JPH1029735A - Automatic paper feeding mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic paper feeding mechanism capable of preventing paper sheets from being fed overlapped and in a bad manner and of improving the performance to feed paper sheets separated by automatically adjusting the separation pressure of the paper sheet even if the tip position of the bundle of paper sheets to be inserted between a paper feeding roller and a separation pad. SOLUTION: A pressure contact member 11 is provided, which is capable of swing around a shaft 12 whose axial line is parallel with the rotary axis of a paper feeding roller 5, and the shaft 12 is provided between the tip section of the pressure contact member 11 for pressure contact a separation pad 6 against the paper feeding roller 5 and a given position in the pressure contact member 11, in which the tip section of a document contacts between the separation pad 6 and the paper feeding roller 5. In such constitution, the separation pressure of the document due to the separation pad can be varied by swinging the pressure contact member 11 around the shaft 12 according to the position of the tip section of the document bundle P contacting between the separation pad 6 and the paper feeding roller 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic paper feed mechanism provided in an image processing apparatus such as a copying machine, a facsimile machine, a scanner, a printer, and the like. The present invention relates to an automatic sheet feeding mechanism that separates sheets one by one from a sheet bundle by a separation pad.

[0002]

2. Description of the Related Art Conventionally, in an image processing apparatus such as a copying machine, a facsimile apparatus, a scanner apparatus, and a printer apparatus, an automatic feeding is performed to separate and feed a plurality of sheets placed on a sheet placing table. A paper mechanism is provided, and the automatic paper feed mechanism includes a paper feed roller and a separation pad extending in the paper feed direction and pressed against the outer peripheral surface of the paper feed roller.

In an automatic paper feed mechanism having such a configuration, a sheet bundle is inserted between a paper feed roller and a separation pad, and the paper feed roller is rotated in a paper feeding direction to thereby separate the separation pad. The sheet on the side pressed against the sheet is prevented from being separated, and the sheets are separated one by one from the sheet bundle.

[0004]

However, in such a conventional automatic sheet feeding mechanism, the position of the leading end of the sheet bundle inserted between the sheet feeding roller and the separation pad when the sheet bundle is set is determined. There has been a problem that the separation pad is pushed up by the sheet bundle and the separation pressure of the sheets fluctuates, so that the sheets are multi-fed or defective feeding occurs.

Accordingly, the present invention provides a method for automatically adjusting the separation pressure of a sheet even when the leading end position of a sheet bundle inserted between a sheet feeding roller and a separation pad varies, and It is an object of the present invention to provide an automatic paper feed mechanism that can prevent double feed and poor feed and can improve paper separation / feed performance.

[0006]

According to the first aspect of the present invention,
In order to solve the above-mentioned problem, a paper feed roller and a separation pad extending in a paper feed direction and having a leading end pressed against an outer peripheral surface of the paper feed roller are provided. A press contact member that presses the separation pad against a sheet feed roller in an automatic sheet feeding mechanism that separates sheets one by one from the sheet bundle by rotating a sheet feed roller after inserting a sheet bundle between the sheet feed rollers. Is attached to the separation pad, and the pressure contact member is
A press-contact force applying member is provided so as to be swingable about a rotation fulcrum having an axis parallel to the rotation center axis of the paper feed roller, and presses the tip of the rotation fulcrum to the separation pad with a predetermined pressure. The rotation fulcrum is provided between a tip of a pressure contact member that presses the separation pad against the paper feed roller and a predetermined position of the pressure contact member where the tip of the sheet bundle contacts between the separation pad and the paper feed roller, The separation pressure of the sheet bundle by the separation pad is varied by swinging the pressing member about the rotation fulcrum according to the leading end position of the sheet bundle that comes into contact between the separation pad and the paper feed roller.

In this case, when the leading end of the sheet bundle is inserted between the paper feed roller and the separation pad, the pressing member swings about the rotation fulcrum by the insertion pressure of the sheet bundle, and the leading end of the pressing member is separated. Is pressed against the sheet feed roller.
At this time, when the leading end portion of the sheet bundle is inserted slightly between the separation pad and the paper feed roller (downstream in the sheet transport direction), the force of the sheet bundle pressing the pressing member increases, and the pressing member is pressed. Swings about the rotation fulcrum, and the leading end thereof presses the separation pad against the paper feed roller, and the pressure of the separation pad presses the sheet bundle with the rotation of the paper feed roller increases. As a result, double feeding of paper does not occur.

Further, when the leading end of the sheet bundle is slightly inserted between the separation pad and the sheet feed roller (upstream in the sheet conveying direction), the force of the sheet bundle pressing the pressure contact member is reduced. The pressure contact member swings about the rotation fulcrum, and the leading end of the pressure contact member presses the separation pad against the sheet feeding roller, and the pressure contact force with which the separation pad presses the sheet bundle with the rotation of the sheet feeding roller decreases. It does not become weak and does not cause paper feeding failure.

As described above, the pressing force of the pressing member can be adjusted according to the insertion position of the leading end of the sheet bundle, thereby preventing the occurrence of double feeding and defective feeding of the sheets and improving the sheet separating and feeding performance. Can be done. According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, a shaft constituting the rotation fulcrum and a pressure contact member support plate having an elongated hole through which the shaft is inserted are provided. Wherein the elongated hole extends a predetermined length in the same direction as the outer peripheral surface of the sheet feeding roller.

In this case, in addition to the effect of the first aspect of the present invention, the difference between the frictional force between the paper and the separation pad and the frictional force between the separation pad and the paper supply roller due to the rotation of the paper supply roller. The press-contact member reciprocates along the outer peripheral surface of the sheet feeding roller together with the separation pad, and sheets other than the sheet separated from the sheet bundle can be pulled back by the separation pad. As a result, the occurrence of double feeding of sheets can be more reliably prevented, and the sheet separating and feeding performance can be further improved.

According to a third aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, a driving means for driving a paper feed roller to rotate in reverse when the feeding of the final paper is completed, A pressure contact member support plate having a long hole extending a predetermined length from a predetermined position on the outer peripheral surface of the paper feed roller to a position separated from the paper supply roller, through which a shaft constituting a rotation fulcrum is inserted; When the paper feeding is completed, the shaft is moved in the direction away from the paper feeding roller along the long hole by driving the paper feeding roller in reverse direction to widen the gap between the paper feeding roller and the separation pad. And

In this case, in addition to the operation of the first aspect, when the feeding of the final sheet is completed, the distance between the sheet feeding roller and the separation pad may be increased by driving the sheet feeding roller to rotate in the reverse direction. As a result, a large number of thick bundles of paper can be easily inserted between the paper feed roller and the separation pad to reliably contact the paper feed roller, and the occurrence of double feeding of paper is more reliably prevented. As a result, the paper separating and feeding performance can be further improved.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, a driving means for driving a sheet feeding roller to rotate in reverse when the feeding of the last sheet is completed, A shaft constituting a rotation fulcrum, and a pressure-contact member support plate having a long hole through which the shaft is inserted,
The elongated hole extends in the same direction as the outer peripheral surface of the sheet feeding roller from the leading end in the sheet conveying direction to the trailing end by a predetermined length, and extends by a predetermined length from the trailing end to a position separated outward from the sheet feeding roller. When the feeding of the final sheet is completed, the shaft is moved in a direction away from the sheet feeding roller along the elongated hole by driving the sheet feeding roller in the reverse direction when the feeding of the final sheet is completed. It is characterized in that the interval between the separation pads is widened.

In this case, in addition to the effect of the first aspect of the invention, the difference between the frictional force between the paper and the separation pad and the frictional force between the separation pad and the paper supply roller accompanying the rotation of the paper supply roller. The press-contact member reciprocates along the outer peripheral surface of the sheet feeding roller together with the separation pad, and sheets other than the sheet separated from the sheet bundle can be pulled back by the separation pad. In addition, when the last sheet is fed, the distance between the sheet feed roller and the separation pad can be increased by driving the sheet feed roller to rotate in the reverse direction. The paper feed roller can be easily inserted between the paper feed roller and the separation pad to reliably contact the paper feed roller, preventing the double feed of paper more reliably and further improving the paper separation / feeding performance. Can be.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of an automatic sheet feeding mechanism according to the present invention, and correspond to the first aspect of the present invention. The automatic paper feeding mechanism of the present invention can be applied to an image processing apparatus such as a copying machine, a facsimile machine, a scanner, and a printer.

First, the configuration will be described. In FIGS. 1 to 3, reference numeral 1 denotes a paper feeding unit of a copying machine as an image processing apparatus. The paper feeding unit 1 has a cover 3 that can be opened and closed with respect to a main body 2 of the copying machine. When the cover 3 is opened as shown by a broken line, the conveyance path of the original (paper) is exposed to the outside, so that the jammed original can be removed from the conveyance path.

On the main body 2 side of the copying machine, there is provided a document table 4 on which a document bundle (sheet bundle) P composed of a plurality of documents can be placed. A paper feed roller 5 and a separation pad 6 extending in the document feed direction and having a leading end pressed against the outer peripheral surface of the paper feed roller 5 are provided downstream of the document table 4 in the document transport direction. After the document bundle P is inserted between the paper feed roller 5 and the separation pad 6, the document is separated from the document bundle P one by one by rotating the paper feed roller 5.

The separated document is nipped by a pair of transport rollers 7 provided downstream of the paper feed roller 5 in the document transport direction and transported along a transport path 10. The contact image sensor (hereinafter, simply referred to as CIS) 9 is pressed against a contact glass 9a. The CIS 9 includes a known exposure lamp, a reflection mirror,
It comprises a lens, an image sensor, and the like, and reads an image of a document as is well known. Further, the white roller 8 prevents the document from being pressed against the contact glass 9a to be lifted from the contact glass 9a, and constitutes a white reference when reading the document.

On the other hand, a pressure contact member 11 is attached to the separation pad 6, and the pressure contact member 11 is a shaft forming a rotation fulcrum having an axis parallel to the rotation center axis of the paper feed roller 5.
The shaft 12 is swingably provided, and the shaft 12 is fixed to the cover 3. The distal end of the pressure contact member 11 contacts the separation pad 6 with the paper feed roller 5, and one end of a tension spring (pressing force applying means) 13 is attached to the base end. The other end of the tension spring 13 is attached to the cover 3, and the pressure contact member 11 receives the tensile force of the tension spring 13 so that the distal end of the pressure contact member 11 is centered on the shaft 12 at a predetermined pressure (initial pressure). To be pressed against.

The shaft 12 has a front end portion of a press contact member 11 for pressing the separation pad 6 against the paper feed roller 5 and a front end portion of the document 11 between the separation pad 6 and the paper feed roller 5 for contact of the front end of the document.
Are provided between predetermined locations. Next, the operation will be described. When the document bundle P is placed on the document placing table 4 and the start switch is pressed, the paper feed roller 5 rotates and the document bundle P comes into contact with the separation pad 6, and the pressing force of F 1 is applied to the separation pad 6.

At this time, the separation pad 6 generates a separation pressure F3 corresponding to the resultant force of the pressing force F1 and the tensile force S2 of the tension spring 13 using the shaft 12 as a fulcrum, and feeds the separation pad 6 with the separation pressure F3. It comes into pressure contact with the roller 5. Then, the lowermost original is separated from the original bundle P by the paper feed roller 5 rotating in the direction of the arrow, and is fed toward the transport roller pair 7.

At the time of this separation, when the leading end portion of the original bundle P is inserted into the space between the separation pad 6 and the paper feed roller 5 (downstream in the original transport direction), the original bundle P is pressed against the pressing member 11.
The pressing force F1 increases, and the pressing member 11
2, the leading end thereof presses the separation pad 6 against the paper feed roller 5, and the pressing force F3 becomes stronger.
With the rotation of, the pressing force of the separation pad 6 pressing the document bundle P is increased, so that double feeding of documents does not occur.

The leading end of the document bundle P is slightly closer to the front between the separation pad 6 and the paper feed roller 5 (upstream in the document transport direction).
When the document is inserted into the paper feeder, the force F1 of pressing the pressing member 11 by the original bundle P becomes small, and the pressing member 11 swings around the shaft 12 so that the leading end presses the separation pad 6 against the paper feed roller 5. As a result, the pressing force of the separation pad 6 pressing the bundle of documents P with the rotation of the paper feed roller 5 is weakened, and there is no occurrence of a defective document feeding.

As described above, in the present embodiment, the paper feed roller 5
A pressure contact member 11 swingable around a shaft 12 having an axis parallel to the rotation center axis of the
11 is provided with a tension spring 13 for pressing the tip of the shaft 12 to the separation pad 6 at a predetermined pressure F1 around the center of the shaft 12, and the shaft 12 is connected to the tip of the pressure contact member 11 for pressing the separation pad 6 to the paper feed roller 5. Section and separation pad 6 and paper feed roller 5
The pressing member 11 is provided between predetermined positions of the pressing member 11 where the leading end of the document comes in contact with the separation pad 6 and the paper feed roller 5, and the pressing member 11 is connected to the shaft 12 in accordance with the leading end position of the document bundle P that contacts between the separation pad 6 and the paper feed roller 5. By swinging to the center, the separation pressure of the document by the separation pad 6 is changed, so that the pressing force of the pressing member 11 can be adjusted by the insertion position of the leading end of the document bundle P,
It is possible to prevent double feeding and poor feeding of originals from occurring, thereby improving the separation and feeding performance of originals.

FIG. 4 is a view showing a second embodiment of the automatic sheet feeding mechanism according to the present invention, and corresponds to the second aspect of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 4, the cover 3 constitutes a press-contact member support plate,
Is provided with a long hole 15 through which a shaft is inserted, and the long hole 15 extends a predetermined length in the same direction as the outer peripheral surface of the sheet feeding roller 5.

In this embodiment, since the relative positions of the paper feed roller 5 and the separation pad 6 do not change, the basic operation is the first operation.
This is the same as the first embodiment, but since the elongated hole 15 extends a predetermined length in the same direction as the outer peripheral surface of the feed roller 5, in addition to the same effects as the first embodiment, Accordingly, due to the difference between the frictional force between the document bundle and the separation pad 6 and the frictional force between the separation pad 6 and the paper feed roller 5, the pressing member 11 together with the separation pad 6 is drawn along the outer peripheral surface of the paper feed roller 5 by a solid line. The reciprocating motion between the position indicated by the broken line and the position indicated by the broken line, and an effect that the document other than the document separated from the document bundle P can be pulled back by the separation pad 5 can be obtained.

FIG. 5 is a view showing a third embodiment of the automatic paper feed mechanism according to the present invention, and corresponds to the third aspect of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, a paper feed motor (not shown) that can rotate the paper feed roller 5 forward and reverse, and a document set sensor (not shown) that detects the presence or absence of a document placed on the document table 4, When the document set sensor detects that there is no document on the document table 4, it is determined that the last document has been fed based on the detection information from this sensor, and the feed motor is driven in reverse. (Not shown). In this embodiment, the sheet feeding motor,
The document set sensor and the controller constitute a driving unit.

A long hole 16 through which the shaft 12 is inserted is formed in the cover (pressing member supporting plate) 3, and the long hole 16 is formed at a predetermined position on the outer peripheral surface of the sheet feeding roller 5. A predetermined length is provided at a position separated from the camera.
In this embodiment, since the relative positions of the paper feed roller 5 and the separation pad 6 do not change, the basic operation is the same as that of the first embodiment. When the shaft 5 is rotated in the reverse direction, the shaft 12 moves in the direction away from the paper feed roller 5 along the elongated hole 16 so as to widen the space between the paper feed roller 5 and the separation pad 6 (the document bundle). (Since the tip insertion position is changed from A to the position shown in B), in addition to the same effects as in the first embodiment,
A large number of thick bundled originals can be easily inserted between the paper feed roller 5 and the separation pad 6 to reliably contact the paper feed roller 5, and the occurrence of double feeding of the originals can be more reliably prevented. As a result, the performance of separating and feeding the original can be further improved.

FIG. 6 is a view showing a fourth embodiment of the automatic sheet feeding mechanism according to the present invention, and corresponds to the invention described in claim 4. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, a paper feed motor (not shown) that can rotate the paper feed roller 5 forward and reverse, and a document set sensor (not shown) that detects the presence or absence of a document placed on the document table 4, When the document set sensor detects that there is no document on the document table 4, it is determined that the last document has been fed based on the detection information from this sensor, and the feed motor is driven in reverse. (Not shown). In this embodiment, the sheet feeding motor,
The document set sensor and the controller constitute a driving unit.

A long hole 17 through which the shaft 12 is inserted is formed in the cover (pressing member supporting plate) 3, and the long hole 17 is in the same direction as the outer peripheral surface of the paper feed roller 5 in the document conveying direction. It is formed to extend a predetermined length from the front end to the rear end, and to be bent so as to extend a predetermined length from the rear end to a position separated outward from the paper feed roller 5, so that the feeding of the final document is completed. At this time, the shaft 12 is moved in the direction away from the paper feed roller 5 along the elongated hole 17 by the reverse rotation of the paper feed roller 5 as shown by the solid arrow, and the paper feed roller 5 and the separation pad 6 are moved. The interval of the is expanded.

In this embodiment having such a configuration,
Since the relative positions of the paper feed roller 5 and the separation pad 6 do not change, the basic operation is the same as in the first embodiment. In addition, the document and the separation pad 6 are rotated with the rotation of the paper feed roller 5.
The pressure contact member 11 reciprocates along the outer peripheral surface of the paper feed roller 5 together with the separation pad 6 due to the difference between the frictional force between the paper pad P and the frictional force between the separation pad 6 and the paper feed roller 5, and separates from the original bundle P. It is possible to obtain an effect that an original other than the original to be pulled back can be pulled back by the separation pad 5.

In addition, when the feeding of the last original is completed, the separation pad 6 is moved to the position shown by the solid line by driving the sheet feeding roller 5 in the reverse direction so that the sheet feeding roller 5 and the separation pad 6 are moved. Since the interval can be widened, a large number of thick bundled originals can be easily inserted between the paper feed roller 5 and the separation pad 6 to reliably contact the paper feed roller 5, and the double feed of the original occurs. And the separation and feeding performance of the document can be further improved.

[0033]

According to the first aspect of the present invention, the pressing force of the pressing member can be adjusted depending on the insertion position of the leading end of the document bundle. It is possible to improve the sheet separation and feeding performance. According to the second aspect of the present invention, in addition to the effect of the first aspect, the frictional force between the sheet and the separation pad and the frictional force between the separation pad and the paper supply roller with the rotation of the paper supply roller. With the separation pad, the pressing member together with the separation pad is reciprocated along the outer peripheral surface of the sheet feeding roller, and sheets other than the sheet separated from the sheet bundle can be pulled back by the separation pad. As a result, the occurrence of double feeding of sheets can be more reliably prevented, and the sheet separating and feeding performance can be further improved.

According to the third aspect of the invention, in addition to the effect of the first aspect, when the feeding of the final sheet is completed, the sheet feeding roller is driven to rotate in the reverse direction to separate the sheet from the sheet feeding roller. Since the spacing between the pads can be widened, a large number of thick bundles of paper can be easily inserted between the paper feed roller and the separation pad to reliably contact the paper feed roller, resulting in double feeding of paper. Can be more reliably prevented, and the sheet separation / feeding performance can be further improved.

According to the fourth aspect of the present invention, in addition to the effect of the first aspect, the frictional force between the sheet and the separation pad and the frictional force between the separation pad and the sheet supply roller are increased with the rotation of the sheet supply roller. The pressure contact member reciprocates along the outer peripheral surface of the sheet feeding roller together with the separation pad due to the difference between the frictional force of the sheet and the separation pad, so that the sheets other than the sheet separated from the sheet bundle can be pulled back by the separation pad.

In addition, when the feeding of the final sheet is completed, the distance between the sheet feeding roller and the separation pad can be increased by driving the sheet feeding roller in the reverse direction, so that a large number of thick bundles The paper can be easily inserted between the paper feed roller and the separation pad to securely contact the paper feed roller, preventing double feeding of paper more reliably and further improving the paper separation and feeding performance. Can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of an automatic paper feeding mechanism according to the present invention, and is a schematic front view of a paper feeding section of a copying machine having the automatic paper feeding mechanism.

FIG. 2 is a top view of the automatic paper feed mechanism according to the first embodiment.

FIG. 3 is a front view of the automatic sheet feeding mechanism according to the first embodiment.

FIG. 4 is a view showing a second embodiment of the automatic sheet feeding mechanism according to the present invention, and is a schematic front view of the automatic sheet feeding mechanism.

FIG. 5 is a view showing a third embodiment of the automatic sheet feeding mechanism according to the present invention, and is a schematic front view of the automatic sheet feeding mechanism.

FIG. 6 is a view showing a fourth embodiment of the automatic sheet feeding mechanism according to the present invention, and is a schematic front view of the automatic sheet feeding mechanism.

[Explanation of symbols]

 3 Cover (pressing member support plate) 5 Paper feed roller 6 Separation pad 11 Pressing member 12 Shaft (rotation fulcrum) 13 Tension spring (Pressing force applying member) 15, 16, 17 Slot P Document bundle (paper bundle)

Claims (4)

[Claims] 1. A paper feed roller, and a separation pad extending in a paper feed direction and having a leading end pressed against an outer peripheral surface of the paper feed roller, between the paper feed roller and the separation pad. In an automatic paper feed mechanism configured to separate sheets one by one from a sheet bundle by rotating a sheet feed roller after inserting a sheet bundle, a press-contact member that presses the separation pad against a sheet feed roller is provided by a separation pad. The pressure contact member is provided so as to be swingable about a rotation fulcrum having an axis parallel to the rotation center axis of the paper feed roller, and the leading end of the pressure contact member is attached to the separation pad with a predetermined pressure around the rotation fulcrum. The rotation fulcrum includes a pressure contact member that presses the separation pad against the paper feed roller, and a pressure contact member that contacts the front end of the sheet bundle between the separation pad and the paper feed roller. It is provided between predetermined places, Automatically changing the separation pressure of the sheet bundle by the separation pad by swinging the pressure contact member about the rotation fulcrum according to the leading end position of the sheet bundle contacting between the release pad and the paper feed roller Paper feed mechanism. A shaft forming the rotation fulcrum; and a pressure contact member support plate having an elongated hole through which the shaft is inserted, wherein the elongated hole extends a predetermined length in the same direction as the outer peripheral surface of the paper feed roller. 2. The automatic sheet feeding mechanism according to claim 1, wherein And a driving means for driving the paper feed roller to rotate in a reverse direction when the feeding of the final paper is completed, and a shaft forming the rotation fulcrum is inserted therethrough to feed the paper from a predetermined position on the outer peripheral surface of the paper feed roller. A pressure contact member support plate having a long hole extending a predetermined length at a position separated from the roller, and when the feeding of the final sheet is completed, the feed roller is driven to rotate in a reverse direction to elongate the shaft. 2. The automatic paper feed mechanism according to claim 1, wherein the automatic paper feed mechanism is moved in a direction away from the paper feed roller along the hole to widen the space between the paper feed roller and the separation pad. 4. A pressing member supporting plate having a driving means for driving the paper feed roller to rotate in reverse when the feeding of the final paper is completed, a shaft constituting the rotation fulcrum, and an elongated hole through which the shaft is inserted. And a position where the elongated hole extends a predetermined length from the leading end to the trailing end in the sheet conveying direction in the same direction as the outer peripheral surface of the feed roller, and is separated from the trailing end to the outside of the feed roller. The shaft is moved in a direction away from the paper feed roller along the elongated hole by driving the paper feed roller in reverse when the feeding of the final paper is completed. 2. The automatic sheet feeding mechanism according to claim 1, wherein the distance between the sheet feeding roller and the separation pad is increased.