JPH0512254B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to an automatic sheet feeding device for cut sheets in a printer of an office electronic computer, and in particular, the present invention relates to an automatic sheet feeding device for cut sheets in a printer of an office electronic computer, and in particular, the invention relates to an automatic sheet feeding device for a cut sheet in a printer of an office computer. The present invention relates to an automatic paper feeder suitable for certain printers.

2. Description of the Related Art There are various structures of automatic paper feeding devices installed in computer printers, but as shown in FIG. 3, a roller 1 that rotates as a paper separation mechanism is used.
Conventionally, there has been used a device having a structure in which the paper 3 is passed between the paper 3 and the friction pad 2 that comes into contact with the paper 3 to separate the paper.

In general, printers for office computers need to have a structure that allows them to print both continuous form paper and sheet-like cut paper, and in order to make this possible,
As shown in FIG. 3, a structure is adopted in which a paper feed path 4 for continuous sheets and a feed path 5 for cut sheets are arranged one above the other. In Figure 3, 6 is the friction pad 2 that is connected to the roller 1.
7 is a paper tray of the automatic paper feeder; 8 is a front edge guide for the sheets 3 stacked on the paper tray; 10, 11, and 12 are guide plates; 13 is a platen; 14 is a printer The head 15 is a printing section formed between these, and the numerals 16 and 17 are paper feed rollers for cut sheets.

When printing the address etc. on the envelopes, the envelopes 20, which serve as the printing paper 3, are stacked on the paper tray 7 of the automatic paper feeder, and passed through the cut paper supply path 5 to the printing unit 1.
It will be sent to 5th.

What is shown in Fig. 3 is the roller 1 of the paper separation mechanism.
However, in this structure, the paper feed roller 1 is used as the paper feed roller 3.
Since the friction pad 2 needs to be pressed against both the sheet 3 and the friction pad 2, the friction pad 2 is pressed against the paper feed roller 1 in a state oblique to the direction in which the paper 3 enters, and the friction pad 2 The paper 3 that has entered the contact portion is bent slightly upward and sent out.

Problems to be Solved by the Invention However, since the envelope 20 has an overlapping portion 22 glued to the bottom side 21, when the envelope 20 is fed sideways with the automatic paper feeder having the above structure, the paper tray The top surface of the envelopes 20 stacked on top of the envelopes 7 becomes slanted. In general, the paper feed roller 1 is placed at two or more positions A, B, C ( Fourth
In the case of envelopes, the bottom side 21 of the stacked sheets is higher, so the passage of the envelope 20 is blocked by the part of the roller 1C closest to the bottom side. There is a tendency to
Problems have occurred in which the envelopes 20 are fed diagonally or the envelopes 20 get caught on the roller 1C and cannot be fed.

The present invention has been made for the purpose of avoiding the above-mentioned trouble when feeding envelopes in an automatic paper feeder having a paper separation mechanism structured as shown in FIGS. 3 and 4.

-Means for Solving the Problems- In the apparatus of the present invention, a diameter smaller than the paper feed roller 1 is provided on the side opposite to the reference side of the paper to be fed, that is, on the bottom side of the envelope when feeding the envelope horizontally. A pressing roller 32 whose length covers the area where the bottom side 21 of the envelope 20 to be fed is located is attached to the paper feeding roller 1.
The holding roller 32 is mounted coaxially with the paper feeding roller 1, and the holding roller 32 is rotated together with the paper feeding roller 1 when paper is fed. The holding roller 32 is connected to the shaft 30 of the paper feed roller.
The material of the roller may be the same as that of the paper feed roller. Holding roller 3
Specifically speaking, the length of 2 is, for example, if envelopes 20a to 20d of length 4, length 3, corner 3, and corner 2, which are standardized as envelope dimensions, can be automatically fed. When these envelopes are loaded on the landscape paper tray 7, the bottom sides 21a, 21
The length should cover the range where b, 21c and 21d are located.

Operation When the conventional automatic paper feeder having the structure shown in FIG. Since the envelopes 20 are stacked on top of each other, as shown in FIG. 4, the envelopes 20 to be fed are bent into a concave shape at the part 1C of the paper feed roller 1 closest to the bottom of the envelope when paper is fed. Due to this bending, the flexibility of the envelope 20 in the paper feeding direction is impaired at the bent portion 24, and therefore, the contact portion between the friction pad 2 and the paper feed roller 1C, which are in contact with each other at an angle, is 20 becomes difficult to pass through, and as a result, the bottom side 21 is fed out with a delay, resulting in skewed feeding of the envelope.Furthermore, the passage of the envelope at the bent portion is completely blocked, resulting in an inability to feed the envelope.

In contrast, in the structure of the present invention, the presser roller 32 functions to suppress the bottom side of the envelope 20 to be fed from bending and jumping up from the paper feed roller 1C. The bending of the envelope at that part is suppressed to a slight bend, so that the bending stiffness of the supplied envelope 20 in the paper feeding direction does not locally increase, and the bending stiffness of the envelope 20 at the part closest to the bottom side 21 is suppressed to a slight bend. This avoids an increase in paper passage resistance, and as a result, the problems of paper skewing and inability to feed envelopes that conventionally occurred when feeding envelopes can be avoided.

-Embodiment- Fig. 1 is a plan view showing a paper feeding roller portion in an automatic paper feeding device of the present invention, and Fig. 2 is a perspective view showing a state in which envelopes are automatically fed. In the diagram, 1A to 1
C is a paper feed roller, 30 is a paper feed roller shaft, 31 is an auxiliary roller fixed to the paper feed roller shaft 30, 32 is a press roller of the present invention also fixed to the paper feed roller shaft 30, and 20a in FIG. 20d to 20d indicate the types of envelopes that can be fed by the automatic paper feeding device of this embodiment, and 33 is a reference guide for guiding the reference side of the paper to be automatically fed.

The illustrated embodiment has three paper feed rollers so that the position of the reference guide 33 is kept constant and sheets of various sizes can be fed without changing the position of the paper feed roller.
The distance between the two rollers 1A and 1B on the side closer to the reference guide 33 is relatively narrow, so that even small paper such as postcards can be fed without causing the paper to skew. There is.

The holding roller 32 is attached to the side opposite to the reference guide of the roller 1C furthest from the reference guide 33, and its diameter is smaller than the diameter of the paper feed roller 1.
The length is set to cover the area where the bottom sides 21a to 21d of the paper-feedable envelopes 20a to 20d are located when the top sides 23 of the envelopes 20a to 20d are set against the reference guide 33. Auxiliary roller 31
is provided to prevent the envelope 20 from floating between the paper feed rollers 1B and 1C, and has the same diameter as the press roller 32. roller 1
A to 1C and 32 are made of a rubbery material with a rough surface and a high coefficient of friction. The presser roller 32 is fixed to the paper feed roller shaft 30, and therefore, when feeding paper, the paper feed rollers 1A to 1C
rotates at the same rotational speed. It goes without saying that friction pads 2 are pressed against the peripheral surfaces of the paper feed rollers 1A to 1C, respectively, as shown in FIG.

According to such a structure, as shown in FIG. 4, even if the top surface of the stacked envelopes 20 is slanted due to the overlapping portion 22 on the bottom side 21 side, the stacked envelopes 20 will be fed at the time of paper feeding. The pressing roller 32 suppresses lifting of the uppermost envelope 20 and the bottom portion, thereby preventing the envelope 20 from being bent greatly at the paper feed roller 1C portion as shown in FIG. Therefore, due to the principle explained in the above operation section, the feeding of the envelope 20 is not obstructed by the paper feed roller 1 portion, and the envelopes 20a to 20
d It is possible to completely prevent the occurrence of problems such as skew feeding and failure to feed paper.

-Effects of the Invention- As described above, according to the present invention, when an envelope is used as the paper in an automatic paper feeder structured to separate the paper by passing the paper between the friction pad and the paper feed roller, It is possible to completely prevent the occurrence of skewed paper feeding and failure of paper feeding with a simple structure, and therefore, it is possible to smoothly and reliably feed not only ordinary office notes but also envelopes of various sizes. Therefore, it is possible to provide an automatic paper feeder that is capable of printing paper, and to provide a more versatile printer that can be used with any type of printing paper.

[Brief explanation of the drawing]

Figures 1 and 2 are views showing essential parts of an embodiment of the present invention, with Figure 1 being a plan view showing the paper feed roller portion, and Figure 2 being a perspective view showing the state when envelopes are being fed. be. FIG. 3 is a side view schematically showing the structure of a main part of an automatic paper feeder according to the present invention, and FIG. 4 is a perspective view showing a state in which envelopes are fed in a conventional apparatus. In the figure, 1 (1A, 1B, 1C): paper feed roller,
2: Friction pad, 7: Paper table, 20 (20a, 2
0b, 20c, 20d): Envelope, 21 (21a,
21b, 21c, 21d): bottom of envelope, 30:
Paper feed roller shaft, 32: Press roller, 33: Reference guide.

Claims (1)

[Scope of Claims] 1. A plurality of paper feed rollers 1 that come into contact with the paper feed side edge of the top surface of the paper stacked on a paper table 1, and a friction pad 2 for paper separation that is pressed by the paper feed rollers. The friction pad contacts the paper feed roller 1 obliquely so as to deflect the paper slightly upward and send it out, and the paper fed out by the frictional force of the paper feed roller 1 is connected to the friction pad 2 In an automatic paper feeder that separates and feeds sheets by passing between the paper feed roller 1 and the paper feed roller 1, the paper feed roller 1 is coaxial with the paper feed roller 1 and has a diameter of the paper feed roller 1.
A pressing roller 32 is provided which has a smaller diameter and has a length that includes the passing position of the non-reference side side edges 21a to 22b of all the side edges 21a to 22b of all the horizontal supply envelopes used as paper in its surrounding area. An automatic paper feed device for a printer, characterized in that a presser roller 32 is rotated together with a paper feed roller 1.