JPH0540236U - Sheet feeding device - Google Patents

Abstract

(57) [Abstract] [Purpose] When a sheet is pulled out from the separating / feeding unit by a conveying unit such as a pair of registration rollers, a sheet following the sheet is not conveyed from the separating / feeding unit and does not have a double feed. Getting a feeder. [Structure] The feeding rotating body is rotated in the conveying direction by the pulling force when the rear portion of the sheet is pulled out from the separating feeding means by the conveying means, and this rotation causes the separating rotating body to rotate in the direction opposite to the sheet conveying direction. The rotating force transmitting means is provided between the feeding rotating body and the separating rotating body.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is, for example, a separating rotary member for feeding a sheet and a separating rotating member for reversely feeding the second and subsequent sheets to the upstream side while making rotational contact with the rotating rotary member, and a separating means for separating the separated sheets. The present invention relates to a sheet feeding apparatus in which a leading edge is nipped and a rear portion of a sheet is sandwiched by the separating means so as to set a sheet feeding timing, and a platen of an image processing apparatus such as a copying machine, an image reader, or a facsimile is provided. It is used for feeding documents to the document feeder and for feeding sheets for image formation.

[0002]

[Prior Art]

 The structure of a conventional sheet feeding apparatus is shown in FIG.

As shown in the figure, the sheet feeding device 1 includes a feeding roller 4 as a feeding rotator on the upstream side along a sheet feeding path 2 and a separation feeding roller 5 which is a separation rotator. The means 3 and the registration roller pair 6 which is provided on the downstream side of the feeding path 2 and includes a pair of rollers.

The feeding roller 4 of the separating / feeding means 3 rotates in the sheet feeding direction, and the separating belt 5 rotates in the sheet blocking direction.

Of the plurality of sheets sent along the sheet feeding path 2, only one sheet in contact with the feeding roller 4 is fed by the separating and feeding means 3, and the other sheets are fed to the separating belt 5. Therefore, it is pushed back to the upstream side.

The leading end of the separated sheet is abutted against the registration roller pair 6, and the operation of the separation feeding means 3 is stopped when a slightly curved shape, that is, a registration loop is drawn as shown in the figure. To do. It is well known that the feeding posture is properly corrected by drawing the loop.

Then, the registration roller pair 6 is started at the feeding timing, and the one sheet is fed. At this time, conventionally, the separating / feeding means 3 is in a non-driving state, and the separating belt does not rotate. However, the feeding roller 4 is internally provided with a one-way clutch so that the feeding roller 4 rotates together with the sheet pulled out by the pair of registration rollers 6. This is because when the feeding roller 4 is stopped from rotating together, the backward pulling force on the sheet pulled by the registration roller pair 6 becomes too strong and the sheet feeding posture is disturbed or the registration roller pair 6 is disturbed. This is because slippage occurred in the machine and feeding timing was wrong.

[0008]

[Problems to be solved by the device]

 However, since the separation belt 5 does not rotate at all while the sheet is pulled out, the second sheet near the contact point between the separation belt 5 and the feeding roller 4 is the one sheet (hereinafter referred to as the first sheet). There is a problem that so-called continuous feeding (or continuous feeding) is carried out along with the above sheet or the preceding sheet. (Note that although there is a term similar to continuous feed or carry-out, which is called double feed or double feed, in the present specification, the above-described event in which a sheet is dragged by another sheet and then fed is continuously fed. In view of the above problems, the present invention takes the above-mentioned problems into consideration, and conveys a plurality of sheets including the above-mentioned continuous feeding from the viewpoint of the entire apparatus. When the sheet is pulled out from the separating / feeding means by the above, the sheet following the sheet is not conveyed from the separating / feeding means, and an object is to obtain a sheet feeding device without double feed.

[0009]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention rotates the feeding rotating body in the conveying direction by the pulling force when the rear portion of the sheet is pulled out from the separating feeding means by the conveying means, and this rotation causes the separating rotating body to move to the sheet. Rotational force transmitting means for rotating in the opposite direction to the conveying direction is provided between the feeding rotating body and the separating rotating body.

[0010]

【Example】

 Next, as an embodiment to which the sheet feeding device of the present invention is applied, a document feeding device for feeding a document to an image forming apparatus such as a copying machine will be described.

<Structure> As shown in FIG. 1, the document feeding device 10 includes a document tray 11 on which a document is placed, and a sheet feeding section which separates and feeds the document from the document tray 11 into one sheet. 20, a conveyance unit 50 that receives and conveys the document from the paper feeding unit 20, stops on the platen P of the image forming apparatus C to receive the exposure process, and a paper ejection unit 60 that ejects the exposed document. And a discharge tray 12 for accumulating discharged documents and a control device (not shown).

The sheet feeding apparatus of the present invention is applied to the sheet feeding unit 20, and hereinafter, the sheet feeding apparatus will be described as the sheet feeding unit 20.

The paper feed unit 20, the transport unit 50, and the paper discharge unit 60 are configured to be driven by the first drive motor M1, and the paper discharge unit 60 is separately driven by the second drive motor M2. ing.

The first drive motor M1 drives the non-circular half-moon roller 22 and the feeding rotating body such as the feeding roller 24 which are feeding means at the time of forward rotation, and drives the registration roller 29 and the conveying section 50 by reverse rotation. Is.

As shown in FIG. 1, the paper feed unit 20 is provided with a paper feed path 21 having guides 21 a and 21 b that extend to the entrance of the conveyance unit 50 and guide the document, following the downstream end of the document tray 11. ing. A half-moon roller 22 as a feeding means is provided below the uppermost stream side of the paper feed path 21.

The half-moon roller 22 comes into contact with the lowest document of the document on the document tray 11 and tries to feed it out. At the home position (HP), the cutout portion faces upward and the paper feed path 21 Have been evacuated from.

A stopper 23 is provided between the half-moon rollers 22 so as to pass through the guide 21 a and be retractable.

Next, a feeding roller 24, which is a feeding rotator, is provided on the downstream side along the sheet feeding path 21.

Further, above the feeding roller 24, there is provided a separation rotating body 25 composed of a pair of rollers 26 and 27 and a separation belt 28 stretched around the pair of rollers 26 and 27. Has been. The rollers 26 and 27 are fixed to shafts 26a and 27a, respectively, of which the shaft 26a is a drive shaft and acts to push back all but the lowest document to the upstream side.

Note that the feeding roller 24, which is a feeding rotating body, and the separating rotating body 25 constitute a separating feeding unit.

An empty sensor ETS for detecting the presence or absence of a document is provided between the half-moon roller 22 and the separating rotary member 25.

The paper feed path 21 is curved, and the original is turned over to face the entrance of the conveyance unit 50. Conveying means such as registration rollers 29 and 30 for catching the leading edge of the document and adjusting the posture to adjust the sheet feeding timing are provided near the curved portion, and a registration sensor 31 for detecting the sheet feeding timing of the document to be fed. Are arranged.

The conveyance unit 50 has a pair of belt rollers 51 and 52 supported on the side plate of the document feeding apparatus 10, a conveyance belt 53 is stretched around the belt rollers 51 and 52, and a plurality of press rollers 54 are provided. It is configured by deploying.

The paper discharge unit 60 is provided with a paper discharge path 61 having guides 61 a and 61 b that are largely curved from the exit of the transport unit 50 and turn over the document by approximately 180 degrees. A pull-out roller 62, a pinch roller 62a, and a paper discharge sensor 63 are provided from a position close to the conveyance unit 50 along the paper discharge path 61, and paper discharge rollers 65a and 65b are provided near the discharge port 64. ing.

Next, a control device (not shown) receives signals from the empty sensor ETS, the registration sensor 42, the paper discharge sensor 63, and the like to perform a predetermined calculation, and outputs the calculation result and various commands from the image forming apparatus C. A CPU is provided for driving and controlling the drive motors M1, M2, etc. in a timely manner on the basis of signals, and transmitting the control results to the image forming apparatus C.

A drive system centering on the sheet feeding unit 20, particularly a drive system around the feed roller 24 and the separation rotator 25, which are feed rotators, will be described in detail with reference to FIG.

The drive system of the paper feeding unit 20 belongs to the system of the first drive motor M1 as shown in the figure, and the output of the motor M1 is coaxial with the output pulley 101 connected to the output shaft via the timing belt 102 and the pulley 103. Is transmitted to the gear 105.

The gear 105 is also transmitted to the gear 109 via the gears 106, 107 and 108. The gear 109 is coupled to the shaft 24a of the feeding roller 24 via a one-wake latch (hereinafter abbreviated as OW).

The gear 109 is also coupled to the shaft 22 a of the half moon roller 22 via an intermediate gear 110 via an OW.

On the other hand, the shaft 24a of the feeding roller 24 has a gear 112 fixed to the other end thereof, and the gear 112 has a shaft 26a of the roller 26 on the drive side of the separating rotary body 25 via an intermediate gear 113. Is meshed with the gear 114 which is connected to.

The gear 105 is coupled to the shaft 105a via an OW, and is coupled to the shaft 51a via a pulley 120, a timing belt 121, and a pulley 122 provided at the other end of the shaft 105a, and a belt roller. Power is transmitted to 51.

The gear 123, which is also coupled to the shaft 51 a, is linked with the gear 125 of the shaft 29 a of the registration roller 29 via an intermediate gear 124. The shaft 29a is provided with an electromagnetic clutch 126 for engaging and disengaging the shaft 29a and the gear 125 at appropriate times.

<Operation> Based on the above configuration, the operation of the embodiment will be described below.

When the power is turned on, it is checked by the home position sensor HPS whether or not the half-moon roller 22 has reached the initial position (home position HP). When the home position sensor HPS is ON, the drive motor M1 is stopped. Then, the initialization is completed.

After the initialization is executed, when the document is placed on the document tray 11, the empty sensor ETS is turned on and the preparation for feeding is completed.

When a paper feed signal is received from the image forming apparatus C side, the paper feed operation is started and the first drive motor M1 is normally rotated.

The forward rotation of the motor M1 causes the half-moon roller 22 to feed out the lowermost document, which is fed by the feeding roller 24, and the separating belt 28 pushes back the second and subsequent sheets upward. Then, as shown in FIG. 2, the power is not transmitted to the registration roller 29 and the conveyance section 50 side by the OW of the shaft 105a during the above operation.

The sent-out original is detected by the registration sensor 31, the motor M1 stops after a short time, the leading edge of the original bites between the registration rollers 29 and 30 which are a pair of registration rollers, and a small amount of registration is performed at the rear. The registration operation is completed with the loop drawn.

After the minute time for completing the registration, the motor M1 is rotated in reverse. By this reverse rotation, power is transmitted to the belt roller 51 and the registration roller 29. On the other hand, due to the action of OW, the driving force is not transmitted to the half-moon roller 22, the separation roller 26, the feeding roller 24, etc., and these rollers remain stopped.

By the way, when the feeding roller 24 and the separating rotator 25 which constitute the separating feeding means are in a stopped state, they are formed when the document is fed by the rotation of the registration roller 29 as described above. When the registration loop is eliminated, this original document (preceding original document or first original document) is strongly pulled so as to rotate the feeding roller 24 in the feeding direction.

On the other hand, the number of originals delivered by the half-moon roller 22 and sent to the separating rotary member 25 is usually a plurality of sheets, and the originals are attempted to emerge downstream in connection with the preceding original extracting operation. ..

However, as shown in FIG. 2, the feeding roller 24 is released from the coupling with the drive motor side by the OW provided between the shaft 24a and the gear 109, and can smoothly rotate together. The rotation of the shaft 24a is directly transmitted to the shaft 26a via the gears 112, 113 and 114, and is transmitted from the roller 26 to the separation belt 28. In other words, the second and subsequent documents are always subjected to the separating action even during the pulling-out operation of the first document, and are not fed.

The original thus sent is localized at the reference position P1 of the platen P, and the image forming apparatus C executes the copying operation (exposure) here.

The processed document is again discharged from the platen P by the reverse rotation of the motor M1, and then discharged to the paper discharge tray 12 by the drive of the motor M2.

In the document feeding device 10, the motor M1 rotates in the normal direction due to the advance operation of the second document (second document) during the exposure operation, and the second document is fed during this period. It stands by ahead of the register roller 29.

<Effects of the Embodiment> According to this embodiment, the separating / feeding means including the feeding roller 24 for feeding the sheet and the separating / rotating body 25 for backward feeding the second and subsequent sheets to the upstream side, On the downstream side of the separating / feeding means, there are provided registration rollers 29 and 30 for nipping the leading end of the separated sheet to adjust the sheet feeding timing. When the registration rollers 29 and 30 are in operation, In a sheet feeding device in which the separation feeding means is not driven and the rear portion of the sheet is sandwiched by the separation feeding means and can be pulled out by the registration rollers 29 and 30, the operation of the registration rollers 29 and 30 causes the sheet When the end portion is pulled out from the separating and feeding means, the pulling force causes the feeding roller 24 to rotate in the feeding direction, and this rotation causes the separating rotary member to rotate. Since a rotational force transmitting means for rotating the sheet feeding device 25 in the reverse feeding direction is provided between the feeding roller 24 and the separating rotating body 25, when the feeding roller 24 rotates in association with the sheet pulling operation, the separating feeding means 24 The other sheet being sent to the place is pushed back to the upstream side by the separating rotary member 25, and the next sheet is taken along with the sheet being pulled out even if the driving of the separating and feeding means is stopped. Double feed can be prevented without being sent.

<Modification> The present invention is not limited to the above-mentioned embodiment, and the following modifications are possible, for example.

In the above-described embodiment, the sheet feeding device in which the registration of the leading edge of the sheet is corrected by the registration rollers 29 and 30 has been described. However, the sheet separated by the separating / feeding means is not subjected to the registration correction, and the conveying means is used. It may be a device that conveys by.

[0049]

[Effect of the device]

 According to the sheet feeding device of the present invention, a sheet feeding rotating body that is driven to rotate in the sheet conveying direction and sends out a contacting sheet, and a sheet feeding rotating body that is provided in contact with the sheet feeding rotating body and is opposite to the sheet conveying direction. The sheet fed and separated by this separating / feeding means, and the separating / feeding means having a separating / rotating body that obstructs the conveyance of the sheet following the sheet sent out by the feeding / rotating body. A sheet feeding device that conveys the sheet while pulling out the sheet from the sheet feeding means sandwiching the rear portion of the sheet while the driving of the sheet feeding means is stopped. The feeding rotating body is rotated in the conveying direction by the pulling force when the separating rotating means is pulled out, and this rotation causes the separating rotating body to move in a direction opposite to the sheet conveying direction. A rotational force transmitting means for rotating, the following effects are gills so provided between the feeding rotary member and said separating rotary member.

That is, when the rear portion of the sheet is pulled out from the separating / feeding means by the conveying means, when the feeding rotating body rotates due to the pulling-out operation, the rotational force is separated and rotated via the rotational force transmitting means. Since the separation rotator is transmitted to the body and rotates in the direction opposite to the sheet conveyance direction, the conveyance of the other sheets held in the separation feeding unit is blocked by the separation rotator, and the separation rotator and the separation rotator are separated. Even if the drive of the rotating body is stopped, the next sheet is not sent to the sheet that is being pulled out, and double feed can be prevented.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a document feeding device to which a sheet feeding device of the present invention is applied.

FIG. 2 is a power transmission system diagram centering on a paper feeding unit.

FIG. 3 is an explanatory view of a main part of a conventional sheet feeding device.

[Explanation of symbols]

 10 Document Feeding Device 20 Paper Feeding Unit (Sheet Feeding Device) 24 Feeding Roller (Feeding Rotating Body) (Separating Feeding Means) 24a Shaft (Power Transmission Means) 25 Separation Rotating Body (Separating Feeding Means) 28 Separation Belt (Separating Rotating Body) 29 Registration Roller (Registration Roller Pair) 30 Registration Roller (Registration Roller Pair) 112 Gear (Power Transmission Means) 113 Gear (Power Transmission Means) 114 Gear (Power Transmission Means) 26a Shaft (Power Transmission Means)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location // B65H 9/14 B 8922-3F

Claims (2)

[Scope of utility model registration request] 1. A feeding rotator that is driven to rotate in the sheet conveying direction and sends out a contacting sheet, and a feeding rotator that is provided in contact with the feeding rotator and is rotatably driven in a direction opposite to the sheet conveying direction. Separation and feeding means having a separation rotator that obstructs the conveyance of the sheet following the sheet sent out by the rotator, and the sheet separated and sent out by the separation and feeding means, in the drive stopped state of the separation and feeding means. A sheet feeding device having a conveying unit that conveys the sheet while pulling it out from the separating feeding unit that sandwiches the rear portion of the sheet, wherein the pulling force is used when the rear portion of the sheet is pulled out from the separating feeding unit by the conveying unit. Rotational force transmitting means for rotating the feeding rotating body in the conveying direction and rotating the separating rotating body in a direction opposite to the sheet conveying direction by this rotation is provided. A sheet feeding apparatus is characterized in that provided between the separating rotary member and the feed rotary member. 2. A registration roller that conveys the sheet while separating the sheet separated by the separating and feeding section to form a bend in the sheet and then pulling out the trailing edge of the sheet from the separating and feeding section. A sheet feeding device characterized by being a pair.