JPH05105250A - Paper sheet feeder - Google Patents

Abstract

PURPOSE:To accomplish a paper sheet feeder used in the ADF of a copying machine or the like which can markedly reduce the number of parts, remarkably reduce the cost, reduce the weight, simplify the constitution of a feeder and simplify the configuration of a control system. CONSTITUTION:A paper sheet feed roller 11 is provided in such a manner as to freely rotate in the paper sheet feeding direction in a position in front of the leading edges of many paper sheets 60 stacked in a paper sheet feed tray. A paper sheet feed member 10 formed by folding a rubber elastic belt in two, with both end portions inserted in the paper sheet feed roller 11 to be connected thereto is fitted to the paper sheet feed roller 11. Following the rotation of the paper sheet feed roller 11 in the paper sheet feeding direction, the forward end side of the paper sheet feed member 10 is pressed to the leading edge portions of the paper sheets 60 and elastically deformed so that the forward end portion of the paper sheet feed member 10 is brought into close contact with the surface of the paper sheet 60 across a designated range. When the paper sheet feed roller 11 is further rotated from the close contact condition, the paper sheet 60, is fed downstream by the frictional force applied therebetween.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeder used for an ADF (automatic document feeder) equipped in, for example, a copying machine.

[0002]

2. Description of the Related Art As a sheet (original) feeding device used for an ADF, a friction delay type has been widely used. FIG. 3 shows a schematic structure of a feeding device adopting this system and its operation. The feeding device includes a paper feed roller 71 and a reverse rotation roller 72, which are vertically opposed to each other, and a paper feed roller 71.
The lever 73 that can be tilted around the rotation center of
And a draw-in roller 74 which is attached to the tip of the lever 73 and is pressed against the paper 60 in the paper feed tray from above.

The lever 73 is biased by a spring 75 in a direction in which the attracting roller 74 is separated from the paper 60 in the paper feed tray. When the lever 73 is forcibly tilted by the solenoid 76, the attracting roller 74 is moved. The uppermost sheet 60 in the sheet feed tray is pressed from above. The take-in roller 74 is rotated in the same direction as the rotation direction of the paper feed roller 71 by the revolving movement of the belt 77 wound around the shaft portion of this and the paper feed roller 71. On the other hand, the reverse rotation roller 72 is rotated in a direction opposite to the rotation direction of the paper feed roller 71 with a weaker rotational force.

In the paper feeding device having the above structure, the paper feeding operation of the paper 60 is performed as follows. First, FIG.
As shown in (A), the paper feed roller 71 and the reverse rotation roller 7
2 is rotated in the direction indicated by the arrow, and in this state, the solenoid 76 is turned on to tilt the lever 73 to press the attracting roller 74 against the uppermost sheet 60 (see FIG. 3B).

Then, the attracting roller 74 is rotated,
Due to this rotational force, the uppermost sheet 60 is fed from the sheet feed tray (see FIG. 3C).

The paper 60 fed from the paper feed tray is then conveyed between the paper feed rollers 71 and the reverse rotation roller 72, as shown in FIG. At this time, since the reverse rotation roller 72 is rotated in the opposite direction to the paper feed roller 71 with a weaker rotational force than this, the two or more sheets 60 are double-fed and the space between the paper feed roller 71 and the reverse rotation roller 72 is increased. When the paper is bitten by, the reverse rotation roller 72 pushes the lower paper 60 back toward the paper feed tray. As a result, the double feeding of the sheet 60 is eliminated.

When the paper 60 conveyed by the paper feed roller 71 toward the inside of the copying machine is caught at the leading end thereof by a timing roller 78 composed of vertically opposed rollers (FIG. 3).
(See (E)), and then the sheet is conveyed in synchronization with the copying operation by the rotational force of the timing roller 78. At this time, the paper feed roller 71 and the call-in roller 74 are stopped, and the solenoid 76 is turned off. Solenoid 76 is off
Then, the lever 73 is tilted toward the original position by the urging force of the spring 75, and the inviting roller 74 is returned to the standby position in preparation for the next sheet feeding operation.

[0008]

By the way, according to the sheet feeding device having the above-mentioned structure, at least two rollers, that is, the sheet feeding roller 71 and the inviting roller 74 are required, and further, the belt for rotating the inviting roller 74. 77, a member such as a lever 73, a spring 75, and a solenoid 76 is required as a mechanism for moving the attracting roller 74 toward and away from the sheet 60. Therefore, according to the above configuration, there are disadvantages that the number of parts is increased and the device configuration becomes large, heavy and complicated. Also, the paper feed roller 7
Turning on the solenoid 76 together with the rotation control of the rollers such as 1
Since the OFF control must be performed, there is also a drawback that the configuration of the control system becomes complicated. Further, there is a drawback that the cost is increased.

The present invention solves the above-mentioned drawbacks of the prior art, and can reduce the number of parts, reduce the cost, reduce the size and weight, simplify the device configuration, and further, the complicated control. An object of the present invention is to provide a sheet feeding device that does not require a system.

