JPH0313988B2 - - Google Patents

Description

[Detailed description of the invention] Technical field The present invention relates to serial printers.

Conventionally, in the above-mentioned type of serial printer, an electromagnetic solenoid in a print head placed and fixed on the carriage is operated by a drive motor while reciprocating the carriage in both directions along the printing lines of printing paper. It is configured to print characters in a dot matrix format by selectively driving the printing wire, and when short line printing in which fewer than a predetermined number of characters are printed in one printing line continues over several lines, the driving Since the motor is supplied with a large current necessary for starting up and stopping under braking within a short period of time, the temperature rise causes deterioration of the drive characteristics, making it impossible to move the carriage to the desired printing position, and furthermore, the excitation coil There was a risk of burnout.

Purpose of the Invention In view of the above-mentioned drawbacks of the conventional art, the purpose of the present invention is to prevent deterioration of drive characteristics due to temperature rise of the drive motor when several lines of short lines are printed in succession using a simple configuration, thereby improving the carriage performance. It is an object of the present invention to provide a serial printer that can move to a desired printing position and that can prevent excitation coils from burning out.

Composition of the invention Hereinafter, the present invention will be explained according to one embodiment.

FIG. 1 is an explanatory diagram showing an outline of a serial printer according to the present invention.

In the figure, a carriage 1 is inserted into a guide rod 2 fixed to a main body frame (none of which is shown) parallel to the axis of the platen so as to be able to reciprocate.

The drive motor 3 is a drive wire that is stretched between a drive pulley 5 rotated through a gear 4 having an appropriate reduction ratio and a driven pulley 6 that is pivotally supported on the main body frame, with both ends fixed to the carriage 1. 7, the carriage 1 is reciprocated in both directions along the printing lines of the printing paper 8.

The print head 9 is mounted and fixed on the carriage 1, and prints characters in a dot matrix format by selectively driving print wires (none of which are shown) using a number of electromagnetic solenoids.

Fig. 2 is an electrical block diagram of the serial printer, Fig. 3 is a flowchart showing the operating state, Fig. 4 A and B are explanatory diagrams showing the carriage movement state in the normal printing state, and Fig. 5 A and B is an explanatory diagram showing the movement state of the carriage when printing a shot line, Figures 6A and B are explanatory diagrams showing the movement state of the carriage when printing a shot line with a dummy print position added, and Fig. 7 is an explanatory diagram showing the movement state of the carriage when printing a shot line. It is an explanatory diagram showing a state.

In the figure, a control device 10 sequentially stores print data PD input from an external device 11 such as a keyboard or a host computer in a buffer memory 12, and when print data PD for one print line is stored in the buffer memory 12, the buffer memory 12 The command signal DS is output to the drive circuit 13 based on the print data PD for one print line accessed from
The dot pattern data corresponding to the print data PD is moved in both directions along the print line of the print data PD.
The DPD is accessed from the pattern memory 10a and output to the print head 9, and characters are printed by selectively driving the print wire. The control device 10 stores the print data PD of the next print line inputted from the external device 11 in the buffer memory 12 during the printing operation.

When the carriage 1 is moved, if the number of printed characters in one printing line is more than a predetermined number, the control device 1
0 causes the carriage 1 to rise to a predetermined speed v1 at the rise time tr shown in FIGS. 4A and B, and the predetermined speed v
1, the carriage 1 is idled for an idle running time _t0 , and then moved at a constant speed at a substantial printing position for a printing time tp1 corresponding to the number of characters to be printed. After the carriage 1 is run idle at a predetermined speed v1 for the idle running time _t0 , the drive motor 3 is reverse excited and stopped at a braking time tf.

On the other hand, in the case of short line printing in which the number of printed characters in one printing line is less than a predetermined number (for example, 5 characters or less), the control device 10 operates as shown in FIG.
The carriage 1 is started up to a predetermined speed v1 at the rise time tr shown in B, and the idle running time t ₀ is reached at the predetermined speed v1.
After running idle for a period of time, the actual printing position is moved at a constant speed for a printing time tp2 corresponding to the number of characters to be printed.
After the carriage 1 runs idle at the predetermined speed v1 for a idle running time _t0 , the drive motor 3 is reverse excited and stopped at a braking time tb.

