JPH04350038A - Sheet material transfer device - Google Patents

Abstract

PURPOSE:To prevent the damage of sheet materials and the occurrence of wrinkles at the time when the lateral dislocation of the sheet material is regulated by shifting in the axial direction a pair of registration rollers for holding the forefront end of the sheet material therebetween. CONSTITUTION:A sheet material transfer device is provided with a pair of first rollers 5 for holding the forefront end of a sheet material P (not shown) to be transferred therebetween, and a pair of second rollers 2 for holding the rear end therebetween. When the pair of first rollers 5 are shifted in the axial direction for regulating the lateral dislocation of the sheet material P, the roller 2a on one side out of the pair of second rollers 2 is moved so as to follow the movement of the pair of registration rollers 5 via the sheet P. Thereby, when the lateral dislocation of the sheet P is regulated, the damage of the sheet P and the occurrence of wrinkles or the like are prevented. After the sheet P has passed through the pair of slip rollers 2, the upper roller 2a is returned to its initial position before the sheet P is passed. Thus, the lateral dislocation of the sheet P can be smoothly regulated.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to image forming apparatuses and OCR
The present invention relates to a sheet material conveying device such as the above.

0002

2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying machine, a toner image formed on a photosensitive drum is transferred to a sheet material and then fixed in a fixing device to form an image. The image forming apparatus includes a pair of registration rollers that conveys a sheet material to the photosensitive drum by timing the relative timing between the toner image on the photosensitive drum and the sheet material to which the toner image is transferred. Furthermore, recently, image forming apparatuses have been developed that are equipped with a mechanism that allows the pair of registration rollers to move in a direction perpendicular to the conveying direction of the sheet material to prevent lateral displacement of the sheet material.

FIG. 8 shows the vicinity of a pair of registration rollers of a copying machine to which the present invention is directed. In the figure, a photosensitive drum 1 has a toner image formed around it by well-known electrophotography, and is rotating in the direction of the arrow. A registration roller pair 5 consisting of an upper roller 5a and a lower roller 5b in pressure contact with the upper roller 5a is disposed near the photosensitive drum 1. A pair of slip rollers 2 is disposed near the upstream side of the pair of registration rollers 5 and is pressed against the pair of registration rollers 5 with a relatively small force. A guide plate is provided between the pair of slip rollers 2 and the pair of registration rollers 5. A guide plate pair 3 consisting of 3a and 3b is provided.

FIG. 9 shows an example of an alignment mechanism for aligning the lateral misalignment of the pair of registration rollers 5. As shown in FIG.

In the figure, a shaft 10 to which an upper roller 5a of a pair of registration rollers 5 is fixed, and a shaft 11 to which a lower roller 5b is fixed, have bearings 12 and 13 attached to a pair of side plates 1.
5 and 16, respectively. Gears 20 and 21 that mesh with each other are fixed to each shaft 10 and 11, and a connecting member 1 is attached to the end of each shaft 10 and 11.
7 are loosely interlocked with each other, and each is prevented from coming off by a snap ring 19.

Both arms 22a and 22b of a channel-shaped holding member 22 are attached to the end of the shaft 10, and are prevented from coming off by a snap ring 23. shaft 10 by the guide member of
Guided so that it can move only in one direction. Holding member 22
A pulse motor 63 connected to the shaft 25 moves arrows 27a and 27 to the rack 22c formed at the lower part of the rack 22c.
By rotating forward and backward in the b direction, the pair of registration rollers 5 and the sheet material P held in their nip portion are moved in the axial direction (in the lateral displacement direction of the sheet material P). Further, when the sheet material P moves to a predetermined position in the lateral direction, the paper edge on the side blocks light from the photosensor 45, so that the rotation of the pinion 26 is stopped under the control of a control section (not shown). .

Both arm portions 22a and 22b of the holding member 22
In between, there is a clutch 3 fixed to the shaft 10.
0b and a gear 30 rotatably attached to the shaft 10
An electromagnetic clutch 30 consisting of a gear 30a is disposed, and the gear 30a meshes with a wide drive gear 31 connected to a drive motor 61. The electromagnetic clutch 30 is
It is controlled by the control unit 60 and is turned on as necessary to convey the sheet material P to transmit the rotational force of the drive motor 61 to the pair of registration rollers 5.

The above pinion 26, pulse motor 63,
The holding member 22 and the like constitute a pair of roller moving means 9 that moves the pair of registration rollers 5 and the sheet material P held in the nip thereof in a direction perpendicular to the sheet material conveyance direction.

In FIG. 8, a sheet material P fed from a paper feed tray (not shown) is conveyed to a pair of guide plates 3 by a pair of slip rollers 2, and its tip ends at the nip portion of a pair of registration rollers 5 in a stationary state. It will stop when inserted. As the slip roller pair 2 continues to rotate in this state, the sheet material P forms a loop, and due to the stiffness of the sheet material P with this loop in contact with the inner surface of the guide plate pair 3, the slip roller Pair 2 is in a state of slipping without feeding the sheet material P.

The registration roller pair 5 rotates and feeds out the sheet material P in synchronization with the timing when the toner image on the photosensitive drum 1 rotates to a predetermined position. The fed-out sheet material P is guided to the photosensitive drum 1 by a pair of guide plates 6, a toner image is transferred by a transfer charger 7, and then separated, and the toner image is further fixed by a fixing device (not shown).

The registration roller pair 5 of the copying machine configured as described above is configured so that the lateral position of the sheet material P can be controlled with sufficient accuracy. Furthermore, the accuracy of the position of the sheet material P in the conveying direction is determined by making sure that the tip of the sheet material P sufficiently enters the nip portion of the pair of registration rollers 5, and that the rotation of the pair of registration rollers 5 starts up sufficiently quickly. That is the important point.

Normally, in order to allow the sheet material P to sufficiently enter the nip between the pair of rollers, a pair of slip rollers is generally provided on the upstream side of the pair of rollers in the sheet conveying direction. .

For example, the roller pair 2 in FIG. 10 is configured to apply a conveying force to the sheet material P in order to cause the sheet material P to enter the nip portion of the registration roller pair 5, which is not rotating. Even if roller 5 is stopped, slip roller pair 2 normally rotates. At this time,
The slip roller pair 2 is in a slip state with respect to the sheet material P, and the sheet material P is sandwiched between the guide plate pair 3, so the conveyance force applied to the sheet material P by the slip roller pair 2 is It is transmitted in the conveying direction of the sheet material P, and the leading edge of the sheet material P is moved by the registration roller pair 5 due to the above-mentioned conveying force.
It is forcibly entered into the nip portion of the

Furthermore, although the pair of guide plates has a sufficient gap for the sheet material P to pass through, the gap is relatively narrow, so that the conveyance given to the sheet material P by the pair of slip rollers 2 is sufficient. Most of the force acts in the direction in which the sheet material P travels.

[0015]

However, in the sheet material conveying device described above, the registration roller pair 5 is configured to move in a direction perpendicular to the conveying direction of the sheet material P in order to prevent lateral displacement. As shown in FIG. 10, the sheet material P is also held by the slip roller pair 2 immediately before the registration roller pair 5, so if the gripping force of the sheet material P by the slip roller pair 2 is strong, the registration roller pair There is a problem that the sheet material P may be damaged as shown by arrow E when moving in the direction of arrow 29b of 5, or wrinkles may occur if the sheet material P is conveyed in the same state as shown by arrow 5.

In order to prevent this, for example, if the slip roller pair 2 is moved in the same direction simultaneously with the lateral movement of the registration roller pair 5, no problem will occur, but in this case, the mechanism is complicated and the device is There is a problem with increasing the size.

Therefore, in the present invention, when adjusting the lateral deviation of the sheet material by the first roller pair, the second roller pair is driven in the same direction to prevent the occurrence of lateral deviation and wrinkles in the sheet material. The object of the present invention is to provide a sheet material conveying device.

[0018]

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned circumstances, and provides a first
a pair of rollers (5) and a second pair of rollers (2) on the upstream side thereof.
and roller pair moving means (9) for moving the first roller pair (5) in a direction perpendicular to the sheet material conveyance direction;
In the sheet material conveying device, at least the negative roller (2a) of the second roller pair (2) is driven by the movement of the sheet material (P) due to the movement of the first roller pair (5). It is characterized by being movable.

[0019] Also, the movable roller of the first roller pair and the second roller pair is narrower than the immovable roller.

[0020]Furthermore, it is characterized in that the sheet material clamping pressure of the first pair of rollers (5) is greater than the clamping pressure of the second pair of rollers (2).

[0021] Further, the movable roller (2a) of the second roller pair (2) is arranged so that the sheet material (P) is
After passing through the pair of rollers (2), the sheet material (P) returns to its original position before passing through.

[0022] Also, the movable roller (2a) of the second roller pair (2) is connected to the immovable roller (2a).
It is characterized by being narrower than 2b).

[0023]

[Operation] Based on the above configuration, the sheet material (P) to be conveyed
is sent to the first roller pair (5) by the upstream second roller pair (2). The first roller pair (5) is moved by the roller pair moving means (9) in a direction perpendicular to the sheet material conveyance direction, and the sandwiched sheet material (P) is moved in a direction perpendicular to the sheet material conveyance direction. That is, it is moved in the width direction of the sheet material. When the first pair of rollers (5) moves, the movable roller (2a) of the second pair of rollers (2) follows and moves in the same direction via the sheet material (P). As a result, the sheet material (P) being conveyed while being pinched by the pair of rollers (5, 2) is prevented from being wrinkled and is prevented from shifting laterally.

Furthermore, after the sandwiched sheet material (P) has passed, the negative roller (2a) of the second roller pair (2) automatically returns to its original position before sandwiching the sheet material (P). to return to. As a result, when the next sheet material (P) is conveyed, the lateral displacement of the sheet material (P) is adjusted by the first pair of rollers (5).
), and horizontal displacement can be adjusted while preventing wrinkles from forming in the sheet material (P).

Note that the above-mentioned symbols in parentheses are used to refer to the drawings, and do not limit the structure of the present invention in any way.

[0026]

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

Components having the same functions as those of the conventional device shown in FIGS. 8 and 9 are designated by the same reference numerals. Further, since the roller pair moving means constituting the sheet material conveying device of the present invention has the same configuration as the roller pair moving means 9 shown in FIG. 9 described above, illustration and explanation of the roller pair moving means will be omitted. .

In FIGS. 1 and 2, the first pair of rollers (
(hereinafter referred to as registration roller) 5 is a control means (control unit)
It is driven by a drive motor 61 controlled by 60. A second roller pair (hereinafter referred to as a slip roller pair) 2 disposed upstream of the registration roller pair 5 is attached to a support shaft 46.
It consists of a plurality of lower rollers 2b fixedly attached to the lower rollers 2b, and a plurality of upper rollers 2a each pressed against the lower rollers 2b.

The mounting member fixed to the upper surface of the guide plate 3a of the guide plate pair 3 has an elastic member 16 made of a leaf spring.
The upper roller 2a, which is attached to the free end of the elastic member 16,
It is pressed against the lower roller 2b due to its elasticity. In FIG. 3, the upper roller 2a is attached to the free end of the elastic member 16 by a support shaft 16a, and the lower roller 2b, which the upper roller 2a is in pressure contact with, has a drum shape as shown in the figure.
The upper roller 2a is in pressure contact with the center portion.

The support shaft 10 on which the upper roller 5a of the pair of registration rollers 5 is mounted is biased by a pressure spring 41 via a pair of bearings 40, and due to the biasing force of the pressure spring 41, The upper roller 5a is in pressure contact with the lower roller 5b.

The clamping force of the sheet material P by the upper roller 5a is set to be larger than the clamping force by the slip roller pair 2 on the upstream side. Further, the slip roller pair 2 is driven by a pulse motor 62 controlled by a control section 60. At the downstream end of the guide plate pair 3, a flag 4 is rotatably supported by a support shaft 42.
2 and a photosensor 43 which is turned on and off by this flag 42 are disposed, and the pair of guide plates detects the sheet material P moving inside 3. Further, near one side of the pair of guide plates 3, a photosensor 45 is arranged to detect the paper edge of the sheet material P whose lateral displacement position is to be adjusted.

Next, the operation of the sheet material conveying device configured as described above will be explained with reference to the flowchart shown in FIG.

First, with the start of conveyance of the sheet material P, the slip roller pair 2 begins to rotate (S1). Next, a flag 42 indicates that the sheet material P has been fed through the guide plate pair 3.
It is detected by the light shielding of the photosensor 43 due to the rotation of (S2). After the leading edge of the sheet hits the nip portion of the registration roller pair 5, the slip roller pair 2 continues to rotate for a predetermined time t. At this time, the guide plate pair 3a,
If the distance between the rollers 3b is narrow and a gap is not created for the sheet material P to form a loop, the slip roller pair 2 will operate as a so-called slip roller (S3).

Next, the pair of registration rollers 5 begins to rotate, and the sheet material P is sent out by the pair of registration rollers 5 (S4). Thereafter, the registration roller pair 5 is moved in the axial direction by the roller pair moving means 9 (see FIG. 9), and the positioning of the sheet material P in the direction perpendicular to the feeding direction (sheet width direction) is determined (S5, 6, 7). Then, the sheet material P is sent to the photosensitive drum 1. When conveying this sheet material P, as shown in FIG. 3, since the upper roller 2a can freely move in the direction of arrow C, the sheet material P is moved in the direction of arrow A in FIG. 1 by the registration roller pair 5. According to
The upper roller 2a follows and moves in the same direction.

With the above configuration, the image forming position on the photosensitive drum 1 can be aligned with the position perpendicular to the feeding direction of the sheet material P. Further, the sheet material P is transferred to the registration roller pair 5 by the slip roller pair 2.
Since the pair of registration rollers 5 is pushed in the direction, the pair of registration rollers 5 reliably enters the nip portion of the pair of registration rollers 5, and the image position on the photosensitive drum 1 and the position in the width direction of the sheet material P (position in the direction perpendicular to the conveying direction) can be matched accurately.

Further, since the upper roller 2a can be easily moved in the direction of arrow C, the sheet material P can be moved easily in the direction of the arrow C.
The sheet material P moves easily in the direction of the arrow C in accordance with the movement of the sheet material P, and wrinkles, tears, etc. do not occur in the sheet material P when adjusting the horizontal displacement of the sheet material P. In particular, since wrinkles and the like can be prevented during the lateral shift adjustment described above without adding any special parts, it is possible to prevent an increase in cost and size of the device.

Further, in this embodiment, a case has been described in which the sheet material P is accurately positioned in the directions of the arrows A and B in FIG. 1 in the image forming apparatus. By applying the present invention to a device that reads images from a sheet material, images can be read from a more accurate position.

As shown in FIG. 3, the lower roller 2b is shaped like a drum, so after the sheet P passes through the pair of slip rollers 2, the lower roller 2b returns to the center of the upper roller 2a. Even if the next sheet P moves in either direction of the arrow A by the pair of registration rollers 5, the upper roller 2a is prevented from shifting to one side with respect to the lower roller 2b.

FIG. 4 shows another configuration of the slip roller pair 2. In FIG. In the same figure, the upper roller 2a has an end portion of 1
Pressure springs 49a each locked to a pair of locking members 50
, 49b against the lower roller 2b. When the registration roller pair 5 moves in the direction of arrow A to adjust the lateral displacement, the upper roller 2a is moved in the same direction (direction of arrow D) via the sheet P. This upper roller 2a moves against the pressure spring 49 on the opposite side to the moving direction, so after the sheet P passes the slip roller pair 2, the upper roller 2a is moved to its original position at the center of the lower roller 2b. automatically returns to. In this embodiment, the upper roller 2a can be driven by the lower roller 2b without forming the lower roller 2b into a special drum-shaped shape as shown in FIG.

Next, a second embodiment of the present invention will be explained with reference to FIG.

In this embodiment, steps (S1) to (S1) to (S1) of the embodiment shown in FIG.
Up to S3) and (S4) to (S7) are the same. Then, in (S3), the lip roller pair 2 is stopped after a predetermined time t has elapsed (S31), and then the slip roller pair 2 is driven by only the registration roller pair 5 being moved, and the slip roller pair 2 and the registration roller pair 5 are driven. sheet P between
It is possible to prevent the sheet P from sagging and to prevent the sheet P from becoming bent. In this embodiment, as in the first embodiment, when the registration roller pair 5 moves in the lateral displacement adjustment direction, the upper roller 2a of the slip roller pair 2 is driven, causing damage to the sheet P, wrinkles, etc. is prevented.

FIG. 7 shows a flowchart of a third embodiment of the invention.

In this embodiment, as in the previous embodiment, after the slip roller pair 2 is stopped (S31), the registration roller pair 5 is rotated. After that, a predetermined time t2
After the time has elapsed (S41), the slip roller pair 2 begins to rotate (S42). By doing this, the sheet P is prevented from forming a small loop between the pair of guide plates 3, and the pair of slip rollers 2 and the pair of registration rollers 5 are prevented from forming a small loop.
If t2 is determined at a timing that prevents it from following,
The load of the slip roller pair 2 via the sheet P is no longer applied to the registration roller pair 5. As a result, even if this embodiment is used in an image forming apparatus, there will be no sudden load fluctuations due to sheet feeding, so it is possible to prevent wrinkles, damage, etc. of the sheet P, and to realize a stable sheet material conveying device. can.

Furthermore, in this embodiment, (S42) is replaced by (S5
), but the same effect can be achieved even if (S42) is placed anywhere between (S41) and (S7).

[0045]

[Effects of the Invention] As explained above, according to the present invention,
When adjusting the position of lateral displacement by moving the first conveying means and the sheet material held therein in a direction perpendicular to the sheet material conveying direction, the second conveying means follows the movement of the first conveying means, and Since the rollers on the negative side of the conveying means can be driven, it is possible to adjust the horizontal displacement of the sheet material without increasing the size or cost of the device, and prevents damage or wrinkles to the sheet material during adjustment. It can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a sheet material conveying device showing an embodiment of the present invention.

FIG. 2 is a side view as well.

FIG. 3 is a perspective view of a slip roller (second conveyance means) section.

FIG. 4 is a perspective view showing another embodiment of the slip roller section.

FIG. 5 is a flowchart according to the first embodiment of the present invention.

FIG. 6 is a flowchart according to a second embodiment of the present invention.

FIG. 7 is a flowchart according to a third embodiment of the present invention.

FIG. 8 is a side view showing an example of a conventional sheet material conveying device.

FIG. 9 is a front view of a pair of registration rollers (first conveying means) and a pair of roller moving means.

FIG. 10 is a diagram showing the action when adjusting the lateral deviation of the sheet material.

[Explanation of symbols]

P Sheet material 1 Photosensitive drum 2 Second conveyance means (slip roller)
2a Upper roller 2a 2b Lower roller 2b 3 Guide plate pair 5 First conveying means (registration roller pair) 9 Roller pair moving means 16 Elastic members 49a, 49b Pressure spring 42 Flags 43, 45 Photo sensor 60
control part

Claims (4)

[Claims] 1. A first roller pair that pinches and conveys a sheet material, a second roller pair on the upstream side thereof, and a roller pair that moves the first roller pair in a direction perpendicular to the sheet material conveyance direction. In a sheet material conveying device having a moving means, at least one roller of the second roller pair,
A sheet material conveying device, characterized in that the sheet material conveying device is made movable following the movement of the sheet material due to the movement of the first pair of rollers. 2. The sheet material conveying device according to claim 1, wherein the sheet material clamping pressure of the first pair of rollers is greater than the clamping pressure of the second roller pair. 3. The movable rollers of the second roller pair return to their original positions before the sheet material passes after the sheet material passes the second roller pair.
The sheet material conveying device described. 4. The sheet material conveying device according to claim 1, wherein the movable roller of the second roller pair is narrower than the immovable roller.