JPS638677Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is an automatic feeder used in facsimile machines, copying machines, etc., which separates multiple originals stacked on a document table one by one and feeds them into the device. This relates to paper devices.

Configuration of conventional example and its problems As shown in FIG. A paper feed roller 4 is arranged, a rubber discrimination piece 5 is brought into contact with the paper feed roller 4, and one end of the support base 7 of the discrimination piece 5 rotatably provided on the shaft 6 is connected to the arrow line by a coil spring 8. By pulling the discrimination piece 5 in the direction of the paper feed roller 4,
It was under pressure.

In the conventional automatic paper feeder configured as described above, when the paper feed roller 4 rotates in the direction of the arrow 10, the originals 1 and 2 are fed, but the discrimination piece 5 detects the originals 2 other than the bottom layer paper 1. Since paper feeding was blocked, only the bottom layer paper 1 was being fed. That is, by simply rotating the paper feed roller 4, the plurality of originals 1 and 2 stacked on the original platen 3 are discriminated and fed one by one starting from the bottom layer.

The principle of this automatic paper feeder will be explained using FIG. 2. FIG. 2 is a diagram showing the operating principle of this automatic paper feeder, and the same members as in FIG. 1 are given the same reference numerals. In FIG. 2, F ₀ is the force with which the discrimination piece 5 presses the paper feed roller 4, and F ₁ is the force with which the rotating paper feed roller 4 is pressed.
Due to the frictional force generated between the roller 4 and the document 1,
The force that propels the original 1 in the paper feeding direction, F2 _, is the frictional force generated between the originals 1 and 2, which causes the original 1 to move towards the original 2.
The force that propels the paper in the feeding direction, and F ₃ is the force that propels the document 1,
The frictional force generated between the discriminating piece 2 and the discriminating piece 5 causes the discriminating piece 5 to prevent the originals 1 and 2 from being fed. When the pressing force F ₀ is adjusted and the force relationship satisfies the following equation, completely automatic paper feeding is performed in which originals are discriminated and fed one by one.

F ₁ > F ₃ > F ₂ ...1 Here, if the force F ₃ that prevents the feeding of originals 1 and 2 becomes larger than the force F ₁ that feeds original 1, the originals 1 and 2 will not be fed at all. On the other hand, original 1 becomes original 2.
The paper feed blocking force F ₃ is greater than the force F ₂ that propels the paper in the paper feeding direction.
When the number of originals becomes smaller, originals 1 and 2 are fed simultaneously without being discriminated, resulting in a so-called two-sheet feeding state. In other words, it is said that the automatic paper feeder with a larger difference between paper feed force F ₁ and paper feed blocking force F ₃ has a higher paper feeding ability, and the larger the difference between paper feed blocking force F ₃ and paper feed blocking force F ₂ , the higher the discrimination ability. was.

Note that the forces F ₁ to _{F 3} are generated by frictional forces, so the pressing force F ₀ , the friction coefficient of the surface of the paper feed roller 4 , the friction coefficient of the surface of the discrimination piece 5 , and the friction coefficient of the originals 1 and 2 It was proportional to the friction coefficient between the front and back surfaces.

Conventionally, according to this type of automatic paper feeder, if the leading edge of the originals 1 and 2 comes into contact with the discrimination piece 5 before being sandwiched between the paper feed roller 4 and the discrimination piece 5, the paper will not be fed at all. An inconvenience was occurring. Furthermore, if the friction coefficient of the surface of the discrimination piece 5 is increased with emphasis on improving the discrimination ability, the paper feed force F ₁ and the paper feed blocking force F ₃ will become close to each other, so even if only one document is discriminated and fed. Even if paper could be produced, there were disadvantages such as the manuscript being more likely to bend or wrinkle.

As a method to deal with these problems, as shown in FIG.
A thin piece 11 made of a low-friction material is provided only in the contacting part.
There is a way to set it up. This method eliminates the inconvenience of a document feeding failure occurring before the leading edge of the document is held between the paper feed roller 4 and the discrimination piece 5;
Because the leading edge of the original suddenly comes into contact with the high-friction part of the discrimination piece 5 from the low-friction part of the thin piece 11, the original may be bent or wrinkled at the leading edge of the original, or the low-friction member may be made too long, reducing the discrimination ability. I used to let them do things.

Purpose of the invention This invention solves the above-mentioned conventional problems.
It is an object of the present invention to provide an automatic paper feeding device that can increase paper feeding ability without reducing discrimination ability and can prevent the occurrence of bending and wrinkles in documents.

Structure of the invention The present invention has a discriminating piece made of a high-friction member in contact with a paper feeding means that rotates in the paper feeding direction, which is provided at the end of a document table on which a plurality of originals are stacked, and the paper feeding means of the discriminating piece A thin piece made of a low-friction material whose width becomes narrower in the paper feeding direction is provided on the contact surface with the paper, and the high-friction material is urged against the paper feeding means through this low-friction material, reducing the discrimination ability. It is possible to increase the paper feeding capacity without causing the document to bend or wrinkle.

DESCRIPTION OF THE EMBODIMENTS FIG. 4 is a schematic partial side sectional view of an automatic paper feeder according to an embodiment of the present invention, in which the same members as in FIG. 1 are given the same reference numerals. In Figure 4, 1
Reference numeral 2 denotes a thin piece made of a low-friction material such as plastic tape provided on the contact surface of the discrimination piece 5 with the paper feed roller 4. Reference numeral 13 indicates the paper feeding position where the paper feed roller 4, discrimination piece 5, and thin piece 12 begin to pinch the leading edges of the originals 1 and 2, and 14 indicates the paper feed position where the paper feed roller 4 and the discrimination piece 5 discriminate between the originals 1 and 2. It shows the discrimination position. Fifth
The figure is a schematic bottom view of the discrimination piece 5 according to an embodiment of the present invention, and as is clear from the figure, the width of the thin piece 12 becomes narrower in the paper feeding direction.

That is, in this embodiment, a thin piece made of a low friction material and whose width becomes narrow in the paper feeding direction is provided on the contact surface of the discrimination piece 5 made of a high friction material with the paper feeding roller 4, so that the paper feeding position can be adjusted. 13 has a large paper feeding capacity and a small discrimination capacity, and a discrimination position 14 has a small paper feeding capacity and a large discrimination capacity, and between the paper feeding position 13 and the discrimination position 14, This means that the paper feeding capacity is gradually reduced and the discrimination capacity is gradually increased.

Next, the operation will be explained using FIG. When the paper feed roller 4 rotates in the direction of the arrow 15, the documents 1 and 2 are
is fed in the paper feeding direction, and the leading edge of the original 1 or 2 comes into contact with the thin piece 12, but since the friction coefficient of the thin piece 12 is small, the original 1 or 2 is fed without being stopped.

At the paper feeding position 13, the paper feeding capacity is large and the discrimination capacity is small, so generally a plurality of documents 1 and 2 can be fed simultaneously.

Furthermore, between the paper feeding position 13 and the discrimination position 14, the paper feeding capacity gradually decreases and the discrimination capacity gradually increases. Since the capacity does not suddenly increase, the manuscript will not be bent or wrinkled.

Finally, at the discrimination position 14, since the thin piece 12 is not interposed between the paper feed roller 4 and the discrimination piece 5, the documents 1 and 2 can be reliably discriminated at this position.

As described above, in this embodiment, a thin piece made of a low-friction material whose width narrows in the paper feeding direction is attached to the contact surface side with the paper feeding means of the discrimination piece made of a high-friction material of a conventional automatic paper feeding device. By simply providing this, an automatic paper feeder with excellent paper feeding ability and discrimination ability can be obtained.

FIG. 6 is a perspective sectional view of a discrimination piece and a thin piece showing another embodiment of the present invention. In Figure 6,
16 is a discrimination piece made of a high friction material, and 17 is a thin piece made of a low friction material. As is clear from the figure, in this embodiment, the discrimination piece 16 is provided with a notch having the same shape as the thin piece 17, and the thin piece 17 is embedded in the notch, so that the discrimination piece 16 and the thin piece 17 are on the same plane. . It is clear that this embodiment also operates in the same manner as the previous embodiment. Further, in this embodiment and the previous embodiment, the discrimination piece and the thin piece may be integrally molded by a manufacturing method such as two-color molding.

Effects of the invention According to the invention, the discrimination piece 5 made of a high friction member
By providing a thin piece made of a low-friction material and whose width becomes narrower in the paper feeding direction on the contact surface with the paper feeding roller 4, the discrimination ability is reduced at the document feeding position.
Furthermore, since the frictional force gradually increases, it becomes easier to discriminate between originals, and the final discrimination ability remains the same, so it is possible to improve the paper feeding ability without reducing the discrimination ability. It has the effect of preventing bending and wrinkles.

[Brief explanation of drawings]

Figure 1 is a schematic side sectional view of a conventional automatic paper feeder.
Fig. 2 is a partially enlarged view showing the principle of a conventional automatic paper feeder, Fig. 3 is a schematic side sectional view of another conventional automatic paper feeder, and Fig. 4 is an automatic paper feeder in an embodiment of the present invention. FIG. 5 is a bottom view of the discrimination piece, and FIG. 6 is a perspective sectional view of the discrimination piece and the thin piece showing another embodiment of the present invention. 1, 2...Original, 3...Document stand, 4...Paper feed roller, 5...Discrimination piece, 7...Support stand, 12...Thin piece.

Claims (1)

[Scope of utility model registration request] A document table 3 on which a plurality of documents are stacked, a paper feed means 4 provided at the end of the document table 3 and rotating in the paper feeding direction, and a discrimination piece 5 made of a high friction member that contacts the paper feed means. , a thin piece 12 made of a low-friction material that is provided on the contact surface side of the discrimination piece 5 with the paper feeding means 4 and whose width becomes narrow in the paper feeding direction; An automatic paper feeder equipped with a biasing means 8.