JPH0912196A - Paper feeding device - Google Patents

Abstract

PURPOSE: To make structure without using a magnetic clutch and also discharge paper sheet positively. CONSTITUTION: A body of a device is provided with a fixture end, and a free end is positioned downstream of a nip portion between a pressing roller 11 and a discharge roller 12 in sheet discharged direction. A thin film 20 as cantilever beam is so disposed that at least a part of its flexible portion covers the nip portion. When a driving source is reversely rotated to return a pickup roller 3 to its waiting position, a discharge roller 12 is also rotated reversely, so that entry of rear end of a document discharged into the nip portion is prevented by the thin film 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device for automatic feeding of paper such as originals, which is applied to a facsimile machine, a copying machine, an image scanner and the like.

[0002]

2. Description of the Related Art Conventionally, in a paper feeding device of a facsimile apparatus, when a document is set, a pickup roller that contacts the lowermost surface of the document and moves the document toward the document reading section, and a document located downstream of the pickup roller are provided. In general, a mechanism is provided that includes a separation / conveyance roller that separates the sheets one by one and conveys them to the document reading unit, and a discharge roller that discharges the document to the outside of the apparatus body. Further, conventionally, there is a configuration in which a driving unit for moving the pickup roller up and down is provided so that the pickup roller appears from the surface of the document placing table when the document is set, and an electromagnetic clutch is adopted as the driving unit. . However, the installation of the electromagnetic clutch leads to an increase in cost, and as a means for solving this problem, a technique disclosed in Japanese Patent Laid-Open No. 5-186071 has been conventionally disclosed. Next, the sheet feeding device described in that publication will be briefly described.

FIG. 18 is a block diagram showing an example of a conventional paper feeding device. 1 is a feed roller, 2 is a separation roller which is in contact with the feed roller 1, and 3 is a document set portion on a guide plate 4. 5 is a feed roller shaft that supports the feed roller 1 and the feed gear 6, 7 is a connecting gear that meshes with the feed gear 6 and the pickup gear 8 of the pickup roller 3, and 9 is a The pressure plate pressing down the original is shown.

No electromagnetic clutch is provided on the feed roller shaft 5, and drive transmission from a drive source such as a motor (not shown) is directly connected. The feed gear 6 provided on the feed roller shaft 5 has a built-in one-way clutch, and the one-way clutch causes the feed roller 1 to rotate when the rotary drive source rotates forward. At this time, both forward and reverse rotations of the rotary drive source are transmitted to the connecting gear 7, and the rotational force is transmitted to the pickup gear 8 via the connecting gear 7.

The pickup roller 3 is raised by the positive rotational force of the motor (clockwise rotation in FIG. 18) transmitted to the feed roller shaft 5, and the reverse rotational force of the motor (see FIG. 18).
It is configured to descend by rotating 18 counterclockwise).

Reference numeral 10 in the drawing is a conveying roller for receiving the original conveyed by the feed roller 1 and conveying the original to an image reading unit (not shown), 11 is a driven roller in contact with the conveying roller 10, and 12 is a driven roller. A discharge roller for discharging the document after the image has been read to the outside, and 13 a pressure roller in contact with the discharge roller 12. Transport roller 10, discharge roller
The drive motor 12 is the same motor (not shown) as the feed roller 1 and the pickup roller 3.

FIG. 19 is a perspective view showing a structure around a conventional discharge roller. Reference numeral 14 is a rotary shaft that pivotally supports the discharge roller 12, and 15 is a rotary shaft of the discharge roller 12 and both sides of the discharge roller 12. A wing-shaped kicking member made of chloroprene rubber, 16 is a slide bearing that rotatably supports one end of the rotating shaft 14, 17 is an upper guide plate, and 18 is an upper guide plate 16 located on both sides of the pressure roller 13. 2 shows a static elimination brush attached to the outer surface of the.

[0008]

With the configuration described above,
By rotating the drive source forward at the start of paper feeding,
The pickup roller 3 moves up, and by rotating the drive source in the reverse direction, the pickup roller 3 moves down and returns to the standby position.

