JPS5889387A - Paper feed mechanism - Google Patents

Abstract

PURPOSE:To send papers toward both normal and reverse directions without slackening by providing a roller which turns with a peripheral speed faster than the feeding speed of papers when papers are sent in the normal direction but gives a friction force to papers without rotation when papers are sent in the reverse direction. CONSTITUTION:A pinch roller 2 pushes a platen 4 through a usual paper 1 by its strong force, and another pinch roller 3 pushes a rubber roller 11 through the usual paper 1 by its weak force. In sending papers in the normal direction A, since the rubber roller 11 turns with a faster peripheral speed than the platen 4, the usual papers are given tension between the contact points 20 and 21 and sent at a sending speed set by the platen 4. In sending papers in the reverse direction, the ruber roller 11 does not turn by an one-way clutch and thereby the paper 1 is sent out while being given a friction force. Even in the case of perforated papers, in the same way, they are given tension between the pin feed roller 8 and the rubber roller 11 and sent out without slackening.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an F1 paper feeding mechanism, and more particularly to a paper feeding mechanism that can feed sheets in both forward and reverse directions without slack.

Generally speaking, printers use two types of paper.

That is, paper without holes (regular paper) that does not have special holes for paper feeding, such as rectangular or square cut sheets or roll paper containing long paper, and
Note that in the case of perforated paper, there are perforations at regular intervals, where it is folded back and folded into fan-hold paper and rolled into a roll.
There is paper with holes. FIGS. 1 and 2 show a paper feeding mechanism that is equipped with friction paper feeding means and bin feed paper feeding means and is capable of feeding both pass-through paper and perforated paper.

FIG. 1 shows the case of feeding the plain paper 1, in which the plain paper 1 is pressed against the plain platen 4, which is the friction paper feeding rollers 2 and 3d of the friction paper feeding means. The pinch roller 2 is pressed with a strong force to obtain a large driving force. I'm being pushed by. FIG. 2 is a diagram showing the case of feeding the perforated paper 7, in which the pinch ruler 2#'i is released from pressure contact with the platen 4 by a release lever (not shown).

However, the pinch roller 3 is completely different from the case of ordinary paper,
It is in contact with the platen 4 via a perforated paper sheet. With a 9-paper force vine, make the tip of the tooth face the distance 111 of 7 from the front surface of the head 6 to ψ. The platen number and the bin feed roller 8 of the pin feed paper feeding means always operate in conjunction with each other, but the amount of feed by the platen number is always greater than the amount of feed by the bin feed ruler 8. This is because if the feeding amount is kept exactly the same, the perforated paper sheet will sag between the bin feed loaf 8 and the platen 4, and if it is excessively large, the KI/
This is because it may cause a paper jam.

The reason is explained below. The nominal pitch of the bins is usually 1
Since it is 2.7 mm, the hole pitch of the paper is also processed to 12.7 mm, but due to the physical properties of paper, it can easily expand or contract by 0.1 mg due to the influence of temperature and humidity.

If the pitch is 12.6 to 1 to 5, the amount of paper fed by the pin feed roller 8 will be reduced.

On the other hand, the amount of tension a12 depending on the platen number. 'F dew, so between the bin feed roller 8 and the platen 40, the perforated paper 7
is given Tenshi Cao N. However, pinch roller 3#
'111- Since the platen number is pushed with force, the perforated paper 7 slips against the platen 4,
Paper can be sent without any problems. -The large pitch of the paper is 12.8
m, 0.0 per Ktil pitch. It also causes sagging. The amount of 0.1 ≠ is a small amount, but it accumulates, so if 100 pitches are sent, it becomes lO■, which causes a paper jam. Therefore, conventionally, the feed amount by the platen was 100 times larger than the feed amount by the bin feed roller 16.
I set it to a high degree.

With this setting, the hole pitch of the paper will be 1282 feet.
No paper jam occurs even if the paper is stretched to a maximum length. However, if it stretches beyond this point, paper jams will occur, and even if paper with normal dimensions is used, if the feeding pitch is different when using plain paper and perforated paper, there will be disadvantages. there were. In other words, the paper feed by the printer is always 6 inches (4,23fi) or IA inches (6,351 inches).
11) Since the values are standardized as -, when printing on regular paper with this printer, the values differ by about 1% from those of other printers. If this were to be done in 05%, the elongation of the perforated paper would have to be suppressed to within 0.5%, resulting in unusable paper.

In addition, in such a paper feeder, if the paper is fed in the opposite direction, the correct tension is not applied to the paper, which often causes a jam. A#i It is an object of the present invention to provide a paper feeding mechanism that eliminates the above-mentioned drawbacks and can accurately feed paper in both directions of the main gate.

This is the case. Print head (wire tod head)
6#'i Ink ribbon 10 Friction paper feed through plain paper 1 First friction paper feed 9 lower arm of two stages 15fn 4KL
I'm facing it. The bin feed roller 8 is a rubber ruler that forms the pin feed paper feeding means and is the second friction paper feeding roller of the 11Fi friction paper feeding means.

1'lt'i A common pulse motor as shown in Fig.
12. A gear 13 integrated with the output shaft of the pulse motor 12 meshes with a gear 14 and further rotates gears 15 and 16. Here, the platen number and the rotation ratio of the bin feed rollers 8 and 8' are set so that the amount of paper fed by the platen 4 and the bin feed rollers 8 and 8' are exactly the same. By rotating the row, the amount of circumferential movement of both a423■ is obtained. Gear 18 is rotated via gear 15Fi and intermediate gear l. gear 18
Ratchet! A towway clutch 19 is built-in and the pulse motor 12 is used in the forward direction.
For rotation, the rubber roller 11 is rotated, but cannot be rotated Fi in the opposite direction. The rotation ratio when the rubber a-ru 11 rotates in the forward direction is set so that the paper feed amount is about 10% larger than the paper feed amount by the platen 4 and bin feed rulers 8, 8', and the pulse motor 12 For one line of rotation in the positive direction, a circumferential movement of 465 pieces is obtained.

