JPH0263878A - Paper feed apparatus of printer - Google Patents

Abstract

PURPOSE:To well perform paper feed by constituting the title apparatus so that printing paper is delivered in a state bent in the direction reverse to a bending direction generated when said paper is wound around a platen to be bent. CONSTITUTION:Papers 101, 102 are mounted on a tractor 2 to be fed and further wound around a platen 1 by a paper bail roller 4 to obtain paper feed force from the platen 1 and, therefore, said papers 101, 102 issued from the tractor 2 are smoothly fed without generating slackening in a paper route 9. The papers 101, 102 are bent along the platen 1 by a curved surface of a circular arc ab and guided to a paper guide member 8 to be bent along the paper bail roller 4 by a curved surface of a circular arc bc. The shift of the papers 101, 102 is generated on the circular arcs ab, bc but the paper shift on the circular arc ab is reverse to that on the circular arc bc in a shift direction and both paper shifts are set off by the passage of the papers on the circular arcs ab, bc. As a result, the error of a printing position due to paper shift is eliminated and multilayer superposed printing papers can be fed at a printing interval of good accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a printer, and more particularly, to a printer that feeds multiple layers of printing paper.

[Prior art 1] Conventionally, a printer that feeds paper by wrapping it around a cylindrical platen has a driven roller that comes into elastic contact with the platen, and the platen is rotated by a constant angle by a drive source such as a motor. On the other hand, the driven roller is brought into elastic contact with the peripheral surface of the platen by an elastic biasing means such as a spring. The printing paper is held between the platen and the driven roller, and is fed by the frictional force between the platen and the driven roller. The printing paper is held at a predetermined position during times other than the feeding stroke. By the way, as printing paper,
When using continuous paper having feed holes such as Fonfold paper, a paper conveyance device consisting of a sprocket or a tractor is used, as shown in Japanese Utility Model Publication No. 145048/1983.

Problem to be Solved by the Invention 1 As shown in FIG. 5, when multiple layers of printing paper are wound around a cylindrical platen and fed,
There is a difference in distance from the center of the platen between the printing paper 102 and the printing paper 102 which is the bottom paper. This is due to the thickness of the paper, and the greater the number of sheets stacked in multiple layers, the greater the difference. There will be a slight difference in the amount of feed that is applied.If the gluing part of multiple layers of printing paper is strong enough, for example, if the paper is glued together, the paper will not shift, and the paper will not shift. The stacked sheets are fed by the same amount on both the top and bottom.However, if the bonding of the joined parts is insufficient, for example, the press machine has added gears to the paper, and the top and bottom papers are held together by the gears. In such a case, due to the difference in the amount of feed given to the upper and lower sheets, the bonded portions of the upper and lower sheets will peel off, and paper misalignment will occur between the printing paper 101 and the printing paper 102.

If this paper misalignment accumulates, the printing position will shift between the upper and lower sheets of paper.Furthermore, when paper is fed using a conventional push-type tractor, if significant paper misalignment occurs in the tractor unit, This results in poor engagement between the paper feed hole and the paper feed hole, resulting in a problem of paper feed failure. Compared to pull-up tractors, push-in tractors have a platen that works to shift the paper even after it is removed from the tractor.
Paper misalignment is likely to occur.

The purpose of the present invention is to eliminate such drawbacks of the prior art,
Without sacrificing the advantages of push-in tractors, such as ease of paper insertion and the ability to print from a short distance from the edge of the paper, the simple paper guide shape prevents misalignment of multi-layered paper. It is an object of the present invention to provide a paper feeding device that solves problems caused by paper misalignment and enables good paper feeding.

[Means for Solving the Problems] In order to solve the above-mentioned conventional problems, the present invention provides a cylindrical platen, a paper bail roller that wraps and holds printing paper around the platen, and the paper bail roller. and a paper guide member for discharging the print paper that has passed through the platen. do.

[Function] According to the above configuration of the present invention, as shown in FIG. 1, although the multilayer printing paper wound around the platen is bent on the curved surface of one circular arc ab, paper deviation occurs; Since the windings around the roller are bent in opposite directions, the direction of paper shear in arc bC is opposite to the direction of paper shear in arc ab, so the respective paper shears cancel each other out. That is, the multilayer printing paper has a circular arc ab
, the paper misalignment will not accumulate by passing through the circular arc bc.

[Examples] Examples of the present invention will be described below with reference to one drawing. FIG. 1 is a side sectional view of a printer according to an embodiment of the present invention, FIG. 2 is a side view showing a portion of the printer, and FIG. 3 is a top view of the printer.

