JPS602197B2 - dot matrix printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to high speed dot matrix printers.

Dot matrix printers can print multiple
This printer has a print head equipped with wires and records dots through a printing operation in which each print wire collides with a printing paper, and characters are expressed by a collection of these dots.

The printing operation of a conventionally used dot matrix printer will be explained with reference to FIGS. 1 and 2.

FIG. 1 shows the configuration of a print head of a dot matrix printer. When a driving pulse is applied to the printing magnet 1, the armature 2 is attracted to the printing magnet. The armature 2 pushes the print wire 3 and the print wire collides with the print paper 5 via the print ribbon 4. At this time, dots are printed by the print wire 3. When the drive pulse disappears, the print wire 3 and the armature 2 are pulled back by the return spring 6, and they collide with the damper 7, causing the print wire 3 and the armature 2 to stop with several vibrations due to the damper 7 and the return spring 6. do. The relationship between the displacement x of the print wire 3 and the drive pulse at this time is shown by a solid line in FIG. Dots in Figure 3
An example of a pattern is shown.

The second row of dots has a one-space interval, the sixth row of dots has a two-space interval, and the lqth dot row has a three-space interval.

The dot columns in each row in FIG. 3 are printed by the same print wire 3 while moving laterally at different times. Therefore, by the dot pattern as shown in Figure 3,
The period at which the print media 3 is driven varies.
The dotted lines in FIGS. 2 and 4 indicate the second dot printing operation at a different period. In the case of Figure 2, the print wire 3 is in the printing direction, that is, when the next drive pulse is applied at a phase where it has a positive speed. This shows a state in which a driving pulse is applied in the direction of The kinetic energy of the print wire 3 at the time of the first collision is greater than that at the first collision.

However, in the case of the second printing operation in Figure 4, the initial speed is negative, so the print speed when it collides with the paper is
The kinetic energy of the wire 3 is smaller than the first collision. As in the case of Fig. 4, when a driving pulse is applied with a negative velocity component, the energy of the second collision becomes smaller than the energy of the first collision, and falls below the predetermined printing energy. Normal dot printing becomes impossible.

Therefore, an object of the present invention is to provide a dot matrix printer that can perform stable printing operations regardless of the dot pattern.

That is, in the present invention, by changing the waveform of the drive pulse according to the printing interval of dots, the printing operation of the printing element is ensured and a predetermined printing energy is ensured. The present invention will be explained in detail below with reference to Examples. FIG. 5 shows a circuit configuration of an embodiment of the present invention.
8 is a character pattern generation circuit for generating character patterns.

9-1 to 9-N are dot pattern discrimination circuits for determining the interval between the currently printed dot and the next printed dot.

This dot pattern discrimination circuit 9 is provided one by one corresponding to each row of dots constituting a character pattern, and determines the interval between dot patterns in each row of the character pattern.
Numerals 10-1 to 10-N are arbitrary pulse generating circuits for generating drive pulses corresponding to the dot spacing determined by the dot pattern determining circuit.

The drive pulse generated by the arbitrary pulse generation circuit 10 is triggered by the signal S-01 from the position detector 11. - Pupil detector 11 detects that the print head is in the vertical position shown in FIG. 3 and generates signal S-0.
12-1 to 12-N are magnet driver circuits for amplifying drive pulses from the arbitrary pulse generating circuit 10, and 1-1 to 1-N are printing magnets shown in FIG.

FIG. 6 shows an example of the structure of the dot pattern discrimination circuit 9.

Reference numeral 13-1 is a shift register, and data is shifted to the right in the figure by the signal S from the position signal detector.

Input signal S-1 to shift register 3-1 is provided by character pattern generator 8. 14-17 are NAND circuits, and 18-21 are inverter circuits.

The discrimination results of the dot pattern discrimination circuit 9-1 from .largecircle., . . . to D, .K are as follows, for example, depending on the contents of the shift register 13-1. 13a 13b 13c...
...D,, D,2 D,30 〇 〇 〇〇〇1
〇 〇 〇 〇〇0 1 〇 〇 〇〇11 0 10○ 〇 〇 1 0 0○ 1 ○ 1 ○1○ ○ 11 〇 〇〇111 10〇In other words, when the value of 13a is 1, the dot pattern Depending on the interval, when the interval is 1, the output of D, , becomes 1, and when the interval is 2, the output of D, , 2 becomes 1.

