JPH0548193B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to drive control of a printing head such as a shuttle head, and more particularly to a head movement speed control method for stopping the shuttle head during retraction of a platen.

(2) Prior Art and Problems Some printing devices have a shuttle head equipped with a printing pin and a platen placed opposite each other, and perform printing while passing a recording medium such as paper between the two members. Conventional examples of such printing devices include those shown in FIGS. 1 and 2, for example. This printing device consists of a shuttle head 2 that is slidably supported by a guide shaft 3 attached to the device body 1, a platen 4 disposed below the shuttle head 2, and a shuttle head 2 that extends in the longitudinal direction of the guide shaft 3. It includes a screw gear 11 for reciprocating movement, a space motor 9 that supplies driving force to the shuttle head via the screw gear 11, a medium conveyance table 19 on which the recording medium is placed, and a feed roller 20 that feeds the recording medium to the printing section. Become. An eccentric cam 6 is attached to the shaft 5 of the screw gear 11 to move the platen 4 forward and backward relative to the shuttle head 2. screw gear 1
1 and the platen 4, the platen 4 is suspended and supported by a spring 7, while the platen 4 is moved downward against the action of the spring 7.
A plurality of printing pins a are attached to the side of the platen 4 of the shuttle head 2 in a line, while a table surface 4 is attached to the side of the shuttle head 2 of the platen 4.
a is formed. Sensor parts 15 and 16 are provided on the outer peripheral surface of the screw gear 11 to determine the print position and the platen position, while a print position detection sensor 17 and a platen position detection sensor 17 are provided in the parts of the main body 1 corresponding to the sensor parts 15 and 16, respectively. Position detection sensor 18
is installed. Light, magnets, etc. are used for these sensors. The recording medium is conveyed by a paper feed motor 21 and gear mechanisms 22, 23, and 23 installed between the paper feed motor 21 and the roller shaft.
It is carried out by 24. Note that reference numeral 13 is a speed detector, and reference numeral 14 is a cable that supplies power to the space motor 9.

When the printing device having such a configuration is operated, the shuttle head 2 reciprocates in the left-right direction according to the period of one character as shown in FIG. The time to do this is return trip B. On the other hand, the platen 4 moves up and down in response to the reciprocating movement of the shuttle head 2, and as shown in FIG. During the movement, the platen 4 assumes a lowered position C2, that is, a retracted position. The rise and fall of the platen 4 is detected by the platen position detection sensor 18, and while the shuttle head 2 is moving on the outward path F, the print pin 2a is moved at a predetermined timing according to the output C1 of the print position detection sensor 17. Power is applied at (FIG. 3c and d). When it is desired to suck in or eject a recording medium, the power supply to the space motor 9 for moving the guide shaft 2 is stopped, and the shuttle head 2 is moved to the evacuation area C2 of the platen 4.
It is designed to stop inside the machine and feed the paper.

However, in such a conventional head movement speed control method, the current supply to the space motor 9 is cut off when the shuttle head 2 is at a specific position during its reciprocating stroke. Therefore, due to the inertial force of the shuttle head 2 during high-speed printing and changes in friction between members until it stops naturally, the stop position of the shuttle head 2 is not determined within a predetermined range, and sometimes when the platen 4 is raised, There was also a situation where shaft 2 stopped.

(3) Purpose of the Invention The present invention was made in view of the conventional problems as described above, and its purpose is to provide head movement control that can stop the shuttle head while the platen is retracting when sucking or ejecting a recording medium. The object of the present invention is to solve the above-mentioned conventional problems by providing a method.

(4) Structure of the Invention In order to achieve the above object, the present invention includes a print head that reciprocates in the longitudinal direction of a guide shaft, a drive motor that moves the print head in the longitudinal direction of the guide shaft, and a drive motor that increases the speed of the drive motor. A motor speed control section that controls the
a motor driver that conducts a drive current based on the determination of the motor speed control section; a platen that is provided opposite to the print head and moves forward and backward with respect to the print head in conjunction with the reciprocating movement of the print head; In the printing apparatus, the timing control unit determines whether to print or feed the paper based on the position, platen position, and recording medium conveyance preparation state. The driver lowers the drive current value, reduces the moving speed of the print head by a predetermined percentage, causes the print head to perform one cycle of pseudo reciprocating movement, and adjusts the forward and backward positions of the platen in conjunction with this reciprocating movement. causing the timing control unit to monitor, and based on the monitoring result, the timing control unit issues a current cutoff instruction to cut off the drive current from the motor driver;
The gist of the present invention is that the print head is stopped while the platen is in a retracted area.

(5) Embodiments of the Invention Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 4 and 5 are block diagrams showing the configurations of a control system and a space drive system, respectively, for carrying out the head movement speed control method of the present invention. Fourth
In the figure, the control system includes a motor start signal from the outside,
a motor spade control unit 30 that determines the speed of the space motor 9 in response to a motor correction signal and a speed designation signal; a space motor driver 31 that conducts current to the space motor 9 based on the determination by the motor speed control unit;
It consists of a space motor 9 and a speed detector 13. The output from the speed detector 13 is fed back to the motor speed control section 30.
Used to adjust the speed of space motors.

Further, in FIG. 5, the space drive system receives a platen position detection sensor 18, a printing position detection sensor 17, output signals from these detection sensors 17 and 18, and a recording medium conveyance preparation signal, and determines whether to print or not. the paper feed motor 21, the paper feed motor drive 33 that drives the paper feed motor 21 based on the output signal from the timing control unit 32 and the recording medium transport signal, and the print command signal. a print character buffer shape generating section 34 which receives a print timing signal and extracts a character to be printed; a print control section 35 which receives a print timing signal from a print position detection sensor 17 and controls a print operation; and a print pin magnet 37.
and a print pin magnet driver 36 that conducts current to the print pin magnet 37 based on the print pin drive signal output from the print control section 35.

FIG. 6 shows the timing when normal printing is performed using this configuration. In this diagram,
First, when the platen position detection sensor 18 (output signal a) detects the rise of the platen 4 (Tu period), the paper feed motor drive permission signal c from the timing control section 32 is turned off, and conveyance of the recording medium is prohibited. (Transportation status signal d). Next, when the shuttle head 2 enters the reciprocating printing area, the printing timing signal b is output from the printing position detection sensor 17, and at the same time, the medium conveyance signal d is turned off and the recording medium is stopped. Then, the print control section 3
A printing pin drive signal e is outputted from 5, a current is conducted to the printing pin magnet 37, and printing is performed on the recording medium during the P period. Print timing signal b
When the generation of is completed, the print drive signal e also turns off, and the medium conveyance signal d turns on. Then, after a certain period of time has passed (indicates within the Td period) after the platen position detection sensor 18 detects the descent of the platen 4, and the platen 4 has been sufficiently lowered, the paper feed motor drive permission signal c is turned on from the timing control section 32. Then, the paper feed motor driver 33 outputs the paper feed motor drive signal f. As a result, the recording medium is fed by a predetermined pitch and line feed CR of the print line is performed.

Next, FIG. 7 shows the timing when starting the medium conveyance operation from the normal printing state. In this figure, when the final printing stroke of the normal printing operation is completed, the shuttle head 2 is caused to perform one cycle of pseudo reciprocating motion while the speed of the shuttle head 2 is reduced (period D). Then, while the shuttle head 2 is moving back and forth, the print position detection sensor 17
The phase of the eccentric cam is detected by counting the number of print timing signals b output by the controller 10, and when a predetermined count number n is reached (period D'), the drive of the space motor 9 is turned off. As a result, the shuttle head 2 performs an inertial movement, enters the retraction area of the platen 4, and stops after a certain period of time has elapsed since the platen 4 entered the retraction state (S). This stoppage of the shuttle head 2 is detected when the position of the platen 4 does not change for a certain period of time. After confirming that the shuttle head 2 has stopped while the platen 4 is in the retracted state, a continuous paper feed motor drive signal is output from the paper feed motor driver 33, and the recording medium is continuously conveyed. Note that when the drive of the space motor 9 is turned off, a braking action may be applied to the shuttle head 2 by, for example, operating a power generating brake as the case may be.

(6) Effects of the Invention As explained above, according to the present invention, when performing the suction and ejection operation of a recording medium in a printing device, the moving speed of the print head is reduced by a predetermined percentage, and then the print head is moved to the platen. Since the printing head is stopped while entering the retreat area, the printing head can be smoothly decelerated even during high-speed printing operations. Furthermore, the print head can be reliably stopped with the platen in the retracted state, and the continuous conveyance of the recording medium can be carried out even more smoothly. Additionally, there is no need for additional mechanical transmission elements such as clutches, no special power is required for driving the platen since the power that drives the print head drives the platen, and sensors etc. Since sensors for control or print timing generation can be used, the device can be easily configured.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the structure of a shuttle head type printing device, Fig. 2 is a front view of the printing device shown in Fig. 1, Fig. 3 is a diagram showing the operation timing of the printing device, and Fig. 4 is a main Fig. 5 is a block diagram showing the configuration of a control system for carrying out the invention, Fig. 5 is a block diagram showing the structure of a drive system for carrying out the invention, and Fig. 6 shows the operation during normal printing operation in the invention. FIG. 7 is a diagram showing the operation timing when entering the medium conveying operation from the normal printing operation in the present invention. 1...Main body, 2...Shuttle head, (printing head), 4...Platen, 6...Eccentric cam, 9...Space motor (drive motor), 11...Screw gear, 17
...Print position detection sensor, 18...Platen position detection sensor, 20...Feed roller, 21...Paper feed motor, 30...Motor speed control unit, 31
…Space motor driver (motor driver),
32...Timing control section, 33...Paper feed motor driver, 34...Print character buffer shape generating section, 35...Print control section, 36...Print pin magnet driver, 37...Print pin magnet.

Claims (1)

[Scope of Claims] 1. A print head that reciprocates in the longitudinal direction of the guide shaft, a drive motor that moves the print head in the longitudinal direction of the guide shaft, a motor speed control section that controls the speed of the drive motor, and a motor speed controller that controls the speed of the drive motor. a motor driver that conducts a drive current based on a determination by a speed control section; a platen that is provided opposite to the print head and moves forward and backward with respect to the print head in conjunction with the reciprocating movement of the print head; a print position; a timing control unit that determines whether to print or feed the paper based on the platen position and recording medium conveyance preparation state;
In the printing device having a printer, the motor driver lowers a drive current value based on an instruction from the motor speed control section when sucking in or ejecting a recording medium, and reduces the moving speed of the print head by a predetermined percentage, and at the same time reduces the printing speed. causing the head to perform one cycle of pseudo reciprocating movement, causing the timing control section to monitor the forward and backward positions of the platen in conjunction with this reciprocating movement, and based on the monitoring results, the timing control section issues a current cutoff instruction. A method for controlling a head movement speed of a printing apparatus, characterized in that the driving current from the motor driver is cut off, and the printing head is stopped while the platen is in a retraction area.