1 is a cylindrical platen, and 2 is a push-type tractor. 3 is a power transmission section that drives the platen 1 and the tractor 2. A roller shaft 5 passes through the paper bail roller 4, and the roller shaft 5 is supported by an arm 6.

The arm 6 uses the fulcrum hole 6a as a fulcrum and is applied with the elastic force of a spring 7, thereby pressing the paper bail roller 4 against the platen 1. 8 is a paper guide member according to the present invention. 101 is the top paper of the multilayer printing paper; 10'
2 is the bottom sheet of the multilayer printing paper.

Paper 101 and paper 102 are mounted on the tractor 2,
Since the paper is fed and further wrapped around the platen l by the paper bail roller 4, the paper feed force is obtained from the platen l. Therefore, the paper 10 after leaving the tractor 2
1 and 102, the paper is fed smoothly (without sagging) in the paper path 9.

The sheets 101 and 102 are first bent along the curved surface of a circular arc ab along the platen 1, then guided to the paper guide member 8, and bent along the curved surface of the circular arc bc along the paper bail roller 4. In the arc bc, the paper deviation between the paper lot and the paper 102 is a paper deviation in the opposite direction,
By passing through arcs ab and bc, the paper misalignment is canceled out.

10 is a print head, and printing is performed at the P position of the opposing platen 1. Paper 101 and paper 10 at P position
2 is bent by the curved surface of the platen, so slight misalignment may occur, but the amount of misalignment does not accumulate, so the printed line intervals on paper 101 and paper 102 are the same, If the paper feed is constant, the print line spacing will also be constant.

Now, in 1 and above, we have described an example in which paper is fed by a push type or a tractor in a printer that has a cylindrical platen and a paper bail roller, but it is also possible to use a blink printer that does not have a cylindrical platen or a paper bail roller. When paper is fed by bending multilayer paper, paper misalignment occurs 6.
An embodiment to which the principle of operation according to the present invention is applied to a printer having a flat platen and frictionally feeding paper will be described with reference to FIG.

11 is a flat platen, which is connected to a discharge paper guide member 11a. Reference numeral 12 denotes a paper feed roller made of rubber, and reference numeral 13 denotes a pressure roller that presses the print sheets 101 and 102 against the paper feed roller 12. The print sheets 101 and 102 are fed by the rotation of the paper feed roller 12.

The print sheets 101 and 102 are wrapped around the sheet feed roller 12 and fed while being bent, causing a sheet shift, but they are bent in the opposite direction by the discharge sheet guide 11a. By bending in the opposite direction, the misalignment of one sheet is corrected, and on the flat platen 1, the printing intervals of printing paper lot and 102 are the same, and if the feeding of the paper feed roller is constant, the printing interval is also constant. .

[Effect of the invention 1 As described above, according to the present invention, the paper misalignment that occurs when feeding multi-layer printing paper can be avoided by adopting a very simple paper ejection method of bending the printing paper after printing. ,
Suppressing paper misalignment means that it can be corrected.
It is possible to provide a printer that can feed multi-layered printing paper with no errors in printing position due to paper misalignment and with good printing interval accuracy. In particular, in printers where paper is fed by a push-type tractor, paper misalignment can lead to poor engagement between the tractor's bin and the printing paper feed hole, which can lead to paper feed failure, which can be a major problem. By implementing measures to prevent paper misalignment, the problem of poor paper feeding caused by this paper misalignment can also be solved.

It is a side sectional view of a link.

FIG. 5 is a side sectional view of a conventional printer.

2・ 4・ 8・ 10・ 1　　・ 1'la 101・ ・Platen ・Tractor ・Paper bail roller ・Paper guide member ・Print head ・Flat platen ・Output paper guide ・Print paper ・Print paper that's all

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a printer according to the present invention, FIG. 2 is a side view showing a part of the printer, and FIG. 3 is a top view of the printer. FIG. 4 shows another embodiment of the present invention by the applicant.
Seiko Epson Corporation

Claims (1)

[Claims] A printer that has a cylindrical platen, wraps printing paper around the platen, and feeds the printing paper by rotating the platen, a paper bail roller that presses the printing paper against the platen; and a paper guide member that discharges the printing paper that has passed through the paper bail roller, and the paper guide member bends the printing paper in the opposite direction to the bending direction in which it is bent after being wrapped around the platen, and then the paper is discharged. A paper feeding device for a printer, characterized in that: