JP2001080806A - Sheet carrier and image forming device therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure guide of sheets depending on the toughness of sheets. SOLUTION: A sheet carrier has an elastic guide member 138b provided at a combined point of plural sheet carrying passages 55, 57, through which sheets are guided, so as to be tilting at its downstream end in a sheet carrying direction while leaving at least one sheet carrying passage and blocking the other sheet carrying passage, a bent piece 138be bent along the combined point and formed at the downstream end of the guide member, and a thrusting means 58 for thrusting the guide member at its middle to the sheet carrying passages, the thrusting means being position-adjustable to the sheet carrying direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sheet conveying apparatus for conveying a sheet, and an image forming apparatus including the sheet conveying apparatus, such as a copier, a facsimile, a printer, and a composite apparatus thereof.

[0002]

2. Description of the Related Art Conventionally, for example, a sheet conveying apparatus for conveying a sheet on which an image is formed by an image forming apparatus (hereinafter, referred to as a "transfer sheet") in the image forming apparatus as shown in FIG. In some cases, a straight flexible guide member 38a and a bent flexible guide member 38b are provided at the junction of the transport path.

The sheet conveying device 26 includes a first flapper 3
2, a second flapper 34, a reversing upper guide 35, a reversing lower guide 36, a guide guide 37, a back guide 38, a guide rib 39, a reversing upper roller group 33, a reversing lower roller pair 40, a swing flapper 41, and the like. . The second flapper 34 is formed with three guide surfaces 34a, 34b, 34c.

The sheet conveying device 26 discharges a transfer sheet on which an image is recorded on one side or both sides while turning the sheet upside down. The operation of each part will be described.

First, the first flapper 32 rotates in the direction of arrow A in the figure. The transfer sheet is guided to the introduction path 50, and is conveyed toward the second flapper 34 by the reversing upper roller group 33. The second flapper 34 rotates in the direction of arrow B in the figure. The transfer sheet is provided at the front end of the flexible guide member 38a (FIG. 4).
At the lower end) and is guided to the reverse conveyance path 51.

[0006] Thereafter, the transfer sheet is guided to the reverse pull-in transport path 52. When the rear end of the transfer sheet does not pass through the swing flapper 41 and the second flapper 34 and passes through the leading end of the flexible guide member 38a, the lower reversing roller pair 40 rotates in the reverse direction.

The transfer sheet is conveyed backward through the reverse conveyance path 51 with the rear end serving as the front end, guided by the flexible guide member 38a, and guided by the back guide 38 and the guide rib 39. It is guided to the formed reverse discharge conveyance path 55.

Then, the transfer sheet is formed by a reversing upper roller group 3.
The sheet 3 is conveyed through the reverse discharge conveyance path 55, guided by the flexible guide member 38b, fed into the sheet discharge roller pair 24, and discharged.

The flexible guide member 38b is a thin resin plate in the form of a film such as plastic. Flexible guide member 38b
Is bent in the guide direction of the back guide 38 so as to guide the transfer sheet to the sheet discharge roller pair 24.

As shown in FIG. 5, in the flexible guide member 38b, the free end portion 38bb is moved from the bent portion 38ba.
The length (distance) L1 of the bending piece 38be up to the bending portion 38be
It is set longer than the distance L2 from 8ba to the attachment position 38bc.

Sheets include plain paper, thin resin sheets that are substitutes for plain paper, postcards, cardboard, sealed letters,
There is a plastic thin plate.

[0012]

However, in the conventional sheet conveying device 26, the flexible guide member 38b bends a thin film-shaped resin plate such as plastic and fixes it to the guide plate 38 to the vicinity of the bent portion 38bc. Therefore, only a certain degree of flexibility can always be exhibited for sheets having various stiffness. In particular, the guideability is poor for a thick and stiff sheet, and a large load is applied to the bent portion 38bc to reduce the durability of the flexible guide member 38b, or the leading edge of the sheet may be damaged due to insufficient guide. Put on,
In the worst case, it caused sheet jams and the like.

According to the present invention, a sufficient guideability of the leading end of the sheet is provided in accordance with the stiffness of the sheet while keeping the flexible guide member used to be bent sufficiently flexible. It is an object of the present invention to provide a sheet conveying apparatus which ensures the above-mentioned characteristics, thereby improving the reliability and improving the durability, and an image forming apparatus provided with the sheet conveying apparatus.

[0014]

According to the present invention, there is provided a sheet conveying apparatus comprising: a plurality of sheet conveying paths for guiding sheets;
An elastic guide member is provided so as to be able to tilt the downstream end side in the sheet conveyance direction while closing at least one sheet conveyance path while leaving at least one sheet conveyance path, and the downstream end of the guide member is provided at the junction. A bent piece that is bent along the guide member is formed, and a pressing unit that presses an intermediate portion of the guide member toward the sheet conveying path is provided, and the pressing unit can adjust a position in the sheet conveying direction.

[0015] The pressing means of the sheet conveying apparatus of the present invention is capable of adjusting the position in a region not less than the length of the bent piece on the upstream side in the sheet conveying direction from the bent portion of the bent piece. The pressing means of the sheet conveying apparatus of the present invention includes a pressing piece that contacts the guide member, and an elastic member that presses the pressing piece against the guide member.

The pressing piece of the sheet conveying device according to the present invention is:
The position can be adjusted in the sheet conveying direction.

The guide member of the sheet conveying apparatus of the present invention is a thin metal plate.

The guide member of the sheet conveying device of the present invention is a phosphor bronze plate.

The image forming apparatus according to the present invention includes a sheet stacking unit on which a sheet is stacked, an image forming unit for forming an image on the sheet supplied from the sheet stacking unit, and any one of the above-described ones for conveying the sheet. And a sheet conveying device described in (1).

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 3 is a schematic front sectional view of a copying machine 10 which is an example of an image forming apparatus provided with the sheet conveying device 126 of the present invention.

The copier 10 has an upper part on the main body 11 of the copier.
An automatic document feeder 13 for automatically feeding a document onto a document table 12 at a reading position is provided so as to be openable and closable.

The document may be automatically set on the document table 12 using the automatic document feeder 13 or may be directly set by the user by opening and closing the automatic document feeder 13. .

An optical reading system 14 for reading an image of a document is provided below the document table 12. The optical reading system 14 moves along the platen 12 and
A light source for irradiating light to a document image surface set on
It has a mirror and a lens for guiding the reflected light (image light) to the photosensitive drum 15.

Around the photosensitive drum 15, charging means 1
6, a developing unit 17, a cleaning unit 18, a transfer unit 19, and the like. These are the image forming means 4
5.

The operation of the image forming means 45 is as follows.

First, the surface of the photosensitive drum 15 is uniformly charged by the charging means 16, and the photosensitive drum 15 is irradiated with image light read by the optical reading system 14 to form a latent image. . Then, the latent image is developed by the developing unit 17 to form a toner image on the photosensitive drum 15. The sheet S is fed in synchronization with the image forming operation, and the toner image on the photosensitive drum 15 is transferred to the sheet S by the transfer unit 19. The toner remaining on the photosensitive drum 15 after the transfer is
Removed by

The sheet S is housed in cassettes 1 and 2 serving as sheet stacking means which can be pulled out and stored in the lower portion of the copying machine main body 11, or is attached to and detached from the side (right side in FIG. 3) of the copying machine main body 11. Large-capacity deck 3 mounted freely
Is housed in These various sizes of sheets S are selectively fed by a pickup roller 4 and a feeding roller pair 5 as sheet feeding means provided individually, and are fed one by one sequentially from the top. It is to be sent.

The sheet S is sent to the image forming means 45 by the pair of conveying rollers 20, the pair of registration rollers 21, and the like. Then, the toner image is transferred to the sheet. After the transfer, the sheet S is sent to the fixing unit 23 by the conveyor belt 22. Then, the toner image is fixed on the sheet.

Thereafter, the sheet S includes the first flapper 32 inclined to the position indicated by the solid line in FIG.
And is conveyed to the automatic sorting device outside the device by the pair of discharge rollers 24, and is then sorted and discharged outside the device according to a mode arbitrarily selected by the user. You.

When an image is formed on both sides of the sheet, the transfer sheet is sent to the intermediate tray 27 with its front and back surfaces reversed by a sheet conveying device 126 disposed in front of the discharge roller pair 24.

Transfer sheet S conveyed to intermediate tray 27
Is again fed to the image forming means 45 by the pickup roller 28 and the feed roller pair 29. After being transferred and fixed as described above, the sheet S sent to the image forming unit 45 is conveyed to an automatic sorting device and discharged outside the apparatus at the sorted position.

When an image is to be transferred again on the already transferred image surface, the transfer sheet S is transferred to the intermediate tray 27 by the sheet conveying device 126 without reversing the front and back surfaces of the fixed sheet S. Sent in.

When the transfer sheet having the image recorded on one or both sides is discharged upside down, the front and back sides of the fixed sheet S are reversed by the sheet conveying device 126 so that the sheet discharge roller pair 24.

Next, a sheet conveying device 126 according to an embodiment of the present invention which can discharge a transfer sheet upside down will be described with reference to FIG.

The sheet conveying device 126 includes the first flapper 3
2, a second flapper 34, a reversing upper guide 35, a reversing lower guide 36, a guide guide 37, a back guide 38, a guide rib 39, a reversing upper roller group 33, a reversing lower roller pair 40, a swing flapper 41, and the like. .

The back guide 38 has a flexible guide member 38a for guiding the reverse-transferred transfer sheet to the back guide 38, and the transfer sheet guided to the back guide 38 to the sheet discharge roller pair 24. Flexible guide member 13
8b are attached. The second flapper 34 is 3
It has three guide surfaces 34a, 34b, 34c.

When an image is formed on both sides of a sheet, the sheet after fixing is fed to an intermediate tray 27 (not shown) with its front and back surfaces reversed. The movement of each part at this time will be described.

First, the first flapper 32 rotates in the direction of arrow A in the figure. The transfer sheet is guided to an introduction path 50 formed by the reversing upper guide 35 and the guide 37, and is conveyed toward the second flapper 34 by the reversing upper roller group 33.

The second flapper 34 rotates in the direction of arrow B in the figure. The transfer sheet is guided by the reversing conveyance path 51 formed by the guide surface 34c of the second flapper 34 and the guide rib 39 by pushing away the front end (the lower end in FIG. 1) of the flexible guide member 38a.

Thereafter, the transfer sheet is transferred to the reversing lower guide 36.
The guide rib 39 guides the sheet to the reversing pull-in transport path 52 formed by the guide rib 39. When the rear end of the transfer sheet passes through the swing flapper 41 and the second flapper 34, the lower reversing roller pair 40 rotates reversely.

Lastly, the transfer sheet conveyed in the reverse direction has a swinging flapper 4 where the rear end is the front end.
1 and the reversal completed conveyance path 53 to be conveyed to the intermediate tray 27. The reversing completed conveyance path 53 is formed by the guide surface 34 a of the second flapper 34 and the reversing lower guide 36.

When an image is to be formed again on the already transferred image surface, the transfer sheet is fed to the intermediate tray 27 without turning over the front and back surfaces. The movement of each part at this time will be described.

First, the first flapper 32 rotates in the direction of arrow A in the figure. The transfer sheet is guided to the introduction path 50, and is conveyed toward the second flapper 34 by the reversing upper roller group 33.

The second flapper 34 rotates in the direction of arrow C in the figure. The transfer sheet is guided by the guide surface 34 of the second flapper 34.
b and U-turn transport path 5 formed by reversing upper guide 35
4 and is conveyed to the intermediate tray 27.

When a transfer sheet having an image recorded on one side or both sides is discharged upside down, the transfer sheet is fed to the sheet discharge roller pair 24 with the front and back sides reversed. The operation of each unit at this time will be described.

First, the first flapper 32 rotates in the direction of arrow A in the figure. The transfer sheet is guided to the introduction path 50, and is conveyed toward the second flapper 34 by the reversing upper roller group 33. The second flapper 34 rotates in the direction of arrow B in the figure. The transfer sheet is guided by the reversing conveyance path 51 by pushing away the front end of the flexible guide member 38a.

Thereafter, the transfer sheet is guided to the reverse pull-in transport path 52. When the rear end of the transfer sheet does not pass through the swing flapper 41 and the second flapper 34 and passes through the leading end of the flexible guide member 38a, the lower reversing roller pair 40 rotates in the reverse direction.

The transfer sheet is conveyed backward through the reversing conveyance path 51 with the rear end serving as the front end, guided by the flexible guide member 38a, and formed by the back guide 38 and the guide rib 39. Is guided to the reversed reversal discharge conveyance path 55.

The transfer sheet is made up of the reversing upper roller group 3
The sheet 3 is conveyed through the reverse discharge conveyance path 55, guided by the surface on the bent side of the flexible guide member 138b, fed into the sheet discharge roller pair 24, and discharged.

The flexible guide member 138b has one end 138b.
d is an elastic metal thin plate such as a phosphor bronze plate or a steel plate attached to the back guide 38 by a screw 46, and the other end is bent on the back guide 38.

The end of the flexible guide member 138b is bent along the guide direction of the back guide 38 so as to guide the transfer sheet to the sheet discharge roller pair 24.

An intermediate portion of the flexible guide member 138b is provided with a pressing plate 43 pulled toward the back guide 38 by a pressing spring 42.
Is pressed by the back guide 38. Screw 46
Also serves as a stopper for the holding plate 43. The presser spring 42 and the presser plate 43 constitute a pressing unit 58.

Further, as shown in FIG. 2, in the flexible guide member 138b, the free end 13
The length (distance) of the bent piece 138be up to 8bb is L1, and the distance from the bending portion 138ba to the holding position 138bc is L2.

The distance L2 from the bent portion of the flexible guide member 138b to the mounting position can be adjusted by changing the position of the pressing spring 42 together with the pressing plate 43.

The distance L2 is set to be at least approximately the same as the distance L1.

For example, in the case of guiding a thick transfer sheet having a strong stiffness, the length of the distance L2 is shortened by bringing the pressing plate 43 closer to the bent portion 138bb. As a result, the flexible guide member 138b becomes more flexible, the amount of flexure of the flexible guide member 138b is reduced (or the flexure force is increased), and the flexible guide member 138b is transferred with a strong waist. The sheet can be reliably guided to the sheet discharge roller pair 24.

Conversely, when guiding a thin sheet having a weak waist, the length of the distance L2 is increased by moving the pressing plate 43 closer to the end 138bd. As a result, the flexible guide member 138b is easily bent, and the flexible guide member 138b
The flexible guide member 138b can reliably guide the transfer sheet having a low stiffness to the sheet discharge roller pair 24.

As described above, the sheet conveying device 126 according to the present invention moves the conveying path 55 to which the flexible guide member 138b, which is a bent guide member, is attached along the inside of the bending of the flexible guide member 138b. The transferred transfer sheet presses the bent piece 138be of the flexible guide member 138b, but is absorbed by bending between the bent portion 138ba of the bent piece 138be and the pressing plate 43 of the pressing means 58. be able to.

Further, since the amount of bending or the bending force of the flexible guide member 138b can be varied by adjusting the position of the pressing plate 43, it is possible to cope with transfer sheets having various waist strengths. It is possible to stably guide the leading edge of the sheet.

As a result, the durability of the flexible guide member 138b is improved, and the reliability of the image forming apparatus main body can be improved by ensuring the guideability of the leading edge of the sheet.

[0062]

According to the sheet conveying apparatus of the present invention, the amount of bending or the bending force of the flexible guide member can be varied by adjusting the position of the pressing means. The seat can be guided stably.

Further, the durability of the flexible guide member can be improved, and the sheet can be reliably guided without causing a jam in the sheet.

Further, if the pressing means is capable of adjusting the position in a region not less than the length of the bent piece on the upstream side in the sheet conveying direction from the bent portion of the bent piece, the amount of bending of the guide member is increased, and It is possible to stably guide a seat having a strong waist strength.

Since the image forming apparatus of the present invention is provided with the above-described sheet conveying device capable of guiding the sheet without jamming the sheet, the sheet on which a high-quality image is formed can be formed. Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view of a sheet conveying apparatus according to an embodiment of the present invention.

FIG. 2 is a detailed view of a merging point of a sheet conveyance path to which a flexible guide member according to the embodiment of the present invention is attached.

FIG. 3 is a schematic front sectional view of an image forming apparatus including the sheet conveying device according to the embodiment of the present invention.

FIG. 4 is a schematic front sectional view of a conventional sheet conveying apparatus.

FIG. 5 is a detailed view of a confluence of a sheet conveying path to which a flexible guide member according to a conventional example is attached.

[Explanation of symbols]

 S Sheets 1, 2 Cassettes (sheet stacking means) 3 Large capacity deck 10 Copier (image forming apparatus) 11 Copier body 13 Automatic document feeder 15 Photoconductor drum 24 Discharge roller pair 26 Sheet transporter 32 First flapper 34 2nd flapper 38 back guide 39 guide rib 42 presser spring 43 presser plate (pressing piece) 44 sheet discharge roller pair 45 image forming means 46 screw 55 reverse discharge conveyance path (sheet conveyance path) 56 guide rib 57 discharge conveyance path (sheet conveyance path) 58 pressing means 126 sheet conveying device 138b flexible guide member (guide member) 138ba bending section 138bb free end section 138bc mounting position 138bd end 138be bent piece

Claims (7)

[Claims] At least one sheet conveying path is closed at a junction of a plurality of sheet conveying paths for guiding sheets, and another sheet conveying path is closed so that the sheet is resilient so that the downstream end in the sheet conveying direction can be tilted. In a sheet conveying device provided with a guide member and a bent piece bent along the junction at the downstream end of the guide member, a pressing portion for pressing an intermediate portion of the guide member toward the sheet conveying path. A sheet conveying device, wherein the pressing unit is capable of adjusting a position in the sheet conveying direction. 2. The apparatus according to claim 1, wherein the pressing unit is capable of adjusting a position in a region on the upstream side of the bent portion of the bent piece in the sheet conveying direction and at least a length of the bent piece. The sheet conveying device according to claim 1. 3. The sheet conveying apparatus according to claim 1, wherein the pressing unit includes a pressing piece that contacts the guide member, and an elastic member that presses the pressing piece against the guide member. . 4. The sheet conveying device according to claim 3, wherein the position of the pressing piece is adjustable in the sheet conveying direction. 5. The sheet conveying device according to claim 1, wherein the guide member is a thin metal plate. 6. The sheet conveying device according to claim 5, wherein the guide member is a phosphor bronze plate. 7. A sheet stacking unit on which sheets are stacked, an image forming unit for forming an image on the sheet supplied from the sheet stacking unit, and conveying the sheet. 1
An image forming apparatus comprising: the sheet conveying device according to any one of claims 1 to 7.