JPS6236875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for correcting frequency fluctuations in a printing device, and in particular, when detecting changes in the running speed of a printing device caused by fluctuations in power supply frequency by detecting type pulses, the present invention relates to a method for correcting frequency fluctuations in a printing device. The present invention relates to a frequency fluctuation correction method that calculates only the amount of fluctuation in the power supply frequency by canceling it out.

For example, in a printing device that prints by impacting the moving type with a hammer, such as a flying hammer type printing device, when the type traveling body is driven by an AC motor such as a synchronous motor or an induction motor. Furthermore, if the AC power frequency changes, the rotational speed of the AC motor changes.

In a flying hammer belt type printing device, as shown in FIG. 1, a type belt 2 on which a large number of type characters 1 are provided is driven by a drive pulley 3 in the direction of the arrow. The drive pulley 3 is driven by a drive motor 4 constituted by a synchronous motor. Then, when a specific magnet coil 5 is excited, a hammer 6 strikes the paper 7. This causes the paper 7 to strike the selected type 1 via the ink ribbon 8. A platen 9 is arranged inside the type belt 2 and presses the type belt 2, so that predetermined characters, symbols, etc. are printed on the paper 7.

A type pulse body 10 for detecting the position of each type 1 is provided below each type 1. The type pulse body 10 is detected by a type pulse body detector 11, and the pulse body 10 is configured to select a predetermined type character.
Therefore, based on the type pulse detected by the type pulse body detector 11, it is determined whether or not the drive speed of the type belt 2 is as specified, and the excitation start time of the magnet coil 5 is controlled accordingly. is required.

However, when the hammer 6 is driven by the magnetic coil 5 and strikes the paper 7, it generates vibrations with respect to the type belt 2, so that the type pulses generated from the type pulse body detector 11 are not affected by the type belt. Since jitter components based on the manufacturing precision between the type pulses 2 and the eccentricity of the pulley 3 are included, it is not possible to accurately control the driving time of the hammer 6 just by detecting the type pulses. Even if the hammer 6 is set to be considerably larger than the width of the type 1 as shown in FIG. 1, there is a drawback that a printer with good printing quality cannot be provided.

Therefore, an object of the present invention is to provide a frequency fluctuation correction method that can improve the problems caused by the presence of jitter and provide a printer with good print quality. In order to achieve this objective, the method for correcting frequency fluctuations in a printing apparatus of the present invention includes a type body that is driven by an AC motor energized by a commercial frequency and runs on a constant trajectory, and a type body that is integrated with the type body. a type pulse body detected by the type pulse body, a type pulse body detection means for detecting the passage of the type pulse body, a type pulse counting means for counting a plurality of predetermined number of type pulses obtained from the type pulse body detection means, and a reference speed. a standard time setting means for outputting a standard time signal indicating a standard time signal; and a running speed difference for detecting a time difference by comparing the time taken by the printing pulse counting means to count a predetermined number of printing pulses with the standard time of the setting means. Verification printing is performed by detecting means, means for delaying the type pulse by the time of the error based on the detected time difference, and driving and controlling the printing mechanism based on the type pulse sent by the delaying means. The apparatus is characterized in that it has a print control section and performs print position correction in response to frequency fluctuations of +2% to -4% of the commercial frequency.

First, in the present invention, a means for removing jitter components contained in a character pulse will be briefly explained.

As mentioned above, the jitter component contained in the type pulse is caused by the vibration of the type belt 2 when the hammer 6 is driven and the manufacturing and structural problems mentioned above. Therefore, due to the vibration of the type belt, the jitter component appears positive at one time, and the jitter component appears negative at the next cycle. And as a result of the experiment,
It has been found that the positive and negative magnitudes of this jitter component are approximately equal on average. In other words, when the jitter component caused by the vibration has a jitter amount of +J between certain character pulses, it has a jitter amount of approximately -J between the next character pulses. Therefore, it has been found that in order to eliminate the influence of the jitter component, the influence can be ignored by counting a plurality of character pulses.

Next, we will discuss the frequency fluctuation correction principle of the present invention in the second section.
This will be explained based on the diagram.

In FIG. 2, the horizontal axis is the time axis t, and the vertical axis shows the printing position l.

In Figure 2, the straight line ν ₁ indicates that the frequency fluctuation of the AC power source is 0.
The line ν ₂ shows the speed of the type belt when the frequency variation is -4%, and the line ν ₃ shows the speed when the frequency variation is -4%.
indicates the speed when the frequency variation is +2%. In general, AC power supplies are allowed to have frequency fluctuations in the range of +2% to -4%.

Let Tf be the time from the start of excitation of the magnet coil until the hammer strikes, that is, the flight time, and when the AC frequency fluctuation is 0, the hammer strikes at Tf after the excitation of the magnet coil starts. , l Printing will be performed at the ₀ position. However, if the power supply frequency of the drive motor fluctuates by _-α2 %, Tf after the start of excitation of the magnet coil
The position where the hammer hits is l ₁ , and l ₀ − l ₁ = △
This means that it will be printed at a position 1 in front of you. However, in this case, after the excitation of the magnet coil starts,
If the hammer can be controlled so that it presses when Tf + △t ₁ , the position when there is no frequency fluctuation is
Can be printed with l ₀ . Therefore, if this becomes possible, a printer with good print quality can be obtained even if the power supply frequency is reduced by α%. In this case, l ₀ =ν ₀ (Tf)=(1−α)ν ₀ (Tf+Δt ₁ ) Δt ₁ =α/1−αTf ……(1).

Also, among the type characters formed on the type belt, the nth type from the first type (nth digit type)
To print , the correction time △tn when excitation is started at time T _N that is Tn later than Tf is ln = ν ₀ (Tf + Tn) = (1 - α) ν ₀ (Tf + T _o + △t _o ) △ t _o =α/1−αTf+α/1−αTn =(Tf+Tn)α/1−α ……(2) Now let the number of digits of the hammer be n, and correct by fixing 1/2 of it as standard. Assuming that the time △tn is determined, the above equation (2) is as follows: △t _o = (Tf + Tn/2) (α/1 - α) ≒ (Tf + Tn/2) (α) ...... (3) ( 〓α is in the microsecond order, so α/1-α≒ 1) On the other hand, if we assume that the hammer is pressed at Tf when the power supply frequency fluctuates by +α ₃ % (α ₃ = 2), the print position will be l. ₂ , so in this case Tf
If the hammer can be controlled to strike at the time -Δt ₂ , good print quality can be obtained even in the case of such frequency fluctuations.

However, when the power supply frequency fluctuates up to +α% (α≦2), configuring the hammer to strike at a time △t ₂ earlier than the flight time Tf complicates control. Frequency fluctuations are based on the basic concept of setting the speed ν ₃ at which the frequency fluctuates by +2% as the reference speed (nominal speed), and making corrections when the frequency fluctuates by -6%. This is for correction. An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

In the figure, 20 is a type pulse counter, 21 is a correction pulse counter, 22 is a nominal value setting timer, 23 is a register, 24 is a correction time setting counter, 25 is a collation circuit, 26 is a J-K flip-flop, and 27 is a magnet. This is the net coil control section. The print pulse number counter 20 is configured to be cleared every time an even number of print pulses, for example 160, is counted. Note that the type pulse referred to herein is not the waveform as it is generated from the type pulse body detector 11, but is one that has been appropriately shaped. Further, the nominal value setting timer 22 is set such that when the drive motor 4 is rotating at the nominal speed, that is, when the type belt 2 is being driven at the rotation speed when the power supply frequency is +2% higher than the standard frequency, the type pulse is 160. The signal is set to be generated every time the signal is generated. This signal is a standard time signal indicating the reference speed.

Now, when the printer is driven, the above-mentioned type pulse is generated, and this is transmitted to the type pulse number counter 20, the correction pulse counter 21, and the correction time setting counter 24. At this time, the nominal value setting timer 22 starts operating with the first output pulse of the correction pulse counter 21. At this time, the set value Tk of the nominal value setting timer 22 is determined as follows.

The generation time tcc of the type pulse generated when the drive motor 4 is rotating at the standard frequency, that is, according to ν ₁ in FIG.
1000μs, flight time Tf = 1200μs, and the time Tn from the first digit to the nth digit of the type until the start of excitation is Tn = 800μs, then the correction time △t when the frequency fluctuation is +2% is: Δt=(1200+800/2)×(-0.02)=-32 μs. That is, if the frequency is +2% higher than the specified value, the pressing must be performed 32 μs earlier than in the normal case.

Therefore, when considering the speed when the frequency increases by +2%, that is, when α = +2%, the correction time is 32 μs (in the case of standard frequency).
When the frequency changes by -4% from the standard frequency, the correction time can be determined to be 96 μs.

The time tk for counting 160 print pulses when α=+2% is tk=(1-α)mtcc.

Here, since m=160, α=2%, and tcc=1000 μs, tk=156800 μs. Thus, the nominal value setting timer 22 is configured to generate an output pulse every 156,800 μs.

