JPS59149796A - Control system for stepping motor - Google Patents

Abstract

PURPOSE:To accurately stop a carriage at an end position by detecting the exciting phase of a stepping motor in the state that the carriage reaches the end position. CONSTITUTION:When a carriage C reaches an end position E, it detects which phase a step motor is excited in or not. If it is 2-phase excited state, the carriage is returned as it is. If it is 1-phase excited state, it is returned to 2-phase excited state, and then the carriage is returned, thereby eliminating the inconvenience that the carriage C excessively moves over the end position E or generates a vibration at the end position, thereby effectively operating the carriage.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a control method for a stepping motor, and further relates to (
In particular, the present invention relates to a control system for a stepping motor of a recording apparatus that uses a stepping motor to constitute a main scanning drive system.

BACKGROUND ART In general, so-called semi-multi-type facsimile machines, printers, typewriters, and other recording devices in which a carriage with a reading and recording head reciprocates in the main scanning direction use a four-phase stepping motor as the main scanning drive source. I am using it.

Then, the 1-2 phase excitation force type is used for detailed control such as reading and recording, and the 2-phase excitation force type is used when high torque is required at high speeds such as during carriage return. , the phase excitation method is switched as necessary.

A conventional control method of this type will be explained using the first factor.

In FIG. 1, the range indicated by the symbol X is the traveling interval of the carriage C, and the range indicated by the symbol y is the recording or reading range.

Further, the symbol A indicates a carrying portion that employs a 1-2 phase excitation force type.

Further, the symbol H indicates the home position, and the symbol E indicates the end position.

On the other hand, the recording device has one or more sensors to detect and control the position of the carriage C.

In the first factor, the carriage C advances from the home position H, which can be determined by the sensor, to the end position E, which can be determined by the sensor, while recording or reading by driving the stepping motor in forward rotation using the 1-2 phase excitation method.

Of course, in addition to the method of detecting the end position using a sensor (2), the end position E may also be determined by counting the number of pulses of the stepping motor during the travel range X of the carriage.

When the carriage C reaches the end position E, the stepping motor is switched to the two-phase excitation mode (two-phase switching and reverse drive) to perform a carriage return and return to the home position H.

However, if such a method is adopted, since the 1-2 phase excitation method repeats l-phase excitation and 2-phase excitation for each pulse, it becomes difficult to determine which phase is being excited when the carriage leaves the home position. Therefore, there are cases where the number of phase excitations is one phase and two phases when the carriage reaches the end position.

When the carriage reaches the end position E, if the number of phase excitations is two phases, the rotation can be reversed as is, but if it is one phase, it is necessary to change it to two phases. However, in this case, with conventional devices of this kind, the previous excitation phase was ignored and two new phases were excited, and then rotation was started using the two-phase excitation method, so the difference between the previous excitation phase and the new excitation phase was There is a gap of several pulses between the two, which causes the carriage C to go too far beyond the end position E, and causes rattling and noise at the end position.

Purpose The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional technology. An object of the present invention is to provide a stepping motor control method for a recording apparatus that can perform recording by controlling the motor.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to two examples shown in the drawings.

FIGS. 2 and 3 show an embodiment of the present invention, and FIG. 2 (a professional diagram of the screamer control circuit) is shown.

As is clear from FIG. 2, the present invention uses a CPU (Central Processing Unit) to control the stepping motor.

The CPU receives the sensor output of the home position and the sensor output of the end position through Pl and P2, respectively, and constantly recognizes the position of the carriage. Phase excitation of the stepping motor S is controlled via the I/F.

A timer T is connected to the CPU, and a pass line B
Information is exchanged between ROM (fixed storage device) and RAM (random access memory) via L.

Next, the actual control operation will be explained using the flow chart shown in FIG.

First, when the operation starts, 1-
Recording or reading is started by rotating the stepping motor forward by one pulse using the two-phase excitation method.

Then, in step S2, it is determined whether the carriage has reached the end position. If the carriage has reached the end position, it is determined in step S3 whether or not the stepping motor is in a one-phase excitation state.

If it is not in the one-phase excitation state, that is, in the two-phase excitation state, the process proceeds to step S6, where the stepping motor is reversed by one pulse using the two-phase excitation method, and then a carriage return operation is performed. Then, the process advances to step S4, and it is determined whether the home position has been reached.

If it is determined that the home position has been reached, one main scanning operation ends.

If it is determined that the home position has not been reached, the process returns to step S6.

By the way, if it is determined in step S3 that the state is in the 1-phase excitation state, the process proceeds to step S5, and the stepping motor is reversed by one pulse in the 1-2 phase excitation blade type state. Then, the state is returned to the two-phase excitation state, and step S6 ('
'', the stepping motor is reversed by one pulse using the two-phase excitation blade type, and then carriage return is started, and one main scan is completed through step S4.

In this way, when the carriage reaches the end position in a 1-2 phase excitation blade type (2) recording device that also drives the stepping motor to perform recording and reading, and a 2 phase excitation blade type (2) recording device that performs carriage return. It detects in which phase the stepping motor is in the excitation state, and if it is in the two-phase excitation state, the carriage return is performed as is.(7) Then, the carriage return is performed. A gap of several pulses is less likely to occur between the previous excitation phase and the new excitation phase, eliminating inconveniences such as the carriage going too far beyond the end position or generating vibrations at the end position, and ensuring reliable carriage operation. You can create movements.

In addition, in the above-mentioned embodiment, switching of the phase excitation at the time when the carriage reaches the end position was explained as an example, but it is also possible to switch the phase excitation at the time when the carriage reaches the end position.
The excitation phase of the stepping motor can be switched from any position that can be determined by counting the number of pulses of the stepping motor with respect to the distance traveled from the home position.

If such a system is adopted, the carriage can be returned to the home position at high speed when there is no recording or reading portion.

Effect (8) As is clear from the above explanation, according to the present invention, the excitation phase of the stepping motor is detected when the carriage has reached the end position, and if the excitation phase is the same as the excitation phase at the time of carriage return, the carriage is moved as it is. If not, the carriage return is performed after aligning with the excitation phase of the carriage return, so the carriage can be accurately stopped at the end position, and the carriage can be stopped due to overrun or vibration. Noise can also be reduced.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is an explanatory diagram of the operation of a carriage in a recording apparatus in which the present invention is achieved, FIG. 2 is a block diagram of a control circuit explaining one embodiment of the present invention, and FIG. Flowchart C for explaining the control operation in the present invention: Carriage
CPU...Central processing unit S...Stepping motor Figure 1 1 B 3rd section 1 Hearing difficulty 1 1 1 l Sl] Sl: Kumota forward rotation χ) 1 52 1
End, tS・-N. --Is it 1 ton?

Claims (1)

[Claims] In a stepping motor control system for a recording device in which a stepping motor is driven by a 1-2 phase excitation force type to perform recording and reading, and a carriage return operation is performed by a 2 phase excitation force type, the time when the carriage reaches the end position ( A stepping motor control method characterized in that the number of excitation phases of the stepping motor at the second step is detected, and if the number of excitation phases is different from the number of excitation phases at the time of carriage return, the number of excitation phases is adjusted to that number before carriage return is performed.