JP2003145856A - Printer control method and printer control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer control method and a printer control device for avoiding stoppage of printing paper due to abutting of a printing paper against a paper feed roller and a driven roller during paper feeding. A printer control method and a printer control apparatus according to the present invention provide a printer control method and a printer control apparatus, wherein after a paper feed roller starts a paper feed operation, a paper feed roller and a driven roller thereof abut on the upper end of the print paper. In the speed control of the paper feeding motor until the unit is stopped while the unit is held between the paper feed roller and the driven roller, the target speed of the paper feeding motor is changed discontinuously after the start of deceleration by feedback control. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer control method and a printer control apparatus, and more particularly, to a paper feed motor for feeding a print paper to a paper feed roller and a driven roller in the paper feeding operation into the printer. The present invention relates to a printer control method and a printer control device that perform speed control. Further, the present invention relates to a recording medium recording a computer program that executes the printer control method.

[0002]

2. Description of the Related Art FIG. 12 is an explanatory view schematically showing the structure of a portion related to the feeding of printing paper and the detection of the upper and lower ends of the printing paper in a printer.

In the printer, as shown in FIG. 12, when the printing paper 50 set on the tray 90 is fed one by one by the paper feed roller 64, the upper end of the printing paper 50 is detected by the paper detection sensor 15. It A paper feed motor 63 (see FIG. 8) is connected to the paper feed roller 64, and the paper feed roller 64 is driven by drivingly controlling the paper feed motor 63, so that paper is fed into the printer.

Thereafter, the printing paper 50 is fed to the paper feed roller 65.
Then, the paper is fed by the driven roller 66, and printing is performed on the platen 84 with the ink ejected from the print head 9. When the printing progresses to the vicinity of the lower end of the printing paper 50 and the printing paper 50 is sequentially fed, the printing paper 50 does not exist on the paper detection sensor 15 at a certain point, so that the lower end of the printing paper 50 moves. To be detected.

The paper feeding operation into the printer is generally performed as described above. Among the paper feeding operations, the print paper hits the paper feed motor and the driven roller and is sandwiched.
At the time of so-called biting, it is desirable that the upper end of the printing paper is pinched in parallel with the paper feed motor and the driven roller.

However, in actuality, when the printing paper bites, the upper end of the printing paper is not completely parallel to the paper feed motor and the driven roller, but is often pinched at an angle.

Therefore, after biting the printing paper, the printing paper sandwiched by the paper feed motor and the driven roller is fed in the opposite direction and pushed back, that is, the so-called spitting is performed, and the biting and spitting are repeated several times. ,
The upper end of the printing paper is perfectly parallel to the paper feed motor and the driven roller to remove the skew of the printing paper.
The skew removal operation of the printing paper will be described in detail below with reference to the drawings.

FIG. 13 is an explanatory view schematically showing a state of the paper feed roller, the paper feed roller, and the side surface of the printing paper when the printing paper is deskewed, and FIG. FIG. 6 is an explanatory diagram schematically showing a state of the paper feed roller, the paper feed roller, and the printing paper seen from the upper surface side in the above case.

As shown in FIGS. 13A and 14A, when the printing paper 50 is fed one by one by the paper feeding roller 64, the printing paper 5 is moved in accordance with the rotation operation of the paper feeding roller 64.
The upper end of 0 gradually becomes the paper feed roller 65 and the driven roller 66.
Approaching. At this time, it is desirable that the upper end of the printing paper 50 be parallel to the paper feed roller 65 and the driven roller 66, but as shown in FIG. 14A, it may be slightly inclined.

As shown in FIGS. 13 (b) and 14 (b), when the paper feed roller 64 further rotates, the upper end of the print paper 50 abuts against the paper feed roller 65 and the driven roller 66 and is sandwiched. As described above, this is called biting of the printing paper.

In order to remove the skew of the printing paper, the paper feed roller 64 stops when it rotates by a predetermined amount. At this time, the length of the upper end portion of the printing paper protruding from the nipping position of the printing paper 50 by the paper feeding roller 65 and the driven roller 66 to the inside of the printer is referred to as a biting amount C. The biting amount C is usually set for each type of the printing paper 50, and can be changed by setting the printer according to the type of the printing paper 50. 13 (b) and 14 (b) show the case where the printing paper 50 abuts the paper feed roller 65 and the driven roller 66 at an angle.
The biting amount C indicates the biting amount in the substantially central portion of the printing paper 50.

Next, as shown in FIGS. 13C and 14C, in order to remove the skew of the printing paper 50, the paper feed roller 65 is rotated in the reverse direction while the paper feed roller 64 is stopped. Then, the printing paper 50 is fed back by the biting amount C and discharged. The printing paper 50 that is sent back by the biting amount C and discharged is in a bent state, and the upper end is pressed against the paper feed roller 65 and the driven roller 66 by the elasticity of the printing paper itself. At this time, the upper end of the printing paper 50 is substantially parallel to the paper feed roller 65 and the driven roller 66.

With the upper end of the printing paper 50 substantially parallel to the paper feed roller 65 and the driven roller 66, FIG.
As shown in FIG. 14D and FIG. 14D, the paper feed roller 6
5 is rotated in the forward direction within the range of the biting amount C, and the upper end of the printing paper 50 is bitten by the paper feed roller 65 and the driven roller 66. Then, by repeating the bite shown in FIGS. 13D and 14D and the discharge shown in FIGS. 13C and 14C several times, the upper end of the printing paper 50 is set to the paper feed roller. 65 and the driven roller 66.

When the upper end of the printing paper 50 becomes parallel to the paper feeding roller 65 and the driven roller 66, the paper feeding roller 65 is rotated in the forward direction so that the printing paper 50 is again moved to the paper feeding roller 65 and the driven roller 66. And feed roller 64 to release printing paper 50,
Then, the paper feeding operation is performed. The above is the operation of deskewing the printing paper.

Next, the speed control of the paper feeding motor from the time when the paper feeding roller starts the paper feeding operation to the time when the paper feeding roller is stopped to remove the skew of the printing paper will be described.

FIG. 15 is a first example of the waveforms of the target speed, the current speed, and the control signal of the paper feed motor from when the paper feed roller starts the paper feed operation to when the paper feed roller is stopped to remove the skew of the printing paper. It is a graph showing. In addition, FIG.
3 is a graph showing a section from the remaining distance 300 to the target stop position of 300 to 0 in the graph of FIG.

At the target stop position in FIGS. 15 and 16, the upper end of the printing paper is bitten by a predetermined biting amount C on the paper feed roller 65 and the driven roller 66, and the paper feed roller 6 is reached.
Reference numeral 4 is a position where the printing paper is stopped to remove the skew.

Remaining distance to the target stop position 800 (1 /
1440 inches (1 inch = 2.54 cm). Hereinafter, the units are omitted as appropriate. Although the PID waveform is displayed in the section from) to 700, it is not the PID control section but the acceleration control section, and the acceleration is performed toward the target speed Vref in the constant speed section from the remaining distance 700 to 300. There is.

PID control is started when a constant speed section from the remaining distance 700 to 300 is entered, and thereafter, PID control is performed until the paper feed motor is stopped so as to stop the paper feed roller 64 at the target stop position. In this section,
PID control is performed to converge overshoot and undershoot of the current speed Vcur with respect to the target speed Vref.

From the remaining distance around 300, the target speed Vref
The deceleration control is gradually started, and the deceleration control is performed more rapidly from the remaining distance 200.

By the way, an undershoot of the current speed Vcur occurs between the remaining distances 200 and 100 in the deceleration control section. This is because the upper end of the printing paper is on the paper feed roller 65 and the driven roller 66. This is because the current speed Vcur temporarily and rapidly decreased due to the collision.

Since PID control is performed in this section, a PID command value for instructing acceleration is output in order to reduce the difference between the target speed Vref and the current speed Vcur in this undershoot section.

However, while the paper feed motor is accelerated in accordance with the PID command value, the target speed Vref
In the section from the remaining distance 100 to 20, on the contrary, the overshoot of the current speed Vcur occurs.

Next, the target speed Vref and the current speed Vcur in this overshoot section are controlled by the PID control.
A PID command value for commanding deceleration is output in order to reduce the difference between and.

As a result, the overshoot of the current speed Vcur is converged at the position around the remaining distance 20, but the undershoot of the current speed Vcur occurs again in the section from the remaining distance 20 to 5.

Therefore, in order to reduce the difference between the target speed Vref and the current speed Vcur in the undershoot section, a PID command value for instructing acceleration is output, and after the current speed Vcur substantially matches the target speed Vref, the target speed Vcur A PID command value that commands deceleration according to Vref is output, the current speed Vcur becomes 0 at the target stop position, and the paper feed motor and paper feed roller stop.

[0027]

The speed control of the paper feeding motor from the time the paper feeding roller starts the paper feeding operation to the time it is stopped to remove the skew of the printing paper is as described above. The current speed Vcur generated when the upper end of the paper hits the paper feed roller 65 and the driven roller 66.
The size and length of the undershoot and overshoot vary depending on the type of printing paper and the angle between the upper end of the printing paper and the paper feed roller and driven roller.

Then, depending on the size and length of the undershoot and overshoot of the current speed Vcur, the current speed Vcur becomes 0 before the target stop position is reached and the paper feed motor and the printing paper stop. There was a problem. Hereinafter, this problem will be specifically described with reference to the drawings.

FIG. 17 shows a second example of the target speed, the current speed, and the waveform of the control signal of the paper feed motor from the start of the paper feed operation to the stop of the paper feed roller for skewing the print paper. It is a graph showing. In addition, FIG.
3 is a graph showing a section from the remaining distance 300 to the target stop position of 300 to 0 in the graph of FIG.

From the remaining distance around 300, the target speed Vref
The deceleration control is gradually started, and more rapid deceleration control is performed from the remaining distance 200. During the remaining distance 200 to 80 in the deceleration control section, the upper end of the printing paper is fed by the paper feed roller 65 and By hitting the driven roller 66, an undershoot of the current speed Vcur occurs.

Since PID control is performed in this section, a PID command value for instructing acceleration is output in order to reduce the difference between the target speed Vref and the current speed Vcur in this undershoot section.

However, while the paper feed motor is accelerated in accordance with the PID command value, the target speed Vref
In the section from the remaining distance 80 to 15, on the contrary, the overshoot of the current speed Vcur occurs.

This time, the target speed Vref and the current speed Vcur in this overshoot section are controlled by the PID control.
A PID command value for commanding deceleration is output in order to reduce the difference between and.

As a result, the overshoot of the current speed Vcur is converged at the position around the remaining distance 15, but the undershoot of the current speed Vcur occurs again in the section from the remaining distance 15 to 5.

Therefore, in order to reduce the difference between the target speed Vref and the current speed Vcur in the undershoot section, a PID command value for instructing acceleration is output and the target speed Vcur coincides with the target speed Vref at substantially the same time. At the stop position, the current speed Vcur becomes 0, and the paper feed motor and the paper feed roller stop.

The waveform of the current speed Vcur is for the case where the printing paper reaches the target stop position, but the current speed Vcur temporarily becomes almost 0 at the position of the remaining distance 10. Therefore, if the magnitude of the undershoot of the current speed Vcur in the section from the remaining distance 15 to 5 is large even slightly, the current speed Vcur becomes completely 0, and the acceleration command by the PID control cannot be made in time, and the printing paper is not printed. It stops halfway without reaching the target stop position.

Such problems may occur in the conventional paper feed motor control by the printer control method and the printer control device.

The present invention has been made in view of the above problems, and an object of the present invention is from the start of the feeding operation of the feed roller to the stop of the skew for removing the print sheet, that is, the upper end of the print sheet. In the speed control of the paper feed motor until the paper feed roller and the driven roller are clamped by the paper feed roller and the driven roller, the undershoot of the paper feed motor speed waveform is caused by the abutment of the paper feed roller and the driven roller at the upper end of the printing paper. It is an object of the present invention to provide a printer control method and a printer control device having a configuration capable of preventing a printing paper from being stopped halfway.

[0039]

According to the printer control method of the present invention, after the paper feed roller starts the paper feed operation, the paper feed roller and the driven roller have abutted the upper end of the print paper, In the speed control of the paper feed motor until the upper end of the printing paper is stopped while being sandwiched by the paper feed roller and its driven roller, the target speed of the paper feed motor is discontinuously changed after the deceleration start by the feedback control. It is characterized by

In other words, according to the printer control method of the present invention, after the paper feed roller starts the paper feeding operation, the paper feed roller and the driven roller pass the print paper top end and then the print paper top end is reached. In the speed control of the paper feed motor until it stops while holding the part between the paper feed roller and its driven roller, the present state of the paper feed motor caused by the abutment of the upper end of the printing paper with the paper feed roller and its driven roller The present invention is characterized in that the target speed is discontinuously changed to such an extent that an undershoot of the current speed with respect to the target speed of the paper feed motor is avoided when the speed is rapidly reduced.

According to the printer control device of the present invention,
After the paper feed roller starts the paper feeding operation, the paper feed roller and its driven roller come into contact with the upper end of the print paper, and then stop with the upper end of the printed paper being clamped by the paper feed roller and its driven roller. In the speed control of the sheet feeding motor up to, a target speed calculation unit for changing the target speed of the sheet feeding motor discontinuously after the deceleration start by the feedback control is provided.

In other words, according to the printer control apparatus of the present invention, after the paper feed roller starts the paper feeding operation, the paper feed roller and the driven roller pass through the upper end of the print paper and then the upper end of the print paper is reached. In the speed control of the paper feed motor until it stops while holding the part between the paper feed roller and its driven roller, the present state of the paper feed motor caused by the abutment of the upper end of the printing paper with the paper feed roller and its driven roller A target speed calculation unit that discontinuously changes the target speed to such an extent that the occurrence of undershoot of the current speed with respect to the target speed of the paper feed motor is avoided when the speed rapidly decreases. Is characterized by.

With the above configuration, the printer control method and the printer control apparatus according to the present invention make it possible to drastically reduce the target speed of the paper feed motor, and the upper end of the printing paper hits the paper feed roller and the driven roller. It is possible to avoid the occurrence of undershoot of the current speed with respect to the target speed, and it is possible to prevent output of a feedback command value that commands acceleration in the deceleration process. As a result, it is possible to prevent the subsequent overshoot and undershoot from occurring in a chain, so that the printing speed reaches the target stop position without causing a large disturbance in the current speed and the waveform of the feedback control signal. It is possible to completely avoid the situation of stopping halfway.

A computer program recording medium according to the present invention is characterized in that a computer program for executing the printer control method according to the present invention in a computer system is recorded.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION First, a schematic configuration and a control method of an ink jet printer which is a main application target of a printer control method and a printer control apparatus according to the present invention will be described.

FIG. 4 is a block diagram showing a schematic structure of the ink jet printer.

The ink jet printer shown in FIG.
A paper feed motor (hereinafter also referred to as a PF motor) 1 for feeding paper, a paper feed motor driver 2 for driving the paper feed motor 1, and a head 9 for ejecting ink onto the printing paper 50 are fixed, and the printing paper 50 is fixed. A carriage 3 that is driven in a direction parallel to the vertical direction and a direction that is perpendicular to the paper feed direction, a carriage motor (hereinafter, also referred to as a CR motor) 4 that drives the carriage 3, and a CR motor driver 5 that drives the carriage motor 4. , A DC unit 6 that delivers a DC current command value to the CR motor driver 5, and a pump motor 7 that controls the suction of ink to prevent clogging of the head 9.
And a pump motor driver 8 that drives the pump motor 7.
A head driver 10 for driving and controlling the head 9, a linear encoder 11 fixed to the carriage 3, and a linear encoder 1 having slits formed at predetermined intervals.
1 code plate 12, a rotary encoder 13 for the PF motor 1, a paper detection sensor 15 for detecting the end position of the paper being printed, and a CP for controlling the entire printer
U16, a timer IC 17 that periodically generates an interrupt signal to the CPU 16, and an interface unit (hereinafter referred to as I
Also called F. ) 19 and the host computer 18
An ASIC 20 that controls the print resolution, the drive waveform of the head 9, and the like based on the print information sent via F19.
And PROM21 and RAM22 used as work areas and program storage areas of the ASIC 20 and the CPU 16.
And the EEPROM 23, the platen 25 supporting the printing paper 50, and the printing paper 50 driven by the PF motor 1.
It is composed of a conveyance roller 27 that conveys, a pulley 30 attached to the rotation shaft of the CR motor 4, and a timing belt 31 driven by the pulley 30.

The DC unit 6 drives and controls the paper feed motor driver 2 and the CR motor driver 5 based on the control command sent from the CPU 16 and the outputs of the encoders 11 and 13. Also, the paper feed motor 1 and the CR motor 4
Are all composed of DC motors.

FIG. 5 is a perspective view showing the structure around the carriage 3 of the ink jet printer.

As shown in FIG. 5, the carriage 3 is connected to the carriage motor 4 by the timing belt 31 via the pulley 30, and is driven by the guide member 32 so as to move in parallel to the platen 25. A recording head 9 having a nozzle row that ejects black ink and a nozzle row that ejects color ink is provided on the surface of the carriage 3 that faces the printing paper, and each nozzle receives ink from the ink cartridge 34 and prints. Print characters and images by ejecting ink drops onto paper.

In the non-printing area of the carriage 3, a capping device 35 for sealing the nozzle opening of the recording head 9 during non-printing and a pump unit 36 having the pump motor 7 shown in FIG. 4 are provided. Has been. When the carriage 3 moves from the print area to the non-print area, the carriage 3 contacts a lever (not shown), the capping device 35 moves upward, and the head 9 is sealed.

When the nozzle opening row of the head 9 is clogged or the cartridge 34 is replaced, the head 9
When the ink is forcibly ejected from the nozzle, the pump unit 36 is operated with the head 9 sealed, and the negative pressure from the pump unit 36 sucks the ink from the nozzle opening row. As a result, the dust and paper dust adhering to the vicinity of the nozzle opening row are washed, and the bubbles in the head 9 are discharged to the cap 37 together with the ink.

FIG. 6 is an explanatory view schematically showing the construction of the linear encoder 11 attached to the carriage 3.

The encoder 11 shown in FIG. 6 comprises a light emitting diode 11a, a collimator lens 11b, and a detection processing section 11c. The detection processing unit 11c includes a plurality of (four) photodiodes 11d and the signal processing circuit 1
It has 1e and two comparators 11fA and 11fB.

When the voltage Vcc is applied to both ends of the light emitting diode 11a via a resistor, the light emitting diode 11a emits light. This light is condensed into parallel light by the collimator lens 11b and passes through the code plate 12. Code plate 1
The slits 2 are provided at predetermined intervals (for example, 1/180 inch (1 inch = 2.54 cm)).

The parallel light that has passed through the code plate 12 enters each photodiode 11d through a fixed slit (not shown) and is converted into an electric signal. The electric signals output from the four photodiodes 11d are processed by the signal processing circuit 11e, the signals output from the signal processing circuit 11e are compared by the comparators 11fA and 11fB, and the comparison result is output as a pulse. Pulses ENC-A, E output from the comparators 11fA, 11fB
NC-B is the output of the encoder 11.

FIG. 7 is a timing chart showing the waveforms of the two output signals of the encoder 11 when the CR motor is rotating normally and when rotating reversely.

As shown in FIGS. 7 (a) and 7 (b), the pulse ENC is used in both the forward rotation and the reverse rotation of the CR motor.
-A and pulse ENC-B differ in phase by 90 degrees. When the CR motor 4 is rotating normally, that is, when the carriage 3 is moving in the main scanning direction, FIG.
As shown in FIG. 7, the pulse ENC-A leads the pulse ENC-B by 90 degrees in phase, and when the CR motor 4 is rotating in the reverse direction, as shown in FIG.
Is configured so that the phase is delayed by 90 degrees from the pulse ENC-B. Then, one cycle T of the pulse is the slit interval of the code plate 12 (for example, 1/1
80 inches), which is equal to the time for which the carriage 3 moves in the slit interval.

On the other hand, the rotary encoder 13 for the PF motor 1 has the same structure as the linear encoder 11 except that the code plate is a rotating disk that rotates in accordance with the rotation of the PF motor 1. Two output pulses ENC-A,
Output ENC-B. In the ink jet printer, the slit spacing of the plurality of slits provided on the code plate of the rotary encoder 13 for the PF motor 1 is 1/180 inch, and when the PF motor 1 rotates by the one slit spacing, The paper is fed by 1440 inches.

FIG. 8 is a perspective view showing a portion related to paper feeding and paper detection. The position of the paper detection sensor 15 shown in FIG. 4 will be described with reference to FIG. In FIG. 8, the printing paper 50 inserted into the paper feed insertion opening 61 of the printer 60 is the paper feed roller 6 driven by the paper feed motor 63.
4 into the printer 60. Printer 6
The leading edge of the printing paper 50 fed into the 0 is detected by, for example, an optical paper detection sensor 15. Paper detection sensor 15
The paper 50 whose leading edge is detected is fed by a paper feed roller 65 and a driven roller 66 driven by the PF motor 1.

Then, ink is dropped from a recording head (not shown) fixed to the carriage 3 that moves along the carriage guide member 32 to perform printing. When the paper is fed to the predetermined position, the paper detection sensor 15 detects the end of the printing paper 50 that is currently printed. The printing paper 50 on which the printing has been completed passes through the gears 67A and 67B driven by the PF motor 1 and the gear 6
Paper discharge roller 68 and driven roller 6 driven by 7C
The sheet 9 is discharged from the sheet discharge port 62 to the outside. The rotary shaft of the paper feed roller 65 has a rotary encoder 13
Are connected.

FIG. 9 is a perspective view showing in detail the portion related to the paper feeding of the printer.

A portion of the printer portion shown in FIG. 8 related to paper feeding will be described in more detail with reference to FIGS. 8 and 9.

When the paper detection sensor 15 detects the leading edge of the printing paper 50 which is inserted from the paper feed insertion opening 61 of the printer 60 and fed into the printer 60 by the paper feed roller 64, the PF motor 1 drives the small gear 87. Smap shaft 8 which is a rotation shaft of a large gear 67a driven through
3, a paper feed roller 65 provided around the paper 3, and a driven roller 66 provided at the paper feed direction discharge side end of a holder 89 that presses the printing paper 50 fed from the paper feed side downward in the vertical direction. Thus, the printing paper 50 is fed.

The PF motor 1 is fixed to the frame 86 in the printer 60 by screws 85, the rotary encoder 13 is arranged at a predetermined position around the large gear 67a, and is the rotating shaft of the large gear 67a. Smap axis 83
A rotary encoder code plate 14 is connected to.

The printing paper 50 fed by the paper feeding roller 65 and the driven roller 66 passes on the platen 84 which supports the printing paper 50, and the small gear 87 and the large gear 67.
a, the intermediate gear 67b, the small gear 88, and the paper ejection gear 67c, the paper ejection roller 68 driven by the PF motor 1.
Then, the paper is fed by being nipped by the notched roller 69 which is a driven roller, and is discharged from the paper discharge port 62 to the outside.

While the printing paper 50 is supported on the platen 84, the carriage 3 moves left and right along the guide member 32 in the space on the platen 84, and the recording head fixed to the carriage 3 (not shown). ), Ink is ejected and printing is performed.

Next, the structure of the DC unit 6 which is a conventional DC motor control device for controlling the CR motor 4 of the above-mentioned ink jet printer and the control method by the DC unit 6 will be described.

FIG. 10 is a block diagram showing the configuration of a DC unit 6 which is a conventional DC motor control device, and FIG. 11 is a CR motor 4 controlled by the DC unit 6.
3 is a graph showing a motor current and a motor speed of the above.

The DC unit 6 shown in FIG. 10 includes a position calculating section 6a, a subtractor 6b, a target speed calculating section 6c, a speed calculating section 6d, a subtractor 6e, a proportional element 6f, and an integrating element 6g. , A differential element 6h, an adder 6i, a D / A converter 6j, a timer 6k, and an acceleration controller 6m.

The position calculator 6a detects the rising edge and the falling edge of each of the output pulses ENC-A and ENC-B of the encoder 11, counts the number of detected edges, and based on this count value. , The position of the carriage 3 is calculated. This count adds "+1" when one edge is detected when the CR motor 4 is rotating normally,
If one edge is detected when the rotation is reversed, "-
1 ”is added. The period of each of the pulses ENC-A and ENC-B is equal to the slit spacing of the code plate 12, and
The phases of the pulse ENC-A and the pulse ENC-B differ by 90 degrees. Therefore, the count value “1” of the above count corresponds to ¼ of the slit interval of the code plate 12. Thus, by multiplying the count value by 1/4 of the slit interval, the movement amount from the position of the carriage 3 corresponding to the count value "0" can be obtained. At this time, the resolution of the encoder 11 is 1 / the interval of the slits of the code plate 12.
It becomes 4. If the interval between the slits is 1/180 inch, the resolution will be 1/720 inch.

The subtractor 6b calculates the position deviation between the target position sent from the CPU 16 and the actual position of the carriage 3 obtained by the position calculation section 6a.

The target speed calculator 6c calculates the target speed of the carriage 3 based on the position deviation output from the subtractor 6b. This calculation is performed by multiplying the position deviation by the gain KP. This gain KP is determined according to the position deviation. The value of this gain KP may be stored in a table (not shown).

The speed calculator 6d is based on the output pulses ENC-A, ENC-B of the encoder 11 and the carriage 3
Calculate the speed of. This speed is obtained as follows. First, the output pulses ENC-A, E of the encoder 11
Each rising edge and falling edge of NC-B is detected, and the time interval between the edges corresponding to 1/4 of the slit interval of the code plate 12 is counted by the timer counter. If this count value is T and the slit spacing of the code plate 12 is λ, the carriage speed is λ / (4T).
Is required as. Note that, here, the speed is calculated by measuring one cycle of the output pulse ENC-A, for example, from the rising edge to the next rising edge with a timer counter.

The subtractor 6e is used for calculating the target speed and the speed calculation unit 6
The speed deviation from the actual speed of the carriage 3 calculated by d is calculated.

The proportional element 6f has a constant Gp for the speed deviation.
Is multiplied and the multiplication result is output. The integral element 6g integrates the velocity deviation multiplied by a constant Gi. Differential element 6h
Outputs a difference between the current speed deviation and the immediately preceding speed deviation by a constant Gd, and outputs the multiplication result. The encoder 11 calculates the proportional element 6f, the integral element 6g, and the derivative element 6h.
The output pulse ENC-A is performed every one cycle in synchronization with the rising edge of the output pulse ENC-A.

The outputs of the proportional element 6f, the integral element 6g and the derivative element 6h are added in the adder 6i. Then, the addition result, that is, the drive current of the CR motor 4 is sent to the D / A converter 6j and converted into an analog current. The CR motor 4 is driven by the driver 5 based on this analog voltage.

Further, the timer 6k and the acceleration control section 6m are
The PID control used for acceleration control and using the proportional element 6f, the integral element 6g, and the derivative element 6h is used for constant speed and deceleration control during acceleration.

The timer 6k generates a timer interrupt signal at predetermined time intervals based on the clock signal sent from the CPU 16.

Each time the acceleration control section 6m receives the timer interrupt signal, the acceleration control section 6m integrates a predetermined current value (for example, 20 mA) into the target current value, and the integration result, that is, the target current value of the DC motor 4 during acceleration is obtained. , D / A converter 6j. Similar to the case of PID control, the target current value is D /
The A converter 6j converts the analog current, and the driver 5 drives the CR motor 4 based on the analog current.

The driver 5 has, for example, four transistors, and turns on or off each of the above transistors based on the output of the D / A converter 6j. Mode, (b) regenerative braking operation mode (short braking operation mode, that is, a mode for maintaining the stop of the CR motor), (c) mode for stopping the CR motor,
It is configured to be able to perform.

Next, referring to FIGS. 11A and 11B, D
The operation of the C unit 6, that is, the conventional DC motor control method will be described.

When the CR motor 4 is stopped, CP
When a start command signal for starting the CR motor 4 is sent from U16 to the DC unit 6, the start initial current value I0 is sent from the acceleration controller 6m to the D / A converter 6j. This start-up initial current value I0 is the CPU and the start-up command signal.
It is sent from 16 to the acceleration control unit 6m. The current value I0 is converted into an analog voltage by the D / A converter 6j and sent to the driver 5, and the CR motor 4 starts to be activated by the driver 5 (FIGS. 11A and 11B).
reference). After receiving the start command signal, a timer interrupt signal is generated from the timer 6k every predetermined time. Each time the acceleration control unit 6m receives the timer interrupt signal, the acceleration control unit 6m integrates a predetermined current value (for example, 20 mA) into the starting initial current value I0, and sends the integrated current value to the D / A converter 6j. Then, the integrated current value is converted into an analog current by the D / A converter 6j and sent to the driver 5. Then, the CR is adjusted by the driver 5 so that the value of the current supplied to the CR motor 4 becomes the integrated current value.
The motor is driven and the speed of the CR motor 4 increases (Fig. 1
1 (b)). Therefore, the current value supplied to the CR motor 4 has a stepwise shape as shown in FIG. still,
At this time, the PID control system is also operating, but the D / A converter 6j selects and takes in the output of the acceleration control unit 6m.

