JP3036133B2 - Printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a paper discharge section of a printer.

[0002]

2. Description of the Related Art A printer to which the present invention is applied is a wire dot printer which uses a cut sheet and a continuous form as paper as shown in a side view of FIG. It is supplied to the front and feed roller 3
Is sent to the printing unit 4.

On the other hand, the continuous form 5 is supplied from the lower part of the apparatus, and is sent to the printing unit 4 at the upper part of the apparatus by a tractor 6. After all of the sheets are printed by the printing unit 4, the sheet is discharged from the discharge port 7 at the top of the apparatus.

The printing unit 4 includes a print head 8 and a roll-shaped platen 9 opposed to the print head 8 with a gap therebetween. A bail roller 10 for pressing a sheet against the platen 9 is provided above the platen 9. ing.

[0005] The paper fed to the printing unit 4 is a platen 9
Line feed is discharged by the rotation of. The ejected sheet is guided by the leading end of the sheet abutting against the guide portion 11 as shown in the enlarged side view of FIG.

Although the paper is slightly curled by the platen 9, since the bail roller 10 is located close to the print head 8, it is assumed that the paper is curled in the opposite direction by the guide 11 because it is far from the guide 11. The amount is too small.

In FIG. 3, reference numeral 12 denotes a carrier on which the print head 8 is mounted and moves in parallel with the platen 9, and reference numeral 13 denotes a gap (head gap) between the tip of the print head 8 and the platen 9. An eccentric shaft 14 is a paper guide for sending a continuous form to the printing unit 4.

[0008]

In such a printer as described above, there is a continuous form for copying in which a plurality of sheets are stacked on a continuous form for copying.

When a continuous form for copying is wound around a platen in a printing unit, interlayer slippage occurs between the inner circumferential side and the outer circumferential side due to the difference in circumferential length. Then, this appears as a printing shift, which is particularly problematic, for example, when printing is performed on a ruled line.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent a printing shift due to an interlayer shift of a plurality of stacked sheets.

[0011]

According to the present invention, FIG.
As shown in the enlarged side view of the main part of Fig.
The distance between the bail roller 10 and the guide portion 11 is reduced according to the thickness of the platen 15, and the platen 9, the bail roller 10 and the guide portion 11 are reduced.
The curl amount in the direction opposite to the curl of the paper 15 formed by the platen 9 in the direction opposite to that of the platen 9 is increased.
Is moved in conjunction with the head gap adjusting mechanism so that the bail roller 10 approaches the guide portion 11 when the head gap is increased.

[0012]

When a sheet of a plurality of stacked sheets is wound on a platen, a gap between layers occurs between the inner peripheral side and the outer peripheral side due to a difference in circumferential length.

[0013] In addition, there is a tendency that a lift occurs between the layers to further increase the displacement. It is known that this is reduced by curling the paper in a direction opposite to the direction in which the paper curls due to the platen.

The amount of reduction is proportional to the amount of curl.
Therefore, by bringing the bail roller closer to the guide portion along the paper on the platen, the curl amount of the guided paper is increased, and the interlayer displacement is reduced.

Further, by linking the movement of the bail roller with the head gap adjusting mechanism, when the head gap is increased, the bail roller automatically approaches the guide portion.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, as shown in the enlarged side view of the main part of FIG. 1, a plurality of stacked sheets (continuous form for copying) 15
The bail roller 10 is moved closer to the guide part 11 according to the thickness of the bail, and the distance between the bail roller 10 and the guide part 11 is reduced,
The curl amount of the paper 15 formed by the platen 9, the bail roller 10, and the guide portion 11 in the direction opposite to the curl of the sheet 15 formed by the platen 9 is increased.

As described above, even if the curl in the direction opposite to the curl of the platen 9 is given to the paper 15 to reduce the gap between the layers, a constant curl amount is always provided regardless of the number of stacked papers. By doing so, the effect of interlayer misalignment is small and, for example, when one sheet is used, it causes a jam.

Therefore, in the present invention, the curl amount is changed according to the number of sheets to be stacked. The method of moving the bail roller 10 is performed in conjunction with a head gap adjusting mechanism as shown in the side view of FIG.

That is, as described in the related art, the adjustment of the head gap is performed by rotating the eccentric shaft 13. Adjustment lever fixed to the eccentric shaft 13 rotates the eccentric shaft 13
This is done by manually rotating 16.

The adjusting lever 16 shown in the figure is located at a position where the head gap is minimized. When the adjusting lever 16 is now rotated counterclockwise, the head gap is operated to increase. The rotation of the adjustment lever 16 is fixed by a click stopper 17 with which the rear end of the adjustment lever 16 slides in a pressed state.

When the adjustment lever 16 is rotated, the slider at the lower end of the L-shaped lever 19 rotatably fixed at the fulcrum 18 slides inside the groove 16a of the adjustment lever 16, and the lever 19 is rotated. Is rotated counterclockwise, and a torsion spring (not shown) is provided at the upper end.
Urges the swinging arm 20 which is urged clockwise and is rotatably fixed, and guides the bail roller 10 rotatably fixed to the tip of the swinging arm 20 along the platen 9. Department
Move in 11 directions.

At this time, the bail roller 10 is urged by a torsion spring via the swing arm 20, and moves while pressing the paper 15 wound around the platen 9 as shown in FIG. The rotation of the adjustment lever 16 is performed in accordance with the thickness of the sheet 15, and the head gap amount is increased when the thickness of the sheet 15 is large.

Then, the bail roller 10 interlocks with this,
From the position indicated by the two-dot chain line shown in FIG.
As described above, as the diameter of the arc of the sheet 15 becomes smaller (the curl amount increases), the lifting between the stacked sheets decreases, and the interlayer shift decreases.

[0024]

According to the present invention, it is possible to prevent a printing shift due to an interlayer shift of a plurality of stacked papers, which has a great industrial effect.

[Brief description of the drawings]

FIG. 1 is an enlarged side view of a main part of a printer according to the present invention;

FIG. 2 is a side view of a bail roller moving mechanism,

FIG. 3 is a side view of a printer to which the present invention is applied;

FIG. 4 is an enlarged side view of a conventional paper discharge mechanism.

[Explanation of symbols]

4 printing section, 7 outlet, 8
Print head, 9 platens, 10 bail rollers
LA, 11 guides, 12 carriers,
13 Eccentric shaft, 15 papers (continuous form for copying), 16 adjustment lever, 17 click stopper, 18 fulcrum, 19 lever,
20 swing arm,

Claims (2)

(57) [Claims] 1. A bail roller (10) located above a platen (9) and pressing a sheet to be ejected against the platen (9), and is fed by the platen (9) and the bail roller (10). Guide section for guiding the paper to be fed to the upper discharge port (7)
(11), the distance between the bail roller (10) and the guide portion (11) is reduced according to the thickness of the paper (15) in which a plurality of sheets are stacked, and the platen (9) The platen (9) of the paper (15) formed by the bail roller (10) and the guide portion (11)
A printer characterized in that the amount of curl in the direction opposite to the direction of curl caused by is increased. 2. The movement of the bail roller (10) according to claim 1,
A printer characterized in that the bail roller (10) is brought closer to the guide portion (11) when the head gap is increased by interlocking with a head gap adjusting mechanism.