JP2009091139A - Sheet conveying device, and image forming device provided with sheet conveying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet conveying device capable of conveying a sheet to a predetermined position and eliminating a print skew and print deviation by a simple mechanism. <P>SOLUTION: This sheet conveying device includes: a regulating plate 103 provided at the side of a sheet conveyance passage in an image forming device or the like and changing a sheet position by the abuttment of a sheet side end thereon; and a conveying roller 110 composed of a drive roller and a driven roller arranged on and under the sheet conveyance passage, arranged along the sheet conveyance passage, constituted to be axially swung, and having an elastic member 104 pressing the conveying roller toward a predetermined axial position. The sheet conveying device adjusts the sheet position and conveys the sheet to the predetermined position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet conveying apparatus capable of conveying a sheet to a predetermined position with a simple configuration in an image forming apparatus or the like.

  In an image forming apparatus, a sheet such as a recording paper or a film passes through several steps in the middle of a conveyance path from paper supply to paper discharge. FIG. 5 is a schematic diagram illustrating a recording paper conveyance path of the double-sided image forming apparatus. The image forming apparatus includes an image forming unit 10, a paper feeding unit 20, a paper discharging unit 30, a reverse conveyance unit 40, a recording paper introduction unit 50, an intermediate stacker unit 60, and a refeeding unit 70. Have. The recording paper P passes through a paper feed path A for transporting the recording paper P to the transfer section 15 of the image forming unit 10 and a transport path B for discharging or refeeding the recorded recording paper P from the transfer section 15. A discharge path C for discharging the recording paper P on which the image has been formed to the outside of the apparatus, and a circulation reversal supply for circulating the recording paper P on which the image has been formed by the image forming unit 10 to the image forming unit 10 after being reversed. There is a paper path D.

  An image carrier (photosensitive drum) 11 is disposed in the image forming unit 10. The image carrier 11 is uniformly charged by a charger 12, and image information is stored in the image carrier 11 by an exposure unit 13. Irradiate the peripheral surface to form an electrostatic latent image. The electrostatic latent image is developed by the developing device 14 to form a toner image.

  The paper feed unit 20 is provided with at least one paper feed cassette 21. The recording paper P is taken out from the paper feed cassette 21 one by one, passes through the paper feed path A, and the leading end reaches the registration roller 28.

  The registration roller 28 is driven in synchronization with the rotation of the image carrier 11 and sends the recording paper P to the transfer unit 15. The toner image is transferred onto the recording paper P by the transfer unit 15. The recording paper P is subsequently separated from the image carrier 11 by the separator 16 and conveyed to the fixing device 18 by the belt 17 provided in the conveyance path B.

  A cleaning device 19 is disposed around the image carrier 11 to remove residual toner on the surface of the image carrier 11 after transfer. The image carrier 11 further rotates and is charged again by the charger 12 for the next image formation.

  The fixing device 18 includes a heating roller having a heater therein and a pressure roller that is driven in pressure contact with the heating roller, and presses and holds the recording paper P conveyed from the image forming unit 10 to heat it. As a result, the toner image formed on the recording paper P is fixed.

  The fixed recording paper P is sent out to the paper discharge unit 30. That is, the recording paper P passes through the nip position of the fixing paper discharge roller 31 disposed on the downstream side of conveyance of the fixing device 18, and the conveyance path of the recording paper P is further separated from the discharge path C side by the branch member 32 on the downstream side of conveyance. , Switching to the circulation reversal paper feed path D side. The recording paper P switched to the discharge side passes above the branch member 32 and is placed on the paper discharge tray by the paper discharge roller 33.

  When the branch member 32 is switched to the reverse refeed side, the recording paper P that has passed through the paper transport path a below the branch member 32 passes through the paper transport path b by the transport roller 41 of the reverse transport unit 40, and further After passing through the vertical paper transport path c on the downstream side of the transport, the paper is nipped and transported by a reverse transport roller 43 that can rotate forward and backward, and then the curved path is bent in the horizontal direction by the curved paper transport path d to supply the image forming apparatus main body. It enters a switchback paper conveyance path (horizontal path) e provided in a space formed under the paper cassette 21 and temporarily stops at a predetermined position.

  The temporarily stopped recording paper P is nipped by the reverse conveying roller 43 switched to the reverse rotation drive, rises on the vertical paper conveying path c, is passed through the paper conveying path f by the branching means 42, and introduces the recording paper. The sheet 50 is fed into the intermediate stacker section 60 (discharged paper transport path g).

  The recording sheet P accommodated in the intermediate stacker unit 60 has the printed side on the lower side. In this state, when there is an instruction to copy the back side, the recording paper P enters the paper feeding path A through the paper transport path h and reaches the registration roller 28. A toner image on the back surface is formed on the image carrier 11, and the registration roller 28 feeds the recording paper P in accordance with the timing of the image carrier 11. The recording paper P passes through the transfer unit 15 and the separator 16, enters the fixing device 18 through the conveyance path B, the toner image on the back surface is fixed, and is discharged to the outside from the paper discharge roller 33.

  The paper transport path i is a reverse paper discharge path, and is a paper transport path used when paper is discharged with its normal paper discharge direction reversed from the front and back. The recording paper P that has passed through the fixing paper discharge roller 31 from the fixing device 18 enters the paper conveyance path a by the branching member 32 and proceeds to the paper conveyance path b and the vertical paper conveyance path c when there is an instruction for reverse discharge. . When the trailing edge of the recording paper P crosses the branch portion of the paper conveyance path a and the paper conveyance path i, the recording paper P is temporarily stopped, then reversely enters the paper conveyance path i, and the paper is discharged with the front and back sides reversed.

  In such an image forming apparatus, when a sheet such as recording paper is not conveyed to a predetermined position in the conveyance path, printing is bent or shifted with respect to the sheet. In particular, in the case of double-sided printing, since the sheet conveyance path is long and the number of nips by the roller increases, a slight deviation of the sheet position gradually increases, and printing may be bent on the front and back sides. obtain.

As an example of a countermeasure for conveying a sheet to a predetermined position, there is a case where a sheet aligning device disclosed in Patent Document 1 is used. As shown in FIG. 6, the sheet aligning device moves the sheet 90 toward the reference guide 82 provided on the side of the sheet conveyance path by using a skew roller 81, thereby causing the sheet 90 to be oriented. to correct. Thereafter, the sheet 90 is nipped by the conveyance roller 84 that can be controlled to move in the axial direction of the roller, and the movement operation of the conveyance roller 84 is controlled in conjunction with the sheet side edge detection sensor 83. In this way, the mechanism is such that the sheet 90 is adjusted to a predetermined position and conveyed.
JP-A-11-189355

  However, such a sheet aligning device requires a motor, a sensor, a control board, and the like, and therefore costs are increased. In addition, it is necessary to provide a drive mechanism for moving the transport roller by a predetermined width in the axial direction, which leads to an increase in the machine size and the complexity of the apparatus due to an increase in the number of parts.

  In view of such circumstances, the present invention can convey a sheet to a predetermined position with a simple mechanism, and can eliminate bending and deviation of printing, and an image forming apparatus provided with the sheet conveying device The purpose is to provide.

  In order to achieve the above object, a sheet conveying apparatus according to the present invention includes a sheet conveying path, a regulating member that is provided on a side portion of the sheet conveying path, and that abuts against an end on the sheet side to regulate the position of the sheet. And a conveying roller provided on the upstream side in the sheet conveying direction from the restricting member, wherein the restricting member includes a first side wall portion that restricts the sheet in a wide conveying path, and a width of the restricting member. A second side wall portion that regulates the paper in a narrow conveyance path; and an inclined portion provided between the first side wall portion and the second side wall portion, wherein the conveyance roller includes a shaft, a roller portion, An elastic member that biases the roller portion in the axial direction, and the roller portion swings in the axial direction when the position of the sheet is restricted by the restriction member.

  Here, the said elastic body can be set as the structure provided in the both sides of the axial direction of the said roller part.

  Further, the conveying rollers can be provided on the upstream side and the downstream side of the inclined portion of the restricting member, or a plurality of the conveying rollers can be provided on the upstream side of the inclined portion of the restricting member. In addition, when providing a some conveyance roller in an upstream, it can be set as the structure which has a conveyance roller which does not rock | swivel downstream from the inclination part of the said limitation member.

  The restricting member may be configured to move in the axial direction of the conveying roller according to a sheet size, or the restricting member may be configured to be provided on both sides of the sheet conveying path. it can.

  An image forming apparatus according to the present invention that achieves the above object includes an image forming unit that forms an image on a sheet, and any one of the sheet conveying apparatuses described above.

  According to the sheet conveying apparatus of the present invention, since the configuration for conveying a sheet to a predetermined position can be made relatively simple, it is possible to achieve an excellent effect that the complexity of the machine can be avoided.

  Further, in the configuration of the present invention, it is not necessary to use electric parts such as a motor, a sensor, and a solenoid, so that an effect that costs can be suppressed can be achieved.

  1 and 2 show an example of an embodiment of the present invention. FIG. 1 is a plan view of the sheet conveying apparatus, and FIG. 2 is a view of the sheet conveying apparatus viewed from the sheet entering direction. This sheet conveying apparatus can be used at an appropriate location on the sheet conveying path of the image forming apparatus shown in FIG.

  The drive roller 111 has a hole penetrating in the axial direction and a key groove formed in the hole, and the drive shaft 101 is provided with a pin slidable in the key groove. The structure swings in the axial direction while receiving the rotational force from the drive shaft 101 rotated by the motor 105. The driving roller 111 is biased to a balanced position by an elastic member 104 such as a left and right spring. The driven roller 112 is in pressure contact with the driving roller 111, rotates by a frictional force received from the driving roller 111, swings in the same axial direction as the driving roller 111, and is urged by an elastic member 104 such as a spring. However, the driven shaft 102 of the driven roller 112 does not rotate but only the roller portion rotates. The conveyance roller 110 including the driving roller 111 and the driven roller 112 is configured to nip the sheet 100 passing through the sheet conveyance path from above and below and adjust the sheet position in the axial direction.

  For the engagement between the drive roller 111 and the drive shaft 101, a spline shaft or ball spline shaft structure can be adopted in addition to the above-described key groove and pin configuration.

  A regulating plate 103 as a regulating member that regulates the position of the end of the paper forms a part of the side wall located on the side of the sheet conveying path, and adjusts the sheet position so that the inlet side of the wide conveying path The first side wall portion 103a and the second side wall portion 103b on the outlet side of the narrow conveyance path are connected by an inclined portion 103c. The conveyed sheet 100 changes its angle or moves in a direction perpendicular to the sheet conveying direction when the sheet side end abuts against the inclined portion 103 c of the regulating plate 103. Thus, if the sheet 100 can be brought into a state of being in close contact with the second side wall portion 103b on the exit side of the conveyance path, the sheet 100 has been conveyed to a predetermined position.

  The adjustment allowance s that can change the seat position is determined by the amount of displacement between the first side wall 103a and the second side wall 103b before and after the regulating plate. Here, in order to adjust the sheet position, the sheet 100 is advanced in advance so that the sheet side end portion is included in the adjustment allowance s.

  In addition, the regulation plate 103 can be provided on both sides of the conveyance path. By doing so, when the sheet 100 enters the conveyance path, the position can be adjusted even if the sheet 100 is displaced toward one of the regulating plates 103 with respect to a predetermined position. Therefore, there is an advantage that it is not necessary to strictly manage the position when the sheet 100 is advanced, compared to the case where the restriction plate 103 is provided only on one side.

  Note that the shape of the inclined portion 103c of the restriction plate 103 must be a shape in which the first side wall portion 103a and the second side wall portion 103b before and after the restriction plate are smoothly connected. Otherwise, the position of the sheet 100 cannot be adjusted because the sheet 100 is caught without being smoothly moved or buckled due to the reaction force from the elastic member 104.

  A coil spring can be used as the elastic member 104. Here, in order to prevent the sheet 100 from buckling when the conveyance roller 110 swings in a state where the sheet 100 is nipped and the sheet 100 is pressed against the side wall portion through the conveyance roller 110, the spring constant of the elastic member 104 is: It must be small enough.

  The positional relationship between the transport roller 110 and the regulating plate 103 is an important point in configuring the present invention. In the positional relationship in the roller axis direction, it is preferable to adjust the distance from the conveying roller 110 to the regulating plate 103 for each sheet size. For example, if the end of the sheet 100 is nipped, the sheet end on the non-nipped side is easily turned over, which may cause a paper jam or when the distance from the conveying roller 110 to the regulating plate 103 is long. Is likely to be buckled by the reaction force from the elastic member 104. Therefore, it is desirable that the restriction plate 103 can be moved to a predetermined position according to the sheet size.

  With respect to the positional relationship between the conveying roller 110 and the regulating plate 103 in the sheet conveying direction, an example will be shown below and the movement of the sheet 100 and the conveying roller 110 will be described.

  In the first embodiment illustrated in FIG. 3, the conveyance rollers 110 are provided at two locations on the upstream side and the downstream side of the inclined portion of the restriction plate, and the inclined portion 103 c of the restriction plate 103 is located between the conveyance rollers 110. is there. Here, the conveyance roller 110 that nips the sheet 100 first is a first conveyance roller 110a, and the roller that nips the sheet 100 later is a second conveyance roller 110b.

  In FIG. 3A, the sheet 100 that has entered the conveyance path is nipped by the first conveyance roller 110a, and the corner of the leading end of the sheet 100 is in contact with the inclined portion 103c. Thereafter, as shown in (b), the first conveying roller 110a is pushed to the left in the drawing, and a force is applied to the sheet 100 in the direction of the regulating plate as a reaction force of the elastic member 104. Accordingly, the sheet 100 advances along the regulation plate 103 and is nipped by the second conveying roller 110b with a certain angle. As it goes on as it is, as shown in (c), the second conveying roller 110b is also pushed to the left side. When the nip of the first conveying roller 110a is released in this state, the sheet 100 is pressed tightly against the second side wall portion 103b of the restricting plate 103 by the reaction force of the elastic member 104 applied to the second conveying roller 110b. Adjusted to position. Thus, as shown in (d), the sheet 100 is conveyed in contact with the second side wall portion 103b.

  In the second embodiment shown in FIG. 4, there are two transport rollers 110 that swing in the axial direction along the transport path, and a third transport roller 115 that does not swing on the downstream side of the transport. The inclined portion 103c is between the second transport roller 110b that swings and the third transport roller 115 that does not swing.

  In FIG. 4A, the corner portion of the leading end of the sheet 100 nipped by the two swinging first and second transport rollers 110a and 110b is in contact with the inclined portion 103c. Thereafter, as shown in (b), while receiving the reaction force of the elastic member 104, the first and second transport rollers 110a and 110b and the sheet 100 move to the left in the drawing and follow the inclined portion 103c of the regulating plate 103. In this way, it is conveyed. Next, in (c), the nip of the swinging first transport roller 110 a is released, and the third transport roller 115 that does not swing continues to nip the sheet 100. At this time, the second conveying roller 110b receives a reaction force from the elastic member 104, but the third conveying roller 115 that does not swing is nipped, so the sheet 100 does not rotate, as shown in FIG. It will be conveyed in contact with the second side wall 103b.

  These embodiments are merely examples, and other arrangements and configurations may be considered by adjusting the angle of the regulating plate, the spring constant, the conveyance speed, the positional relationship of the conveyance rollers, and the like.

  These sheet conveying apparatuses are generally considered to be provided in front of the image forming unit 10 in FIG. That is, it should be provided near the paper feed path A. Furthermore, in the case of double-sided printing, it is considered that the position can be adjusted more reliably if the path is provided in the circulation reversal paper feed path D in consideration of the long path.

It is a figure which shows the sheet conveying apparatus of this invention. It is the figure which looked at the sheet conveying apparatus of this invention from the approach direction of the sheet | seat. FIG. 6 is a diagram illustrating the movement of the sheet and the roller according to the first exemplary embodiment, and illustrates how the sheet is conveyed in stages from (a) to (d). FIG. 9 is a diagram illustrating the movement of a sheet and a roller according to the second embodiment, and illustrates how the sheet is conveyed in stages from (a) to (d). FIG. 4 is a diagram illustrating a sheet conveyance path of a double-sided image forming apparatus. It is a figure which shows the conventional paper aligning apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image formation part 20 Paper feed part 30 Paper discharge part 40 Reverse conveyance part 50 Recording paper introduction part 60 Intermediate stacker part 70 Refeed part 100 Sheet 101 Drive shaft 102 Drive shaft 103 Restriction plate 103a 1st side wall part 103b 2nd side wall Part 103c Inclined part 104 Elastic member 105 Motor 110 Conveying roller 111 Driving roller 112 Driven roller 115 Third conveying roller s that does not swing in the axial direction Adjustment allowance

Claims (8)

A sheet conveyance path;
A regulating member that is provided at a side portion of the sheet conveying path and that abuts against the sheet side end portion to regulate the position of the sheet;
A transport roller provided upstream of the regulating member in the paper transport direction;
In a sheet conveying apparatus having
The regulating member includes a first side wall portion that regulates the paper in a wide conveyance path, a second side wall portion that regulates the paper in a narrow conveyance path, the first side wall portion, and the second side wall portion. Having an inclined portion provided between
The conveying roller includes a shaft, a roller portion, and an elastic member that urges the roller portion in the axial direction. When the position of the sheet is restricted by the restriction member, the roller portion is A sheet conveying device that swings in a direction.   The sheet conveying apparatus according to claim 1, wherein the elastic member is provided on both sides of the roller portion in the axial direction.   The sheet conveying apparatus according to claim 1, wherein the conveying rollers are provided on an upstream side and a downstream side of the inclined portion of the regulating member.   The sheet conveying apparatus according to claim 1, wherein a plurality of the conveying rollers are provided on the upstream side of the inclined portion of the regulating member.   The sheet conveying apparatus according to claim 4, further comprising a conveying roller that does not swing downstream from the inclined portion of the regulating member.   The sheet conveying apparatus according to claim 1, wherein the regulating member moves in an axial direction of the conveying roller according to a sheet size.   The sheet conveying apparatus according to claim 1, wherein the regulating member is provided on both sides of the sheet conveying path.   An image forming apparatus comprising: an image forming unit that forms an image on a sheet; and the sheet conveying device according to claim 1.

Images