Conventionally, a nip portion where the surfaces of the discharge roller 12 and the pressure roller 13 are in contact with each other (hereinafter, simply referred to as a nip portion means a nip portion between the discharge roller 12 and the pressure roller 13). As shown in FIG. 19, on the rotating shaft 14 of the discharge roller 12 and on both sides of the discharge roller 12, a plurality of sheets longer than the radius of the discharge roller 12 should be provided so that the trailing edge of the original does not remain in the vicinity. A kick-off member 15 composed of a wing was provided, and the rear end of the document left in the vicinity of the nip portion was pushed out onto a document tray (not shown) by rotating together with the discharge roller 12.

However, according to the above-described paper feeding device, in order to return the pickup roller 3 to the standby position,
The operation of rotating the drive source in the reverse direction is required, and the reverse rotation of the drive source also leads to the reverse rotation of the discharge roller 12 and the kicking member 15. Therefore, the discharge roller 12
When the original is curled, the kick-off member 15 reversely rotates, so that the kick-off member 15 scoops up the trailing end of the ejected document, and the trailing end of the document reenters the nip portion. There was a problem that the manuscript was damaged in the worst case.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, and to provide a sheet feeding device which does not use an electromagnetic clutch and is capable of reliably feeding and discharging sheets. To do.

[0012]

In order to solve the above-mentioned problems, the present invention provides a feed roller for contacting a separation roller to separate and convey a sheet into the apparatus main body, the separation roller and the feed roller. A pickup roller for feeding a sheet of paper between them, a discharge roller for coming into contact with a pressure roller and discharging the sheet that has passed through the inside of the apparatus main body, the pickup roller, the feed roller and the discharge roller. A drive source for driving, a drive means for moving the pickup roller up and down with respect to a paper feedable position in accordance with forward / reverse rotation of the drive source, and a free end when the fixed end is attached to the apparatus body. It is positioned so as to hang down to a position downstream of the straight line including the line of the contact portion between the pressure roller and the discharge roller in the paper discharge direction and beyond the contact portion, Characterized by providing a flexible member for suppressing intrusion into the contact portion of the rear end.

Further, the length of the flexible member in the axial direction of the discharge roller is defined as the length of the contact portion between the pressure roller and the discharge roller, and the contact portion between the pressure roller and the discharge roller is defined. And the flexible members are opposed to each other.

Further, the flexible member is provided outside the contact area between the pressure roller and the discharge roller and on both sides of the contact area.

Further, the flexible member is provided so that the discharge roller or the pressure roller and the flexible member are in a positional relationship of overlapping each other when the discharge roller is viewed in the axial direction.

When the length from the fixed end of the flexible member to the document discharged from the contact portion is represented by d and the thickness of the flexible member is represented by t, 50 ≦ d / t It is characterized in that the relationship of ≦ 200 is satisfied.

Further, the flexible member is characterized in that a plurality of free ends extend in a comb shape from one fixed end.

Further, the apparatus main body is provided with a static eliminating member whose front end is brought into contact with the surface of the discharged original. The static eliminating member has flexibility, and when the fixed end of the static eliminating member is attached to the main body of the apparatus, it is free end. Is positioned downstream of the straight line including the line of the contact portion between the pressure roller and the discharge roller in the paper discharge direction and within the range of the paper width, and the tip position of the free end of the static elimination member is Characterized by matching the free end of the flexible member.

[0019]

According to the above construction, the flexible member prevents the trailing edge of the discharged sheet from entering the contact portion between the pressure roller and the discharge roller. Therefore, when the rotation direction of the drive source is reversed, it is possible to prevent the paper from being caught in the contact portion between the pressure roller and the discharge roller and causing a jam.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION In order to better understand the present invention, modes of embodiments for solving the problems, that is, embodiments will be described in detail with reference to the drawings. Members corresponding to the members described in FIG. 18 or FIG. 19 are designated by the same reference numerals, and detailed description thereof is omitted.

FIG. 1 is a block diagram showing the inside of a facsimile apparatus equipped with the first embodiment of the present invention, in which 19 is a cover and 20 is a cover.
Indicates a flexible thin film made of PET.

A housing is constituted by the upper guide plate 17 and the cover 19, and a separating roller 2 and a driven roller 1 are provided inside the housing.
The upper unit is configured by disposing the pressure roller 13 and the like. At this time, part of the separation roller 2, the driven roller 11, and the pressure roller 13 is exposed from the upper guide plate 17.
Further, a charge eliminating brush 18 and a thin film 20 are provided on the downstream side of the pressure roller 13 in the upper unit in the document conveying direction.

As shown in FIG. 2, the thin film 20 has a length L corresponding to the maximum document passing width, and a nip where the surfaces of the discharge roller 12 and the pressure roller 13, which are the contact portions, come into contact with each other. The thin film 20 has a width W that covers the portion and one end of the thin film 20 in the width direction is fixed above the nip portion. That is,
The thin film 20 is swingably attached to the upper unit with its one end serving as a fixed end and the other end serving as a free end. In addition,
When the thickness of the thin film 20 is t (see FIG. 4) and the distance from the fixed end to the document position is d (see FIG. 4), 50 ≦ d / t
The thickness t is determined within a range that satisfies the expression ≦ 200.
In this embodiment, the thickness t is set to 75 μm.

FIG. 3 is a perspective view showing the outer appearance of the upper unit and the lower unit. Reference numeral 21 is an image reading portion, and 22 is a lower guide plate. As shown in FIG. 3, in the central portion of the lower unit, a pickup roller 3, a feed roller 1, a conveyance roller 10, an image reading unit 21, and a discharge roller are arranged in this order in the document conveyance direction.
12 are provided, and lower guide plates 22 are provided on both sides of the pickup roller 3, the feed roller 1, and the transport roller 10. Further, the upper unit is pivotally supported near the both ends of the discharge roller 12 with respect to the lower unit. When the upper unit is set to the lower unit, the separation roller 2 contacts the feed roller 1 and the pressure roller 13 contacts the discharge roller 12, as shown in FIG.

Next, the document feeding operation will be described.

FIG. 4 is an explanatory view showing the basic constitution of the first embodiment of the present invention, and FIG. 5 is a timing chart showing the document feeding operation. The stepping motor in FIG. 5 is a pickup roller 3, a feed roller 1, The sensor S1 is a drive source for the transport roller 10 and the discharge roller 12, the sensor S1 detects a document passing between the pickup roller 3 and the feed roller 1, and the sensor S2 is an image reading unit 21 and the transport roller.
A document passing between 10 and 10 is detected. In addition, the stepping motor is STD mode, DTL mode, SSF
It is possible to switch to three kinds of rotation speeds of modes.

First, when a document is placed on the main body of the apparatus, the sensor S1 detects the document and turns on, and a display panel (not shown) indicates that the document is set. Next, when the start button is pressed, the stepping motor starts driving in the STD mode, the pickup roller 3 moves up to the position shown by the broken line in FIG. 4, and the document passes through the nip portion between the feed roller 1 and the separation roller 2, The tip is detected by the sensor S2 and is turned on. After that, the image reading unit 21 is timed so that the leading edge of the document reaches the image reading unit 21.
Turn on to start image reading. Then, after the trailing edge of the original has passed the sensor S2 and turned off, the image reading section 21 is turned off at the timing when the trailing edge of the original reaches the image reading section 21, and image reading is stopped. Let Further, the image reading is stopped, and at the same time, the rotation of the stepping motor is switched to the DTL mode to convey the trailing edge of the document to the stamping position of the stamp. At this time,
If the leading edge of the next document has passed the sensor S2,
2 is on.

Then, the stepping motor is turned on in the STD mode to eject the previous document and turn on the image reading unit 21 at a timing when the leading edge of the next document reaches the image reading unit 21. Scan the original document. While the document is being read, the trailing edge of the document passes the sensor S1, but since there is no next document, the sensor S
1 is off. Further, when the trailing edge of the original passes the sensor S2, the sensor S2 is turned off. The image reading section 21 is turned off at the timing when the trailing edge of the original reaches the image reading section 21, and the image reading is stopped. Further, the image reading is stopped, and at the same time, the rotation of the stepping motor is switched to the DTL mode to convey the trailing edge of the document to the stamp position of the stamp, and after stamping, the stepping motor is rotated in the DTL mode to discharge the document.

After that, by further rotating the stepping motor in the reverse direction, the pickup roller 3 moves downward, disappears from the surface of the lower guide plate 22, and returns to the standby position as shown by the solid line in FIG. In this way, a series of document reading operations is completed.

With this configuration, when the stepping motor is rotated in the reverse direction to return the pickup roller 3 to the standby position, the discharge roller 12 also rotates in the reverse direction, but at this time, the discharge roller 12 tries to enter the nip portion. Since the trailing edge of the already ejected original comes into contact with the thin film 20 and the original is prevented from entering, the occurrence of jam at the nip portion is suppressed.

According to the first embodiment, the thin film
Although 20 has the maximum document width, as shown in FIG. 6, the same effect can be obtained even if the length is enough to cover the nip portion. Further, in this case, the film member can be saved.

FIG. 7 is a plan view showing the shape of the thin film in the second embodiment of the present invention, and 23 shows the thin film. In the second embodiment, a thin film 23 shown in FIG. 7 is provided instead of the thin film 20 shown in FIG. The thin film 23 is made of a PET material like the thin film 20 shown in FIG.
(See FIG. 1) A comb-shaped member having a plurality of flexible portions each having a length of (see FIG. 1) and a plurality of free ends extending from one fixed end. When the thin film 23 is attached to the upper unit, the nip portion is covered with the plurality of flexible portions.

By virtue of such construction, in the first embodiment, the thin film 20 is rotated when the stepping motor is rotated in reverse.
When a part of the sheet enters the nip portion, the entire flexible portion of the thin film 20 enters the nip portion, and there is no function to prevent the trailing edge of the original after discharge from entering the nip portion. However, in the second embodiment, since the thin film 23 has a plurality of free ends, even if a part of the thin film 23 enters the nip part, the other flexible part prevents the trailing end of the document from entering the nip part. To achieve higher reliability.

By the way, FIG. 8 is an explanatory view showing a state before the original passes through the static elimination brush and the thin film, and FIG.
FIG. 10 is an explanatory view showing a conveyance state of a stiff original in the configuration of the first embodiment, and FIG.
FIG. 6 is an explanatory diagram showing a conveyance state of a stiff original, that is, a thin original. As can be seen by comparing FIGS. 9 and 10, when the original is stiff, the thin film 20 is largely bent, and the original surface is brought into contact with the static elimination brush 18 and conveyed. On the other hand, in the case of a thin original, the thin film 20 does not bend or has little bending, and is pushed downward by the thin film 20.
As shown in 10, the original surface may be conveyed without contacting the static elimination brush 18. In that case, the static electricity generated by passing the paper cannot be removed, and the static electricity sticks to the original that has been ejected, and as shown in FIG. 11, the original breaks in the middle, causing a stack defect, It may cause document ejection failure. The following third embodiment is made in view of such a point. In addition,
Reference numeral 24 denotes a document tray on which the discharged documents are placed.

FIG. 12 is a plan view showing the structures of a thin film and a charge eliminating brush according to the third embodiment of the present invention.
Shows a static elimination brush. This static elimination brush 25 is obtained by further lengthening the bristles of the static elimination brush 18 shown in FIG. 7 and extending its free end to a position equal to the position of the free end of the thin film 23. is there. That is, in the third embodiment, in addition to the conventional structure shown in FIG. 18, the thin film 23 shown in FIG. 7 is provided, and the static elimination brush 25 is provided between the thin film 23 and the upper unit. .

With this structure, since the static elimination brush 25 contacts the original regardless of the waist of the original, it is possible to eliminate the static electricity generated by the passing of the original, and it is possible to eliminate the trouble related thereto. it can.

Next, a fourth embodiment will be described.

With the configuration of the first embodiment described above, it is possible to prevent the occurrence of jam in the nip portion due to the reverse rotation of the stepping motor when returning the pickup roller 3 to the standby state.

However, even if the thin film 20 is provided on the downstream side of the discharge roller 12, if it is provided at a position away from the nip portion, when the stepping motor is rotated in the reverse direction, as shown in FIG. 20 and 12 eject rollers
It is meaningless because the trailing edge of the original easily enters the nip portion from A between On the other hand, if they are too close to each other, the thin film 20 will be sandwiched between the discharge roller 12 and the pressure roller 13 when the upper unit is opened halfway during the removal of the jammed original, the cleaning of the reading glass, the conveyance roller, etc. Rare,
It may break.

FIG. 15 is an explanatory view showing a process in which the thin film is broken when the upper unit is opened and closed.

FIG. 15A shows a normal state. When the upper unit is opened from this state, the upper unit rotates about the rotation center B with respect to the lower unit.
Also, as shown in FIG. 15B, the pressure roller 13 is separated from the discharge roller 12 and the free end of the thin film 20 is positioned on the discharge roller 12. When the upper unit is closed in this state, the leading edge of the thin film 20 is sandwiched between the discharge roller 12 and the pressure roller 13 as shown in FIG.
As a result, the tip of the thin film 20 is broken as shown in FIG. The fourth embodiment described below solves such a problem.

FIG. 16 is a perspective view showing the structure around the discharge roller of the fourth embodiment of the present invention, and FIG. 17 is a side view showing the structure of the main parts around the discharge roller of the fourth embodiment of the present invention. Indicates a thin film. In the fourth embodiment, a thin film 26 shown in FIG. 16 is provided instead of the thin film 20 shown in FIG. That is, the thin films 26, 26 are positioned on the sides of the kicking members 15, 15 attached to both sides of the discharge roller 12, respectively, and the free ends of the thin films 26, 26 are opposed to the rotary shaft 14 of the discharge roller 12. , Thin films 26, 26 are fixed to the upper unit. At this time, as shown in FIG. 17, when the discharge roller 12 is viewed from the side, the flexible portions of the thin film 26, 26 are located downstream of the nip portion in the document conveying direction and inside the radius of the discharge roller 12. doing.

With this structure, since the thin films 26, 26 do not face the nip portion between the discharge roller 12 and the pressure roller 13, the thin films 26, 26 are not discharged even when the upper unit is opened. As a result, the problem that the thin films 26, 26 are caught in the nip portion and broken is eliminated. Further, since the flexible portions of the thin films 26, 26 are located on the downstream side of the nip portion in the document conveying direction and inside the radius of the discharge roller 12, the thin film 26, 26 is placed between the discharge roller 12 and the thin films 26, 26. ,
Since there is no gap for the trailing edge of the discharged document to enter, it is possible to more reliably prevent the trailing edge of the document from entering the nip portion.

Regarding the shape of the thin film, the flexible portion of the thin film may be formed, for example, in a sawtooth shape in addition to the comb-teeth shape shown in this embodiment. Further, a charge eliminating cloth may be applied instead of the charge eliminating brush, and if the charge eliminating cloth has the same flexibility as the thin film, the charge eliminating cloth may also have the function of the thin film. It is possible.

[0045]

According to the present invention configured as described above, a flexible member is provided on the downstream side of the contact portion between the pressure roller and the discharge roller in the document conveying direction, so that the pickup roller is provided. When the drive source is rotated in the reverse direction to return the sheet to the standby position, the discharge roller also rotates in the reverse direction, but it is flexible that the trailing edge of the discharged document tries to enter the contact part between the pressure roller and the discharge roller. Since the elastic member suppresses, it is possible to prevent the occurrence of jam at the contact portion between the pressure roller and the discharge roller.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing the inside of a facsimile apparatus including a first embodiment of the present invention.

FIG. 2 is an explanatory view showing the shape of a thin film.

FIG. 3 is a plan view showing the outer appearance of a lower unit facing the upper unit.

FIG. 4 is an explanatory diagram showing the basic configuration of the first embodiment of the present invention.

FIG. 5 is a timing chart illustrating a document feeding operation.

FIG. 6 is an explanatory view showing another shape of the thin film.

FIG. 7 is a plan view showing the shape of a thin film according to the second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a state before a document passes through the static elimination brush and the thin film.

FIG. 9 is an explanatory diagram showing a conveyance state of a stiff original in the configuration of the first embodiment.

FIG. 10 is an explanatory diagram showing a conveyance state of a stiff original in the configuration of the first embodiment.

FIG. 11 is a diagram showing stacking defects when a flat document is conveyed in the configuration of the first embodiment.

FIG. 12 is a plan view showing the configurations of a thin film and a charge eliminating brush according to a third embodiment of the present invention.

FIG. 13 is an explanatory diagram showing a conveyance state of a stiff original document in the configuration of the third exemplary embodiment of the present invention.

FIG. 14 is a side view showing a configuration when a thin film is provided at a position apart from a nip portion.

FIG. 15 is an explanatory diagram showing a process in which the thin film is broken when the upper unit is opened and closed.

FIG. 16 is a perspective view showing a configuration around a discharge roller according to a fourth embodiment of the present invention.

FIG. 17 is a side view of the main part of FIG.

FIG. 18 is a configuration diagram showing an example of a conventional paper feeding device.

FIG. 19 is a perspective view showing a configuration around a conventional discharge roller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Feed roller, 2 ... Separation roller, 3 ... Pickup roller, 4 ... Guide plate, 5 ... Feed roller shaft, 6 ... Feed gear, 7 ... Connection gear, 8 ... Pickup gear, 9 ... Pressure plate, 10 ... Conveyor roller , 11
... driven roller, 12 ... discharge roller, 13 ... pressure roller,
14 ... Rotary shaft, 15 ... Kicking-off member, 16 ... Slide bearing, 17 ... Upper guide plate, 18, 25 ... Eliminating brush, 19
… Cover, 20, 23, 26… Thin film, 21… Image reading part, 22… Lower guide plate, 24… Original tray.

Claims (7)

[Claims] 1. A feed roller for contacting a separation roller to separate and convey a sheet into an apparatus main body, a pickup roller for feeding a sheet between the separation roller and the feed roller, and a pressure roller. And a drive source for driving the pickup roller, the feed roller, and the discharge roller, and a forward / reverse rotation of the drive source. Driving means for moving the pickup roller up and down with respect to the paper feedable position, and when the fixed end is attached to the apparatus body, the free end is more straight than the straight line including the line of the contact portion of the pressure roller and the discharge roller. On the downstream side of the paper discharge direction,
And a flexible member that is positioned so as to hang down beyond the contact portion and that prevents the trailing edge of the sheet from entering the contact portion. 2. The length of the flexible member in the axial direction of the discharge roller is defined as the length of the contact portion between the pressure roller and the discharge roller, and the contact portion between the pressure roller and the discharge roller is set. 2. The paper feeding device according to claim 1, wherein the flexible members face each other. 3. The sheet feeding device according to claim 1, wherein the flexible member is provided outside the contact area between the pressure roller and the discharge roller and on both sides of the contact area. 4. The flexible member is provided so that the discharge roller or the pressure roller and the flexible member are in a positional relationship of overlapping with each other when the discharge roller is viewed in the axial direction. 3. The sheet feeding device described in 3. 5. When the length from the fixed end of the flexible member to the document discharged from the contact portion is d and the thickness of the flexible member is t, 50 ≦ d / t The sheet feeding device according to claim 1, 2, 3, or 4, wherein the relationship of ≤200 is satisfied. 6. The flexible member according to claim 1, 2, 3, or 4, wherein a plurality of free ends extend in a comb-like shape from one fixed end. Paper feeder. 7. A static eliminating member whose tip portion abuts on the surface of the discharged original is provided in the apparatus main body, and the static eliminating member has flexibility, and when the fixed end of the static eliminating member is attached to the main body of the apparatus,
The free end is positioned downstream of the straight line including the line of the contact portion between the pressure roller and the discharge roller in the paper discharge direction and within the range of the paper width, and the tip position of the free end of the static elimination member is 7. The paper feeding device according to claim 1, 2, 3, 4, or 6, wherein the paper feed device coincides with a free end of the flexible member.