JPH0798412B2 - Recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus, and more particularly to a serial type recording apparatus that uses a step motor as a drive source to move at least a recording head for recording scanning. is there.

[Prior Art] In a conventional serial type printing apparatus, a hybrid type or PM (permanent magnet) type step motor is often used as a carriage drive motor for driving a carriage that conveys a print head for print scanning. . The drive control of the step motor is performed by simply performing open loop control of the number of drive pulses of the motor and the frequency of the pulse. In addition to the step motor, a DC brush motor may be used as the carriage driving motor.

[Problems to be Solved by the Invention] However, when a stepper motor is used as a carriage drive motor and is driven by open loop control, "Kean Annoying noise is generated. Also, when the carriage is started, stopped, and reversed, that is, when the step motor is started, stopped, and reversed, the step motor vibrates and starts or stops, which causes a loud noise. These noises become a problem particularly in a printer that does not generate much noise, such as an inkjet printer such as a bubble jet printer.

On the other hand, when a DC brush motor is used as a carriage drive motor, there is no problem in terms of noise, but the contact point between the brush and commutator is long, and there is a difficulty in reliability. In particular, computer output that requires sufficient durability There was a problem as a device. In addition, the cost of the DC brush motor was relatively high in spite of its difficulties.

It is also conceivable to use a brushless motor as another carriage drive motor, but with a brushless motor, the startup time at startup is long and it starts almost every line.
It was not suitable as a carriage drive motor that repeatedly stops and recoils. That is, if a brushless motor is used, high speed recording cannot be performed.

An object of the present invention is to solve the above-mentioned drawbacks and to provide a recording apparatus that is capable of high-speed recording with low noise and is excellent in reliability and durability.

[Means for Solving the Problems] In order to solve the above problems, according to the recording apparatus of the present invention, a carriage on which a recording head is mounted, a step motor for moving the carriage, and a rotor of the step motor are provided. Detecting a rotational angle position of the rotor, generating a pulse signal for each rotation of the rotor by a predetermined angle, and counting pulse signals from the detecting means, and detecting the position of the carriage according to the count value. Along with the control means for outputting control signals for starting and stopping the carriage, and counting a plurality of pulse signals from the detection means,
Switching means for controlling the excitation phase switching of the excitation current supplied to the coil of the step motor according to the count value, and the switching means controls the excitation phase switching of the excitation current by the start control signal from the control means. A structure is adopted in which the excitation phase switching control of the excitation current is stopped by the start and stop control signals.

[Operation] According to such a configuration, a plurality of pulse signals generated from the detecting means are counted each time the rotor of the step motor rotates by a predetermined angle, and the exciting current supplied to the coil of the step motor is counted according to the counted value. By controlling the excitation phase switching, the excitation phase can always be switched at the optimum timing, the step motor can be driven smoothly, vibration during driving and during start-up and stop can be suppressed, and noise can be reduced.

In addition, since there is no step out, a high frequency can be selected as the frequency of the drive pulse of the step motor, the step motor can be driven at high speed, and high speed recording becomes possible.

In addition, step motors do not have the problem of contact life as DC brush motors do.

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

First Embodiment FIGS. 1 to 4 are for explaining the structure and operation of the portion of the serial type ink jet printer according to the first embodiment of the present invention related to the present invention.

First, FIG. 1 shows the structure of a carriage drive mechanism that drives a carriage on which a recording head is mounted, as a main part of the printer of the embodiment. In the figure, reference numeral 2 is a carriage, which is equipped with an inkjet type recording head 4, and is mounted on guide shafts 5a and 5b which are installed in parallel with a platen (not shown) which serves as a recording base for recording paper 7 in the printer. It is slidably supported in the axial direction. Further, a belt 6 is coupled to the carriage 2, the belt 6 is stretched between pulleys 3a and 3b, and the pulley 3a is coupled to an output rotation shaft of the carriage drive motor 1.

When the pulley 3a is rotationally driven by the carriage driving motor 1, the belt 6 travels, and in conjunction with this, the carriage 2 causes the carriage 2 to travel over the guide shafts 5a and 5b.
The carriage 2 slides along the direction of arrow F or R, and the recording head 4 moves while the carriage 2 moves once in the direction of F or R.
Is driven to record one line of dots,
When the recording of one line is completed, the recording paper 7 for one line is sent upward in the figure and a line feed is made. By repeating this, the recording is performed line by line.

An example of the drive conditions required for the carriage drive motor 1 during this recording operation is as follows. The rotation speed of the carriage drive motor 1 corresponding to the recording speed when the recording density is 360 dots / inch is about 800 rpm in the high speed mode. Yes, about 400 rpm in low speed mode. In high-speed mode, the time required to reach constant speed running (rotation speed 800 rpm) is about 60 msec, the constant speed running time is about 1 second, and the time from constant speed running to stop is about 60 msec.

Next, FIG. 2 is a cross-sectional view for explaining the structure of the carriage drive motor 1 of the present embodiment driven under the above drive conditions.

In the structure shown in FIG. 2, reference numerals 10a and 10b denote bodies for supporting the entire carriage drive motor 1, which are vertically opposed to each other and coupled by screws 11 or the like and fixed to each other.

A rotor shaft 13 as an output rotating shaft of the motor 1 is rotatably supported by the bodies 10a and 10b via bearings 12a and 12b, and a rotor 14 formed of a cylindrical permanent magnet is provided in the center of the rotor shaft 13. Is stuck. On the outer circumference of the rotor 14, magnetic poles of N poles and S poles are alternately magnetized at equal pitches in the circumferential direction, for example, 24 poles in this case.

Next, outside the rotor 14, two ring-shaped stators 16a and 16b, each having coils 15a and 15b wound respectively, are vertically stacked so that the rotor 14 is loosely fitted in the central opening of each body 10a. It is sandwiched and fixed between 10b. The inner circumferences of the stators 16a and 16b facing the outer circumference of the rotor 14 are
Magnetic poles are provided at the same pitch as the above magnetic poles of the rotor 14. The magnetic poles of the stator 16a and the stator 16b are arranged so as to be displaced from each other in the circumferential direction by 1/4 of the pitch of the magnetic poles.

Under such a structure, by switching the exciting currents of the coils 15a and 15b by, for example, a well-known two-phase excitation method, attraction and repulsion due to magnetic force between the magnetic poles of the stators 16a and 16b and the magnetic poles of the rotor 14 are performed. As a result, the rotor 14 rotates together with the rotor shaft 13. As described above, the number of magnetic poles of the rotor 14 is N pole, S pole 24
The rotor 14 is switched by switching the exciting current 48 times for each pole.
Rotates once.

The positions of the magnetic poles of the stators 16a and 16b are shifted as described above, so that the rotors 14 can be rotated in any of their circumferential directions by reversing the excitation order of the stators 16a and 16b.

By the way, the basic structure of the carriage drive motor 1 described above is the same as that of the conventional PM type step motor.
In addition to the basic structure as a mold step motor, the carriage drive motor 1 of this embodiment has an encoder for detecting the rotational angle position of the rotor 14, that is, the position of each magnetic pole of the rotor 14 in order to realize low noise and high speed drive. It is provided.

This encoder consists of a detection disk 17 fixed to the rotor shaft 13 and an MR fixed to the body 10b facing the outer circumference of the detection disk 17.
An element (magnetoresistive element) substrate 18 is provided. In the outer circumference of the detection disk 17, magnetic poles of N pole and S pole are alternately magnetized at equal pitches, in this case, for example, 144 poles are magnetized. Although not shown, on the surface of the MR element substrate 18 facing the detection disk 17, two MR elements are provided adjacent to each other at a position slightly shifted in the circumferential direction of the disk 17.

Then, the disk 17 rotates with the rotation of the rotor 14, and every time the magnetic pole of the disk 17 passes in front of the two MR elements on the MR element substrate 18, pulse signals different in phase from each other by 90 ° are transmitted through both elements. It is designed to be output as the output of the encoder. As described above, the number of magnetic poles of the detection disk 17
The number of output pulses of the encoder for one rotation of the rotor 14 as 144 is 288. It should be noted that the reason why the pulses having 90 ° different phases are output via the two MR elements is to detect the rotation direction of the rotor 14.

In the present embodiment, the drive of the carriage drive motor 1 is closed-loop controlled according to the detection output of such an encoder. Specifically, the coil 15a of the carriage drive motor 1,
The switching timing of the exciting current of 15b and the rotation speed are controlled.

Next, FIG. 3 illustrates the configuration of a motor drive control system for performing closed loop control of the carriage drive motor 1.

In FIG. 3, reference numeral 20 is an MP for controlling the entire printer.
A U (microprocessor unit) 20, which uses a RAM (random access memory) 22 for data processing according to a control program stored in a ROM (read only memory) 21 to drive other mechanisms (not shown) of the printer. The drive control of the power source is performed, and the drive control of the carriage drive motor 1 that drives the carriage 2 is performed. Therefore, the MPU 20 detects the position of the carriage 2 by counting the output pulses of the encoder 25 composed of the detection disk 17 and the MR element substrate 18 described above using a counter composed of hardware or software (not shown). It is supposed to do.

Then, the MPU 20 controls the rotation speed of the carriage drive motor 1 to the speed in the high speed mode or the low speed mode described above through the motor speed control circuit 23, and switches the exciting currents of the coils 15a and 15b of the carriage drive motor 1 to carry the carriage. Via the current switching circuit 24 which drives the drive motor 1, the start, stop and rotation direction of the carriage drive motor 1, that is, the start, stop and movement direction of the carriage 2 are controlled.

The motor speed control circuit 23 performs closed loop control of the rotation speed of the carriage drive motor 1 according to the detection output of the encoder 25, and specifically, compares the interval time of the output pulse of the encoder 25 with a reference time, According to the comparison result, the magnitude of the exciting current or the magnitude of the voltage of the carriage drive motor 1 is adjusted so as to reduce and eliminate the time difference. A circuit that performs such a function is already known, and a detailed description thereof will be omitted here.

The MPU 20 indicates the rotation speed of the carriage drive motor 1 to the motor speed control circuit 23, and the reference time for comparison corresponding to the instructed speed is selected in the motor speed control circuit 23 accordingly. It is used for comparison with the pulse interval, and the rotation speed of the carriage drive motor 1 is controlled to, for example, a predetermined high speed mode or a predetermined low speed mode.

On the other hand, the current switching circuit 24 starts the switching operation of the exciting current described above in response to the activation signal input from the MPU 20 to activate the carriage drive motor 1 and activates the carriage drive motor 1 in response to the stop signal input from the MPU 20. Stop. In this case, as a method of stopping the carriage drive motor 1, both ends of the coil of the motor 1 are short-circuited. As a result, the carriage drive motor 1 becomes the same as a generator, and the kinetic energy given from the carriage 2 is converted into electric energy for power generation and further converted into heat energy and absorbed promptly, so that the carriage drive motor 1 smoothly and quickly. Stop. With this method, noise generated when the carriage drive motor 1 is stopped, that is, when the carriage 2 is stopped can be effectively suppressed.

Further, the current switching circuit 24 not only drives and stops the carriage drive motor 1 as described above, but also relates to the present invention, and the switching timing of the excitation current of the coil of the carriage drive motor according to the detection output of the encoder 25. Closed loop control. For this reason, the current switching circuit 24 has a counter (not shown), which counts the output pulses of the encoder 25 and, when the count value matches a predetermined value, switches the exciting current at that time. Has become. As described above, the number of times the current of the carriage drive motor 1 is switched is set to 48 times per revolution of the rotor 14 by the two-phase excitation method, and the number of output pulses of the encoder 25 is set to 288 pulses per revolution. Since the roller 14 rotates by an equal angle each time one pulse is output, if the exciting current is switched every time 6 pulses (288 ÷ 48) are counted, the roller 14 always rotates by an equal angle. The exciting current is switched at the timing when the positional relationship between the magnetic poles of the rotor 14 and the magnetic poles of the stators 16a and 16b becomes the same predetermined timing. Therefore, here, the exciting current is switched every time six pulses are counted. However, before that, each of the switching of the exciting current is performed at a timing of the preferable positional relationship between the rotor 14 and the magnetic poles of the stators 16a and 16b suitable for driving the carriage driving motor 1 smoothly and satisfactorily. When is turned on, the MPU 20 controls the initialization so that the value of the counter is set to 0 and the position of the rotor 14 is adjusted to a preferable position for switching the exciting current.

Here, for example, the switching of the exciting current is preferably performed when the center of each magnetic pole of the rotor 14 (the strongest point of magnetization) and the center of one of the magnetic poles of the stators 16a and 16b coincide, that is, when the driving torque is zero. The above initialization is performed as follows, for example.

