JPH0228432A - Paper feed device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of improper paper feed by providing a lever member above the first sheet feed roller in press contact with an overlapped feed prevention roller ana having a one-way clutch and the second sheet feed roller in such a way as to oscillate freely, and pressing a sheet with the own weight of the lever member. CONSTITUTION:A document group D loaded on a movable guide plate 201 comes down upon the start of feed due to the operation of a solenoid 207, and comes in contact with a delivery roller 212 idly coupled to the first drive shaft 210 and the external surface of the second sheet feed roller 226 fixed to both sides thereof. Furthermore, the group D is pressed with the own weight of a lever member 209 so provided above as to be capable of free oscillation. ln addition, the delivery roller 212 is rotated with the second drive shaft and the second sheet feed roller 226 is rotated with the first drive shaft 210 respectively in a forward direction via a one way clutch, thereby feeding the lowest sheet and reversing an overlapped feed prevention roller 215 pressed to the delivery roller 212 for feeding sheets one by one. According to the aforesaid construction, it is possible to prevent the occurrence of improper paper feed such as a jam and a bent edge.

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 by the second paper feeding means.

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 l 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. 10 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 out 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 to the upper surface of the platen glass 11 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 12 is reciprocated to perform exposure processing. Transport it outside in normal rotation. Note that the double feeding prevention means 25 of this paper feeding device 20 is of a sheet bottom feeding type using a rotating paper feeding belt 25A and a stop roller 25B. In this paper feeding device, the paper feeding tray 21 does not protrude to the side of the copying machine main body IO, but the second paper feeding section 26 is located downstream of the feed roller 22 and the first paper feeding section 25 in the paper feeding direction. , the paper feeding path becomes long and the paper feeding device becomes large.

[Problem that the invention seeks to solve]

In all of these conventional paper feeding devices, the first paper feeding section (double feed prevention roller) and the second paper feeding section are arranged along the paper feeding path, making the paper feeding device long and large. It also requires a large space in the height direction, which has been a major obstacle in designing smaller and thinner paper feeders. Further, in the paper feeding device, the spring urging force for feeding varies depending on the number of sheets to be fed, and an appropriate pressing force is not maintained, often resulting in paper feeding failure.

[Means for solving problems]

In view of the above-mentioned points, an object of the present invention is to provide a paper feeding device equipped with a novel sheet feeding means in which the main body can be designed to be smaller and thinner, and also to realize stable paper feeding. It is said that

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; second paper feed rollers 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; a swingable lever member is provided above the first paper feed roller and the second paper feed roller; This apparatus is characterized in that it is configured to press the paper feeding outer peripheral surfaces of the first paper feeding roller and the second paper feeding roller.

Further, the swinging rotation axis of the lever member is provided above in the upstream direction of paper feeding, and the sheet pressing position of the lever member is set in the vicinity of the pressure contact position of the double feeding prevention roller in the downstream direction of paper feeding, so that a predetermined pressure contact load is applied. This is effectively achieved by the paper feeding device of the present invention, which is characterized in that it is configured in a trail format.

〔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, 10 is a main body of the copying machine, 11 is a platen glass, 30 is a document trailing edge stopper plate (scale plate), and the document conveying device 100 is mounted above the platen glass 11. The document conveyance device 100 is attached to a hinge portion at the top of the copying machine main body 10 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, which is composed of a foldable movable paper feeder 102 and a fixed paper feed tray 104 fixed to the housing body 101. Original sheets can be placed in a stacked manner, 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 fixed paper feed tray 104 has a concave cutout near the center on the downstream side in the paper feed direction, and a movable guide plate 201 is fixed to the concave cutout as shown in FIGS. 2 to 4. It is freely swingable in the vertical direction from the upper surface of the paper feed tray 104. That is, the lower end of the movable guide plate 201 is connected to the swing shaft 2.
It is fixed at 02. 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 other end of the solenoid link 206 is connected to the plunger 207 of the solenoid 207.
Connected to A. 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 is lowered.
It sinks below the upper surface of the fixed paper feed tray 103.

On the other hand, above the movable guide plate 201, a delivery lever (lever member) 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 body 101, and the other end hangs down in the downstream direction of paper feed, and is lowered by the weight of the feed lever 209. , press the top surface of the document tray with a constant load. Supported in this way, the feed lever 209 always presses the original with its own weight even if the amount of stacked originals changes, and no load fluctuation occurs. Note that the load P applied to the document at the time of feeding was set to approximately 30 gr.

When feeding a document, the movable guide plate 201 is in a raised position and is stopped slightly above the outer circumferential upper surface of the feed roller 212. In this state, when a document tray is set on the movable paper feeder 102 and the fixed paper feed tray 103 and the document tray is 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. At the same time, the lower surface of the feed lever 209, which is supported above and hangs down due to its own weight, is pushed up and comes into contact with the outer circumferential surface of a double feed prevention roller 213, which will be described later, and the lip 10IA surface of the housing body 101, and stops.

FIG. 2 is a sectional view showing this document set state.

When setting the document, the feed lever 209 also serves as a guide plate for pressing and correcting the curling of the document and inserting the document.

Next, the paper feed unit 200 provided on the left side of the document conveying device 100 (FIG. 1) and downstream of the paper feed I-ray is
A sending means (first paper feeding means) for separating and sending out a stack of originals inserted from the top of the paper feed tray one by one from the bottom layer, and a platen glass of the copying machine main unit 10 for sending the separated originals one by one from the bottom layer. and a second paper feeding means for feeding paper onto the paper.

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 conveying device.

The drive shaft of the main motor 215 includes gears 216 and 217, timing pulleys 2]8 and 219, and a timing belt 22.
0, gear 2211 second coaxial with timing pulley 219
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 front north 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, second paper feed rollers 226.2 are provided on both sides of the feed roller 212, respectively.
26 is fixed to the shaft and rotates together with the drive shaft.

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

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.

Thus, the first drive shaft 210 and the second paper feed rollers 226 and 226 integral therewith have the function of constantly rotating in the paper feeding direction in response to the forward and reverse rotations of the main motor 215.

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 is pressed 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.

FIG. 6 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. The coefficient of friction on the surface of the elastic member 212A of the feed roller 212 is set to be larger than the coefficient of friction on 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 against each other is expressed as Fl. do.

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 rotates due to the above-mentioned relative frictional force F.

The rotation is prevented by the setting force F0 of the torque limiter 235, and the stopped state is maintained.

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 F3 between the double feed prevention roller 213 and the front surface of the document tray (F2>F,), and the trilimiter 23
Since the setting force F0 of 5 is larger than F3 (Fo>F,),
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 roller 213, which is in pressure contact with the front side of the document tray, rotates in the document feeding direction without slipping.

FIG. 6(C) shows a plurality of manuscripts, for example two manuscripts,
It is an explanatory view showing a state where D and D are sent into the nip position at the same time. Here, if the frictional force between the two originals at the nip position is F4, then F 2 > F O > F 3 > F 4 , so the lower * in pressure contact with the feed roller 212
[D, is fed in the paper feeding direction as it is, but since the double feed prevention roller 213 rotates in the opposite direction to the paper feeding direction, the upper document D2, which follows in pressure contact with this roller, slips with the document D1. returned in the opposite direction.

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. In this way, when multiple documents are fed into the nip position at the same time, only one document that is in pressure contact with the feed roller 212 is fed in the forward direction (bottom feed), but all other documents are fed in the reverse direction. This prevents double feeding, such as double feeding.

Note that the above-mentioned feed roller 212 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 212 which is loosely fitted into the feed roller 212, and driven rollers 240, 240 are pressed against the lower surface of the rollers 226, 226 so as to be rotatable. It is made.

The second paper feed rollers 226, 226 have the same diameter as the feed roller 212, and have the same diameter as the feed roller 212.
2, 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, 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.

The driven roller 2
A document detection sensor 241 is provided near the pressure contact position 40 . (See FIGS. 2 and 3) The document detection sensor 241 is turned on when the leading edge of one document separated and sent out at the nip position among the document bundle passes (see FIG. 3).
When the rear end of the document tray passes, the switch is turned off (see Fig. 2). This document detection sensor 24
1 is a photo interrupter 241A, actuator shaft 2
41B, a swingable actuator 241C, 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 sensor 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, but 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, but the gear 224 is freed by the one-way clutch 223 provided at the shaft end of the second drive shaft 211. As a result, rotation is no longer transmitted to the gear 225 that meshes with the gear 225 and the delivery roller 212 that is integral with the gear 225.

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 certain number of pulses are counted after generating a trailing edge detection signal, the document is transferred to the conveyance roller 301 of the conveyance section 300 shown in FIG. 302 and 303, platen glass 1
1, and the rear end of the document tray passes through the document rear end 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 abutting 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. The document after exposure scanning is transported to the transport section 30.
0, the paper ejection roller 4011 of the paper ejection unit 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, in the paper feeding device of the present invention, the first paper feeding roller feeds a plurality of sheets stacked on a paper feeding tray one by one toward the processing section. and the second
A swingable lever member is provided above the paper feed roller, and the lever member's own weight presses the paper feed outer peripheral surfaces of the first paper feed roller and the second paper feed roller. Further, the swinging rotation axis of the lever member is provided above in the upstream direction of paper feeding, and the sheet pressing position of the lever member is set at a predetermined position near the pressure contact position of the double feeding prevention roller in the downstream direction of paper feeding. Since it is characterized by a pressure contact load, unlike the bottom plate push-up method used in conventional paper feeding devices, the pressure load fluctuates depending on the amount of sheets stacked, causing paper feeding failures. has been resolved. In other words, the lever member in the paper feeding device of the present invention presses the sheet with its own weight in the paper feeding direction and has a trail sliding contact type, so that even if the stack amount of sheets changes, the document pressing load remains constant. ing. This allows all stacked sheets to be stably fed. At the same time, this lever member serves as a guide plate when inserting a sheet, and has the effect of preventing curled sheets from hitting the roller pressure contact portion and causing paper feeding defects such as folded edges and jams.

[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... Document conveyance device 101... Housing main body 102... Movable paper feeder 104... Fixed paper feed tray 200... Paper feed section 201... Movable guide plate 207... Solenoid 209...・Feeding lever (lever member) 210...
・First drive shaft 211...Second drive shaft 212...
- Feed roller (first paper feed roller) 213...Double feed prevention rollers 223, 227A, 228A...One-way roller 7
Chi226...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 swingable lever member is provided above the first paper feed roller and the second paper feed roller, and the weight of the lever member causes the first paper feed roller and the second paper feed roller to A paper feeding device characterized in that it is configured to press the outer peripheral surface of the paper feeding device. (2) The swinging rotation axis of the lever member is provided above in the upstream direction of paper feeding, and the sheet pressing position of the lever member is set to a predetermined pressure load near the pressure contact position of the double-feed prevention roller in the downstream direction of paper feeding. The paper feeding device according to claim 1, characterized in that it is configured as follows.