JPH02138041A - Sheet supply device - Google Patents

Abstract

PURPOSE:To eliminate frictional sound due to friction between a sheet and a friction pad by releasing pressure welding of the friction pad to a sheet supplying roller when the sheet supplied by the sheet supplying roller is nipped by rollers on the following process-step. CONSTITUTION:When sheets 10 are conveyed and a sheet is nipped, for example, by a platen roller and others on the following process-step, a friction pad 23 is moved to a second position, and pressure welding to a sheet supplying roller 21 is released. Since there is no load due to pressure welding of the platen roller to the friction pad 23, frictional sound or image delay caused by the friction pad 25 is eliminated. Further, when the friction pad 23 is moved to the second position, a regulating member 26 is also moved to the second position, and the tip of the regulating member abuts on the sheet supplying roller 21. The conveyance of the sheets 10 except sheets being on the course of conveyance is thus regulated, and thereby multi-sheets feed can be positively prevented even when pressure welding of the friction pad 23 is released.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding device for feeding sheets one by one from a paper storage section storing a large number of sheets to a paper receiving section.

[Conventional technology]

2. Description of the Related Art Copying machines and facsimile machines are provided with a paper feeding device for feeding paper such as manuscripts and recording paper into the main body of the apparatus. This paper feeding device is provided with a double-feed prevention mechanism to prevent two or more sheets from being conveyed in an overlapping manner.

For example, in the double feeding mechanism disclosed in Japanese Utility Model Application Publication No. 62-65440, a paper feed roller is arranged near the exit of the paper storage section, and a rubber friction pad is in contact with this paper feed roller to cause friction. The pad is pressed against the paper feed roller by a plate spring or the like. Then, the paper is transported by the paper feed roller, but the double-fed paper is caused by differences in the friction coefficient between the friction pad and the paper, the friction coefficient between the papers, and the friction coefficient between the paper and the paper feed roller. , only the paper on the paper feed roller side is conveyed. In this way, the sheets of paper in the paper storage section are conveyed one by one to the main body of the apparatus, such as a facsimile machine.

[Problem to be solved by the invention]

In conventional paper feeding devices such as those mentioned above, paper is fed by pressing a friction pad made of rubber against the paper feeding roller, so friction between the rubber and the paper is unavoidable. A problem arises in that noise is generated between the paper and the paper.

Furthermore, in a facsimile machine, for example, the paper conveyed by the paper feed roller is nipped by a platen roller for image reading disposed on the downstream side in the conveyance direction, and is conveyed to an image information reading section at a predetermined timing. At this time, while the leading edge of the paper is nipped by the platen roller, the trailing edge is still nipped by the paper feed roller and the friction pad.

Therefore, the pressure of the friction pad becomes a load on the feed of the platen roller, which may cause slippage in the feed of the platen roller, resulting in image delay. In devices where the paper feed roller is constantly driven, the rotation speeds of the platen roller and paper feed roller are different in order to provide a predetermined interval between sheets that are continuously conveyed, and the platen roller is rotated at different speeds. is rotating at about twice the speed. When there is a difference in rotational speed between the platen roller and the paper feed roller as described above, the pressure contact of the friction pad is likely to cause a load on the platen roller, and the above-mentioned image delay problem is likely to occur.

Furthermore, the conventional example described above has a problem in that prevention of double feeding is insufficient.

An object of the present invention is to provide a paper feeding device that can prevent noise caused by friction pads during paper feeding, prevent double feeding mechanisms such as friction pads from becoming a load on the paper conveyance system, and reliably prevent double feeding. Our goal is to provide the following.

[Means to solve the problem]

The paper feeding device according to the present invention is a paper feeding device for feeding paper one by one from a paper storage section storing a large number of sheets to a paper receiving section, and the paper feeding device is a paper feeding device for feeding paper sheets one by one from a paper storage section storing a large number of sheets to a paper receiving section. The paper feed roller includes a paper feed roller that conveys the paper, a friction pad disposed opposite to the paper feed roller, a regulating member, and a position control means that controls the positions of the friction pad and the regulating member.

The friction pad is configured to be able to take a first position in which it is pressed against the paper feed roller and a second position in which the pressure contact is released. The regulating member is
A first position in which the leading edge is separated from the paper feed roller to enable conveyance of the paper, and a first position in which the leading edge abuts against the paper feed roller in order to restrict the conveyance of paper other than the paper being conveyed. and a second position.

Further, the position control means controls the positions of the friction pad and the regulating member according to the conveyance position of the paper.

[Effect]

In this invention, the paper is conveyed from the paper storage section to the supplied section by rotation of the paper feed roller.

At this time, the friction pad is in the first position and is in pressure contact with the paper feed roller. Further, the regulating member is in the first position and is separated from the paper feed roller so that the paper can be conveyed. Therefore, in this state, double feeding is prevented by the friction pad and sheets are conveyed one by one by the same function as in a conventional paper feeding device.

On the other hand, when the paper is conveyed and nipped, for example, by the next platen roller, the friction pad moves to the second position,
Pressure contact with the paper feed roller is released.

Therefore, the load caused by the pressure contact of the friction pad of the platen roller is eliminated, and the noise caused by the friction pad is eliminated.
Image delay is eliminated. Furthermore, the friction pad is a second friction pad.
When moving to the position, the regulating member has moved to the second position, and its tip is in contact with the paper feed roller. This restricts the conveyance of sheets other than those being conveyed, and even if the pressure contact of the friction pad is released, double feeding is reliably prevented.

〔Example〕

FIG. 3 is a cross-sectional configuration diagram of a facsimile machine in which a paper feeding device according to an embodiment of the present invention is applied. In FIG. 3, a facsimile machine main body 1 mainly includes a recording section 2 and a reading section 3 disposed above it. It is supposed to be paper. Furthermore, an ejection tray 4 from which recording sheets and original documents are ejected is attached to the side of the facsimile apparatus main body 1.

The recording unit 2 is provided with a thermal head 6 for printing received information on thermal paper 5. A printing roller 7 is arranged below the thermal head 6, and between the thermal head 6 and the printing roller 7, the leading end of the thermal paper 5, which is wound into a roll and stored in the facsimile machine main body 1, is placed between the thermal head 6 and the printing roller 7. It is designed to be inserted. A conveyance path 8 is provided downstream of the thermal head 6, and further downstream of this conveyance path 8, a pair of upper and lower discharge rollers 9 are arranged.

The reading section 3 is provided with a light source 11, mirrors 12a to 12c, and a CCD unit 13 for reading image information on the original 10. A document transport path 14 is provided between the reading unit 3 and the paper feeder 20, and a timing switch 15 is provided in the document transport path 14 to drive and control each member of the paper feeder 20, which will be described later. ing. Further, on the upstream side of the timing switch 15, a reading roller 16 is arranged for conveying the original IO to the reading section 3 at a predetermined timing.

The upper surface of the facsimile main body 1 also serves as a mounting table for the document 10, and a document stack 17 is formed at the leading end in the conveyance direction. Further, a document guide 18 is attached to the upper end of the main body 1. Note that a power supply unit 19 is disposed on the right side of the main body 1 in the drawing.

Next, details of the paper feeding device 20 will be explained with reference to FIGS. 1 and 2. In this paper feeding device 20, the original 10 is placed on the original holding table formed on the upper surface of the facsimile main body 1, as described above. A paper feed roller 21 is arranged at the downstream end of the document table in the conveyance direction, and this paper feed roller 21 is fixed to a shaft 22 connected to a drive system. A friction pad 23 is arranged above the paper feed roller 21 to face it.

The friction pad 23 is made of rubber or the like with a high friction coefficient, as in the conventional case. Further, the friction pad 23 is fixed to the lower surface of one end side of the support plate 24 which is shaped like an F when viewed from the side. The support plate 24 has a bracket portion 24a projecting upward at approximately the center thereof, and this bracket portion 24a is rotatably mounted on the support shaft 33.

Furthermore, on the upper surface of the support plate 24, on the side where the friction pad 23 is fixed, together with a torsion spring 31,
A pressing plate spring 25 for pressing the friction pad 23 against the paper feed roller 21 is fixed. This pressing plate spring 25 has a base 25a on one end side fixed to a substantially central portion of the support plate 24, extends from this base 25a in a substantially horizontal direction toward the conveyance direction, and extends from the base 25a at the first bending portion 2.
5b is bent approximately 90'' downward and comes into contact with the friction pad 23, and further is bent 90 degrees in the direction away from the friction pad at the second bent portion 25c which is in contact with the friction pad 23. The other end side of the torsion spring 31 is
It is supported on the lower surface of the apparatus main body frame (not shown).

Further, on both left and right sides of the friction pad 23, regulating plate springs 26 are provided for regulating the conveyance of paper other than the paper being conveyed.
is provided. This regulating plate spring 26 is fixed to one end side of a support plate 27 (hereinafter referred to as a regulating support plate) that is shaped like a letter when viewed from the side. Like the friction pad support plate 24, the regulation support plate 27 has a bracket portion 27a formed approximately in the center thereof and protrudes upward, and this bracket portion 27a is rotatably attached to the support shaft 33. It is installed. The regulating plate spring 26 is formed in an L-shape when viewed from the side, and its long side is fixed to the regulating support plate 27, and its short side is bent approximately 90 degrees downward from the long side. The tip of the part is
It can come into contact with the paper feed roller 21 side. In addition, 32
is a torsion spring for pressing the regulating plate spring 26 against the paper feed roller 21. The other end side of this torsion spring 32 is supported by the lower surface of the frame of the main body of the apparatus, like the torsion spring 31 described above.

The other end of the friction pad support plate 24 and the regulation support plate 27, that is, the upstream end in the conveyance direction, is
They are in contact with the friction pad driving cam 28 and the regulating plate spring driving cam 29, respectively. These cams 28.29
As shown in FIG. 2, approximately 1/2 of the circumference is the inside of the foundation A, and the remaining 1/2 of the circumference is the transition part B and the lift part C. Then, from the inside of the foundation A to the lift part C, there is a gradual transition via the transition part B, but from the end of the lift part C to the inside of the foundation A, there is a contour curve that suddenly transitions at the - point position. ing. Also, cam 28 and cam 2
9 is fixed to the camshaft 30 with a phase difference of 180''.The camshaft 30 is connected to a drive system via a clutch mechanism (not shown).

With the above configuration, the cams 28 and 29 rotate,
The friction pad 23 can take a first position where it is in pressure contact with the paper feed roller 21 and a second position where it is away from the paper feed roller 21, and the regulating plate spring 26 has its tip It can take a first position where it is away from the paper feed roller 21 and allows the paper to be conveyed, and a second position where it comes into contact with the paper feed roller 21 and restricts the conveyance of the paper except when it is being conveyed. It looks like this.

Next, the operation will be explained.

When the document 10 is set on the placing table and a transmission operation is performed, the document reading unit 3
Paper is fed to When the document is fed, the timing switch 15 detects the conveyance position of the document, and the rotation of the camshaft 30 is controlled according to the detection result. This rotation is controlled by turning on and off a clutch mechanism (not shown).

Now, when the first document is fed, the rotational position of the camshaft 30 is 180 degrees different from the rotational position shown in FIG. has stopped. In this case, the other end side of the friction pad support plate 24 is in contact with the base interior A of the cam 2B, and therefore the support plate 24 is in contact with the torsion spring 31.
Due to the biasing force of the pressing plate spring 25, a rotational force is applied in a counterclockwise direction around the support shaft 33. As a result, the friction pad 23 is pressed against the paper feed roller 21. On the other hand, the other end side of the regulating support plate 27 is in contact with the lift portion C of the cam 29. Therefore, the support plate 27 is
It rotates clockwise against the urging force of the torsion spring 32, and the tip of the regulating leaf spring 26 is separated from the paper feed roller 21, so that the document can be transported.

The feeding of the original in this state is similar to that of a conventional paper feeding device, and there are differences in the friction coefficient between the friction pad 23 and the original, the friction coefficient between the originals, and the friction coefficient between the original and the paper feed roller 21. This prevents double feeding of originals, and the originals on the mounting table are fed one by one starting from the lowest one.

When the document is nipped by the reading rollers 16 and further transported and detected by the timing switch 15, the clutch mechanism is turned on in response to the detection result, and the camshaft 30 is rotated counterclockwise. Then, first, the surface of the cam 29 that the regulating support plate 27 is in contact with moves from the end of the lift portion C to the inside of the foundation A, so that the regulating support plate 27 is moved counterclockwise by the biasing force of the torsion spring 32. Rotate. Then, the tip of the regulating leaf spring 26 is
Due to the biasing force, it comes into contact with the top surface of the document being transported (
(state shown in FIG. 2). Therefore, only the lowest document is conveyed by the paper feed roller 21, and the conveyance of the documents above it is regulated.

On the other hand, after a predetermined period of time after the regulation leaf spring 26 has descended,
Cam 28 with which the friction pad support plate 24 is in contact
The surface moves from the foundation interior A to the transition section B, and then to the lift section C. As a result, the support plate 27
The friction pad 23 rotates clockwise against the biasing force of the torsion spring 31, and the friction pad 23 becomes separated from the paper feed roller 21.

Note that, at this time, the conveyance of the document is regulated by the regulating plate spring 26 as described above.

In this manner, with the regulating plate spring 26 in contact with the paper feed roller 21 to regulate the conveyance of the document, and with the friction pad 23 separated from the paper feed roller 21, the clutch mechanism provided on the camshaft 30 is activated. The camshaft 30 is turned off and the rotation of the camshaft 30 is stopped.

In this state, the document is not pressed against the paper feed roller 21 side by the friction pad 23, so there is no load on the reading roller 16 side, the document is smoothly conveyed to the reading section 3, and there is no delay in the image. etc. will not occur. Furthermore, noise caused by friction between the friction pad 23 and the document is eliminated.

Further, although the friction pad 23 is separated from the paper feed roller 21, the regulating plate spring 26 reliably prevents double feeding of documents.

When the timing switch 15 detects the document and a predetermined period of time has elapsed, it is assumed that the trailing edge of the document has passed the paper feed roller 21 portion, and the next operation is started. That is, the camshaft 3
0 clutch mechanism is turned on, and the camshaft 30 rotates.

Due to this rotation, first, the friction pad support plate 24
The surface of the cam 28 that the other end is in contact with moves from the end of the lift portion C to the inside of the foundation A. As a result, the support plate 24 rotates counterclockwise, and the friction pad 23 is pressed against the paper feed roller 21 by the urging force of the torsion spring 31 and the pressing leaf spring 25.

After landing of this friction pad 23, the regulating support plate 27
The surface of the cam 29 that is in contact with the cam 29 moves from the base interior A to the lift section C via the transition section B.

Therefore, the support plate 27 rotates clockwise, and the tip of the regulating plate spring 26 rises and separates from the paper feed roller 21. This allows the document to be transported.

Thereafter, the same operation is repeated, and when the document is in a position where it is nipped by both the reading roller 16 and the paper feed roller 21, the pressure contact of the friction pad 23 against the paper feed roller 21 is released, and A regulating plate spring 26 regulates the conveyance of the document. Further, when the paper is not sufficiently nipped by the reading roller 16, the friction pad 23 is pressed against the paper feed roller 21, and the regulating plate spring 26
is located away from the paper feed roller 21 so that the document can be transported.

Note that the polling operation, document reading operation, transmission operation, and recording operation upon reception of the facsimile apparatus itself are performed in the same manner as in the conventional case.

[Other Examples]

In the embodiment, the friction pad 23 and the regulating plate spring 26
The position control of each support plate) 24, 27 and cam 28
．． 29, but the mechanism for position control is not limited to the configuration of the above embodiment. For example, an actuator is connected to each member and the actuators are operated independently to perform position control. You can do it like this.

Further, the present invention can be applied not only to the facsimile machine as in the embodiment described above, but also to the paper feeding section of a copying machine.

[Effects of the Invention] As described above, according to the present invention, when the paper fed by the paper feed roller is nipped by the next roller,
Since the pressure contact of the friction pad against the paper feed roller is released, the noise caused by RT friction between the paper and the friction pad is eliminated, and the load on the next stage roller is reduced.
Image delays due to sheet misalignment are eliminated, and the temperature rise of the motor that drives the next stage roller is also reduced.

In addition, since a regulating member is provided to release the pressure contact of the friction pad against the paper feed roller and to regulate the conveyance of paper, double feeding of paper can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a paper feeding device according to an embodiment of the present invention, FIG. 2 is a side sectional view thereof, and FIG. 3 is a sectional configuration diagram when the paper feeding device is applied to a facsimile machine. 0... Original, 15... Timing switch, 16
...Reading roller, 20...Paper feeder, 21...
-Paper feed roller, 23...Friction pad, 24...Support plate, 25...Press plate spring, 26...Regulation plate spring, 27...Support plate, 28.29... Cam, 30...12 force axes, 31.32...Torsion spring. Patent applicant Mita Kogyo Co., Ltd. Agent Patent attorney Ono Yamakio Agent Patent attorney Yoshio Miyagawa 1δ [1 Figure

Claims (1)

[Claims] (1) A paper feeding device for feeding sheets of paper one by one from a paper storage section storing a large number of sheets to a paper receiving section, which is disposed near an exit of the paper storage section and is connected to the paper storage section. a paper feed roller that conveys the lowest stacked paper; a first position that is disposed opposite to the paper feed roller and is in pressure contact with the paper feed roller; and a first position in which the pressure contact with the paper feed roller is released. a friction pad configured to assume a second position in which the paper is conveyed;
A first position where the leading edge is away from the paper feed roller and a second position where the leading edge is in contact with the paper feeding roller in order to restrict the conveyance of paper other than the paper being conveyed. A paper feeding device comprising: a regulating member configured as described above; and a position control means for controlling the positions of the friction pad and the regulating member according to the transport position of the paper.