The current value integration process of the acceleration control unit 6m is performed until the integrated current value reaches a constant current value Is.
When the integrated current value reaches the predetermined value Is at time t1, the acceleration control unit 6m stops the integration process and supplies the D / A converter 6j with a constant current value Is. This gives C
It is driven by the driver 5 so that the value of the current supplied to the R motor 4 becomes the current value Is (see FIG. 11 (a)).

Then, in order to prevent the speed of the CR motor 4 from overshooting, when the CR motor 4 reaches a predetermined speed V1 (see time t2), the current supplied to the CR motor 4 is reduced. The acceleration control unit 6m controls. At this time, the speed of the CR motor 4 further increases, but C
When the speed of the R motor 4 reaches a predetermined speed Vc (Fig. 11
(See time t3 in (b)), the D / A converter 6j
Select the output of the ID control system, that is, the output of the adder 6i, and select P
ID control is performed.

That is, the target speed is calculated on the basis of the positional deviation between the target position and the actual position obtained from the output of the encoder 11, and the speed between this target velocity and the actual speed obtained from the output of the encoder 11 is calculated. The proportional element 6f, the integral element 6g, and the differential element 6h operate based on the deviation, proportional, integral, and differential operations are performed, respectively, and the CR motor 4 is controlled based on the sum of these operation results. .
The proportional, integral, and derivative operations are performed in synchronization with the rising edge of the output pulse ENC-A of the encoder 11, for example. As a result, the speed of the DC motor 4 is controlled to the desired speed Ve. The predetermined speed Vc
Is preferably 70 to 80% of the desired speed Ve.

From time t4, the DC motor 4 reaches the desired speed, and the carriage 3 also reaches the desired constant speed Ve, and the printing process can be performed.

When the printing process is completed and the carriage 3 approaches the target position (see time t5 in FIG. 11B), the position deviation becomes smaller and the target speed also becomes smaller. Therefore, the speed deviation, that is, the subtracter 6e. Output becomes negative, the DC motor 4 is decelerated, and stops at time t6.

Although the content of the drive control when the DC motor is the CR motor 4 has been described above, the content of the drive control is also the case when the DC motor is the paper feed motor (PF motor) 1 or the paper feed motor. It will be almost the same.

An embodiment of a printer control method and a printer control apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a graph showing the target speed and the actual motor speed of the paper feed motor controlled by the printer control method and the printer control apparatus according to the present invention, and the waveform of each control signal.

In the printer control method and the printer control apparatus according to the present invention, from the start of the paper feed operation to the stop of the paper feed skew, that is, to the paper feed roller and its driven roller. In the speed control of the paper feed motor until the upper end of the printing paper is stopped by sandwiching the upper end of the printing paper with the paper feed roller and its driven roller after passing through the upper end of the printing paper, the target speed at the start of deceleration becomes discontinuous. It is characterized in that it is changed.

In the conventional printer control method and printer control apparatus, in the speed control of the paper feed motor from when the paper feed roller starts the paper feed operation to when the paper feed roller is stopped to remove the skew of the printing paper, after the PID control is started. The target speed of was supposed to be continuously changed. Therefore, when the current speed Vcur temporarily and rapidly decreases due to the upper end of the printing paper hitting the paper feed roller 65 and the driven roller 66, an undershoot of the current speed Vcur almost certainly occurs. Conversely, if an attempt is made to compensate for this undershoot by PID control, then an overshoot will occur, and if an attempt is made to compensate for this overshoot by PID control, an undershoot will occur again and printing paper will stop halfway. It invites the situation.

Therefore, in order to prevent the problem that the printing paper is stopped halfway, the paper feed roller 65 at the upper end of the printing paper is used.
And the current speed Vcu due to the collision with the driven roller 66
It is necessary to avoid the undershoot of r. If the target speed after the PID control is started is continuously changed like the conventional printer control method and printer control device, it is extremely difficult to avoid the undershoot.

Therefore, in the printer control method and the printer control apparatus according to the present invention, the target speed at the start of deceleration under the PID control which is the feedback control is discontinuously changed.

With reference to the graph of FIG. 1, the speed control of the paper feed motor by the printer control method and printer control device according to the present invention will be described in detail.

The target stop position in FIG. 1 is a position where the upper end of the printing paper is bitten by a predetermined biting amount C on the paper feeding roller 65 and the driven roller 66, and the paper feeding roller 64 is stopped to remove the skew of the printing paper. Is.

Remaining distance to the target stop position 800 (1 /
1440 inches (1 inch = 2.54 cm). Hereinafter, the units are omitted as appropriate. Although the PID waveform is displayed in the section from) to 700, it is not the PID control section but the acceleration control section, and the acceleration is performed toward the target speed Vref in the constant speed section from the remaining distance 700 to 300. There is.

When the constant speed section from the remaining distance 700 to 200 is entered, the PID control is started, and thereafter, the PID control is performed until the paper feed motor is stopped in order to stop the paper feed roller 64 at the target stop position. In this section,
PID control is performed to converge overshoot and undershoot of the current speed Vcur with respect to the target speed Vref.

Then, the deceleration control is started from the remaining distance 200. However, in the printer control method and the printer control apparatus according to the present invention, as shown in FIG. 1, the deceleration start is performed under the PID control. At this time, the target speed Vref is discontinuously changed.

As described above, by changing the target speed Vref discontinuously, the target speed Vref can be drastically reduced, and the upper end of the printing paper is fed by the paper feed roller 65.
And the current speed V caused by hitting the driven roller 66
It is possible to avoid the occurrence of undershoot with respect to the cur target speed Vref. That is, even if the current speed Vcur is temporarily and suddenly decreased due to the abutting of the printing paper, if the target speed Vref is further decreased, the temporarily decreased portion of the current speed Vcur is below the target speed Vref. It doesn't shoot. If the undershoot does not occur, the PID command value for commanding acceleration is not output.

As a result, it is possible to prevent the subsequent occurrence of overshoots and undershoots. Therefore, as shown in FIG. 1, a large disturbance may occur in the current speed Vcur and the waveform of the PID control signal. It is also possible to completely avoid the situation where the printing paper stops halfway before reaching the target stop position.

The size of the undershoot of the current speed Vcur caused by the abutting of the printing paper changes depending on the type of the printing paper, the angle between the upper end of the printing paper and the paper feed roller and the driven roller, and the like. Normally, the thicker the printing paper, the larger the size of the undershoot of the current speed Vcur, and the closer the upper end of the printing paper and the paper feed roller and the driven roller are to each other, the smaller the size of the undershoot of the current speed Vcur. growing. Also, the larger the width of the printing paper, the larger the size of the undershoot of the current speed Vcur, and the printing paper thicker than the setting of the thickness of the printing paper is used, or two or more printing papers are erroneously fed. In the case where the current speed Vcur is generated, the magnitude of the undershoot of the current speed Vcur is increased.

Therefore, when changing the target speed Vref discontinuously, various conditions are taken into consideration regarding how much the target speed Vref is reduced, and the target speed Vref is set to an extent that can deal with the maximum undershoot that can occur. It is recommended to reduce it discontinuously. For example, the value of the target speed Vref may be instantly reduced at the same time as the start of deceleration by about 10% of the value of the target speed Vref immediately before the start of deceleration.

If the bite amount C of the printing paper at the target stop position where the paper feed roller 64 is stopped to remove the skew of the printing paper is set to a large value, that is, the printing paper strikes before deceleration starts. When such settings are made, the effect obtained by applying the configuration of the printer control method and the printer control device according to the present invention is not so great.

In the printer control method and the printer control apparatus according to the present invention, when the setting is such that the abutting of the printing paper occurs after the start of deceleration under the PID control as in the present embodiment, A greater effect can be obtained.

The printer control apparatus according to the present invention is provided with the target speed calculation unit 6c for changing the target speed Vref discontinuously as described above. The overall configuration of the printer control device according to the present invention is the same as that of the motor control device shown in FIG.

The printer control device according to the present invention can be constituted by the CPU 16 in FIG. 4, for example. In that case, the program for operating the CPU 16 is
In addition to the recording medium described below, for example, P in FIG.
It can be recorded and held in the ROM 21 and the EEPROM 23.

In the above description, the target speed Vref
Although the timing of discontinuously changing is described as the start of deceleration under PID control, specifically, it may be the same as the start of deceleration, or at a predetermined timing after the start of deceleration. It may be present or may be set at any timing after the start of deceleration. In short, the timing may be such that the current speed Vcur does not cause an undershoot with respect to the target speed Vref when the current speed Vcur temporarily and rapidly decreases due to the collision of the printing paper.

As the feedback control, P control and PI control can be adopted in addition to PID control.

FIG. 2 is an explanatory diagram showing an external configuration of a recording medium recording a computer program for executing the printer control method according to the present invention and a computer system using the recording medium, and FIG. 3 is a block diagram showing the configuration of the computer system shown in FIG.

The computer system 70 shown in FIG.
Is a computer main body 71 housed in a mini tower type housing and a display device 72 such as a CRT (Cathode Ray Tube), a plasma display, and a liquid crystal display device.
And a printer 73 as a recording / output device, a keyboard 74a and a mouse 74b as input devices, a flexible disk drive device 76, and a CD-ROM drive device 77. FIG. 3 is a block diagram showing the configuration of the computer system 70. In a housing in which a computer main body 71 is housed, an internal memory 75 such as a RAM (Random Access Memory) and a hard disk drive unit 78 are shown. External memory is further provided. A recording medium in which a computer program for executing the printer control method according to the present invention is recorded is used in this computer system 70. As the recording medium, for example, a flexible disk 81 and a CD-ROM (Read Only Memory) 82 are used, but in addition, an MO (Magneto Optical) disk, a DVD (Digital Versatile Disk), other optical recording disks, a card memory Alternatively, a magnetic tape or the like may be used.

[0113]

According to the printer control method and the printer control apparatus of the present invention, after the paper feed roller starts the paper feed operation, the paper feed roller and the driven roller pass through the upper end of the print paper. In the speed control of the paper feed motor until the upper end of the printing paper is stopped while being sandwiched by the paper feed roller and its driven roller, the target speed of the paper feed motor is discontinuously changed after the deceleration start by the feedback control. As a result, the target speed of the paper feed motor is drastically reduced, and it is possible to avoid the occurrence of undershoot of the target speed of the current speed due to the top edge of the printing paper hitting the paper feed roller and the driven roller. It is possible to prevent the output of the feedback command value that commands the acceleration in the process. As a result, it is possible to prevent the subsequent overshoot and undershoot from occurring in a chain, so that the printing speed reaches the target stop position without causing a large disturbance in the current speed and the waveform of the feedback control signal. It is possible to completely avoid the situation of stopping halfway.

According to the computer program recording medium of the present invention, a computer program for executing any one of the printer controlling methods of the present invention in a computer system is recorded, and thus the printer controlling method of the present invention. By executing any of the above in a computer system, the same effect as described above can be obtained.

[Brief description of drawings]

FIG. 1 is a graph showing a target speed and an actual motor speed of a sheet feeding motor controlled by a printer control method and a printer control apparatus according to the present invention, and waveforms of respective control signals.

FIG. 2 is an explanatory diagram showing an external configuration of a recording medium in which a program for executing the printer control method according to the present invention is recorded and a computer system in which the recording medium is used.

FIG. 3 is a block diagram showing the configuration of the computer system shown in FIG.

FIG. 4 is a block diagram showing a schematic configuration of an inkjet printer.

FIG. 5 is a perspective view showing a configuration around a carriage 3 of the inkjet printer.

FIG. 6 is an explanatory view schematically showing a configuration of a linear encoder 11 attached to a carriage 3.

FIG. 7 is a timing chart showing waveforms of two output signals of the encoder 11 during forward rotation and reverse rotation of the CR motor.

FIG. 8 is a perspective view showing a part related to paper feeding and paper detection.

FIG. 9 is a perspective view showing in detail a portion related to paper feeding of the printer.

FIG. 10 is a block diagram showing the configuration of a DC unit 6 that is a DC motor control device.

FIG. 11 is a graph showing a motor current and a motor speed of a DC motor motor 4 controlled by a DC unit 6.

FIG. 12 is an explanatory diagram that schematically shows the configuration of a part related to the feeding of printing paper and the detection of the upper and lower ends of the printing paper in the printer.

FIG. 13 is an explanatory diagram that schematically shows a state of the paper feed roller, the paper feed roller, and the side surface of the print paper when the print paper is skewed.

FIG. 14 is an explanatory diagram schematically showing a state of the paper feed roller, the paper feed roller, and the top surface side of the printing paper when the printing paper is skewed.

FIG. 15 shows a first example of the target speed, the current speed, and the waveform of the control signal of the paper feed motor from when the paper feed roller starts the paper feed operation to when the paper feed roller stops due to deskewing of the printing paper. Graph.

16 is a graph enlarging only the horizontal axis of the section from the remaining distance 300 to 0 to the target stop position in the graph of FIG.

FIG. 17 shows a second example of the target speed, the current speed, and the waveform of the control signal of the paper feed motor from when the paper feed roller starts the paper feed operation to when the paper feed roller is stopped to remove the skew of the printing paper. Graph.

FIG. 18 is a graph showing a section from the remaining distance 300 to 0 to the target stop position in the graph of FIG.

[Explanation of symbols]

1 Paper feed motor (PF motor) 2 Paper feed driver 3 carriage 4 Carriage motor (CR motor) 5 Carriage motor driver (CR motor driver) 6 DC unit 6a Position calculation unit 6b subtractor 6c Target speed calculation means 6d Speed calculator 6e Subtractor 6f proportional element 6g integral element 6h differential element 6j D / A converter 7 pump motor 8 Pump motor driver 9 recording head 10 head driver 11 Linear encoder 12 code plate 13 Encoder (rotary encoder) 14 Code plate for rotary encoder 15 Paper detection sensor 16 CPU 17 Timer IC 18 Host computer 19 Interface section 20 ASIC 21 PROM 22 RAM 23 EEPROM 25 platen 30 pulley 31 Timing Belt 32 Carriage motor guide member 34 ink cartridges 35 capping device 36 pump units 37 cap 50 recording paper 60 printer 61 Paper feed insertion slot 62 paper exit 64 paper feed rollers 65 Paper feed roller 66 driven roller 67a large gear 67b Intermediate gear 67c Paper ejection gear 68 Paper ejection roller 69 Driven roller (Giza roller) 83 Smap axis 84 Platen 87 small gear 88 small gears 89 holder 90 trays

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C058 GA07 GA09 GB07 GB19 GB30                       GB43 GB47 GB53 GC01 GE04                       GE08 GE10 GE16                 3F102 AA11 AB01 BA02 BB02 CA00                       CB01 CB02 DA08 EA01 EC02                       FA07                 3F343 FA02 FB04 FC11 FC27 GA02                       GB01 GC01 GD01 HB03 JA01                       KB04 LC09 LD10 MA03 MA09                       MA41 MA42 MB04 MB09 MC09

Claims (5)

[Claims] 1. A paper feed roller starts a paper feed operation, and after the upper end of the print paper hits the paper feed roller and its driven roller, the upper end of the print paper is clamped by the paper feed roller and its driven roller. In the speed control of the paper feed motor until it stops in this state, the target speed of the paper feed motor is discontinuously changed after the deceleration start by the feedback control. 2. The paper feed roller starts the paper feed operation, and after the paper feed roller and its driven roller hit the top edge of the print paper, the upper end of the printed paper is clamped by the paper feed roller and its driven roller. In the speed control of the paper feed motor until it stops in the state where the paper feed motor and the driven roller rapidly collide with the current speed of the paper feed motor due to the abutment of the upper end of the print paper, A printer control method, wherein the target speed is discontinuously changed to such an extent that an undershoot of the current speed with respect to the target speed of the motor is avoided. 3. A computer program recording medium on which a computer program for executing the printer control method according to claim 1 or 2 in a computer system is recorded. 4. An upper end portion of the printing paper is held between the paper feeding roller and its driven roller after the paper feeding roller starts a paper feeding operation and after the upper end of the printing paper hits the paper feeding roller and its driven roller. In the speed control of the paper feed motor until it stops in this state, the printer control is provided with a target speed calculation unit for changing the target speed of the paper feed motor discontinuously after the deceleration start by the feedback control. apparatus. 5. An upper end portion of the printing paper is held between the paper feeding roller and its driven roller after the paper feeding roller starts a paper feeding operation and after the upper end of the printing paper hits the paper feeding roller and its driven roller. In the speed control of the paper feed motor until it stops in the state where the paper feed motor and the driven roller rapidly hit the upper end of the print paper, the current speed of the paper feed motor rapidly decreases A printer control device comprising: a target speed calculation unit that discontinuously changes the target speed to the extent that an undershoot of the current speed with respect to the target speed of the motor is avoided.