JP2002172808A - Dot line printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dot line printer for carrying out dot printing which improves various characteristics of a printing hammer while suppressing a peak current value of a coil current of the printing hammer and reducing power consumption. SOLUTION: A driving pulse for controlling a coil driving circuit for generating a coil current waveform is divided to multi stages from one stage in the prior art, so that the peak current of the coil current can be suppressed and the power consumption can be reduced. Further, the responsiveness of the printing hammer can be improved by a combination of coil specifications in which a rise of the coil current is improved. Accordingly, the dot line printer can be constituted by a necessary minimum arrangement to a required performance and can be improved in the cost performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dot line printer for performing dot printing with a plurality of printing hammers arranged in the digit direction, and more particularly to a control method for driving a printing hammer.

[0002]

2. Description of the Related Art A dot line printer is a typical printing device for performing dot printing.

A dot line printer is a printer that performs printing by reciprocating a hammer mechanism in which a plurality of print hammers for performing dot printing are arranged in the digit direction in a digit direction by a shuttle mechanism. The print hammer has a configuration in which a print pin is attached to the tip of a leaf spring. The print hammer is driven by releasing the bending energy previously given to the leaf spring, and printing is performed via an ink ribbon impregnated with ink. This is a printer that prints dots on paper.

Hereinafter, the configuration of a hammer mechanism in a conventional dot line printer and a drive control method of a print hammer when performing dot printing will be described in detail.

The hammer mechanism shown in FIG. 2 is of a so-called spring charge type. A hammer spring 2 having a hammer pin 1 joined to its tip is mounted on a yoke base 5 with bolts 8 together with the front yoke 6 on a magnetic circuit formed by the comb yoke 3, magnet 4, yoke base 5 and front yoke 6. I have.

Normally, the tip of the hammer spring 2 is magnetically attracted to the comb yoke 3 by the magnet 4 with a predetermined bending amount. Then, the bending of the hammer spring 2 is released by passing a coil current in a direction to cancel the magnetic attraction force to the hammer coil 9 attached to the comb yoke 3, and the hammer pin 1 hits the printing paper 12 via the ink ribbon 11. Performs dot printing.

FIG. 3 shows an example of a driving circuit for driving a printing hammer (a driving circuit for controlling the coil current of a hammer coil). In the figure, 21 is a power supply, 22 is a capacitor, 25 is a reverse blocking diode, and 26 and 27 are flyback diodes. In a dot line printer, for example, as disclosed in Japanese Patent No. 2890536, in order to reduce the size of a power supply, it is desirable to simultaneously drive a plurality of printing hammers arranged in the digit direction at the same time. In order to prevent this, a method is often adopted in which the printing hammer is divided into a plurality of groups, and the groups are driven at different timings.

FIG. 4 is a diagram showing a coil current waveform, a drive pulse for controlling a drive circuit for generating the coil current waveform, and a hammer striking force waveform. That is, the group control signal G applied to the bases of the plurality of group control transistors 23 shown in FIG. 3 and the print data signal P applied to the bases of the data control transistors 24 provided corresponding to the number of hammer coils 9 in each group. The waveform 33 of the coil current flowing through each hammer coil 9 is generated by the drive pulse generated by the above, and indicates that the striking force of the printing hammer corresponding to the change in the coil current can be obtained.

As shown in FIG. 4, the hammer pin 1 starts to operate with a time lag from the rise of the coil current, and after hitting the printing paper 12 via the ink ribbon 11 with the recovery of the magnetic attraction force, the hammer pin 1 initially recovers. To the suction position. In this example, the group control signal G <print data signal P has been described, but the group control signal G =
In some cases, the print data signal P is used.

[0010]

In order to obtain normal printing in a dot line printer, the striking force and repeatability of the printing hammer, that is, the coil current is supplied to the hammer coil 9 for all of the plurality of printing hammers. It is necessary to keep the time required for dot printing to return to the original suction position within a predetermined range.

Here, focusing on the impact force of the printing hammer, the coil current is lengthened, and the hammer coil 1 is started to operate, and the hammer coil is struck while the printing paper 12 is struck via the ink ribbon 11. If the coil current is set so that the current continues to flow through 9, the magnetic attraction force of the magnet 4 is continuously canceled,
The impact power tends to be higher. However, as apparent from the mechanism of the printing hammer, even if the coil current is increased for a certain period of time or more, the striking force does not increase but saturates.

On the other hand, focusing on the repeatability of the printing hammer, when the magnetic attraction force of the magnet 4 recovers immediately after the hammer pin 1 hits the printing paper 12 via the ink ribbon 11, the initial suction position after the hitting is improved. The return time before returning is shortened, and the repeatability of the print hammer is improved. From the viewpoint of reducing power consumption and heat generation, it is clear that it is more advantageous to make the coil current as short as possible.

In order to satisfy the required characteristics of the print hammer, that is, the hitting force of the print hammer and the repeatability, it is necessary to generate the coil current waveform while taking the above-mentioned items into consideration. A drive pulse for ON-OFF control of the coil current control transistor of
That is, the conditions are set such that the setting of the drive pulse including the group control signal G and the print data signal P is optimized. However, further improvement in cost performance and reduction in power consumption of dot line printers are required. For the hammer mechanism, high-speed printing hammer and low power consumption are required. It has become difficult to respond by methods.

For example, when an attempt is made to increase the speed of the printing hammer, it is conceivable to reduce the time lag from when the coil current is supplied to the hammer coil 9 to when the hammer pin 1 starts operating. For this purpose, it is conceivable to make the coil current rise steeply. In that case, however, the coil current waveform 34 shown in FIG.
As shown in (1), there is a concern that the peak value of the coil current will increase and the power consumption will increase, which has been a bottleneck in practical use.

As described above, an object of the present invention is to realize a drive control method in a dot line printer that suppresses the peak current value of the coil current of the print hammer, reduces power consumption, and improves various characteristics of the print hammer. It is to be.

[0016]

According to the present invention, there is provided a hammer spring having a hammer pin at a tip thereof, a plurality of print hammers arranged at a predetermined pitch, and a plurality of print hammers. A magnet that generates a magnetic attraction force to hold at a non-printing position, a comb yoke that holds the printing hammer at a non-printing position, and a corresponding to each printing hammer to drive the printing hammer, A hammer mechanism section comprising a hammer coil for supplying a coil current of a predetermined width to cancel the magnetic field of the magnet, a drive circuit for controlling the coil current of the hammer coil in accordance with a print duty, and a reciprocating motion of the hammer mechanism section in the digit direction. A dot-line printer having a shuttle mechanism for causing a paper to be fed and a paper feed mechanism for feeding printing paper. And a multi-stage pulse obtained by dividing the driving pulses applied to the drive circuit of the coil current supplied to the Le a plurality of pulses.

Further, in addition to the above configuration, the coil winding specification of the hammer coil may be set to a specification for improving the rise of the coil current.

According to the above configuration, it is possible to suppress the peak value of the coil current and reduce the power consumption. Further, by combining with the coil specification in which the rise of the coil current is improved, the response of the printing hammer can be improved. Therefore, the cost performance of the dot line printer can be improved.

[0019]

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

FIG. 1 shows an example of a coil current waveform 31 of a print hammer drive, a drive pulse for controlling a drive circuit for generating a coil current waveform, and a print hammer corresponding to a change in the coil current. 3 shows a waveform of a striking force. By dividing the group control signal G applied to the base of the group control transistor 23 out of the drive pulses into a plurality of coil signals as shown in the drawing, the hammer pin 1 controls the ink ribbon 11 while suppressing the peak value of the coil current. Until the printing paper 12 is hit through the control unit, the control is performed such that the magnetic attraction of the magnet 4 is canceled. Also,
As mentioned earlier, if the coil current is made longer than necessary,
Since the repeatability of the printing hammer deteriorates, the group control signals G,
And the print data signal P is set. In addition,
In this example, a case is shown in which the group control signal G is a three-stage pulse.

Further, by controlling as described above, the peak value of the coil current for driving the print hammer can be suppressed.
As shown in the coil current waveform 32, the rising of the coil current is made steep, the time lag from when the coil current is supplied to the hammer coil 9 to when the hammer pin 1 starts operating is shortened, and the response of the print hammer, that is, It is conceivable to improve repeatability. For that purpose, for example, the winding specification of the hammer coil 9 can be realized by changing the specification such as reducing the number of coil turns (number of windings) or increasing the coil wire diameter to reduce the coil resistance. It is.

The suppression of the peak value of the coil current for driving the print hammer, the reduction of power consumption, and the improvement of the response of the print hammer as described above are significant improvements in the cost performance of a dot line printer equipped with a large number of print hammers. Bring effect. Naturally, it is possible to reduce the size of the power supply by reducing the power consumption. However, by suppressing the peak current value, it becomes possible to use a low-grade transistor with a low rated current in a drive circuit of the print hammer. In addition, by improving the response of the printing hammer, it is possible to reduce the number of hammer pins required to obtain the printing speed set as a design value. Because you can
It is possible to configure a dot line printer that is more excellent in cost performance.

[0023]

As described above, according to the present invention,
The drive control method of the printing hammer is divided into a drive pulse for performing ON-OFF control of the coil current control transistor from one stage in the related art to multiple stages, thereby suppressing the peak value of the coil current and reducing the power consumption. It is possible to improve the response of the print hammer by combining with the coil specification that has improved the rise of the coil current, so that the cost performance of the dot line printer can be improved. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a coil current waveform and a hammer striking force waveform as an example of the present invention.

FIG. 2 is a sectional view showing a configuration of a hammer mechanism.

FIG. 3 is a drive circuit diagram for driving a printing hammer.

FIG. 4 is a diagram showing a coil current waveform and a hammer striking force waveform of a conventional technique.

[Explanation of symbols]

1 is a hammer pin, 2 is a hammer spring, 3 is a comb yoke, 4 is a magnet, 5 is a yoke base, 6 is a front yoke, 7 is a rear plate, 8 is a bolt, 9 is a hammer coil, 10 is a cooling fin, 11 is an ink ribbon, 12 is a printing paper, 13 is a platen, 21 is a power supply, 22 is a capacitor, 23 is a group control transistor, 24 is a data control transistor, 25 is a reverse blocking diode, 26, 2
7 is a flyback diode.

Claims (2)

[Claims] 1. A plurality of printing hammers, each of which is provided with a hammer pin having a hammer pin at a tip thereof and arranged at a predetermined pitch, and a magnet for generating a magnetic attraction force for holding the printing hammer at a non-printing position. A comb yoke for holding the print hammer at a non-printing position, and a hammer coil provided to correspond to each print hammer for driving the print hammer, and a coil current of a predetermined width is supplied to cancel the magnetic field of the magnet. A hammer mechanism, a drive circuit for controlling the coil current of the hammer coil in accordance with the print duty, a shuttle mechanism for reciprocating the hammer mechanism in the girder direction, and a paper feed mechanism for feeding print paper. A driving pulse applied to a driving circuit of a coil current supplied to the hammer coil. A dot line printer characterized by a multi-stage pulse divided into a number of pulses. 2. The dot line printer according to claim 1, wherein a coil winding specification of said hammer coil is set to a specification for improving a rise of a coil current.