JP2003341166A - Shuttle control method of printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce vibration and noise when operation of a printer having a crank system shuttle mechanism comprising a stepping motor is started without requiring an expensive stepping motor and without lowering the reliability of the printer. <P>SOLUTION: In the printer having the crank system shuttle mechanism comprising a hammer bank mounting a plurality of print elements, and the stepping motor for reciprocating the hammer bank, a switching is made from 1-2 phase exciting system to 2 phase exciting system when the stepping motor is started. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shuttle control method for a printing apparatus having a crank type shuttle mechanism composed of a stepping motor.

[0002]

2. Description of the Related Art A shuttle mechanism section of a printing apparatus having a crank type shuttle mechanism composed of a stepping motor and capable of reciprocally moving a hammer bank having a plurality of printing elements (dot printing hammer, etc.) by the shuttle mechanism. An example will be described with reference to FIGS. 5 and 6.

A hammer bank 10 having a plurality of dot printing hammers (not shown) is supported by a guide shaft 12 via a linear bearing 11. Further, one ends of the two cranks 13 are respectively connected to the hammer bank 10 and the counter balancer 14, and the other ends thereof are connected to a stepping motor 20 which is a power source of reciprocating motion. Since the two cranks 13 are connected to the stepping motor 20 with a 180 ° phase shift, the hammer bank 10 and the counter balancer 14 reciprocate in opposite phases.

The rotation operation of the stepping motor 20 is controlled so as to operate on a predetermined angular velocity curve. The control is performed by the shuttle control circuit 3 that changes the drive cycle of the drive current supplied to the stepping motor 20.
0, the shuttle drive circuit 40 for supplying a current to the stepping motor 20. FIG. 4 shows an example of the angular velocity of the stepping motor 20 and the velocity waveform of the hammerbank 10. By operating the stepping motor 20 on a predetermined angular velocity curve, the hammer bank 10 connected by the crank 13 reciprocates in the velocity curve as shown in the drawing, and printing is performed in the course of the reciprocating operation. .

The printing paper is mounted so as to face the hammer bank 10 and is conveyed by paper feeding means (not shown). Then, in the process of reciprocating the hammer bank 10,
Printing is performed by driving the printing element toward the printing paper via an ink ribbon (not shown).

Next, FIG. 3 shows an example of the angular velocity waveform when the stepping motor 20 is started. When the stepping motor 20 is started, the stepping motor 20 is rotated at a low angular velocity capable of self-starting, and the time until the rotation of the stepping motor is stabilized,
It is common to operate at a constant speed. After the rotation of the stepping motor is stabilized by the constant speed operation, the acceleration operation, that is, the slow-up is performed to accelerate to the angular velocity during the printing operation.
After that, the hammer bank 10 is controlled to operate on the angular velocity curve during the printing operation, the hammer bank 10 reciprocates, and printing is performed in the course of the reciprocating operation.

[0007]

In the conventional shuttle control method, as shown in FIG. 3, since the excitation method is fixed, for example, in the case of the two-phase excitation method, vibration and noise are large at the time of starting. There was a problem. When the 1-2 phase excitation method is used to reduce vibration and noise at startup, the stepping motor output torque is smaller than that of the 2-phase excitation method, so that the stepping motor is easily out of step. Therefore, in order to improve the reliability, an expensive stepping motor with a large generated torque is used. Therefore, it has been a factor of increasing the cost of the device.

The present invention relates to a printing apparatus having a crank type shuttle mechanism composed of a stepping motor, without using an expensive stepping motor, and without lowering the reliability of the apparatus, vibration and noise at the time of start-up. It is an issue to reduce.

[0009]

[Means for Solving the Problems] The above-mentioned problem is that when the stepping motor is started, the excitation method is changed from 1-2 phase excitation method to 2
It is achieved by switching to the phase excitation method.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Since the structure of the shuttle mechanism section is the same as that of the prior art, the description thereof will be omitted. FIG. 1 shows an example of an angular velocity waveform when starting the stepping motor in the present invention, and FIG. 2 shows an example of an excitation pattern when switching the excitation method. An embodiment of control for switching the excitation method of the stepping motor according to the present invention will be described below with reference to FIGS. 1 and 2.

Similar to the conventional shuttle control method, when the stepping motor is started, the stepping motor is rotated at a low angular velocity capable of self-starting. In the present invention, the vibration at startup,
In order to suppress noise, it starts by the 1-2 phase excitation method.
Next, the constant speed operation is performed until the rotation of the stepping motor stabilizes. Since the time until the rotation of the stepping motor stabilizes varies depending on the system of the shuttle mechanism unit, an arbitrary time is set according to the system. Further, in a system in which the time until the rotation of the stepping motor stabilizes is short, the constant speed operation may not be performed, and the acceleration operation, that is, the slow-up may be performed immediately after the startup.

By starting by the 1-2 phase excitation method, vibration and noise at the time of starting are suppressed, and then switching to the two phase excitation method is performed. By switching to the 2-phase excitation method,
The operation mode in which the output torque of the stepping motor is large is entered, and the stable operation of the stepping motor becomes possible.
The timing for switching from the 1-2 phase excitation method to the two phase excitation method is different depending on the system of the shuttle mechanism unit, so an arbitrary timing is set according to the system. For example, there are cases where vibration and noise can be sufficiently suppressed even when switching to the two-phase excitation method during self-starting constant speed rotation. In this case, as shown in FIG. 1A, the driving method is switched to the two-phase excitation during the self-starting constant speed rotation.

Further, there are two driving methods during the self-starting constant speed rotation.
If the noise and vibration cannot be sufficiently suppressed after switching to the phase excitation method, self-starting is started by the 1-2 phase excitation method, and acceleration operation after constant speed rotation of self-starting, that is, start of slow-up Sometimes it switches to the two-phase excitation method. Furthermore, 2 during or after the slow-up
You may switch to a phase excitation system. At the start of slow-up in (B) of FIG. 1, in the middle of slow-up in (C),
After slowing up to (D), at each point 1-
The switching timing when the excitation method is changed from the two-phase excitation method to the two-phase excitation method is shown. When a plurality of print modes are provided, the excitation method switching timing may be changed according to the print modes.

As described above, the excitation method is changed from the 1-2 phase excitation method to 2
Although the timing for changing to the phase excitation method has been shown, the timing may be selected at a position where vibration and noise can be suppressed most in the shuttle mechanism system.

An example of the excitation pattern when switching the excitation method is as shown in FIG. The stepping motor is driven by the 1-2 phase excitation method until the switching timing, and the stepping motor is driven by the two phase excitation method after the switching timing. FIG. 2 shows a case where the pattern for exciting the A phase is driven by the 1-2 phase excitation method, and the pattern for exciting the AB phase is switched to the two phase excitation method.

By using the shuttle control method of the present invention, it is possible to start by the 1-2 phase excitation method and reduce the vibration and noise generated at the time of start, and further switch to the two phase excitation method after the start. As a result, the operation mode in which the output torque of the stepping motor is large is entered, and the stable operation of the stepping motor becomes possible.

[0017]

According to the present invention, it is possible to reduce vibration and noise at the time of starting without using an expensive stepping motor and without lowering the reliability of the equipment.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an example of an angular velocity waveform when starting a stepping motor in the present invention.

FIG. 2 is a conceptual diagram showing an example of an excitation pattern when switching an excitation method in the present invention.

FIG. 3 is a conceptual diagram showing an angular velocity when a stepping motor is activated.

FIG. 4 is a conceptual diagram showing a stepping motor angular velocity and a hammerbank velocity waveform.

FIG. 5 is a schematic side view showing an example of a crank type shuttle mechanism unit using a stepping motor.

FIG. 6 is a schematic top view showing an example of a crank type shuttle mechanism section using a stepping motor.

[Explanation of symbols]

10 is a hammer bank, 11 is a linear bearing, 12 is a guide shaft, 13 is a crank, 14 is a counter balancer,
20 is a stepping motor, 30 is a shuttle control circuit,
40 is a shuttle drive circuit.

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Claims (6)

[Claims] 1. A printer having a crank-type shuttle mechanism composed of a hammer bank having a plurality of printing elements mounted thereon and a stepping motor for reciprocating the hammer bank.
A shuttle control method for a printing apparatus, wherein the excitation system is switched from the 1-2 phase excitation system to the two phase excitation system. 2. The shuttle control method for a printing apparatus according to claim 1, wherein the excitation system is switched during the self-starting constant speed rotation of the stepping motor. 3. The shuttle control method for a printing apparatus according to claim 1, wherein the excitation method is switched at the start of slow-up at the time of starting the stepping motor. 4. A method of controlling a shuttle of a printing apparatus according to claim 1, wherein the excitation method is switched during a slow-up when the stepping motor is started. 5. The shuttle control method for a printing apparatus according to claim 1, wherein the excitation method is switched after the slow-up at the time of starting the stepping motor is completed. 6. The printing apparatus comprises a plurality of printing modes, that is, a plurality of types of angular velocity patterns of the stepping motor, a plurality of timings for switching the excitation method, and a timing for switching the excitation method is changed according to the printing mode. The method according to claim 2, 3, 4, or 5
A method for controlling a shuttle of a printing apparatus described.