That is, first, a current is applied to one of the coils 15a and 15b in the same direction for a predetermined time or more. Next, the rotor is slightly rotated by the excitation of the coil due to this energization, the center of each magnetic pole of the rotor 14 faces the center of each magnetic pole of the stator of the energized coil, and the counter value is set when the rotor 14 is stationary. Set to 0 to shut off the exciting current.

By such initialization, the correspondence between the count value of the switching timing of the exciting current and the position of the magnetic pole of the rotor 14 can be properly associated. That is, the time when the six pulses are counted and the time when the torque at which the centers of the magnetic poles match each other are 0 are matched. This correspondence is maintained unless the printer power is turned off after initialization.

The magnetic pole of the detection disk 17 of the encoder 25 and the rotor 14
The mechanical deviation of the position of the magnetic poles is not a big issue here. That is, here, the rotor 14 has 24 magnetic poles, while the detection disk 17 has 144 magnetic poles, and the encoder output pulse is 288 pulses per rotation.
The number of output pulses per pole of the rotor 14 is 12 pulses. The range of pulse shift due to the above-mentioned position shift is half the pulse interval, and the error range is ± 4.2% (= ± 1/24
X100%), and the shift in the switching timing of the exciting current corresponding to this is negligible. Therefore, the relative position of the rotor 14 and the disk 17 need not be adjusted, and the magnetic pole of the rotor 14, that is, the rotational angle position of the rotor 14 can be detected without adjustment.

Next, the control operation of the carriage drive motor 1 by the MPU 20 during recording will be described with reference to FIG. The description of the control operation of other mechanisms by the MPU 20 is omitted here.
Further, FIG. 4 shows a processing procedure of drive control of the carriage drive motor 1 by the MPU 20, and a control program corresponding thereto is stored in the ROM 21.

When the power of the printer is turned on, the MPU 20 first performs an initializing operation in step S1 of FIG. 4 to establish a correct correspondence between the position of the rotor 14 and the count value of the counter of the current switching circuit 24 described above.

Next, in step S2, it is confirmed whether or not the carriage 2 is at the home position at the left end in FIG. 1, and if not, the carriage drive motor 1 is driven in step S3 to move the carriage 2 to the home position. The position detection of whether or not the carriage 2 is at the home position is performed by, for example, an optical sensor including a light emitting diode and a phototransistor.

Next, in step S4, the MPU 20 determines the rotation speed and the rotation direction of the motor 1 according to the recording mode instructed by the host system (not shown), and determines the number of drive pulses of the carriage drive motor 1 from the number of prints in one line.

Then, a signal instructing the motor rotation speed is output to the motor speed control circuit 23, and the carriage drive motor 1 is started by driving the current switching circuit 24 in step S5. That is, the carriage 2 is started. At the same time as the carriage drive motor 1 is started, the MPU 20 starts counting the output pulses of the encoder 25.

Next, in step S6, the MPU 20 checks whether or not the carriage 2 has reached the print start position based on the count value of the output pulse of the encoder 25, and if the carriage 2 has reached the print start position, the recording head 4 is driven to start printing in step S7.

Next, in step S8, it is checked whether or not the carriage 2 has reached the print end position for one line based on the count value of the output pulse of the encoder 25, and if the carriage 2 has reached the print end position, the print operation of the recording head 4 is stopped in step S9. Finish printing the line. Then, in step S10, a stop signal is output to the current switching circuit 24, and the current switching circuit 24 short-circuits both ends of the coil of the carriage drive motor 1 in response to this signal to stop the carriage drive motor 1.

Next, in step S11, the MPU 20 checks whether or not all printing is completed depending on the presence / absence of the remaining amount of print data.

If all printing is completed, move to step S13,
The carriage drive motor 1 is driven to move the carriage 2 to the home position, and the process is completed.

If all the printing has not been completed and there is print data for the next line, the process proceeds to step S12, the carriage 2 is moved to the print start position for the next line by driving the carriage drive motor 1, and the process returns to step S7. The following processing is repeated.

When performing reciprocal printing, the print start position of the next line is the right end position of the print width of the next line. When the carriage drive motor 1 is rotated in the reverse direction to move the carriage 2 in the reverse direction (R direction in FIG. 1), the output pulse of the encoder 25 is subtracted and counted to detect the position of the carriage 2. is there.

According to the present embodiment as described above, the encoder as described above
By controlling the excitation current switching timing of the carriage drive motor 1 and the rotation speed of the motor in a closed loop control according to the output of 25, the excitation current is always switched at the optimum timing and the acceleration is sequentially and smoothly performed. The carriage drive motor 1 operates smoothly and satisfactorily. Therefore, the vibration of the carriage driving motor 1 is small, and the noise during the driving can be suppressed to a low level. Further, even when the carriage drive motor 1 is stopped, the carriage drive motor 1 can be smoothly and quickly stopped by the above-described stopping method, and noise at that time can be suppressed to a small level.

Further, since the carriage drive motor of this embodiment is a multi-pole stepping motor, a large torque can be obtained. That is, the maximum value T of the torque of the motor is NI (ampere turn) for the magnetomotive force of the coil, Φ (weber) for the magnetic flux generated from the rotor and the magnetic flux that links the coil, and p for the magnetic pole pair of the rotor.
Assuming that the proportional constant is k, a motor having many magnetic poles such as a step motor produces a large torque as represented by T = kpΦNI (Newton meter). Thus, a large torque can be obtained and the response speed is fast, and high speed recording can be performed using this.

As described above, according to the present embodiment, a high-speed serial printer with low noise can be realized by using the PM type stepping motor as a carriage drive motor by making it into a DC brushless motor without adjustment. DC for stepping motors
There is no problem of reliability due to contact life as in the case of a brush motor.

In the above description, the switching timing of the exciting current of the carriage drive motor 1 is controlled at the time when the torque becomes 0, but the invention is not limited to this. For example, a time slightly before the time when the torque becomes 0. But good. Further, the switching timing may not always be controlled to a predetermined timing, but may be controlled to a different timing depending on the situation such as acceleration, low speed traveling, and deceleration. The current switching circuit 24 is controlled by the MPU20.
It is sufficient to shift the count of the counter that switches the excitation current depending on the difference in the above situation.

Further, as described above, according to the control method of controlling the switching timing of the exciting current based on the count value of the output pulse of the encoder 25, switching between so-called 180 ° energization of the two-phase excitation system and so-called 90 ° energization of the one-phase excitation system, etc. Can also be easily done by the software of MPU20.

Second Embodiment By the way, in the above-described first embodiment, the carriage drive motor 1 is configured as a PM type step motor,
A hybrid type step motor may be constructed as shown in FIG. 5 as a second embodiment of the present invention. In this case as well, the detection disk 17 is similarly attached to the rotor shaft 13, the MR element substrate 18 is provided so as to face the disk 17, and the encoder 25 described above is configured. It is assumed that the excitation current switching timing and the rotation speed are closed-loop controlled.

However, in the case of the hybrid type, the number of magnetic poles of the rotor 14 is large,
The number of times the excitation current for one rotation is switched also increases. For example, assuming that the number of teeth of the magnetic pole of the rotor 14 is 100, the number of times the current is switched in one rotation is 200 in the two-phase excitation method. In this case, the encoder 25 is configured to output a signal of 800 pulses per one rotation of the rotor 14, for example, and the current switching circuit 24 switches the exciting current every time four pulses are counted.

By using the hybrid type step motor in the closed loop control as the carriage drive motor 1 in this manner, the same operation and effect as in the case of the first embodiment described above can be obtained, and by the hybrid type motor, the first step motor can be obtained. A higher output can be obtained than in the case of the embodiment.

Third Embodiment Next, FIGS. 6 and 7 (A) to (C) show the third embodiment of the present invention.
3 illustrates a structure of a carriage drive motor used in an embodiment.

In this embodiment, as shown in FIG. 6, a PM type step motor as the carriage driving motor 1 is provided with a detection disk 17 and an MR element substrate 18 as in the case of the first embodiment to form the encoder 25 described above. In addition, FIG. 7 (A)-
Hall elements 26a and 26b are provided in (C). Then, the rotation angle position and the magnetic pole position of the rotor 14 are detected by the encoder as in the case of the first embodiment, and also detected by the Hall elements 26a and 26b, and the carriage drive motor 1 is detected according to the output of the encoder. Is controlled, and the switching timing of the exciting current is controlled by the outputs of the Hall elements 26a and 26b.

Explaining the mounting structure of the Hall elements 26a and 26b, first, both elements are provided on the Hall element substrates 27a and 27b, respectively. Then, the Hall element substrates 27a and 27b are fixed to the annular plate-shaped Hall element positioning members 28a and 28b having the openings 29a and 29b for loosely fitting the rotor 14 in the center. Both positioning members 28a, 28b are provided with fan-shaped notches 30a, 30b for avoiding the Hall elements 26a, 26b. The two positioning members 28a, 28b are overlapped with each other so that the Hall elements 26a, 26b attached to each other fit into the respective notches 30a, 30b, and are joined as shown in FIG. 7 (B). And both positioning members 28a, 28b
Are coupled slidably in the circumferential direction with respect to each other within a range in which the Hall element substrates 27a, 27b do not contact the side edges of the respective cutouts 30a, 30b.

The assembly of the Hall element positioning members 28a, 28b is arranged below the stators 16a, 16b of FIG. 6 so that the rotor 14 can be loosely fitted in the openings 29a, 29b so as to be circumferentially adjusted in position. Attached to.

According to this structure, the Hall element positioning members 28a, 28
Since the position of b can be adjusted with respect to the stators 16a and 16b, the phases of the output signals of the Hall elements 26a and 26b with respect to the magnetic poles of the stators 16a and 16b can be finely adjusted. At the same time, since the Hall element positioning members 28a, 28b are slidable with respect to each other, the relative position between the Hall elements 26a, 26b can be adjusted, and the phase difference between the output signals of both Hall elements 26a, 26b can also be adjusted. Can be adjusted. By such adjustment, the magnetic pole position at the switching timing of the exciting current can be accurately detected with high accuracy.

In addition to the above structure, when a step motor is used as a drive source for other mechanisms of the printer, the noise reduction can be similarly reduced by controlling the excitation current switching timing and rotation speed in a closed loop with the same structure. And the operation speed can be increased.

[Effects of the Invention] As is apparent from the above description, according to the recording apparatus of the present invention, the switching of the excitation phase of the excitation current supplied to the coil of the step motor for driving the carriage is always performed at the optimum timing, and the step The motor can be driven smoothly, vibration during driving, starting and stopping can be suppressed, and noise can be reduced. Further, since there is no step out, a high frequency can be selected as the frequency of the drive pulse of the step motor, the step motor can be driven at high speed, and excellent effects such as high speed recording can be obtained.

[Brief description of drawings]

1 is a perspective view showing the structure of a carriage drive mechanism as a main part of the printer according to the first embodiment of the present invention, FIG. 2 is a sectional view showing the structure of the carriage drive motor in FIG. 1, and FIG. Block diagram showing the configuration of the drive control system of the motor,
FIG. 4 is a flow chart showing the control procedure of the carriage drive motor by the MPU in FIG. 3, and FIG. 5 is a sectional view showing the structure of the carriage drive motor as a hybrid type step motor used in the second embodiment of the present invention. FIG. 6 is a partially cutaway perspective view showing the structure of a carriage drive motor used in the third embodiment of the present invention, and FIG. 7 (A) is a hall element for attaching a hall element to the motor of FIG. The bottom view showing the structure of the positioning member, FIG. 7 (B) is a side view of the member,
FIG. 7 (C) is a top view of the same member. 1 ... Carriage drive motor 2 ... Carriage, 3a, 3b ... Pulley 4 ... Recording head 5a, 5b ... Guide shaft 6 ... Belt, 7 ... Recording paper 14 ... Rotor 15, 15a, 15b ... Coil 16, 16a, 16b ...... Stator 17 ...... Detection disk, 18 ...... MR element substrate 20 ...... MPU 23 ...... Motor speed control circuit 24 ...... Current switching circuit, 25 ...... Encoder 26a, 26b ...... Hall element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Yoshimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Bibliography Sho 61-7299 (JP, U)

Claims (1)

[Claims] 1. A carriage on which a recording head is mounted, a step motor for moving the carriage, a rotational angle position of a rotor of the step motor is detected, and a pulse signal is generated every rotation of the rotor by a predetermined angle. Detecting means for counting the pulse signals from the detecting means, detecting the position of the carriage according to the count value, and outputting a control signal for starting and stopping the carriage; A plurality of pulse signals, and switching means for controlling the excitation phase switching of the excitation current supplied to the coil of the step motor according to the count value, and the switching means is controlled by a start control signal from the control means. The special feature is that the excitation phase switching control of the excitation current is started and the excitation phase switching control of the excitation current is stopped by the stop control signal. To the recording device.