JPH0335562Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Technical field of the invention The invention relates to printing devices such as dot printers, and is particularly concerned with printing devices in which multiple sheets of recording paper are stacked, with carbon paper sandwiched between them, or so-called non-carbon paper is stacked. The present invention relates to a printing apparatus that uses copy paper and is configured to perform recording and can simultaneously obtain a copy of recording paper.

(b) Prior art and problems FIG. 1 is a schematic explanatory diagram of a conventional printing device.

FIG. 1 shows a type of printing device in which recording paper is pushed into a printing section. In the figure, 1 is a housing, 2 is a print head, 3 is a paper feed platen, 4 is a copy paper 5 is a tractor for conveying the copy paper 4, 6 is a paper guide, and 7
is a bail roller which guides and discharges the copy paper 4 after printing to the outside of the housing 1 by coming into contact with the platen 3. Further, the copy paper 4 is made of two or more sheets stacked one on top of the other, and is stacked by bending the protrusions that protrude alternately at the edges of the paper, and is further provided with perforations that can be cut into a predetermined size. ing.

In the above-mentioned configuration, the print head 2 is reciprocated along the axial direction of the platen by a carrier (not shown), and at the same time, the wire pin (not shown) of the print head 2 is driven based on information from the host device, thereby printing the copy paper. 4 and an ink ribbon (not shown) is struck to print on the copy paper 4.
Every time one line of printing is completed, the tractor 5 and platen 3 are driven to change the copy paper 4.

At this time, the copy paper 4 is quite thick because it is made up of multiple sheets of recording paper stacked on top of each other, and when it is conveyed by the cylindrical platen 3,
There is a difference in paper feed amount between printing paper and copy paper.

That is, as shown in FIG. 2, the outer paper and the inner paper have different circumferential diameters, resulting in a difference in paper feeding speed between the two.

Due to this paper feeding speed difference, the inner paper is not fed, and the inner and outer paper slots are misaligned between the tractor 5 and the paper feeding platen 3, resulting in a paper jam. Further, when printing on a slip or the like on which a predetermined format is printed, printing misalignment occurs.

This becomes more noticeable as the wrapping angle θ of the copy paper 4 around the platen 3 becomes larger.

For this reason, as shown in FIG. 3, another tractor 5 is provided, and the transport path of the copy paper 4 in the portion of the platen 3 facing the print head 1 is kept in a nearly straight line, that is, the wrapping angle around the platen 3 is adjusted. By creating a state in which θ is small, the difference in feeding speed between the inner and outer sheets is reduced, and paper misalignment is eliminated.

However, since the copy paper after printing is normally discharged to the rear of the housing 1 of the printing device, it is necessary to bend the copy paper backward by the guide 8.

Therefore, since the copy paper 4 is bent at the bending portion 8a of the guide guide 8, a speed difference occurs between the inner and outer sheets at this portion, and the guide guide 8
The paper on the inside (the side that contacts the guide 8) becomes slack at the bent portion 8a. As the copy paper 4 is conveyed, since the guide 8 is a flat plate, the slack gradually grows and reaches the bail roller 7, causing a jam in the printing section.

Furthermore, even if a jam does not occur in the printing section, since the guide 8 is a flat plate, the sagging portion is squeezed at the folded portion 8a, where there is no place to escape, and the sagging portion is squeezed at the perforation of the paper. The disadvantage is that the paper inside is folded.

(c) Purpose of the invention The purpose of the invention is to:
It is an object of the present invention to provide a printing device that does not cause paper jams, paper folds, printing misalignments, etc. even when copy paper is used.

(d) Structure of the invention And this purpose is to hit a platen, a bail roller provided to press a recording medium against the platen, and an ink ribbon provided between the platen and the recording medium. A print head that prints on a recording medium, a supply means that is provided upstream of the platen in the conveyance path of the recording medium and supplies the recording medium to the platen, and guides the recording medium on which printing has been performed. The printing device includes a guide, and is configured such that the platen and the print head are arranged opposite each other, the guide guide moving the conveyance path of the recording medium that has passed the contact position of the bail roller in a straight line. and configured to form a recessed portion in the intermediate portion,
To provide a printing device characterized in that when a plurality of recording media that can be simultaneously printed by the impact of the printing head are conveyed, the difference in the amount of slack that occurs between the plurality of recording media is held in the recessed part. This is achieved by

(e) Embodiments of the invention Hereinafter, embodiments of the printing device according to the invention will be described in detail with reference to the drawings.

FIG. 4 is a diagram for explaining an embodiment of the printing device according to the present invention.

The difference between the figure and FIG. 3 is that a recess 10 is provided in the guide 9. With the configuration shown in FIG. 4, even if the copy paper 4 is folded and conveyed at the folded part 9a of the guide 9, the inner paper 4' generated at the folded part 9a Since the slack of the paper 4' can be absorbed by the concave portion 10, the slack of the paper 4' does not get into the bail roller 7 due to growth, and it is possible to prevent the occurrence of paper jam and also to prevent misalignment of printing.

In addition, since the recess 10 provides a sufficient escape area for the copy paper 4', the rigidity of the inner copy paper 4 can be maintained sufficiently high, so that when the copy paper 4 is conveyed as printing progresses, the paper The engagement of the perforations and the protrusions on the side edges pushes up and conveys the outer paper at the folded portion 9a of the guide guide 9, thereby preventing the paper from folding in the vicinity of the perforations.

The guide 9 is shaped like a reverse dogleg, but since the paper 4 has sufficient rigidity, when printing starts, the leading edge of the paper advances along the guide 9, and the upper side The paper is bent and conveyed by contacting the guide 11 of the paper.

Further, the guide 11 may not be provided if the guide 9 is disposed slightly to the right in FIG. 4 from the printing section. Furthermore, in this embodiment, the case where the guide guide 9 is in the shape of an inverted dogleg has been described, but the present invention is not limited to this, and a guide roller is provided at the bent portion 9a of the guide guide 9. However, the space in the middle of the paper may not be provided with anything, and the paper may be transported to the guide roller only by its rigidity.

FIG. 5 shows a modification of the printing device shown in FIG. 4.

The difference between the figure and FIG. 4 is that the upper guide 12 is rotatably supported around a shaft 13 in the direction of the arrow shown by symbol A in the figure, and the lower part is brought into contact with the platen 3 during rotation. copy paper 4
The reason is that the cutter 12a is capable of cutting.

By adopting the configuration as shown in the figure, in the state shown in FIG. 5a, the copy paper 4 is guided until it reaches the folded part 9a at the tip of the guide 9, and in the state shown in FIG. 5b. cutter 12a as shown
The copy paper 4 can be cut after printing is completed.

Note that the cutting is performed by the operator pulling down the upper part of the guide 12 toward the print head 2 side.

Further, in FIG. 5a, the guide 12 is fixed by a fixing device (not shown), which is released at the time of cutting.

(f) Effect of the invention As explained above, according to the invention, it is possible to provide a printing device that can prevent paper jams, folds, and misprints even when copy paper is used. can.

[Brief explanation of the drawing]

1 to 3 are diagrams for explaining a conventional printing device, and FIGS. 4 and 5 are diagrams for explaining an embodiment of the printing device according to the present invention. In the figure, 2 is a printing head, 3 is a paper feed platen, 4 is a sheet of paper, 5 is a tractor, 7 is a bail roller, 9, 11, 12 are guides, 9a is a folded portion, and 10 is a recessed portion.

Claims (1)

[Claims for Utility Model Registration] A platen, a veil roller provided to press a recording medium against the platen, and an ink ribbon provided between the platen and the recording medium by hitting the recording medium onto the recording medium. a print head that performs printing; a supply means that is provided upstream of the platen in the transport path of the recording medium and supplies the recording medium to the platen; and a guide that guides the printed recording medium. The printing device is configured such that the platen and the print head are arranged opposite each other, and the guide guide is configured such that the conveyance path of the recording medium that has passed the contact position of the bail roller is on a straight line, and A recess is formed in the recess, and when a plurality of recording media that can be simultaneously printed by the impact of the print head are conveyed, the difference in the amount of slack that occurs between the plurality of recording media is held in the recess. A printing device characterized by: