JP2824432B2 - How to drive a serial printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a serial printer.

[0002]

2. Description of the Related Art In a conventional serial printer, bidirectional printing is usually performed using a pulse motor. In order for the print head to be able to print, it is necessary to be driven at a stable constant speed by the drive pulse t0 as shown in FIG. It is necessary to supply the rising pulses t1, t2,... To gradually accelerate the print head to a constant speed, and to stop the print head being driven at a constant speed so as not to lose synchronization. , Falling pulse t11,
It is necessary to supply t12 and gradually reduce the speed. The rising pulse needs more pulses than the falling pulse. Therefore, in the case of unidirectional printing from left to right, an approach range b by a rising pulse is provided on the left side of a printable range a by a driving pulse, and a braking range c by a falling pulse is provided on the right side. In the case of bidirectional printing, a run-up range b by a rising pulse is provided on both left and right sides of the printable range a.

[0003]

In the conventional driving method as described above, as shown in FIG. 5, the travel range L0 of the print head required for unidirectional printing is L0 = a + b + c. Since the traveling range L1 of the print head required for bidirectional printing is L1 = a + 2b, bidirectional printing is required to be wider by the traveling range .DELTA.L = bc than unidirectional printing, and the apparatus becomes large. Therefore, if one-way printing with a narrow travel range is adopted to reduce the size of the apparatus, there is a problem that a long printing time is required.

An object of the present invention is to reduce the size of an apparatus without significantly lowering the effective printing speed.

[0005]

In order to achieve the above object, a driving method for a serial printer according to the present invention sets a travel range of a print head to L0, and sets a unidirectional printable range at this time to a, and a When the range that can be printed is d and the range that is outside the range d of bidirectional printing and within the range a that can be printed in one direction is ΔL, printing is performed when the data to be printed is included in the range ΔL. The method is set to one-way printing, and when the data to be printed is not included in the range ΔL, the printing method is set to bidirectional printing.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the driving method according to the present invention, the running range of the carriage of the serial printer is set to L0 as shown in FIG. When printing unidirectionally from the left side to the right side in this travel range L0,
It is the same as in the related art that a running range b by a rising pulse and a braking range c by a falling pulse are required on the left side of the unidirectional printable range and on the right side. Therefore, the unidirectional printable range is L0-bc = a. In addition, in order to perform bidirectional printing in this traveling range L0, a run-up range b by a rising pulse is required on each of the left and right sides of the bidirectional printing possible range. Therefore, the bidirectional printable range is L
0-2b = d, and the bidirectional printable range d is smaller than the unidirectional printable range a by bc = ΔL.

Therefore, in the driving method of the present invention, as shown in FIG. 1, at the time of printing, first, print data is included in a range ΔL which is outside the range of the bidirectional printable range d and within the range of the unidirectional printable range a. Is determined (step 1). If it is included, the printing method is set to one-way printing (step 2), and printing is performed from left to right (step 3). By this printing drive, printing of print data in the same range as the conventional printable range a is possible.

If the print data is not included in the range ΔL and is within the bidirectional printable range d, the print method is set to bidirectional print (step 4), and the print method is set from the side closer to the current position. (Step 3).
This printing drive makes it possible to increase the printing speed.

The operation for printing will be described in detail with reference to FIG. When starting the printing of the first line, it is determined at position A whether or not the printing data of the first line is within the range ΔL. In this case, since it is not within the range ΔL, bidirectional printing is set, and the print head runs from the left end of the first row to the right end of the first row, and printing is performed. After printing of this line is completed, it is determined whether the print data of the second line is within the range ΔL at the position B. In this case, since it is within the range ΔL, one-way printing is set, and the print head once moves to the left, and then prints the second line from the left end to the right end.
After the printing of the second line is completed, the print data of the third line is determined at the position C in the same manner as described above. Here, unidirectional printing is set,
The third line is printed from the left end to the right end. Next, the print data of the fourth line is determined at the D position, and bidirectional printing is set, and printing is performed from the position near the D position, that is, from the right end to the left end of the fourth line.

Next, FIG. 3 shows an example in which the print data of all the lines are within the range d but not within the range ΔL, and the print data of the first line is not within the range ΔL at the position E as described above. Therefore, bidirectional printing is set, and the print head runs from the left end to the right end of the first row, that is, from the left end of the first row, to perform printing. At the F position, since the print data of the second line is not within the range ΔL, bidirectional printing is set, and printing is performed from the right end to the left end of the second line. Similarly, printing is performed from the left end to the right end of the third line based on the determination at the G position, and printing is performed from the right end to the left end of the fourth line based on the determination at the H position. The printing is performed from the right end to the left end of the fifth line based on the determination at the I position, and finally, from the left end to the right end of the sixth line based on the determination at the J position. Printing is performed.

It is also possible to provide the position of the range ΔL on the left side of the range d. In this case, it is set so that printing is performed from right to left in the case of one-way printing, and in the case of bidirectional printing. What is necessary is just to set so that it may print from the end near the current position.

In this manner, the print speed is improved by determining the range of the print data for each line and setting bidirectional printing as much as possible. Also, the unidirectional printing is set only when the print data is out of the range in which bidirectional printing is possible, thereby narrowing the travel range of the print head.

[0013]

As described above, according to the driving method of the present invention, before printing, the range of print data is determined to set one-way printing or two-way printing.
Bidirectional printing can be performed without making the print head travel range wider than the conventional print head travel range for unidirectional printing, enabling printing in a narrow travel range and achieving a compact device. Printing time can be shortened as compared with the case of one-way printing.

[Brief description of the drawings]

FIG. 1 is a flowchart at the time of a printing operation in a driving method of the present invention.

FIG. 2 is an explanatory diagram showing print data and the movement of a print head.

FIG. 3 is an explanatory diagram of another example showing print data and movement of a print head.

FIG. 4 is a diagram illustrating a relationship between a traveling distance and a traveling speed of a print head according to the driving method of the present invention.

FIG. 5 is a diagram illustrating a relationship between a traveling distance and a traveling speed of a print head according to a conventional driving method.

FIG. 6 is a relationship diagram for explaining a traveling distance and a traveling speed of a print head corresponding to a rising pulse, a driving pulse, and a falling pulse of a driving motor.

[Explanation of symbols]

L0 Run range of print head a Unidirectional printable range d Bidirectional printable range ΔL Range outside bidirectional printable range d and included in unidirectional printable range a

Claims (1)

(57) [Claims] 1. A travel range of a print head is set to L0,
At this time, the one-way printable range is set to a, the bidirectional printable range is set to d, and when the range outside the bidirectional printable range d and within the one-way printable range a is set to ΔL, printing should be performed. When the data is included in the range ΔL, the printing method is set to one-way printing, and when the data to be printed is not included in the range ΔL, the printing method is set to bidirectional printing. How to drive a serial printer.