JP2735421B2 - Line 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 line printer.

[0002]

2. Description of the Related Art FIG. 2 is a perspective view of a conventional dot impact type line printer, in which a paper 2 travels on a platen 1 and a paper detection sensor 6 detects the paper 2.
In response to this signal, the line head driver 9 drives the line head 3 and prints on the paper 2 with the print pins 4. As shown in FIG. 6, in a conventional line printer, a user who uses only a narrow paper 2 such as a slip uses only the printing mechanism on the left side of the line head 3 and does not use the printing mechanism on the right side at all. I didn't.

[0003]

The above-described conventional dot impact type line printer uses only a sheet (for example, 5 inches) with a narrow sheet width (for example, 5 inches) as a slip even though the print area is 13.6 inches. In
Only the left side print mechanism of the line head with multiple print mechanisms in the horizontal direction is used, and the right side print mechanism which is the opposite side is not used at all, so all the print mechanisms of the line head are not effectively used and expensive Had to be replaced in a short cycle.

[0004]

Means for Solving the Problems The dot impact of the present invention
The line printer has two or more sheet detection sensors arranged at positions shifted in the lateral direction of the sheet, and a shift circuit for shifting the first printing position in conjunction with the sheet detection sensors.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIGS. 1 and 2 are a side view and a perspective view, respectively, of an embodiment of the present invention.

First, in FIG. 1, a paper 2 is wound around a platen 1 and an ink ribbon 5 (not shown in FIG. 2) so that a print pin 4 of a line head 3 faces the platen 1. It is located between.

Further, the paper detection sensor 6 and the paper detection sensor 7 are arranged so as to be shifted in the width direction of the paper 2.

The sheet detection sensor 6 and the sheet detection sensor 7 are connected to a shift circuit 8,
Are connected to a line head driver 9.

Further, the line head 3 is connected to a line head driver 9.

Next, the mechanism of the line head 3 will be described with reference to FIG.

First, the upper yoke 10 is connected to the base yoke 1
1 vertically attached to one end of the upper yoke 10
Is wound around the coil 12. A magnet 13 is attached to the base yoke 11 on the opposite side of the same surface on which the upper yoke 10 is attached, and a lower yoke 14 is attached to the other end of the magnet 13.
Are vertically attached to the magnet 13.

A print pin 4 is attached to a free end of a leaf spring-shaped armature 15, and the other end of the armature 15 is attached to a lower yoke 14.

A plurality of (for example, 84) printing mechanisms as described above are arranged in the longitudinal direction of the platen 1.

Next, the operation of the printing mechanism of the print head 3 will be described with reference to FIG.
I will explain using.

Normally (when not in operation), the armature 15 is bent by the magnetic force of the magnet 13 as shown in FIG. Next, when a current is applied to the coil 12 in accordance with a print command, the magnetic flux generated from the coil 12 cancels the magnetic flux flowing from the magnet 13 to the upper yoke 10, and the armature 15 leaves the upper yoke 10 by elastic force. Move in the direction. The printing pins 4 joined to the free ends of the amateurs 15 strike the ink ribbon 5 and print dots on the paper 2.

After that, when the current of the coil 12 is cut off, the armature 15 is attracted to the upper yoke 10 again.

Printing is performed while repeating the above operations.

Next, the overall operation of this embodiment will be described.

Here, when the sheet detection sensor 6 and the sheet detection sensor 7 detect the sheet 2, ON is set, and when there is no sheet and no sheet is detected, OFF is set. Paper detection sensor 6 is O
When N, the first printing position is from the left end, and when only the paper detection sensor 7 is ON, the first printing position is set at the center.

As shown in FIG. 2, the print pins 4 of the line head 3
In the case of paper 2 in which it is necessary to print using almost the entire length from end to end, the paper detection sensor 6 and the paper detection sensor 7 are both turned on, the shift circuit 8 does not operate, and the line head driver 9 According to the command, the left end is printed as the first print position.

Next, as shown in FIG. 3, when the narrow paper 2 of the paper width is skewed to the left, the paper detection sensor 6 is turned on and the paper detection sensor 7 is turned off, and the left end is similarly printed as the first print position.

Next, when the paper 2 is printed with the right side as shown in FIG. 4, the paper detection sensor 6 is turned off, the paper detection sensor 7 is turned on, and the first printing position is shifted from the left end to the center by the shift circuit 8. The line head driver 9 prints with the print pins 4 on the right half of the line head 3.

Next, when the paper 2 is not detected by the paper detection sensor 6 and the paper detection sensor 7 as shown in FIG.
Will not be printed.

[0025]

As described above, according to the present invention, two or more sheet detection sensors arranged at positions shifted in the lateral direction of a sheet and a shift circuit for shifting the first printing position in conjunction with the sheet detection sensors. With this configuration, when the paper width is narrow, the first printing position can be shifted to the right by setting the paper position to the right with respect to the platen. Can be effectively used, and the life of an expensive line head can be extended nearly twice.

In the past, when a failure occurred in the printing mechanism on the left side of the line head (broken print pins, burned coils, etc.), it was unavoidable to interrupt the work until the repair of the device was completed. By shifting the paper position to the right and using the right printing mechanism where no trouble occurs, the work can be continued without interrupting the work.

[Brief description of the drawings]

FIG. 1 is a side view of one embodiment of the present invention.

FIG. 2 is a perspective view of the embodiment shown in FIG.

FIG. 3 is a perspective view of the embodiment shown in FIG. 1 in which narrow paper is set on the left side.

FIG. 4 is a perspective view of the embodiment shown in FIG. 1 in which narrow paper is set on the right side.

FIG. 5 is a perspective view of the embodiment shown in FIG. 1 in a state where sheets are not set.

FIG. 6 is a perspective view of a conventional line printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Platen 2 Paper 3 Line head 4 Print pin 5 Ink ribbon 6 Paper detection sensor 7 Paper detection sensor 8 Shift circuit 9 Line head driver 10 Upper yoke 11 Base yoke 12 Coil 13 Magnet 14 Lower yoke 15 Amateur

Claims (1)

(57) [Claims] 1. A sheet detection sensor having two or more sheet detection sensors which are displaced in the width direction of a sheet and a signal received from the sheet detection sensor, the line is detected when a sheet is detected in the left half of a print area of a line head. When the left end of the print area of the head is the first print position and the paper is detected in the right half without detecting the paper in the left half of the print area of the line head, the center of the print area of the line head is defined as the first print position. A line printer comprising: