CN1267871A

CN1267871A - Print density increasing methd for comb dot printer

Info

Publication number: CN1267871A
Application number: CN 99114108
Authority: CN
Inventors: 殷洪山
Original assignee: Nanjing Institute of Geography and Limnology of CAS
Current assignee: Nanjing Institute of Geography and Limnology of CAS
Priority date: 1999-03-17
Filing date: 1999-03-17
Publication date: 2000-09-27

Abstract

The present invention relates to improvement of printer circuit matched with core of marketed miniature dot printer. The print synchronizing sinusoidal signal output by the printer core is processed in frequency doubler, shaper and frequency divider before fed to monochip computer conrolling printer head. The print density and thus the working efficiency fare raised in the condition of no change in paper width and print speed.

Description

A kind of method that improves the comb dot printer print density

The present invention relates to comb dot printer,, under and the condition that print speed is constant wide, improve print density, thereby increase work efficiency at printer paper particularly to improving with the decline print circuit of type dot lattice printing machine core coupling of existing commercially available comb.

At present, the mini-printer that uses on many instrument and equipments is standard product, and the print density technical indicator was fixed after the printer core of every kind of model and print circuit matched.Be example with the domestic more Japanese EPSON company product that uses, the paper of M-150 type printer is wide to be 44mm, and the speed of printable character was 1 row/second, and it is 96 points that every row puts capable print density; The paper of M-160 type printer is wide to be 57mm, and the speed of printable character was 0.7 row/second, and it is 144 points that every row puts capable print density; The paper of M-164 type printer is wide to be 57mm, and the speed of printable character was 0.4 row/second, and it is 240 points that every row puts capable print density.Therefrom we can find that they have a common rule, and promptly print speed and print density are inversely proportional to.Can improve the print speed and the print density of printer simultaneously? analyze after deliberation, motor in the printer and gearing-down system design precision, be difficult for change, the raising print speed is difficult to realize on existing basis, but it is feasible fully to print synchronizing signal raising print density by change.

Purpose of the present invention is exactly the synchronous sine wave signal of printing of existing microprinting machine core output " to be carried out shaping earlier; sine wave is become square wave; and then carry out frequency division; obtain the printing synchronization pulse of actual use " this technical scheme is improved, take printing the first frequency multiplication of synchronous sine wave signal, the technical scheme of frequency division is carried out in shaping at last again, in making during effectively printing, more printed synchronizing signal, to reach under the constant prerequisite of print speed, improve the purpose of print density.

Concrete technical scheme of the present invention be the synchronous sine wave signal of printing with printer core output carry out exporting to after the process of frequency multiplication reshaper again behind the frequency division by the Single-chip Controlling printhead.Before frequency multiplier, also be provided with amplifier.Said frequency multiplier is that bridge rectifier output connects the amplifier formation.Frequency division adopts based on the computer software of single-chip microcomputer and realizes.In order to improve the dynamics of print needle bump colour band, adopt dutycycle based on the computer software control print coil on/off electric signal of single-chip microcomputer.

Below in conjunction with drawings and Examples, the invention will be further described.

Fig. 1 prints dynamo-electric block diagram for existing M-160 type;

Fig. 2 is the sequential chart of Fig. 1;

Fig. 3 is to the improved electric block diagram of M-160 type printer.

Fig. 4 is the sequential chart of Fig. 3;

Fig. 5 adds amplification enforcement circuit for the bridge rectifier of frequency multiplier;

Fig. 6 is for adding the circuit that triode amplifies before the frequency multiplier.

Be example now, introduce the concrete measure that improves print density in detail with M-160 type printer core.The M-160 type is a kind of 4 needle-comb type dot lattice printing machine cores.Its 6 of motor revolution one usefulness output supplies to print synchronous sine wave signal, and the rotating ratio that motor and driving are taken the lead between the sheave that moves is 18/1 (18 weeks of motor revolution, printhead round trip).So, in a printing interval, have 108 synchronous sine wave signals.Wherein have only 72 synchronizing signals after left positioning signal begins to use for printing, remaining 36 synchronizing signal appears in the printhead return course, is garbage signal.

Under the situation of 5V power supply, the cycle of printing synchronous sine wave signal is about 1.1ms.Consider the frequency of operation and the reliability of print needle, print synchronizing signal to 72 during work and carry out 2 frequency divisions that what reality was used is 36 printing synchronizing signals that are spaced apart 2.2ms.Like this, in a printing interval, each print needle can be made a call to 36 points at most, and 4 pins can be made a call to 144 points at most.Usually, realize the electronic circuit of this function, will print synchronous sine wave signal often earlier and carry out shaping, sine wave is become square wave, and then carry out 2 frequency divisions, obtain the printing synchronizing signal of actual use at last.Its theory diagram as shown in Figure 1, corresponding sequential is as shown in Figure 2.Among the figure, R exports reset signal for beating movement, and A is sinusoidal wave synchronously for printing, and B is a square wave after the shaping, and C is the actual printing synchronizing pulse ripple that supplies the Single-chip Controlling printhead behind the frequency division.