When the above-mentioned shot line is printed continuously over several lines, a large current is supplied to the drive motor 3 within a short period of time, so the motor temperature of the drive motor 3 changes due to its drive characteristics, as shown in Fig. 7. When the temperature rises to near the limit temperature Tl that causes deterioration or burnout of the excitation coil, the control device 10 uses the detection signal SS from the temperature sensor 14 such as a thermocouple attached to the drive motor 3 as shown in FIG. It is determined whether the motor temperature has reached a predetermined temperature T1 below the limit temperature Tl, and if the determination is NO, the carriage 1 is moved according to the operation shown in FIG. 4 or FIG. 5 described above. On the other hand, if the above judgment is YES, the print data PD input from the external device 11
Based on this, it is determined whether or not a short line will be printed, and if the determination is NO, the carriage 1 is moved in the same manner as above. On the other hand, if the determination is YES, the control device 10 sets a blank feed area consisting of the blank feed time td on both sides of the actual print position of the print line where the shot line is printed, and sets a blank feed area on both sides of the actual print position. The drive motor 3 is continuously driven so that the carriage 1 moves throughout the empty feed area.

That is, when the temperature of the drive motor 3 has reached the predetermined temperature T1 due to shot line printing over multiple lines, and when the shot line printing is continued, the control device 10 controls the drive motor 3 as shown in FIG. After the carriage 1 is started up to a predetermined speed V1 at a predetermined rise time tr and run idle for a predetermined idle running time t0, a dummy print position is set to one of the actual print positions, i.e. A predetermined blank feed time td according to the blank feed area, a predetermined printing time tp3 according to the actual print position, and a predetermined blank feed time td according to the blank feed area set at the other side of the actual print position. Predetermined idle running time t0
After controlling the drive motor 3 so that it moves continuously during this period, the drive motor 3 is reverse excited to stop the carriage 1 at a predetermined braking time tf. As a result, even when printing a shot line, the continuous drive time of the drive motor 3 is the idle feed time td.
By increasing the length by twice as long as , the current per hour supplied to the drive motor 3 is reduced, the heat generated by the drive motor 3 is reduced, and the temperature of the drive motor 3 is lowered.

When the motor temperature drops to the constant temperature T2 shown in FIG. 7 due to the above operation, the control device 10 cancels the addition of dummy printing positions on both sides of the actual printing position, and follows the operation shown in FIG. 4 or 5. and move the carriage 1.

Therefore, in this embodiment, when the motor temperature of the drive motor 3 reaches the first predetermined temperature T1 due to shot line printing, a predetermined space corresponding to the dummy time td is placed at the actual printing position until the motor temperature decreases to a constant temperature. By setting the idle feed area according to the feed time td and increasing the driving time of the drive motor 3 according to this idle feed area, the current supplied to the drive motor 3 per hour is reduced and heat generation is reduced. However, the temperature can be lowered. This prevents deterioration of the drive characteristics of the drive motor 3 and burnout of the excitation coil even when short line printing is continued, making it possible to print characters with high quality.

FIG. 8 is a flowchart showing a second embodiment of the present invention, in which the control device 10 includes a first counter N for counting the number of printed lines of short line printing;
A second counter M is also provided for counting the number of lines printed in shot line printing in which a blank feed area is added to at least one of the actual printing positions.
Then, the control device 10 determines whether short line printing is to be performed based on the print data PD stored in the buffer memory 12, and if the determination is NO, the first
After resetting the counter N and the second counter M, the carriage 1 is moved according to the operation shown in FIG. On the other hand, if the above judgment is YES,
After counting up the first counter N,
It is determined whether the count number of the first counter N has reached a predetermined value a corresponding to a predetermined temperature T1 that is below the motor limit temperature, and if the determination is NO, after resetting the second counter M. , move the carriage 1 according to the operations shown in FIG. On the other hand, if the above determination is YES, it is determined whether the count number of the second counter M has reached the predetermined number of rows b, and if the determination is NO, after counting up the second counter M, A blank feed area is set in at least one of the actual printing positions, and the drive motor 3 is drive-controlled so that the carriage 1 continuously moves across these blank feed areas and the actual printing position, and the driving time of the drive motor 3 is set. By making the length substantially longer, the current supplied per hour is reduced, thereby suppressing heat generation and lowering the temperature. Then, continue printing the short line according to the above operation,
When the second counter M reaches the predetermined number of rows b, the first counter N and the second counter M are reset, respectively, and the carriage 1 is moved according to the operations shown in FIGS. 4 and 5.

Note that the count values a and b of the first counter N and the second counter M were experimentally determined to be values suitable for the printer in consideration of the drive speed and performance of the drive motor 3, the usage environment of the printer, etc. It is something. Furthermore, in the first and second embodiments, the blank feed area is added to both sides of the actual printing position, but
The present invention can also be implemented with a configuration in which an idle feed area is added to at least one of the actual printing positions to reduce the motor temperature.

EFFECTS OF THE INVENTION As explained above, the present invention allows a carriage on which a printing head is mounted to be moved reciprocally along a printing line by a drive motor driven based on a command signal from a control device, and a predetermined number of characters are printed on one printing line. In a serial printer that is capable of short line printing that prints the following characters, the control device automatically controls when the temperature of the drive motor increases due to continuous multiple line print lines and the subsequent print line is short line printing. By setting a blank feed area for the print head at at least one of the print positions and moving the print head across the entire area between the actual print position and the blank feed area, when short line printing is continuous over several lines, The present invention is a serial printer that can prevent the drive characteristics of the drive motor from deteriorating due to a rise in motor temperature, move the carriage to a desired actual printing position, and prevent the excitation coil from burning out.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the outline of the serial printer according to the present invention, Fig. 2 is an electrical block diagram of the serial printer, Fig. 3 is a flowchart showing the operating state, and Fig. 4 A and B are normal printing. An explanatory diagram showing the movement state of the carriage in the state, FIG. 5A,
B is an explanatory diagram showing the moving state of the carriage when printing a shot line, FIGS. 6A and B are explanatory diagrams showing the moving state of the carriage when printing a shot line with a blank feed area added, and FIG. FIG. 8 is a flowchart showing the operating state of the second embodiment of the present invention. In the figure, 1 is the carriage, 3 is the drive motor, and 9
1 is a print head, 10 is a control device, 14 is a temperature sensor, T1 is a predetermined temperature, T2 is a constant temperature, N is a counter, and a is a predetermined value.

Claims (1)

[Scope of Claims] 1. Printing a predetermined number of characters or less on one printing line while reciprocating the carriage carrying the printing head along the printing line by a drive motor driven based on a command signal from a control device. In a serial printer that is capable of printing a shot line, the control device is configured to control at least one of the actual printing positions when the temperature of the drive motor has increased due to continuous printing of a plurality of lines of shot lines, and when the subsequent printing line is a shot line printing. A serial printer characterized in that a blank feed area for the print head is set, and a drive motor is continuously driven to move the print head throughout the actual printing position and the blank feed area. 2. The serial printer has a temperature sensor that detects the temperature of the drive motor, and when the temperature sensor detects a predetermined temperature and the subsequent print line is shot line printing, the control device determines whether the temperature of the drive motor is at a predetermined temperature. Set a blank feed area at the actual print position of the print line of shot line printing, and continuously drive the drive motor to move the print head between the actual print position and the blank feed area until the temperature drops below . A serial printer according to claim 1. 3. The control device is provided with a counting means for counting the number of printed lines of continuous shot line printing, and when the count value of the counting means reaches a predetermined number and the subsequent printed line is shot line printing, the number of consecutive shot line printing is 2. The serial printer according to claim 1, wherein a blank feed area is set at the actual printing position of the print line, and the drive motor is drive-controlled so as to move the print head between the actual printing position and the blank feed area.