Therefore, when the drive motor 4 is currently being driven with the power supply frequency being -4%, the type pulse is
This occurs at a period of 1000 μs x 1.04 = 1040 μs. In order to eliminate the influence of jitter components, it is necessary to count an even number of print pulses, for example 160. Therefore, when 160 of these character pulses are counted by the character pulse number counter 20 as shown in FIG. 4, a time of 1040 (μs)×160=166400 (μs) is required. However, as mentioned above, the nominal value setting timer 22 has a set value Tk of 156800 μs.
The nominal value setting timer 22 is set so that when the printed character pulse is transmitted to the correction pulse counter 21, the correction pulse counter 2
Set by the signal output from 1, 156800
It operates to clear the correction pulse counter 21 after μs. Moreover, since the correction pulse counter 21 is configured to count with the standard pulse CL ₁ of 1 μs, the correction pulse counter 21 starts counting when the first print pulse is transmitted, as shown in FIG. starts, and when the count reaches 156,800, it is cleared once by the signal from the nominal value setting timer 22. Then, counting starts again, so when the print pulse counter 20 counts 160 print pulses, the correction pulse counter 21 counts 166400 (μs) - 156800 (μs) = 9600 (μs). The number 9600 will be entered in register 23.

On the other hand, a reference pulse CL ₂ of 10 ns is applied to the correction time setting counter 24 . The correction time setting counter 24 starts counting by the character pulse applied when the 9600 is written in the register 23, and counts the reference pulse _CL2 . And when this is counted 9600 times, matching circuit 2
5, when the number written in the register 23 and the number counted in the correction time setting counter 24 match, an output signal is generated, which is sent to the J-K flip-flop.
The signal is transmitted to the flop 26 to control the magnet coil control section 27.

At this time, the correction time setting counter 24
Since the reference pulse CL ₂ of 10 ns is applied, the time required to count 9600 pieces is 10 ns x 9600 = 96 μs, thus a correction amount of 96 μs is given, and the power supply frequency is -4 from the standard frequency. % fluctuation, that is, when the nominal frequency fluctuates by -6%, the magnet coil 5 is excited after a delay of 96 μs, and even if there is such a fluctuation in the power supply frequency, printing can be performed at almost the correct position. I can do it.

The value written in the register 23 is updated to a correction amount Δt' corresponding to the frequency fluctuation amount α at that time every time 160 character pulses are counted.

Moreover, the frequency fluctuation of a general commercial AC power supply is +2
% to -4%, and its fluctuation period is very large compared to the period of AC power supply, and does not change suddenly. For this reason, it is necessary to set the recycle time of the register 23 to an appropriate time that is neither too short nor too long so as to be able to follow the power supply frequency fluctuation amount α. As mentioned above, the number of character pulses and the time relationship of each clock are one example. Of course, the number of character pulses is not limited to 160 as described above, but can be selected to any other suitable number. Further, the reference pulse is not limited to only 1 μs and 10 ns as described above.

Further, although the present invention has been described with respect to a type belt type printer, it can also be applied to other types of printers such as a drum type printer.

As explained above, according to the present invention, by counting an even number of printing pulses, a state is created in which the influence of jitter is removed, and then correction can be made for power frequency fluctuations, resulting in extremely high printing quality. It becomes possible to provide printers.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a partial mechanism of the printer, FIG. 2 is an explanatory diagram of its operation, FIG. 3 is a configuration diagram of an embodiment of the present invention, and FIG. 4 is an explanatory diagram of its operation. In the figure, 1 is a type, 2 is a type belt, 3 is a drive pulley, 4 is a drive motor, 5 is a magnet coil,
6 is a hammer, 7 is paper, 8 is an ink ribbon, 9 is a platen, 10 is a type pulse body, 11 is a type pulse body detector, 20 is a type pulse number counter, 2
1 is a correction pulse counter, 22 is a nominal value setting timer, 23 is a register, 24 is a correction time setting counter, 25 is a verification circuit, and 26 is a J-K flip-flop.
The flop and 27 each indicate a magnet coil control section.

Claims (1)

[Claims] 1. A type body that is driven by an AC motor energized by a commercial frequency and travels on a constant trajectory, a type pulse body provided integrally with the type body, and a type pulse body that detects the passage of the type pulse body. a detection means, a type pulse counting means for counting a plurality of predetermined type pulses obtained from the type pulse body detection means, a standard time setting means for outputting a standard time signal indicating a reference speed, and the type pulse counting means. a running speed difference detecting means for detecting a time difference by comparing the time it takes for the computer to count a predetermined number of printed character pulses with the standard time set by the setting means; It has a printing control section that performs verification printing by driving and controlling the printing mechanism based on the printing pulse sent by the printing pulse and the printing pulse sent by the printing pulse, and has a frequency fluctuation of +2% to -4% of the commercial frequency. A method for correcting frequency fluctuations in a printing device, the method comprising correcting a print position in response to a change in frequency.