JP2014055071A - Sheet material feeder and image forming apparatus - Google Patents

Abstract

There is provided a sheet material feeding device capable of suppressing a phenomenon in which a sheet material remaining after being curled is bounced by an upstream end portion or the like of the sheet material that has been curled and fed back to the upstream side.
A sheet material lift member 601 disposed on a lower surface side on the downstream side of a sheet material T placed on a sheet material placement portion 65 and rising so as to lift a downstream end portion of the sheet material T, and a sheet Between the feeding roller 66 that feeds the sheet material T by rotating the feeding roller 66 while contacting the upper surface of the sheet material T lifted by the material lifting member 601, and the feeding roller 66. The sheet member T is pressed and the sheet member T is rolled up one by one, and the downstream side of the sheet material T disposed on the upstream side of the sheeting member 611 and wound on the upstream side of the sheeting member 611 by the sheeting member 611 A receiving portion 621 for receiving the side end portion. The upper end edge of the receiving member 621 is disposed below the upper surface of the spreading member 611.
[Selection] Figure 13

Description

  The present invention relates to a sheet material feeding apparatus that feeds a sheet material to an image forming unit or the like in the image forming apparatus, and an image forming apparatus including the sheet material feeding apparatus.

The sheet material feeding device is a device that constitutes a part of an image forming apparatus such as a copying machine or a printer, and feeds a sheet material to an image forming unit of the image forming apparatus. The sheet material feeding device is, for example, arranged on the lower surface side on the downstream side of the sheet material placed on the sheet material placing portion on which the sheet material is placed, and on the downstream side of the sheet material The sheet material lift member that rises to lift the edge and descends to lower the downstream edge of the sheet material, and rotates while the feeding roller contacts the upper surface of the sheet material lifted by the sheet material lift member A sheet feeding roller that feeds the sheet material, and a scooping member that is arranged to press the sheet material between the sheet feeding roller and rolls a bundle of sheet materials one by one (for example, See Patent Document 1 below).
According to such a sheet material feeding device, the sheet material lift member is lifted to lift the downstream end of the sheet material, and in this state, the sheet roller is rotated while being in contact with the upper surface of the sheet material. Sheet material can be sent out.

JP 2009-2442025 A

By the way, in the sheet material feeding apparatus described in Patent Document 1, the “sheet material back phenomenon” described below is likely to occur. FIG. 14 is a schematic configuration diagram showing the periphery of the separation member 503 in the conventional sheet material feeding apparatus. FIG. 15 is an explanatory diagram illustrating a sheet material back phenomenon that occurs in the sheet material feeding apparatus illustrated in FIG. 14.
As shown in FIG. 14, the downstream side of the sheet material lift member 501 that moves up and down the downstream side (left end side in FIG. 14) of the sheet material S placed on the sheet material placement part (not shown). A guide plate 520 having a curved shape for guiding the downstream end of the sheet material S to be fed between the feeding roller 510 and the separating member 503 is provided between the end portion and the separating member 503.

  However, as shown in FIGS. 14 and 15, the sheet material back phenomenon may occur in the structure in which the guide plate 520 is simply provided between the downstream end portion of the sheet material lift member 501 and the separating member 503. is there. In the sheet material back phenomenon, the sheet material S <b> 2 (next sheet material) remaining on the upstream side of the rolling member after being rolled by the rolling member 503 is rolled by the rolling member 503 (on the feeding roller 510). When the sheet material S2 (next sheet material) is separated from the sheet material S1 (previous sheet material) fed to the sheet material lift member 501 and falls to the sheet material lift member 501, the curved guide plate is used. It is repelled by the top (projected portion) 521 of 520, the upstream end S1t of the sheet material S1, etc., and retreats to the upstream side (right side in FIG. 15) as shown by the arrow D1 in FIG. is there.

When this sheet material back phenomenon occurs, the upper surface of the next sheet material S2 does not come into contact with the feeding roller 510 even if the sheet material lift member 501 rises again for feeding the next sheet material S2. A problem that the next sheet material S2 is not sent to the downstream side (the side of the rolling member 503) is likely to occur.
Therefore, as a technique for preventing the sheet material back phenomenon, the upstream end portion of the sheet material that has receded due to the sheet material back phenomenon hits a sheet material placement portion (not shown) located on the upstream side of the separating member 503. A technique for providing a rear end stopper or the like is conceivable.

However, since various sizes of sheet material are placed on the manual feed tray and the document conveying device, which are examples of the sheet material feeding device, the rear end that needs to be changed according to the size of the sheet material It is not preferable to provide a stopper.
Therefore, there is a demand for a sheet material feeding apparatus that can cope with sheet materials of various sizes and can suppress the above-described sheet material back phenomenon.

In the present invention, the next sheet material left on the upstream side by being rolled by the rolling member is flipped by the upstream end of the previous sheet material that has been rolled by the rolling member and fed to the downstream side, etc. An object of the present invention is to provide a sheet material feeding device that can suppress the phenomenon of retreating to the upstream side (sheet material back phenomenon) and can cope with sheet materials of various sizes.
Another object of the present invention is to provide an image forming apparatus including the sheet material feeding device.

  The present invention is a sheet material feeding device that feeds a sheet material, and is placed on the sheet material placing unit on which the sheet material before being fed is placed, and on the sheet material placing unit A sheet material lift member disposed on the lower surface side of the downstream side of the sheet material and rising to raise the downstream end of the sheet material and descending to lower the downstream end of the sheet material; and the sheet material lift member A feed roller that can be disposed opposite to the upper surface of the sheet material, the feed roller feeding out the sheet material by rotating the feed roller in contact with the upper surface of the sheet material lifted by the sheet material lift member, and The sheet material is disposed so as to press the sheet material between the sheet feeding rollers and the sheet material is wound one by one, and the sheet material is disposed on the upstream side of the sheeting member and is wound by the sheeting member. Above the thatched member A receiving unit receiving a downstream end of the remaining sheet material to the side, a sheet material feeding device comprising a.

  Moreover, it is preferable that the said receiving part is formed in the shape of a tongue piece from the flexible film sheet.

  Moreover, it is preferable that the said receiving part is formed by cut | disconnecting a part of said film sheet larger than this receiving part in the shape of a tongue piece.

  Moreover, it is preferable to further include a holding member that holds the winding member, and the holding member has a pressing protrusion that presses the receiving portion toward the sheet material lift member.

  Further, the holding member is configured to generate a biasing force in a direction in which the whirling member is brought close to the feeding roller, and the pressing protrusion is formed by pressing the whirling member against the feeding roller. It is preferable that the holding member is configured to press the receiving portion in a state where the holding member moves in a direction away from the feeding roller.

  The present invention also relates to an image forming apparatus including the sheet material feeding device and an image forming unit that forms an image on the sheet material fed by the sheet material feeding device.

According to the present invention, the next sheet material left on the upstream side by the rolling member is flipped by the upstream end of the previous sheet material that has been rolled by the winding member and fed downstream. Thus, it is possible to provide a sheet material feeding device that can suppress the phenomenon of retreating to the upstream side and can handle various sizes of sheet materials.
In addition, according to the present invention, an image forming apparatus including the sheet material feeding device can be provided.

FIG. 2 is a side view for explaining the arrangement of each component in the copier 1 as an embodiment of the image forming apparatus of the present invention. FIG. 6 is a perspective view of a manual sheet feeding portion 64 with the manual tray 65 opened when viewed from obliquely upward on the right side surface of the apparatus main body M. FIG. 6 is a perspective view of a manual feed tray 65, a feed roller 66, and the like constituting the manual feed unit 64. FIG. 6 is an enlarged perspective view showing the arrangement of the lower-part separating member 611 and the receiving portion 621 with the member supporting the feeding roller 66 omitted. FIG. 5 is a perspective view illustrating a state where a feeding roller 66 is removed from the state illustrated in FIG. 4. FIG. 6 is an explanatory diagram showing a positional relationship among a feeding roller 66, a sheet material lift member 601 and a separating member 611 before starting a feeding operation. FIG. 6 is an explanatory diagram showing a state in which the downstream end of the paper T placed on the manual feed tray 65 is pressed against the feeding roller 66 by the sheet material lift member 601 in order to feed the paper T by the feeding roller 66. is there. It is a perspective view which shows the state with which the 1st holding member 642 and the 2nd holding member 643 are continuing in planar shape about the holding member 641 holding the spreading member 611. It is a perspective view which shows the state in which the 1st holding member 642 and the 2nd holding member 643 are in the bending state about the holding member 641 holding the rolling member 611. FIG. 6 is an explanatory diagram illustrating a state in which two sheets of paper T are sandwiched between a separating member 611 and a feeding roller 66 by a feeding operation of a feeding roller 66. The feeding process by the feeding roller 66 proceeds from the state shown in FIG. 10, the next sheet T <b> 2 is rolled by the winding member 611, and the downstream end portion of the next sheet T <b> 2 is left on the upstream side of the winding member 611. It is explanatory drawing which shows the state. FIG. 12 is an explanatory diagram illustrating a state in which the feeding process by the feeding roller 66 further proceeds from the state illustrated in FIG. 11 and the next sheet T2 starts to fall from the winding member 611 to the sheet material lift member 601 side. The feeding process by the feeding roller 66 further proceeds from the state shown in FIG. 12, and the next sheet T2 falls from the separating member 611 to the sheet material lift member 601 side, and the receiving portion 621 above the sheet material lift member 601. It is explanatory drawing which shows the state received by. It is a schematic block diagram which shows the periphery of the separating member 503 in the conventional sheet material feeding apparatus. FIG. 15 is an explanatory diagram illustrating a sheet material back phenomenon that occurs in the sheet material feeding apparatus illustrated in FIG. 14.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
With reference to FIG. 1, the overall structure of a copier 1 as an image forming apparatus in the present embodiment will be described. FIG. 1 is a side view for explaining the arrangement of each component of the copier 1.

  As shown in FIG. 1, a copier 1 as an image forming apparatus includes an image reading device 200 and an apparatus main body M.

The image reading apparatus 200 includes an image reading unit 201 incorporated in the upper part of the apparatus main body M, and a reading unit cover 210 that covers the upper surface of the image reading unit 201 so as to be opened and closed. The upper surface of the image reading unit 201 is a document placement surface 202 on which a document (sheet material) G is placed. The document G is placed on the document placement surface 202 with the reading unit cover 210 opened.
The image reading apparatus 200 reads an image of the document G placed on the document placement surface 202 by the image reading unit 201 and sends the read image information to the image forming unit GK incorporated in the apparatus main body M.

  The apparatus body M supplies an image forming unit GK that forms a predetermined toner image on a sheet T as a sheet-like transfer material based on image information sent from the image reading apparatus 200, and supplies the sheet T to the image forming unit GK. And a paper supply / discharge unit KH that discharges the paper T on which the toner image is formed. The outer shape of the apparatus main body M is configured by a case body BD as a casing.

  As shown in FIG. 1, the image forming unit GK includes a photosensitive drum 2 as an image carrier (photosensitive member), a charging unit 10, a laser scanner unit 4 as an exposure unit, a developing device 16, and a toner cartridge. 5, a toner supply unit 6, a drum cleaning unit 11, a static eliminator 12, a transfer roller 8, and a fixing unit 9.

  As shown in FIG. 1, the paper feed / discharge unit KH includes a paper feed cassette 52, a manual paper feed unit 64, a transport path L for paper T, a registration roller pair 80, and a paper discharge unit 50.

Hereinafter, each configuration of the image forming unit GK and the paper supply / discharge unit KH will be described in detail.
First, the image forming unit GK will be described.
In the image forming unit GK, charging by the charging units 10a, 10b, 10c, and 10d in order from the upstream side to the downstream side in order along the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d, the laser scanner unit 4a, 4b, 4c, 4d exposure, development devices 16a, 16b, 16c, 16d development, intermediate transfer belt 7 and primary transfer rollers 37a, 37b, 37c, 37d primary transfer, static eliminators 12a, 12b, 12c, 12d Is eliminated, and cleaning is performed by the drum cleaning units 11a, 11b, 11c, and 11d.
Further, in the image forming unit GK, secondary transfer by the intermediate transfer belt 7, the secondary transfer roller 8 and the counter roller 18, and fixing by the fixing unit 9 are performed.

  Each of the photosensitive drums 2a, 2b, 2c, and 2d is formed of a cylindrical member and functions as a photosensitive member or an image carrier. Each of the photosensitive drums 2 a, 2 b, 2 c, and 2 d is disposed so as to be rotatable in the direction of an arrow about an axis that extends in a direction orthogonal to the traveling direction of the intermediate transfer belt 7. An electrostatic latent image can be formed on the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d.

  Each of the charging units 10a, 10b, 10c, and 10d is disposed to face the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the charging units 10a, 10b, 10c, and 10d uniformly charges the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d negatively (minus polarity) or positively (plus polarity).

  The laser scanner units 4a, 4b, 4c, and 4d function as exposure units, and are spaced apart from the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the laser scanner units 4a, 4b, 4c, and 4d includes a laser light source (not shown), a polygon mirror, a polygon mirror driving motor, and the like.

  Each of the laser scanner units 4a, 4b, 4c, and 4d scans and exposes the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d based on image information input from an external device such as a PC (personal computer). The scanning exposure is performed by each of the laser scanner units 4a, 4b, 4c, and 4d, thereby removing the charges on the exposed portions of the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Thereby, electrostatic latent images are formed on the respective surfaces of the photosensitive drums 2a, 2b, 2c, and 2d.

  The developing devices 16a, 16b, 16c, and 16d are provided corresponding to the photosensitive drums 2a, 2b, 2c, and 2d, respectively, and are disposed to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the developing devices 16a, 16b, 16c, and 16d attaches the toner of each color to the electrostatic latent image formed on the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d, and converts the color toner image into the photosensitive drum. 2a, 2b, 2c and 2d are formed on the respective surfaces. Each of the developing devices 16a, 16b, 16c, and 16d corresponds to four colors of yellow, cyan, magenta, and black. Each of the developing devices 16a, 16b, 16c, and 16d includes a developing roller disposed opposite to the surface of the photosensitive drums 2a, 2b, 2c, and 2d, a stirring roller for stirring the toner, and the like.

  Each of the toner cartridges 5a, 5b, 5c, and 5d is provided corresponding to each of the developing devices 16a, 16b, 16c, and 16d, and each color toner supplied to each of the developing devices 16a, 16b, 16c, and 16d. To accommodate. Each of the toner cartridges 5a, 5b, 5c, and 5d accommodates yellow toner, cyan toner, magenta toner, and black toner.

  The toner supply units 6a, 6b, 6c, and 6d are provided corresponding to the toner cartridges 5a, 5b, 5c, and 5d and the developing devices 16a, 16b, 16c, and 16d, respectively. The toners of the respective colors accommodated in 5d are supplied to the developing devices 16a, 16b, 16c, and 16d, respectively. Each of the toner supply units 6a, 6b, 6c, and 6d and each of the developing devices 16a, 16b, 16c, and 16d are connected by a toner supply path (not shown).

  To the intermediate transfer belt 7, the toner images of the respective colors formed on the photosensitive drums 2a, 2b, 2c, and 2d are sequentially primary-transferred. The intermediate transfer belt 7 is stretched around a driven roller 35, a counter roller 18 including a driving roller, a tension roller 36, and the like. Since the tension roller 36 biases the intermediate transfer belt 7 from the inside to the outside, a predetermined tension is applied to the intermediate transfer belt 7.

  Primary transfer rollers 37a, 37b, 37c, and 37d are arranged to face each other on the side opposite to the photosensitive drums 2a, 2b, 2c, and 2d with the intermediate transfer belt 7 interposed therebetween.

  A predetermined portion of the intermediate transfer belt 7 is sandwiched between the primary transfer rollers 37a, 37b, 37c, and 37d and the photosensitive drums 2a, 2b, 2c, and 2d, respectively. The predetermined portion thus sandwiched is pressed against the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d. Primary transfer nips N1a, N1b, N1c, and N1d are formed between the photosensitive drums 2a, 2b, 2c, and 2d and the primary transfer rollers 37a, 37b, 37c, and 37d, respectively. In each of the primary transfer nips N1a, N1b, N1c, and N1d, the toner images of the respective colors developed on the photosensitive drums 2a, 2b, 2c, and 2d are sequentially primary-transferred onto the intermediate transfer belt 7, respectively. As a result, a full-color toner image is formed on the intermediate transfer belt 7.

  To the primary transfer rollers 37a, 37b, 37c, and 37d, toner images of the respective colors formed on the photosensitive drums 2a, 2b, 2c, and 2d are respectively transferred to the intermediate transfer belt 7 by a primary transfer bias applying unit (not shown). A primary transfer bias for transferring the toner image is applied.

  The static eliminators 12a, 12b, 12c, and 12d are arranged to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, respectively. The static eliminators 12a, 12b, 12c, and 12d respectively irradiate the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d to irradiate light, and the photosensitive drums 2a, 2b, and 2c after the primary transfer is performed. 2d, each surface is neutralized (charge is removed).

  The drum cleaning units 11a, 11b, 11c, and 11d are disposed to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, respectively. Each of the drum cleaning units 11a, 11b, 11c, and 11d removes toner and adhering matter remaining on the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, and conveys the removed toner to a predetermined recovery mechanism. And collect it.

  The secondary transfer roller 8 secondarily transfers the full-color toner image primarily transferred to the intermediate transfer belt 7 onto the paper T. A secondary transfer bias for transferring the full color toner image formed on the intermediate transfer belt 7 to the paper T is applied to the secondary transfer roller 8 by a secondary transfer bias applying unit (not shown).

  The secondary transfer roller 8 contacts or separates from the intermediate transfer belt 7. Specifically, the secondary transfer roller 8 is configured to be movable between a contact position where the secondary transfer roller 8 is in contact with the intermediate transfer belt 7 and a spaced position where the secondary transfer roller 8 is separated from the intermediate transfer belt 7. Specifically, the secondary transfer roller 8 is disposed at a contact position when the full-color toner image primarily transferred onto the surface of the intermediate transfer belt 7 is secondarily transferred to the paper T, and in other cases. It is arranged at a separated position.

  A counter roller 18 is disposed on the opposite side of the intermediate transfer belt 7 from the secondary transfer roller 8. A predetermined portion of the intermediate transfer belt 7 is sandwiched between the secondary transfer roller 8 and the opposing roller 18. Then, the paper T is pressed against the outer surface of the intermediate transfer belt 7 (the surface on which the toner image is primarily transferred). A secondary transfer nip N <b> 2 is formed between the intermediate transfer belt 7 and the secondary transfer roller 8. In the secondary transfer nip N2, the full-color toner image primarily transferred to the intermediate transfer belt 7 is secondarily transferred to the paper T.

  The fixing unit 9 melts and presses the toner of each color constituting the toner image secondarily transferred onto the paper T and fixes the toner on the paper T. The fixing unit 9 includes a heating rotator 9a heated by a heater and a pressure rotator 9b pressed against the heating rotator 9a. The heating rotator 9a and the pressure rotator 9b sandwich and pressurize the paper T onto which the toner image has been secondarily transferred, and convey the paper T. When the paper T is conveyed while being sandwiched between the heating rotator 9a and the pressure rotator 9b, the toner transferred to the paper T is fixed on the paper T by being melted and pressurized. Is done.

Next, the paper supply / discharge unit KH will be described.
As shown in FIG. 1, in the lower part of the apparatus main body M, a single paper feed cassette 52 that stores paper T is disposed. The paper feed cassette 52 is configured to be drawable from the apparatus main body M in the horizontal direction. In the paper feed cassette 52, a placement plate 60 on which the paper T is placed is disposed. In the paper feed cassette 52, the paper T is stored in a state of being stacked on the placement plate 60. The paper T placed on the placement plate 60 is sent out to the transport path L by the cassette paper feed unit 51 arranged at the paper feed side end of the paper feed cassette 52 (the right end in FIG. 1). The cassette paper feeding unit 51 includes a forward feed roller 61 for taking out the paper T on the placement plate 60 and a paper feed roller pair 81 for feeding the paper T one by one to the transport path L. Is provided.

  On the right side surface (right side in FIG. 1) of the apparatus main body M, a manual sheet feeding unit 64 is provided as a sheet material feeding device that feeds the paper T as a sheet material. The manual paper feed unit 64 is provided mainly for feeding paper T of a size and type different from the paper T set in the paper feed cassette 52 to the first transport path L1 via the manual transport path La. It is done. The manual paper feed unit 64 includes a manual feed tray 65 that forms part of the right side surface of the apparatus main body M in the closed state, and a feed roller 66. The lower end of the manual feed tray 65 is attached to the vicinity of the feeding roller 66 so as to be rotatable (openable and closable). The open manual feed tray 65 functions as a sheet material placement unit on which the paper T before being fed is placed. The feed roller 66 feeds the paper T placed on the open manual feed tray 65 to the manual feed path La.

The manual sheet feeder 64 of the present embodiment is devised to prevent the sheet material back phenomenon from occurring. The sheet material back phenomenon refers to a sheet T that has been sent out first when a plurality of sheets T placed in a stacked state on the manual feed tray 65 are sent one by one by the feed roller 66 to the manual feed path La one by one. This is a phenomenon in which the succeeding paper T is retracted to the upstream side by the upstream end of the sheet.
Details of the manual sheet feeder 64 including such a device will be described later.

  The conveyance path L for conveying the paper T includes a first conveyance path L1 from the cassette paper feeding unit 51 to the secondary transfer nip N2, a second conveyance path L2 from the secondary transfer nip N2 to the fixing unit 9, and a fixing unit. 9 to the paper discharge unit 50, the manual feed path La for joining the paper supplied from the paper feed unit 64 to the first transport path L1, and the third transport path L3 from the downstream side to the upstream side. And a return transport path Lb that reverses the front and back of the sheet to be transported to the first transport path L1.

  The first transport path L1 transports the paper T stored in the paper feed cassette 52 toward the image forming unit GK. The manual feed path La transports the paper T accommodated in the manual paper feed unit 64 toward a registration roller pair 80 described later.

Moreover, the 1st junction part P1 and the 2nd junction part P2 are provided in the middle of the 1st conveyance path L1. A first branch portion Q1 is provided in the middle of the third transport path L3.
The first joining part P1 is a joining part where the manual feed path La joins the first transport path L1. The second junction P2 is a junction where the return conveyance path Lb merges with the first conveyance path L1.
The first branch portion Q1 is a branch portion where the return transport path Lb branches from the third transport path L3.

  In the middle of the first conveyance path L1 (specifically, between the second joining portion P2 and the secondary transfer roller 8), a sheet detection sensor (not shown) for detecting the sheet T, A registration roller pair 80 is arranged to synchronize with skew (oblique sheet feeding) correction and toner image formation in the image forming unit GK. The paper detection sensor is disposed immediately before the registration roller pair 80 in the transport direction of the paper T (upstream in the transport direction). The registration roller pair 80 conveys the paper T by performing the above-described correction and timing adjustment based on detection signal information from the paper detection sensor.

  A first conveyance roller pair 82 as a first roller is disposed between the first merging portion P1 and the second merging portion P2 in the first conveying path L1. The first transport roller pair 82 is disposed on the downstream side of the paper feed roller pair 81, sandwiches the paper T transported by the paper feed roller pair 81, and transports the paper T to a registration roller pair 80 as a second roller.

