JP2002087627A - Paper feeder - Google Patents

Abstract

(57) [Problem] To provide a mechanism for automatically separating a sheet in a process of guiding the sheet to a sheet feeding position of a sheet feeding roller, and to reliably prevent a double feed of the sheet. Provide equipment. When a sheet is fed to a sheet feeding position of a sheet feeding roller, a leading end of the sheet is slid along a separating member provided on a support member. Adsorption between sheets of paper is eliminated. The sheet 15 separated by the separation member 11 is prevented from being double fed by the separation member 3 in that state, and is fed and conveyed by the sheet feeding roller 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device used in an image forming apparatus such as a printer, a facsimile, a copying machine, and the like.

[0002]

2. Description of the Related Art Conventionally, in a paper feeder used in an image forming apparatus such as a printer, a facsimile, a copying machine or the like, a separating member made of a high friction material such as polyurethane foam or rubber is provided on a paper feed roller by compression. There is also known a device provided with a sheet double feed prevention mechanism for separating the sheets sent in an overlapping manner at the nip portion.

[0003]

In general, when feeding paper, the influence of moisture, static electricity, and the like, especially when the paper is cut and stacked, when the paper is added, or when the paper is placed, For example, when the sheet bundle is not sufficiently separated, three or more sheets or more than ten or more sheets may be fed together due to the friction coefficient between sheets or the attraction between sheets.

However, when the two sheets advance between the paper feed roller and the separating member, the sheet double-feeding mechanism separates the sheets on the lower surface by the frictional force of the separating member to prevent double feeding. However, when three or more sheets have entered, only one of the sheets cannot be separated.

More specifically, when three or more sheets enter between the sheet feeding roller and the separating member at the same time, the lowermost sheet thereof comes into contact with the separating member, so that the sheet is prevented by the frictional force of the separating member. However, paper that does not contact the separation member above the lowermost portion is fed by the conveyance force of the paper feed roller without being subjected to the frictional action of the separation member and cannot be prevented from being double-fed. It is.

Further, in order to avoid the above-mentioned double feeding, the user sorts the paper in advance and then sets the paper on the sheet mounting table. However, in this method, when the paper cannot be sufficiently separated. In some cases, they may forget to handle them, and it is not a fundamental problem solution. Further, even if the user does not forget to separate the paper, it is necessary to perform the work of separating the paper every time the paper is set, which causes a problem that it takes much time and effort.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mechanism for automatically separating sheets in a process of guiding the sheets to a sheet feeding position of a sheet feeding roller in order to prevent the sheets from being double fed. It is an object of the present invention to provide a sheet feeding device capable of preventing the above problem.

[0008]

The present invention has the following arrangement.

(1) a paper feed roller for feeding and conveying paper;
A paper loading table that approaches or separates from the paper feed roller while holding the leading end of the paper to be stacked, and the paper loading table approaches the paper feed roller to feed the paper to the paper feed roller. In the paper feeding device for guiding to the paper feeding position, a separating member is provided for separating the leading end of the paper stacked on the paper mounting base when the paper mounting base approaches or separates from each other.

In this configuration, when the paper mounting table approaches and separates from the paper feed roller, the leading end of the paper stacked on the paper mounting table is separated by the separation member. The separating member slides along the leading end of each of the stacked sheets, and separates a plurality of sheets of paper that are attracted to each other.

(2) The separating member is provided on a surface of the supporting member provided with a separating member which presses against the paper feed roller to prevent double feeding of the paper and which comes into contact with the paper.

In this configuration, when the sheet is guided to the sheet feeding position of the sheet feeding roller, the sheet first moves while being slid by the separating member, so that the sheets are not attracted to each other. Passes through the nip between the separating member and the sheet feeding roller, the separating member surely performs the separating operation.

(3) The paper feeder includes a push-up lever for bringing the paper mounting table closer to the paper feed roller, and an elastic body for urging the support member in a direction of contact with the paper feed roller. In a reciprocating operation of the support member between a standby position in a state of non-contact with the roller and a sheet feeding position in a state of being in contact with the sheet feeding roller using the urging force of the elastic body,
The movement of the support member from the sheet feeding position to the standby position is performed by an operation in a direction opposite to the direction of the push-up operation after the push-up lever pushes up the sheet mounting table.

In this configuration, the push-up lever, which pushes up the paper mounting table, engages with the support member when lowering the paper mounting table so that the paper is disposed at the paper feeding position of the paper feeding roller. The support member is separated from the paper feed roller, and the support member and the paper feed roller are stopped as they are in a non-contact state. When the engagement between the support member and the push-up lever is released, the support member is kept in contact with the paper feed roller by the urging force of the elastic body.

(4) The support member is provided with an engaging portion, and a stop portion for stopping the support member at a predetermined sheet feeding position by engaging with the locking portion is provided.

In this configuration, the support member presses the paper feed roller by the urging force of the elastic body. By providing the stopping portion, the supporting member engaged with the stopping portion is provided. The position of the member is determined, and the strength with which the support member presses the paper feed roller is adjusted according to the position.

[0017]

FIG. 1 shows the configuration of an ink jet printer to which a paper feeder according to the present invention is applied. The paper feed device of this ink jet printer is provided with a paper feed roller 1 that rotates at a constant peripheral speed to feed and convey paper. In the vicinity of the paper feed roller 1, a paper mounting table 2 on which the paper 15 is loaded is supported by a fulcrum 16, and the paper mounting table 2 is swingable around a fulcrum 16 within a predetermined range. The rotation operation is performed on the sheet table 2.
This is performed by the action of the push-up lever 9 provided below. That is, the push-up lever 9 is rotatable about one end, and abuts on the bottom surface of the sheet mounting table 2 at the other end. By pushing up the push-up lever 9, the paper placing table 2 approaches the paper feed roller 1, and the leading end of the paper 15 stacked on the paper placing table 2 is guided to the paper feed position of the paper feed roller 1.

As a result, the upper surface of the stacked paper 15 comes into pressure contact with the paper feed roller 1, and only the uppermost paper is fed to the paper feed roller 1. In addition, when the push-up lever 9 rotates in the counterclockwise direction, the sheet mounting table 2 is separated from the sheet feed roller with the operation of the push-up lever 9.

On the other hand, below the paper feed roller 1,
A support member 10 is provided on the paper supply side so as to be able to approach and separate from the paper supply roller 1. A separating member 3 for preventing double feeding of sheets is provided on the upper part of the supporting member 10. A separating member 11 for separating is provided.

A spring 1 for urging the support member 10 in the direction of the paper feed roller 1 is provided below the support member 10.
2a is provided.

The separating member 3 is made of a high friction material such as foamed polyurethane or foamed rubber, is rotatably supported, and is provided so as to be pressed against the paper feed roller 1 with a predetermined pressing force by a spring 12b. Have been.

The separating member 11 is formed of a sheet material made of a foaming material, an elastic body such as rubber, a nonwoven fabric such as suede, cork, or a flocked brush. And adhered to the surface of the support member 10 that comes into contact with the paper 15.

Referring now to FIG. 5, the positional relationship between the separating member 11 and the paper 15 is shown. FIG. 5 is a view of the sheet mounting table 2 as viewed from above.
5 is flush with the surface of the leading edge defining plate 21 that defines the position of the leading edge of the sheet to be stored, or is slightly closer to the sheet 15 than the surface of the leading edge defining plate 21. It is attached in a state of protruding.

In this configuration, a series of operations of the ink jet printer to which the paper feeding device of the present invention is applied will be described. The loaded paper slides along the separation member 11 while the paper feeding roller 1 feeds the paper. To the paper feed roller 1
Double feed is prevented in the nip portion constituted by the and the separating member 3.

FIG. 6 shows the nip portion. FIG. 6 is a side view of the sheet feeding device of the present invention. In FIG. 6, the nip portion is a portion where the sheet feeding roller 1 and the separating member 3 are in contact with each other.

One sheet of paper 15 that has passed through the nip is
The paper is conveyed by a pinch roller 4 and a guide roller 5 that rotate while being in contact with the paper feed roller 1,
Led to. The printing unit 6 includes a platen that supports the paper and a print head that is provided so as to be able to reciprocate in the longitudinal direction of the platen. The printing unit 6 is controlled by a print signal and prints on the surface of the paper 15 that is sent onto the platen. I do.
The printed paper 15 is discharged to the discharge tray 8 by the discharge roller 7.

Next, the operation of each member constituting the sheet feeding device of the present invention will be described.

As shown in FIG. 2, the paper mounting table 2 is rotatably supported on a fulcrum 16 as a central axis, and paper 15 before printing is loaded and stored on its upper surface.

