JPS60174677A - Printing system for line printer - Google Patents

Abstract

PURPOSE:To enable the relative movement of a head and a paper to be securely stopped before a printing-starting position in the next line is reached, by a method wherein a means is provided for detecting the printing of a dot at a predetermined position during printing dots in a line, and a DC motor is stopped during printing in the line in response to an output from the detecting means. CONSTITUTION:A controlling circuit 1 rotates the motor 2 forward when the completion of reception of data for one dot line is detected through a reception completion signal 30. When the paper is fed to a predetermined printing-starting position (x), data stored in a printing buffer 5 are fed to the printing head by one group at a time, thereby printing. When a predetermined printing position, e.g., printing of the 6th group, is detected during printing dots in a line, the circuit 1 stops the operation of the motor 2. Even after this stoppage, the paper is fed by inertia, and printing of the 6th and later groups is conducted during the inertial paper feeding. The feeding of the paper is stopped whe the head 7 reaches, for example, a position (y). Accordingly, since the driving of the motor 2 is stopped by taking the inertial rotation into consideration, the position of the head 7 relative to the paper is prevented from coming beyond a prescribed printing-starting position in the next line.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a line printer, in particular, a DC system for paper feeding of printing paper.
The present invention relates to a printing method of a line printer using a motor.

[Prior art]

Generally, line printers use a stepping motor to feed paper, so simply rotating the stepping motor by a predetermined angle after printing one line allows the print head to wait at the position to start printing the next line. can.

However, since stepping motors are expensive, it may be possible to replace them with inexpensive DC motors. In this case, for example, in the case of a printer having a thermal line head in which 1M dots are arranged in N groups to form one line, graphic data is printed as shown in FIG. 1, for example. That is, when the data of one dot line (MXN dot) is received from the host computer (steps 101, 102), and the paper is fed to a predetermined position (step 103),
104) Start printing (step 105). Then, one group, that is, printing of M dots by heating is repeated N times to print one dot line. Meanwhile, the next data is received on the other hand, and if the data reception for the next line is completed when printing of one dot line is completed (steps 106 to 108), printing of the next line is immediately started, but the data transmission speed is If the speed is slower than the printing speed, or if the data has been interrupted and reception of the next line of data has not yet been completed, the motor is stopped (step 109) and data reception is shifted to step 110. ), after receiving one dot line (step 11
1) Rotate the motor again and start printing the next dot line.

However, even if the motor is stopped after one line has been printed, the DC motor does not stop immediately due to its inertia, and the gap between the dot lines increases to accommodate the extra paper feed, resulting in the printing of several lines. A problem arises in that the print data made up of the dots becomes unclear or illegible.

[Object and structure of the invention]

The present invention was developed in view of the above circumstances, and its purpose is to solve the problem of excessive paper feeding due to motor inertia and to realize an inexpensive line printer using a DC motor. The purpose is to provide a printing method for printers.

In order to achieve such an object, the present invention provides a printing position detection means for detecting dot printing at a predetermined position during printing of one line of dots, and uses the detection output to detect dot printing in the middle of printing of one line. The operation of the DC motor is stopped so that paper feed always stops before the printing start position of the next line. Hereinafter, the present invention will be explained in detail using Examples.

〔Example〕

FIG. 2 is a configuration diagram showing an embodiment of the present invention. In the figure, reference numeral 1 denotes a control circuit consisting of a computer equipped with a well-known CPU, and a motor 2 is driven via a drive circuit 3 in accordance with commands from the control circuit 1. On the other hand, print data 10 sent from a host computer (not shown) is added to the reception buffer 4 by a read signal 20 from the control circuit 1. 3
0 is a signal indicating completion of reception. The received data is further written into the print buffer 5 by a write signal 40 from the control circuit 1, and data for each group is sequentially sent to the drive circuit 6 by a read signal 50. At the same time, a select signal 60 is sent from the control circuit 1 to the drive circuit 6, and printing of the corresponding groups of the print heads T is performed in sequence. Note that 70 is a clock signal for timing control.

FIG. 3 is a flowchart showing an example of the control operation in the control circuit 1. In the figure, when the control circuit 1 detects the completion of data reception of the first dot line based on the reception completion signal 30 (steps 201 and 202), it causes the motor 2 to rotate in the normal direction (step 203) as in the conventional case. and,
As shown in FIGS. 4(a) and 4(b), when the paper is fed to the predetermined print start position Feed and print (step 205). To detect the printing start position, for example, a method can be used in which a blade is attached to the rotating shaft of the motor so that a constant pulse is generated every rotation, and the rotational pulses are counted.

Note that FIG. 4(b) is a detailed view of the area surrounded by the dashed line in FIG. 6). Also, in the same figure (,) the center opening is the printing paper 80.
Indicates the direction of paper feed.

While receiving the next data as in the past (step 206
) Printing of hook groups is performed in sequence, and if a predetermined printing position, for example, printing of the 6th group is detected during printing of i-line dots (step 20T), the control circuit 1 stops the operation of the motor 2 at that point. (Step 20B).

In this embodiment, the control circuit 1 itself controls the transfer of data sent one group at a time from the print buffer 5 to the print head T, so the detection of the printing position can be performed in the control circuit 1 itself.

Even if the driving of the motor 2 is stopped, the paper continues to be fed due to inertia, and during this time, printing of the sixth group and subsequent groups is performed (step 209). Paper feeding.

Eventually, the head 7 comes to a stop at the y position, for example. Since the drive of the motor 2 is stopped in advance in consideration of rotation due to inertia, the next line will not exceed the prescribed printing start position.

After printing up to N groups has been completed (step 209), if data reception for the next line has been completed, or if it has not been completed, wait for completion (steps 210 and 2).
11, 212), the motor 2 is rotated normally again to feed the paper, and when the head 7 reaches the specified print start position 2, printing is started (steps 203 to 205). The printing start position Z is detected by counting the rotational pulses of the motor as described above.

If the reception of data for the next line is completed before printing of the 6th group of 1 line is started, the motor 2 is not stopped and the paper is continuously fed until the head 7 reaches the 2nd position. Perform printing (steps 207, 209, 2)
10 (~212), 203-205).

Although the case where a thermal line head is used has been described as an example, the present invention is not limited to this recording method, and is generally applicable to printers using other recording methods such as an inkjet type.

Further, in the above-described embodiment, one line is divided into N groups and printed, but it goes without saying that printing may be performed sequentially at high speed, for example from the first printed body to the final printed body. In that case, for example, the Xth dot printing position may be detected and the operation of the motor may be stopped.

The timing for stopping the operation of the motor may take into account the inertia of the motor as described above, as long as the timing does not exceed the printing start position of the next line due to the inertia. Detection of the printing start position is not limited to the count value of the rotation pulses of the motor, but may be performed using any other method, for example, the rotation angle of the paper feed roller.

In the embodiment described above, the control circuit itself grasps the printing position and constitutes a means for detecting a predetermined printing position that stops the operation of the motor by itself. In addition to means (for monitoring data transfer), dedicated means for detecting that a predetermined position within a line/dot has been printed using other principles, such as optical or mechanical, may be used. [Effects of the Invention] As explained above, according to the present invention, a means for detecting dot printing at a predetermined position during printing of one line/dot is provided, and the By using the output to stop the operation of the DC motor in the middle of printing one line, it is possible to reliably stop the motor before the printing start position of the next line even if rotation due to inertia of the motor is taken into account. This solves the problem of extra paper feeding and printing in non-standard positions.
A line printer can be realized that uses an inexpensive DC motor for paper feeding instead of an expensive stepping motor.

[Brief explanation of the drawing]

Fig. 1 is a flowchart showing a printing method of a line printer using a conventional DC motor for paper feeding, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. -Q-sr:r: 8-3. (,), (b) are diagrams for explaining the timing of stopping the motor and the printing start position, and FIG. 4 is a flowchart showing an example of an execution program in the control circuit. 1... Control circuit, 2... DC motor, 3...
・Motor drive circuit, 4... Receive buffer, 5...
... Print buffer, 6... Head drive circuit, 7.
...Print head, 8...Print paper. Patent applicant Tamura Electric Manufacturing Co., Ltd. Agent Masaki Yamakawa (Q ≧ 2 people) 10-

Claims (1)

[Claims] The line printer is equipped with a print head composed of one line of dot printing material, and the print head sequentially prints one line of dots on printing paper, and the printing paper is fed by a DC motor. Print position detection means for detecting dot printing at a predetermined position during printing of one line/dot, and print start position detection means for detecting a constant paper feed length of the printing paper and specifying the print start position of the next line. The operation of the DC motor is stopped according to the output of the printing position detection means to print the remaining dots, and the operation of the DC motor is started upon completion of receiving the print data of the next line. A printing method for a line printer, characterized in that printing of the next line is started based on the output of a printing start position detection means.