device will be briefly explained with reference to FIG. 1, which shows a back impact printer.

A printing hammer 1, which is driven by an electromagnet 2 and returned to its initial position by a return spring 3, is attached to a printing paper 4.
And, via the ink ribbon 5, it faces the type 7 on the type carrier 6, which is made of, for example, a print band. The type carrier 6 is caused to travel at a constant speed by a drive pulley 9 and a driven pulley (not shown). The type mark 8 provided under each type 7 of the type carrier 6 is, for example, an electromagnetic pickup 1.
0' is detected, and this detection signal is used to determine the printing timing for driving the printing hammer 1, as will be described later. The detection signal of the pickup 10 is amplified by a waveform processing circuit 11 and converted into a type mark pulse shaped into a rectangular wave. The type mark pulse is generated by a printing timing adjustment means 12 that adjusts the printing timing so that the printing hammer 1 strikes the type 7 after a predetermined flight time has elapsed from the start of driving at the center of its striking surface, and the front surface of each printing hammer. A type code generator (hereinafter referred to as CCG) that generates the code of type 7 located at
13). The comparator 15 compares the print data code of the memory 14, which stores, for example, one line of print data code, with the print code of the CCG 13, and if they match, outputs a signal with a logic value of 1. The output of the comparator 15 is applied to the AND gate 1 at the timing of the output signal of the adjusting means 12.
6 to the printing hammer drive circuit 17 to energize the electromagnet 2 and drive the printing hammer 1. FIG. 2 is a diagram illustrating printing timing, and numeral 18 is a platen provided so as to face the EO hammer 1 via the type carrier 6, and extends along the printing position.

From the time the electromagnet 2 is energized until the printing hammer 1 strikes the type 7 after the flight time, the type carrier 6 moves a distance D.

Therefore, the timing for energizing the electromagnet 2 of the corresponding printing hammer must be when the type 7 struck by the printing hammer 1 appears a distance D from the center of the printing hammer. As mentioned above, the timing of energizing the printing hammer 1, that is, the electromagnet 2, is determined by the signal that detects the type mark 8, so the distance from the center of the printing hammer 1 to the corresponding type mark 8 is the distance D. Nearest type mark 8 under larger conditions
This distance is set as 〇. Assuming that the flight time tF is the time tF, the time from when the type mark 8 is detected until the electromagnet 2 is energized is tp, and the traveling speed of the type carrier 6 is v, the following relational expression holds true. D=v・tF...
""" (1} D' = v (tF + tp)...■ In other words, the timing at which the electromagnet 2 is energized so that the printing hammer 1 hits the type 7 to be printed is determined by the type mark 8.
This is after tp time has elapsed since the detection.

3 and 4 show the positional relationship between the striking surface of the printing hammer 1 and the printed characters when the printing hammer 1 strikes the type 7, where la is the striking surface and 7a is the paper 4. The characters printed on the , WH is the width of the hitting surface la, and Wc is the character 7a.
The width, L, and R are the distance differences between the striking surface la and the left and right ends of the character 7a.

It is assumed that the type carrier 6 travels toward the right side in the figure when viewed from the side of the type carrier 6 for printing. FIG. 3 shows the case where the time tp is adjusted to the optimum value, and FIG. 4 shows the case where the time tp is adjusted to be larger than the optimum value.

On the other hand, the flight time tF of the printing hammer is, as is well known,
When the driving voltage applied to the electromagnet 2 fluctuates or when the electromagnet 2
When the coil resistance value changes due to a rise in the temperature of the coil, or when the electromagnet 2 to be driven is affected by leakage magnetic flux from an adjacent electromagnet 2, etc.

When the flight time tF changes by ΔtF, the distance D'' that the type carrier 6 moves until the electromagnet 2 is energized and the printing hammer 1 hits the type 7 after time tp from the detection of the type mark 8 is: D′′=v(tp+tFshi△tP)...
...(3}, and a printing deviation occurs by △D'2 earth v・△tF with respect to the printing position of equation (2}. If the running direction of the type carrier 6 in FIG. 2 is clockwise, △tF When tF changes to 10 (plus), that is, tF changes to (tF + △tF), the print result shifts to the right as shown in Figure 4, and △tF becomes 1 (minus), that is, tF changes to (tF
-ΔtF), it will shift to the left.

