JPH0351231A - Paper feeding device of image forming equipment - Google Patents

Abstract

PURPOSE:To make it hard for the folds of paper feeding rollers to be torn by projecting the folds with slant toward the rotational direction of the paper feeding roller, and making the folds not to be reversed in the direction reverse to the slant direction when the paper feeding roller is driven in the rotational direction. CONSTITUTION:Folds 5 are projected with slant toward the rotational direction of a paper feeding direction. So, the folds 5 are not reversed in the direction reverse to the slant direction when the paper feeding roller 2 is applied by the force of the rotational direction to be driven by means of a pair of carrying rollers 4 via papers 11. Consequently, the paper feeding rollers 2 are driven, the folds are moved along the moving direction of the papers 11 so that the folds 5 are hard to be torn off.

Description

[Detailed Description of the Invention] The present invention relates to a paper feeding device for an image forming apparatus.
In particular, the present invention relates to a paper feeding device such as a stack bypass used in an image forming apparatus such as an electrophotographic copying machine.

A paper feeding device such as a distorted stack bypass uses a plurality of rollers such as a paper feeding roller. FIG. 6 is a diagram schematically showing a cross section of a conventional paper feeding device.

Paper (11) is loaded on the pressure plate (6), and a force is applied to the pressure plate (6) in the direction of arrow (a) so that the paper (11) is pressure-bonded to the advance roller (1). has been added. As the advance roller (1) rotates in the direction of arrow (b), the paper (11) on the pressure bonding plate (6) is pressed against the separation roller (3) in order from the top to the paper feed roller (2).
sent to. At this time, the paper feed roller (2) is moved by the arrow (
C) It is driven to rotate in the direction.

On the other hand, in order to prevent double feeding when two or more sheets of paper (11) overlap and are sent to the paper feed roller (2), the separation roller (3) is driven to rotate in the direction of arrow (d). are doing. This separation roller (3) has a one-way torque limiter, so if only one sheet of paper (11) is sent to the paper feed roller (2), the paper is fed through this one sheet of paper. The frictional force generated between the separation roller (3) and the roller (2) is large, so that the separation roller (3) is moved in the direction opposite to the arrow (d) (in the direction of the arrow (e)) by the paper (11) conveyed by the paper feed roller (2). ). When two or more sheets of paper (11) are fed into the feed roller (2), the frictional force becomes smaller, so the separation roller (3) rotates in the direction of arrow (d) and removes the topmost paper. The advance of the lower paper is prevented so that only the paper is fed out. The paper (11) sent out from the paper feed roller (2) passes between the upper guide plate (9) and the lower guide plate (10), and then passes through a pair of transport rollers that rotate in the directions of the arrows. (4) in the direction of arrow (5).

As shown in the same article, the paper feed roller (2), advance roller (1), and separation roller (3) are It is made of a rubber material with folds (5) that are inclined in one direction. The folds (5) are formed by, for example, polishing the circumferential surface of a roller made of a soft rubber material with low hardness. It is formed to protrude obliquely in the opposite direction. Therefore, the driven paper feed roller (2) and advance roller (1) as well as the driven or driven separation roller (3) are
Rotates in the same direction as the direction of rotation.

By the way, the paper (11) is normally transported by the pair of conveying rollers (4).
The transport speed of paper (11) by paper feed roller (2) is
) is faster than the transport speed. In particular, the paper feeding device of a high-speed machine transports the paper (11) at low speed with the paper feed roller (2) to prevent double feeding until the paper (11) is fed into the transport roller pair (4). ) is the double feed roller pair (
4), the paper (11) is transported at high speed by a pair of transport rollers (4).

However, the normal paper (11) is
Even when the paper is fed into the paper, it is held between the paper feed roller (2) and the separation roller (3) on the upstream side.

As a result, a difference occurs in the conveyance speed of the paper (11) between the conveyance roller pair (4) and the paper feed roller (2). In order to eliminate problems such as the paper (11) slipping due to this difference in conveyance speed and a jam being determined to have occurred, a one-way clutch is built into the paper feed roller (2). Therefore, the paper feed roller (2) is driven in the direction of the arrow (C) by the paper (11) transported by the transport roller pair (4).

Fig. 4(A) shows the state of folds <5) when the paper feed roller (2) of the conventional example is driven, and Fig. 4(B) shows the state of the fold <5) when the paper feed roller (2) of the conventional example is driven. It shows the state of the folds (5) when As shown in the figure, when the paper feed roller (2) is driven, the roller (2) rotates in the direction of arrow (C), so the folds (5) are aligned in the direction of rotation, and the paper (
11) is conveyed in the direction of arrow (i).

On the other hand, when the paper feed roller (2) is driven, the direction of rotation of the roller (2) (arrow (C)), the direction of inclination of the folds (5), and the direction of movement of the paper (11) (arrow (i)) are Even when the paper is driven, the paper (11) rotates the paper feed roller (2), so the folds (5) are reversed in the direction opposite to the direction of inclination thereof.

With the size of paper used in a single-pan normal paper feeder, the time the paper feed roller is driven by receiving the transport force from the transport roller through the paper is longer than the time the paper feed roller is driven. Therefore, the time for the folds to turn in the opposite direction to the inclination direction increases, making the folds more likely to tear.Especially, as the size of the paper increases, the folds become longer. Tears easily occur.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a paper feeding device in which tearing of the folds of the paper feeding roller is less likely to occur.

Means for Solving the Problems In order to achieve the above object, in the paper feeding device of the present invention, after the paper on the pressure bonding plate is fed by the advance roller to the paper feeding roller which is in pressure contact with the separation means, the paper feeding roller In a paper feeding device of an image forming apparatus, the paper feeding device is configured to feed sheets one by one to a pair of conveying rollers, and is made of a rubber material having folds on the circumferential surface of the paper feeding roller that are inclined in one direction. , the folds are configured to project obliquely toward the rotational direction of the paper feed roller.

-■ According to the configuration of the present invention, since the pleats project obliquely in the direction of rotation of the paper feed roller, for example, the paper feed roller is driven by a force in the rotation direction by the conveyance roller pair through the paper. The folds do not flip in the direction opposite to the direction of inclination when the folds are tilted. Therefore, when the paper feed roller is driven, the folds are along the moving direction of the paper, and tearing of the folds is less likely to occur.

EMBODIMENT OF THE INVENTION Hereinafter, embodiments of the present invention will be described based on the drawings. Incidentally, the same parts as those in the conventional example shown in FIG. 6 are given the same reference numerals, and the description thereof will be omitted.

FIG. 1 schematically shows the state in which the paper (11) stacked on the pressure bonding plate (6) is pressed against the advance roller (1) in this embodiment. Paper feed roller (2) of this embodiment
), the forward feed roller (1), and the separation roller (3) are all made of a soft rubber material on their peripheral surfaces, but are not limited to this, and other rubber materials may be used as appropriate. Further, in this embodiment, a separation roller (3) is used as the separation means, but a friction band or the like may also be used. There are rollers (1) on the circumferential surfaces of the paper feed roller (2) and the advance roller (1), respectively.
The folds (5) project obliquely toward the direction of rotation of (2).
) is formed. Therefore, the paper feed roller (2
) and the advance roller (1) rotate in opposite directions with respect to the rotation direction. Also, on the circumferential surface of the separation roller (3), there is an arrow (
d) Folds (5) are formed so as to project obliquely in the opposite direction. Therefore, the driven or driven separation roller (
3) rotates in the same direction as the rotation direction.

When conveying the paper (11) on the pressure bonding plate (6) to the paper feed roller (2), first, a force in the direction of arrow (j) is applied to the lower part of the pressure bonding plate (6) by the pressure bonding plate driving means (7). Added.

The crimp plate (6) is centered on the shaft (8) in the direction of arrows (j) (g).
It is configured to be rotatable in the direction of the arrow U), and is biased in the direction of the arrow (a) when a force is applied in the direction of the arrow U). As the pressure bonding plate driving means (7), means such as eccentric cams and solenoids, which are normally used in paper feeders, can be used in appropriate combination with control means such as a microcomputer.

FIG. 2 shows the state when the pressure bonding plate (6) is released in this embodiment. The paper (11) on the pressure bonding plate (6) that is in pressure contact with the advance roller (1) is moved to the paper feed roller (2).
), and at the same time, a force in the direction of arrow (G) is applied to the lower part of the pressure bonding plate (6) by the pressure bonding plate driving means (7). As a result, the crimp plate (6) is released as shown in FIG. The timing for releasing the pressure bonding plate (6) is set in advance by counting with a control device such as a microcomputer.

In a normal paper feeding device, after the paper (11) has been fed to the paper feeding roller (2) to some extent, the pressure bonding plate (6) is released. However, for reasons described later, it is preferable to release the pressure plate (6) immediately after the paper (11) is fed into the paper feed roller (2).

In particular, as in this embodiment, the paper (11) is
), it is preferable that the pressure plate (6) is released at the same time. The timing for releasing pressure=7FFi(6) will be explained below. FIG. 5 is a schematic diagram showing a state in which the paper (11) is held between the paper feed roller (2) and the separation roller (3). The paper feed roller (2) is driven in the direction of arrow (C), and the separation roller (3) is driven in the direction of arrow (e). The upstream side of the paper (11) is as described above (
If it is biased by the pressure bonding plate (6) and located at a position higher than the press surface between the paper feed roller (2) and the separation roller (3), the leading edge of the paper (11) will be undulated as shown in the figure. Sign.

The paper (11) is moved to the transport roller pair (4) in a wavy state.
), waving is regulated and conveyance noise and crunching noises are likely to occur as well as conveyance failures. Therefore, the paper (
11), forward feed roller (1) and pressure bonding plate (6)
If the state in which the paper (11) is simultaneously held and held by the paper (11) is made as short as possible, it is possible to suppress the occurrence of waviness of the paper (11). As a result, conveyance noise and poor conveyance do not occur.

As shown in FIG. 2, when the pressure bonding plate (6) is released, one sheet of paper (11) has been fed into the paper feed roller (2), so the separation roller (3) rotates in the direction of arrow (e). At this time, the paper feed roller (2) is turned against the direction of rotation, and the paper (
The separation roller (3) that is driven by the conveyance of the paper 11) also has a reverse mesh. Figure 3 (^) shows the paper feed roller (
2) shows the state of the folds (5) when it is being driven. As shown in the figure, the paper feed roller (2) rotates in the direction of arrow (C) to convey the paper (1l) in the direction of arrow (i), so that the folds (5) in contact with the paper (11) are reversed.

However, since the driving time of the paper feed roller (2) is short, tearing of the folds (5) is unlikely to occur.

Similar to the conventional example shown in Fig. 6, in this embodiment shown in Fig. 2,
The leading edge of the paper (11) is connected to the upper guide plate (9) and the lower guide plate (
10) and is fed to the pair of conveying rollers (4), the sheet (11) is conveyed faster than the conveying speed by the paper feed roller (2). As a result, the paper feed roller (2
) and separation roller (3) are both driven by a pair of transport rollers (4) via the paper (11). Figure 3 (B
) shows the state of the folds (5) when the paper feed roller (2) of this embodiment is driven.

As shown in the figure, the paper (11) moves in the direction of arrow (i) and rotates the paper feed roller (2), so the slope of the folds (5) follows the direction of movement of the paper (11). Therefore, the larger the size of the paper (11) being conveyed, the more the roller (
2) Although the following time in (3) is longer, tearing of the folds (5) is less likely to occur because the slope of the folds (5) follows the moving direction (arrow (i)) of the paper (11). In addition, separation roller (3)
The same applies to

In addition, as mentioned above, the pressure bonding plate (6) is connected to the paper feed roller (2).
Since the advance roller (1) is released at the same time as the paper (11) is sent in, the advance roller (1) is not driven by the transport roller pair (4) via the paper (11). Therefore, regarding the forward feed roller (1), the pleats (5) thereof may be in the normal direction or in the reverse direction with respect to the direction of rotation (direction of arrow (b)). However, after releasing the pressure bonding plate (6), the forward feed roller (1
) may be rubbed downstream by the paper (11) for a long time. Therefore, the forward feed roller (1) also has pleats (like the present embodiment) so as to be opposite to the direction of rotation.
5) is preferably formed.

Light Plate ■Four Past As explained above, in the paper feeding device of the present invention, the folds project obliquely toward the rotation direction of the paper feed roller, so when the paper feed roller is driven in the rotation direction, the folds does not reverse in the direction opposite to the direction of inclination. Therefore,
According to the present invention, it is possible to realize a paper feeding device in which tearing of the folds of the paper feeding roller is less likely to occur.

[Brief explanation of drawings]

FIG. 1 is a view showing an embodiment when the sheet on the pressure bonding plate is pressed against the advance roller, and FIG. 2 is a view showing the embodiment when the pressure bonding plate is released. FIG. 3 is a diagram showing the state of the folds when the paper feed roller used in the embodiment is driven or driven. FIG. 4 is a diagram showing the state of the folds when the paper feed roller used in the conventional example is driven or driven. FIG. 5 is a diagram showing a state in which paper is held between a paper feed roller and a separation roller. FIG. 6 is a diagram for explaining the operation of the conventional example. (1--Advance roller, (2)-Paper feed roller. (3-Separation roller, (4)--Conveyance roller. (5--Fold, (6)--Crimping plate. (7) - Crimping plate driving means, (8) - shaft. (9 - upper guide plate, (10) - lower guide plate (11)
-Paper.

Claims (1)

[Claims] (1) After the paper on the pressure bonding plate is fed by the advance roller to the paper feed roller that is in pressure contact with the separating means, the paper is fed one by one to the pair of transport rollers by the paper feed roller, In the paper feeding device of the image forming apparatus, the peripheral surface of the paper feeding roller is formed of a rubber material having folds inclined in one direction, and the folds protrude obliquely toward the rotational direction of the paper feeding roller. A paper feeding device characterized by the following.