JP2006198949A - Shuttle control method for printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent decrease in printing speed and maintain the normal reciprocating motion of the hammer bank, by preventing a speed from greatly decreasing in a constant-speed section, when a load on a hammer bank is rapidly increased, in a linear motor shuttle mechanism which is equipped with an energizing means for the inversion of the hammer bank. <P>SOLUTION: When an abnormal decrease in the speed is detected in the constant-speed section of the hammer bank, a driving current, which makes a thrust occur in the direction of acceleration, is fed to an inversion coil in the first half part of the constant-speed section, and a driving current, which makes a thrust occur in a speed-increasing direction, is fed to the inversion coil from before reaching an energizing section, on which a repulsive force from an inversion energizing means acts, in the second half part of the constant-speed section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing apparatus having a linear motor type shuttle mechanism, and more particularly to reciprocal movement control of a linear motor shuttle mechanism having a reversal urging means for urging reversal of reciprocal movement. .

  In a printing device that has a linear motor type shuttle mechanism and reciprocates a hammer bank equipped with a plurality of printing elements (dot printing hammers, etc.) with this shuttle mechanism, in order to improve the printing speed, when the hammer bank is reversed A shuttle mechanism having a reverse biasing means using a repulsive force such as a spring has been developed.

  FIG. 2 shows an example of the configuration of a linear motor type shuttle mechanism provided with a reverse biasing means.

  The hammer bank 10 on which a plurality of printing elements are mounted is supported by the linear motion bearing 12 and reciprocates on the guide shaft 11. The linear motor unit 20, which is a power source for reciprocating operation, includes at least a coil 21 and a magnet 24, and the coil 21 generally includes an inversion coil 22 and a constant velocity coil 23. The hammer bank 10 and the coil 21 are connected to at least one timing belt 31, and a shuttle operation is possible by the power from the linear motor unit 20 by the reversing mechanism unit 30 constituted by at least one pair of supported timing pulleys 32. It is configured as follows.

  Further, at both ends of the hammer bank 10 or the coil 21, reverse biasing means (for example, springs) 40 are disposed at positions for biasing the reverse. The reverse biasing means 40 is not limited to a spring, and may be a means using the same-polar repulsion of a magnet.

  In the reciprocating reciprocation of the hammer bank 10 and the coil 21, the position detection sensor 50 attached to the movable part calculates the position and reciprocating speed of the hammer bank 10 and operates on a predetermined reciprocating speed curve. . The control is performed by a shuttle control circuit 60 that changes the value of the current supplied to the coil 21 and a shuttle drive circuit 70 that supplies a current to the coil 21.

  The printing paper is mounted facing the hammer bank and is conveyed by a paper feeding means (not shown). In the course of the reciprocating operation of the hammer bank 10, printing is performed by driving the printing element toward the printing paper via the ink ribbon.

  Next, the hammer bank speed waveform and coil drive current of the linear motor shuttle mechanism will be described with reference to FIG. In FIG. 3, the shuttle operation of the hammer bank is divided into an inversion section and a constant speed section as shown in the speed waveform. In the reversal section, the reversing coil 22 is energized to perform deceleration control and acceleration control, and in the constant speed section, the constant speed coil 23 is energized to perform constant speed control of constant speed movement.

  On the other hand, printing apparatuses having several kinds of printing speed patterns have been developed to meet various printing needs. In such a printing apparatus, in the rear portion of the shuttle machine provided with the reverse biasing means, the distance of the biasing section is constant regardless of the printing speed setting in order to simplify the structure. That is, for example, in the case of a printing apparatus having three types of printing speeds, that is, a normal printing speed, a high-speed printing speed, and a low-speed printing speed, the urging section of the inverting urging means in the inverting section has the greatest force for acceleration / deceleration. Is matched to the inversion section when setting the high-speed printing speed. Therefore, as shown in FIG. 4, when the low printing speed is set, the urging section extends to the constant speed section. The left side reverse biasing section is defined as position X1 to left side reverse position XL to position X1, and the right side reverse biasing section is defined as position X2 to right side reverse position XR to position X2.

  When a section where the biasing force by the reverse biasing means is applied (hereinafter referred to as a biasing section) is applied to the constant speed section, it occurs in a direction opposite to the biasing force or repulsive force in order to stabilize the speed of the constant speed section. 2. Description of the Related Art A printing device having a control for energizing a coil with a drive current is known (see, for example, Patent Document 1). The coil drive current in FIG. 3 is an example of the drive current by the control. The left biasing section by the reverse biasing means is defined as position X1 to the left reverse position XL to position X1, and the right biasing section is defined as position X2 to the right reverse position XR to position X2. Among the urging sections, a repulsive force acts on the deceleration section side and a urging force acts on the acceleration section side with a reversal position (intersection with the horizontal axis of the graph) as a boundary.

  In order to increase the speed stability of the constant speed section, inversion in the second half of the acceleration section and the first half of the constant speed section (position accelerated to speed V1 to position X1, position accelerated to speed -V1 to position X2) Apply a suppression current to the coil. As a result, the urging force can be canceled, and it is possible to prevent the speed in the first half of the constant velocity section from being exceeded.

  On the other hand, in the latter half of the constant speed section (position X2 to position X3, position X1 to position X0), a speed increasing current is supplied to the reversing coil. As a result, the repulsive force can be canceled out, and the speed reduction in the latter half of the constant velocity section can be prevented.

  As described above, since the reciprocating motion of the hammer bank is controlled so as to operate on a predetermined speed curve, it is possible to follow a slight load fluctuation to the hammer bank with normal feedback control, When the load on the hammer bank is suddenly increased (for example, when printing is performed near the crease of the printing paper), the speed of the constant speed section is significantly reduced. 2. Description of the Related Art Conventionally, a printing apparatus having a control (hereinafter referred to as an overload return control) that prevents a significant speed drop in a constant speed section when a load on a hammer bank is suddenly increased has been developed (for example, Patent Documents). 2).

  FIG. 5 shows an example of overload recovery control in the prior art. When the load on the hammer bank increases abruptly, the thrust of the constant speed movement of the hammer bank is insufficient, and the speed of the constant speed section is greatly reduced. In the overload recovery control, the speed of the hammer bank is monitored from a predetermined position X4 in the first half of the constant speed section, as shown in the speed waveform, in order to cope with a sudden load increase on the hammer bank, and the speed decrease detection speed V2 When the following is detected, the constant speed coil drive current is increased, and a significant speed reduction in the constant speed section is prevented. Further, the speed increasing current is increased in the section where the repulsive force from the reverse biasing means in the latter half of the constant speed section is applied, and a significant speed reduction is prevented even in the section where the repulsive force works.

JP-A-11-170652

JP 2000-094775 A

  As shown in the prior art, by using the overload return control, when the load on the hammer bank is suddenly increased, it is possible to prevent a significant speed reduction in the constant speed section. However, due to the time delay of the constant-speed coil generation thrust, it is difficult to return to the normal constant speed as shown in the operation waveform in the conventional overload return control of FIG. Therefore, it enters into the energizing section in which the repulsive force from the reverse energizing means works in a state where the constant speed is reduced as compared with the normal operation. In the overload recovery control in the prior art, the acceleration current is increased to prevent a significant decrease in speed even in the section where the repulsive force from the reverse biasing means works, but the bias is applied with the constant speed reduced. Since entering the section, it is difficult to return to the same speed as during normal operation, and there is a problem that the hammer bank cannot be operated to a predetermined reciprocating amplitude. Moreover, since the speed of the constant speed section decreased over a long section, a decrease in printing speed was observed.

  The present invention provides a shuttle mechanism equipped with a reverse biasing means, which prevents a decrease in the speed of the constant speed section when the load on the hammer bank is suddenly increased, and a repulsive force from the reverse biasing means in the latter half of the constant speed section acts. It is an object of the present invention to reach the section in which the speed is restored to the same speed as in normal operation, to maintain normal reciprocation of the hammer bank, and to prevent a decrease in printing speed.

  The problem is that when a speed abnormality drop in the constant speed section is detected, a driving current (hereinafter referred to as an overload return acceleration current) that generates thrust in the acceleration direction in the first half of the constant speed section is supplied to the reversing coil, In the latter half of the constant velocity section, the drive current that generates thrust in the acceleration direction (hereinafter referred to as overload recovery acceleration current) is applied to the reversing coil before reaching the energizing section where the repulsive force from the reversing biasing means works. It is solved by energizing.

  According to the present invention, in the linear motor shuttle mechanism equipped with the biasing means at the time of reversing the hammer bank, when the load on the hammer bank is suddenly increased, a significant speed decrease in the constant speed section is prevented, and the normal of the hammer bank is prevented. In addition to maintaining a reciprocating motion, it is possible to prevent a decrease in printing speed.

  The purpose of maintaining a normal reciprocating motion of the hammer bank and preventing a decrease in printing speed during a sudden increase in load on the hammer bank is to detect a decrease in abnormal speed in the constant speed section. In the first half, the overload return acceleration current is supplied to the reversing coil, and in the constant speed second half, the overload return acceleration current is supplied to the reversing coil before reaching the energizing section where the repulsive force from the reversing biasing means works. Realized by feedback control.