By the way, as shown in FIG. 3, when the time t is adjusted to the optimum value, 〆L=〆R=(WH-WC)/
2...■, and the permissible variation limit of the flight time tF variation △tF, that is, the value that does not cause missing characters, is l△tFI<
It is expressed as (WH-WC)/(public)...'5).

In other words, the permissible fluctuation limit of flight time is "time t
It is defined as the maximum amount of variation in flight time that does not result in missing characters when p is adjusted to a light value. However, if the time tp has been adjusted from the beginning to a value as shown in FIG. 4, Equation (51) does not hold because so'L≠so'R (so'L>so'R).

For example, if there is a variation represented by a formula style, missing characters on the right side will occur in the case of Fig. 4. Similarly, if the initial adjustment value is ``So'L''R, missing characters on the left side will occur. FIG. 5 shows a specific example of the adjusting means 12, which includes a monostable multi-pipulator (hereinafter referred to as mono-multi) 21 for determining the printing timing, and a monostable multi-pipulator (hereinafter referred to as mono-multi) for determining the pulse width of the driving pulse of the electromagnet 2. It consists of a monomulti 22, an external capacitor 23 of the monomulti 21, an external variable resistor 24, a knob 25 for adjusting the resistance value of the variable resistor 24, and the like.

The values of the capacitor 23 and variable resistor 24 are C and R, respectively.
Then, there is the following relationship with the time constant tp of the monomulti 21. Note that K is a constant. tp=KCR・…・
(6) Therefore, by turning the knob 26, the time t can be changed, and the positional relationship between the striking surface la and the type 7 at the moment when the printing hammer 1 hits the type 7 can be adjusted. It becomes possible.

However, in such an adjustment method, it is very difficult to determine from the printed sample whether the positional relationship between the striking surface la and the characters 7a is closer to that shown in FIG. 3 or closer to that shown in FIG. 4.

For this reason, if the adjustment value of time tp causes the printing to be too close to one side of the striking surface la as shown in Fig. 4, when the flight time tF changes, missing characters or, in the worst case, omitted characters may occur. There was a drawback that there was.
An object of the present invention is to eliminate the drawbacks of the prior art and to make it possible to easily adjust the time tp so that missing characters will never occur as long as the variation in flight time is within the permissible variation limit. be.

In the present invention, if the time tp is adjusted to an optimal value so that the printing type is struck at the center of the striking surface of the printing hammer,
Focusing on the fact that missing characters will not occur as long as the amount of variation in flight time variation factors such as drive voltage and temperature is within the allowable variation limit for flight time, The present invention is characterized in that test printing is performed, and at this time, the time tp is adjusted so that missing characters do not occur by looking at the printed sample.

An embodiment of the present invention will be described below with reference to FIG. 6, which shows flight time variation factors as drive voltages.

30 is a drive power supply V.

and the printing hammer drive circuit 17, and the electromagnet 2
A power supply control unit that controls a drive voltage V applied to a control transistor 31, a control circuit 32, a reference power supply voltage 3
3. Consists of a switch 34, resistors 35 to 38, etc. The control circuit 32 controls the base current of the control transistor 31 so that the comparison potential on the resistor 35 and the potential Es of the reference voltage source 33 become equal. The resistance values of the resistors 35 to 38 are R, , R2, R3, and R4, and the emitter terminal voltage of the control transistor 31 when the switch 34 is turned to the 1 side, 2 side, and 3 side, that is, the drive voltage V
becomes.

However, R3>R4. If the flight time tF for each drive voltage V is set as follows,
When the changeover switch 34 is turned to the 2 side, the flight time becomes the allowable variation limit on the minus side, and when the changeover switch 34 is turned to the 3 side, the flight time becomes the allowable variation limit on the plus side.

Therefore, test printing is performed by energizing the electromagnet 2 with the changeover switch 34 turned to the 2 and 3 sides, that is, the flight time has fluctuated to the allowable fluctuation limit due to fluctuations in the drive voltage V. If the value of the variable resistor 24 is adjusted using the knob 25 so that missing characters do not occur in the print sample, the time constant tp of the monomulti 21 at that time becomes the optimum value. In other words, the value is such that missing characters do not occur even if the flight time fluctuates within the permissible fluctuation limit. In the above embodiment, in order to make it easier to understand the principle of the present invention, the positive and negative absolute values of the permissible flight time fluctuation limit were the same, but the positive limit value △tP (10) and the negative value Limit value △tF (1)
You can also sort by.

That is, tF■=tFlΔtF(-21-(WH-W
C) { l△ et al. (10) l+. btF(1)l}vtF{3'
The time tp may be adjusted as =tFl△tFke)l・(WH-Wc)

For practical use of the printing device, fluctuations in flight time due to decreases in the driving voltage of electromagnet 2 or increases in resistance due to increases in the temperature of the coil of electromagnet 2 are more significant on the positive side than on the negative side. Since it is large, it is more effective to divide and adjust it like this. In addition, although the drive voltage was considered a flight time variation factor, the resistance value of the electromagnet 2 was also used as a flight time variation factor. A variable resistor was connected in series with the coil of the electromagnet 2, and the flight time was varied by this variable resistance, resulting in printing timing. may be adjusted. As described above, according to the present invention, it is possible to accurately adjust the timing at which the printing hammer drive means starts operating, so even if the flight time varies slightly, the occurrence of missing characters is reliably prevented. . BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows an example of a printing device, and Fig. 2 is a side view of the printing section including a block diagram, Fig. 2 is a plan view of the printing section, and Figs.
The figure is a front view showing the striking surface of the printing hammer and the printing results.
The figure is a block circuit diagram showing a subsidiary example of the printing timing adjustment means, and FIG. 6 is a side view of the printing unit including the block diagram showing one embodiment of the present invention.

In the figure, 1 is a printing hammer, 2 is an electromagnet, 4 is paper,
6 is a type conveyor, 7 is a type, 8 is a type mark, 10 is an electromagnetic pickup, 12 is a print timing adjustment means, 17
is a printing hammer drive circuit, 21 and 22 are monomulti, 23
is a capacitor, 24 is a variable resistor, 25 is a knob, 30 is a power supply control section, 31 is a control transistor, 32 is a control circuit,
33 is a reference voltage source, 34 is a changeover switch, and 35 to 38 are resistors.

Figure 1 Figure 3 Figure 4 Figure 2 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. A type transporting body, a printing hammer, and a driving means for driving the printing hammer, the type being set to a certain value based on the detection of a type mark indicating the position of the type on the type type transporting body. In the printing device, the drive means starts operating to drive the printing hammer after the adjustment time has elapsed, and after the flight time of the printing hammer has elapsed, the printing hammer collides the printing type on the printing type carrier with the paper to print on the paper. , an adjustment means for setting the adjustment time from the detection of the type mark to the start of operation of the drive means, and for changing the flight time fluctuation factor of the printing hammer to the + side and the − side up to the permissible fluctuation limit of the flight time. comprising first and second means, and switching means for enabling either one of the first and second means,
Test printing is performed in each state in which the flight time variation factor is changed to the + side and - side permissible fluctuation limits of the flight time by the first and second means, and during this test printing, missing character printing and A printing timing control method characterized in that the adjustment time is adjusted and determined via the adjustment means so that the adjustment time does not change. 2. The printing timing of the printing device according to claim 1, wherein the adjustment time is set by a monostable multivibrator, and the adjustment means is constituted by an external variable resistor of the monostable multivibrator. Control method. 3. The printing timing of the printing device according to claim 1, wherein the flight time variation factor is a drive voltage applied to the drive means, and the drive voltage is varied up to a permissible flight time variation limit. Control method. 4. Claim 4, characterized in that the flight time variation factor is the resistance value of the drive means, and a variable resistor is connected in series with the drive means to vary the variable resistance up to a permissible variation limit of the flight time. A printing timing control method for a printing device according to item 1. 5. The method according to claim 1, wherein the value of the first means for changing the flight time variation factor to the positive side is set to be larger than the value of the second means for changing the flight time variation factor to the negative side. Printing timing control method for printing device.