If will improve print density.In only during effectively printing, provide more printing synchronizing signal to realize.The present invention has adopted the printing synchronizing signal that M-160 is sent to carry out the circuit of frequency division after the first frequency multiplication, thereby obtains expecting the printing synchronizing signal of wishing.For example, if will obtain every row puts line printing 196 points, the printing synchronizing signal that M-160 can be sent is carried out 2 frequencys multiplication earlier, makes former 72 synchronizing signals of adopting become 144 synchronizing signals, and then these 144 synchronizing signals are carried out 3 frequency divisions, thereby obtain 48 synchronizing signals.Like this, in a printing interval, each print needle can be made a call to 48 points at most, and 4 print needles can be made a call to 192 points at most.In theory, the printing that can also obtain other with the method is counted.Its theory diagram as shown in Figure 3, corresponding sequential is as shown in Figure 4.Among the figure, R still is the reset signal of printer core output, and A prints sine wave synchronously, and B ' is the waveform after process of frequency multiplication, and C ' is shaping output, and D is the actual printing synchronization pulse that supplies the Single-chip Controlling printhead behind the frequency division.

The circuit of realization frequency multiplication has multiple, the invention provides a kind of simple and easy effective circuit.As shown in Figure 5.Its principle of work is as follows:

The AC sine wave A of printer output become a direct current pulsating volage B ', and the minimum value of this voltage is 0 through behind the bridge rectifier.This voltage signal is sent into transistor Q1 and is amplified after resistance R 1, R2 dividing potential drop.Suitably choose the current amplification factor of Q1 and the resistance size of resistance R 3, under the effect of input voltage signal, just can be met the high-low level signal of TTL interface needs from the collector of Q1.This signal is passed through IC again ₁C ' delivers to the counter input end of single-chip microcomputer after the reverser shaping, and D is to printhead for single-chip microcomputer output control signal.

Frequency division available hardware circuit is realized, also can be realized by software.From the angle of reduction of expenditure spending, it is more reasonable to realize with software.With current widely used INTEL8051 series monolithic is example, and the synchronizing signal of frequency multiplier circuit output is received the input end of one tunnel Timer of single-chip microcomputer, and this Timer is set to counting mode, and allows it to work under interrupt mode.When counter overflows the generation interruption, in corresponding interrupt service routine, be provided with and printing sign.Operate in the CPU under the master routine, by inquiring about this Status Flag, whether decision powers up to print coil, and then the motion state of control print needle.

For the certain model printer core output of printing synchronous sine wave signal peak value≤1.5V, in order to make the normal effectively work of frequency multiplier and follow up device, before being preferably in frequency multiplier amplifier is set, to improve the peak value of synchronous sinusoidal signal, as shown in Figure 6, before the bridge rectifier frequency multiplier circuit, also be connected to the symmetrical voltage amplifier.

Realized encrypted print by said apparatus.In a printing interval, the frequency of operation of having an injection has been accelerated many, even exceeds one times than former technical indicator.In such cases, can whether the dynamics of print needle bump colour band reduces, print literal and figure with practical value, and this is of paramount importance.Address this problem two approach: the one, suitably improve the operating voltage of print coil, 5V can be brought up to about 6V-7.5V.Other method is the dutycycle that changes control print coil energising/power-off signal.Both compare, and the latter is more simple in the power circuit design, and pass through the dutycycle of software or timing element change print drive signal, have simple, economy advantage.

The present invention carries out suitable frequency conversion process to the printing synchronizing signal of existing comb dot printer core output, and it is constant to have reached print speed, has improved print density.Can improve printing effect greatly, and can be applicable to the improvement of the comb dot printer of various models.

Claims

1, a kind of method that improves the comb dot printer print density is characterized in that the synchronous sine wave signal of printing of printer core output is carried out exporting reshaper to after the process of frequency multiplication, again behind the frequency division by the Single-chip Controlling printhead.

2, the method for raising comb dot printer print density according to claim 1 is characterized in that also being provided with amplifier before frequency multiplier.

3, the method for raising comb dot printer print density according to claim 1 and 2 is characterized in that said frequency multiplier is that bridge rectifier output connects the amplifier formation.

4, the method for raising comb dot printer print density according to claim 3 is characterized in that frequency division adopts the computer software realization based on single-chip microcomputer.

5, according to the method for each described raising comb dot printer print density among the claim 1-4, it is characterized in that adopting dutycycle based on the computer software control print coil on/off electric signal of single-chip microcomputer in order to improve the dynamics of print needle bump colour band.