JP3112876B2 - Driving device and method for stepping motor, printer device using this driving device, and driving method therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for a stepping motor using a clutch, and more particularly to a driving device for a stepping motor used in a printer, a copying machine, a facsimile and the like.

[0002]

2. Description of the Related Art In many cases, a paper feed roller of a printer is driven by a stepping motor via a clutch. Further, Japanese Patent Application Laid-Open No. Hei 68884 describes a printer carriage mechanism for connecting a flyhole to a stepping motor via a clutch mechanism.

Conventionally, when a paper feed roller or the like is driven by a stepping motor via a clutch as described above, the clutch is connected and disconnected only when the stepping motor is stopped in order to prevent the stepping motor from falling out of synchronization.
The stepping motor was always started after the clutch was engaged (after connection), and the clutch was disconnected after the stepping motor stopped. That is, the clutch could not be connected or disconnected while the stepping motor was rotating.

[0004]

The conventional driving device for a stepping motor has a problem that the clutch cannot be engaged or disengaged while the stepping motor is rotating.

[0005] The reason is that if the clutch is engaged or disengaged while the stepping motor is rotating, the stepping motor tends to lose synchronism.

SUMMARY OF THE INVENTION The present invention provides a stepping motor driving apparatus and method which does not cause a step out even if switching of connection / disconnection of a clutch connected to the stepping motor is performed during rotation of the stepping motor. It is another object of the present invention to eliminate a stepping motor deceleration time which is conventionally required.

[0007]

A method of driving a stepping motor according to the present invention comprises a stepping motor (2 in FIG. 1).
A clutch (3 in FIG. 1) connected to the output shaft of the stepping motor, a motor buffer register (7 in FIG. 1) for storing a phase pattern to be output to the stepping motor, and connection of the clutch. / A clutch buffer register (9 in FIG. 1) for storing a clutch signal for indicating a disconnection state, and a motor output latch (8 in FIG. 1) in which a stored phase pattern is output to the stepping motor. And a clutch output latch (10 in FIG. 1) in which a stored clutch signal is output to the clutch, and the phase pattern stored in the motor buffer register is taken into the motor output latch. At the same time, the clutch signal stored in the clutch buffer register is transferred to the clutch output register. Characterized by Mukoto, a paper feeding roller of the printer device via the clutch can be connected to the stepping motor.

According to the method of driving a stepping motor of the present invention, a switching of a clutch signal for instructing a connection / disconnection state of a clutch (3 in FIG. 1) connected to the stepping motor (2 in FIG. 1) is output to the stepping motor. It is performed simultaneously with switching of the phase pattern to be performed.

A driving device for a stepping motor according to the present invention.
Is a stepping motor (2 in FIG. 1) and a clutch (3 in FIG. 1) connected to an output shaft of the stepping motor.
And a motor buffer register (7 in FIG. 1) for storing a phase pattern to be output to the stepping motor.
A clutch buffer register (9 in FIG. 1) for storing a clutch signal for instructing a connection / disconnection state of the clutch; and a motor output latch for outputting a stored phase pattern to the stepping motor. (8 in FIG. 1) and a clutch output latch (10 in FIG. 1) in which a stored clutch signal is output to the clutch.
And a central processing unit (1 in FIG. 1). The central processing unit starts the stepping motor interrupt (2 in FIG. 2).
1) Run is instructed to the stepping motor interrupt processing, when connecting the clutch performs the processing of the ON clutch ON request flag (23 in FIG. 2), the clutch ON when disconnecting the clutch A process for turning off the request flag (25 in FIG. 2) is executed, and if the clutch ON request flag is ON in the execution of the stepping motor interrupt process, a clutch signal for connecting the clutch is sent to the clutch buffer register. If the clutch ON request flag is OFF (FIG. 3), a clutch signal for disengaging the clutch is sent to the clutch buffer register (33 in FIG. 3), and the preset phase pattern is changed to the above. Acceleration processing to be sent to the motor buffer register (35 in FIG. 3),
Constant speed processing (36 of nest 3) or deceleration processing (37 of FIG. 3)
After that, the motor output latch and the clutch output latch simultaneously capture the phase pattern and the clutch signal stored in the motor buffer register and the clutch buffer register,
Further, after a pulse time set in advance for each of the acceleration processing, the constant speed processing, or the deceleration processing, execution of the next step motor interrupt processing is repeated.

The paper feed roller of the printer connected to the stepping motor via the clutch can be driven by using the above-described stepping motor driving method.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a driving device for a stepping motor according to an embodiment of the present invention.

In FIG. 1, a CPU (central processing unit) 1
Are ROM (Read Only Memory) 4 and RAM
(Random access memory) 5 and is controlled by a program stored in R0M4 and RAM5. The CPU 1 is connected to the motor buffer register 7 and the clutch buffer register 9 via the internal bus 6, the motor buffer register 7 is connected to the motor output latch 8, and the clutch buffer register 9
It is connected to the clutch output latch 10.

The stepping motor 2 drives a paper feed roller (not shown) via the clutch 3 in four phases. The output latches 8 and 10 are connected to drive circuits (not shown) for the stepping motor 2 and the clutch 3, respectively.

The CPU 1 outputs a phase pattern representing a pulse applied to each phase of the stepping motor 2, and the stepping motor 2 receives this phase pattern via the motor output latch 8 and rotates. The clutch 3 is also connected and disconnected by receiving a clutch signal composed of ON / OFF output from the CPU 1 via the clutch output latch 10 or the like.

The CPU 1 uses a real-time output function and a macro service function to accelerate the stepping motor 2,
Perform constant speed and deceleration rotation. The ROM 4 or the ROM 4 is set in advance by setting in advance a phase pattern consisting of pulses to be sequentially switched and applied to each phase of the stepping motor 2 at the time of acceleration, constant speed, and deceleration rotation.
It is stored in AM5.

When rotating the stepping motor 2,
Start the macro service for that. By the macro service function, a phase pattern set at a preset output timing is output from the CPU 1, passes through the internal bus 6, and is stored in the motor buffer register 7.

The phase pattern is transferred from the motor buffer register 7 to the output latch 8 at the timing set by the real-time output function, and is applied to the drive circuit of the stepping motor 2. By using the macro service function and the real-time function, the stepping motor 2 can be rotated without creating a special program.
Can be stopped.

FIG. 2 is a flowchart showing the operation of the printer for rotating the paper feed roller by the stepping motor 2 of FIG.

In FIG. 2, when the CPU 1 is instructed to start a stepping motor interrupt (step 21), the stepping motor interrupt shown in FIG. 3 is executed by the macro service function, and the operation of the main part of the printer shown in FIG. Regardless, the stepping motor interrupt of FIG. 3 is executed at a preset timing.

On the other hand, the processing of the main section of FIG. 2 is executed independently of the stepping motor interrupt of FIG. 3, and the printing start processing (step 22) is executed after the step 21 of the stepping motor interrupt start to print. Preparations are made.

Next, the clutch ON request flag stored at a predetermined address or the like in the RAM 5 is turned ON (step 23). Thereafter, when the stepping motor interrupt of FIG. 3 is executed, the clutch 3 is connected, the paper feed roller rotates, and the paper is fed from the paper supply unit of the printer to the printing unit (step 24).

Next, after a predetermined time, the clutch ON request flag is turned off (step 25). Thereafter, when the stepping motor interrupt of FIG. 3 is executed, the clutch 3 is disengaged, and the sheet feeding roller stops. Next, a printing process (step 26) is executed.

Steps 23 to 26 are repeated each time paper is fed and printed.

Further, printing of a set of documents is completed,
When paper feeding becomes unnecessary, a motor stop process for stopping the stepping motor 2 after deceleration is executed.

Next, the operation of the stepping motor interrupt shown in FIG. 3 will be described.

In response to the stepping motor interrupt start (step 21) in FIG. 2, or at the timing determined in step 35, 36 or 37 described later, the stepping motor interrupt is started and the state of the clutch ON request flag is checked ( Step 31) If ON, a clutch ON signal for connecting the clutch 3 is output to the buffer register 9 via the internal bus 6 (Step 32), and if OFF, the clutch 3 is disconnected. Is output to the buffer register 9 via the internal bus 6 (step 33).

Next, it is determined whether the driving state of the stepping motor 2 is acceleration, constant speed or deceleration (step 34). If it is acceleration, acceleration processing (step 35)
If the speed is constant, a constant speed process (step 36) is executed. If the speed is decelerated, a deceleration process (step 37) is executed.

The execution of the stepping motor interrupt when receiving the stepping motor interrupt start in step 21 is when the stepping motor 2 is started.
The acceleration processing of step 35 is executed. Thereafter, the stepping motor interrupt is repeatedly executed to drive and accelerate the stepping motor 2, and when the rotation of the stepping motor 2 reaches a preset speed, the constant speed process of step 36 is executed. When decelerating to stop the stepping motor 2, a deceleration process of step 37 is executed.

In the acceleration, constant speed and deceleration processes in steps 35 to 37, the CPU 1 sends the phase pattern to the buffer register 7 via the internal bus 6, and the output latch 8 sends the phase pattern to the drive circuit of the stepping motor 2. Send it out. This phase pattern is a combination of well-known pulse signals for a four-phase stepping motor in which a signal of any phase is switched at the time of signal switching as shown in FIG. 4 and is set in advance. The phase pattern changes sequentially each time the signal is switched. CP for each processing of steps 35 to 37
U1 sends the phase pattern next to the phase pattern at the time of the processing of steps 35 to 37 of the immediately preceding stepping motor interrupt, and continuously executes the stepping motor interrupt a plurality of times, so that the stepping motor 2 as shown in FIG. Drive pulses composed of various waveform groups are applied.

Thereafter, a preset time (this is called a pulse time) after the processing of steps 35 to 37 is completed.
After step elapses, the stepping motor interrupt is executed again.

As a timing for switching the phase pattern of the stepping motor 2, a fixed pulse time is set for the constant speed process in step 36, and a step 3 is performed.
For the acceleration process of No. 5, a sequence of pulse times that becomes shorter in sequence is set, and for the deceleration process of Step 37, a sequence of pulse times that becomes longer in sequence is set.

When the constant speed process of step 36 is executed,
A constant pulse time set for constant speed processing is always used. When the acceleration process of step 35 is executed, the next pulse time in the pulse time train set for the acceleration process with respect to the step time used at the time of the previous stepping motor interrupt is executed to execute the next step motor interrupt. (Short pulse times). When the deceleration process in step 37 is executed, the next pulse time in the pulse time train set for the deceleration process with respect to the step time used at the time of the immediately preceding stepping motor interrupt is executed to execute the next step motor interrupt. Long pulse times).

Immediately after executing the processing of steps 35 to 37, the CPU 1 causes the latch signals to be input to the output latches 8 and 10, and sets the phase patterns stored in the buffer registers 7 and 9 and the ON or OFF clutch. The signals are taken into the output latches 8 and 10 so that the phase patterns and the clutch ON or OFF signals are applied to the drive circuits of the step motor 2 and the clutch 3.

Since the phase pattern and the clutch ON and OFF signals are simultaneously taken into the output latches 8 and 10 by the above-mentioned latch signal, when the clutch ON request flag is turned on in step 23 or the clutch ON request flag is turned on in step 25, When the OFF operation is performed, the phase pattern and the clutch signal applied to the drive circuits of the stepping motor 2 and the clutch 3 are simultaneously switched as shown in FIG. It is performed simultaneously with the switching of the pulse.

The step-out of the stepping motor 2 can be prevented by performing the switching of the clutch 3 at the same time as the switching of the drive pulse of the stepping motor 2 as described with reference to FIG. In FIG. 5, the stator teeth 4 provided with the excitation coil 41 of the stepping motor 2 are shown.
The magnetic field lines 42 between 0 and the rotor teeth 43 are shown.

FIG. 5A shows that a displacement x is generated between the stator teeth 40 and the rotor teeth 43 of the stepping motor 2 and a magnetic force (torque) F is generated in a direction to make the displacement x zero. It shows the state where it is. In this state, when the clutch 3 is switched from the disengaged state to the connected state, a load is suddenly applied to the stepping motor 2, the torque is changed immediately, and the stepping-out is easily performed.

However, when the clutch 3 is switched from the disengaged state to the connected state at the same time as the phase pattern is switched, the clutch 3 is switched when the displacement x shown in FIG. 5B is 0 and the magnetic force is 0. And the torque does not change immediately. Therefore, the latter is less likely to lose synchronism in the latter than in the former.

By utilizing the above, in the present invention, it is possible to switch the clutch without step-out even while the stepping motor 2 is rotating.

In the above description, similarly to the motor output latch 8, the CPU 1 and the motor buffer register 7 output and store a phase pattern composed of a combination of pulses applied to each phase of the step motor 1. However, in these, the CPU 1 outputs phase data consisting of codes representing the phase pattern instead of the phase pattern, and stores the phase data in the motor buffer register 7. The phase data is converted into the phase pattern and output to the motor. Needless to say, the data can be sent to the latch 8.

[0041]

The effect of the present invention is that the connection / disconnection of the clutch connected to the stepping motor can be switched during the rotation of the stepping motor. Therefore, there is no need to stop the stepping motor before the clutch is engaged, and the time for deceleration and stop of the rollers and the like connected to the stepping motor via the clutch is reduced.

The reason is that the switching of the connection / disconnection of the clutch is performed simultaneously with the switching of the phase pattern of the stepping motor, thereby preventing the stepping motor from stepping out.

[Brief description of the drawings]

FIG. 1 is a block diagram of a driving device for a stepping motor according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of a printer device that drives a paper feed roller by a stepping motor 2 in FIG.

