JPH0228431A - Paper feed device - Google Patents

Abstract

PURPOSE:To improve paper feed accuracy by fitting a torque limiter to the drive shaft of an overlapped feed prevention roller pressed to the first sheet feed roller having a one-way clutch, and the second sheet feed roller fixed to both ends of the first sheet feed roller via the shaft thereof. CONSTITUTION:A document loaded on the movable guide 201 of a document carriage device is delivered to the lowest position via the rotation of a delivery roller 212 idly coupled to the first drive shaft 210 and actuated with the second drive shaft 211 via one-way clutch 223 ana gears 224 and 225, and the second sheet feed roller 226 fixed to the drive shaft 210 at both sides thereof. Concur rently, overlapped sheet feed is prevented with an overlapped feed prevention roller 213 rotating inversely and pressed to the delivery roller 212 via a torque limiter 235. After the delivery of the lowest document, the operation of the first and second drive shafts 210 and 211 is stopped and the delivery roller 212 rotates, following up the reverse rotation of the overlapped feed prevention roller 213 via the one way clutch 223, and the second and succeeding documents are returned to the side of the movable guide 201. According to the aforesaid construction, paper feed accuracy can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a paper feeding device that separates a plurality of sheets stacked on a paper feeding tray one by one and feeds the separated sheets to a processing section. be.

[Background of the invention]

In general, sheets of paper stacked on a paper feed tray (hereinafter referred to as sheets) are fed by a feeding device to a multi-feed prevention device, where they are separated one by one and sent out.
Furthermore, the paper is fed to the processing section from the second paper feeding means l.

In such a paper feeding device, as the double feeding prevention means for preventing simultaneous feeding of two or more sheets, a sorting roller, a sorting belt, or a sorting elastic piece is used, and the leading edge of the sheet is pressed against the rotating roller surface. This prevents sheets that do not come into direct contact with the roller surface from being fed, and only one sheet is separated and sent out.

FIG. 9 is a sectional view showing an example of a conventional paper feeding device. In this paper feeding device, a double feeding prevention means is provided between the paper feeding tray 1 and the second paper feeding roller 2, and the sheets are arranged in a substantially vertical plane, and the sheets are fed out one by one starting from the top layer of the sheet bundle S. It will be done. The double feeding prevention means rotatably supports a support arm 4 having a sorting elastic piece 3 at its tip on a horizontal shaft 5,
The rear end of the support arm 4 is stretched by a spring 6 so that the sorting elastic piece 3 is brought into pressure contact with the delivery surface of the rotating roller 7.

Such conventional paper feeding devices have a long distance from the paper feeding tray to the second paper feeding roller, and require a large space. This has been a major obstacle in downsizing the main body of the paper feeder.

FIG. 1O is a sectional view showing another example of a conventional paper feeding device. In this system, the paper feeding device 20 is provided three-dimensionally above the processing section to reduce the planar space.

That is, a feed roller 22 and a paper feed port 23 are provided at the lower end of a paper feed tray 21 whose front side in the paper feed direction of the paper feed device 20 is steeply inclined downward.
A press plate 24 is swingably provided above the paper feed port 23.
A single document sent from the nearby first paper feed section (double feeding prevention means) 25 is passed from the second paper feed section 26 through the paper feed path 27 and onto the top surface of the platen glass II of the copying machine main body 10 in a U-turn shape. The document to be processed is moved to the exposure position by normal rotation of the conveyor belt 28 provided on the platen glass 11, and at that position, the exposure optical system I2 is reciprocated to perform exposure processing. Transport it outside in normal rotation. Note that the double feeding prevention means 25 of this paper feeding section [t20 is of a sheet bottom feeding type using a rotating paper feeding belt 25A and a stop roller 25B. In this paper feeding device,
Although the paper feed tray 21 does not protrude to the side of the copying machine main body 10, the second paper feed section 26 is provided downstream of the feed roller 22 and the first paper feed section 25 in the paper feeding direction. The paper feeding path becomes longer and the paper feeding device becomes larger.

[Problem that the invention seeks to solve]

In all of these conventional paper feeding devices, the feeding paper feeding section, the first paper feeding section (double feeding prevention roller), and the second paper feeding section are arranged along the paper feeding path, so the paper feeding device The paper feeding device is long and requires a large space in the height direction, which is a major obstacle in designing a smaller and thinner paper feeder.

[Means for solving problems]

In view of the above points, it is an object of the present invention to provide a paper feeding device equipped with a new double feeding prevention means and a second paper feeding means, which enables the main body to be designed to be smaller and thinner. The purpose is

In order to achieve the above object, the paper feeding device of the present invention is a paper feeding device that feeds a plurality of sheets stacked on a paper feeding tray toward a processing section one by one. a first paper feed roller whose direction is regulated; and a second paper feed roller fixed to the shaft on both sides of the first paper feed roller on the shaft of a drive shaft that loosely fits and holds the first paper feed roller. , a double feed prevention roller that is in pressure contact with the first paper feed roller, and a second paper feed driven roller that rotates while being in pressure contact with the second paper feed roller, and a torque is applied to a drive shaft that drives the double feed prevention roller. It is characterized by the provision of a limiter.

Further, in the present invention, the intended purpose can be achieved more effectively by a paper feeding device having a swingable lever member above the first paper feeding roller and the second paper feeding roller that can be brought into pressure contact with the rollers. achieved.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The paper feeding device of the present invention will be described below with reference to an embodiment of a document conveying device shown in the accompanying drawings.

FIG. 1 is a cross-sectional view of the main body of a document feeder equipped with a paper feeder according to the present invention, and FIG. 2 is a sectional view of a soft original document set in the paper feed tray of the document feeder in this document feeder just before feeding starts. FIG. 3 is a cross-sectional view of the paper feeding device showing the state immediately after the start of feeding.

In these figures, IO is the main body of the copying machine, 11 is a platen glass, 30 is a document rear end stopper plate (scale plate), and the document transport device 100 is mounted above the platen glass 11. The document conveying device 100 is attached to a hinge portion at the top of the copying machine main body IO and has a swingable structure, so that the top surface of the platen glass 11 can be opened and closed.

The document conveyance device 100 includes a paper feed section 200, a conveyance section 30,
0, and a paper discharge section 400.

The document conveying device 100 has a paper feed tray slanted at the top, consisting of a foldable movable paper feed tray 102 and a fixed paper feed tray 104 fixed to the housing body lol. Original sheets can be stacked on the tray, and the leading ends of the original sheets are inserted into the paper feed section 200. Further, a width regulating plate 103 is provided on the fixed paper feed tray 104 so as to be movable in the width direction for regulating the width when setting the document tray.

FIG. 4 is a plan view of the document feeding portion of the paper feed section 200.

The stationary paper feed tray 104 has a concave cutout near the center on the downstream side in the paper feed direction, and the concave cutout has a movable guide plate 201 or a fixed paper feed tray as shown in FIGS. The paper plate 104 can be freely swung vertically from the upper surface thereof.

That is, the lower part of the movable guide plate 201 is the swing axis 20.
It is fixed at 2. A link plate 203 is fixed to one shaft end of the swing shaft 202, and the link plate 203 is connected to one end of a solenoid link 206 via a link shaft 204 and an interrupted link 205. The solenoid link 2
The other end of 06 is the plunger 207A of the solenoid 207.
is connected to. When the solenoid 207 connected in this way is energized, the plunger 207A is attracted,
The movable guide plate 201 is swung, and its tip portion is lowered to sink below the upper surface of the fixed paper feed tray 103.

On the other hand, above the movable guide plate 201, a delivery lever 209 is swingably supported. That is, the shaft portion 209A at one end of the feed lever 209 is rotatably supported above the paper feed port 105 of the housing main body 101, and the other end is lowered by the weight of the feed lever 209 and is connected to the feed roller 212 and the second feeder. The upper surface of the stack of originals placed on the upper surface of the paper roller 226 is pressed.

When feeding a document, the movable guide plate 201 is in a raised position and is stopped slightly above the upper surface of the outer circumference of the feed roller 212. In this state, the movable paper feed tray 102,
When a document tray is set on the fixed paper feed tray 103 and pushed forward in the paper feeding direction, the leading edge of the document tray is pushed out along the upper surface of the movable guide plate 201 and is supported upward. Feed lever 209 hanging down due to its own weight
Push up the lower surface of the outer circumferential surface of the double-feed prevention roller 213 and the curved rib L0I in the housing body 101, which will be described later.
It comes into contact with A and stops. FIG. 2 is a sectional view showing this original state.

Next, on the left side of the document conveying device 100 (FIG. 1), a paper feed section 200 provided on the downstream side of the paper feed tray feeds the stack of documents inserted from above the paper feed tray into the lowest layer. A sending means (first paper feeding means) for separating and sending out sheets one by one from
and a second sheet feeding means for feeding the separated document onto the platen glass 11 of the copying machine main body IO.

This feeding means includes a feeding roller (first paper feeding roller) 212 loosely fitted into the center of the first drive shaft 210 and driven by the second driving shaft 211;
A double-feed prevention roller 213 is pivotally supported by a double-feed prevention roller mounting plate 214 provided diagonally above the double-feed prevention roller.

A drive system for the feed roller 212 and double feed prevention roller 213 is shown in FIG. FIG. 5 is a drive system diagram of the entire document adding and conveying device.

The drive shaft of the main motor 215 includes gears 216 and 217, timing pulleys 218 and 219, and a timing belt 22.
0, gear 221 coaxial with timing pulley 219, second
The second drive shaft 211 is rotated via a gear 222 that is integral with the drive shaft 211 . A gear 22 with a built-in one-way clutch 223 is provided at one shaft end of the second drive shaft 211.
It has 4. This gear 224 is connected to the first drive shaft 210.
A gear 2 that is integrated with a delivery roller 212 that is loosely fitted to the
It meshes with 25. That is, with respect to the main motor 215 which rotates in forward and reverse directions, the feed roller 212 loosely fitted to the first drive shaft 210 rotates by being transmitted with power from the second drive shaft 211 only when the main motor 215 rotates in the reverse direction. When the motor 215 rotates in the normal direction, no power is transmitted and the motor 215 rotates freely.

On the other hand, on the axis of the second drive shaft 211, on both sides of the feed roller 212, there are second paper feed rollers 226,
226 is fixed to the shaft and rotates together with the drive shaft.

Further, two gears 227 and 228 each having a built-in directional clutch and a shaft-fixed gear 229 are attached near the shaft end of the first drive shaft 210, respectively.

On the other hand, a gear 230 is fixed to the shaft end of the second drive shaft 211, and the gear 230 meshes with the gear 227 at the shaft end of the first drive shaft 210 via an idler gear 231.

In this way, the first wl driving shaft 210 and the second paper feed rollers 226 , 226 that are integrated therewith are connected to the main motor 215 .
It has the function of constantly rotating in the paper feeding direction in contrast to the forward and reverse rotation of the paper.

A gear 229 fixed to the first drive shaft 210 is connected via an idler gear 232 to a third drive shaft (torque limiter shaft) 234 having a gear 233 fixed to one shaft end.
power is transmitted to. A gear 236 having a torque limiter 235 is provided at the other shaft end of the third drive shaft 234 . The gear 236 meshes with a gear 238 which is integral with the double feed prevention roller 213 via an idler gear 237. The double feed prevention roller 213 presses against the feed roller 212 with a predetermined pressure to form a nip.

As described above, the first drive shaft 210 rotates in one direction regardless of whether the main rotor 215 rotates in the forward or reverse direction, and the double-feed prevention roller 213 coupled to the first drive shaft 210 through gears can also rotate in one direction.

@6 Figure shows the feed roller 212 and double feed prevention roller 2.
13 is a diagram illustrating a paper feeding situation according to No. 13. FIG.

First, FIG. 6(A) is a sectional view showing the arrangement of both rollers before paper feeding. The respective outer peripheries of the feed roller 212 and the double feed prevention roller 213 are provided with elastic members 212A and 213.
Covered with A. The double-feed prevention roller 213 is arranged on a spring-biased double-feed prevention roller mounting plate 214 and presses against the feed roller 212 with a predetermined spring pressure to form a nip N. Note that the friction coefficient of the surface of the elastic member 212A of the feed roller 212 is set to be higher than that of the surface of the elastic member 213A of the double-feed prevention roller 213, and the relative frictional force when the rollers on both sides are pressed together is Fl. shall be.

The feed roller 21 is driven by the main motor 215.
2 rotates in the normal direction with respect to the paper feeding direction, and the double-feed prevention roller 213 that is in pressure contact with this roller is subject to the relative frictional force F1 and the setting force F of the torque limiter 235. This prevents rotation and maintains the stopped state.

FIG. 6(B) is a diagram showing a state in which one original document is fed. A sheet of document held between the forward-rotating feed-out roller 212 and the feed-out lever 209 is pressed against the double-feed prevention roller 213 and the feed-out roller 212 at the nip N position.
The relative frictional force F2 between the double feed prevention roller 213 and the back surface of the document tray is set to be larger than the relative frictional force F between the double feed prevention roller 213 and the front surface of the document tray (F2>F3), and the trilimiter 23
5 setting force F. Since is larger than F3 (Fo>Ft),
The fed-in original document is wound around the outer periphery of the feed-out roller 212 and is fed out through the nip position at the same circumferential speed. At this time, the double-feed prevention rollers 2+3, which are in pressure contact with the front side of the document tray, rotate in the document feeding direction without slipping.

FIG. 6(C) shows a plurality of originals, for example two originals D1,
It is an explanatory view showing a state where D2 and D2 are fed into the nip position at the same time. Here, if the frictional force between the two originals at the second lug position is F4, then F 2 > F o > F 3 > F *, so the lower original D1 that comes into pressure contact with the feed roller 212 is fed as is. However, since the double-feed prevention roller 213 rotates in the opposite direction to the paper feeding direction, the upper document D2 that follows in pressure contact with the double-feed prevention roller 213 slips with W and the document D1 and is returned in the opposite direction. It will be done.

FIG. 6(D) is an explanatory diagram showing the behavior of the document D1 that has passed through the nip position and the document D2 that has been returned. When multiple documents are fed into the nip position at the same time in this way, only one document that is in pressure contact with the feed roller 212 is fed in the forward direction (bottom feed), or all other documents are fed in the reverse direction. This prevents double feeding, such as double feeding. That is, the frictional force between the original document tray and the double-feeding prevention roller 213 is larger than the frictional force between the originals, and a wedge shape is formed between the feed roller 212 and the double-feeding prevention roller 213 from the entrance of the nip N. Therefore, the upper original D2 is prevented from moving forward, and only the lower original D1 moves forward while sliding on the upper original, thereby performing one-sheet feeding of the original.

In addition, the above-mentioned feed roller 2+2 and double feed prevention roller 21
3, the second paper feed rollers 226, 226, which are fixed to the first drive shaft 210 that loosely supports the feed roller 212, also rotate in the same direction at the same speed as the feed roller 212. It plays an auxiliary role in feeding the document in a U-turn.

The second paper feeding means of the paper feeding means 200 is connected to the first drive shaft 21.
Two second paper feed rollers 226, 226 are fixed to both sides of the feed roller 2i2 which is loosely fitted into the feed roller 2i2, and driven rollers 240, 240 are press-contacted to the lower surface side of the rollers 226, 226 so as to be rotatable. It has become.

The second paper feed rollers 226 and 226 have the same diameter as the #double feed roller 212, and
When the feed roller 212 rotates, it rotates in the same direction so as not to interfere with the feed of the document.

The driven rollers 240 and 240 are, as shown in FIG.
40C, and due to the elasticity of the roller mounting plate, the roller 240A
is always in pressure contact with the second paper feed roller 226.

FIG. 7 is a cross-sectional view showing the suspended and press-contact state of the drive system of the double-feed prevention roller 213 and the press-contact state of the second paper feed driven roller 240.

The driven roller 24 is connected to the feed roller 212, double feed prevention roller 213, and the conveyance path downstream of the nip position.
A document detection sensor 241 is provided near the pressure contact position 0. (See Figures 2 and 3) The document detection sensor 2
41 is turned ON when the leading edge of one document separated and sent out at the nip position passes through the W and document stack (see Fig. 3).
When the trailing edge of the document tray passes, it becomes 0FF (see FIG. 2). This document detection sensor 241
are photo interrupter 241A, actuator shaft 24
1B! A movable actuator 24IC and an actuator spring 24 that biases the actuator 241C.
Consists of 1D.

Next, the paper feeding and conveying operation will be explained according to the timing chart of FIG. When the document detection sump 241 detects the leading edge of the document (see FIG. 3), the solenoid 207 is turned off after a certain period of time after generating the detection signal.
Each member of the link mechanism 202, 203, 204, 20
5, 206 to raise the movable guide plate 201.

At the same time, the main motor 215 shifts from reverse rotation to forward rotation, or at this time, the gear 230 of the second drive shaft 211, the idler gear 232, and the one-way clutch 227A
The first drive shaft 210 continues to rotate in the same direction via the gear 227 containing the one-way clutch 228A (rotation is not transmitted to the gear 228 containing the one-way clutch 228A),
A second paper feed roller 226 fixed to the shaft 210 also continuously rotates in the same direction.

However, as the main motor 215 shifts to forward rotation, the second drive shaft 211 also shifts from reverse rotation to forward rotation, or the gear 224 is rotated by 7υ by the one-sided clutch 223 provided at the shaft end of the second drive shaft 211. After one rotation, the gear 225 that meshes with the gear 225 and the delivery roller 212 that is integral with the gear 225 no longer transmit rotation.

Here, when the leading edge of the document is pressed and held between the second paper feed roller 226 and the driven roller 240, the feed roller 212 rotates freely and the second paper feed roller 226 rotates forward.
The document paper tightly wound around the paper feed roller 212 is driven to rotate in the paper feeding direction.

Note that since the first drive shaft 210 continues to rotate in the normal direction, the double-feed prevention roller 213 continues to rotate in the normal direction to prevent double feeding of the second and subsequent documents and return them. Further, the second paper feed roller 226 continues to rotate after that, and the separated paper feed roller 226 continues to rotate.
Continue to feed sheets of original paper.

When the trailing edge of the document being fed passes the document detection sensor 241 and a trailing edge detection signal is generated, a certain number of pulses are counted, the document @D is detected by the conveyance roller 301 of the conveyance section 300 shown in FIG. , 302.303, platen glass l
The trailing edge of the document tray passes through the trailing edge stopper (abutting plate) 30.

When this number of pulses is counted up, the main motor 2
15 is changed from normal rotation to reverse rotation again, and the second paper feed roller 2
The document tray 26 is slightly reversed and the rear end of the document tray is abutted against the abutment plate 30, so that the document tray is set at a predetermined position on the platen glass 11.

Thereafter, after a predetermined pulse count, the white sheet member 304 presses the document against the platen glass 11, and exposure scanning and image forming processing of the document are subsequently started within the copying machine main body 10. After completing the exposure scan, the document passes through the conveyance section 300 and is moved to the paper ejection roller 401 of the paper ejection section 400,
The sheet is pressed and pinched by pinch rollers 402 and 403 and discharged, and placed on an external sheet discharge tray 106.

Paper discharge sensor 40 provided in the conveyance path of the paper discharge section 400
4, when the leading edge or trailing edge of the document is detected,
The feeding operation for the second and subsequent documents is repeated in the same manner as above.

The paper feeding device of the present invention is not limited to the embodiment of the document conveying device described above, but is capable of automatically feeding a plurality of sheets stacked on a paper feeding tray and making a U-turn one by one. The present invention can be widely applied to an automatic sheet feeding device that feeds sheets to a processing section, and a semi-automatic sheet feeding device that manually feeds sheets on a sheet feeding tray one by one in a U-turn and sends them to a processing section.

〔Effect of the invention〕

As described above, the paper feeding device of the present invention has a one-way clutch in the paper feeding device that feeds a plurality of sheets stacked on a paper feeding tray toward a processing section one by one. 1st
A paper feed roller, a second paper feed roller that is coaxially fixed to the rotation axis of the first paper feed roller and near both ends of the first paper feed roller, and a double feed roller that is in pressure contact with the first paper feed roller. It is characterized by comprising a prevention roller and a second paper feed driven roller that rotates in pressure contact with the second paper feed roller, and a torque limiter is provided on the drive shaft that drives the double feed prevention roller, The present invention is characterized in that a lever member that can swing freely in pressure contact with both rollers is provided above the first paper feed roller and the second paper feed roller. The paper roller and the second paper feed roller work in pressure contact with the feed lever to orderly feed the fed sheets (original documents, etc.) to the double feed position to prevent double feeding, thereby causing folded edges and wrinkles of the sheets. This is extremely effective in improving paper feeding accuracy without causing double feeding or jams until the last sheet is sent out.

In addition, in conventional paper feeding devices, the feed section, double feed prevention section,
In the paper feeding device of the present invention, the second paper feeding section is composed of three parts, and the above three parts are put together on the l axis, and the fed sheet is made a U-turn and conveyed to the processing section. This makes it possible to make the paper feeding device smaller and thinner, and
The excellent effects of reducing cost and improving reliability can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the main body of a document conveying device equipped with a paper feeding device according to the present invention, and FIGS.
A sectional view of the paper feeding means, FIG. 4 is a partial plan view of the paper feeding section, and FIG.
The figure is a drive system diagram of the entire document conveying device, Figure 6 is an explanatory diagram of the double feeding prevention operation, Figure 7 is a sectional view of the second paper feeding means, Figure 8 is a timing chart of paper feeding, Figure 9 and FIG. 1O is a sectional view of a conventional paper feeding device. DESCRIPTION OF SYMBOLS 100... Original conveyance device 101... Housing main body 102... Movable circular paper tray 104... Fixed paper feed tray 200... Paper feeding section 201... Movable guide plate 207... Solenoid 209... Feeding Lever 210...First drive shaft 211...Second drive shaft 212...Feeding roller (first paper feed roller) 21
3... Double feed prevention rollers 223, 227A, 228A... One-way clutch 226... Second paper feed roller

Claims (2)

[Claims] (1) In a paper feeding device that feeds multiple sheets stacked on a paper feeding tray toward a processing section one by one, a first paper feeding roller whose driving rotation direction is regulated by a one-way clutch; , a second paper feed roller fixed to the shaft on both sides of the first paper feed roller on the shaft of the drive shaft that loosely holds the first paper feed roller, and a weight that presses against the first paper feed roller. A sheet feeder comprising a feed prevention roller and a second sheet feed driven roller that rotates in pressure contact with the second sheet feed roller, and a torque limiter is provided on a drive shaft that drives the double feed prevention roller. Device. (2) The paper feed device according to claim 1, further comprising a swingable lever member above the first paper feed roller and the second paper feed roller that can be brought into pressure contact with both rollers.