JP6004775B2 - Sheet transport device - Google Patents

Description

  The present invention relates to a sheet registration correction mechanism in a sheet conveyance path of an electrophotographic copying machine or the like. In particular, the present invention relates to an image forming apparatus that prevents damage to the front end of a sheet during registration correction.

  An image reading apparatus such as a scanner includes an image reading unit that reads an image on a sheet, and a feeding mechanism that supplies the sheet to the image reading unit from a feeding tray. Further, an image forming apparatus such as a printer has an image forming unit that forms an image on a sheet, and a feeding mechanism that feeds the sheet from the feeding tray to the image forming unit.

  In such a sheet conveyance path before the image reading unit of the image reading apparatus and a sheet conveyance path before the image forming unit of the image forming apparatus, the direction of the conveyed sheet is corrected, and the sheet conveyance direction and the sheet direction are adjusted. A registration correction (skew correction) mechanism is provided that is substantially the same.

  A general registration correction mechanism includes a registration roller and a space portion (hereinafter referred to as a loop space) provided in the entire area perpendicular to the transport direction (hereinafter referred to as a thrust direction) on the transport surface, immediately upstream of the registration roller. Is provided.

  The registration roller has a driving roller surface made of a high friction material such as rubber and a driven roller surface made of a low friction material such as polyacetal resin in order to convey the sheet after registration correction.

  The conveying force of the registration roller is obtained by a rubber-paper frictional force generated when pressure is applied from a driven roller (hereinafter, pinch roller) to a driving roller by a spring or the like. This conveying force is generally 1.5 to 2.0 [kgf].

  The registration rollers are stopped when the leading edge of the sheet is introduced into the nip, and after the leading edge of the sheet reaches the nip, a predetermined distance is further fed to return the sheet to its original posture while bending the sheet in the loop space. Using the restoring force (koshi force) to try, the front end position of the sheet in the entire thrust direction is applied to the registration roller nip and aligned.

  After that, the sheet is conveyed by the registration roller in a state where the leading edge of the sheet is aligned, so that the sheet is conveyed with the direction of the sheet substantially the same as the conveyance direction downstream from the registration roller.

  Recently, however, cardboard is often used. In this case, the sheet is strong, and the leading edge penetrates through the nip, so that the resist correction capability often decreases.

  As one means for solving the problem, a method of reversing the registration roller when the leading edge of the sheet enters the registration roller nip is widely known. In this way, it is expected that the resist correction capability can be improved without penetrating the nip even for a strong sheet.

   However, in practice, before the leading edge of the sheet reaches the registration roller nip, it comes into contact with the reverse registration roller and is moved back in the upstream direction, which makes it difficult to introduce the sheet into the nip.

  As one means for solving such a problem, as disclosed in Patent Document 1, a method is often used in which a guide means is provided that is disposed at substantially the same position in the thrust direction as the registration roller and guides the sheet leading edge toward the pinch roller. It is done.

  This guide means covers the surface of the registration roller exposed from the lower conveyance guide so that the front end of the sheet does not come into contact with the low friction surface of the pinch roller. Capabilities are improved.

  As one of further solution means, as disclosed in Patent Document 2, guide means for guiding the leading edge of the sheet to the pinch roller side may be provided on both sides of the registration roller in the thrust direction. By urging the leading edge of the sheet toward the pinch roller by this guide means, the risk of contact with the registration roller is reduced.

  However, the guiding means of Patent Document 2 is designed to prevent skew by pressing a sheet against a rib provided on the conveyance path, and is not proposed for improving the introduction to the registration roller nip.

  FIG. 11 is a diagram showing a configuration of a conventional example in which guide means is provided for improving the introduction of the registration roller nip.

  The guide means 500 is provided on both sides of the registration roller 206b and guides the sheet to the pinch roller 206a.

  When the leading edge of the sheet reaches the registration roller nip portion by the guide means 500, the leading edge of the sheet undulates in the thrust direction due to the urging of the guiding means 500 toward the pinch roller 206a and the outer shape of the pinch roller 206a. become. That is, the bent portion 501 of the guide means 500 is substantially at the same position as the nip in the sheet conveying direction, and the position of the nip portion and the bent portion 501 is different in the vertical direction, so that the leading edge of the sheet has a shape 600 that waves in the thrust direction. .

  In FIG. 11A, the thick line represents the sheet P described above. FIG. 11B is a view of the state in which the leading edge of the sheet P reaches the registration roller nip to form a registration loop, as viewed from above the apparatus. The thrust direction (th direction in the figure) and the conveyance direction The state of the document edge is projected in the direction of tr in the figure by the third trigonometric method.

  As shown in the th-side projection view of FIG. 11B, the tip of the sheet P is moved toward the pinch roller 206a at the portion urged by the guide means 500, and the pinch roller 206a at the portion corresponding to the registration roller 206b. It is in a state of following the outer diameter shape.

  In such a state, the sheet P is stiff in the conveying direction due to the corrugated shape 600 from the leading edge to the upstream direction.

  Also, as shown in the tr side projection view of FIG. 11B, at the time of registration correction, the stiffness of the paper in the transport direction is folded by feeding by the upstream roller and is directed into a previously provided space (SL in the figure). While forming the loop 601, the leading edge of the sheet is sequentially abutted against the registration roller.

  FIG. 11B shows a state in which when the sheet reaches the nip 206n, the leading end of the sheet enters in a depth direction (the advance on the right side in the drawing).

  However, if there is stiffness in the conveying direction due to the corrugated shape 600, the stiffness in the conveying direction tr and the thrust direction th will conflict and smooth loop formation will not be possible, and damage to the sheet P, such as wrinkles, may occur especially in thin paper was there.

JP 2006-256798 A JP-A-7-76438

  As described above, in the conventional sheet conveying apparatus, there is a case where a smooth loop for skew correction cannot be formed in the registration roller portion that corrects the skew of the sheet.

  The present invention has been made in view of such circumstances, and is necessary for skew correction without deteriorating the introduction of the pair of rotating bodies into the nip portion in a sheet conveying apparatus that performs skew correction by the pair of rotating bodies. An object of the present invention is to provide a sheet conveying apparatus capable of reliably forming a simple loop.

In order to achieve this object, a sheet conveying apparatus according to the present invention includes a plurality of first rotating bodies arranged in a direction orthogonal to a sheet conveying direction, and a nip contacting a peripheral surface of the first rotating body. Sheet transport that transports a sheet by a pair of rotating bodies formed by a second rotating body that forms a portion and a second rotating body that has a lower frictional surface than the peripheral surface of the first rotating body In the sheet conveying apparatus capable of correcting sheet skew by abutting the leading end of the sheet against the pair of rotating bodies, the first rotating body on the upstream side in the sheet conveying direction from the nip portion. Between the first guide member disposed so as to cover the peripheral surface of the first rotating member and the plurality of first rotating members, and the leading end of the sheet conveyed to the nip portion is the second rotating member. A second guide member biased toward the The second guide member has a bent portion that is bent between an upstream end and a downstream end in the sheet conveying direction, and the upstream end is parallel to the conveyed sheet and the nip portion Is disposed closer to the first rotating body than the nip surface including the upstream end portion, the plane including the bent portion, and the nip surface is disposed at an angle smaller than 45 °, and The bent portion is disposed on the upstream side in the sheet conveying direction from the nip portion, is disposed on the second rotating body side from the nip surface, and passes through the rotation center of the second rotating body to the nip surface. The downstream end portion is disposed on the downstream side of the nip portion with respect to the sheet conveying direction with respect to the surface of the first rotating body with respect to the surface having an angle of 45 °, and the first nip surface from the nip surface. Arranged on the rotating body side, and the bent portion and the downstream side Contact with the outer diameter of the plane said second rotary body includes an end, or a plane including the bent portion and the downstream end is arranged to be positioned inside the outer diameter of the second rotary member It is characterized by.

  According to the present invention, the bent portion of the second guide member is arranged on the upstream side of the nip and on the second rotating body side of the nip surface, and the downstream side end portion is rotated downstream of the nip and on the first rotation of the nip surface. Arranged on the side of the body. For this reason, before the leading edge of the sheet reaches the nip, the bending portion can be folded in the thrust direction to eliminate damage such as vertical wrinkles. Therefore, a registration loop of a sheet necessary for skew correction can be reliably formed without deteriorating the introduction to the rotator nip in the registration correction unit using the pair of rotating bodies.

It is sectional drawing of the scanner apparatus of embodiment of this invention. It is a block diagram which shows the structure of the main drive control systems of the scanner apparatus shown in FIG. FIG. 3 is a diagram showing the configuration of the drive system of the registration correction mechanism of the scanner apparatus shown in FIG. FIG. 3A shows a state of feeding driving when the sheet is fed into the apparatus, and shows a state when the sheet is further conveyed downstream. 4 is a flowchart showing forward / reverse rotation switching control of a feeding motor that drives the registration correction mechanism of FIG. 3. It is a figure which shows the structure of the registration correction mechanism of the scanner apparatus shown in FIG. 1, and its peripheral part. FIG. 6 is a cross-sectional view illustrating configurations of a pinch roller, a registration roller, and a first guide member of the registration correction mechanism illustrated in FIG. 5. It is a figure which shows the detailed structure of the 2nd guide member of the registration correction mechanism shown in FIG. FIG. 7A is a perspective view, and FIG. 7B is a side view. It is a figure explaining in detail the position where the 2nd guide member is arranged. 8A is a side view, and FIG. 8B is an enlarged view of the vicinity of the nip portion. In an embodiment of the present invention, it is a figure showing signs that a sheet is conveyed to a registration mechanism part. FIG. 9A is a diagram illustrating a state in which the leading end portion of the sheet has been transported to just before the bent portion of the second guide member of the registration mechanism portion, and FIG. 9B illustrates the leading end portion of the sheet. It is a figure which shows a mode that it has conveyed to the registration roller nip. It is a figure which shows the structure of the registration mechanism part of the scanner apparatus of other embodiment of this invention. It is a figure which shows the structure of the registration correction mechanism of the conventional scanner apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
(Overall configuration of scanner device)
FIG. 1 is a cross-sectional view showing a configuration of a scanner device for reading a sheet image according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the main drive control system of the scanner apparatus shown in FIG.

  When the sheet bundle is set on the document tray 202, the document detection presence / absence sensor S5 determines that there is a document. When the start of the reading operation is input by the user, the separation motor M1 is driven to drive the pickup roller 203 and the separation roller 205, and the sheet bundle is separated one by one by the separation pad 204 and conveyed into the apparatus. The The separation sensor S1 detects that the sheet is positioned on the separation roller 205.

  When the leading edge of the sheet reaches the registration sensor S2, it is fed by a separation roller 205 by a predetermined distance therefrom, and the loop space upstream of the pinch roller 206a (second rotating body) and the registration roller 206b (first rotating body). A loop is formed by SL. The leading edge of the sheet abuts against a rotating body pair constituted by a pinch roller 206a and a registration roller 206b so that the axis of the rotating body pair and the sheet leading edge are parallel to each other. Corrected).

  Thereafter, the leading edge of the sheet is pulled out by the pinch roller 206a and the registration roller 206b, and reaches the read sensor S3 through the conveyance roller 208.

  When the leading edge of the sheet reaches the read sensor S3, a reading element such as a CCD is driven, and when the leading edge of the sheet reaches the reading position 213 facing the platen roller 211 via the first lead roller 209, the image reading unit 214 is read. The image reading operation starts.

  The sheet on which the image has been read is discharged to the discharge tray 218 through the second lead roller 215, the third lead roller 216, and the discharge rollers 217a and 217b.

  Meanwhile, when the trailing edge of the sheet passes the separation sensor S1, the presence or absence of a document on the document tray 202 is detected, and if it is determined that there is a document, the next feeding operation is started.

  If it is determined that there is no document, the driving of the CCD or the like is stopped, the feeding operation is stopped, and the feeding clutch CL is energized so that torque can be transmitted. Then, the separation motor M1 is rotated in the reverse direction (direction in which the registration roller 206b is rotated in the downstream direction), and the pickup roller 203 is lifted to the initial standby position (position shown in FIG. 1).

  As shown in FIG. 2, the sensors, the separation motor M1, and the feeding clutch CL are input to the control unit 800. The control unit 800 includes a ROM 803 that stores a program, a RAM 802 that is used as a work area, and a CPU 801 that executes the program.

  FIG. 3 is a diagram showing the configuration of the drive system of the registration correction mechanism of the scanner apparatus shown in FIG. FIG. 3 is a view of the scanner device as viewed from above, and the arrows indicate the movement direction or the rotation direction that can be recognized when viewed from above.

  The registration roller 206 b is driven by the same drive source as the pickup roller 203 and the separation roller 205.

  FIG. 3A shows a state of feeding driving when the pickup roller 203 and the separation roller 205 feed the sheet into the apparatus.

  The pulley P1 of the first stage of the separation motor M1 rotates in the direction of the arrow shown in the figure, and the registration roller 206b moves in the direction of the arrow shown in the figure, that is, the sheet conveyance direction by feeding driving by the pulley gear PZ2 that rotates in the same direction as the registration roller shaft 206s. Rotate in the opposite direction.

  FIG. 3B shows a state in which the sheet is further conveyed downstream by the registration roller 206b after completion of the contact of the leading edge of the sheet to the registration roller 206b and the registration correction by the feeding drive.

  The pulley P1 at the first stage of the separation motor M1 rotates in the opposite direction to that in FIG. 3A, and the registration roller 206b rotates in the direction of the arrow shown in the drawing, that is, the sheet by the pulley gear PZ2 that rotates in the same direction as the registration roller shaft 206s. Rotate to transport downstream.

  At this time, in FIG. 3A, the gear Z4 that has received drive transmission from the pulley gear PZ2 and has been relaying the feed drive includes a feed clutch CL that is a one-way clutch on the inner diameter side. In the rotation direction of (b), it is idled and the drive is cut off. Further, the pickup roller 203 and the separation roller 205 are idled following the sheet conveyed downstream by the registration roller 206b.

  Switching of driving shown in FIGS. 3A and 3B, that is, switching of forward / reverse rotation of the separation motor M1 is performed depending on whether or not the leading edge of the sheet of the registration sensor S2 is detected.

  FIG. 4 is a flowchart showing the forward / reverse rotation switching control of the separation motor M1.

  When the feeding starts (step S100), the separation motor M1 is driven in the direction shown in FIG. 3A (step S101). When the registration sensor S2 detects the arrival of the leading edge of the sheet (step S102), the separation motor M1 is driven by a predetermined distance (step S103), and then the registration roller 206b is rotated in the direction shown in FIG. Thus, the separation motor M1 rotates (step S104).

  When the sheet passes and the registration sensor S2 is turned off, the document detection presence / absence sensor S5 determines whether or not there is a sheet on the document tray 202 (step S106). If there is a sheet, the feeding operation by the pickup roller 203 is repeated (step S100), and if there is no sheet, the feeding operation is terminated (step S107).

  The registration sensor S2 detects the arrival of the leading edge of the sheet and then feeds the sheet further in the direction of the registration roller 206b by a feeding drive by a predetermined distance. It is rotating in the opposite direction.

(Configuration of resist mechanism)
FIG. 5 shows the configuration of the registration correction mechanism and its peripheral part according to this embodiment.

In FIG. 5, a unidirectional arrow indicates the conveyance direction tr, and a double arrow indicates a thrust direction th (a direction perpendicular to the conveyance direction on the conveyance direction surface). A plurality of 206b are arranged in the thrust direction (direction perpendicular to the sheet conveying direction). The surface of the peripheral surface of the registration roller 206b is made of a material having a relatively high friction coefficient such as silicon or urethane. That is, the peripheral surface of the pinch roller 206a has a lower friction than that of the registration roller 206b.

  The registration sensor S2 is adjacent to the center of the registration roller 206b in the thrust direction, and is arranged so that the front end of the sheet can be detected almost simultaneously with the arrival of the front end of the sheet at the registration roller 206b.

(Configuration of first guide member)
The arrangement of the first guide member 4 in the thrust direction th corresponds to each registration roller 206b. The first guide member 4 is a thin plate-like guide portion that is fixed at the upstream end in the transport direction to the transport lower guide 302 and is cantilevered from the end to the downstream side, and is flexible. Have sex.

  FIG. 6 is a cross-sectional view of the pinch roller 206a, the registration roller 206b, and the first guide member 4.

  Most of the surface of the registration roller 206 b exposed from the lower conveyance guide 302 is covered with the first guide member 4. For this reason, the possibility that the leading edge of the sheet contacts the surface of the registration roller 206b can be limited between the leading edge 4e of the first guide member 4 and the nip 206n of the registration roller 206b.

  The arrangement of the front end 4e of the first guide member 4 in the transport direction tr can reduce the possibility that the front end of the sheet comes into contact with the surface of the registration roller 206b as close as possible to the nip 206n. However, if they are too close together, the leading edge 4e of the first guide member 4 prevents the leading edge of the sheet from entering the nip 206n.

In the case of cardboard (basis weight of 100 [g / m ² ] or more), the first guide member 4 is pressed by the cardboard by friction when the cardboard is transported in the downstream direction after forming the loop. There is a risk of being transported through the nip.

  Therefore, the position of the front end 4e of the first guide member 4 in the transport direction tr is set approximately 2.5 to 3 [mm] upstream from the nip 206n.

  The position of the front end 4e of the first guide member 4 in the direction perpendicular to the conveyance surface is set to the pinch roller 206a side from substantially the same position as that of the nip 206n.

  However, if the front end 4e of the first guide member 4 is excessively moved to the pinch roller 206a side, the distance from the front end 4e of the first guide member 4 to the nip 206n increases accordingly. As a result, the possibility that the leading edge of the sheet contacts the surface of the registration roller 206b increases.

  Therefore, ideally, the same position as that of the nip 206n is appropriate, but the guide to the nip 206n is possible even if it is closer to the pinch roller 206a by 0.5 to 1 [mm].

The leading edge of the sheet freely moves from the leading edge 4e of the first guide member 4 to the nip 206n. However, if the distance between the nip 206n and 0.5 to 1 [mm] is satisfied, the sheet is almost bent until it comes into contact with the surface of the registration roller 206b at a large basis weight (52 [g / m ² ] or more). Absent.

  Thereby, after passing the front end 4e of the first guide member 4, it is possible to enter the nip 206n while bringing the front end of the sheet into contact with the pinch roller 206a.

  An upper conveyance guide 301 is provided above the lower conveyance guide 302 with a predetermined interval through which the sheet passes.

(Configuration of second guide member)
For thin paper (basis weight of 52 [g / m ² ] or less) or a sheet with a folded front end (particularly, when folded to the registration roller 206b side, hereinafter referred to as a bottom folded paper), the leading edge of the sheet up to the nip 206n In some cases, the first guide member 4 alone is not sufficient for guidance. That is, in the gap from the front end 4e of the first guide member 4 to the nip 206n, the front end of the sheet is locally folded by the reversing registration roller 206b with the front end 4e of the first guide member 4 as a fulcrum. There is.

  Since the leading edge of the sheet is locally folded in this way, the contact with the nip 206n varies for each of the rollers arranged in the thrust direction, and the registration correction is deteriorated.

  The second guide member 5 is disposed on both sides in the thrust direction of the registration roller 206b in order to perform the registration correction function even for thin paper or the leading edge folded paper, and the leading edge of the sheet is the leading edge 4e of the first guide member 4. Even after passing, the pinch roller 206a is urged. The second guide member 5 is disposed between the registration rollers 206b.

  FIG. 7 is a diagram showing a detailed configuration of the second guide member 5. FIG. 7A is a perspective view, and FIG. 7B is a side view.

  As shown in FIG. 7A, the second guide member 5 includes a PET sheet 51 made of a resin material of about 0.15 [mm] and an SUS sheet 52 of about 0.1 [mm]. This is because the portion exposed on the sheet passing surface is always exposed to strong wear by passing the sheet, and the portion exposed on the sheet passing surface is made of the second guide member 5 by a sheet of metal material such as SUS having excellent wear resistance. It is for protecting.

  As shown in FIG. 7 (b), the PET sheet 51 and the SUS sheet 52 are made of the same component by a double-sided tape or the like, but have a non-adhesive part for a certain length Lt, and this part is separated. Has been. In this portion, the PET sheet 51 can be bent, and the second guide member 5 can be moved up and down in a direction perpendicular to the transport surface by the elasticity of the PET sheet 51. Here, the position of the SUS sheet when the second guide member 5 is bent downward is indicated by 52 '.

  That is, the predetermined portion including the upstream end 52r of the second guide member 5 is made of a resin material having elasticity. A portion from the predetermined portion of the second guide member 5 to the bent portion 52m and the downstream end portion 52e, which is in contact with the sheet when the sheet is conveyed, is made of a metal material.

  Further, the upstream end portion in the transport direction of the PET sheet 51 constituting the second guide member 5 is attached to the lower transport guide 302 by the double-sided tape 53. The SUS sheet 52 bent at the bent portion 52m and having the downstream end 52e as a free end is attached to the PET sheet 51 with the double-sided tape 53 as described above at the upstream portion. The lower conveyance guide 302 is a member that is directly supported by the registration roller shaft 206s by fitting with the registration roller shaft 206s.

  In this way, the second guide member 5 is attached to the lower conveyance guide 302. Since the lower conveyance guide 302 is supported by the registration roller shaft 206s, the accuracy of the arrangement of the second guide member 5 with respect to the registration roller 206b of the second guide member 5 can be improved.

  The width of the PET sheet 51 is about 6 to 7 [mm], and a total of six places are arranged on both sides of the three registration rollers 206b arranged in the thrust direction.

(Elastic force of the second guide member)
The second guide member 5 has elasticity so that it can swing in a direction perpendicular to the sheet conveyance surface.

  The elastic force of the second guide member 5 is stronger than the stiffness of the thinnest paper in the specification of the scanner device having the same width, and is lower than the stiffness of the full width of the thickest paper (the total number of second guide members) in the specification. It is set to be.

  The reason for this is as follows. That is, since the leading edge of the thin paper tends to have a wave shape in the direction perpendicular to the conveyance surface, it is necessary to urge the pinch roller 206a side so as not to contact the surface of the registration roller 206b. Also, with thick paper, the leading edge is not likely to have a wavy shape, and the elastic force that pushes the second guide member 5 toward the registration roller 206b becomes an obstacle, and the leading edge does not enter the nip 206n. Is to prevent.

(Arrangement of the second guide member in the thrust direction)
The second guide member 5 has a “h” shape bent so as to protrude toward the pinch roller 206a at the bent portion 52m, and is disposed on both sides of the registration roller 206b. Each SUS sheet 52 is disposed about 8 to 10 mm away from the registration roller 206b in the thrust direction.

  When the distance between the registration roller 206b and the SUS sheet 52 is smaller than 8 [mm], the force for sandwiching the sheet between the SUS sheet 52 and the pinch roller 206a on both sides becomes strong. For this reason, in the thick paper in which the leading end is not likely to be corrugated, the strength of the clamping force becomes an obstacle, and the nip 206n cannot be entered.

(Position of upstream end of second guide member)
FIG. 8 is a diagram for explaining in detail the position where the second guide member 5 is arranged. 8A is a side view, and FIG. 8B is an enlarged view of the vicinity of the nip portion.

  The upstream end 52r of the second guide member 5 is closer to the registration roller 206b than the nip 206n in the direction perpendicular to the conveyance surface, and the plane angle θrm connecting the upstream end 52r and the bent portion 52m is relative to the conveyance direction. And 45 ° or less.

  That is, the upstream end 52r is arranged in parallel to the conveyed sheet and closer to the registration roller 206b than the nip surface including the nip 206n, and the nip surface is formed by a plane including the upstream end 52r and the bent portion 52m. It arrange | positions so that an angle may become smaller than 45 degrees.

  By arranging the upstream end portion 52r in this way, the contact angle at the moment when the leading end of the sheet contacts the second guide member 5 becomes 45 ° or less, and the second second can be smoothly performed without bending the sheet. The surface of the guide member 5 can be moved.

