JP2003145874A - Shuttle control method of printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a reference position of a stepping motor driving signal without using a rotary sensor and execute a feedback control for the stepping motor driving signal by calculating a phase angle difference of a rotor and a stator of a stepping motor without using a rotary sensor in a printer having a clank system shuttle mechanism constituted of the stepping motor. SOLUTION: The reference position of the stepping motor driving signal is generated by a linear sensor signal. Moreover, the phase angle difference of the rotor and the stator of the stepping motor can be calculated by the linear sensor signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 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. Two
Since each crank 13 is 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.

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. 4 shows an example of the angular velocity of the stepping motor 20 and the velocity waveform of the hammer bank 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 prints during the reciprocating operation. Is carried out.

As a conventional technique, a linear sensor 36 is attached to the hammer bank 10 to detect a print position, and a rotary sensor 35 is attached to a rotary shaft of the stepping motor 20 to generate a reference position of a stepping motor drive signal.
Is attached.

The reference position of the stepping motor drive signal is generated in order to synchronize the position of the hammer bank 10 with the signal for driving the stepping motor 20 so that the hammer bank 10 reciprocates in the speed curve shown in FIG. To implement. Specifically, when the hammer bank reaches a specific position (for example, the right end of the hammer bank reciprocating motion), the reference position signal is output from the rotary sensor 35 and is used as the start position of the stepping motor drive signal. Therefore, the relative position of the rotary sensor 35 and the hammer bank 10 is generally adjusted during assembly.

In the prior art, it is known that the rotary sensor 35 is used to calculate the angular difference between the phase angle of the rotor of the stepping motor and the phase angle of the stator, and the feedback control of the stepping motor drive signal is performed. There is.

[0011]

In a conventional crank type shuttle mechanism composed of a stepping motor, a linear sensor for detecting the position of a hammer bank and a reference position of a stepping motor drive signal are generated. Since it was necessary to provide two types of sensors, that is, a rotary sensor, it was a factor of increasing the cost of the device.
In addition, it is possible to convert the hammer bank position, that is, the printing position, by using the rotary sensor without installing the linear sensor, but it is possible to convert the position of the crank mechanism part such as backlash to ensure the required print quality. Detection accuracy cannot be obtained. Therefore, generally, both the linear sensor and the rotary sensor are attached.

An object of the present invention is to generate a reference position of a stepping motor drive signal in a printing apparatus having a crank type shuttle mechanism composed of a stepping motor without using a rotary sensor. Another object of the present invention is to calculate the angle difference between the phase angle of the rotor of the stepping motor and the phase angle of the stator without using the rotary sensor, and to perform the feedback control of the stepping motor drive signal.

[0013]

[Means for Solving the Problems] In order to solve the above problems,
The present invention has a crank type shuttle mechanism composed of a hammer bank on which a plurality of printing elements are mounted and a stepping motor that reciprocates the hammer bank, and a linear sensor for detecting the position of the hammer bank. According to another aspect of the present invention, the linear sensor signal is used to generate a reference position of the phase excitation drive signal of the stepping motor.

Further, the linear sensor signal is used to calculate the angle difference between the phase angle of the rotor of the stepping motor and the phase angle of the stator, and feedback control of the phase excitation drive signal of the stepping motor is performed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The configuration of the shuttle mechanism section is the same as that of the prior art, and therefore will be omitted.

An example of control for generating the reference position of the drive signal of the stepping motor in the present invention will be described with reference to FIGS. 1 and 3.

When the stepping motor is started, a driving signal which rotates at a low speed capable of self-starting is input. By activating the stepping motor, the hammer bank starts reciprocating motion, and the waveform is output from the linear sensor.

FIG. 3 shows an example of the output waveform of the linear sensor and an example of the stepping motor drive signal.

As shown in FIG. 3, 2 with a 90 ° phase difference
The linear sensor of the channel (A phase, B phase) is used so that the movement direction of the hammer bank can be detected. At this time, the control process (interrupt process) is executed at the rising or falling edge of the A phase signal when the B phase signal is "L". Phase excitation No. when performing linear sensor interrupt processing during self-starting Is stored in memory. Phase excitation No. Is the total number of excitations after starting self-starting.

When the inversion of the hammer bank is detected by the linear sensor, the phase excitation No. Is stopped and the calculation for generating the reference position is performed. Here, from the start of self-starting until the stable operation of the hammer bank, for example,
Reversal is not detected until the stepping motor makes one revolution.

