JPH05169781A - Printer - Google Patents

Abstract

PURPOSE:To eliminate the sticking of paper in a printer performing lap-printing and to miniaturize a printer. CONSTITUTION:When paper is forwardly or rearwardly fed at the time of lap-printing, the rotation of an ink ribbon supply reel 18 is stopped by the ratchet pawl 27 of an ink ribbon 6 and the tension of the ink ribbon 6 is increased by the taking-up operation of an ink ribbon taking-up reel 17 at this time and the tensioned ink ribbon 6 is used as a paper feed guide. Since the ink ribbon 6 is stretched between the paper and a thermal head 2 by this constitution, the sticking of the paper is eliminated and it becomes unnecessary to scale up a printer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper carrying mechanism for carrying paper by a capstan roller system in plotters, line printers and the like.

[0002]

2. Description of the Related Art An example of a color line printer is shown in FIG.

On the left side of the figure is a paper feed section, which is a paper feed case 13 in which paper 5 which has been cut into a predetermined size is stored.
A paper feed roller 14 is disposed above the front end of the sheet. At the time of sheet feeding, the sheet feeding roller 14 rotates in the direction of the arrow B to pull out the sheets 5 in the sheet feeding case 13 one by one and convey them to the printing unit on the right side in the drawing.

The printing section includes a platen 1 and the platen 1
A thermal line head 2 that press-prints a sheet 5 attached to the sheet 5 via an ink ribbon 6 is provided, and the sheet 5 is configured to be conveyed in forward and reverse directions by a pinch roller 4 and a sheet feed roller 3.

When printing, the thermal line head 2 is pressed against the paper 5 via the ink ribbon 6 of a specific color, and the paper feed roller 3 is rotated in a predetermined direction.

Then, each time the printing with the specific color is completed,
The pressure of the thermal line head 2 is released, the next color ink ribbon 6 is cued, and the paper 5 is conveyed in the reverse direction and returned to a predetermined start position. Then, the thermal line head 2 is pressed again, and printing is performed again with another specific color, for example, three colors of yellow, magenta, and cyan.
Make a color print of the color.

[0007]

By the way, in the conventional printer of this kind, it is provided on the thermal line head when returning the paper in the direction opposite to the paper feeding at the time of printing or at the time of paper feeding as described above. The cover part of the drive integrated circuit may be attracted upwards, that is, toward the thermal line head, due to static electricity or the paper naturally curling, and paper jams may occur. Therefore, the amount of movement of the thermal line head when releasing the pressure is increased. For this reason, the height of the mechanism portion is increased, which in turn increases the size of the entire device.

[0008]

In order to solve the above-mentioned problems, a paper carrying means for carrying a paper, an ink ribbon carrying means for carrying an ink ribbon coated with ink, and a paper carried by the paper carrying means. A printing unit for transferring / sublimating the ink of the ink ribbon carried by the ink ribbon carrying unit, and for carrying or carrying the paper to the printing unit in a printer for printing a plurality of colors of ink on the paper. A printer characterized by comprising a tensioning means for applying tension to the ink ribbon when releasing the contact of the printing portion with the ink ribbon in order to reversely feed the ink ribbon. provide.

[0009]

When the paper is fed or returned, the ink ribbon supply reel is stopped from rotating and the take-up reel is driven to apply tension to the ink ribbon. Even if the ink ribbon is attracted to the line head, the ink ribbon linearly guides the thermal line head and regulates the path of the paper.

At the time of printing, the rotation stop of the supply reel is released to convey the paper in synchronization with the paper.

[0011]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a side view showing a state during sheet feeding or sheet returning according to the present invention. The left side in the figure is a sheet feeding section,
A paper feed roller 14 is arranged above the front end of a paper feed case 13 that contains paper 5 that has been cut into a predetermined size. At the time of sheet feeding, the sheet feeding roller 14 rotates in the direction of the arrow B to pull out the sheets 5 in the sheet feeding case 13 one by one and convey them to the printing unit on the right side in the drawing. In the figure, the platen 1 and the thermal line head 2 facing each other form a printing unit. The thermal line head 2 has a large number of heating elements arranged in a line in a direction perpendicular to the plane of the drawing. The thermal line head 2 is rotatably supported by a support shaft 7, and is pressed onto the platen 1 by a cam 9.
A cooling fin 24 is provided on the back surface of the thermal line head 2 for reducing heat accumulation of heat generated during printing, and a cooling fan 25 is arranged above the cooling fin to face the cooling fin.

