JPS58136453A - Hammer driving system for dot printer - Google Patents

Abstract

PURPOSE:To reduce uneven density of printing by making the input pulse width of a hammer driver so variable according to a power source voltage to minimize changes in the hammer drive current against changes in the voltage. CONSTITUTION:To monitor changes in the power source voltage, three voltage comparators are used to divide the power source voltage into four ranges. Under such a condition, as a printing timing is applied, a pulse with a width of T1, T2 or T3 is outputted according to the value of the power source voltage. Since, the output of the voltage comparators changes non-synchronously to the print timing, after a signal for decoding the output of the voltage comparators, a delay flip flop is placed to enter a set timing synchronizing the print timing while slightly preceding it. This varies the width of the input pulse to a hammer driver according to the power source voltage thereby minimizing changes in the hammer driving current.

Description

[Detailed description of the invention] The present invention mostly relates to a dot printer's hemma movement system.

As for the hen-V drive system of dot printers.

Conventionally, the one shown in FIG. 1 and the second factor has been used. The Dora F printer has as many driver circuits as there are one bins. If kanji can be printed, a dot serial printer should have 16 to 24 bins, and a dot/line printer should have several fil pins.

The number of bins varies depending on whether or not you print, but 68 bins are usually required. As the number of pins increases, the power capacity required to drive all the hammer bins at the same time increases accordingly, but when setting the power capacity value, it is not necessary to set the power capacity so that all bins can be printed at all times, but it is possible to print kanji characters continuously. Set it as follows. For this reason, when printing data that is close to pure black comes, the power supply is turned off and printing becomes impossible. In addition to this, a capacitor of large capacity is placed in parallel with the power supply, and the power supply voltage 1* is controlled so that printing is not performed when the voltage falls below a certain voltage. Therefore, printing is possible no matter what print data is received, but even if the power supply voltage fluctuates, the input pulse width to the hammer driver remains constant. I turtle, the peak value of the current fluctuates, and when the power supply voltage is high, the print density is dark, and the electric current m1i! When the c pressure was low, there was a drawback that the printing position became wider. In the case of a constant voltage type hammer driver, if the power supply voltage fluctuates, the hammer drive current value fluctuates accordingly, and the printing density becomes electrified, which is a drawback.
The present invention monitors the power supply voltage 8E and changes the power supply voltage according to the power supply voltage.
- By changing the input pulse width to the driver, fluctuations in the hammer drive current value are reduced, thereby providing a printer with less SNI during printing.

In the present invention, the hammer drive current is set to #L, and when the power supply voltage is high, the input pulse width to the hammer driver is narrowed, and when the power supply voltage EE is low,
The input pulse width is varied according to the power source FEK so as to widen the input coupler, so that the hammer driving current does not fluctuate even if the power source voltage fluctuates.

Next, embodiments of the present invention will be described with reference to drawings 1i.

*The hemmer driver used is shown in Figure 1 and Figure II2.

The following method is used to monitor the fluctuation noise of the power supply voltage and vary the input pulse width to the hammer driver according to the power supply voltage. First, in order to monitor fluctuations in the power supply voltage, a voltage comparison stage is used to divide the power supply voltage into four ranges. That is, the set value of the power supply voltage is v, and the set value of each of the eight voltage comparators is V.

Let V meeting sVl, in this case, V>V,>V proverb>V
Let it be s. As a result, the power supply voltage can be divided into four ranges: from V to V, from vl to V, from aVR to V, and from V to V.

Printing is not performed when the power supply voltage is va or less.

When V, or v, the input pulse width to the hammer driver is TIe When Vl is Vl, the input pulse width is 'r,, v,
to V, the pulse width is set to be T. At this time, Ta>Ta>Ta.

This is done by the method shown in Figure 4 or Figure 5, that is, prepare three pieces of one-piece and five-piece multi-pipe brakes,
Select the external capacitors Cs and IC1ecs so that their pulse widths are T, , T, , T-, respectively. Voltage ratio l for power supply voltage monitoring! Out of the two devices, the voltage ratio ffF is obtained when the set voltage is V, , V. If the total power supply voltage is V1 or higher, ThVl to v, e
v, decoded below.

The signal that causes the power supply voltage to rise above 6 has a pulse width T.

The one-seat multi-viprator with a one-seat multi-vibrator whose tube power supply voltage is from V to V, [the hail signal has a pulse width of T], and the one-seat multi-vibrator whose power supply voltage is less than V and whose hail signal is a pulse-Ta of one-sea Connect the wires to drive the multi-vibrator.

When a printing tie is applied in this state, a pulse with a pulse width of Ta, aT, or Ta is output depending on the electric pressure. Since the output of the voltage ratio [IL changes asynchronously and synchronized with the printing timing, the output of the voltage ratio I2 is changed after the decoding signal, and the 1 delay flip 7g is inputted, and the mark "Fl" is set regularly, and Please insert the print tie a little beforehand.Additionally, you can also use a programmable timer tube such as the 82S3 as shown in Figure 85 for a one-seat multivibrator. .At this time, 8253t-
Progera in advance! Set the pull-out Il'#) mode and set the pulse width T* VrOUT to OUT e.
It is necessary to load the pulse m T m to 0UTIK/(Russun T).

As described above, the present invention is configured so that the input pulse to the hammer driver can be changed depending on the power supply voltage, so that even if the power supply voltage fluctuates, the hammer drive current remains constant.
There is an effect that there is no fluctuation, and that the printing device does not become too PF.

[Brief explanation of drawings]

Figures 1 and 2 are hammer driver circuits used in dot printers, and Figures 3 and 5 are power supply voltage monitoring circuits used in an embodiment of the present invention. What about three different pulse widths? This is the circuit where this occurs.

Claims (1)

[Claims] In dot printers, the voltage method is used to drive the hammer, and when the hammer drive voltage is high, the pulse width input manually to the hammer driver is narrow, and when the hammer drive voltage is low, the pulse width input to the hammer driver is widened. Dot printer.