In the same way, depending on the spacing of the dot patterns,
,3 outputs D,,K. The configuration and operation of dot pattern discrimination circuits 9-2 to 9-N are the same as those of 9-1. FIG. 7 shows an example of the configuration of the arbitrary pulse generation circuit 10. 22 to 25 are NAND circuits, and 26 to 3
7 has a delay time of 71, 1'72'1. ．．・．． ．．・7
3.K is a mono-staple multi.

Further, 38 to 41 are NOR circuits. This is the signal from the S-river bond layer signal detector. D,,, to D,,K are signals from the dot pattern discrimination circuit 9, and are NAND
The circuits 22 to 25 select one of D, , K from D, , depending on the interval of the dot pattern using the signal S. Now, the interval between dots is 1, and D,,
．． is selected, the position signal S-0 causes the mono
Staple multi 26 is triggered. At the falling edge of the output Q of the mono-stabilized multi 26, the mono-stabilized
The bull multi 27 is triggered, and similarly, the falling of the output Q2 of the mono steady multi 27 causes the mono steady multi 28 to be triggered. Q, and N of the output of Q3
When the OR is performed by the NOR circuit 38, Q is obtained. The above explanation took the example of the case where the signal of the dot pattern discrimination circuit is D, .
Steeble Multi 29-31...35-37
operates, and signal Q4 is generated. A time chart regarding the above operations is shown in FIG. In the figure, Q acts as a driving pulse to the print wire, and Q3 acts as a braking pulse to damp vibration after printing. Depending on the spacing of the dot pattern, the vibration of the print wire is suppressed.
By setting the delay time 2, 73 of the mono/stabil/multiple, it becomes possible to apply the next drive pulse under optimal conditions. FIG. 9 shows an example of the position detector 11 and a position detection method.

45 is a light source.

46 is the print head shown in FIG.

44 is an encoder, which has slits corresponding to the vertical lines of the dot pattern shown in FIG.

43 is a sub slit for creating moiré with the slit of the encoder 44.

42 is a photo transistor for detecting the brightness of light.

11 is a position detector for shaping the signal of the phototransistor.

The print head 46 and encoder 44 are connected by a belt,
The encoder 44 rotates due to the movement of the print head 46,
Photo transistor 42 generates an output in response to a change in position, and position detector 11 generates signal S-0 which serves as a trigger for driving the dot wire. The printing operation of the dot matrix printer according to the present invention will be explained.

Conventionally, as explained in FIGS. 2 and 4, the printing magnet was driven with the same driving pulse regardless of the dot printing interval. If the dot printing interval is as shown in Figure 2, the printing energy will be large and the printing will be good, but if the dot printing interval is as shown in Figure 4, the printing energy will fall below a predetermined value. Fear arises.

Therefore, the dot pattern discrimination circuit 9 discriminates the next dot printing interval from the signal of the character pattern generation circuit described above, and generates the optimum drive pulse according to the dot printing interval from the arbitrary pulse generation circuit. Occur.

When the first dot and second dot have a relatively long dot printing interval as shown in FIG. 10, the return operation of the wire may be delayed, and it is better to reduce the repulsion at the damper 7.
In this case, as shown in FIG.
After time 72 returns, a driving pulse is again applied to the printing magnet 1 for a time 3 to reduce the collision speed at the damper 7 and the repulsion at the damper 7.
When such a driving pulse is applied to the printing magnet 1, when the second regular driving pulse is applied, the vibration in the damper 7 has almost subsided and the waveform 45 becomes like the waveform 46, and the waveform 2 shown by the dotted line It has no negative effect on the second action. However, in the case of a relatively short printing interval as shown in FIG. 2, if a driving pulse is applied even at the time of recovery as shown in FIG. 10, the recovery operation will be delayed and high-speed printing operation will not be possible.

