JPH01281238A - Aslantly transporting device for sheet in image forming device - Google Patents

Abstract

PURPOSE:To avoid the influence of the change of a sheet surface due to toner, etc., on a driven roller by arranging the driven roller so as to contact the opposed surface to the image formation surface of the sheet on which an image is formed. CONSTITUTION:A sheet S on which an image is formed in an image formation part 1 is transported to an aslantly transporting device 7 for sheet and nipped by a driven roller 10 and a transport roller 9. Then, the driven roller 10 contacts the opposed surface Sb to an image formation surface Sa of the sheet, for example as the sheet S shifts without being influenced by the reduction of the contact friction with the sheet S because of the toner, etc., on the image formation surface Sa, one side is shifted largely than the other side, and the sheet is shifted so as to be surely aslantly transported. Then, the sheet S which contacts the opposed surface Sb of the image formation surface Sa of the sheet and is nipped by the driven roller 10 which shifts so as to aslantly feed the sheet S and the transport roller 9 is prevented from being influence by the toner, etc., on the image formation surface Sa, and aslantly fed in the prescribed direction surely and in stable manners.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a sheet skew feeding device in an image forming apparatus such as a copying machine or a laser beam printer. The present invention relates to a sheet diagonal feeding device in an image forming apparatus that includes a roller that is held such that one side is displaced more than the other side.

(b) Prior Art Recently, according to the present application, there has been developed a copying machine that is equipped with a roller that is held so that one side is displaced more than the other side as the sheet to be held is moved, and that feeds the sheet diagonally. A sheet oblique feeding device has been devised for an image forming apparatus such as the above.As shown in FIG. , the image forming section 1 is provided with a developer M3 having a built-in toner image, a transfer charger 5, etc. around the photosensitive drum 2.Furthermore, a fixing device 6 is arranged downstream of the image forming section 1. Further, downstream of the fixing device 6, the sheet diagonal feeding device 7' is arranged.

The sheet oblique feeding device 7' has a drive roller 9, which is rotated in both forward and reverse directions by the drive of a drive source. Further, a driven roller 10 is disposed above the drive opening roller 9 so as to be in contact with the drive roller 9, and the driven roller 10, as shown in FIG.
It is rotatably supported by a support shaft 11 and rotates with the rotating drive roller 9.

On the other hand, bearings 12 are provided on both sides of the support shaft 11, respectively.
13 are arranged, and these bearings 12 and 13 have bearing grooves 1 that fit and support the side parts 11a and llb of the support shaft 11.
2a, 13a are provided, and the radius Il of one bearing groove 12a in the sheet conveying direction is equal to the radius I! of the other bearing groove 13a. It is slightly larger than p 2 (1, >1
2) The support shaft 11 supporting the driven roller 10 can slide on one side 11a in the sheet conveyance direction using the other side 11b as a fulcrum.

Note that the support shaft 11 is configured not to move upward or downward in the sheet reverse feeding direction.

As shown in FIG. 7, when the drive roller 9 rotates forward in the direction of the solid line, the driven roller 10 that is in contact with the drive roller 9 rotates in the direction of the solid line due to contact friction. Further, when the drive roller 9 rotates in the reverse direction in the direction of the chain line, the driven roller 10 rotates along with it in the direction of the chain line. Furthermore, when the sheet +-S is carried between the driving roller 9 and the driven roller 10 and is conveyed in the direction of the arrow shown by the solid line by the driving roller 9 that rotates in the forward direction, the driven roller 10 Due to contact friction, the sheet rotates in the direction of the solid line and is attracted in the feeding direction, that is, in the direction of the arrow shown by the solid line. Also,
When the driving roller 9 reversely rotates in the @ line direction, the driven roller 10 rotates along with it in the chain line direction and is attracted in the sheet reverse feeding direction, that is, in the direction of the arrow shown by the chain line.

Therefore, as shown in FIG. 8, the support shaft 11 supporting the driven roller 10 is attracted in the sheet conveyance direction Zζ when the sheet 1-S is conveyed from A to B direction, and the side portion 11
a and llb are brought into contact with the bearing front ends 12b and 13b in the respective bearing grooves 12a and 13a. Therefore, the support shaft 11 of the driven roller 10 is connected to the shaft 9 of the drive roller 9.
a, and is conveyed in a direction perpendicular to the axis 9a of the drive roller 9 by the forward rotation of the drive roller 9.

Further, when the drive roller 9 rotates in the reverse direction, the sheet S is reversely fed from B to D as shown in FIG.
is pulled in the sheet reverse feeding direction (ζ) at sea 1-S, and the support shaft 11 supporting the driven roller 10 is pulled in the sheet backward feeding direction, and the side portion 11a is pulled.