The platen 1 has a width slightly longer than the entire width of the heating elements in the arrangement direction and is rotatably supported via a platen shaft 10. A paper feed roller 3 and a pinch roller 4 for feeding the paper 5 are arranged on the left side of the printing unit. The paper feed roller 3 is coupled to a drive motor (not shown), and rotates clockwise when feeding or returning the paper (FIG. 1) and counterclockwise when printing (FIG. 2). It is supposed to do. The pinch roller 4 is pressed against the paper feed roller side by a compression coil spring or the like (not shown) so as to sandwich the paper between the rollers.

The ink ribbon 6 is wound around the bobbins 15 and 16 on the take-up side and the supply side. With the bobbins 15 and 16 loaded, the take-up reel 17 and the supply reel 18 are provided.
Are connected to each.

The take-up reel 17 is, as shown in FIG.
It is rotatably supported around a support shaft 24 fixed to the chassis 30, and is joined to a gear 23 via friction plates 25a and 25b urged by a compression coil spring 20,
It is driven by the DC motor 21 via the gear 22.

The supply reel 18 is rotatably supported around a support shaft 31 fixed to the chassis 30, and is connected to the ratchet plate 26. On the other hand, the ratchet pawl 27 is rotatably supported by a support shaft 28 and is urged in the counterclockwise direction in the drawing, and is rotated by a cam 29.

With such a structure, when the paper is fed or the paper is returned, the cam 29 takes the position shown in FIG. 1 as shown in FIG. 1, so that the ratchet pawl 27 is moved to the ratchet plate 26.
, The ink ribbon supply reel 18 is stopped, and the ink ribbon winding motor 21 is driven.
The rotation of the ink ribbon winding motor 21 is driven by the gears 22 and 23.
Is transmitted to the ink ribbon take-up reel 17 via
After the slack of the ink ribbon 6 in the printing portion is removed, the friction plates 25a and 25b (FIG. 3) start to slide out and generate tension.

In this state, the ink ribbon 6 linearly guides the surface of the thermal line head 2. Therefore, when the paper feed roller 3 is rotated clockwise to convey the paper 5, the path of the paper 5 is regulated. And inserted in a predetermined path.

When printing, as shown in FIG. 2, the cam 29 is moved to the position shown in FIG. 2 and the ratchet pawl 27 is released.
The cam 9 presses the thermal line head 2 downward to press it against the platen 1, and the paper feed roller 3 is rotated counterclockwise to carry out printing while the paper 5 is being conveyed.

The cam 9 and the cam 29 are driven by a drive mechanism (not shown).

[0021]

As described above, according to the present invention, since the ink ribbon interposed between the thermal line head and the paper is used as a guide for conveying the paper, even if the paper is curled, the path of the paper is advanced. Are regulated, and it is possible to prevent paper jams.

Therefore, the amount of movement of the thermal line head when the pressure is released can be reduced, and the wasted space for movement can be reduced.

Also, the device can be miniaturized.

[Brief description of drawings]

FIG. 1 is a side view of a sheet transport mechanism of the present invention.

FIG. 2 is a side view showing a state during printing of the present invention.

FIG. 3 is a top view of an ink ribbon winding unit.

FIG. 4 is a side view of a conventional paper transport mechanism.

[Explanation of symbols]

1 Printing Section (Platen) 2 Printing Section (Thermal Line Head) 3 Paper Conveying Means (Paper Feeding Rollers) 6 Ink Ribbon 17 Ink Ribbon Conveying Means (Ink Ribbon Winding Reel) 18 Ink Ribbon Conveying Means (Ink Ribbon Supply Reel) 25 Cooling fan 26 Tensioning means (ratchet plate) 26 Tensioning means (ratchet claw)

Claims (1)

[Claims] 1. A paper carrying means for carrying a paper, an ink ribbon carrying means for carrying an ink ribbon coated with ink, a paper carried by the paper carrying means, and an ink carried by the ink ribbon carrying means. In a printer having a printing unit for transferring / sublimating ribbon ink, and for printing a plurality of color inks on the paper in order to carry the paper to the printing unit or to reversely feed the paper in a direction opposite to the carrying direction, A printer comprising: a tensioning unit that applies tension to the ink ribbon when the contact of the printing unit with the ink ribbon is released.