[0010]

SUMMARY OF THE INVENTION A sheet feeding device of the present invention is a sheet feeding device that feeds sheets one by one forward, and has a rotating body and elasticity. The base end side is connected to, and a feeding member that feeds the sheet at the tip end portion that is pressed against the sheet as the rotating body rotates is achieved, and thereby the above object is achieved.

Preferably, a rubber belt is bent to form the feeding member.

Further, preferably, a reverse rotating body for prohibiting the double feeding of the paper is provided in the rotation region of the rotating body.

Further, preferably, a protrusion is formed on the outer peripheral portion of the rotating body to prohibit the post-feeding of the sheet.

[0014]

In the above structure, when the rotating member is rotated, the leading end side of the feeding member is pressed against the leading end portion of the paper, and subsequently elastically deformed. As a result, the leading end of the feeding member comes into close contact with the surface of the leading end of the paper over a predetermined range. Therefore, when the rotating body is further rotated from this state, the paper is fed forward, that is, on the downstream side in the feeding direction by the frictional force acting between the two. When the rotator further rotates from this state, the leading end of the feeding member separates from the paper, and its elastic restoring force restores the original shape.

[0015]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 shows a sheet feeding apparatus according to the present invention, which is mounted on, for example, an ADF of a copying machine.
Sheets are fed one by one from among a plurality of sheets stacked in the sheet feed tray 20 and conveyed toward the inside of the copying machine. The specific configuration will be described below step by step.

A paper feed roller 11 is provided in front of the paper feed tray 20.
Is rotatably arranged in the paper feeding direction indicated by the arrow. On the outer periphery of the paper feed roller 11, the paper feed member 1 is formed in a tongue shape as a whole.
0s are concatenated. The paper feed member 10 rotates integrally with the paper feed roller 11, takes out the uppermost paper 60 from the papers 60 stacked in the paper feed tray 20, and is provided opposite the paper feed roller 11 and the paper feed roller 11. The paper is fed between the reverse rotation roller 30 and the reverse rotation roller 30. The reverse rotation roller 30 is rotated in a direction opposite to the rotation direction of the paper feed roller 11 with a weaker rotational force. Further, in front of and behind the reverse roller 30, a paper guide 40a,
40b is arranged.

The separation distance between the paper feed roller 11 and the reverse rotation roller 30 is set sufficiently smaller than the separation distance between the paper feed roller 11 and the paper feed tray 20.

The paper feed member 10 is constructed by inserting and connecting both ends of an elastic belt folded in two into slits formed on the outer peripheral surface of the paper feed roller 11. The tip end side of the sheet feeding member 10 bulges into a curved shape due to its elastic restoring force. The leading end of the paper feed member 10 contacts the paper 60 in the paper feed tray 20 with its connecting portion facing the paper feed tray 20 side. Further, the outer peripheral surface of the sheet feeding roller 11 and a portion located on the downstream side (downstream side in the rotation direction) of the sheet feeding member 10 is provided with a convex portion 12 having an arc shape over a range of approximately 90 °. Has been. The convex portion 12 is arranged so as to be close to the peripheral surface thereof while facing the reverse rotation roller 30.

The sheet feeding member 10 which is in contact with the sheet 60 in the sheet feeding tray 20 is elastically deformed as the sheet feeding roller 11 rotates in the sheet feeding direction, and the sheet 60 is gradually pushed while being strongly fed. The paper is fed between the roller 11 and the reverse rotation roller 30. The elastic belt forming the sheet feeding member 10 is made of a non-slip material such as hard rubber so that the sheet 60 can be reliably fed by a frictional force. Paper 6 fed from paper tray 20
0 is conveyed while being guided by the paper guide 40b.

A specific sheet feeding operation of the sheet 60 will be described below with reference to FIG.
Follow the instructions below. As shown in FIG. 2A, the paper feed member 10 maintains a tongue-like shape due to the elastic restoring force of the material when there is no load apart from the paper 60.
The length L of the sheet feeding member 10 when no load is applied is shown in FIG.
It is sufficiently longer than the length M under load, which allows the leading end portion of the paper feed member 10 to come into close contact with the surface of the paper 60 over a predetermined range under load to exert sufficient frictional force. ing.

From the state shown in FIG.
When the sheet is rotated, as shown in FIG.
The top of the paper 6 in the paper feed tray 20 from the top
Abut 0. When the paper feed roller 11 is further rotated from this state, as shown in FIG. 2C, the paper feed member 10 is elastically deformed, and its restoring force presses the leading end of the paper 60 strongly from above. Further, when the paper feed roller 11 is rotated, the elastic deformation of the paper feed member 10 further progresses, and the leading end portion thereof comes into close contact with the leading end portion of the paper 60 over a predetermined range. Therefore, in this state, the contact area between the two becomes large, so that a large frictional force is generated between them. This friction force causes the paper 6
0 is conveyed toward the front side as the paper feed roller 11 and the paper feed member 10 rotate.

When the paper feeding member 11 is further rotated, FIG.
As shown in (D), the paper 6 conveyed by frictional force
The leading edge of 0 is caught between the paper feed roller 11 and the reverse rotation roller 30. In this state, the elastic deformation of the sheet feeding member 10 further progresses, and the frictional force further increases.
It is possible to reliably convey the sheet 60 toward the front side against the rotational force of the reverse rotation roller 30. The reverse rotation roller 30 is arranged to prevent double feeding of the paper 60. That is, paper 6
When two sheets of 0 are fed, the rotational force of the reverse rotation roller 30 overcomes the frictional force generated between the upper and lower sheets 60, 60,
Since the lower sheet 60 is post-fed toward the sheet feed tray 20, the double feeding of the sheet 60 is eliminated.

When the sheet feeding member 11 is further rotated from the state shown in FIG. 2D to continue the conveyance of the sheet 60, the sheet shown in FIG.
As shown in (E), the leading edge of the sheet 60 is bitten by the timing roller 50 formed by vertically arranging the rollers. At this time, since the timing roller 50 is stopped, the sheet 60 is conveyed while being bent upward as shown by the broken line in the figure. As the rotation of the paper feed roller 11 progresses further, as shown in FIG.
As shown in (F), the sheet feeding member 10 separates from the sheet 60. When the paper feed member 10 separates, the paper 60 is unbent by the restoring force due to the strength of its waist, and is linearly conveyed toward the timing roller 50 side.

Thereafter, the convex portion 12 is pressed against the peripheral surface of the reverse rotation roller 30 with the rear end portion of the paper 60 being sandwiched therebetween. Therefore, after the paper feed member 10 separates from the paper 60, the convex portion 12 carries the paper 60. Providing such a convex portion 12 has an advantage that the backward feeding of the sheet 60 by the reverse rotation roller 30 can be reliably prevented.

When the leading edge of the sheet 60 is securely caught in the timing roller 50, the rotation of the sheet feeding roller 11 and the reverse rotation roller 30 is stopped. The rotation of the timing roller 50 is performed in synchronization with the copying operation.

As described above, in the paper feeding apparatus of the present invention, only the rotating operation of the paper feeding member 10 connected to the paper feeding roller 11 causes the papers 60 in the paper feeding tray 20 to be sequentially transferred from the topmost copying machine. Since the paper can be fed toward the inside, the number of parts can be remarkably reduced as compared with the conventional friction type feeding device. Therefore, the device configuration can be reduced in size, weight, and simplicity. Further, since the solenoid 76 is unnecessary, the control system can be simplified. For these reasons, the sheet feeding device of the present invention can significantly reduce costs.

In the above embodiment, the paper feed member 10 is made of an elastic belt, but the present invention is not limited to such an elastic belt, and at least the tip end surface is provided with a friction material such as a friction material, unevenness or a groove. It is also possible to use a so-called friction tape formed by bending a sheet material. Also,
It is also possible to use a solid elastic body or a bag-shaped elastic body containing gas.

Further, in the above embodiment, the convex portion 12 is used as a means for preventing the post-feeding of the sheet, but a roller having a half-moon shaped cross section may be used instead of the convex portion 12.

Further, in the above embodiment, the case where the sheet feeding device of the present invention is applied to the ADF of the copying machine has been described, but the same can be applied to other feeding devices such as the multi-feeding mechanism of the copying machine. ..

[0031]

According to the sheet feeding apparatus of the present invention described above,
The paper can be fed simply by attaching the feeding member to the rotating body. Therefore, the number of parts of the feeding device can be remarkably reduced as compared with the above-described conventional feeding device, and there are advantages that cost reduction, size reduction, weight reduction, and device configuration simplification can be achieved. Furthermore, since a complicated control system is not required, there is an advantage in this point that the cost can be greatly reduced and the device configuration can be simplified.

Particularly, according to the sheet feeding device of the third aspect, there is an advantage that the sheet can be surely fed one by one from among the stacked sheets.

Further, in particular, according to the sheet feeding device of the fourth aspect, there is an advantage that the sheet can be fed more reliably.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment in which a sheet feeding device of the present invention is applied to an ADF of a copying machine.

FIG. 2 is a view showing a feeding operation of the sheet feeding device of the present invention.

FIG. 3 is a view showing a feeding operation of a conventional sheet feeding device.

[Explanation of symbols]

 10 Feeding Member 11 Paper Feeding Roller 12 Convex 20 Paper Feeding Tray 30 Reverse Roller 60 Paper

Claims (4)

[Claims] 1. A sheet feeding device for feeding sheets one by one forward, comprising: a rotating body and elasticity; a base end side is connected to the rotating body; A sheet feeding device including a feeding member that feeds the sheet at a front end pressed against the sheet. 2. The sheet feeding device according to claim 1, wherein the feeding member is formed by bending a rubber belt. 3. The sheet feeding apparatus according to claim 1, further comprising a reverse rotating body that prohibits the double feeding of the sheet in the rotation range of the rotating body. 4. The sheet feeding device according to claim 3, wherein a protrusion for prohibiting post-feeding of the sheet is formed on an outer peripheral portion of the rotating body.