JP2000083320A - Apparatus and method for controlling drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize a motor drive voltage for maintaining constant logic voltage, if a motor supply voltage exceeds a specified range, by supplying a current equivalent to the excess to a second motor, and when the motor supply voltage falls back within the specified range, to stop the current supply. SOLUTION: A motor voltage is kept monitored by a VH detection circuit 1 during acceleration, constant-speed running and deceleration of a motor to determine whether the motor voltage has exceeded a set voltage. If it has, the VH detection circuit 1 notifies CPU 102 of that, and the CPU 102 starts excitation of a motor out of operation, or an LF motor 109, via an LF motor driver 107. When the excitation of the motor is started, energy stored as electric charges in a capacitor by energy regenerated from a motor in operation, or a CR motor 108, is discharged via the LF motor 109. The CPU 102 exciting the motor monitors whether the VH voltage fell back below the set value, and causes. If so, excitation to respect to the LF motor 109 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a drive control device and a drive control method for controlling driving of a motor.

[0002]

2. Description of the Related Art Conventionally, as a device having a motor, there is, for example, a facsimile or a printer. Hereinafter, a printer will be described as an example.

In general, there is an inexpensive non-impact printer represented by a bubble jet printer. This non-impact printer controls a printer head, a carriage motor (hereinafter, referred to as a CR motor) for driving the printer head, a paper feed motor (hereinafter, referred to as an LF motor) for feeding paper to be printed, and their movable parts. And a control unit.

In such a non-impact printer,
Cost reduction is often realized by supplying the CR motor and the LF motor from the same power supply.

FIG. 8 shows a configuration example of a non-impact printer.

Here, the printing operation will be described.
When a command is received through the host interface 101, the CPU 102 moves the CR motor 108 to move the printer head 105 to an initial position (home position). Further, the LF motor 109 is moved to set the paper at a predetermined position. At the same time as these operations, the CPU
102 stores the print data sent from the host in the buffer RAM 103. A certain capacity in the buffer RAM 103 (this capacity depends on the structure of the printer head 105, but in the case of a line printer, at least
The CPU 102 starts printing when the data of (the data for the line or more) is stored.

[0007] The CPU 102 includes a CR motor 108.
The printing is performed while moving the printer head 105 in the main scanning direction, and when printing of one line is completed, the LF motor driver 107 feeds the paper by one line in the sub-scanning direction.
These operations are repeated, and when printing of all lines is completed, the paper is completely fed from the printer by the LF motor 109, and printing of one page is completed. If the second page is printed, the same operation is repeated. If the second page is not printed, the CR motor 108 controls the printer head 10
5 is returned to the predetermined position and the process is terminated.

[0008] A series of printing operations are performed in this manner. When printing is performed, the CR motor 108 and the L
The F motor 109 must be operated. Since the CR motor 108 has to move the printer head 105 left and right, it repeats acceleration → constant speed → deceleration → stop → acceleration → constant speed → deceleration. When the LF motor 109 also feeds one line in the sub-scanning direction, acceleration → constant speed →
Execute the operation of deceleration → stop.

FIG. 9 shows the configuration of the power supply unit 110. Here, the linking choke converter method (RC
C) will be described.

Reference numeral 150 denotes a rectifying diode; 151, a primary-side smoothing capacitor; 152, a main switching element;
53 is a resistor, 154 is a capacitor, 155 is a photocoupler, 156 is a switching transistor control element,
57 is a diode.

158 is a transformer, 159 is a secondary side rectifier diode, 160 is a smoothing capacitor, 161 is 3
Terminal regulator, 162 is a secondary side rectifier diode, 1
63 is a smoothing capacitor, 165 is a resistor, 166 is a shunt regulator, 167 and 168 are resistors, and 169 is a smoothing capacitor.

The power output of FIG.
5, CR motor driver 106, LF motor driver 1
07, a VH voltage for the CR motor 108 and the LF motor 109, and a VCC voltage for the control unit. The on / off control of the primary-side transistor is performed through the photocoupler 155 so that the VH voltage becomes the set voltage value.

When the VH voltage rises above the set value, the resistance 1
If the voltage divided at 67 and 168 is equal to or higher than the set value,
The shunt regulator 166 turns on, and a current flows through the photocoupler 155. When a current flows through the photocoupler 155, the transistor 156 is turned on, and the switching element 152 is turned off. When the switching element 152 is turned off, energy is not transmitted from the primary side to the secondary side via the transformer 158, so that the secondary side potential decreases. Conversely, if the VH voltage is equal to or lower than the set value, no current flows through the fat coupler 155, the transistor 156 is turned off, and the switching element 152 is not suppressed, so that energy is transmitted from the primary side to the secondary side. , VH voltages rise.

[0014]

However, when the drive voltage of the motor rises, the following problems occur.

1) If the drive voltage of the motor rises too much,
There is a possibility that element breakdown exceeding the withstand voltage of the motor driver may be caused.

2) If the motor drive voltage rises and the increased voltage reaches the motor supply power supply, the power supply control system may be disrupted.

Here, 2) will be briefly described.

The switching power supply shown in FIG. 9 detects the voltage on the secondary side and outputs a constant voltage by chopping the switch elements 152 and 156 on the primary side so that the detected voltage becomes constant. If the detected voltage is lower than the predetermined voltage, the secondary side output voltage is increased by increasing the on-time of the switch element, and if the detected voltage is higher than the predetermined voltage, the on-time of the switch element is shortened. Control is performed to lower the secondary side output voltage.

The power supply shown in FIG. 9 detects the motor drive voltage and chops the switching elements 152 and 156 on the primary side. A logic voltage is supplied to the printer logic circuit from a three-terminal regulator 161. Here, when the motor is driven, if the motor drive voltage rises due to the back electromotive force of the motor, the voltage of the detection circuit rises above a predetermined voltage, and in conjunction with that, the on-time of the switch element becomes short, and the secondary side output Work in the direction of lowering. When the motor drive voltage decreases, the transformer output voltage for the logic circuit also decreases in conjunction with the decrease. Since the logic voltage is the output of the three-terminal regulator 161, the three-terminal regulator 161
A stable logic voltage can be output even if the transformer output voltage, which is the input voltage of the three-terminal regulator, fluctuates to some extent, but when the input voltage of the three-terminal regulator 161 falls below a certain level, a predetermined logic voltage cannot be output. When the logic voltage drops, there occurs a problem that the control circuit controlling the printer cannot operate stably.
When the back electromotive voltage of the motor increases the motor drive voltage in this way, there is a problem that the printer cannot operate normally.

It is an object of the present invention to provide a drive control device and a drive control method capable of stabilizing a drive voltage of a motor and, thereby, keeping a logic voltage constant.

[0021]

According to the present invention, a first and second motors, a motor power supply for supplying the same voltage to the first and second motors, and a voltage of the motor power supply exceeding a reference range are provided. Motor voltage determining means for determining whether or not
Supply means for supplying a current corresponding to an amount exceeding the reference range to the second motor when the voltage of the motor power supply exceeds a reference range while driving the first motor; And a control means for stopping the current flowing to the second motor when is returned to the reference range, thereby constituting a drive control device.

Further, the present invention constitutes an image forming apparatus by including the drive control device and image forming means for forming an image using the first and second motors of the drive control device. .

Also, the present invention is a method for performing drive control using at least first and second motors, wherein the same power is supplied to the first and second motors by a motor power supply; Determining whether the power of the motor power supply has exceeded a reference range; and, while driving the first motor, when the power of the motor power supply has exceeded a reference range.
Supplying power corresponding to the amount exceeding the reference range to the second motor, and stopping the power supplied to the second motor when the power of the motor power supply returns to the reference range. And a driving control method is provided.

Also, the present invention is a method for performing drive control using at least first and second motors, the method comprising: supplying the same voltage to the first and second motors by a motor power supply; Determining whether or not the voltage of the motor power supply has exceeded a reference range; and, while driving the first motor, when the voltage of the motor power supply has exceeded a reference range.
Flowing a current corresponding to the amount exceeding the reference range to the second motor, and stopping the current flowing to the second motor when the voltage of the motor power supply returns to the reference range. By providing, a drive control method is provided.

Further, the present invention provides an image forming method by forming an image by an image forming means using the first and second motors driven and controlled by the drive control method.

The present invention is also a medium in which at least a first and a second motor are used and a control program for controlling the drive of the motor by a computer is recorded. To supply the same power to the first and second motors, to determine whether or not the power of the motor power supply has exceeded a reference range. During the driving of the first motor, the power of the motor power supply is When the power exceeds the reference range, the power corresponding to the amount exceeding the reference range is supplied to the second motor, and when the power of the motor power supply returns to the reference range, the power supplied to the second motor is reduced. By stopping, a recording medium on which a drive control program is recorded is provided.

Further, the present invention is a medium in which at least a first and a second motor are used and a control program for controlling the drive of the motor by a computer is recorded, wherein the control program includes a motor power supply. To supply the same voltage to the first and second motors, determine whether the voltage of the motor power supply has exceeded a reference range, and while driving the first motor, the voltage of the motor power supply If the voltage exceeds the reference range, a current corresponding to the amount exceeding the reference range is supplied to the second motor, and when the voltage of the motor power supply returns to the reference range, the current supplied to the second motor is reduced. By stopping, a recording medium on which a drive control program is recorded is provided.

Here, the image forming means may have a printer section for printing on transfer paper by a printer head.

The first motor comprises a carriage motor for moving the printer head in the main scanning direction.
The second motor may be a paper feed motor that feeds the transfer paper in the sub-scanning direction.

The first motor may be a paper feed motor for feeding the transfer paper in the sub-scanning direction, and the second motor may be a carriage motor for moving the printer head in the main scanning direction. it can.

[0031]

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

FIG. 1 is a printer showing an example of a configuration as a drive control device according to the present invention. In this example, a description will be given by taking a non-impact printer similar to that of FIG. 8 described above as an example, and the same portions are denoted by the same reference numerals. The drive control device is not limited to a non-impact printer.

In FIG. 1, reference numeral 101 denotes a host interface (I / F) for transferring commands and data from a host (such as a personal computer). A CPU 102 controls the entire printer. A buffer RAM 103 stores commands and data transferred by the host interface 101.

Reference numeral 104 denotes a head print control unit for controlling the head by formatting data to be printed according to the head structure. A printer head 105 prints data. Reference numeral 106 denotes a CR motor driver that controls the CR motor 108. An LF motor driver 107 controls the LF motor. 108 is a CR motor. Reference numeral 109 denotes an LF motor.

Reference numeral 110 denotes a printer head 105, CR motor driver 106, LF motor driver 107, CR
The power supply unit supplies power to the motor 108, the LF motor 109, and each control unit.

Reference numeral 1 denotes a VH detection circuit that monitors the voltage VH and notifies the CPU 102 when the voltage VH exceeds a set value.

First, an outline of the operation of the present apparatus will be described.

When a command is received through the host interface 101, the CPU 102
To move the printer head 105 to the initial position (home position). Further, the LF motor 109 is moved to set the paper at a predetermined position. At the same time as these operations, the CPU 102 stores the print data sent from the host in the buffer RAM 103. Buffer RAM
103 has a certain capacity (this capacity is
5 depends on the structure, but in the case of a line printer,
When data of at least one line or more is stored, the CPU 102 starts printing.

The CPU 102 has a CR motor 108
The printing is performed while moving the printer head 105 in the main scanning direction, and when printing of one line is completed, the LF motor driver 107 feeds the paper by one line in the sub-scanning direction.
These operations are repeated, and when printing of all lines is completed, the paper is completely fed from the printer by the LF motor 109, and printing of one page is completed. If the second page is printed, the same operation is repeated. If the second page is not printed, the CR motor 108 controls the printer head 10
5 is returned to the predetermined position and the process is terminated.

A series of printing operations are performed in this manner. When printing is performed, the CR motor 108 and the L
The F motor 109 must be operated. Since the CR motor 108 has to move the printer head 105 right and left, it repeats acceleration → constant speed → deceleration → stop → acceleration → constant speed → deceleration.

(Principle of the Invention) Next, the reason why the VH detection circuit 1 is provided will be described.

In the printer, the CR motor 108, L
As the F motor 109, a DC motor or a stepping motor is used, and a low-cost printer often uses an inexpensive stepping motor that is easy to control. The control method of this stepping motor is classified into a constant voltage drive method and a constant current drive method.

In the constant voltage driving method, as shown in FIG. 9, one transistor is driven per phase, and the current flowing through the motor is not controlled by feed hack. In the constant current driving method, a circuit as shown in FIG. 3 converts a current into a voltage with a sense resistor so that the current flowing through the motor is constant, and makes the voltage detected by the sense resistor equal to the reference voltage. The switching transistor is chopped. The constant current driving method includes a unipolar driving shown in FIG. 3 and a bipolar driving shown in FIG.

In the bipolar driving method, current chopping includes a) a slow decay method and b) a fast decay method.

When current chopping is performed by the slow decay method shown in FIG. 5, ignoring the mutual inductance of the motor and the back electromotive voltage generated from the rotating motor, L * dI / dt + Ron * I + VF = 0 (1) To establish.

On the other hand, in the fast decay method shown in FIG. 6, under the same conditions as in the equation (1), L * dI / dt + 2 * VF + Rs * I = VM (2) L: motor inductance VF: diode forward voltage Rs: sense resistance value is established.

From the differential equations (1) and (2), the current I
Is obtained on the time axis, as shown in FIG. This FIG.
It can be seen that the fast decay has the ability to reduce the motor current rapidly. In particular, this tendency becomes remarkable when the motor inductance is large. Thus, when the motor current is rapidly reduced or a motor having a large motor inductance is controlled, the fast decay method is an effective means.

However, in the first decay method, the energy stored in the motor inductance is fed back to the motor power supply, thereby realizing a sharp decrease in the motor current. When the current energy stored in the inductance of the motor is fed back to the motor power supply side in this way, the current energy is stored as charge energy of the capacitor, and an increase in the charge of the capacitor results in an increase in the motor drive voltage. The increase in the motor drive voltage causes the above-described problem.

Therefore, in the present invention, the electric charge fed back from the motor to the motor power supply side and stored in the capacitor (the stored electric charge corresponds to an increase in the motor drive voltage) is released to another motor. This constitutes control means. As one of the control means, the VH detection circuit 1 shown in FIG. 1 is included.

(Driving Control of the Present Invention) Hereinafter, the control processing by the control means including the VH detection circuit 1 according to the present invention will be described with reference to FIG.
A description will be given based on the flowchart of FIG. This control process is executed mainly by the CPU 102 in FIG.

In step S1, the motor is accelerated / constant speed /
During the deceleration operation, the motor voltage is always monitored by the VH detection circuit 1. The monitored motors include, for example, the CR motor 108 and the LF motor 109. Here, it is assumed that the CR motor 108 is operating.

In step S2, it is determined whether or not the motor voltage has exceeded the set voltage. If the motor voltage has exceeded the set voltage, the process proceeds to step S3.

At step S3, the VH detection circuit 1
Notify U102 of the exceeded state.

In step S 4, the CPU 102, having received the notification from the VH detection circuit 1, starts exciting the motor which is not operated, that is, the LF motor 109 via the LF motor driver 107.

By the start of the motor excitation, the energy stored in the capacitor as electric charge by the energy regenerated from the operating motor, that is, the CR motor 108, is discharged through the LF motor 109.

In this case, if the motor is a stepping motor, the rotation of the rotor does not occur only by the excitation.
Excitation during printing does not adversely affect the print itself.

In step S5, the CPU during motor excitation
102 monitors whether or not the VH voltage has returned to within the set value, and proceeds to step S6 when the VH voltage returns to within the set value.

In step S6, the excitation of the LF motor 109 is stopped because the VH voltage is within the set value.

In the above example, the VH voltage rise due to the fast decay is detected, and the excitation of the other motor is turned on.
By performing the off control, the increased voltage is discharged. As another example, for example, another motor can be excited in advance, and when the VH voltage exceeds a set value, the exciting current can be increased to discharge the increased voltage.

From the above example, by discharging the electric charge stored in the capacitor to the other motor, it is possible to prevent the motor driver from being destroyed by 1) the voltage rise due to the fast decay, and 2) the voltage rise due to the fast decay. In addition, it is possible to realize an effect that it is possible to prevent adverse effects on the switching power supply.

The present invention can be implemented not only by software means but also by hardware means. Further, in the above example, an example in which control is performed using a voltage has been described, but the present invention is not limited to this method.

The present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, and a printer).
The present invention may be applied to an apparatus including two devices (for example, a copying machine and a facsimile machine).

It is needless to say that the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. Then, a storage medium storing a program represented by software for achieving the present invention is supplied to a system or an apparatus, and the computer (or CPU or M) of the system or the apparatus is supplied.
PU) can read and execute the program code stored in the storage medium, so that the effects of the present invention can be enjoyed.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, magnetic tape, nonvolatile memory card, ROM
(A mask ROM, a flash EEPROM, or the like) can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written in the function expansion port inserted into the computer or the memory provided in the function expansion unit connected to the computer, the program code is read based on the instruction of the program code. It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0068]

As described above, according to the present invention,
If the power supply voltage for driving rises while driving one motor, the charge of the increased voltage is discharged to the other motor, and the motor driving voltage is kept within a certain range. The control system of the power supply to be driven can be kept stable, and the printing operation can be performed normally while the logic voltage is kept constant.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating a motor control method.

FIG. 3 is a circuit diagram showing a unipolar driving method.

FIG. 4 is a circuit diagram showing a bipolar driving method.

FIG. 5 is a circuit diagram showing slow decay type current chopping.

FIG. 6 is a circuit diagram showing fast decay type current chopping.

FIG. 7 is a characteristic diagram showing a current decay mode.

FIG. 8 is a block diagram showing a configuration of a conventional motor control unit.

FIG. 9 is a circuit diagram showing a configuration of a power supply unit.

[Explanation of symbols]

 1 VH detection circuit 102 CPU 105 Printer head 106 CR motor driver 107 LF motor driver 108 CR motor 109 LF motor

Claims (15)

[Claims] 1. A first and second motor, a motor power supply for supplying the same voltage to the first and second motors, and a motor voltage for determining whether a voltage of the motor power supply has exceeded a reference range. Determining means for supplying a current corresponding to an amount exceeding the reference range to the second motor when the voltage of the motor power supply exceeds a reference range while driving the first motor; And a control means for stopping the current flowing to the second motor when the voltage of the motor power supply returns to the reference range. 2. An image forming apparatus, comprising: the drive control device according to claim 1; and an image forming unit configured to form an image by using first and second motors of the drive control device. 3. An image forming apparatus according to claim 2, wherein said image forming means has a printer unit for printing on transfer paper by a printer head. 4. The first motor comprises a carriage motor for moving the printer head in a main scanning direction, and the second motor comprises a paper feed motor for feeding the transfer paper in a sub scanning direction. 4. The image forming apparatus according to claim 3, wherein: 5. The first motor comprises a paper feed motor for feeding the transfer paper in a sub-scanning direction, and the second motor comprises a carriage motor for moving the printer head in a main scanning direction. 4. The image forming apparatus according to claim 3, wherein: 6. A method of performing drive control using at least first and second motors, comprising supplying the same power to the first and second motors by a motor power supply, and powering the motor power supply. Judging whether or not exceeds a reference range; and, while driving the first motor, when the power of the motor power supply exceeds the reference range, the power corresponding to the amount exceeding the reference range is reduced to the second power. And a step of stopping the power supplied to the second motor when the power of the motor power supply returns to a reference range. 7. A method for performing drive control using at least first and second motors, comprising supplying a same voltage to the first and second motors by a motor power supply, and a voltage of the motor power supply. Judging whether or not exceeds a reference range, and, while driving the first motor, when the voltage of the motor power supply exceeds the reference range, the current corresponding to the amount exceeding the reference range And a step of stopping the current flowing to the second motor when the voltage of the motor power supply returns to a reference range. 8. An image forming method, wherein an image is formed by an image forming means using first and second motors driven and controlled by the drive control method according to claim 6. 9. An image forming method according to claim 8, wherein said image forming means has a printer unit for printing on transfer paper by a printer head. 10. The first motor comprises a carriage motor for moving the printer head in a main scanning direction, and the second motor comprises a paper feed motor for feeding the transfer paper in a sub-scanning direction. The image forming method according to claim 9, wherein: 11. The first motor comprises a paper feed motor for feeding the transfer paper in the sub-scanning direction, and the second motor comprises a carriage motor for moving the printer head in the main scanning direction. The image forming method according to claim 9, wherein: 12. A medium in which at least a first motor and a second motor are used and a control program for performing drive control of the motor by a computer is recorded, the control program being provided to a computer from a motor power supply to the first motor. And the second motor is supplied with the same power, and it is determined whether or not the power of the motor power supply exceeds a reference range. If the power of the motor power supply exceeds the reference range while driving the first motor, Causing the second motor to supply power corresponding to the amount exceeding the reference range, and stopping the power supplied to the second motor when the power of the motor power supply returns to the reference range. A recording medium on which a drive control program is recorded. 13. A medium recording at least a first and a second motor and recording a control program for performing drive control of the motor by a computer, the control program comprising: And supplying the same voltage to the second motor, and determining whether or not the voltage of the motor power supply has exceeded a reference range. If the voltage of the motor power supply has exceeded the reference range while driving the first motor, Causing the current corresponding to the amount exceeding the reference range to be supplied to the second motor, and stopping the current supplied to the second motor when the voltage of the motor power supply returns to the reference range. A recording medium on which a drive control program is recorded. 14. The printer according to claim 1, wherein the first motor comprises a carriage motor for moving the printer head in the main scanning direction, and the second motor comprises a paper feed motor for feeding the transfer paper in the sub-scanning direction. 14. A recording medium on which the drive control program according to claim 12 is recorded. 15. The printer according to claim 15, wherein the first motor comprises a paper feed motor for feeding the transfer paper in the sub-scanning direction, and the second motor comprises a carriage motor for moving the printer head in the main scanning direction. 14. A recording medium on which the drive control program according to claim 12 is recorded.