FIG. 1 shows a flow chart for generating the reference position of the drive signal of the stepping motor in the present invention.

In FIG. 1, the stepping motor has a phase excitation 40.
An example is the case of making one lap at 0 times.

The operation for generating the reference position is the phase excitation No. when the interrupt processing of the linear sensor before and after the inversion detection is executed. The sum of is halved. That is, the phase excitation N that was excited at the time of reversal
o. Is calculated and used as the reference position of the stepping motor drive signal.

The example shown in FIG. 3 will be described.

Each time the linear sensor interrupt processing occurs, the phase excitation No. Is stored in memory. 5 in the example of FIG.
It is stored in the order of 16, 517, 518. Phase excitation No.
After storing 520, the hammer bank is reversed, and the reference position is calculated by the linear sensor interrupt processing after the reversal.
That is, (b) 524 acquired at the time of interrupt processing is added to (a) 520 stored in the memory, divided by 2, and the phase excitation No. 522 is calculated. Phase excitation No. obtained by adding 400 to the reference position 522. That is, the drive profile is started from the reverse position after one round. Until then, self-starting is continued.

In the case of this example, the case where the reversal position is set as the reference position of the drive signal is shown, but an arbitrary position of the reciprocating motion of the hammer bank, for example, the center point of the reciprocating motion of the hammer bank may be set as the reference position.

Next, FIG. 2 shows a flow chart of the feedback control of the stepping motor drive signal in the present invention.

An example of performing feedback control of the stepping motor drive signal by calculating the angle difference between the phase angle of the rotor of the stepping motor and the phase angle of the stator using the linear sensor signal will be described.

As in the case of calculating the reference position of the drive signal at the hammer bank inversion position, the excitation phase excited at the hammer bank inversion position is detected by the linear sensor signal. If there is no phase difference between the rotor and stator,
The excitation phase that is actually excited at the reverse position and the excitation phase that should be excited at the reference position, that is, the excitation phase that should be excited at the reverse position match. When the excitation phase excited at the reverse position is different from the excitation phase to be excited at the reference position, the phase difference is the angular difference between the phase angles of the rotor and the stator. Therefore, when the phase difference exceeds a specific range, feedback control of the stepping motor drive signal is performed.

For example, if the rotor lags the stator, the length of the stator drive signal is extended until the rotor catches up. If the rotor leads the stator, the stator drive signal is advanced to the excitation phase of the rotor.
By performing the above feedback control, it is possible to prevent step-out. Here, the case where the inversion position of the hammer bank is used as the reference position of the drive signal is taken as an example, but like the case of calculating the reference position, any position of the reciprocating motion of the hammer bank, for example, the center of the reciprocating motion of the hammer bank Feedback may be performed using the point as the reference position.

[0031]

In the printing apparatus having the crank type shuttle mechanism composed of the stepping motor, the rotary sensor can be omitted and the adjustment work can be omitted by implementing the control method according to the present invention. It is possible to configure the mechanism section at low cost. Further, the number of parts can be reduced and the adjustment work is not required, so that the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a flowchart for generating a reference position of a drive signal for a stepping motor according to the present invention.

FIG. 2 is a flowchart of feedback control of a stepping motor drive signal according to the present invention.

FIG. 3 shows an output waveform example of a linear sensor and a stepping motor drive signal example.

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

FIG. 5 is a schematic side view showing an example of a crank type shuttle mechanism section 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,
Reference numeral 35 is a rotary sensor, 36 is a linear sensor, and 40 is a shuttle drive circuit.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masafumi Hiratsuka             1060 Takeda Stock Association, Hitachinaka City, Ibaraki Prefecture             Hitachi Koki Information Technology             -In F-term (reference) 2C480 CA01 CA43 CA44 CA57 CB35                       EA22 EA30

Claims (2)

[Claims] 1. A linear sensor for detecting the position of the hammer bank, which has 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, comprising: using a linear sensor signal to generate a reference position of a phase excitation drive signal of the stepping motor in a printing apparatus provided. 2. A shuttle control method for a printing apparatus according to claim 1, wherein the linear sensor signal is used to calculate an angle difference between a phase angle of a rotor of a stepping motor and a phase angle of a stator of the stepping motor. A shuttle control method for a printing apparatus, wherein feedback control of an excitation drive signal is performed.