JPS63144060A - Recording paper feeder in recorder - Google Patents

Abstract

PURPOSE:To exactly detect the abnormality in paper feeding by a method in which the first pulse signal corresponding to the revolving number of motor and the second pulse signal of clock pulse are put in an incremental decremental counter, and on the basis of the count values, the normality or anomaly of paper sending is judged. CONSTITUTION:In making a power source, the initial value of an incremental/ decremental counter 14 is set up by a comparison reference count value circuit 15. When a desired speed is set up by a speed setting circuit 11, the output of a reference pulse oscillator 9 is divided by a divider 10 and sent out as a pulse signal. In case a DC motor 3 is stopped due to the blocking of paper, pulse signal from a photocoupler 8 disappears and only pulse signal from the divider 10 is applied to the counter 14. The count values can thus be counted and anomaly signal of paper feeding is sent out at a time when a comparison reference value is exceeded in a monitor 17, and the power source circuit 20 of the DC motor 3 is turned OFF.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording paper feeding device for a recorder, and more specifically, to a paper feeding abnormality detection means for detecting an abnormal condition such as a paper jam.

[Conventional example]

In Utility Model Application No. 57-157389, the present applicant has applied for a speed control circuit for a DC motor, which is particularly suitable for a paper feeding device of a recorder and is capable of accurately driving a DC motor at a predetermined rotation speed. . To briefly explain its configuration, a pulse signal corresponding to the rotational speed of the DC motor that feeds the recording paper and a clock pulse signal corresponding to the set paper feed speed are input to an up/down counter, and this counter is Addition is performed using a pulse signal, and subtraction is performed using the other pulse signal.A digital comparator compares a predetermined reference value with the counted value of the up-down counter, and the output of this comparator is used to control the DC motor. The power supply circuit is turned on and off as appropriate.

According to this, even in a device such as a recording paper feeding device where the load is likely to fluctuate, the DC motor can be driven with high rotational speed accuracy without requiring a PLL circuit (phase synchronized circuit) or the like.

[Problems to be solved by the invention]

However, if a paper jam occurs for some reason and the motor is unable to rotate even though the power to the DC motor is on, the DC motor or its power supply circuit may be damaged by excessive current. Furthermore, since the waveform to be measured for the liver and kidneys cannot be obtained, a problem arises in that the measurement must be restarted from the beginning.

These drawbacks are not limited to direct current motors, but also apply to synchronous motors and pulse motors.

[Problem that the invention seeks to solve]

In order to eliminate the above-mentioned conventional drawbacks, in this invention,
A motor that feeds the recording paper, an encoder that converts the number of rotations of this motor into a pulse signal, a reference pulse signal generation means that outputs a clock pulse signal corresponding to the set paper feed speed, and a pulse signal that receives one of the above pulse signals and adds them. And,
an up/down counter that receives and subtracts the other pulse signal, a comparison reference value setting means, and a monitoring means that compares the counted value of the up/down counter with the comparison reference value set by the comparison reference value setting means. We are prepared.

[Effect]

During normal paper feeding, the up/down counter receives one pulse signal and the other pulse signal alternately, adds and subtracts, and the counted value is kept almost constant.

When a paper jam or the like occurs and the motor cannot rotate, the pulse signal from the encoder is no longer input, and only the clock pulse signal is manually input to the up/down counter. As a result, the up/down counter can, for example, add -
When the count value exceeds the comparison reference value on the edge side, a paper feed abnormality signal is output from the monitoring means.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a recording paper feeding mechanism according to the present invention. According to this, the recording paper 1 is given an appropriate tension by a feed roller 2 and is sent out by a DC motor 3. The feed roller 2 is driven by a drive gear 6 provided on the shaft of the DC motor 3 via an intermediate gear 5. Further, a mirror plate 7 for reflecting light, for example, is attached to the shaft of the DC motor 3. This mirror plate 7 is provided with a large number of reflective parts and non-reflective parts alternately and radially around the axis so that a large number of pulses can be obtained during one rotation of the DC motor 3. For example, a photocoupler 8 for irradiating light onto the mirror plate 7 and detecting the reflected light is arranged at an appropriate distance from the mirror plate 7.

FIG. 2 shows a block diagram of an embodiment of a speed control circuit including the recording paper feeding mechanism. In the same figure, those designated by reference numerals 1, 3, 7, and 8 have the same structure as in FIG. 1 above.

The output of the reference pulse oscillator 9 is frequency-divided by a frequency divider 10 into pulse signals of a predetermined frequency. In this case, the frequency division ratio of the frequency divider 10 is determined by the speed setting circuit 11. The outputs of the photocoupler 8 and the frequency divider 10 are sent to a synchronous presettable amplifier down counter 14 via one-shot multivibrators 12 and 13, respectively. Here, it is desirable that the two one-shot multivibrators 12, 13 have approximately the same operating time. The output of the one-shot multivibrator 12 is supplied, for example, as a down-count clock to an up-down counter 14, and the output of the one-shot multivibrator 13 is supplied, for example, as an up-count clock. When one clock signal is at L level and the other signal changes from L level to H level, the up/down counter 14 performs an addition operation if the clock signal that has changed is an up count clock signal, and performs an addition operation if the clock signal that has changed is an up count clock signal, and performs an addition operation if the clock signal that has changed is an up count clock signal. is designed to perform a subtraction operation, and when one signal is at I (level), a counting operation is not performed even if the other signal changes from L level to H level signal.For this reason, one-shot multivibrator 1
The shorter the operating time of 2°13, the better.

The output of this up/down counter 14 is compared with a signal from a comparison reference count value circuit 15 in a digital comparator 16 . The signal sent out by the comparison reference count value circuit 15 is a fixed value, and the contents of the up-down counter 14 are also set to this value when the power is turned on. Regarding the up-down counter 14,
It is not necessarily set to this value, but may be set to another value, and the power supply circuit 20 of the DC motor 3 is controlled to be turned on or off by the output of the digital comparator 16.

As described above, the digital comparator 16 compares the fixed value from the comparison reference count value circuit 15 and the count value of the up/down counter 14, and controls the on/off of the power supply circuit 20 based on the comparison result. In addition to the digital comparator 16, a monitoring means 17 is provided which monitors the counted value of the up/down counter 14 and detects an abnormal state of paper feeding based on the counted value. That is, this monitoring means 17 compares the comparison reference value set by the comparison reference value setting means 18 with the count value of the up-down counter 14, and determines that there is a paper removal feed abnormality when the count value exceeds the comparison reference value. For example, the paper feed error indicator 19 is turned on and the power supply circuit 20 of the DC motor 3 is turned off.

Note that the error indicator 32 may be a buzzer or the like.

Next, the operation of this circuit configured as described above will be explained. When the power is turned on, the initial value of the up/down counter 14 is set by the comparison reference count value circuit 15. The set state is approximately 1/2 of the maximum count value of the up/down counter 14. In other words, if it is a decimal counter, it is desirable to set it to 50, for example, but as described above, the initial value may be set arbitrarily. Next, when the speed setting circuit 11 is set to a desired speed, the output of the reference pulse oscillator 9'' is divided by the frequency divider 10 and output as a pulse signal.Thereby, the output of the digital comparator 16 is Temporarily becomes BAA and power supply circuit 20
is turned on, the DC motor 3 rotates, and at the same time, the up/down counter 14 performs a subtraction operation due to the pulse from the photocoupler 8, and then the output of the digital comparator 16 changes to B≦A, and the power supply circuit 20 is turned off. However, in this case, if the feeding speed of the recording paper is high or if a magnetic core is used in the rotor of the DC motor 3, even if the power supply circuit 20 is turned off, the inertia will cause the DC motor 3 to may overrun. According to the circuit configuration of this embodiment, when such an overrun occurs, the overrun is subtracted by the up/down counter 14, so that the up/down counter 14 subtracts the overrun until the frequency divider IO finishes outputting the addition pulse corresponding to the subtraction area. During this period, the power supply circuit 20 is not turned on, so the DC motor 3 is also in a stopped state during this period. In this way, there is no sudden switching from OFF to ON, and no excessive force is applied to the chart paper feed mechanism including the DC motor 3, so the control circuit shown in this embodiment can be used at high speeds where overruns are expected. This is particularly effective when feeding the chart paper. In this embodiment, the rated rotational speed of the DC motor 3 is as follows.

Speed setting circuit 1 when driving a load such as recording paper
It goes without saying that the recording paper feed speed must be set higher than the recording paper feed speed set by 1.

In this case, the count value of the synchronous presettable up/down counter 14 is monitored by the monitoring means 17, and when the count value falls outside the comparison reference value set by the comparison reference value setting means 18, the monitoring means 17 A paper feed error signal is sent to the paper feed error indicator 19 and power supply circuit 20.

In other words, a paper jam occurs for some reason and the DC motor 3
If it stops, the pulse signal from the photocoupler 8 disappears, and only the pulse signal from the frequency divider 10 is applied to the up/down counter 14. As a result, the counter 14 performs an addition operation on the -side side, and the count value is counted up.

The counted value is compared in the monitoring means 17 with the comparison reference value set by the comparison reference value setting means 18, and
When the count value exceeds the comparison reference value, a paper feed abnormality signal is output from the monitoring means 17, and as a result, for example, the paper feed error indicator 19 lights up and the power supply circuit 20 of the DC motor 3 is turned off.

Contrary to the above, when the recording paper 1 is strongly pulled by some external force or when the rotation of the DC motor 3 is accelerated due to an abnormality in the power supply, the up/down counter 14 receives a signal from the frequency divider 10. Since the pulse signal from the photocoupler 8 is larger than the pulse signal, the count value of the counter 14 counts down, and when it exceeds the comparison reference value set by the comparison reference value setting means 18, the above-mentioned signal is sent from the monitoring means 17. An abnormal signal is output in the same way. In this sense, the comparison reference value setting means 18 sets the upper limit comparison reference value (
It is preferable to set two comparison reference values, for example, 100) and a lower limit comparison reference value (for example, -100).

FIG. 3 is a flowchart of signal processing when functions such as the comparison reference count value circuit 15, up/down counter 14, digital comparator 16, and monitoring means 17 in the embodiment shown in FIG. 2 are configured by a microcomputer. . To explain the procedure, (1) First, prepare the variables A, Fl, and F2, and
1=1. Initialize F2=1.

(2) If the logic potential of the output of the branching device 10 (hereinafter referred to as a reference pulse) is O, F1=0, and if the same logic potential is 1, F1=1 remains.

(3) If the logic potential of the output of photocoupler 8 is 0, F2
= 0, and if the same logic potential is 1, F2 remains as 1.

(4) In the case of F1=O, if the logic potential of the reference pulse has changed to 1, A=A+1 and Fl is also set to F1=1. F1
=1 and the logic potential of the reference pulse remains 0, bypassing this process.

(5) In the case of F2=O, if the logic potential of the output of the photocoupler 8 has changed to 1, then A=A-1 and F2 is also set to F2=1. If the logic potential of the output of the photocoupler 8 remains 0, this process is bypassed.

(6) Finally, if the value of A is A>O, the power supply circuit 20 is turned on, and if As2, it is turned off.

(7) And variable A is the lower limit of comparison standard value (-100)
It is determined whether <A<the upper limit of the comparison reference value (100), and if it is within that range, it returns to step (3), and if it is outside the range, it is determined that there is a paper feed abnormality, and the motor is stopped. Displays errors, etc.

Hereinafter, this step is repeated. In each step, the variable F1 is used to determine the input of the output pulse of the frequency divider 10, the variable F2 is used to determine the input of the output pulse of the photocoupler 8, and the variable A is the count value of the up/down counter 14. is equivalent to

In this configuration, the recording paper feed speed is 1c+a/sl, r
In this case, the feed pitch was 0.21111 or less and the feed accuracy was ±1%. In this invention, since the rotation of the DC motor is performed intermittently by starting and stopping, the first
In the recording paper feeding structure shown in the figure, gear 1. ．． 5.6
The larger the reduction ratio determined by, the better, and if possible, the effect of intermittent operation of the DC motor can be reduced by setting the recording paper feed amount per motor revolution to about 0.1 ma+.

The present invention can be applied not only to a DC motor but also to a recording paper feed device using a pulse motor, and a modification thereof is shown in FIG.
The pulse motor 23 is rotated at a predetermined number of rotations via the motor drive circuit 22 using the drive pulse from 1. This pulse signal is converted into a 7-up down counter 25.
For example, it is input as a down count clock to one input terminal of the clock.

A pulse signal from the reference pulse generating means 21 is inputted to the other input terminal of the counter 25 as, for example, an up-count clock. Note that this up-count clock signal may be a signal obtained by frequency-dividing the motor drive pulse by an appropriate frequency division ratio. This up/down counter 25 performs addition and subtraction using the two input pulses, and the counted value is maintained at a substantially constant value during normal paper feeding. As in the above embodiment, this counted value is compared with the comparison reference value from the comparison reference value setting means 18 in the monitoring means 17, but the pulse motor 23 stops due to paper jam etc. and the pulse signal from the encoder 24 disappears. However, when the up/down counter 14 counts up based on the pulse signal from the reference pulse generating means 21 and the counted value exceeds the comparison reference value, the monitoring means 17 outputs the paper feed error indicator 19 and the motor drive. A paper feed abnormality signal is output to the circuit 22. In addition, when the up/down counter 25 is a binary counter, the specific bit may be used as an abnormal signal. If this is done, the appearance of the monitoring means 17 and comparison reference value setting means 18 will be omitted. be able to.

〔effect〕

As is clear from the above description of the embodiments, according to the present invention, a first pulse signal corresponding to the rotational speed of the motor and a second pulse signal consisting of a clock pulse are input to an up/down counter, and Abnormalities in paper feeding can be accurately detected using a simple circuit configuration that subtracts with one pulse signal and adds with the other pulse signal, and determines whether paper feeding is normal or abnormal based on the counted value. The effect of being able to do this is produced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a recording paper feeding device of a recorder according to the present invention, and FIG. 2 is a block diagram showing an embodiment of the present invention.
FIG. 3 is a flowchart of signal processing in the embodiment shown in FIG. 2, and FIG. 4 is a block diagram showing another modification of the invention. In the figure, 1 is recording paper, 3 is a DC motor, 7 is a mirror plate, and 8
, 8 is a photocoupler, 9 is a reference pulse oscillator, 10 is a frequency divider, 11 is a speed setting circuit, 12.13 is a one-shot multivibrator, 14 is an up/down counter, 15
is a comparison reference count value circuit, 16 is a digital comparator,
17 is a monitoring means, 18 is a comparison reference value setting means, 19 is a paper feed error indicator, and 20 is a power supply circuit.

Claims (1)

[Scope of Claims] A motor for feeding recording paper, an encoder for converting the number of revolutions of the motor into a pulse signal, a reference pulse generation means for outputting a clock pulse signal corresponding to a set paper feeding speed, and one of the above. receive and add pulse signals, and
an up/down counter that receives and subtracts the other pulse signal; a comparison reference value setting means; and a monitoring means that compares the comparison reference value set by the comparison reference value setting means with the counted value of the up/down counter. A recording paper feeding device for a recorder, characterized in that the monitoring means outputs a paper feeding abnormality signal when the count value of the up/down counter exceeds the comparison reference value.