JPH07164706A - Carrier driver - Google Patents

Abstract

PURPOSE:To eliminate disorder of printing immediately after the printing is started by providing motor drive control means, etc., for controlling suppression of vibration of a carrier by controlling conduction of a motor based on the output signal period information. CONSTITUTION:When it becomes a time set to a control data table of a ROM in case where a printing head is driven, a step rate corresponding to the time is read, and a carrier motor is controlled to be driven at each one step based on its conduction pulse. The motor is accelerated up to an F point, and becomes a constant speed from the point. An initial damping pulse is supplied at an E point during accelerating, thereby suppressing a vibration of the carrier after the E point. A next damping pulse is supplied at the F point where the motor is shifted from the acceleration to the constant speed, thereby further suppressing the vibration of the carrier during the constant speed after the F point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier drive device in which a motor reciprocates a carrier in one direction via a carrier belt.

[0002]

2. Description of the Related Art A carrier driving device of this type is, for example, a carrier driving unit of a serial printer or a CCD of a scanner.
(Charge Coupled Device) Provided in a sensor drive unit, a pen drive unit of a plotter, and the like.

For example, a carrier driving device provided in a carrier driving portion of a serial printer is a carrier that can reciprocate in one direction, a carrier belt that reciprocates the carrier, and a carrier that penetrates the carrier to guide the reciprocating motion of the carrier. A motor that drives the shaft and the carrier belt is provided.

In such a carrier drive mechanism,
When the motor is driven, it is desirable to move the carrier according to the operation of the motor, but in reality, the carrier vibrates due to the elastic characteristics of the carrier belt and the sliding friction between the shaft and the carrier, and Can not follow the action of.

In order to suppress the vibration of the carrier, conventionally,
When the carrier vibrates, the carrier moves at low speed (idling) until the vibration is sufficiently damped, and then the carrier is normally driven to print.

Further, the motor is actually driven and a damping pulse having a predetermined pulse cycle at an appropriate timing (one of the motor drive pulses, which is especially supplied to the motor to suppress carrier vibration). To check if the carrier vibration was suppressed, and if it is not suppressed, repeat the work of changing the supply timing and size of the damping pulse to cut the carrier Vibration was suppressed.

[0007]

However, in such a conventional example, when the carrier vibrates, the motor is driven at a sufficiently low speed to idle the carrier until the vibration is attenuated.
After that, since the motor is normally driven to start printing, there is a problem that it takes a long time to run idle and the device becomes large by the amount of the traveled distance, and the size cannot be reduced.

[0008] Such carrier vibration remarkably appears particularly when shifting from acceleration to constant speed. For this reason, even if the driving is started at a low speed, vibration occurs when accelerating to the normal speed to a constant speed, and there is also a problem that the printing immediately after the start of printing is disturbed.

Furthermore, since the timing for supplying the damping pulse is determined by cut-and-try,
There is also a problem that it is difficult to supply the damping pulse at an appropriate timing.

Therefore, the present invention intends to provide a carrier driving device capable of appropriately suppressing the vibration of the carrier, eliminating the print disturbance immediately after the start of printing, and further reducing the size of the device itself. To do.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a carrier driving device for moving a carrier capable of reciprocating in one direction via a carrier belt by a motor, and energizing the motor according to the elapsed time when the motor is driven. Then, the energization control information storage means for storing the energization control information for controlling the motor from acceleration to constant speed, and the speed displacement of the carrier are measured in advance, and the speed displacement of the carrier and the speed of the motor when no load is applied. Based on the displacement, the positional deviation between the carrier and the motor is calculated, and the vibration suppression that stores in advance the signal cycle information of the vibration suppression signal to be supplied to the motor and the supply timing of the vibration suppression signal is calculated based on the positional deviation. The energization control information is extracted from the signal information storage means and the energization control information storage means according to the elapsed time when the motor is driven. Performs drive control of the constant speed from the acceleration by performing the energization control of the motor based on the distribution, when the elapsed time reaches the supply timing of the vibration suppressing signal,
There is provided motor drive control means for taking out signal cycle information from the vibration suppression signal information storage means, controlling energization of the motor based on the signal cycle information, and performing vibration suppression control of the carrier.

[0012]

In the present invention having such a structure, when the motor is driven, the energization control information is retrieved from the energization control information storage means according to the elapsed time, and the energization control of the motor is performed based on this energization control information. While performing drive control from acceleration to constant speed, when the elapsed time reaches the supply timing of the vibration suppression signal, the signal cycle information is taken out from the vibration suppression signal information storage means, and the motor cycle based on this signal cycle information is taken out. Conduct energization control.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a serial printer will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a schematic structure of a carrier driving unit of a serial printer according to the present embodiment. Reference numeral 1 is a print head for outputting print data to a print sheet, and 2 is a print head 1 mounted on the print head. A carrier provided so as to be capable of reciprocating in one direction, 3 is a shaft for guiding the reciprocating movement of the carrier 2, 4 is a carrier belt to which the carrier 2 is fixed,
A carrier motor 5 drives the carrier belt to move the carrier 2.

The carrier belt 4 is wound around pulleys 4a and 4b provided at both ends of the carrier belt 4, and the carrier belt 4 is driven by driving one pulley 4b by a carrier motor 5. . The carrier motor 5 is composed of, for example, a 4-phase pulse motor,
Drive control is performed based on energization control information for acceleration and deceleration, which will be described later, a pulse cycle of a damping pulse for suppressing vibration of the carrier 2, and a supply timing.

This damping pulse is applied to the carrier motor 5
The position displacement and the velocity displacement of the carrier 2 are detected in advance in order to obtain the timing of supplying the pulse to the carrier and the pulse period of the damping pulse.

In this case, a linear encoder sensor 6 is provided in the carrier drive section. This linear encoder sensor 6
Specifically, is composed of a linear slit 6 a provided along the moving direction of the carrier 2 and an encoder sensor 6 b provided on the carrier 2.

This encoder sensor 6b is shown in FIG.
Further, the position displacement and the displacement direction are detected by the two-phase output of A phase and B phase as shown in (b). Further, the motor control unit 14 controls the A-phase, B-phase of the carrier motor 5,
Corresponding to the C phase and the D phase, FIG.
Drive signals as shown in (b), (c), and (d) are supplied to the carrier motor 5.

The drive signal from the motor controller 14 is
Input terminals A, B, C of the measured value calculation circuit 21 shown in FIG.
The encoder sensor 6b outputs the detection output of the encoder sensor 6b to the input terminal ENCA and the input terminal ENCB.

The measured value calculation circuit 21 outputs the velocity displacement of the carrier 2 as shown by the dotted line graph in FIG. 12 from the output terminal Q1 based on the detection output from the encoder sensor 6b.

Further, the measured value calculation circuit 21 outputs the speed displacement of the carrier motor 5 when the carrier motor 5 is unloaded, based on the drive signal from the motor control unit 14, at the output terminal Q.
It is designed to output from 2. This velocity displacement is, for example, as shown by the solid line graph in FIG.

Further, the measured value calculation circuit 21 integrates the velocity displacements of the carrier motor 5 and the carrier 2 to obtain their position displacements, and calculates the position deviations shown by the solid line graph of FIG. 13 from these position displacements. Then, the signal is output from the output terminal Q3.

FIG. 2 is a block diagram showing a schematic configuration of the serial printer according to the present embodiment. 11 is a CPU (central processing unit) that constitutes the main body of the control unit, and 12 is the CPU 11 for controlling the drive of the carrier motor 5. ROM (read only memory) in which the program data and the like are stored in advance, 13 is a RAM (random access memory) in which various memory areas for storing data processed by the CPU 11 are formed, 14 Is the above carrier motor 5
Is a motor control unit for driving the print head 1, and 15 is a print head control unit for driving the print head 1.

The CPU 11, ROM 12, RAM 1
3. The motor control unit 14 is connected to each other via a bus line 16 such as an address bus, a data bus, and a control bus.

The CPU 11, the ROM 12 and the motor controller 14 constitute a motor drive control means.

The ROM 12 is provided with a control data table 22 as shown in FIG. The control data table 22 serves as both energization control information storage means and suppression signal information storage means. That is, the energization control information, the pulse cycle of the damping pulse, and the supply timing are set in the control data table 22.

The energization control information is information on acceleration, deceleration, etc. supplied from the CPU 11 to the motor control unit 14, and the pulse cycle and supply timing of the damping pulse are based on the position deviation from the measured value calculation circuit 21. It is calculated by

The control data table 22 is specifically composed of a time area 22a and a step rate area 22b. Then, the drive elapsed time of the carrier motor 5 is set in the time area 22a, and the drive pulse corresponding to the time set in the time area 22a is set for each step of the carrier motor 5 in the step rate area 22b. ing.

For example, the first step indicates that a motor drive pulse having a pulse period of 5 ms is supplied to the carrier motor 5 until the drive elapsed time of the carrier motor 5 is 0 to 5 ms. When the reciprocal of this pulse period of 5 ms is taken and expressed as the step rate converted into the number of pulses per second,
It becomes 200 PPS (pulse / sec).

In the second step, the drive time of the carrier motor 5 is from 5 to 8.14 ms, and the pulse cycle is 3.14.
It is shown that a motor drive pulse of (8.14 to 5.00) ms is supplied to the carrier motor 5. If the step rate is calculated by taking the reciprocal of this pulse period of 3.14 ms and converting it to the number of pulses per second, 318 PPS (pu
lse / sec).

The fifteenth step shown by the solid line arrow in the figure corresponds to a damping pulse, and the drive period of the carrier motor 5 is from 26.11 to 27.78 ms and the pulse period is 1.67 (27.78-26. 11) It shows that a pulse of ms is supplied to the carrier motor 5. The step rate converted to the number of pulses per second by taking the reciprocal of the pulse period of 1.67 ms is 600 PPS.
(Pulse / sec).

With respect to the relationship between the pulse period and the step rate, when the time is plotted along the abscissa and the step rate is plotted along the ordinate, as shown in FIG. 7, the damping pulse is almost linear until the 14th step. The step rate decreases at the set fifteenth step.

The timing of supplying such a damping pulse is determined as follows and is preset in the time area 22a of the control data table 22.

First, in the velocity displacement of the carrier motor 5 and the carrier 2 as shown in FIG. 12 output by the measurement value calculation circuit 21, the first damping pulse causes the carrier 2 to reach the maximum with respect to the velocity displacement of the carrier motor 5. Supply at the point of being late.

That is, specifically, the carrier 2 is closest to the final step of acceleration of the carrier motor 5.
The time at the point E where the speed displacement (dotted line graph) of 1 and the speed displacement (solid line graph) of the carrier motor 5 coincide with each other is set as the supply timing of the damping pulse.

The point where the carrier 2 has the maximum delay is set as the damping pulse supply timing in the following manner. That is, generally, if the damping pulse is supplied to the carrier motor 5 only for the time until the carrier 2 returns to the convergence position of the carrier 2, the delay of the carrier 2 is eliminated. However, if the damping pulse is supplied to the carrier 2 because the delay of the carrier 2 is small, the pulse period of the damping pulse becomes extremely short, which may cause the carrier 2 to lose synchronization.

The pulse period of this first damping pulse is calculated as follows, converted into a step rate, and preset in the control data table 22.

When the carrier motor 5 is driven, the frictional force between the shaft 3 and the shaft hole of the carrier 2 acts on the carrier 2 in the direction opposite to the moving direction of the carrier belt 4, so that the carrier belt 4 expands. It is considered that the carrier 2 is delayed by that amount. Further, during acceleration of the carrier motor, a force due to the acceleration is also generated in the moving direction of the carrier 2.

Therefore, the pulse cycle of the first damping pulse is calculated based on the acceleration α of the carrier 2 during the acceleration of the carrier motor and the convergence position Y of the elongation due to the friction between the shaft 3 and the carrier 2 (see FIG. 13). .

Here, when the friction coefficient between the shaft 3 and the carrier 2 is μ, the mass of the carrier 2 is m, the acceleration of the carrier 2 is α, the elastic coefficient of the carrier belt 4 is k, and the gravitational acceleration is g, the convergent position. Y is expressed as Y = (mα + μmg) / k.

First, when the time at the point E, which is the optimum position for the damping pulse supply timing, is the p-th step of the control data table 22, as shown in FIG. 13, when the damping pulse is not supplied. It is assumed that the position deviation of the carrier 2 at the p-th step is Z.
Since the convergent position during acceleration is Y, the time until returning to this position Y is the pulse cycle.

That is, when the velocity of the carrier 2 at the p-th step is v, it takes (Y−Z) / v time for the carrier 2 to return to the convergent position Y at the p-th step.
Therefore, in the pulse cycle t1 of the p-th step, (YZ) /
The time obtained by adding v becomes the pulse period td1 of the damping pulse. That is, the pulse period td1 is expressed as td1 = t1 + (Y−Z) / v.

In this way, when the calculated first damping pulse is input at the above timing, the velocity displacement of the carrier 2 becomes as shown by the dotted line graph in FIG. 8, and the positional deviation between the carrier 2 and the carrier motor 5 is shown in FIG. As shown. As shown in FIGS. 8 and 9, the vibration of the carrier 2 when the carrier motor 5 shifts from acceleration to constant speed is
Suppressed.

The supply timing of the next damping pulse is determined as follows and is preset in the time area 22a of the control data table 22.

That is, the timing of supplying the next damping pulse is set to the time of point F at which the carrier motor 5 shifts from acceleration to constant speed. The reason for setting in this way is to suppress the vibration of the carrier 2 during the constant speed of the carrier motor.

The pulse period of the next damping pulse is calculated as follows, converted into a step rate, and preset in the control data table 22.

Since the force due to the acceleration of the carrier motor 5 does not occur during the constant speed of the carrier motor, the carrier belt 4
Is considered to be due to the frictional force between the shaft 3 and the carrier 2. Therefore, the pulse cycle of the next damping pulse is calculated based on the convergence position X and the convergence position Y of the expansion of the carrier belt 4.

When the friction coefficient between the shaft 3 and the carrier 2 is μ, the mass of the carrier 2 is m, the elastic coefficient of the carrier belt 4 is k, and the gravitational acceleration is g, the convergence position X
Is expressed as X = μmg / k.

Similar to the calculation of the pulse period of the first damping pulse described above, when the time at the point F, which is the optimum position for the supply timing of the next damping pulse, is the qth step of the control data table 22, Since the convergence position during constant speed is X and the convergence position during acceleration is Y, the time until returning to the convergence position X is the pulse cycle.

That is, if the speed of the carrier 2 at the qth step is w, it takes (X−Y) / w until the carrier 2 returns to the convergent position X at the qth step. Therefore,
The time obtained by adding (X−Y) / w to the pulse period t2 at the qth step is the pulse period td2 of the damping pulse. That is, td2 = t2 + (X-Y) / w.

Thus, when the next damping pulse calculated is input at the above timing, the velocity displacement of the carrier 2 becomes as shown by the dotted line graph in FIG. 10, and the positional deviation between this carrier 2 and the carrier motor 5 is shown in FIG. As shown. As shown in FIGS. 10 and 11, the vibration of the carrier 2 at a constant speed of the carrier motor 5 is suppressed.

The CPU 11 counts the motor drive time based on the motor drive program in the ROM 12, and when the time reaches the time set in the control data table 22, the step rate corresponding to the time is read and the current is supplied. The carrier motor 5 is driven for each step based on the pulse.

In this embodiment having such a structure, when the print head 2 is driven, when the time set in the control data table 22 of the ROM 12 comes, the step rate corresponding to the time is read and the energizing pulse thereof is read. Based on the above, the drive of the carrier motor 5 is controlled for each step.

Then, for example, as shown in FIG. 10, the carrier motor 5 accelerates up to the point F, and the carrier motor 5 becomes a constant speed from the point F. The first damping pulse is supplied at point E during this acceleration. Thereby, the vibration of the carrier 2 after the point E is suppressed.

Further, at the point F where the carrier motor 5 shifts from acceleration to constant speed, the next damping pulse is supplied. As a result, the vibration of the carrier 2 during constant speed after point F is further suppressed.

In this way, at the point E where the velocity displacements of the carrier 2 and the carrier motor 5 are the closest to the final step of acceleration of the carrier motor 5 where the delay of the carrier 2 is maximum, the elongation of the carrier belt and the carrier motor are In order to supply the first damping pulse of the pulse period calculated from the convergence position Y based on the acceleration of 5, the ROM 1
Since the damping pulse is preset in the control data table 22 of No. 2, the vibration of the carrier 2 can be appropriately suppressed when the carrier motor 5 is driven, when the acceleration is changed to the constant speed, and during the constant speed. As a result, it is possible to eliminate the print disturbance immediately after the start of printing.

Further, at the point F where the carrier motor 5 shifts from the acceleration to the constant speed, the convergence position X based on the extension of the carrier belt.
And the damping pulse is preset in the control data table 22 of the ROM 12 so as to supply the damping pulse having the pulse period calculated from the convergence position Y.
Vibration of the carrier 2 at a constant speed when the carrier motor 5 is driven can be further suppressed. As a result, like the above, it is possible to eliminate the print disturbance immediately after the start of printing.

Further, the control data table 2 of the ROM 12
Since the damping pulse is preset in the step rate area 22a of No. 2, it is not necessary to secure the free running distance of the carrier 2 as in the conventional case. Therefore, the size of the device itself can be reduced.

In this embodiment, one control data table 22 has both the energization control information storage means and the vibration suppression signal information storage means, but the present invention is not limited to this. The energization control information storage means and the vibration suppression signal information storage means may be provided separately. In this case, when the CPU 11 monitors each storage means and counts the set time,
Alternatively, the control data of the step rate may be extracted from the corresponding storage means, and the carrier motor 5 may be drive-controlled based on the control data.

[0060]

As described above in detail, according to the present invention, it is possible to appropriately suppress the vibration of the carrier, eliminate the disturbance of printing immediately after the start of printing, and further reduce the size of the apparatus itself. It is possible to provide a carrier drive device capable of performing the above.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a carrier drive unit of a serial printer according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a serial printer according to the embodiment.

FIG. 3 is a measurement value calculation circuit used to calculate the pulse period of the damping pulse and the like in the embodiment.

FIG. 4 is a diagram showing a detection output of an encoder sensor supplied to the measurement value calculation circuit shown in FIG.

5 is a diagram showing drive signals for respective phases of the carrier motor supplied to the measurement value calculation circuit shown in FIG.

6 is a diagram showing a control data table set in a ROM shown in FIG.

7 is a diagram showing the relationship between motor drive elapsed time and step rate in the control data table shown in FIG.

FIG. 8 is a diagram showing the relationship between the actual speed of the carrier when the first damping pulse is supplied and the speed and time of the carrier motor when there is no load in the present embodiment.

FIG. 9 is a diagram showing the relationship between the position deviation of the carrier and the carrier motor when there is no load and the time when the first damping pulse is supplied in the present embodiment.

FIG. 10 is a diagram showing the relationship between the actual speed of a carrier when a damping pulse is supplied twice and the speed of a carrier motor when there is no load and time in the present embodiment.

FIG. 11 is a diagram showing the relationship between the position deviation of the carrier motor and the time when there is no load when the damping pulse is supplied twice in the present embodiment.

FIG. 12 is a diagram showing a relationship between an actual speed of a carrier when a damping pulse is not supplied and a speed of a carrier motor when no load is applied.

FIG. 13 is a diagram showing a relationship between a position deviation of a carrier motor when no damping pulse is supplied and a carrier motor when there is no load and time.

[Explanation of symbols]

 2 ... Carrier 4 ... Carrier belt 5 ... Carrier motor 6 ... Linear encoder sensor 6a ... Linear slit 6b ... Encoder sensor 11 ... CPU 12 ... ROM 14 ... Motor control section 21 ... Measured value calculation circuit 22 ... Control data table 22a ... Time area 22b ... Step rate area

Claims (1)

[Claims] 1. In a carrier drive device for moving a carrier capable of reciprocating in one direction via a carrier belt by a motor, when the motor is driven, the motor is energized according to the elapsed time to accelerate the motor. From the energization control information storage means for storing the energization control information for controlling from the constant speed, to measure the speed displacement of the carrier in advance, based on the speed displacement of the carrier and the speed displacement of the motor at no load, A vibration suppression signal information storage unit that stores in advance the signal cycle information of the vibration suppression signal to be supplied to the motor and the supply timing of the vibration suppression signal, which is calculated based on the positional deviation between the carrier and the motor. When the motor is driven, the energization control information is retrieved from the energization control information storage means according to the elapsed time,
When the energization control of the motor is performed based on the energization control information and the drive control from acceleration to constant speed is performed, and the elapsed time becomes the supply timing of the vibration suppression signal,
And a motor drive control means for extracting signal cycle information from the vibration suppression signal information storage means, controlling energization of the motor based on the signal cycle information, and performing vibration suppression control of the carrier. Carrier drive device.