As described above, a push-up lever 9 for pushing up the sheet placing table 2 is rotatably provided below the sheet placing table 2. The operation of the push-up lever 9 is roughly controlled based on a paper feed signal from the inkjet printer main body, and is rotated clockwise by the paper feed signal to push the paper mounting table 2 in a direction approaching the paper feed roller. The uppermost sheet 15 loaded on the sheet mounting table 2 is pressed against the sheet feeding roller 1, and when the sheet feeding is completed, the sheet is rotated counterclockwise by a release signal from the ink jet printer main body, and The mounting table 2 is controlled to return to the original position.

Here, the operation of the push-up lever 9 will be described in detail with reference to FIG. First, a link member 17a is provided at the end of the push-up lever 9 as shown in FIG.
The link member 17a is pin-connected to the link member 17b, and the link member 17b is pin-connected to the link member 17c. The rotation from the gear 18 is directly transmitted to the link member 17c, and a driving force from a motor is transmitted to the gear 18 although not shown in the drawing. By the crank mechanism constituted by the link members 17a to 17c, the push-up lever 9 makes one reciprocation within a predetermined rotation range around the fulcrum 16 while the gear 18 makes one rotation.

A paper feed signal from the main body of the ink jet printer is first transmitted to a motor, which operates, and the push-up lever 9 operates via a crank mechanism.

Here, the push-up lever 9 must be stopped in a state where the paper 15 on the paper mounting table 2 comes to the paper feed position of the paper feed roller 1, and against the restoring force of the spring 12a. Since the support member 10 must be stopped at the standby position described later, it is necessary to prevent the gear 8 from rotating in the reverse direction.

The reverse rotation is prevented by a ratchet mechanism including a cam 19 and a ratchet claw 20. With this mechanism, the gear 18 can rotate in the counterclockwise direction in FIG. 1, but cannot rotate in the counterclockwise direction. With the above configuration, the operation of the push-up lever 9 is controlled.

That is, the state in which the push-up plate 9 pushes up the paper table 2 and the push-up plate 9
Since the gear 18 is fixed in a state where the supporting member 10 is pushed down, the state of the push-up lever 9 is maintained even when the driving of the motor is stopped.

Next, the interlocking operation of the push-up lever 9, the sheet mounting table 2, and the support member 10 will be described with reference to FIG. Here, the support member 10 is provided with an engagement portion 13, and the engagement portion 13 engages with the tip of the push-up lever 9. A spring 12a is provided below the support member 10 to urge the support member 10 in the direction of the paper feed roller 1.
Is provided.

For this reason, the supporting member 10 is
When no force opposing the elastic force a is applied, the sheet feeding roller 1 and the separating member 3 are urged in a contacting direction. Here, the position of the support member 10 in contact with the paper feed roller 1 is referred to as a paper feed position. Conversely, a position where the support member 10 is placed in a non-contact state with the paper feed roller by the push-up lever is referred to as a standby position.

FIG. 4A shows a state (standby state) of the sheet feeding apparatus of the present invention before sheet feeding. The paper feed roller 1 is rotating at a constant peripheral speed in the direction of the arrow in the figure, and the push-up lever 9 is configured such that the tip of the push-up lever 9 is engaged with an engaging portion 13 provided on the support member 10. By the engagement, the support member 10 is stopped at the standby position against the elastic force of the spring 12.

When a paper feed signal is sent to the paper feeder in the standby state described above, the push-up lever rotates in the direction of the arrow as shown in FIG. The rotation of the push-up lever 9 pushes up the sheet table 2 on which the sheet 15 is placed. Accordingly, the support member 10 includes the spring 12a.
Due to the urging force, the push-up lever 9 moves upward following the movement of the distal end.

Then, as shown in FIG. 4C, the push-up lever 9 is rotated to some extent, and the engaging portion 13 of the support member 10 is rotated.
When the engagement between the lever and the lifting lever 9 is released, the spring 1
The separating member 3 provided on the upper portion of the support member 10 by the urging force of 2a abuts on the paper feed roller 1, and the engaging portion 13 formed on the support member 10 is provided as a stopping portion on the ink jet printer main body. The support member 10 is prevented from moving upward by the engagement.

Therefore, the separating member 3 is pressed against the sheet feeding roller 1 with a predetermined pressing force, and the supporting member 10 is placed in a state where the upward movement is restricted. At this time, the strength of the pressing force of the separation member 3 against the paper feed roller 1 is determined by the position of the pin 14 as a stationary portion. In the present embodiment, the pin 14 is provided on the ink jet main body, but the pin 14 may be provided on the paper feeder side as long as the pin 14 can be engaged with the engaging portion 13 of the support member 10. is there.

In the present embodiment, the engaging portion 13 provided on the support member 10 is for holding the support member 10 at a predetermined standby position, and at the same time, the pin 14 provided on the main body. And also serves to stop the upward movement of the support member 10 at a predetermined position. In the present embodiment, the engaging portions 13 are also used, but they may be provided at different positions.

In the standby position, the engaging portion 13 formed on the support member 10 is locked by the push-up lever 9 so that the support member 10 can be held at the standby position. Is moved upwardly by the spring 12a.
Is locked to a pin 14 provided in the ink jet printer main body, so that the support member 10 (separation member 3) can be held at a predetermined position for sheet feeding. Is held so that the leading edge of the sheet and the separating member 11 appropriately contact each other.

Further, as shown in FIG. 4 (d), the rotation of the push-up lever 9 pushes up the paper mounting table 2, so that the leading edge of the paper 15 loaded on the paper mounting table 2 is It comes into contact with the separating member 11 provided on the front surface of the support member 10 placed in the stopped state, whereby the leading end of the stacked sheets 15 is reliably separated.

Next, when the uppermost stage of the sheet reaches a position where it comes into contact with the sheet feeding roller 1, the sheet subjected to the loosening process is fed by the rotating sheet feeding roller 1. The fed paper is sent to the nip between the paper feed roller 1 and the separating member 3.

At this time, since the leading end of the sheet 15 is separated by the separating member 11, three or more sheets as in the related art or ten or more sheets are collectively fed. Multiple feeds are prevented.

Also, even if two sheets are fed,
The separation member 3 prevents the paper on the lower surface from being conveyed,
It is prevented that both sheets are conveyed to the printing unit.

More specifically, since the position where the separation member 11 is provided and the position where the separation member 3 is provided are located on the same path along the sheet transport direction, the separation member 11 is provided.
By the synergistic effect that the part separated by the separation member receives the separating action of the separating member 3, a reliable separating effect can be obtained.

At this point, the top sheet is fed,
When the leading end of the sheet 15 is nipped by the nip between the sheet feeding roller 1 and the pinch roller 4, a release signal is output to the sheet feeding device.

As a result, the push-up lever 9 rotates counterclockwise, the sheet table 2 descends, and the push-up lever 9 is engaged with the engaging portion 13 formed on the support member 10. Even during the downward movement, the leading edge of the sheet 15 and the separating member 11 are in contact with each other due to the weight of the sheet, so that the separating process is performed. Further, the push-up lever 9 lowers the support member 10 against the elastic force of the spring 12a and stops the support member 10 at the standby position.

As described above, in this embodiment,
Since the push-up lever 9 moves the paper placing table 2 and the support member 10 toward and away from the paper feed roller 1, the paper feed roller 1
Can be constantly rotated. Accordingly, no special control is required, and the friction member constituting the separation member 3 is pressed against the paper feed roller 1 only during paper feeding, so that friction and deformation of the friction member can be prevented. Can be.
Further, since the sheets can be separated during the vertical movement of the sheet mounting table 2 and are surely separated before the sheet is fed, double feed of three or more sheets or more than ten sheets is prevented as in the related art. In both cases, the portion where the loosening process has been performed is subjected to the separating action by the separating member 3, so that double feeding can be reliably prevented.

[0051]

As described above, according to the present invention, (1) the paper feed roller for feeding and conveying the paper and the paper feed roller approaching or separating from the paper feed roller while holding the leading end of the stacked paper A paper mounting table, and wherein the paper mounting table approaches the paper feed roller to guide the paper to a paper feed position of the paper feed roller;
By providing a separating member for separating the leading end of the paper loaded on the paper loading table during the separating operation, the paper loading table is loaded on the paper loading table when the paper loading table approaches and separates from the paper feed roller. It is possible to separate the leading end of the sheet thus set by the separating member. While the separating member slides along the leading edge of each of the stacked sheets, the separating member separates the plurality of sheets adsorbed to each other, so that it is possible to save time and effort for pre-separating the sheets by the user. Since the separation operation by the separation member is performed more reliably, double feeding of sheets can be prevented.

(2) The separation member is provided on a surface of a support member provided with a separation member that presses against the paper feed roller and prevents double feeding of the paper, and is in contact with the paper.
When the paper is guided to the paper feed position of the paper feed roller, first, the paper moves while being slid by the separating member, so that it is possible to eliminate the attraction between the respective papers. Therefore, the separation operation can be reliably performed by the separation member.

(3) The support member is formed by a push-up lever for bringing the paper mounting table close to the paper feed roller and a spring for urging the support member in the direction of contact with the paper feed roller. In a reciprocating operation between a standby position in which the paper supply roller is not in contact with the paper supply position and a paper supply position in which the support member is in contact with the paper supply roller using the urging force of the spring. The movement of the support member from the sheet feeding position to the standby position is performed by the operation in the direction opposite to the direction of the push-up operation after the push-up lever pushes up the sheet mounting table, thereby feeding the sheet. A push-up lever that pushes up the paper mounting table so as to be disposed at the paper feeding position of the paper roller engages with a support member when lowering the paper mounting table to separate the support member from the paper supply roller, The support member and the paper feed roller are not It is restrained so as to keep the state of the touch. When the engagement of the support member with the push-up lever is released, the support member is kept in contact with the paper feed roller by the urging force of the spring.

Since the above series of operations are all performed by the operation of the push-up lever, no special control mechanism is required other than the control of the push-up lever, and the structure of the sheet feeding device becomes complicated. Can be prevented.

(4) The support member has an engagement portion, and a stop portion for stopping the support member at a predetermined sheet feeding position by engagement with the engagement portion is provided. Presses the paper feed roller by the urging force of the spring, but by providing the stopping portion, the position of the support member engaged with the stopping portion is determined, and the supporting position is determined by the position. The strength with which the member presses the paper feed roller can be adjusted.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating an operation of an ink jet printer to which a sheet feeding device of the present invention is applied.

FIG. 2 is a configuration diagram of a sheet feeding device of the present invention.

FIG. 3 is a diagram illustrating an operation of a push-up lever in the sheet feeding device of the present invention.

FIG. 4 is a diagram illustrating operations of a push-up lever and a support member in the sheet feeding device of the present invention.

FIG. 5 is a diagram showing an arrangement of a separating member in the sheet feeding device of the present invention.

FIG. 6 is a diagram illustrating a contact state between a sheet feeding roller and a separating member in the sheet feeding device of the present invention.

[Explanation of symbols]

 1-Sheet Roller 2-Paper Placement Table 3-Separation Member 4-Pinch Roller 5-Guide Roller 6-Printing Section 7-Discharge Roller 8-Discharge Tray 9-Push-Up Lever 10-Support Member 11-Separation Member 12 ( 12a-12b)-Spring 13-Engagement part 14-Pin 15-Paper 16-Support point 17-(17a-17c) Link member 18-Gear 19-Cam 20-Ratchet pawl 21-Tip edge defining plate

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F343 FA02 FB02 FB03 FB04 FC01 GA03 GB01 GC01 GD01 HB03 HC24 HD09 HD18 JA01 JD03 JD08 JD13 JD33 KA06 KB04 LA04 LA15 LB08 LC20 MC23

Claims (4)

[Claims] A paper feed roller for feeding and transporting the paper; and a paper mounting table that approaches or separates from the paper feed roller while holding the leading end of the stacked paper. In the sheet feeding device that guides the sheet to the sheet feeding position of the sheet feeding roller by approaching the sheet feeding roller, when the sheet placing table approaches or separates, the sheet loaded on the sheet placing table is A sheet feeding device provided with a separating member for separating a leading end. 2. The sheet separating member according to claim 1, wherein said separating member is provided on a surface of said supporting member provided with a separating member which presses against said sheet feeding roller to prevent double feeding of the sheet. 2. The paper feeding device according to 1. 3. A paper feed roller, comprising: a push-up lever for bringing the paper mounting table close to the paper feed roller; and an elastic body for urging the support member in a direction of contact with the paper feed roller. The reciprocating operation of the support member between a standby position in a state of non-contact with the sheet supply position and a sheet supply position in a state of being in contact with the sheet supply roller using the urging force of the elastic body. The moving of the member from the sheet feeding position to the standby position is performed by an operation of the push-up lever in a direction opposite to the push-up operation direction after pushing up the sheet mounting table. 3. The paper feeding device according to any one of 2. 4. The apparatus according to claim 1, wherein said support member has an engagement portion, and a stop portion for stopping said support member at a predetermined sheet feeding position by engagement with said locking portion is provided. The sheet feeding device according to any one of claims 1 to 3.