  The return conveyance path Lb is a conveyance path that is provided to make the opposite surface (unprinted surface) opposite to the already printed surface to the intermediate transfer belt 7 when performing duplex printing on the paper T. In the return conveyance path Lb, a plurality of second conveyance roller pairs 83 that convey the paper T toward the second junction P2 are arranged at predetermined intervals. According to the return transport path Lb, the paper T transported from the first branching section Q1 to the paper discharge section 50 is turned upside down and returned to the first transport path L1 and arranged upstream of the secondary transfer roller 8. It can be conveyed to the upstream side of the pair of registration rollers 80. A predetermined toner image is transferred onto the unprinted surface in the secondary transfer nip N2 on the paper T that is reversed upside down by the return conveyance path Lb.

  A branch member 58 is provided in the first branch portion Q1. The branching member 58 branches the transport direction of the paper T that is transported from the fixing unit 9 and transports the third transport path L3 from the upstream side toward the downstream side in a direction toward the paper discharge unit 50 and the paper discharge unit 50. The conveyance direction of the paper T that conveys the third conveyance path L3 from the downstream side toward the upstream side is branched in a direction toward the return conveyance path Lb.

  A paper discharge unit 50 is formed at the end of the third transport path L3. The paper discharge unit 50 is disposed on the upper side of the apparatus main body M. The paper discharge unit 50 opens toward the left side of the apparatus body M (left side in FIG. 1). The paper discharge unit 50 discharges the paper T to the outside of the apparatus main body M. The paper discharge unit 50 includes a discharge roller pair 53. According to the discharge roller pair 53, the paper T conveyed from the upstream side to the downstream side in the third conveyance path L3 is discharged to the outside of the apparatus main body M, and the conveyance direction of the paper T is reversed in the paper discharge unit 50. Thus, the paper T can be transported toward the upstream side of the third transport path L3.

On the opening side of the paper discharge unit 50, a paper discharge stacking unit M1 is formed. The paper discharge stacking unit M1 is formed on the upper surface (outer surface) of the apparatus main body M. The paper discharge stacking unit M1 is a part formed by the upper surface of the apparatus main body M being depressed downward. The bottom surface of the paper discharge stacking unit M1 is formed by a top cover member M2 as an opening / closing member that constitutes a part of the top surface of the apparatus main body M. A sheet T on which a predetermined toner image is formed and discharged from the paper discharge unit 50 is stacked and integrated on the upper surface of the top cover member M2 forming the paper discharge stacking unit M1.
A paper detection sensor is disposed at a predetermined position on each conveyance path.

Next, with reference to FIG. 1, the operation of the copier 1 of the present embodiment will be briefly described.
First, a case where single-sided printing is performed on the paper T stored in the paper feed cassette 52 will be described.
The paper T stored in the paper feed cassette 52 is sent out to the first transport path L1 by the forward feed roller 61 and the paper feed roller pair 81, and then the first transport path L1 and the first transport path L1 through the first transport path L1. The sheet is conveyed to the registration roller pair 80 by the one conveyance roller pair 82.
In the registration roller pair 80, skew correction of the paper T and timing adjustment with toner image formation in the image forming unit GK are performed.

The paper T discharged from the registration roller pair 80 is introduced between the intermediate transfer belt 7 and the secondary transfer roller 8 (secondary transfer nip N2) via the first conveyance path L1. A toner image is transferred onto the paper T between the intermediate transfer belt 7 and the secondary transfer roller 8.
Thereafter, the paper T is discharged from between the intermediate transfer belt 7 and the secondary transfer roller 8, and is interposed between the heating rotator 9a and the pressure rotator 9b in the fixing unit 9 via the second conveyance path L2. Introduced into the fixing nip. Then, the toner melts in the fixing nip, and the toner is fixed on the paper T.

Next, the paper T is transported to the paper discharge unit 50 through the third transport path L3, and is discharged from the paper discharge unit 50 to the paper discharge stacking unit M1 by the discharge roller pair 53.
In this way, single-sided printing of the paper T stored in the paper feed cassette 52 is completed.

  When single-sided printing is performed on the paper T placed on the manual feed tray 65, the paper T placed on the manual feed tray 65 is sent out to the manual feed path La by the feed roller 66, and then the first joining unit It is conveyed to the registration roller pair 80 via P1 and the first conveyance path L1. Subsequent operations are the same as the one-side printing operation of the paper T accommodated in the paper feed cassette 52 described above, and a description thereof will be omitted.

Next, the operation of the copier 1 when performing duplex printing will be described.
In the case of single-sided printing, as described above, the paper T on which single-sided printing has been performed is discharged from the paper discharge unit 50 to the paper discharge stacking unit M1, and the printing operation is completed.
On the other hand, when performing double-sided printing, the paper T on which single-sided printing has been performed is reversed from the time of single-sided printing and conveyed again to the registration roller pair 80 via the return conveyance path Lb. Then, double-sided printing is performed on the paper T.

  More specifically, the operation is the same as the above-described single-sided printing operation until the paper T on which single-sided printing has been performed is discharged from the paper discharge unit 50 by the discharge roller pair 53. Thus, in the case of double-sided printing, in a state where the paper T on which single-sided printing has been performed is held by the discharge roller pair 53, the rotation of the discharge roller pair 53 is stopped and rotated in the reverse direction. When the discharge roller pair 53 is thus rotated in the reverse direction, the paper T held by the discharge roller pair 53 moves in the reverse direction (the direction from the paper discharge unit 50 toward the first branching unit Q1) along the third conveyance path L3. ).

  As described above, when the paper T is transported in the reverse direction along the third transport path L3, the paper T is branched to the return transport path Lb by the branching member 58, and thereafter, via the second junction P2. Then, it joins the first transport path L1. Here, the paper T is turned upside down from the one-side printing.

  Further, the paper T is subjected to the correction or the adjustment by the registration roller pair 80, and is introduced into the secondary transfer nip N2 through the first conveyance path L1. Since the unprinted surface of the sheet T passes through the return conveyance path Lb and faces the intermediate transfer belt 7, the toner image is transferred to the unprinted surface, and as a result, duplex printing is performed.

  Next, with reference to FIGS. 2 to 13, the details of the manual sheet feeder 64 which is a characteristic part of the present invention will be described. FIG. 2 is a perspective view of the manual sheet feeder 64 with the manual tray 65 opened, as viewed obliquely from the upper right side of the apparatus body M. FIG. FIG. 3 is a perspective view of the manual feed tray 65, the feed roller 66, and the like constituting the manual paper feed unit 64. FIG. 4 is an enlarged perspective view showing the arrangement of the lower separating member 611 and the receiving portion 621 with the member supporting the feeding roller 66 omitted. FIG. 5 is a perspective view showing a state in which the feeding roller 66 is removed from the state shown in FIG.

  FIG. 6 is an explanatory diagram showing a positional relationship among the feeding roller 66, the sheet material lifting member 601, and the separating member 611 before the feeding operation is started. FIG. 7 shows a state where the downstream end of the paper T placed on the manual feed tray 65 is pressed by the sheet feeding lift member 601 by the sheet feeding lift 66 in order to feed the paper T by the feeding roller 66. It is explanatory drawing shown. FIG. 8 is a perspective view showing a state in which the first holding member 642 and the second holding member 643 are continuous in a planar shape with respect to the holding member 641 that holds the rolling member 611. FIG. 9 is a perspective view showing a state where the first holding member 642 and the second holding member 643 are in a bent state with respect to the holding member 641 that holds the spreading member 611.

  FIG. 10 is an explanatory diagram illustrating a state where two sheets of paper T are sandwiched between the separating member 611 and the feeding roller 66 by the feeding operation of the feeding roller 66. In FIG. 11, the feeding process by the feeding roller 66 proceeds from the state shown in FIG. 10, the next sheet T <b> 2 is rolled by the rolling member 611, and the downstream end of the next sheet T <b> 2 is upstream of the rolling member 611. It is explanatory drawing which shows the state left on the side. FIG. 12 is an explanatory diagram illustrating a state in which the feeding process by the feeding roller 66 further proceeds from the state illustrated in FIG. 11 and the next sheet T2 starts to fall from the separating member 611 to the sheet material lift member 601 side. . In FIG. 13, the feeding process by the feeding roller 66 further proceeds from the state shown in FIG. 12, and the next sheet T <b> 2 falls from the separating member 611 to the sheet material lift member 601, and above the sheet material lift member 601. It is explanatory drawing which shows the state received by the receiving part 621.

The manual paper feed unit 64 is a sheet material feeding device that feeds the paper T, which is a sheet material, to the manual conveyance path La and further feeds it to the first conveyance path L1.
As shown in FIGS. 2 to 5, the manual sheet feeding unit 64 includes a manual tray 65, a sheet material lift member 601, a feeding roller 66, a holding member 641, a separating member 611, and a receiving unit 621. .

  The manual feed tray 65 is a sheet material placement unit on which the paper T before being fed is placed. The manual feed tray 65 is connected to the case body BD so as to be rotatable at a lower end (downstream end portion) located on the feeding roller 66 side. The manual feed tray 65 can be opened to the right side of the apparatus main body M as shown in FIG. By placing the manual feed tray 65 in an open state, the paper T can be placed. In a position where the manual feed tray 65 is fully opened, as shown in FIG. 2, the manual feed tray 65 is at an angle suitable for the placement of the paper T by a stay (metal fitting) 631 connected to the case body BD (see FIG. 2). Maintained.

As shown in FIGS. 2 to 6, the sheet material lift member 601 is disposed on the downstream end side of the manual feed tray 65. More specifically, as shown in FIG. 6, the sheet material lift member 601 is disposed on the lower surface side on the downstream side of the paper T placed on the manual feed tray 65. The sheet material lift member 601 is connected to the manual feed tray 65 so as to be rotatable about a support pin 603 at the upstream end 602 thereof. The sheet material lift member 601 rotates up and down as shown by an arrow R1 in FIG. 6 with the support pin 603 as a fulcrum.
The sheet material lifting member 601 moves up and down at the downstream end 604 to lift the downstream end of the paper T and lowers the downstream end of the paper T by the vertical rotation shown by the arrow R1 in FIG. To descend.

The state shown in FIG. 6 is a state in which the downstream end 604 of the sheet material lift member 601 is lowered to the lowest position.
The sheet material lift member 601 is capable of feeding by the feed roller 66 by pressing the downstream end of the paper T against the feed roller 66 by the rise of the downstream end 604 indicated by the arrow R2 in FIG. To do.

  The feeding roller 66 can be disposed opposite to the upper surface of the sheet material lift member 601. More specifically, as shown in FIG. 6, the feeding roller 66 is disposed at a position facing the upper surface of the downstream end 604 of the sheet material lift member 601. As shown in FIG. 7, the feeding roller 66 feeds the paper T by rotating the feeding roller 66 while abutting the upper surface of the paper T lifted by the sheet material lifting member 601.

  The spreading member 611 has a thin flat plate shape and is held on the surface of the holding member 641. The holding member 641 is a member attached to the housing of the apparatus main body M. As shown in FIG. 6, the holding member 641 includes a first holding member 642 that holds a rolling member 611 on the surface thereof, and a second holding member 643 that is connected to the lower end portion of the first holding member 642. I have. The second holding member 643 is a member extending from the lower end portion of the first holding member 642 to the vicinity of the downstream end portion 604 of the sheet material lift member 601.

As shown in FIGS. 8 and 9, the lower end portion of the first holding member 642 and the upper end portion of the second holding member 643 are rotatably connected by a pivot 645. The pivot 645 hinge-couples the first holding member 642 and the second holding member 643 so that they can be bent.
FIG. 8 shows a state where the surface of the first holding member 642 and the surface of the second holding member 643 are connected in a substantially planar shape. FIG. 9 shows a state where the surface of the first holding member 642 and the surface of the second holding member 643 are bent.
The holding member 641 is configured to generate an urging force in a direction in which the whirling member 611 approaches the feeding roller 66 when attached to the housing of the apparatus main body M.

  In a state where the holding member 641 is attached to the apparatus main body M, the surface of the separating member 611 held on the surface of the first holding member 642 forms a paper pressing surface 612 that circumscribes or is close to the feeding roller 66. As shown in FIG. 10, the separating member 611 is disposed on the downstream side of the sheet material lift member 601 so that the sheet T fed from the sheet material lift member 601 is pressed against the sheet feed roller 66 by the feed roller 66. Be placed. This separating member 611 uses a difference in frictional force acting on the front and back of the paper T to spread a bundle of paper T sandwiched between the feeding rollers 66 one by one.

  As shown in FIG. 6, a guide plate 651 is attached to the second holding member 643 of the holding member 641. The guide plate 651 has a curved shape that guides the downstream end of the paper T to be fed between the feed roller 66 and the separating member 611.

  As shown in FIG. 6, the guide plate 651 fills the gap between the lowered downstream end 604 of the sheet material lift member 601 and the lower end of the separating member 611, and when the sheet material lift member 601 is raised and lowered, The sheet T is prevented from being sandwiched between the downstream end 604 of the sheet material lifting member 601 and the lower end of the separating member 611. The guide plate 651 has flexibility, is formed of a film sheet that forms a convex curved shape on the sheet material lift member 601 side, and the paper T is easy to slip.

  As shown in FIG. 6, the receiving portion 621 is disposed on the upstream side of the rolling member 611. The receiving portion 621 receives the downstream end portion of the paper T that has been rolled up by the winding member 611 and remains on the upstream side of the winding member 611.

  More specifically, the receiving portion 621 receives and supports the downstream end portion of the paper T that falls from the separating member 611 toward the sheet material lift member 601 due to the separation by the separating member 611 in the middle of the guide plate 651. In other words, the receiving portion 621 is a stopper that supports the paper T falling from the separating member 611 at a height position in the middle of the guide plate 651 and stops the paper T from dropping.

  In the present embodiment, as shown in FIGS. 4 and 5, the receiving portion 621 is formed in a tongue shape extending upward from the lower end side of the guide plate 651, and receives the paper T at the upper end edge thereof. . Moreover, the receiving part 621 is formed in the shape of a tongue piece from the flexible film sheet mentioned above. Specifically, the receiving portion 621 is formed by cutting (raising) a part of the guide plate 651 which is a film sheet larger than the receiving portion 621 into a tongue shape. Therefore, the receiving portion 621 is formed integrally with the guide plate 651.

As shown in FIG. 8, the receiving portion 621 formed integrally with the guide plate 651 protrudes from the guide plate 651 when the first holding member 642 and the second holding member 643 extend straight. Absent.
On the other hand, the 2nd holding member 643 which comprises the holding member 641 has the press protrusion 647, as shown in FIG. The pressing protrusion 647 is a protrusion that presses the receiving portion 621 toward the sheet material lift member 601 when the second holding member 643 is bent with respect to the first holding member 642.

In other words, the pressing protrusion 647 moves in a direction in which the first holding member 642 of the holding member 641 moves away from the feeding roller 66 when the whirling member 611 is pressed by the feeding roller 66, and the state shown in FIG. In the state where the first holding member 642 and the second holding member 643 are bent, the receiving portion 621 is configured to be pressed.
The receiving portion 621 formed integrally with the guide plate 651 is positioned in a state where the receiving portion 621 protrudes toward the sheet material lift member 601 by pressing by the pressing protrusion 647.

  Next, the feeding operation of the paper T in the manual paper feeding unit 64 will be described with reference to FIGS. 6 and 7 and FIGS. 10 to 13. The peripheral surface of the feeding roller 66 and the sheet pressing surface 612 of the separating member 611 are always pressed directly or via the sheet T. However, for convenience of illustration, in some drawings, the feeding roller 66 is pressed. This is shown in a state where the peripheral surface of the paper and the sheet pressing surface 612 of the separating member 611 are not pressed against each other.

Before the feeding operation is started, the sheet material lift member 601 is in a state where its downstream end 604 is lowered to the lowest position as shown in FIG.
When the feeding operation is started, as shown in FIG. 7, the feeding roller 66 is rotationally driven in the direction of the arrow R5, and the downstream end 604 of the sheet material lift member 601 is lifted, so that the sheet The downstream end of the paper T placed on the material lift member 601 is pressed by the feeding roller 66.

  Furthermore, when the feeding of the paper T by the feeding roller 66 proceeds and the paper T pressed by the feeding roller 66 is fed between the separating member 611 and the feeding roller 66 by the rotation of the feeding roller 66, As shown in FIG. 10, the downstream end 604 of the sheet material lift member 601 descends, and the sheet material lift member 601 returns to the initial position before starting feeding.

  Then, as shown in FIG. 10, when the two papers T <b> 1 and T <b> 2 are overlapped by feeding by the feeding roller 66 and are sent between the feeding member 611 and the feeding roller 66, As shown in FIG. 11, the lower sheet T2 is left on the upstream side of the separating member 611, and only the upper sheet T1 that is in direct contact with the feeding roller 66 is conveyed downstream. The

  Then, when the feeding by the feeding roller 66 further proceeds from the state shown in FIG. 11, the downstream end of the lower sheet T2 left on the upstream side of the separating member 611 due to the separation by the separating member 611 is the upper side. As the sheet T1 is fed downstream of the feed roller 66, the attractive force due to friction with the upper sheet T1 gradually decreases. Therefore, as shown in FIG. 12, the downstream end portion of the lower sheet T2 is gradually retracted toward the sheet material lift member 601, but is supported by the receiving portion 621. It is difficult to retreat to the 601 side.

  As shown in FIG. 13, even when the upstream end of the upper sheet T1 is separated from the downstream end of the lower sheet T2, the downstream end of the lower sheet T2 is not the receiving portion. It is received and supported by 621. For this reason, the downstream end of the lower sheet T2 is less likely to be repelled by the upstream end of the upper sheet T1, or be repelled by the guide plate 651 during the fall. Accordingly, it is possible to suppress the occurrence of the “sheet material back phenomenon” due to the upstream edge of the sheet T1 fed first and the bounce to the guide plate 651.

According to the manual sheet feeding unit 64 of the present embodiment described above, for example, the following effects are achieved.
The manual paper feed unit 64 of the present embodiment is a sheet material feeding device that feeds the paper T, and is placed on the manual tray 65 on which the paper T before being fed is placed, and the manual tray 65. A sheet material lift member 601 that is disposed on the lower surface side of the downstream side of the sheet T to be lifted so as to lift the downstream end of the sheet T and descends to lower the downstream end of the sheet T; A feed roller 66 that can be disposed opposite to the upper surface of the lift member 601, and feeds the paper T by rotating the feed roller 66 in contact with the upper surface of the paper T lifted by the sheet material lift member 601. A sheet feeding roller 66 and a sheet T that is pressed between the sheet feeding roller 66 and a sheet member 611 that separates a bundle of sheets T one by one; Thatched member 6 Includes a receiving portion 621 for receiving the downstream end of the fielded by paper T remaining on the upstream side of the separating member 611 by 1, a.

Therefore, according to the present embodiment, when the paper T is fed, the downstream end portion of the paper T that has been rolled up by the paper-rolling member 611 and remains on the upstream side of the paper-rolling member 611 is separated from the paper-rolling member 611 by the sheet material lift member 601. When falling to the side, it is received by the receiving portion 621 in the middle of dropping.
Therefore, the next paper T that has been rolled up by the winding member 611 and left on the upstream side is flipped by the upstream end of the previous paper T that has been rolled up by the winding member 611 and fed downstream, and the like. A phenomenon of retreating upstream (sheet material back phenomenon) can be suppressed.
Further, according to the present embodiment, as a means for preventing the next sheet T from retreating to the upstream side, a trailing end stopper that abuts the upstream end of the retreated sheet T is not used. The size of the sheet material to be performed is not limited, and can correspond to sheet materials of various sizes.

  Further, in the manual sheet feeding portion 64 of the present embodiment, the receiving portion 621 is formed in a tongue shape from a flexible film sheet. Therefore, the receiving portion 621 can be easily formed, and an increase in manufacturing cost due to the addition of the manual sheet feeding portion 64 can be suppressed.

  In the present embodiment, the receiving portion 621 is formed by cutting a part of a film sheet larger than the receiving portion 621 into a tongue shape. Therefore, by using the guide plate 651 as a large film sheet, an increase in the number of components can be suppressed.

  In the present embodiment, a holding member 641 that holds the rolling member 611 is further provided, and the holding member 641 has a pressing protrusion 647 that presses the receiving portion 621 toward the sheet material lift member 601. Therefore, assuming that the receiving portion 621 is formed of a flat film sheet, the pressing portion 647 has a protruding shape suitable for receiving the paper T by the pressing by the pressing protrusion 647.

As mentioned above, although preferred embodiment was described, this invention can be implemented with a various form, without being limited to embodiment mentioned above.
For example, the sheet material feeding device of the present invention is applied to the manual paper feed unit 64 in the embodiment, but is not limited to this, and can be applied to, for example, a document conveying device.

In the embodiment, when the first holding member 642 holding the separating member 611 rotates with respect to the second holding member 643, the feeding roller 66 and the separating member 611 are configured to be able to approach or separate from each other. However, it is not limited to this. For example, the feeding roller 66 and the separating member 611 may be configured to be close to or away from each other by the parallel movement of the first holding member 642.
In the present embodiment, the copier 1 capable of color printing is described as the image forming apparatus. However, the present invention is not limited to this, and the image forming apparatus may be a monochrome copier, a printer, a facsimile, or a complex machine thereof. May be.

  DESCRIPTION OF SYMBOLS 1 ... Copy machine (image forming apparatus), 64 ... Manual feed part (sheet material feeding apparatus), 65 ... Manual feed tray (sheet material mounting part), 66 ... Feed roller, 601 ... Sheet Material lifting member, 611... Scattering member, 621... Receiving portion, 641 .. holding member, 642... First holding member, 643... Second holding member, 647. BD: Case body, GK: Image forming section, T: Paper (sheet material)

Claims (6)

A sheet material feeding device for feeding a sheet material,
A sheet material placement section on which the sheet material before being fed is placed;
It is arranged on the lower surface side of the downstream side of the sheet material placed on the sheet material placement portion, and rises to lift the downstream end portion of the sheet material and descends to lower the downstream end portion of the sheet material. A seat material lift member;
A feeding roller that can be disposed opposite to the upper surface of the sheet material lift member, and rotating the sheet material while rotating the sheet roller while contacting the upper surface of the sheet material lifted by the sheet material lift member. A feed roller for feeding,
A sheeting member that is arranged to press the sheet material with the feeding roller and spreads a bundle of sheet materials one by one;
A receiving portion that is disposed on the upstream side of the rolling member and receives the downstream end of the sheet material that has been rolled up by the winding member and left on the upstream side of the rolling member;
An upper end edge of the receiving member is a sheet material feeding device arranged below the upper surface of the rolling member.   The upper end edge of the receiving portion does not contact the downstream end portion of the sheet material sent out by the feeding roller, but is rolled by the separating member and the downstream end of the sheet material remaining on the upstream side of the separating member The sheet material feeding device according to claim 1, wherein the sheet material feeding device receives the portion. A guide member having a shape for guiding the downstream end of the sheet material to be fed between the feeding roller and the winding member;
The sheet material feeding device according to claim 1, wherein the receiving portion receives a downstream end portion of the sheet material remaining on the upstream side of the winding member at a position in the height direction of the guide member. The sheet material feeding device according to any one of claims 1 to 3, wherein the receiving portion is formed in a tongue-like shape from a flexible film sheet. The sheet receiving apparatus according to claim 4, wherein the receiving portion is formed by cutting a part of the film sheet larger than the receiving portion into a tongue shape. A sheet material feeding device according to any one of claims 1 to 5,
An image forming apparatus comprising: an image forming unit that forms an image on the sheet material fed by the sheet material feeding device.

Images