JPH0218244A - Sheet conveying device - Google Patents

Abstract

PURPOSE:To simply and reliably remedy oblique running of a sheet by a method wherein the drive rollers of a slip roller are mounted integrally with a shaft, supporting the drive roller, in a rotation direction and movably in an axial direction and a return means to return the drive roller to a given position is situated to the drive roller. CONSTITUTION:Drive rollers 22a-22c of a slip roller 20 are rotated integrally with a support shaft 21, and a sheet S is brought into abutment with an abutting means 6. In this case, when the sheet S runs obliquely, a thrust force Fs is exerted on the slip roller 20 by means of a rotation force M of the sheet S itself. The drive rollers 22b and 22c are moved along the shaft 21 against a spring 31b according to the thrust force Fs to allow rotation of the sheet S. A thrust force exerted on the drive rollers 22b and 22c along with movement of the drive rollers is reduced, the feed of the sheet on the side where the sheet S does not arrive is performed continuously, and oblique running of the sheet S is remedied. After the sheet S passes the slip roller 20, the roller 20 is returned to its initial position through the force of the spring 31b.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a sheet conveying device for conveying sheets such as copy paper in image forming apparatuses such as copying machines and printers.
More specifically, the present invention relates to a sheet conveying device having a sheet skew correction function.

(b) Prior Art - In an electrostatic copying machine, an original is exposed to light on a photosensitive drum or the like of an image forming section to form an electrostatic latent image, and a developer is supplied to the image to make it visible. On the other hand, the copy paper is fed by a conveying means and is temporarily stopped by a registration roller, a registration shutter, etc. before the image forming section. Then, timing is taken such that the leading edge of the image on the paper and the photosensitive drum coincide, and the paper is sent toward the photosensitive drum for transfer.

Here, the above-mentioned conveying means has a function of not only feeding the paper but also working with registration rollers etc. to correct the skew of the paper and align it. Some use rollers.

This slip roller R consists of a driving roller a and a driven roller b attached to a driving shaft C. If the friction coefficient of the driving roller surface is R1 and the friction coefficient of the driven roller surface is R2, the relationship is set as μm>R2. . And roller pressure F
F is set so that the conveying force F·μm in μm is the minimum value necessary for paper feeding, and when a load is applied to the paper S, it is possible to slip between the roller a and the paper S.

Such a plurality of slip rollers R,,R,.

R1 is integrally attached to the drive shaft C, as shown in FIG. 5(b). And these rollers Rs, R*
, R3, when the sheet S is skewed and its corner A hits the stopped registration roller d, the roller R8 that coincides with the corner A becomes in a slipping state. On the other hand, the other two small rollers R, , R,
By continuing to feed the paper, the paper S is aligned as shown by the broken line.

(C) Problems to be Solved by the Invention By the way, when the above-mentioned obliquely traveling sheets S are aligned, the sheets S
A rotational force M about the corner A acts on the roller itself, and this rotational force M applies an axial thrust force F to each roller R1R2, R3. Therefore, unlike the conventional example, the roller RI
* In the configuration in which R2+R1 is integrated with the drive shaft C, there is no escape from the thrust force Fs of the rollers R* and Rz, and the force F is directly received. For this reason, the rollers R* and R's slip under the load of the thrust force Fs, making it difficult to reliably feed the aligned sheets, resulting in a problem of insufficient skew correction.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sheet conveyance device that can reliably remove skew of paper using slip rollers.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and for example, as shown with reference to FIGS.
an abutting means (6) for abutting the tip of the abutting means (6);
a slip roller (20) that conveys the sheet (S) and slips between the sheet (S) when a load of more than a predetermined value is applied to the sheet (S), and abuts the sheet (S). In a sheet conveying device that corrects the skew of the sheet (S) by abutting against the means (6), the slip roller (20
) drive rollers (22a, 22b.

22C) is attached to the shaft (21) that supports the drive roller integrally in the rotational direction and movable in the axial direction, and the drive roller (22a, 22b, 22C) is attached to the drive roller (22a, 22b, 22C) to return the drive roller to a predetermined position. Return means (31a, 3lb)
It is characterized by having the following.

(f) Effect Based on the above configuration, the slip roller (20) has drive rollers (22a, 22b, 22c) that rotate together with the shaft (21) to abut the sheet (S) against the abutment means (6). . At this time, if the sheet (S) is running diagonally, a thrust force (R8) acts on the slip roller (20) due to the rotational force (M) of the sheet itself, and in response to this thrust force (Fs), the drive roller (22b , 22c) moves in the axial direction and the seat (
S) is allowed to rotate. On the other hand, this allows the drive roller (
The thrust force applied to the sheets 22b and 220) is reduced, and the sheet is continuously fed on the side where the sheet has not arrived, thereby reliably correcting the skew.

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 the drawings.

In FIG. 1, the outline of a copying machine to which the present invention is applied will be described. Reference numeral 1 indicates a copying machine main body;
An image forming section 3 equipped with a photosensitive drum 2 is provided inside the image forming section 3, and a registration roller 6 constituting abutting means is disposed immediately in front of the image forming section 3 via a conveyance path 5. The registration roller 6 rotates and stops in conjunction with an electromagnetic clutch.

Also, the registration roller 6 and the paper feed roller 10 of the paper feed means 9
A transport means 11 is provided between the transport means 11 and the transport means 11, which has two sets of slip rollers 20, 20' in the middle of a transport path 12 bent in a U-shape. The manual feed path 13 is in communication.

2(a), (b) and FIG. 3, the slip rollers 20, 20'' will be described. The slip roller 20 has, for example, three drive rollers 22a on the drive shaft 21.
, 22b, 22c are attached, and these rollers 22a
, 22b, and 22c, driven rollers 25 of the shaft 23 are disposed facing each other to form a pair of rollers. The shaft 23 is inserted into a groove 26 in the main body 1, and a leaf spring 27 applies roller pressure. Here, the friction coefficient μm of the rollers 22a, 22b, and 22c is larger than the friction coefficient μ2 of the roller 25, and the roller pressure F of the leaf spring 27 is set to ensure the minimum conveying force necessary for paper feeding.

Regarding one drive roller 22a, it is separated from other rollers by a wall 29 of the main body 1. Further, a parallel pin 30 is attached to the drive shaft 21 side approximately at the center of the roller 22a, and a groove for fitting a parallel pin is provided in the shaft insertion hole of the drive roller 22a. It is integrally attached to the drive shaft 21 in the rotational direction and movable in the axial direction. A coil spring 31a serving as a return means is provided between the left and right walls 29 of the roller 22a.
31b is energized. The other rollers 22b and 22c are constructed in exactly the same manner, are movable in the axial direction, and are automatically returned to their original positions by spring force.

The upstream slip roller 20' has the same structure as the downstream slip roller 20, and the same parts are given the same reference numerals with a dash and the explanation thereof will be omitted. Here, when these two sets of slip rollers 20 and 20' perform skew removal during sheet (paper) conveyance, the upstream slip roller 20' requires a larger amount of sheet rotation. Therefore, in response to the difference in the amount of sheet rotation, the coil springs 31a' and 31 of the upstream slip roller 20'
The spring force of b' is set smaller than that of the downstream one.

Since this embodiment has the above-described configuration, the paper S fed by the paper feed roller 10 is transferred to the driving rollers 22a' and 22b of the slip roller 20' upstream of the conveying means 11.
', 22c and a driven roller 25'. Here, the drive shaft 21' and each roller 22a', 22b',
Since the rollers 22c' rotate integrally, the paper S is sandwiched between these pair of rollers and sent along the conveyance path 12. Next, the drive rollers 22a, 2 are also used in the downstream slip roller 20.
2b and 22c rotate integrally with the drive shaft 21, so that the paper S is moved between these rollers 22a, 22b, 22c and the roller 2.
The leading edge of the sheet S hits the registration roller 6 and is temporarily stopped.

Therefore, when the paper S arrives at the registration roller 6,
The operation when the paper S is skewed as shown by the solid line in FIG. 4 will be described. First, at this time, the roller 22a on the paper arrival side
When a large load is applied to the paper, it enters a slipping state, and the paper is fed by the other two rollers 22b and 22c. Therefore, a rotational force M centered around the corner A acts on the paper S,
Based on this, each roller 22b, 22c has a thrust force F.
, it takes. Therefore, these rollers 22b.

22c moves in the axial direction against one of the springs 31b in response to the thrust force Fs as shown by the dashed line, and as a result, the paper S is allowed to rotate, and along with this, the thrust force F
, and the paper is substantially fed by the rollers 22b and 22C. In this way, the non-arrival side of the sheet S is also rotated and sent to the registration rollers 6, and is aligned so that the entire leading edge is in contact with the registration rollers 6 as shown by the broken line.

Note that when the slip roller 20' on the upstream side performs skew removal together with the slip roller 20 on the downstream side, the spring force on the slip roller 20' side is small, so that the driving rollers 22b' and 22c' are The larger the radius of rotation, the more axial movement. Therefore, the sheet S is corrected while rotating uniformly as a whole.

In the above embodiment, after the registration roller 6 removes the skew, the paper S is sent toward the photosensitive drum 2 at a certain timing. This causes the paper S to slip onto the slip roller 20 or 2.
0', the drive (J-ra 22b, 22c or 22b', 22c') is returned to its initial position by the spring 31L+ or 31b'.

＼g) Detailed Description of the Invention According to the present invention, the drive roller of the slip (J-ra) is integral with the shaft supporting the drive roller in the rotational direction and movable in the axial direction. Since a return means is provided on the mounting and drive rollers, when a skewed sheet hits the abutment means, the sheet can be fed while allowing the sheet to rotate, and the skewed sheet can be fixed with a simple configuration. It can be easily and reliably corrected.

Further, in the case where a plurality of slip rollers are provided, since the axial movement amount of the slip roller on the E flow side is set to be large, the skew of the sheet can be corrected more easily.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment in which the present invention is applied to a copying machine, Fig. 2 is a side view of an embodiment of a sheet conveying device, and Fig. 3 (
a) is the same plan view, (b) is a BB sectional view of (a), the fourth
The figure is an explanatory diagram of the skew correction effect, FIG. 5(a) is a side view of a conventional slip roller, and FIG. 5(b) is a plan view of a conventional sheet conveying device. 6... Abutment means (registration roller) 20... Slip roller 21... Shaft (drive shaft) that supports the drive roller 22 a
, 22 b , 22 c ・”Drive roller 3
1a, 31b...Returning means (coil spring) S...Sheet (paper)

Claims (1)

[Scope of Claims] 1. Abutment means for abutting the leading end of the sheet, and a slip roller that conveys the sheet to the abutment means and slips between the sheet and the sheet when a load of more than a predetermined value is applied to the sheet. A sheet conveying device comprising: abutting the sheet against the abutting means to correct the skew of the sheet; A sheet conveying device, characterized in that the sheet conveying device is mounted integrally and movably in the axial direction, and the driving roller is provided with a return means for returning the driving roller to a predetermined position. 2. The sheet conveying device according to claim 1, wherein the sheet conveying device has a plurality of slip rollers, and an upstream slip roller has a larger axial movement amount under the same load than a downstream slip roller.