JPH0557921A - Line printer - Google Patents

Abstract

PURPOSE:To form printing images without interruption of continuity by a method wherein, when the amount of printing data for a sheet of label is larger than the capacity of an image buffer, the printing data therein is replaced in a plurality of portions and, at the time of replacement, the printing is restarted at the place of overlapping the already printed part. CONSTITUTION:In a label printer, after the printing data input therein is stored in an image buffer 18 in only an amount corresponding to a sheet of label (recording medium), a CPU 10 gives an instruction of the printing to drive a thermal head 2 and a motor 15, thereby performing a predetermined printing on the label. When the amount of the printing data corresponding to a sheet of label is larger than the capacity of an image buffer 18, after the printing is performed based on the image data stored in the image buffer 18, the image data therein is replaced with an unprinted printing data to continue the printing At the time of the printing data replacement, a label 3a is back fed and the printing is so controlled as to restart at the place of slightly overlapping the already printed part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention selectively forms a plurality of dots at a time in the line direction, and feeds a recording medium in a direction orthogonal to the line direction so that desired characters, figures, etc. can be formed on the recording medium. The present invention relates to a line printer for printing.

[0002]

2. Description of the Related Art As one of the devices of this type, FIG. 5 shows a conventional example of a thermal label printer. First, a thermal head 2 as a print head is provided so as to be able to come in contact with and separate from the platen 1, and a label mount 3 is arranged between the platen 1 and the thermal head 2.
The label mount 3 is formed by winding a long mount 3b, to which a large number of labels 3a as recording media are attached at regular intervals, in a roll shape, and the support shaft 4 Supported by. And the platen 1
A peeling plate 5 is provided at a position where the labeled mount 3 passing between the thermal head 2 and the thermal head 2 is guided, and the label 3a is peeled from the mount 3b by the peeling plate 5, and only the mount 3b is provided. Is wound around the winding shaft 6.

An ink ribbon 8 held in a stretched state between a pair of ribbon holding shaft 7a and ribbon winding shaft 7b is guided between the thermal head 2 and the label mount 3. ing.

In the case of such a structure, the ink of the ink ribbon 8 is melted by the selective heat generation of the heating element (not shown) of the thermal head 2, and the ink adheres to the label 3a to form a dot for one line. It is selectively formed. Then, the desired printing is performed on the label 3a by the selective formation of such dots and the feeding of the labeled mount 3 by the rotation of the platen 1 and the winding shaft 6, and the label 3a after printing is mounted on the release plate 5 as the mount. It is peeled off from 3b and issued.

On the other hand, in the conventional printer, the print data is coded in order to speed up the print data processing in the printer and the transmission / reception of the print data between the printer and another device. In general, the coded print data is handled and stored as image data in an image buffer connected immediately before the print head, and the print head is driven based on the image data. However, in the thermal type label printer as illustrated in FIG. 5, since the image buffer capacity is usually set to be small, the print data may run out of the image buffer capacity. This is inconvenient because it is impossible to print all the print data corresponding to the label 3a on the label 3a.

Therefore, conventionally, when the print data is stored in the image buffer to the full capacity, printing is performed for that amount, and the remaining print data is replaced in the image buffer and printing is continued, whereby one label is printed. A thermal label printer having a structure capable of printing all print data corresponding to 3a has been considered and put into practical use. FIG. 6 exemplifies a printing result by the thermal type label printer having such a structure. In FIG. 6, the portion corresponding to the length a is the capacity of the image buffer. Therefore, the image data corresponding to the portion a is printed image 9
After being printed on the label 3a as a, the image data corresponding to the remaining portion b is continuously printed as the printed image 9b, so that all the print data corresponding to one label 3a is printed on the label 3a. The image 9 is printed.

[0007]

The feeding of the labeled mount 3 to the thermal head 2 is performed by a drive unit such as a motor (not shown) through a power transmission system (not shown), and the take-up shaft 6 of the mount 3b, the platen 1 and the like. It is generally performed by applying a driving force to the. At this time, for example, when a continuous printing method is adopted in which the print image 9b is continuously printed and then the print image 9b is completed to complete the print image 9, when the print data is replaced in the image buffer, the print end position is changed. Unless the feed of the labeled mount 3 is stopped accurately and surely, the printed image 9a and the printed image 9b
A break as illustrated in FIG.

However, due to the tolerances of the gears used in the power transmission system, the distortion of the platen 1, the slow-up at the start of printing, the slow-down at the end of printing, etc., the feed of the labeled mount 3 is actually fed. It cannot be stopped at the print end position. Therefore, in the label printer adopting the continuous printing method of this kind, the printed image 9 is notched at the position where the printing data is replaced with respect to the image buffer, and the image quality is inferior.

[0009]

SUMMARY OF THE INVENTION According to the present invention, the drive of a line type print head based on image data stored in an image buffer and the drive of a feed unit for feeding a recording medium are synchronized with each other so that a predetermined amount can be obtained on the recording medium. A printing means is provided for printing, and when the amount of print data corresponding to one recording medium is larger than the capacity of the image buffer, the print data is exchanged into this image buffer in multiple times and printing is performed based on the print data for each time. And a position correction means for back-feeding the recording medium to slightly overlap the printing restart position with the already printed portion when the continuous printing means replaces the print data in the image buffer. It was

[0010]

Therefore, when the amount of print data corresponding to one recording medium is larger than the capacity of the image buffer, the printing means performs printing based on the image data stored in the image buffer, and when the printing is completed, continuous printing is performed. The unprinted print data is replaced by the image buffer by the means, and printing based on the new image data is performed by the printing means. Then, by repeating the same operation, a complete image based on all print data corresponding to one recording medium is formed on the recording medium. on the other hand,
When the print data is replaced in the image buffer, the recording medium is back-fed by the position correcting means, and the printing by the printing means is restarted from the position slightly overlapped with the already printed portion. As a result, even if the recording medium is idly fed due to the tolerance of the gears of the feed portion, the print end position and the print restart position are not separated, and no break is generated in the completed image.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS. 1 to 4 (a) (b).
A description will be given based on (c), (d) and (e). The same parts as those described based on FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.
First, the electrical connection in this embodiment is shown in the block diagram of FIG. That is, the CPU 10 that intensively performs various processes
The CPU 10 is connected with a communication interface 11 serving as a window for print data from an external device, and is also connected with a ROM 12 and a RAM 13. The ROM 12 has a structure for storing fixed data such as an operation program, and is an EPROM, for example. On the other hand, the RAM 13 has a structure for storing rewritable variable data, and is composed of both static RAM and dynamic RAM.

Next, a motor 15 is connected to the CPU 10 via a motor driver 14. A stepping motor is used as the motor 15 and is used as a drive source for the platen 1, the winding shaft 6, the ribbon winding shaft 7b, and the like. Further, the motor 15, the platen 1, the winding shaft 6, and the like constitute a feed unit 16 that feeds the labeled mount 3. here,
The number of drive pulses given to the motor driver 14 is counted by the CPU 10, and the counted number is stored in a printing step counter 13a provided in the RAM 13. The print step counter 13a counts up or down the number of drive pulses given to the motor 15 from the start of printing to the end of printing, with 0 at the start of printing on one label 3a. It is of structure. In the printing step counter 13a,
When the normal rotation output to the motor 15 is performed, the count-up is performed, and when the reverse rotation output is performed, the count-down is performed.

The thermal head 2 is connected to the CPU 10 through a head driver 17, and the head driver 17 includes an image buffer 18. The image buffer 18 has a structure for holding the coded and expressed print data received by the communication interface 11 as image data suitable for the thermal head 2.

Further, various sensors 19 such as a ribbon end sensor, a label end sensor, and a head-up sensor are connected to the CPU 10 via an I / O 20, and drive pulses applied to the motor driver 14 are controlled. A timer 21 that emits a fixed-cycle pulse that serves as a reference for the interval is also connected to the CPU 10.

In such a configuration, the printing operation is CP
The printing means 22 is composed of U10, the thermal head 2, the motor 15 and the like. That is, ROM1
Communication interface 1 according to the operation program in 2
The print data input from 1 is stored in the image buffer 18 in an amount corresponding to one label 3a. At this time, the encoded print data is the thermal head 2
Is converted into image data suitable for printing and stored in the image buffer 18. Then, the CPU 10 issues a print command to the head driver 17 and the motor driver 14, and the thermal head 2 and the motor 15 are driven in accordance with the print command, so that a predetermined print is performed on the label 3a. More specifically, the ink of the ink ribbon 8 is melted by the selective heat generation of a heating element (not shown) of the thermal head 2 and adheres to the label 3a, so that dots for one line are selectively formed and the motor When the platen 1 and the winding shaft 6 driven by 15 rotate, the labeled mount 3 is fed, and the predetermined printing is performed on the label 3a.

Next, the flow of operation when the amount of print data for one label 3a is larger than the capacity of the image buffer 18 will be described with reference to the print progress chart of FIG. 4 and the flow charts of FIGS. First, the CPU 10 determines whether or not the amount of print data exceeds the capacity of the image buffer 18. If the print data amount does not exceed the limit, printing in the normal print mode is performed. Switch to mode. However, in the implementation, when there is print data that does not fit in the image buffer 18 when the image data is formed in the image buffer 18, or the image buffer 1
It is also possible to perform a process of shifting to the continuous print mode when, for example, unprinted print data remains when the image data in 8 is printed on the label 3a.

In the continuous print mode, however, the continuous print means performs the continuous print processing, and in the process, the position correction means does not cause a break in the printed image 9. The flow of operation in the continuous print mode will be described below step by step.

Step 1 In step 1, printing is performed based on the first half print data. That is, the print step counter 13a is cleared, and the first half of the print data is formed and stored in the image buffer 18 as image data. Then, the normal rotation output command to the motor 15, the print command to the thermal head 2, and the count number of the drive pulse given to the motor driver 14 are set in the CPU 10 by a method such as bit setting. The number of drive pulses counted here is the number of drive pulses corresponding to the feed amount of the labeled mount 3 required for printing the image data stored in the image buffer 18.

After the predetermined setting, the interrupt processing shown in FIG. 3 is started. In this interrupt process, since the print command is set, both the thermal head 2 drive and the motor 15 normal rotation drive are performed, and a dot for one line is formed on the label 3a. After the dot formation, since the forward rotation output command is set, the printing step counter 13a is incremented by 1 and the process returns to the flowchart of FIG. The interrupt processing shown in FIG. 3 is continued until the count number of the print step counter 13a reaches the set count number, that is, until it counts up, and at the time of the count-up, the image data stored in the image buffer 18 is converted. A base image is formed on the label 3a, and the print command and the count number are reset.

Here, FIGS. 4 (a) to 4 (e) show the printing process when a capital letter A is printed over the label 3a.
The print image 25 at the time when the print step counter 13a counts up in step 1 is illustrated in FIG. The dot-dash line in FIG. 4 indicates the printing position A, that is, the position of the heating element of the thermal head 2.

Step 2 Next, in step 2, the slow-down drive processing of the motor 15 is performed. That is, after the slowdown command and the count number of drive pulses required for slowdown driving are set, the process proceeds to the interrupt process of FIG. In this interrupt processing, the print command has already been reset, so the motor 1
Only the positive rotation drive of 5 is performed, and the printing step counter 1
3a is increased by one step, and the process returns to the flowchart of FIG. Such interrupt processing is continued until the print step counter 13a counts up.
At this time, since the slowdown command is set, the interval between the drive pulses given to the motor driver 14 is widened step by step. As a result, the rotation of the motor 15 is gradually slowed and the labeled mount 3 is slow-down fed.

When the printing step counter 13a counts up, the forward rotation output command, the slowdown command, and the count number for the motor 15 are reset. At this time, the label mount 3 is printed at the print position A, which is the print end position.
Is further fed, and the state shown in FIG.
The slow-down feed amount of the labeled mount 3 by the slow-down drive of the motor 15 is, for example, 10 mm.

Step 3 Next, in Step 3, backfeed operation processing of the mount 3 with label is performed. That is, the reverse rotation output command to the motor 15 and the driving pulse count number are set, and the process proceeds to the interrupt process shown in FIG. Here, the number of drive pulses counted is the number of drive pulses required for backfeed of the labeled mount 3 excluding the number of pulses required for slowdown feed performed at the end of backfeed in step 4 described later. Is.

In the interrupt process, since the print command is not set, only the reverse rotation drive of the motor 15 is performed, and since the reverse rotation output command of the motor 15 is set, the print step counter 13a is lowered by one step. As a result, the labeled mount 3 is back-fed, and when the printing step counter 13a counts up, the count number of drive pulses is reset. The motor 15
The back feed amount of the labeled mount 3 by the reverse rotation drive of is, for example, 30 mm.

Step 4 In step 4, the slow-down drive processing of the motor 15 similar to step 2 is performed. That is, after setting the slow down command and the count number of the drive pulse, FIG.
After the reverse rotation drive of the motor 15, the print step counter 13a is stepped down by one step and the same operation is repeated until the print step counter 13a counts up. After the count up, the reverse rotation drive command for the motor 15 is issued. , The slowdown command and the count number are reset. Here, the count number of the drive pulses set in step 4 is the number of drive pulses of the motor 15 necessary for the slowdown drive, as in step 2. Therefore, the label mount 3 is 10 mm
Min slowdown backfeed, step 3 3
With the back feed of 0 mm, the labeled mount 3 is back fed by 40 mm. FIG. 4 (c) shows the positional relationship between the labeled mount 3 and the printing position A at this time.

Step 5 In step 5, a process of moving the print restart position in step 6 described later to the print position A is performed. That is, the latter half of the print data is formed and stored as image data in the image buffer 18, and the forward rotation output command for the motor 15 and the driving pulse count number are set. The count number of the drive pulse is a number corresponding to the drive pulse required to feed the labeled mount 3 so that the print restart position is moved to the print position A.
As a result, the motor 15 is driven to rotate in the normal direction to feed the label-mounted backing sheet 3 and the printing step counter 13a is incremented by one step. Therefore, the same operation is repeated until the print step counter 13a counts up, and the print restart position is moved to the print position A. This moment is shown in FIG. At this time, the count number of the drive pulse is reset.

Here, the mount 3 with a label in step 5 is used.
Is 29.64 mm, which is a theoretical value for matching the print end position with the print position A.
Not mm. This is because, due to a mechanical error or the like of the feed unit 16, there is a case in which a blank feed of about 0.36 mm occurs after the driving of the motor 15 is stopped and before the labeled mount 3 is actually stopped. .. That is, in the present embodiment in which the driving of the motor 15 is stopped twice in step 2 and step 4, when the labeled backing sheet 3 is idly fed only in step 2, the labeled backing sheet 3 is moved to 30 m in step 5.
After feeding m, the print end position is 0.
About 36 mm is passed, and a gap of 0.36 mm is opened between the print end position and the print restart position. Therefore, by setting the feed amount of the labeled mount 3 in step 5 to 29.64 mm as in this embodiment, the print restart position coincides with or overlaps the print end position, and the print end position is There is no gap between the print restart position and the print restart position.

Step 6 In step 6, printing is performed based on the print data of the latter half. That is, the print command and the count number of the drive pulse corresponding to the feed amount of the label mount 3 required for printing are set, and the interrupt processing of FIG. 3 is performed. In this interrupt process, since the print command is set, both the thermal head 2 drive and the motor 15 normal rotation drive are performed, and a dot for one line is formed on the label 3a. Then, the print step counter 13a is incremented by one step, and the same operation is continued until the print step counter 13a is counted up. When the count step is incremented, the print command, the forward rotation output command to the motor 15 and the count number are reset and continued. Print mode ends.
At this time, as shown in FIG. 4 (e), a print image 25 based on all print data corresponding to one label 3a is formed on the label 3a, and the already-printed label 3a and the next label 3a are formed.
The intermediate portion of the line a is located at the printing position A.

As described above, in this embodiment, the first half of the print data is created as image data in the image buffer 18 in step 1 and printing is performed based on this, and the second half of the print data is image data in the image buffer 18 in step 5. Then, the printing based on this is performed in step 6, and the printed image 25 based on all the printing data corresponding to one label 3a is formed. Therefore,
The step 1, step 5, and step 6 constitute the continuous printing means. Further, in the process of such continuous printing, when the print data is exchanged to the image buffer 18, the label mount 3 for feeding the print restart position to the print end position is fed in steps 2 to 5. Therefore, these steps 2
The position correction means is composed of 5 to 5. And
Since this position correction means is provided, the print restart position does not separate from the print end position, and the print image 25 is formed on the label 3a with no breaks in the middle, so that the print quality is improved.

In practice, the print data in the image buffer 18 may be replaced more than once. In this case, in the flowchart of FIG. 2, the processes from the storage of the print data in the image buffer 18 in step 1 to step 4 may be repeated a required number of times until the last print data replacement. Further, in the implementation, a position correction means may be configured so that only the backing sheet 3 with the label is fed back so that the print restart position slightly overlaps the print end position.

[0031]

According to the present invention, when the amount of print data corresponding to one recording medium is larger than the capacity of the image buffer, the print data is exchanged into the image buffer in a plurality of times by the continuous printing means and printing is performed at each time. By continuing the printing based on the data, a complete image based on all the printing data is formed on the recording medium. At this time, a position correcting means is provided, and the recording medium is back-fed when the printing data is replaced to the image buffer. Since the printing is restarted from a position slightly overlapping the already printed portion, the recording medium may be idly fed due to the tolerance of the gear used in the feeding portion that feeds the recording medium. Also, it is possible to form a printed image with no breaks in the middle, and thus improve the printing quality. It has the effect of equal.

[Brief description of drawings]

FIG. 1 is a block diagram of electrical connection of each part showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of operation processing.

3 is a flowchart showing a flow of interrupt processing in the flowchart of FIG.

FIG. 4 is a plan view of a label mount showing the progress of the printing operation when the amount of print data is larger than the capacity of the image buffer, and (a) shows all the image data initially formed in the image buffer. The moment when the drive of the motor is stopped, the moment when the drive of the motor is stopped, and the moment when the drive of the motor is stopped after the back feed of the labeled mount,
(D) shows the moment when the mount with label is fed to the printing restart position, and (e) shows the moment when printing on one label ends.

FIG. 5 is a side view showing an example of a conventional thermal label printer.

FIG. 6 is a plan view of a mount with label showing an example of a print result on a label.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Platen 2 Print head 3a Recording medium 16 Feed part 18 Image buffer 22 Printing means

Claims (1)

[Claims] 1. A line-type print head that comes into contact with a platen via a recording medium, a feed unit that feeds the recording medium guided between the print head and the platen, and print data stored as image data. And an image buffer for driving the print head based on the image data stored in the image buffer and driving the feed unit in synchronization with the drive to perform predetermined printing on the recording medium, When the amount of print data corresponding to one of the recording media is larger than the capacity of the image buffer, the print data is exchanged into the image buffer in a plurality of times, and the print means performs printing based on the print data for each time. Continuous printing means to
A line printer provided with position correction means for back-feeding the recording medium to slightly overlap the print restart position with the already-printed portion when the print data is replaced in the image buffer by the continuous print means.