JPS59124880A - Serial printer - Google Patents

Abstract

PURPOSE:To enable to extremely easily correct a stagger of printing position in a forward-reverse direction, by a method wherein a hammer-driving circuit and a delay circuit are provided, and a manual adjusting means for adjusting a delay time of the delay circuit is provided. CONSTITUTION:To adjust the stagger of printing position, the delay circuit 21 is provided which is so constructed that when a printing-triggering pulse is outputted from a printing-triggering circuit 20, the timing of transmitting the pulse to the hammer-driving circuit 22 can be advanced or delayed by a previous adjustment. The delay circuit 21 is constituted of a manual adjusting means. Test printing is performed prior to printing actual data outputs, and when a stagger of printing is present, a variable resistor 31 is adjusted to eliminate the stagger, and thereafter the actual data outputs are printed, whereby the stagger in printing can be corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a serial printer, and in particular to a serial printer that allows easy manual adjustment when the printing position in the forward direction and the printing position in the reverse direction do not match. Related Prior Art and Problems As shown in FIG. 1, a serial printer is constructed so that a carrier 2 can move parallel to a platen 1. This carrier 2 is controlled by a space motor 4 via a drive belt 3ffi so that the stay shaft 6 fully slides and reciprocates by a feed screw gear 5 parallel to the platen 1. This carrier 2 has a print head mounted on a bracket 7. The print head is equipped with a dage type (petal type) type wheel 8, and the type wheel 8 is rotationally controlled by a rotation selection motor 9. By pressing the type wheel 8 in the direction toward the platen l in synchronization with the movement of the carrier 2 by driving the hammer plunger magnet 10, the type is impacted on the printing paper via an ink ribbon or the like (not shown). Letters, numbers, symbols, etc. are printed using printed characters on the dage-type type wheel 8 of the print head.

By the way, when a serial printer prints by moving the space drive at a constant speed, when printing is performed in both forward and reverse directions, there is a misalignment between the forward and reverse printing positions, resulting in problems with the alignment of the type. There is a drawback that alignment becomes worse, for example when printing all ruled lines or on the vertical axis of a graph. When printing, or when all of the thick shadow characters are lit by slightly shifting the entire type and typing twice, the vertical lines may not line up or the shadow characters may not be able to be printed thickly. There are problems such as

Possible causes of such poor alignment include variations in the space drive system such as play between the screw gear and the carrier, and variations in the hammer operating time. For example, if the hammer operation time is slow, printing will occur at points B and C in the forward and reverse directions, respectively, with respect to the printing position A in FIG. 2, resulting in a deviation of d.

In order to completely correct this misalignment, printing is performed only in the forward direction, or a large number of various sensors are installed and a processor constantly monitors the printing condition, and all positional deviations are corrected. Ta. However, the former method allows printing in only one direction, resulting in a slow printing speed, and the latter method requires complicated detection means and monitoring means, making it very expensive.

Object of the Invention The object of the present invention is to provide an inexpensive serial printer that can very easily correct all irregularities in printing position in the forward and reverse directions without using any printers that monitor all printing deviations. It is to be.

Structure of the Invention To achieve this object, the serial printer of the present invention includes a printing hammer drive circuit in a serial printer equipped with a carrier for holding a print head and a moving means for moving the carrier in forward and reverse directions. A hammer driving circuit and a play circuit are provided, and a manual adjustment means is provided for fully adjusting the delay time in the play circuit, and the unevenness of the printing position in the forward and reverse directions is adjusted by the manual adjustment means. shall be.

Embodiment of the Invention An embodiment of the present invention is shown in FIGS. 3 to 8.

Fig. 3 is a diagram explaining the occurrence of printing misalignment, Fig. 4 is a circuit configuration diagram of an embodiment of the present invention, Fig. 5 is an external view of a serial printer that is an embodiment of the present invention, and Fig. 6 is an explanation of the state of printing misalignment. 7 and 8 are explanatory diagrams of the printing misalignment correction state. In the figures, 20 is a trigger circuit, 21 is a play circuit, 22 is a hammer drive circuit, 23 is a switching transistor,
24 is a hammer magnetic coil, 25 diodes, 30 is a serial printer, 31 is a variable resistor, 3
2 is a digital switch. When the carrier moves, a transducer (not shown) rotates in response to this, and outputs the full sawtooth wave shown in FIG. 3 (0). Then, this is sliced at slice level H, and a printing trigger pulse shown in FIG. 3 is generated, which excites the hammer magnet coil. The movement waveform of this hammer is in the state shown in FIG. 3(c), and the type is hammered at the apex of the waveform and printing is performed.

Therefore, the printing position is the position shown by t in FIG. 3).

By the way, if there is no play between the carrier and the screw gear, as shown in Figure 3 0), the output of the transducer will coincide with the forward and reverse printing positions at intervals of a.However, if there is play, the amount of play will be △a. Therefore, there will be a difference between the results of printing in the forward direction and the printing in the reverse direction, resulting in uneven alignment.

In order to adjust this, the present invention provides a play circuit 21 as shown in FIG. The configuration is such that it can be adjusted in advance to be earlier than the current state, or in some cases to be later than the current state. This play circuit 21 is composed of manual adjustment means, and as shown in FIG. 5, a variable resistor 31 may be used, or all digital switches 32 may be used.

Before actually using the serial printer, printing is performed in forward and reverse directions.

At this time, for example, if there is play in the screw gear, see Figure 6 (a).
As shown in , the normal printing position PL coincides with the normal printing position P, but a lag occurs in the reverse direction printing position PR, and the printing position is shifted. Further, when the printer speed is slow, both the forward print position PL and the reverse print position PRI4 will deviate from the normal print position P, as shown in FIG. 6(b). Therefore, before using a serial printer for actual data output, test it and check for any misalignment7.And if the printing position is misaligned, as shown in Figure 6 (B) or Figure 7 (0), for example. In order to adjust the D/D circuit 210 time constant, the variable resistor 31 is manually adjusted to change its play time and thereby change the print hammer timing. As a result, the operation time of the υnomer drive circuit 22 is changed and the switching transistor 23 is
If the on-time is different, it is possible to print in the normal printing position as shown in Fig. 7 (b) and (c) even if there is an irregularity of D as shown in Fig. 7 (0). 7. If the printing condition at the time of the test is as shown in FIG. 6 (a) or (b), the play time is lengthened or shortened to delay or speed up the printing timing. As a result, the printing position is placed between P and PR in FIG. 6 (0), so that the printing positions can also be perfectly aligned.

Therefore, before printing all of the actual data output, perform all test printing, and if there is a printing deviation as shown in Figure 8 @n, adjust the variable resistor 31 and If the actual data output is printed after ensuring that the printing does not shift as shown in Figure (b), it is possible to correct any irregularities in the printed output.

Note that a digital switch 32 is used instead of the variable resistor 31.
If the time constant is adjusted after full use, the amount of adjustment can be recognized on a digital display.

Effects of the Invention According to the present invention, it is possible to improve the alignment (k) based on the results of forward and reverse printing using a manual adjustment means with an extremely simple configuration, and since it is not fixed, costs can be increased by increasing the precision of each part. It is possible to provide a very inexpensive serial printer with high print quality without having to worry about any costs.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the main parts of a serial printer, FIG. 2 is a diagram explaining the state of misalignment of the printing position, FIG. 3 is a diagram explaining the occurrence of misalignment in printing, and FIG. Fig. 5 is an external view of a serial printer which is an embodiment of the present invention;
The figure is an explanatory diagram of a printing misalignment state, and FIGS. 7 and 8 are diagrams explanatory of a printing misalignment correction state. In the figure, 20 is a trigger circuit, 21 is a play circuit, 22 is a hammer drive circuit, 23 is a switching transistor,
24 is a non-magnetic magnet coil, 25 is a diode, 30 is a serial printer, 31 is a variable resistor, 3
2 is a digital switch. ”;i=,=m

Claims (1)

[Claims] In a serial printer equipped with a carrier that holds a print head and a means of moving this carrier in the forward and reverse directions, a hammer drive circuit and a detent circuit are all provided to drive the printing hammer, and the delay time in this play circuit is 1. A serial printer characterized in that a manual adjustment means for all adjustments is provided, and any irregularities in printing positions in forward and reverse directions are adjusted by the manual adjustment means.