11b to the rear end of the bearing 1 within the bearing grooves 12a and 13a.
2c and 13c, and is inclined at a predetermined angle a with respect to the shaft 9a of the drive roller 9. Therefore, the sea 1-S between the driving roller 9 and the driven roller 10 is inclined. It is fed backward at an angle corresponding to the inclination angle 7ζ of the JJ roller lO.

In the above-mentioned copying machine, the sheet S is sent from the paper feed section between the photosensitive drum 2 and the transfer charger 5 of the image forming section 1, as shown in FIG. 5, and is subjected to a known electrophotographic process. The toner image formed on the photosensitive drum 2 is transferred to the upper surface Sa facing the photosensitive drum 2. Then, the sheet S is conveyed to the checking device 6, and! - The toner image is fixed and sent to the sheet oblique feeding device 7'. The sheet oblique feeding device 7
The sheet S sent to ' is conveyed in the direction of the arrow shown by the solid line by the drive of the drive roller 9 which rotates in the forward direction.

When the sheet S is fed by a predetermined amount in the direction P through the sheet diagonal feeding device 7', the drive roller 9 rotates in the opposite direction, and the sheet 1
- S is the double-sided paper feed unit roller pair 1 in the R direction with the rear edge first.
It will be sent back to 5. Then, when the sheet 1-S starts to be fed backward in the R direction, the driven roller 10 is pulled by the sheet S that is being fed backward and tilts, and the sheet 1-S is aligned again in the lateral direction. As such, the sheet is obliquely fed toward the sheet alignment member of a predetermined duplex sheet feeding section.

(c) Problems to be Solved by the Invention By the way, in the above-mentioned sheet skew feeding device 7', when the driven roller 10 comes into contact with the upper surface Sa of the sheet S onto which the toner image has been transferred, the toner etc. on the upper surface Sa of the sheet is Sea 1 of the driven roller 10 due to the influence of Frictional resistance with S decreases,
It is easy to slip, and there is a risk that the sheet S will not be fed diagonally enough.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a structure in which a driven roller contacts a surface of a sheet opposite to an image forming surface on which a toner image is transferred, thereby solving the above-mentioned problems.

(b) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and as an example, referring to FIGS. 1 and 2, the image forming section ( A conveyance roller (9) conveys the sheet 1-(S) on which an image has been formed in step 1), and a sheet (S) that is in contact with and sandwiched between the conveyance roller (9) and the conveyance roller (9). ) and a driven roller (10) held so that one side is displaced more than the other side in the moving direction of the sheet (S) as the sheet (S) moves, and the sheet 1-(S) on which an image is formed
) in a sheet diagonal feeding device (7) in an image forming apparatus in which a sheet is diagonally fed, a driven roller (lO) is brought into contact with a surface (sb) opposite to an image forming surface (Sa) of a sheet (S) on which an image is formed. It is characterized by being arranged as follows.

(e) Operation Based on the above-described configuration, the sheet +- (S) on which an image has been formed in the image forming section (1) is conveyed to the sheet diagonal feeding device (7), and is conveyed to the sheet diagonal feeding device (7), where it is moved by the driven roller (10) and the conveying roller (9). ) is held between. Then, the driven roller (10) comes into contact with the surface (sb) of the sheet (S) opposite to the image forming surface (Sa) to prevent contact friction between the image forming surface (Sa) and the sheet (S) due to toner, etc. The sea 1-(S
), one side is displaced more than the other side, and the sheet (S) is displaced to reliably skew feed. and,
A sheet (S) is held between a driven roller (10) that is in contact with the surface (Sb) opposite to the image forming surface (Sa) of the sheet, and is displaced so as to feed the sheet (S) obliquely, and a conveyance roller (9). ) is reliably and stably obliquely fed in a predetermined direction without being affected by toner or the like on the image forming surface (Sa).

Note that the above symbols are shown for reference and do not limit the configuration in any way.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3.

Each part of the copying machine described above and the same parts as the sheet skew feeding device 7' are designated by the same reference numerals, and the explanation thereof will be omitted.

As shown in FIGS. 1 and 2, the sheet diagonal feeding device 7 of this embodiment is disposed downstream of the fixing device 6 similarly to the sheet diagonal feeding device 7' described above. It is equipped with a driven roller lO. Then, the sheet diagonal feeding device 7
In this case, the driving roller 9 is placed upwardly, and the driven roller 10 is placed upwardly.
A driven roller 10 disposed on the lower side is in contact with the drive roller 9 and rotates with the drive roller 9. Further, on both sides of the support shaft 11 that supports the driven roller 10, the above-mentioned sheet diagonal feeding device 7 is provided.
′, each has a predetermined width 1. , 12, bearing grooves 12a, 13a with bearing grooves 12a, 13a are arranged. Furthermore, as shown in FIG. 3, the support shaft 11 of the driven roller 10 is provided with a support member 16 that supports the support shaft 11, and the support member 16 has a mounting wall 17,
Springs 19, 19 attached to each of the rollers 17 are tensioned, and the driven roller 10 is biased by these springs 19, 19 into pressure contact with the upper driving roller 9.

Since this embodiment has the above configuration, the sheet S is transferred to the photosensitive drum 2 in the image forming section 1, as shown in FIG.
The toner image is transferred to the upper surface Sa facing the sheet, the toner image is fixed at fixing N6, and the toner image is conveyed to sheet diagonal feeding device M7. The sheet S conveyed to the sheet skew feeding device 7 is sent between a drive roller 9 and a driven roller 10, and is moved in the direction of an arrow P by the drive of the drive roller 9, which rotates forward in the direction of the arrow shown by the solid line. transported. At this time, the driven roller 10
contacts the lower surface sb on which the toner image is not transferred of the sheet S being conveyed in the direction of arrow P, and is not affected by the toner etc. (due to contact friction with the sheet S, the sheet 1-S
The support shaft 11 is made parallel to the shaft 9a of the drive roller 9 (see FIG. 8), and the sea 1-S is conveyed straight in the P direction. Next, after the sheet S has been conveyed by a predetermined amount in the P direction, when the drive roller 9 rotates in the reverse direction in the direction of the arrow shown by the chain line, the sheet 1-S is transferred to the double-sided paper feed unit roller 15 with the rear end first. It is sent backwards in the R direction. and,
When the sheet 1-S starts to be fed backward in the R direction, the driven roller 10 is pulled by the sheet 1-S that is being fed backward by the friction of contact with the sheet S without being affected by toner, etc. The support shaft 11 that supports 10 is located on one side 1
1a is largely moved through the bearing groove 12a in the reverse feeding direction of the sheet S and comes into contact with the rear end 12c of the bearing, and is inclined at a predetermined angle α with respect to the shaft 9a of the drive roller 9 (see FIG. 9).

Then, the sheet S is held between the drive roller 9 and the driven roller 10, which is supported by the support shaft 11 inclined at a predetermined angle a and is in contact with the lower surface sb of the sheet S, and its lateral sides are aligned again. The sheet is conveyed in the R direction through the double-sided sheet feeding section, and is obliquely fed toward a predetermined sheet alignment member. This (ζ
Since the slave roller 10 comes into contact with the lower surface sb of the sheet on which toner is not transferred, the frictional resistance between the seal l-S and the driven roller 10 does not decrease due to the toner transferred to the sheet S, and the sheet S can be reliably fed obliquely.

In the above embodiment, the driven roller 10 was arranged below the driving roller 9, but as shown in FIG.
When transferring a toner image to the lower surface sb of the sheet S, the driven roller 10 is disposed above the drive roller 9.

(G) As described in detail, according to the present invention, one side is displaced more than the other side as the sheet that is in contact with the conveyance roller and is held between the conveyance roller and the sheet moves. Since the driven roller held in this manner is arranged so as to be in contact with the surface opposite to the image forming surface of the sheet, the driven roller can be prevented from being affected by changes in the sheet surface due to toner etc. with a simple configuration. Sheets can be accurately and stably fed obliquely.

[Brief explanation of the drawing]

1 to 3 are views showing a sheet diagonal feeding device according to an embodiment of the present invention, and FIG. 1 is a side view showing its arrangement position;
FIG. 2 is a perspective view, and FIG. 3 is an enlarged side view. Fourth
The figure is a side view of another embodiment in which the arrangement position of the driven roller is changed in connection with the change in the arrangement position of the image forming section, and Figs. 5 to 7 show the previously devised sheet diagonal feeding device. In the figure,
Fig. 5 is a side view showing the arrangement position, Fig. 6 is a perspective view,
FIG. 7 is an enlarged side view. 8 and 9 are plan views showing the position of the driven roller common to the present invention and the previously devised sheet skew feeding device. FIG. 8 is a plan view of the driven roller parallel to the driving roller, and FIG. FIG. 9 is a plan view of the driven roller inclined with respect to the driving roller. 1... Image forming section, 7... Sheet oblique feeding device, 9
...Conveyance roller (drive roller), 10...Followed roller, S...Sheet, Sa
. . . Image forming surface (upper surface), sb . . . Opposite surface to the image forming surface (lower surface).

Claims (1)

[Claims] 1. A conveyance roller that conveys a sheet on which an image has been formed in the image forming section of an image forming apparatus, and movement of the sheet as the sheet that is in contact with and held between the conveyance roller and the conveyance roller moves. a driven roller held so that one side is displaced more than the other side in a direction, and a sheet diagonal feeding device in an image forming apparatus that diagonally feeds the sheet on which the image is formed, the driven roller A sheet diagonal feeding device for an image forming apparatus, characterized in that the sheet diagonal feeding device is arranged so as to be in contact with a surface opposite to an image forming surface of the sheet on which an image is formed.