JP2001186785A - Device and method for controlling motor and/or storage medium with recorded control program of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect speed even if backward rotation occurs at the mounting part of an encoder when a motor is activated. SOLUTION: An inversion detection part 6q, a first pulse counter 6r, and a speed operation part 6d are provided. The backward rotation detection part 6q detects whether backward rotation occurs at a mounting part 65 of an encoder when a motor is activated or not based on the output pulse of an encoder 13 rotating according to the rotation of a motor 1. The first pulse counter 6r counts the edge of the output pulse of the encoder after the rotation of the mounting part of the encoder is changed from backward rotation to forward one, and outputs a start command when the count value reaches a first specific value. The speed operation part 6d calculates the speed of the motor based on the output pulse of the encoder if a start command is received when the backward rotation occurs at the mounting part of the encoder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device and a control method for a motor, and a recording medium on which a control program for a motor is recorded.

[0002]

2. Description of the Related Art A conventional motor control device is shown in FIGS.
0 will be described. The motor control device is used in an ink jet printer, and the schematic configuration of the ink jet printer is shown in FIG.

This ink jet printer includes a paper feed motor (hereinafter also referred to as a PF motor) 1 for feeding paper,
A paper feed motor driver 2 for driving this paper feed motor 1
, A carriage 3, a carriage motor (hereinafter also referred to as a CR motor) 4 for driving the carriage 3, and a CR motor driver 5 for driving the carriage motor 4
A DC unit 6, a pump motor 7 for controlling suction of ink for preventing clogging, a pump motor driver 8 for driving the pump motor 7, and ink ejected to the printing paper 50 fixed to the carriage 3. Head 9
And a head driver 10 for driving and controlling the head 9
And a linear encoder 11 fixed to the carriage 3
And a code plate 12 having slits formed at predetermined intervals,
A rotary encoder 13 for the PF motor 1 and a paper detection sensor 15 for detecting the end position of the paper being printed
A CPU 16 for controlling the entire printer;
Timer IC1 that periodically generates an interrupt signal for
7, an interface unit (hereinafter, also referred to as IF) 19 for transmitting and receiving data to and from the host computer 18,
An ASIC 20 for controlling the printing resolution and the driving waveform of the head 9 based on the printing information sent from the host computer 18 via the IF 19;
PROM 21, RAM 22, and EEPROM 23 used as a work area and a program storage area of PU 16
A platen 25 supporting the paper 50 being printed, a transport roller 27 driven by the PF motor 1 to transport the print paper 50, a pulley 30 attached to the rotation shaft of the CR motor 4, and the pulley 30. And a driven timing belt 31.

The DC unit 6 drives and controls the paper feed motor driver 2 and the CR motor driver 5 based on control commands sent from the CPU 16 and outputs of the encoders 11 and 13. Further, the paper feed motors 1 and C
Each of the R motors 4 is constituted by a DC motor.

FIG. 5 shows a configuration around the carriage 3 of the ink jet printer.

The carriage 3 is connected to the carriage motor 4 via a pulley 30 by a timing belt 31, and is driven by a guide member 32 to move in parallel with the platen 25. On the surface of the carriage 3 facing the printing paper, a recording head 9 composed of a nozzle row for discharging black ink and a nozzle row for discharging color ink is provided. Each nozzle row is supplied with ink from an ink cartridge 34. Prints characters and images by ejecting ink droplets on printing 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. I have. When the carriage 3 moves from the print area to the non-print area, the capping device 35 moves upward by contacting a lever (not shown) to seal the head 9.

When clogging occurs in the nozzle opening row of the head 9 or when the cartridge 34 is replaced or the like,
When the ink is forcibly ejected from the pump unit, the pump unit is operated while the head 9 is sealed, and the ink is sucked out from the nozzle opening row by the negative pressure from the pump unit. As a result, dust and paper dust adhering in the vicinity of the nozzle opening row are washed, and the air bubbles in the head 9 are discharged to the cap 37 together with the ink.

Next, the configuration of the linear encoder 11 attached to the carriage 3 is shown in FIG. The encoder 11 includes a light emitting diode 11a and a collimator lens 11
b and a detection processing unit 11c. The detection processing unit 11c includes a plurality (four) of photodiodes 11d,
A signal processing circuit 11e and two comparators 11f _A ,
It has a 11f _B, and.

When a voltage Vcc is applied to both ends of the light emitting diode 11a via a resistor, light is emitted from the light emitting diode 11a. This light is made parallel by the collimator lens 11b and passes through the code plate 12. Code plate 12
At a predetermined interval (for example, 1/180 inch (= 1/18)
(0.254 cm)).

The parallel light that has passed through the code plate 12 passes through a fixed slit (not shown) to each photodiode 11d.
And is converted into an electric signal. The electric signals output from the four photodiodes 11d are applied to the signal processing circuit 11
The signal is processed in e. The signals outputted from the signal processing circuit 11e is a comparator 11f _A, are compared in 11f _B, the compared results are outputted as pulses. Pulse E output from comparators 11f _A and 11f _B
NC-A and ENC-B are outputs of the encoder 11.

The phases of the pulses ENC-A and ENC-B differ by 90 degrees. When the CR motor 4 is rotating forward, that is, when the carriage 3 is moving in the main scanning direction, the pulse ENC-A is changed to the pulse ENC as shown in FIG.
When the CR motor 4 is rotating in the reverse direction by 90 degrees from that of the pulse ENC-B as shown in FIG.
The encoder 4 is configured such that the phase of A is delayed by 90 degrees from the pulse ENC-B. One cycle T of the pulse is equal to the slit interval of the code plate 12 (for example, 1 /
180 inches (= 1/180 × 2.54 cm), which is equal to the time during which the carriage 3 moves through the slit interval.

On the other hand, the rotary encoder 13 for the PF motor 1 has the same configuration 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. Output pulses ENC-A,
Outputs ENC-B. In the ink jet printer, the slit interval of a plurality of slits provided on the code plate of the encoder 13 for the PF motor 1 is 1 /.
180 inches (= 1/180 × 2.54 cm)
When the F motor 1 rotates by one slit interval, 1 /
The paper is fed by 1440 inches (= 1440 × 2.54 cm).

Next, the paper detection sensor 15 shown in FIG.
Will be described with reference to FIG. In FIG. 8, the paper 50 inserted into the paper feed slot 61 of the printer 60 is shown.
Is a paper feed roller 64 driven by a paper feed motor 63
Is sent into the printer 60. Printer 60
The leading end of the paper 50 fed into the inside is detected by, for example, an optical paper detection sensor 15. This paper detection sensor 15
The paper 50 whose leading end is detected is fed by a paper feed roller 65 driven by the PF motor 1 and a driven roller 66.

Subsequently, printing is performed by dropping ink from a recording head (not shown) fixed to the carriage 3 that moves along the carriage guide member 32. When the paper is fed to a predetermined position,
The end of the printed paper 50 is detected by the paper detection sensor 15. The gear 67c driven by the PF motor 1 drives the gear 67c via the gear 67b, whereby the paper discharge roller 68 and the driven roller 69 are driven to rotate, and the paper 50 on which printing has been completed is discharged to the paper discharge port. It is discharged from 62 to the outside.

A code plate of the encoder 13 is attached to a rotation shaft of the paper feed roller 65.

Next, control of the PF motor 1 of the conventional ink jet printer will be described with reference to FIGS. The control of the PF motor 1 is performed by a DC unit 6, which includes a position counter 6a, a subtraction unit 6b, a target speed calculation unit 6c, a speed calculation unit 6d, and a subtractor as shown in FIG. 6e, a proportional element 6f, an integral element 6g, a differential element 6h, and an adder 6i.
, A D / A converter 6j, a timer 6k, and an acceleration control unit 6m.

The position counter 6a detects the rising edge and the falling edge of each of the output pulses ENC-A and ENC-B of the encoder 13, counts the number of detected edges, and based on the count value, determines the PF. The amount of paper fed by the motor 1 is calculated. When the PF motor 1 is rotating forward, "+1" is added when one edge is detected, and when the PF motor 1 is rotating reversely, "-1" is added when one edge is detected. Is added. Pulse ENC-
Each period of A and ENC-B is equal to the slit interval of the code plate, and pulse ENC-A and pulse ENC-B
Are 90 degrees out of phase. Therefore, the count value “1” of the above-described count corresponds to １ ／ of the slit interval of the code plate of the encoder 13. When the PF motor 1 rotates by one slit interval, 1/1440 inch (= 1
/1440×2.54 cm), so that the count value of the position counter 6a becomes 1/4 × 1/14
By multiplying by 40 inches (= 1 / 4.times.1 / 1440.times.2.54 cm), the paper feed amount from the position corresponding to the count value "0" of the PF motor 1, that is, the start position, can be obtained. . At this time, the resolution of the encoder 13 is 1/5.
It is 760 inches (= 1/5760 × 2.54 cm).

The subtractor 6b calculates a positional deviation between the target position and the count value of the position counter 6a.

The target speed calculator 6c calculates a target speed of the PF motor 1 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 the gain Kp may be stored in a table (not shown).

The speed calculator 6d calculates the speed of the PF motor 1 based on the output pulses ENC-A and ENC-B of the encoder 13. This speed is determined as follows. First, the output pulses ENC-A, EN of the encoder 13
The rising edge and the falling edge of each of CB are detected, and the time interval between the edges is counted by a timer counter. If this count value is T, the speed is 1
/ T is proportional to / T.

The subtractor 6e has a target speed and a speed calculator 6
A speed deviation from the actual speed of the PF motor 1 calculated by d is calculated.

The proportional element 6f multiplies the speed deviation by a constant Gp and outputs the result of the multiplication. The integral element 6g integrates the value obtained by multiplying the speed deviation by a constant Gi. The differential element 6h multiplies the difference between the current speed deviation and the immediately preceding speed deviation by a constant Gd, and outputs the multiplication result. The calculation of the proportional element 6f, the integral element 6g, and the differential element 6h is performed by the encoder 13
Is performed in synchronization with, for example, the rising edge of the output pulse ENC-A.

The outputs of the proportional element 6f, the integral element 6g, and the differential element 6h are added in an adder 6i. Then, the addition result, that is, the drive current of the PF motor 1 is D / A
The signal is sent to the converter 6j and converted into an analog current.
PF is determined by the driver 10 based on the analog current.
The motor 1 is driven.

The timer 6k and the acceleration control section 6m are used for acceleration control, and the PID control using the proportional element 6f, the integral element 6g, and the differential 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 a clock signal sent from the CPU 16.

The acceleration control unit 6m integrates a predetermined current value (for example, 20 mA) to the target current value every time the timer interrupt signal is received, and the integration result, that is, the target current value of the PF motor 1 during acceleration is D / D. It is sent to the A converter 6j.
As in the case of the PID control, the target current value is converted to an analog current by the D / A converter 6j, and based on the analog current, the PF motor 1
Is driven.

The driver 10 includes, for example, four transistors, and turns on or off each of the transistors based on the output of the D / A converter 6j. (A) Operation for rotating the PF motor 1 forward or backward Mode (b) Regenerative brake operation mode (short brake operation mode, that is, a mode in which the PF motor 1 is kept stopped) (c) A configuration in which a mode in which the PF motor 1 is stopped can be performed. .

Next, referring to FIGS. 11A and 11B, DC
The operation of the unit 6 will be described. When the activation command signal for starting the PF motor 1 is transmitted, it launched from the acceleration controller 6m initial current value I ₀ is fed to the D / A converter 6j from CPU16 in the DC unit 6 when the PF motor 1 is stopped . The starting initial current value I ₀ is sent from the CPU 16 to the acceleration control unit 6m together with the starting command signal. The current value I ₀ is converted into an analog current by the D / A converter 6j and sent to the driver 10,
The driver 10 starts the PF motor 1 (see FIGS. 10A and 10B).

After receiving the start command signal, the timer 6k generates a timer interrupt signal at predetermined time intervals. Acceleration controller 6m each time receiving a timer interrupt signal, starts a predetermined current value to an initial current value I ₀ by integrating (e.g. 20 mA), 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 10.
Then, the driver 5 drives the PF motor 1 so that the value of the current supplied to the PF motor 1 becomes the integrated current value, and the speed of the PF motor 1 increases (FIG. 10).
(B)). Therefore, the current value supplied to the PF motor 1 has a step shape as shown in FIG.

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 accumulation process of the current value of the acceleration controller 6m is carried out until the integrated current value becomes a constant current value I _S.
When the current value obtained by integrating at time t ₁ becomes the predetermined value I _S,
The acceleration control unit 6m stops the integration process and supplies a constant current value I _S to the D / A converter 6j. Thus, the PF motor 1 is driven by the driver 10 so that the value of the current supplied to the PF motor 1 becomes the current value I _S (see FIG. 10A).

In order to prevent the speed of the PF motor 1 from overshooting, when the PF motor 1 reaches a predetermined speed V ₁ (time t ₂ ), the PF motor 1
Is controlled by the acceleration control unit 6m so as to reduce the current supplied to. In this case although the speed is further increased PF motor 1, (see time _{t 3} in FIG. 10 (b)) and the speed of the PF motor 1 reaches a predetermined speed v _c, D / A converter 6
j selects the output of the PID control system, that is, the output of the adder 6i, and the PID control is performed.

That is, the target speed is calculated based on the positional deviation between the target position and the count value of the counter 6a.
Based on the speed deviation between the target speed and the actual speed obtained from the output of the encoder 13, the proportional element 6f, the integral element 6g, and the differential element 6h operate, and perform proportional, integral, and differential operations, respectively. The control of the PF motor 1 is performed based on the sum of these calculation results. Note that the above-described proportional, integral, and differential operations are performed by, for example, the encoder 13.
In synchronization with the rising edge of the output pulse ENC-A. As a result, the speed of the PF motor 1 is controlled to a desired speed v _e . Incidentally, it is preferable that the predetermined speed v _c 70 to 80% of the value of desired speed v _e.

From time t ₄ , the PF motor 1 starts operating at the desired speed v _e.
Becomes Thereafter, the PF motor 1 approaches the target position (see time t ₅ in FIG. 10 (b)), deceleration of the PF motor 1 is carried out, the PF motor 1 is stopped at time t _6.

[0036]

In the ink jet printer thus configured, the paper feed is performed by the paper feed roller 65 driven by the PF motor 1 and the driven roller 66 as described with reference to FIG. The driven roller 66 is configured to press the paper 50 against the paper feed roller 65 by a spring 80 as shown in FIG.

However, when the PF motor 1 is started, the paper 50 is moved by the spring 80 in a direction opposite to the normal feeding direction. As a result, the paper feed roller 65 rotates in the reverse direction, that is, the encoder 13 attached to the paper feed roller 65 rotates in the reverse direction. When the mounting unit 65 to which the encoder 13 is mounted rotates reversely when the PF motor 1 is started, the output of the speed calculation unit 6d that calculates the speed based on the output of the encoder 13 becomes inaccurate, or the speed calculation unit 6d A problem arises that the timer counter used for the speed calculation overflows and an accurate speed cannot be detected.

The present invention has been made in view of the above circumstances, and provides a motor control device that can accurately detect a speed at the time of starting the motor even if reverse rotation occurs in a mounting portion on which an encoder is mounted. It is another object of the present invention to provide a recording medium storing a control program for a motor and a control program for a motor.

[0039]

According to the motor control apparatus of the present invention, when the motor is started, reverse rotation of the mounting portion to which the encoder is mounted occurs based on the output pulse of the encoder that rotates according to the rotation of the motor. A reverse rotation detection unit for detecting whether or not the rotation of the mounting unit has changed from a reverse rotation to a normal rotation when a reverse rotation has occurred in the mounting unit. A first pulse counter that outputs a start command when the value reaches a first predetermined value; and a reverse rotation occurs in the mounting portion. A speed calculating unit for calculating the speed of the motor based on the speed.

Note that the edge of the output pulse of the encoder is counted when the motor is started, and a start command is output when the count value reaches a second predetermined value.
The speed calculation unit further includes a pulse counter based on a start command output from the first pulse counter when the attachment unit reversely rotates. The speed calculation may be started based on a start command output from the second pulse counter.

The motor may be configured to be a paper feed motor of a printing apparatus.

[0042] It should be noted that a speed controller for controlling the speed of the motor based on a deviation between the target speed of the motor and the speed of the motor calculated by the speed calculator may be provided.

Further, the motor control method according to the present invention
Based on an output pulse of an encoder that rotates according to the rotation of the motor, detecting whether or not a reverse rotation has occurred in a mounting portion to which the encoder is mounted when the motor is started, and when a reverse rotation occurs in the mounting portion. ,
Counting the edges of the output pulse of the encoder after the rotation of the mounting portion has changed from reverse rotation to normal rotation, and outputting a start command when the count value reaches a first predetermined value; Calculating a speed of the motor based on an output pulse of the encoder when receiving a command.

Before the step of calculating the speed of the motor, the edge of the output pulse of the encoder is counted, and when the count value becomes a second predetermined value or the mounting portion does not rotate in the reverse direction. May be configured to include a step of outputting a start command to the server.

It should be noted that, after the step of calculating the speed of the motor, a step of controlling the speed of the motor based on a deviation between the target speed of the motor and the calculated speed is provided. May be.

The motor may be a paper feed motor of a printing apparatus.

In the recording medium storing the motor control program according to the present invention, when the motor is started, reverse rotation occurs in the mounting portion to which the encoder is mounted, based on the output pulse of the encoder that rotates in accordance with the rotation of the motor. And a step of detecting whether or not the rotation of the mounting portion, when reverse rotation occurs, counts the edge of the output pulse of the encoder after the rotation of the mounting portion changed from reverse rotation to normal rotation, the count value is A step of outputting a start command when the first predetermined value is reached, and a step of calculating a speed of the motor based on an output pulse of the encoder when receiving the start command. And

[0048]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a motor control device according to the present invention will be described with reference to FIGS. FIG. 1 shows the configuration of the motor control device according to this embodiment, and its operation is shown in the flowchart of FIG. The motor control device of this embodiment is different from the conventional motor control device (DC unit) 6 shown in FIG.
p, 6r, a reverse rotation detector 6q, an AND gate 6s,
An OR gate 6t is newly added.
The components other than the pulse counters 6p and 6r, the reverse rotation detector 6q, the AND gate 6s, and the OR gate 6t have already been described with reference to FIG.

Next, the configuration and operation of this embodiment will be described with reference to FIG.
This will be described with reference to FIGS.

Now, consider a case where a start command signal is given to the control device 6 and the PF motor 1 starts to be started. When the PF motor 1 starts, the output pulse EN from the encoder 13 is output.
CA and ENC-B are output. Then, the number of rising edges and falling edges of output pulses ENC-A and ENC-B is counted by pulse counter 6p. Then, the count value becomes a predetermined value N ₁ (for example, N _1
1 = 7), the command signal from the pulse counter 6p becomes A
The signal is output to the ND gate 6s (see step F1 in FIG. 2). At this time, it is determined whether or not the mounting portion (paper feed roller 65) on which the encoder 13 is mounted has rotated in the reverse direction.
It is detected by the reverse rotation detecting unit 6q based on the output of the encoder 13 (see step F2 in FIG. 2). If the reverse rotation has not been performed, a command signal is sent from the reverse rotation detector 6q to the AND gate 6s, and the process proceeds to step F4 in FIG.

In the case of reverse rotation, a command signal is sent from the reverse rotation detecting section 6q to the pulse counter 6r when the rotation of the mounting section on which the encoder 13 is mounted changes from reverse rotation to normal rotation. When this command signal is received by the pulse counter 6r, the output pulse E of the encoder 13 after the rotation of the mounting portion of the encoder 13 changes from reverse rotation to normal rotation.
The number of edges of NC-A and ENC-B is counted.

[0052] The count value _{N 2} is predetermined value (e.g., 5) or more and became time the command signal is output from the pulse counter 6r to the OR gate 6t (see step F3 in FIG. 2). For example Start PF motor 1 at time t ₀ as shown in FIG. 3, the forward rotation after reversed (t ₁₎ the time t
_{In step 2} , the reverse rotation detection unit 6q detects the rotation, and sends a command signal to the pulse counter 6r. When the next pulse edge occurs (time t ₃ ), the number of pulse edges is counted by the pulse counter 6r, and the count value N
_{When 2} becomes N ₂ = 5 (time t ₄ ), a command signal is sent from the pulse counter 6r to the OR gate 6t.

If the mounting portion of the encoder 13 does not rotate in reverse, a command signal is sent from the pulse counter 6p and the reverse rotation detecting portion 6q to the AND gate 6s, respectively, so that the command signal is sent from the AND gate 6s to the OR gate 6t.
Is output to

Therefore, when the mounting portion of the encoder 13 does not reverse, the command signal is supplied from the AND gate 6s, and when the mounting portion is reversed, the command signal is supplied from the pulse counter 6r.
t is input. Then, a speed calculation start command is sent from the OR gate 6t to the speed calculation unit 6d (see step F4 in FIG. 2).

Only after receiving the start command, the speed calculation section 6d starts the speed calculation already described with reference to FIG.

[0056] According to the present embodiment as described above, when the reverse rotation when starting the PF motor 1 to the mounting portion of the encoder 13 occurs, _two predetermined values N after changed from the reverse rotation to the normal rotation Are not used for the speed calculation, and the subsequent pulse edges are used for the speed calculation. Thereby, when the PF motor 1 is started, the encoder 1
The output of the speed calculation unit 6d is accurate even if the attachment portion 3 is reversed.

[0057] In addition, since the to a predetermined value N ₂ pulses edge after changed from the reverse rotation to the normal rotation can not be used for speed calculation, and subsequent pulse edge it is used for speed calculation, P
Even when the mounting portion of the encoder 13 reversely rotates when the F motor 1 is started, it is possible to prevent the timer counter used for the speed calculation of the speed calculation unit 6d from overflowing.

Although the DC motor has been described in the above embodiment, the present invention is not limited to this, and it goes without saying that the present invention can be applied to an AC motor or the like.

[0059] The predetermined value N ₂ is frequently used, etc. of the printing apparatus may be changed by the environmental conditions.

Next, an embodiment of a recording medium on which a motor control program according to the present invention is recorded will be described with reference to FIGS. 12 and 13 are a perspective view and a block diagram, respectively, showing an example of a computer system 130 using a recording medium on which a motor control program according to the present embodiment is recorded. 12, a computer system 130 includes a computer main body 131 including a CPU, a display device 132 such as a CRT,
An input device 133 such as a keyboard and a mouse, and a printing device 134 for executing printing are provided.

As shown in FIG. 13, the computer main unit 131 has an internal memory 135 composed of a RAM and a memory unit 136 that can be built in or externally mounted. The memory unit 136 is a flexible or floppy disk. (FD) drive 137, CD-
ROM drive 138, hard disk drive (H
D) A unit 139 is mounted. As shown in FIG. 12, as a recording medium 140 used in these memory units 136, a flexible disk or floppy disk (FD) 141 inserted into a slot of an FD drive 137 and a CD-ROM drive 138 are used. The used CD-ROM 142 or the like is used.

As shown in FIGS. 12 and 13, as the recording medium 140 used in a general computer system, an FD 141 or a CD-ROM 142 is considered. For example, the control program for the motor of the present invention may be recorded in a ROM chip 143 as a non-volatile memory built in the printing apparatus 134.

The recording medium 140 according to the present embodiment has a procedure for detecting whether or not a reverse rotation has occurred in a mounting portion of the encoder when the motor is started, based on an output pulse of an encoder that rotates in accordance with the rotation of the motor. When reverse rotation occurs in the mounting portion of the encoder, the edge of the output pulse of the encoder after the rotation of the mounting portion of the encoder changes from reverse rotation to normal rotation is counted, and the count value is a first predetermined value. And a procedure for calculating a speed of the motor based on an output pulse of the encoder when the start command is received.

[0064]

As described above, according to the present invention, accurate speed detection can be performed even if reverse rotation occurs in the mounting portion of the encoder when the motor is started.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a motor control device according to the present invention.

FIG. 2 is a flowchart illustrating operation of the embodiment.

FIG. 3 is a timing chart illustrating the operation of a pulse counter.

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

FIG. 5 is a perspective view showing a configuration around a carriage.

FIG. 6 is a schematic diagram showing a configuration of a linear encoder.

FIG. 7 is a waveform diagram of an output pulse of an encoder.

FIG. 8 is a schematic perspective view of the printer illustrating the position of a paper detection sensor.

FIG. 9 is a block diagram showing a configuration of a conventional motor control device.

FIG. 10 is a timing chart illustrating speed control of a conventional motor control device.

FIG. 11 is a diagram illustrating a paper feeding mechanism.

FIG. 12 is a perspective view showing an example of a computer system using a recording medium recording a motor control program according to the present invention.

FIG. 13 is a block diagram showing an example of a computer system using a recording medium recording a motor control program according to the present invention.

[Explanation of symbols]

 1 Paper feed motor (PF motor) 2 Paper feed motor driver 3 Carriage 4 Carriage motor (CR motor) 5 Carriage motor driver (CR motor driver) 6 DC unit 6a Position counter 6b Subtractor 6c Target speed calculator 6d Speed calculator 6e Subtractor 6f Proportional element 6g Integral element 6h Differential element 6j D / A converter 6k Timer 6m Acceleration controller 6p Pulse counter 6q Reverse rotation detector 6r Pulse counter 6s AND gate 6t OR gate 7 Pump motor 8 Pump motor driver 9 Recording head 10 Head Driver 11 Linear encoder 12 Code plate 13 Encoder (rotary encoder) 15 Paper detection sensor 16 CPU 17 Timer IC 18 Host computer 19 Interface unit 20 ASIC 21 PROM 22 RAM 23 EEPROM 25 Platen 30 Pulley 31 Timing belt 32 Guide member of carriage motor 34 Ink cartridge 35 Capping device 36 Pump unit 37 Cap 50 Recording paper 65 Paper feed roller 66 Follower roller 68 Discharge roller 69 Follower roller 80 Spring

Claims (9)

[Claims] 1. A reverse rotation detecting section for detecting whether or not a reverse rotation has occurred in a mounting section to which the encoder is mounted when the motor is started, based on an output pulse of an encoder that rotates in accordance with rotation of the motor; When the reverse rotation occurs, the edge of the output pulse of the encoder after the rotation of the mounting portion changes from the reverse rotation to the normal rotation is counted, and the start command is issued when the count value becomes the first predetermined value. A first pulse counter that outputs, when a reverse rotation occurs in the mounting portion, a speed calculation unit that calculates the speed of the motor based on an output pulse of the encoder when receiving the start command; A control device for a motor, comprising: 2. The method according to claim 1, wherein when the motor is started, an edge of an output pulse of the encoder is counted.
A second pulse counter that outputs a start command when a predetermined value is reached, wherein the speed calculation unit starts outputting from the first pulse counter when the attachment unit reversely rotates. 2. The motor control device according to claim 1, wherein when the reverse rotation does not occur based on the command, the speed calculation is started based on a start command output from the second pulse counter. 3. The motor control device according to claim 1, wherein the motor is a paper feed motor of a printing apparatus. 4. A motor control apparatus according to claim 1, further comprising a speed controller for controlling the speed of said motor based on a deviation between a target speed of said motor and a speed of said motor calculated by said speed calculator. Item 4. A motor control device according to any one of Items 1 to 3. 5. A step of detecting whether or not a reverse rotation has occurred in a mounting portion on which the encoder is mounted when the motor is started, based on an output pulse of an encoder that rotates according to the rotation of the motor; Occurs, the edge of the output pulse of the encoder after the rotation of the mounting portion has changed from reverse rotation to normal rotation is counted, and a start command is output when the count value reaches a first predetermined value. And a step of calculating a speed of the motor based on an output pulse of the encoder when receiving the start command. 6. An edge of an output pulse of the encoder is counted before the step of calculating a speed of the motor, and when the count value becomes a second predetermined value or the mounting portion does not rotate backward. 6. The method according to claim 5, further comprising the step of outputting a start command to the motor. 7. The method according to claim 1, further comprising: after the step of calculating the speed of the motor, controlling the speed of the motor based on a deviation between a target speed of the motor and the calculated speed. The method for controlling a motor according to claim 5. 8. The method according to claim 5, wherein said motor is a paper feed motor of a printing apparatus. 9. A procedure for detecting whether or not a reverse rotation has occurred in a mounting portion on which the encoder is mounted when the motor is started, based on an output pulse of an encoder that rotates in accordance with rotation of the motor; Occurs, the edge of the output pulse of the encoder after the rotation of the mounting portion has changed from reverse rotation to normal rotation is counted, and a start command is output when the count value reaches a first predetermined value. A motor control program for controlling the motor by a computer, comprising: a step of calculating the speed of the motor based on an output pulse of the encoder when the start command is received. Recording medium on which is recorded.