  Since the structure of the shuttle mechanism is the same as that of the prior art, the description thereof is omitted.

  FIG. 1 shows a hammer bank speed waveform and coil drive current during overload recovery control in the present invention.

  The speed of the hammer bank is monitored from the position X4 in the first half of the constant velocity section, and the overload return control is started when the speed drops to V2 or less due to a sudden load increase on the hammer bank. In the case of having a plurality of print modes, a plurality of positions X4 and speeds V2 may be provided according to the print mode. When an abnormal speed drop is detected in the first half of the constant speed section, an overload return acceleration current is applied to the reverse coil as shown by the reverse coil drive current in FIG. 1 to prevent a significant speed drop in the constant speed section. . When the hammer bank approaches the center of the amplitude of the reciprocating motion, the energization to the reversing coil is temporarily stopped, and the current in the direction opposite to the overload recovery acceleration current from the point where the hammer bank exceeds the center of the amplitude, that is, the excess Energize the reverse coil with the load recovery acceleration current. This is because, when an acceleration current is applied due to the characteristics of the reversal coil, a thrust in the direction of the center of the amplitude is generated, so a drive current that generates a thrust in the direction of the outside of the amplitude from the point beyond the center, that is, acceleration. A current in the opposite direction to the current is applied to the reversing coil. Similar to the overload recovery acceleration current, the overload recovery acceleration current is shown as the inversion coil drive current in FIG.

  On the other hand, in the first half of the constant speed section, it does not drop below V2 of the detected speed, but when it falls to V2 or below for the first time in the second half of the constant speed section, overload return acceleration current is not energized and overload recovery Energize acceleration current.

  According to the present invention, even when the load on the hammer bank is suddenly increased, it is possible to return to the normal speed at the normal time, and normal operation is performed in the section where the repulsive force from the reverse biasing means in the latter half of the constant speed section acts. It is possible to reach the same speed as the time and maintain the normal reciprocating movement of the hammer bank and to prevent the printing speed from being lowered.

The figure which shows the speed waveform and coil drive current waveform of the hammer bank in this invention. Example 1 The schematic side view which shows an example of the shuttle mechanism using a linear motor. The figure which shows the velocity waveform and coil drive current waveform of a hammer bank. The figure which shows the energizing area according to printing speed setting, and a coil drive current waveform. The figure which shows the speed waveform and coil drive current waveform of a hammer bank in a prior art.

Explanation of symbols

10 is a hammer bank, 11 is a guide shaft, 12 is a linear bearing, 20 is a linear motor unit, 21 is a coil, 22 is a reversing coil, 23 is a constant velocity coil, 24 is a magnet, 30 is a reversing mechanism, and 31 is timing. A belt, 32 is a timing pulley, 50 is a position detection sensor, 60 is a shuttle control circuit, and 70 is a shuttle drive circuit.

Claims (4)

  A hammer bank having a plurality of printing elements, and at least a magnet and a coil, and reciprocating the hammer bank by energizing a drive current to the coil, and near the both ends of the amplitude of the hammer bank. In a printing apparatus having a linear motor type shuttle mechanism with a reverse biasing means that biases the reversal of the reciprocating movement of the hammer bank, it is reversed in the first half of the constant speed section by detecting a decrease in speed abnormality in the constant speed section. A shuttle control method for a printing apparatus, wherein a drive current that generates thrust in an acceleration direction is applied to a drive coil.   A hammer bank having a plurality of printing elements, and at least a magnet and a coil, and reciprocating the hammer bank by energizing a drive current to the coil, and near the both ends of the amplitude of the hammer bank. In a printing apparatus having a linear motor type shuttle mechanism with a reverse biasing means that biases the reversal of the reciprocating movement of the hammer bank, it is reversed in the second half of the constant speed section by detecting a decrease in speed in the constant speed section. A shuttle control method for a printing apparatus, characterized in that a driving current for generating thrust in a speed increasing direction is applied to a driving coil.   3. The printing according to claim 1, wherein the printing apparatus has a plurality of printing modes, and has a plurality of types of setting values of detection speeds of abnormal speed reduction in a constant speed section according to the printing modes. Device shuttle control method. The shuttle of a printing apparatus according to claim 1 or 2, wherein the printing apparatus has a plurality of printing modes, and has a plurality of types of detection start positions of a speed drop abnormality in a constant speed section according to the printing modes. Control method.

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