(Position of the bent portion of the second guide member)
The position of the bent portion 52m of the second guide member 5 in the direction perpendicular to the conveyance surface is positioned closer to the pinch roller 206a than the height Sn of the nip 206n.

  Further, the position of the bent portion 52m in the transport direction is located upstream of the nip 206n in the transport direction, and further downstream of the straight line L45 that passes through the center of the pinch roller 206a and falls 45 ° to the upstream side of the transport direction.

  That is, the bent portion 52m is disposed on the upstream side in the sheet conveyance direction from the nip 206n, is disposed on the pinch roller 206a side from the nip surface, and passes through the rotation center of the pinch roller 206a from a surface having an angle of 45 ° with respect to the nip surface. Is also arranged on the registration roller 206b side.

  By arranging the bent portion 52m of the second guide member 5 in this way, the leading edge of the sheet after passing through the bent portion 52m can be reliably fed toward the pinch roller 206a and is in contact with the pinch roller 206a. The contact can be made at a contact angle of 45 ° or less.

  Further, by sandwiching the leading end of the document with the upstream surface of the pinch roller 206a and the second guide member 5 (the surface between the bent portion 52m and the upstream end portion 52r), the document roller 206b is separated from the registration roller 206b. The leading edge position of the document can be stabilized.

  As a result, the leading edge of the sheet can smoothly move toward the nip 206n when contacting the surface of the pinch roller 206a, and is guided to the nip without contacting the registration roller 206b.

(Position of downstream end of second guide member)
The downstream end portion 52e of the second guide member 5 is disposed closer to the registration roller 206b in the direction perpendicular to the conveyance surface than the bent portion 52m, and is disposed downstream of the nip 206n in the conveyance direction.

  Further, a part of the plane between the bent part 52m and the downstream end part 52e is positioned so as to enter the inner side with respect to the outer diameter shape of the pinch roller 206a (FIG. 8B).

  That is, the downstream end portion 52e is disposed downstream of the nip 206n in the sheet conveying direction, and is disposed on the registration roller 206b side of the nip surface. Further, the plane including the bent portion 52m and the downstream end portion 52e is disposed so as to be substantially the same or inside the outer diameter of the pinch roller 206a.

  By arranging the downstream end portion 52e in this way, it occurs when the leading end of the sheet is positioned on the upstream plane (the plane between the upstream end portion 52r and the bent portion 52m) of the second guide member 5. The bending parallel to the conveyance direction of the leading edge of the sheet is eliminated by breaking the stiffness in the thrust direction by the bending portion 52m. And it becomes easy to bend along the loop space by which the sheet | seat was arrange | positioned upstream.

  FIG. 9 is a diagram illustrating a state in which the sheet is conveyed to the registration mechanism unit. FIG. 9A is a diagram illustrating a state in which the leading end portion of the sheet has been conveyed to just before the bent portion 52m of the second guide member 5 of the registration mechanism portion. FIG. 9B is a diagram illustrating a state in which the leading end portion of the sheet has been conveyed to the nip 206n.

  As shown in these drawings, the bending 700 parallel to the sheet conveyance direction that occurs before passing through the bent portion 52m is eliminated by breaking the stiffness in the thrust direction by the bent portion 52m, and is perpendicular to the sheet conveying direction. A small deflection 701 in a certain direction occurs. That is, the stiffness in the transport direction is eliminated by a plurality of bent portions 52m provided in the thrust direction pushing up the sheet from the bottom to the top.

  As a result, the stiffness in the conveyance direction of the leading end of the sheet can be reduced and guided to the nip 206n, and a resist loop can be easily formed.

  Further, when the leading edge of the sheet is positioned on the downstream plane of the second guide member 5, the leading edge of the sheet is attached in a direction substantially perpendicular to the downstream plane of the second guide member 5 by the elastic force of the PET sheet 51. Be forced.

  As a result, as shown by the arrow in FIG. 8B, the leading end of the sheet is stably urged by the pinch roller 206a, and the direction of the urging force does not conflict with the conveying direction, so the nip 206n can be smoothly smoothed. Can enter.

  Further, until the leading edge of the sheet reaches the nip 206n, the sheet is sandwiched between the pinch roller 206a and the downstream plane of the second guide member 5 to stabilize the position of the leading edge of the sheet. For this reason, it is possible to reduce the risk of contact with the resist roller 206b rotating in reverse.

  Further, the corrugated shape in the thrust direction generated at the leading edge of the sheet is generated by the overlap between the downstream side plane and the outer diameter of the pinch roller 206a after being bent in the thrust direction at the bent portion 52m. However, the length of the stiffness in the transport direction (illustrated by Lr in FIG. 9B) is smaller than the conventional one. That is, in the present embodiment, the bent portion 52m pushes up the sheet immediately before the pinch roller 206a, and the stiffness length Lr in the transport direction is smaller than in the conventional configuration without such an action.

  Therefore, it is possible to reach the nip 206n while the wave shape in the thrust direction generated at the front end of the sheet remains relatively light.

  By configuring the first guide member 4 and the second guide member 5 as described above, it is possible to facilitate the formation of a registration loop during registration correction without deteriorating the introduction to the registration roller nip. It becomes possible.

Second Embodiment
The first embodiment is a case where the arrangement space for the second guide member is extremely limited. This embodiment is a case where there is a margin in the arrangement space of the second guide member.

  FIG. 10 is a diagram showing a configuration of a registration mechanism of a scanner device according to another embodiment of the present invention. Since other parts are the same as those in the first embodiment, description thereof is omitted.

  As shown in the drawing, the upstream end 152r, the bent portion 152m, and the downstream end 152e of the second guide member 150 have a built-in link mechanism, and the leading end of the sheet passes through the bent portion 152m. Thus, the mechanism is more carefully biased toward the pinch roller 206a.

  The second guide member 150 may be a low-sliding resin part such as polyacetal that can be molded into an arbitrary shape.

  An upstream end 152r of the upstream sheet member 152p (first rotating member) is rotatably supported by the lower conveyance guide 302. The downstream sheet member 152q (second rotating member) is rotatably supported by the upstream sheet member 152p at the bent portion 152m. Furthermore, the downstream end 152e of the downstream sheet 152 member q is slidably supported by a guide member 156 (movement restricting guide member) having a slide hole shape that restricts the downstream end 152e to a predetermined movement range. .

  The arrangement of the upstream end 152r, the bent portion 152m, and the downstream end 152e is the same as that in the first embodiment, and thus a duplicate description is omitted.

  In this embodiment, the urging force of the second guide member 150 is obtained by the compression spring 155 (the urging member) disposed on the back side of the sheet passing surface of the upstream sheet member 152p.

  The strength of the elastic force of the compression spring 155 is the same as the setting of the elastic force by the PET sheet 51 of the first embodiment. In the thin paper, each of the second guide members 150 does not swing, and in the thick paper, the thrust direction The total number of the second guide members 150 arranged in (1) is set to a pressure at which the second guide member 150 can be swung by paper stiffness.

  As the leading end of the cardboard sheet enters the nip 206n, the second guide member 150 swings to the position indicated by the dotted line in FIG. 10, and the downstream end 152e follows the guide member 156 having a predetermined slide hole shape. Move.

  As a result, it is possible to maintain a positional relationship such that the downstream plane is always in contact with the outer diameter surface (outer periphery) of the pinch roller 206a. For this reason, the leading edge of the sheet can reach the nip 206n without generating a slight leading edge wavy shape in the thrust direction and without contacting the registration roller 206b.

DESCRIPTION OF SYMBOLS 4 ... 1st guide member 5 ... 2nd guide member 51 ... PET sheet 52 ... SUS sheet 52e ... Downstream side edge part 52m ... Bending part 52r ... Upstream side edge part 152e ... Downstream side edge part 152m ... Bending part 152r ... Upstream end 152p ... Upstream sheet member 152q ... Downstream sheet member 156 ... Guide member 206 ... Registration roller pair 206a ... Pinch roller 206b ... Registration roller 302 ... Conveying lower guide S2 ... Registration sensor

Claims (6)

A plurality of first rotating bodies arranged in a direction orthogonal to a sheet conveying direction, and a second rotating body that abuts on a peripheral surface of the first rotating body to form a nip portion; A sheet conveying apparatus that conveys a sheet by a pair of rotating bodies constituted by a second rotating body having a peripheral surface having a lower friction than the peripheral surface of the rotating body, wherein the leading end of the sheet is placed on the rotating body pair In the sheet conveying device that enables skew correction of the sheet by abutting,
A first guide member disposed so as to cover a peripheral surface of the first rotating body on the upstream side in the sheet conveying direction from the nip portion;
A second guide member disposed between the plurality of first rotating bodies and urging the front end of the sheet conveyed to the nip portion toward the second rotating body;
The second guide member is
Having a bent portion bent between an upstream end and a downstream end in the sheet conveying direction;
The upstream end is disposed on the first rotating body side of the nip surface parallel to the conveyed sheet and including the nip portion, and includes a plane including the upstream end and the bent portion, and the nip. It is arranged so that the angle formed by the surface is smaller than 45 °,
The bent portion is disposed on the upstream side of the nip portion in the sheet conveying direction, is disposed on the second rotating body side with respect to the nip surface, and passes through the rotation center of the second rotating body. With respect to the surface of the first rotating body with respect to a surface at an angle of 45 °,
The downstream end is disposed on the downstream side of the nip portion in the sheet conveying direction, is disposed on the first rotating body side with respect to the nip surface, and includes the bent portion and the downstream end. The plane is in contact with the outer diameter of the second rotating body , or the plane including the bent portion and the downstream end is positioned so as to be located inside the outer diameter of the second rotating body. A sheet conveying apparatus that is characterized. A plurality of first rotating bodies arranged in a direction orthogonal to a sheet conveying direction, and a second rotating body that abuts on a peripheral surface of the first rotating body to form a nip portion; A sheet conveying apparatus that conveys a sheet by a pair of rotating bodies constituted by a second rotating body having a peripheral surface having a lower friction than the peripheral surface of the rotating body, wherein the leading end of the sheet is placed on the rotating body pair In the sheet conveying device that enables skew correction of the sheet by abutting,
A first guide member disposed so as to cover a peripheral surface of the first rotating body on the upstream side in the sheet conveying direction from the nip portion;
A second guide member disposed between the plurality of first rotating bodies and urging the front end of the sheet conveyed to the nip portion toward the second rotating body;
The second guide member is
Having a bent portion bent between an upstream end and a downstream end in the sheet conveying direction;
The arrangement of the second guide member in a state where the second guide member does not contact the sheet,
The upstream end is disposed on the first rotating body side of the nip surface parallel to the conveyed sheet and including the nip portion, and includes a plane including the upstream end and the bent portion, and the nip. It is arranged so that the angle formed by the surface is smaller than 45 °,
The bent portion is disposed on the upstream side of the nip portion in the sheet conveying direction, is disposed on the second rotating body side with respect to the nip surface, and passes through the rotation center of the second rotating body. With respect to the surface of the first rotating body with respect to a surface at an angle of 45 °,
The downstream end is disposed on the downstream side of the nip portion in the sheet conveying direction, is disposed on the first rotating body side with respect to the nip surface, and includes the bent portion and the downstream end. A plane is in contact with the outer diameter of the second rotating body, or a plane including the bent portion and the downstream end is positioned inside the outer diameter of the second rotating body,
The second guide member has an elastic force capable of swinging in a direction perpendicular to the sheet conveyance surface, and the elastic force is used for the sheet conveyance device in each of the second guide members. In the total number of the second guide members that are stronger than the elastic force of the sheet having the same width as the second guide member and are perpendicular to the sheet conveyance direction, A sheet conveying apparatus characterized by being weaker than the elastic force of the thickest sheet used in the conveying apparatus.   The predetermined portion including the upstream end portion of the second guide member is made of an elastic resin material, and the portion of the second guide member that contacts the conveyed sheet is made of a metal material. The sheet conveying apparatus according to claim 1 or 2, wherein A plurality of first rotating bodies arranged in a direction orthogonal to a sheet conveying direction, and a second rotating body that abuts on a peripheral surface of the first rotating body to form a nip portion; A sheet conveying apparatus that conveys a sheet by a pair of rotating bodies constituted by a second rotating body having a peripheral surface having a lower friction than the peripheral surface of the rotating body, wherein the leading end of the sheet is placed on the rotating body pair In the sheet conveying device that enables skew correction of the sheet by abutting,
A first guide member disposed so as to cover a peripheral surface of the first rotating body on the upstream side in the sheet conveying direction from the nip portion;
A second guide member disposed between the plurality of first rotating bodies and urging the front end of the sheet conveyed to the nip portion toward the second rotating body;
The second guide member is
Having a bent portion bent between an upstream end and a downstream end in the sheet conveying direction;
The arrangement of the second guide member in a state where the second guide member does not contact the sheet,
The upstream end is disposed on the first rotating body side of the nip surface parallel to the conveyed sheet and including the nip portion, and includes a plane including the upstream end and the bent portion, and the nip. It is arranged so that the angle formed by the surface is smaller than 45 °,
The bent portion is disposed on the upstream side of the nip portion in the sheet conveying direction, is disposed on the second rotating body side with respect to the nip surface, and passes through the rotation center of the second rotating body. With respect to the surface of the first rotating body with respect to a surface at an angle of 45 °,
The downstream end is disposed on the downstream side of the nip portion in the sheet conveying direction, is disposed on the first rotating body side with respect to the nip surface, and includes the bent portion and the downstream end. A plane is in contact with the outer diameter of the second rotating body, or a plane including the bent portion and the downstream end is positioned inside the outer diameter of the second rotating body,
The second guide member is supported so as to be rotatable about the upstream end, and is configured to rotate from the upstream end to the bent portion. A second rotating member that is movably supported and configures from the bent portion to the downstream side;
The sheet conveying device further includes:
A movement restriction guide member for restricting the downstream end to a predetermined movement range;
A biasing member that biases the second guide member;
When the sheet is conveyed, the plane including the surface of the second rotating member on the side of the second rotating body moves so as to be in contact with the outer periphery of the second rotating body. Sheet transport device.   In each of the second guide members, the urging force of the urging member is stronger than the elastic force of the thinnest sheet used in the sheet conveying device and having the same width as the second guide member, The total number of the second guide members arranged perpendicular to the sheet conveying direction is weaker than the elastic force of the thickest sheet used in the sheet conveying apparatus. The sheet conveying apparatus according to the description.   6. The first rotating body according to claim 1, wherein the first rotating body rotates in a direction opposite to a conveyance direction of the sheet until a leading end of the sheet reaches the nip portion. The sheet conveying apparatus according to item.

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