In this case, it is also effective in the present invention to apply only one drive pulse as in the conventional case. In order to select whether or not to apply these driving pulses, a dot pattern discrimination circuit 9 shown in FIG. 5 is required. Next, other embodiments of the present invention will be described. The circuit configuration is the same as that of the embodiment shown in FIG. 6, but the configurations of the dot pattern discrimination circuit 9 and arbitrary pulse generation circuit 10 are different. In order to simplify the configuration of these circuits, the number of drive pulses generated from the arbitrary pulse generation circuit is limited to two types. One is the drive pulse only when accelerating the print wire 3 as shown in Figure 2, and the timing of the second peak of the 1-hour displacement characteristic when the dot interval is single printing as shown in Figure 2. This is a case that occurs before. The other case, as shown in FIG. 10, is when the dot spacing occurs between the second peak and the second trough, and the print wire 3 is returned to its original position by the drive pulse that accelerates it and the return spring. , that is, when two braking pulses are applied to dampen the motion between the first peak and the first trough. If the number of drive pulses generated by the above-mentioned arbitrary pulse generation circuit 10 is limited to two types, the dot pattern discrimination circuit 9 only needs to determine which of the above two types of drive pulses to specify. The configuration of the discrimination circuit 9 is simplified. In this case, the dot pattern discrimination circuit 9 in FIG.
9 is sufficient, and the arbitrary pulse generating circuit 10' or N in Fig. 7 is sufficient.
AND circuits 22, 23, mono stable multi 26
, 29 to 31 and NOR circuits 38 and 39 only.

However, the input to the NAND circuit 14 is NA instead of 13b.
It is necessary to input the output of ND circuit 15. Even if the drive pulses are limited to the two types described above, the effects such as the effect of reducing the collision speed at the damper 7 and the repulsion at the damper 7 described in the first embodiment can be achieved by a single type. This is remarkable compared to the pulse case. In addition, since the dot/pulse discrimination circuit 9 applies a braking pulse only at the dot spacing that requires braking the print wire 3, the power consumption of the printing magnet is lower than when braking pulses are applied at all dot spacings. It becomes less.

The dot matrix printer of the present invention
The pattern discrimination circuit 9 determines the next dot printing interval by looking at the character pattern generation circuit 8.
Since the optimal drive pulse according to the dot printing interval is outputted from the arbitrary pulse generation circuit 10, good printing conditions are achieved at all dot printing intervals, which eliminates dot printing defects and dot fading, resulting in high-quality dot printing. becomes possible.

In the above explanation, only the printing of character patterns has been described, but it is well known that dot matrix printers can print not only characters but also figures such as straight lines, curves, patterns, etc., and the present invention It can also be applied not only to character patterns but also to graphic patterns, allowing for high-quality graphic printing.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of the print head of a dot matrix printer, Figure 2 is a waveform diagram showing the relationship between print wire operating characteristics and drive pulses, Figure 3 is a diagram showing an example of a dot pattern, and Figure 3 is a diagram showing an example of a dot pattern. FIG. 4 is a waveform diagram showing the relationship between the operating characteristics of a conventional print wire and drive pulses when the printing interval is long, and FIG. 5 is a circuit configuration diagram showing an embodiment of the present invention.
FIG. 6 is a block diagram showing an example of a dot pattern discrimination circuit, FIG. 7 is a block diagram showing an example of an arbitrary pattern generation circuit,
FIG. 8 is a time chart of the operation of the arbitrary pattern generation circuit, FIG. 9 is a schematic configuration diagram showing the position detector and position detection method, and FIG. 10 is a diagram of the print wire according to the present invention when the printing interval is long. A waveform diagram showing the relationship between operating characteristics and drive pulses. Figure Cheek Noku Diagram

Claims (1)

[Claims] 1. Generating the dot pattern in a dot matrix printer having a plurality of printing elements arranged in a predetermined manner and a driving means provided on the printing elements and driving the printing elements in accordance with the dot pattern to be printed. a pattern generating means for detecting the interval between dots to be printed for each printing element based on the dot pattern output from the pattern generating means; A dot matrix printer characterized in that the dot matrix printer comprises means for generating pulses for each element, and said driving means is driven by said pulses.