FIG. 3 is a flowchart showing a stepping motor interrupt process executed in response to a stepping motor interrupt start in step 21 in FIG. 2;

FIG. 4 is a waveform diagram showing a drive pulse applied to a stepping motor 2 in FIG.

FIG. 5 is a diagram illustrating the principle of torque generation of a stepping motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 2 Stepping motor 3 Clutch 4 ROM5 RAM 6 Internal bus 7 Motor buffer register 8 Motor output latch 9 Clutch buffer register 10 Clutch output latch 40 Stator tooth 41 Exciting coil 42 Magnetic field line 43 Rotor tooth

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02P 8/00 H02P 15/00 B41J 11/42 B65H 23/00

Claims (7)

(57) [Claims] 1. A stepping motor, a clutch connected to an output shaft of the stepping motor, a motor buffer register for storing a phase pattern to be output to the stepping motor, and an indication of a connection / disconnection state of the clutch. A clutch buffer register for storing a clutch signal for performing the operation, a motor output latch for outputting a stored phase pattern to the stepping motor, and a clutch for outputting a stored clutch signal to the clutch. Output latch, and the phase pattern stored in the motor buffer register is taken into the motor output latch, and at the same time, the clutch signal stored in the clutch buffer register is transferred to the clutch output register. Stepping characterized by capturing Motor drive. 2. A method for driving a stepping motor, wherein switching of a clutch signal for instructing a connection / disconnection state of a clutch connected to the stepping motor is performed simultaneously with switching of a phase pattern output to the stepping motor. 3. A stepping motor, a clutch connected to an output shaft of the stepping motor, a motor buffer register for storing a phase pattern to be output to the stepping motor, and an indication of a connection / disconnection state of the clutch. A clutch buffer register for storing a clutch signal for performing the operation, a motor output latch for outputting a stored phase pattern to the stepping motor, and a clutch for outputting a stored clutch signal to the clutch. with a use output latch, a central processing unit, the central processing unit executes a stepping motor interrupt processing is instructed to the stepping motor interrupt start to oN clutch oN request flag when connecting the clutch process When the clutch is disengaged Sets the clutch ON request flag to O.
If the clutch ON request flag is ON during execution of the stepping motor interrupt processing, a clutch signal for connecting the clutch is transmitted to the clutch buffer register, and the clutch ON request flag is turned OFF. Then, after transmitting a clutch signal for disengaging the clutch to the clutch buffer register, an acceleration process, a constant speed process or a deceleration process for transmitting a preset phase pattern to the motor buffer register is executed. Later, the motor output latch and the clutch output latch simultaneously capture the phase pattern and the clutch signal stored in the motor buffer register and the clutch buffer register, and further perform the acceleration process, the constant speed process or the For each deceleration process After the lapse of the order set pulse time,
A driving device for a step motor, which repeats execution of a next step motor interrupt process. 4. A printer device comprising the stepping motor driving device according to claim 1, wherein a sheet feeding roller is connected to said stepping motor via said clutch. 5. Request paper feed roller of the printer device connected to the stepping motor via the clutch section 2
A driving method for a printer device, wherein the driving method is performed by using the driving method for a stepping motor described above . 6. A stepping motor and a stepping motor.
A clutch connected to the output shaft of the
The motor that stores the phase pattern to be output to the ping motor
Data buffer register and connection / disconnection of the clutch
A clutch that stores a clutch signal for indicating a release state
Buffer register and the stored phase pattern
Motor output being output to the stepping motor
The latch and the stored clutch signal are applied to the clutch.
Output latch for clutch output and central processing unit
And the central processing unit is divided by a stepping motor.
Stepping motor split when
When the clutch is engaged, click
Execute the process of turning on the latch ON request flag, and
When disengaging the clutch,
Off the stepping mode.
In the execution of data interrupt processing, the clutch ON request
If the flag is ON, the clutch buffer register
Send a clutch signal to connect the clutch,
If the clutch ON request flag is OFF, the clutch
Clutch buffer to the clutch buffer register.
Switch signal, and then set the phase pattern
Acceleration processing for sending to the motor buffer register,
Constant speed processing or reduction processing is executed, the motor over to subsequent
The output latch for the clutch and the output latch for the clutch.
Motor buffer register and clutch buffer
Phase pattern and clutch stored in register
Signals at the same time.
Preset pulses for speed processing or deceleration processing
After the elapse of time, execute the next step motor interrupt processing
Step mode.
Data driving method. 7. The stepping through the clutch.
7. A paper feed roller of a printer connected to a motor.
Drive using the described stepping motor driving method
A method for driving a printer device, comprising: