JPH04179660A - Paper attitude correcting device - Google Patents

Abstract

PURPOSE:To surely correct an attitude of paper, even when a burr and a fold are provided in a point end angular part of the paper, by providing a pair of feed rollers far holding the paper conveyed, pair of resist rollers of waiting for the paper deflected and a control unit for controlling rotation. CONSTITUTION:Paper 3 is fed to a left side from a right side by feed rollers 1, rotated driven by an A motor 8, and guided toward a contact part of resist rollers 5, 6 by a lower guide plate 2, deflection guide plate 2A and an upper guide plate 4. By preventing the resist rollers 5, 6 from coming into contact with a part where a burr or the like of the paper 3 is provided, right/left position displacements in a point end of the paper 3 can be eliminated. As a result, when the resist rollers 5, 6 are rotated reversely to a paper conveying rotational direction, the point end of the diagonally conveyed paper 3 is placed in parallel to a contact line with the resist rollers 5, 6, so that an attitude of the paper 3 can be straight corrected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention corrects the posture of paper that is fed one by one, such as cut paper, so that the leading edge line is perpendicular to the conveyance direction. The present invention relates to a paper posture correction device.

[Conventional technology]

Conventionally, a method/apparatus for correcting the posture of a cut sheet used in a printer etc., as described in Japanese Utility Model Application Publication No. 63-42648, involves bringing the sheet into contact with a registration roller (standby roller). There is a known device that corrects the skew of paper by deflecting it by a certain amount.

Furthermore, Japanese Patent Application Laid-Open No. 144036/1984 discloses a technique in which a paper leading edge positioning member is provided just before the registration roller, and the leading edge of the paper is brought into contact with this member to deflect the paper by a certain amount to correct the skew of the paper. are doing.

[Problem to be solved by the invention]

In the technique described in Japanese Utility Model Application Publication No. 63-42648, a sheet of paper enters a pair of registration rollers obliquely, and when the paper stops, the leading edge of the paper is pinched by a pair of registration rollers due to the force of the paper's entry.

For this reason, even if you try to apply force to the paper in the transport direction with the feed roller and make use of the bending rigidity of the paper to align the leading edge of the paper straight with the registration roller pair, the leading edge of the paper will be restrained by the registration rollers. Therefore, it was impossible to correct the skew.

In particular, the amount of skew correction varied depending on the paper type (paper thickness, size, etc.). Furthermore, there is a problem in that if the leading edge corner of the paper is curled or folded, the skew of the paper cannot be corrected.

SUMMARY OF THE INVENTION An object of the present invention is to provide a paper posture correction device that can reliably correct the paper posture even if the leading edge corner of the paper is curled or folded.

[Means to solve the problem]

In order to achieve the above object, the paper posture correcting device of the present invention has a pair of feed rollers that nip and convey paper, and the leading edge of the paper conveyed by the feed rollers, and waits for the paper to bend. A pair of registration rollers and a control device for controlling rotation of the feed roller and the registration roller are provided, and the sheet is fed by the feed roller and the registration roller by correcting the posture of the sheet using bending rigidity due to the bending of the sheet. In the paper posture correction device, the registration roller provides a space in a portion corresponding to both ends of the paper, and the control device rotates the registration roller by a certain amount in the opposite direction to the transport rotation direction after the paper is deflected. It is characterized by

The registration roller preferably has a roller length equal to the width of the paper excluding both ends, and
In order to handle paper of multiple sizes, the registration roller should have a maximum roller length that is equal to the width of the paper with the field, excluding both edges, and a length that is longer than the width of the paper with the maximum width, excluding both edges of paper of other sizes. It is preferable to provide grooves in opposing parts.

Further, in order to achieve the above object, another paper posture correcting device of the present invention has a pair of feed rollers that sandwich and transport paper, and the leading edge of the paper transported by the feed rollers to contact each other to prevent the paper from bending. a pair of registration rollers waiting for the rotation of the feed roller and the registration roller, and a control device that controls the rotation of the feed roller and the registration roller. In a paper posture correction device that feeds paper, the registration roller has a roller length equal to the width of the paper excluding both ends, and the control device rotates the registration roller in a direction opposite to the transport rotation direction after the paper is deflected. The registration roller is rotated by a certain amount, and is characterized in that a pair of guides are provided close to each end of the registration roller and located above and below the paper.

In order to handle paper of multiple sizes, the registration roller should have a roller length that is equal to the width of the paper with the minimum width, excluding both ends, and the guide should move the part corresponding to both ends of each paper up and down. It's good to spread it out.

[Effect]

The paper is conveyed by the feed roller, and the feed roller continues to rotate until the leading edge of the paper contacts the registration roller and bends. As the paper bends, the leading edge of the paper is pushed into the registration roller contact portion by the bending rigidity of the paper.

From this state, the registration roller rotates a predetermined amount in the opposite direction to the paper conveyance direction, and during this time, the leading edge of the paper is released from the restraint by the registration roller, and the leading edge of the paper bends along the contact line of the registration roller. When the paper is moved by force (at this time, both edges (WJ side or one side) of the paper may turn over, have small creases, or curl (in a low temperature, low humidity environment).

If the roller is curled easily), it will not be able to enter the contact line of the registration roller, and will stop at a rear position compared to the opposite side, which is not curled or curled. By shortening the registration roller so as not to contact the leading edge of the paper to provide a space, the influence of curling of the edge of the paper is removed, and the paper moves along the contact line of the registration roller.

This movement corrects the skew of the paper.

Furthermore, in the case where the registration roller has grooves that create spaces at opposing positions on both ends of the paper, the effects of curling of the paper ends are removed and the skew of the paper is corrected in the same way as described above.

Furthermore, even if guides are provided on both sides of the registration rollers with widened areas corresponding to both edges of the paper, the widened space will eliminate the effects of curling of the edges of the paper, etc., and prevent skewed feeding of the paper. It will be corrected.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a printer to which the present invention is applied;
FIG. 2 is a configuration diagram showing a paper posture correction device according to an embodiment of the present invention. Note that FIG. 1 shows the main parts of the apparatus according to the present invention, and the illustration of conventionally known parts such as a document handling device, a document reading device, a toner application device, etc. is omitted.

This printer includes a paper feed roller (not shown) that feeds the paper 3 stored at the bottom of the device, a transport roller IA that transports the paper 3 fed by the paper feed roller, and a paper transport roller IA that transports the paper. A lower guide plate 2 and an upper guide plate 4 are arranged on the downstream side of the direction (hereinafter simply referred to as the downstream side) and guide the paper 3, and a registration roller (hereinafter referred to as a registration roller) is arranged on the downstream side of the lower guide plate 2. a transfer belt 11 which is arranged downstream of the registration rollers 5 and 6 and rotates endlessly to place and convey the paper 3; A cylindrical photoreceptor 12 is arranged so as to touch it from above, a fixing device 13 is arranged close to the downstream end of the transfer belt 11, and a fixing device 13 is arranged downstream of the fixing device 13 to transfer the paper 3 onto the device. a developing device 14 disposed close to the photoconductor 12 on the upstream side in the rotational direction of the photoconductor 12 from the point where the photoconductor 12 contacts the transfer belt 11; The cleaner 15 is disposed close to the photoreceptor 12 on the downstream side in the rotational direction of the photoreceptor 12 than the location where the transfer belt 12 contacts the transfer belt 11, and the conveyance roller IA is different from the conveyance roller IA on the upstream side of the registration rollers 5 and 6. Conveyance roller IB placed on the side
and a manual feed stand 17 arranged upstream of the conveyance roller IB.
It is equipped with

The registration rollers are composed of a pair of upper rollers 6 and lower rollers 5 that rotate while contacting each other along the generatrix of the outer peripheral surface, and the rotation axes of these upper and lower rollers 6.5 are connected to the conveyance roller IA.
, IB are arranged parallel to the rotation axis of the photoreceptor 12 and the rotation drive axis of the transfer belt 11. In addition, the conveyance roller I
A also consists of a pair of rollers that rotate while contacting each other along the outer circumferential generatrix, one of the rollers is rotationally driven by the A motor 8, and the lower roller 5 of the registration rollers is driven by the B motor 9. Rotationally driven. A pair of gears 7 that mesh with each other are attached to the upper roller 6 and the lower roller 5, and the rotational force applied to the lower roller 5 is applied to the gears 7.
It is also transmitted to the upper roller 6 via. Both the A motor 8 and the B motor 9 are connected to a control device [10]. A paper passage sensor 18 that detects the passage of paper is arranged downstream of the transport rollers IA and IB.

In the printer configured as described above, when printing is instructed, the stored paper 3 is fed to the transport roller IA by a paper feed roller (not shown), and the paper 3 is fed to the transport roller IA by a paper feed roller (not shown).
The paper is conveyed toward the registration rollers 5.6. The paper 3 conveyed toward the registration rollers 5, 6 has its posture corrected between the registration rollers 5.6 and the conveyance rollers IA, IB, and then is transferred to the transfer belt 1 by the registration rollers.
1, and the transfer belt 11 brings the paper 3 into contact with the photoreceptor l carrying the developed image on its surface while conveying the paper 3.

While the paper 3 is in contact with the photoreceptor 1, the developed image carried on the surface of the photoreceptor 1 is transferred by a transfer device (not shown).6 The paper 3, onto which the developed image has been transferred, is transferred to the fixing device 13 by the transfer belt 11. After being fed in and undergoing a fixing process, it is discharged onto the top surface of the apparatus by a discharge roller 16.

Next, the paper posture correcting device according to the present invention will be explained in detail with reference to FIG. 2 and FIG. 3 showing a cross section taken along line A-A in FIG.

In FIG. 1, the paper 3 changes its traveling direction by about 90° on the paper transport path from the transport roller IA to the registration rollers 5 and 6, but this change in the traveling direction is a feature of the present invention. Since this is not related to the essence, the following description will be based on a case where there is no change in the traveling direction of the sheet 3 from the conveyance roller to the registration roller, that is, when the sheet is flattened and conveyed. The paper posture correction device shown in FIG.
on the printer side plate (not shown) so that the rotation axes are parallel to each other and lightly touching each other.

A pair of conveyance rollers (hereinafter referred to as feed rollers) 1 arranged above and below, an A motor 8 that rotationally drives one of the feed rollers 1, and an A motor 8 that rotationally drives one of the feed rollers 1, and a A flat lower guide plate 2 disposed on a surface below the contact line, a pair of registration rollers 6.5 disposed vertically close to the downstream side of the lower guide plate 2 and lightly touching each other, and registration rollers. A pair of gears 7 that are attached to rotating shafts 5 and 6 and mesh with each other, a B motor 9 that rotationally drives the lower registration roller 6, and a B motor 9 that approaches the lower guide plate 2 as it becomes downstream of the lower guide plate 2. The upper guide plate 4, the paper passage sensor 18 provided on the exit side of the feed roller 1, and the paper passage sensor 18. A motor 8 and B
A control device 10 connected to the motor 9 and controlling the rotation of both motors is provided. A control device 10 includes a timer, a relay, etc., and serves as a means for reversing the registration rollers.

Both the lower guide plate 2 and the upper guide plate 4 are attached to a printer side plate (not shown), and a rectangular deflection guide plate 2A is provided on the upper surface of the lower guide plate 2 closer to the downstream side. The deflection guide plate 2A is arranged so that one long side (2AU) is in contact with the upper surface of the lower guide plate 2, and the other long side (2AD) slopes upward toward the downstream side. Further, the deflection guide plate 2A is arranged so that its long sides 2AU and 2AD are parallel to the feed roller 1, and the long side 2AD is sandwiched between the lower guide plate 2 and the upper guide plate 4. .

In the paper posture correction device configured as described above, the paper 3 is moved to the second
It is fed from the right side (upstream side) to the left side (downstream side) in the figure, and is guided by the lower guide plate 2, the deflection guide plate 2A, and the upper guide plate 4 toward the fi part of the registration rollers 5, 6 (7). The paper passage sensor 18 detects when the leading edge of the paper passes the registration rollers 5 and 6 as the paper leaves the feed roller 1, and outputs a detection signal to the control device w10. Control device 10
stops the rotation of the feed roller 1 after a predetermined period of time after receiving the detection signal, and then stops the rotation of the registration rollers 5 and 6.
for another predetermined period of time. Although this amount of reversal is set based on time in this embodiment, it may also be set based on the rotation angle of the registration rollers 5 and 6.

The time from when the detection signal is received to when the feed roller stops is such that the leading edge of the sheet fed by the feed roller comes into contact with the registration rollers 5 and 6 and stops, causing the sheet 3 to stop as shown in FIG. The time is set to allow a bulge (deflection) h such that the

In other words, the paper 3 is fed by the feed roller 1 in the direction of the registration rollers 5 and 6, and the leading edge of the paper 3 is guided by the lower guide plate 2, the deflection guide plate 2A, and the upper guide plate 4, and is fed toward the registration rollers 5 and 6. Abuts on the contact part. The leading edge of the paper 3 partially enters the contact portion of the registration rollers 5 and 6 due to the force of contact, and becomes sandwiched between the rollers 5 and 6. Even after the leading edge of the paper 3 comes into contact with the contact portions of the registration rollers 5 and 6, the feed roller 1 continues to rotate for a predetermined period of time, and the paper 3 continues to be fed. As the paper 3 continues to be fed even after the leading edge of the paper 3 comes into contact with the paper 3, the paper 3 is deflected between the lower guide plate 2 and the upper guide plate 4.

The control device 1o is configured to rotate the B motor 9 for driving the registration rollers forward and reverse, and when the motor is stopped, controls the excitation current so as to temporarily stop the rotation of the rotating magnetic field. As a result, 1. The B motor 9 maintains a stopped state and generates a holding torque on one rotor. Therefore, even if the leading edge of the paper 3 comes into contact with the contact portion of the registration rollers 5 and 6 and a part of the leading edge enters the contact area, the registration rollers 5 and 6 will not rotate due to the force received from the paper 3. .

Since the clamping force of the registration rollers 5 and 6 applied to the leading edge of the paper 3 varies depending on the paper type, if the paper posture correction is completed at this stage, the accuracy of the paper posture correction will vary depending on the target paper type. In addition, the leading edge of the paper 3 that is clamped cannot overcome the clamping force of the registration rollers 5 and 6 and move along the contact line of the registration rollers 5 and 6 due to the bending rigidity of the paper 3.

In this embodiment, after the paper 3 comes into contact with the registration rollers 5 and 6, the B motor 9 for driving the registration rollers is rotated in the opposite direction by a certain amount (angle), and the paper 3 held between the registration rollers 5 and 6 is rotated in the opposite direction. The leading edge of the paper 3 is sent out in the opposite direction to the conveyance direction, and the clamping force applied to the paper 3 is eliminated. As a result, the leading edge of the paper 3 becomes free and moves along the contact line of the registration rollers 5.6 due to the bending rigidity of the paper 3. By this movement, the skew of the paper 3 is corrected, and the correction of the paper posture is completed.

When the posture correction of the paper 3 is completed, the feed roller 1 and the registration rollers 5 and 6 are operated by the A motor 8 and the B motor 9, respectively.
As a result, the paper 3 starts to rotate simultaneously in the paper transport direction, and the paper 3 passes through the registration rollers 5 and 6 and is fed to the transfer section on the downstream side.

The outer peripheral surface of the registration roller 6 is formed of a smooth metal surface, which allows the leading edge of the paper 3 to move more smoothly during posture correction. On the other hand, the outer peripheral surface of the registration roller 5 is made of rubber.

FIG. 4 is an explanatory diagram showing the movement of the paper when the posture of the paper is corrected, and for the sake of explanation, shows the movement of the paper when the body length of the registration roller is longer than the width of the paper.

When the registration rollers 5 and 6 are rotated in the opposite direction to the paper conveyance rotation direction while the paper 3 is being held between the feed rollers 1, the holding force applied to the tip of the bent paper 3 is removed.

As a result, the leading edge of the paper 3 becomes free and moves along the contact line of the registration rollers 5.6 due to the bending rigidity of the paper 3 (movement A). As a result, the paper 3, which has been conveyed at an oblique angle θ, is corrected to be straight at its leading end.

Please note that when correcting your posture, the amount of deflection may decrease slightly and move A.
2), shift laterally (movement A3). As shown in FIG. 4, if the paper 3 is not curled up, it will come into contact with the registration rollers 5, 6 straight and stop, so that the sheet 3 will be moved in the conveying direction of the registration rollers 5, 6 and the feed roller 1. is sent straight to the subsequent process.

However, as shown in FIG.
or bent edges), register rollers 5 and 6.
Even if the paper 3 is reversed, the leading edge of the paper 3 cannot enter the contact portion of the registration rollers 5 and 6. As a result, the posture of the paper 3 cannot be correctly corrected, and in this case, the accuracy of the posture correction varies depending on the degree of curling of the paper 3, etc. Furthermore, if the paper 3 is conveyed straight, the paper 3 is reversely conveyed by coming into contact with the registration rollers 5 and 6.
This causes it to become slanted.

Assuming that the difference in the position of one side edge P and P2 of the paper 3 in the conveyance direction is shifted by a due to turning as shown in FIG. 6, when the width of the paper 3 is b, θ' = s
Posture correction will be performed in a state where the paper 3 is tilted by a / b.If θ' is larger than the inclination θ of the paper 3 before performing posture correction, the posture control will reverse the inclination. As a result, the inclination of the paper 3 increases.

FIG. 7 is a diagram showing an embodiment of the present invention, which solves the above-mentioned problem of curling. Registration roller 5
, 6 from coming into contact with a curled portion of the paper 3, etc., it is possible to eliminate the lateral positional deviation a at the leading edge of the paper 3 as shown in FIG. As a result, when the registration rollers 5.6 are rotated in the opposite direction to the sheet conveyance rotation direction, the leading edge of the sheet 3 that has been conveyed obliquely is moved to the registration roller 5.
Since it is parallel to the contact line of 6 degrees, the posture of the paper 3 can be straightened. FIG. 7 shows the state of interference between the rollers and the paper when the lengths of the registration rollers 5 and 6 are made shorter than the width of the paper 3.

FIG. 8 is a diagram illustrating another embodiment of the present invention, and FIG. 9 is a view taken along the line B--B in FIG. 8. The upper roller 6 of the registration rollers is composed of a center roller 6a and side rollers 6b on both sides thereof, and a space is provided between the center roller and each side roller. Similarly, the lower roller 5 is composed of a center roller 5a and side rollers 5b. Incidentally, laser printers often use several types of paper with different widths. Therefore, as shown in FIG. 7, assume that, for example, A4 cut paper is fed sometimes in the longitudinal direction and sometimes in the transverse direction. In this case, the central roller 5a.

A space between the side rollers 6a and the side rollers 5b, 6b is provided at a position corresponding to the side edge of the width of the sheet 3, and the space between the side rollers 5b, 6b is
Regarding rollers b and 6b, the lengths of the rollers are determined so that there is a space in the portion corresponding to the side edge of the paper length Q. In this way, even if the leading edge corner of the paper is curled or folded, the curled or folded portion does not come into contact with the registration rollers, so that the posture of the paper can be corrected. In this embodiment, the length and shape of the feed roller 1 are not particularly described, but it goes without saying that the feed roller 1 may have a shape that does not pinch the paper 3 when it is turned over.

10th vl is a diagram showing another embodiment of the present invention.

In this embodiment, a central roller is provided as in the embodiment shown in FIG. 8, and guides 20 are installed on both sides of the central roller. This guide 20 is plate-shaped and consists of a pair of upper and lower parts, and a gap is provided between them to allow the edge of the paper to pass through the gap to prevent the edges of the paper 3 from being pushed too hard.

FIG. 11 is a diagram showing another embodiment, in which the cross-sectional shape is different from that of the guide provided in the embodiment of FIG. 10, and a guide 21 with a rectangular cross-sectional shape is used to avoid curling up of both ends of the paper. A wide gap may be provided. Further, as shown in FIG. 12, the guide 22 may have a chevron-shaped cross-section, or the guide may be formed by arranging rods in parallel in the transport direction, as in the guide 23 shown in FIG. 13.

As described above, the paper posture correction device configured by combining registration rollers and guides can control the vertical deformation of the paper in response to the degree of deflection of the paper due to different thicknesses, that is, differences in paper rigidity. It is possible to reliably correct the posture of paper with curls, etc.

〔Effect of the invention〕

According to the present invention, in the paper posture correction device of the present invention, after the leading edge of the paper conveyed by the feed roller is brought into contact with the registration roller and bent, the registration roller is moved in the opposite direction to the conveyance rotation direction. The registration roller is controlled to rotate by a certain amount, and the registration roller or the guides provided on both sides of the registration roller are configured to have spaces in the portions corresponding to both ends of the paper, so the registration roller can be rotated in reverse. When rotated,
The gripping force of the registration rollers on the paper can be released, and even if the edges of the paper are turned up, it will not be affected.
The paper can be moved along the contact line of the registration rollers, which has the effect of reliably correcting the paper posture.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a printer to which a paper posture correction device of the present invention is applied, FIG. 2 is a configuration diagram of a paper posture correction device according to an embodiment of the present invention, and FIG. Cross section, 4th
5 is an explanatory diagram showing the movement of paper during correction by the paper posture correction device, FIG. 6 is a partial side view of FIG. 5, FIG. 7 is a diagram showing an embodiment of the present invention, and FIG. The figures show another embodiment of the present invention, FIG. 9 is a view taken along the line B-B in FIG. 8, and FIG.
Figures 1 to 13 are diagrams showing still other embodiments of the present invention. 1, LA, IB... Feed roller, 2... Lower guide plate, 3... Paper, 4... Upper guide plate, 5, 6... Registration roller, 5a, 6a... Center roller , 5b, 6
b...Side roller, 7...Gear, 8...A motor,
9...B motor, 10...Control device, 18...Paper passage sensor, 20°21.22, 23...Guide. Figure 1 11 feet' row 7
Gear 2, lower guide wL 8:A
Morph 3: Paper 9 B Morph 4
・Lower guide board 10. Medium control reward 5 I and bust tension roller lower Old: Weaving length 6: Trest and one-on roller upper Fig. 3 Fig. 4 Fig. 6 Fig. 7 Fig. 9 Fig. 11 Fig. 12 Fig. Pa Fig. 13 Tumu

Claims (1)

[Claims] 1. A pair of feed rollers that pinch and convey paper, a pair of registration rollers that abut the leading edge of the paper conveyed by the feed rollers and wait for the paper to bend, and a feed roller. and a control device for controlling the rotation of a registration roller, the paper posture correction device corrects the posture of the paper by bending rigidity force due to deflection of the paper, and feeds the paper by the feed roller and the registration roller, wherein the registration roller A paper posture correction device characterized in that the rollers are provided with spaces at portions corresponding to both ends of the paper, and the control device rotates the registration rollers by a certain amount in the opposite direction to the transport rotation direction after the paper is deflected. 2. The registration roller has the width of the paper,
2. The paper posture correcting device according to claim 1, wherein the roller has a length excluding both ends. 3. The registration roller has a roller length that is equal to the width of the paper with the largest width among the paper of multiple sizes handled, excluding both ends of the paper, and has a length that is longer than the width of the paper with the largest width among the paper of multiple sizes to be handled, and 2. A sheet posture correcting device according to claim 1, further comprising grooves provided in portions facing both ends of the sheet. 4. A pair of feed rollers that pinch and convey paper, a pair of registration rollers that bring the leading edge of the paper conveyed by the feed rollers into contact and wait for the paper to bend, and rotation of the feed roller and registration roller. In the paper posture correcting device, the paper posture correcting device includes a control device for controlling the width of the paper, corrects the posture of the paper using bending rigidity caused by deflection of the paper, and feeds the paper by the feed roller and the registration roller. It has a roller length excluding both ends,
The control device rotates the registration roller by a certain amount in the opposite direction to the transport rotation direction after the paper is deflected, and a pair of guides are provided close to each end of the registration roller and located above and below the paper, respectively. A paper posture correction device featuring: 5. The registration roller has a roller length that is equal to the width of the smallest sheet of paper of multiple sizes to be handled, excluding both ends of the paper, and the guide has a length that is equal to the width of the paper with the smallest width among the paper of multiple sizes to be handled, and the guide has a length that excludes both ends of the paper of each size. 5. The paper posture correcting device according to claim 4, wherein a portion corresponding to the width of the sheet is expanded vertically.