Again in FIG. 3, the pinch roller 2tJ is pushing the platen 4 with a strong force through the plain paper 1; on the other hand, the pinch roller 3tJ is pushing the platen 4 with a very weak force via the plain paper 1. For feeding the plain paper 1 in the forward direction (mu direction), the rubber roller llt; t rotates at a peripheral speed higher than that of the platen 4;
Tension is always applied between the pressure contact point 20 of the platen 4, the rubber roller 11, and the pressure contact point 21 of the pinch roller 3. However, since the pressing force of the pinch roller 3 is set to be much smaller than that of the pinch roller 2, slippage occurs on the rubber field roller 11 side of the normal paper 1#i.

Therefore, the normal paper 1Fi 1 line Tosha is exactly 4.23 in the forward direction.
-Can be sent. Furthermore, even if the paper is set with slack between the pressure contact points 20 and 21 due to this tension, the slack can be removed by slightly feeding the paper, and staining of the paper by the ink ribbon 10 can be prevented.

Also, 1J for feeding the W-way paper l in the opposite direction (B direction).
1 The one-way clutch 19 prevents the rubber roller 11 from rotating and applies frictional force to the paper, so tension is also applied between the press contact points 20 and 21. Also, since the ordinary paper 1 slips on the rubber roller 1 side, the reverse occurs. Ordinary paper 1#'i does not sag even when feeding in the direction, and it is accurate to 4.23 per line.
By feeding paper by only m, it becomes possible to pack-feed a large amount without causing paper jams.

FIG. 4 is a diagram showing the case where the perforated paper 7 is fed.

In this case, the pinch roller 2 is released from pressure contact with the platen 4 by a rally-X lever (not shown).

When the perforated paper 7 is fed in the forward direction (mu direction), the bin feed roller 8.
, 23 ■ are sent out. In this case, the platen 4 does not apply any feeding force to the paper. The rubber roller 11 has a faster peripheral speed than the bin feed roller 8.8' and pulls the perforated paper, so 1. A tensile force is applied to the paper sheet between the point where the bin 285 of the bin feed reeler 8 is locked and the pressure contact point 21.

Since it is likely that the paper leaf with holes will slip against the bin feed rollers 8 and 8', the paper leaf with holes that will not slide against the rubber roller 11 will sag between the locking point of the bin 28A and the pressure contact point 21. The KB is set to such an extent that the perforated paper sheet does not tear from the hole. When paper with holes is fed in the opposite direction, the rubber ruler 11 is not rotated by the one-way clutch 19, so tension is still applied to the paper between the #i pressure contact 21 and the pin 8, and the paper slides against the rubber roller 11 and is accurately 413 ■ Reverse feed.

In this embodiment, a so-called tightening spring clutch may be used as the one-way clutch 19, and in this case, the power of the rubber 0-111t'i pulse motor 12 is not transmitted when paper is fed in the reverse direction. Depending on the motor, it will not rotate, but when the paper is back-fed, it will follow the paper and rotate without rubbing. Also, at this time, the rubber roller 11#i rotates with a slight resistance force, which imparts tension to the paper, but in order to further increase this tension, use other spring means or the like to rotate the rubber loaf 1.
Just limit it to 10 rotations.

#IK6 diagram is another embodiment according to the present invention. In this example, compared to the embodiment shown in FIG. 4, a bin feed reluctor 22 is used as the bin feed member in place of the roller 9. The first roller, which is the feed roller between the feeder and the roller,
The platen 4 also serves as a platen for printing as a friction paper feeding roller, but in the 6th vA embodiment, the platen 23 for printing is a fixed member made of metal and is fed as the first friction paper feeding roller. A roller 24 is provided separately. In the case of perforated paper 7, the pinch roller 2 is released from the p-roller 24, and in the case of plain paper, it is strongly pressed against the roller 24, thereby achieving exactly the same effect as the embodiment shown in FIGS. 3 and 4. It is something that can be demonstrated.

As described above, the present invention has the following effects.

b) The paper feed pitch is uniform and accurate paper feed is possible when using either plain paper or perforated paper.

Ex) Even if perforated paper expands and contracts by more than 1% due to temperature and humidity, paper jams will not occur.

C) Regardless of whether paper with holes or regular paper is used, the paper can be fed in the opposite direction without slack, and no problems occur even when the feed amount is extremely large.

Even if the printing paper is not set properly and there is slack at the printing position, simply feeding the paper forward or backward will remove the slack and eliminate stains on the paper caused by ink ribbons, etc.

FIG. 4 is a cross-sectional view of the paper feeding mechanism when using perforated paper, FIG. 5 is an explanatory diagram of the rotational force transmission mechanism in #i, and FIG. 6 is an explanatory diagram of another embodiment.

1-----1 plain paper, 2, 3-----1 pinch roller, 4, 25-----platen, ? ---1 holed paper, 8-1--bin feed roller, I 0--
Ink ribbon, 11----Rubber roller, 1i----
Pulse motor - 122---Bin feed tratata,
24---One feed p-ra.

L

Claims (1)

[Claims] When paper feed 9 is carried out in the forward direction, it rotates at a circumferential speed that is faster than a predetermined paper feed speed to apply tension to the base paper, and when paper is fed in the reverse direction, it is set to apply friction to the base paper. A paper feeding mechanism characterized by having a roller.