JP4711346B2 - Sheet conveying apparatus and image forming apparatus provided with the same - Google Patents

Description

  The present invention relates to a sheet conveying apparatus that separates and feeds sheets stored in a stacked state one by one, and an image forming apparatus including the sheet conveying apparatus.

  In an image forming apparatus such as a copying machine, a printer, or a facsimile, a sheet conveying device is used to supply a sheet to an image forming unit. Among these sheet conveying apparatuses, a plurality of sheets are stored in a sheet feeding cassette in a stacked state, and are fed and conveyed by a sheet feeding roller in order from the top sheet among the plurality of sheets in the cassette. Yes.

  In such a sheet conveying apparatus, conveyance failure may occur due to static electricity. In other words, the upper and lower sheets in the sheet feeding cassette may stick to each other due to static electricity, or the sheets may be rubbed against each other due to continuous sheet feeding, and charges may accumulate on the sheet surface. When a charged sheet is fed by a sheet feeding roller, conveyance failure such as double feeding of two or more sheets or jam (paper jam) occurs.

  In order to eliminate such a conveyance failure, for example, Patent Document 1 proposes using an electrostatic actuator. The electrostatic actuator has a plurality of strip-shaped electrodes arranged at right angles to the sheet feeding direction, and is arranged to face the leading end side of the sheet to be fed. When a sheet is fed, a voltage having a different polarity is applied to adjacent electrodes by a driving power source, and the polarity is sequentially switched. As a result, the uppermost sheet can be attracted to the electrostatic actuator by electrostatic force and reliably separated from the next sheet and fed one by one.

JP-A-8-81074

  However, according to the above-described Patent Document 1, there is a problem that the configuration for reliably separating the uppermost sheet from the next sheet and feeding the sheets one by one is complicated, and the control is complicated. That is, the electrostatic actuator has a structure in which a plurality of strip-like electrodes are disposed on an insulating substrate, and the structure becomes complicated. Further, since it is necessary to apply different polarities to adjacent electrodes and to control these polarities in synchronization with the paper feed timing of the paper feed roller, there is a problem that the control is complicated.

  Accordingly, the present invention provides a sheet conveying apparatus and an image forming apparatus including the sheet conveying apparatus that can reliably separate and feed sheets one by one while having a simple configuration and no complicated control. It is for the purpose.

  The invention according to claim 1 relates to a sheet conveying apparatus that feeds and conveys a sheet. A sheet conveying apparatus according to the present invention includes a non-grounded sheet storage member that stores a plurality of sheets in a stacked state, and a top sheet among the plurality of sheets in the sheet storage member. A holding member disposed at a position, a sheet feeding roller which is brought into contact with the sheet disposed at the sheet feeding position by the retaining member and feeds the uppermost sheet by friction caused by rotation, and is disposed at the sheet feeding position. A conductive sheet separating member disposed above the uppermost sheet, and the sheet separating member is disposed so as to face the uppermost sheet with a predetermined gap and is grounded. It is characterized by being kept in a state.

  According to a second aspect of the present invention, there is provided the sheet conveying apparatus according to the first aspect, wherein the predetermined gap is caused by a reverse polarity charge induced in the sheet separating member by the uppermost sheet in a charged state. The sheet separating member is set so as to be drawn toward the sheet separating member and separated from the next sheet.

  The invention according to claim 3 is the sheet conveying apparatus according to claim 2, wherein the predetermined gap is set so that the sheet drawn toward the sheet separating member does not contact the sheet separating member. It is characterized by.

  A fourth aspect of the present invention relates to an image forming apparatus including an image forming unit that forms an image on a sheet, and a sheet conveying device that supplies the sheet to the image forming unit. The image forming apparatus according to the present invention is characterized in that the sheet conveying device is the sheet conveying device according to any one of claims 1 to 3.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the fourth aspect, the sheet separating member is formed in a part of a guide member for guiding the conveyance of the sheet.

  According to a sixth aspect of the present invention, in the image forming apparatus according to the fourth aspect, the sheet separating member is provided in a sheet re-feeding path through which the sheet passes in order to form an image once again on the image-formed sheet. It is characterized by being partly configured.

  According to the first aspect of the present invention, the sheet storage member that stores the sheet is in a non-grounded state, while the conductive sheet separating member that faces the uppermost sheet is in the grounded state. When the sheet is charged, this charge induces a charge having a polarity opposite to that of the uppermost sheet, on the sheet separating member. Due to the reverse polarity charge induced in the sheet separating member, the uppermost sheet is attracted to the sheet separating member side to be in an unstable state and easily separated from the next sheet. In this state, when the paper feed roller is rotated, the uppermost sheet is separated from the next sheet and only one sheet is fed.

  The second aspect prevents the predetermined gap from being too wide. That is, if the predetermined gap is too wide, the electrostatic force acting between the uppermost sheet and the sheet separating member is small, and the uppermost sheet cannot be sufficiently separated from the next sheet. Therefore, according to the second aspect of the present invention, the uppermost sheet is drawn toward the sheet separating member by the reverse polarity charge induced in the sheet separating member by the uppermost sheet in the charged state. By being set to be separated, the uppermost sheet is reliably separated from the next sheet.

  The third aspect prevents the predetermined gap from being too narrow. That is, when the predetermined gap is too narrow, the electrostatic force acting between the uppermost sheet and the sheet separating member is large, and the uppermost sheet is sufficiently separated from the next sheet, but is in contact with the sheet separating member. Will end up. Therefore, according to the second aspect of the present invention, the uppermost sheet is drawn toward the sheet separating member by the reverse polarity charge induced in the sheet separating member by the uppermost sheet in the charged state. Even when separated, the sheet separation member is set so as not to contact. This prevents the uppermost sheet from being rubbed against the sheet separating member during sheet feeding.

  According to the fourth aspect of the present invention, since the image forming apparatus includes the above-described sheet conveying device, the sheet conveying device can reliably supply one sheet to the image forming unit. Thus, it is possible to reliably form an image on each sheet. That is, it is possible to eliminate unnecessary interruption of the image forming operation due to a problem of performing image formation on the double-fed sheets or a paper jam due to poor sheet separation.

  According to the invention of claim 5, since the sheet separating member is formed in a part of the sheet conveying guide, it is not necessary to provide the sheet separating member individually, and the configuration can be simplified correspondingly.

  According to the invention of claim 6, since the sheet separating member is formed in a part of the sheet re-conveying guide, it is not necessary to provide the sheet separating member individually, and the configuration can be simplified correspondingly. .

  Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. In addition, in each drawing, the member etc. which attached | subjected the same code | symbol are the same structures, The duplication description about these shall be abbreviate | omitted suitably. Moreover, in each drawing, members and the like that are not necessary for the description are omitted as appropriate.

<Embodiment 1>
An image forming apparatus 1 and a sheet conveying apparatus 2 according to the present invention will be described with reference to FIGS. Among these, FIG. 1 is a perspective view of the overall appearance of the image forming apparatus 1 as viewed from the upper left obliquely upper side. FIG. 2 is a diagram schematically showing the internal structure of the image forming apparatus 1 as viewed from the left side. FIG. 3 is a perspective view of the image forming apparatus main body 4 in a state in which the paper feed cassette 3 is pulled out, as viewed from the upper left obliquely upper side. FIG. 4 is a perspective view of the sheet feeding cassette 3 in a state of being pulled out from the image forming apparatus main body 4 as viewed from the rear upper rear side on the right side. FIG. 5 is a perspective view of the vicinity of the paper feed roller 5 as viewed from the lower right side.

  As shown in FIG. 1, the entire image forming apparatus 1 is formed in a substantially rectangular parallelepiped shape surrounded by six surfaces: a front surface 1a, a left side surface 1b, a right side surface 1c, a back surface 1d, an upper surface 1e, and a bottom surface 1f. . The image forming apparatus includes an image forming apparatus main body 4 and a paper feed cassette 3 (sheet storage member). The paper feed cassette 3 is located on the lower side of the front surface 1a of the image forming apparatus main body 4 as shown in FIG. Furthermore, it can be inserted / removed in the front / rear direction with respect to the attachment / detachment opening 1g formed in the gate. An operation panel 7 having a display unit 6 is disposed on the front side and the right side of the upper surface 1 e of the image forming apparatus 1.

  As illustrated in FIG. 2, the image forming apparatus 1 includes a sheet transport unit 11 that feeds and transports a sheet P (a recording medium on which an image is formed, such as paper and a transparent film), and a toner on the transported sheet P. An image forming unit 12 that forms an image (image), a fixing unit 13 that fixes the image on the sheet P, a sheet discharge unit 14 that discharges the sheet P on which the toner image is fixed, and a sheet P on which the toner image is fixed And a sheet re-conveying unit 15 that supplies the image forming unit 12 to the image forming unit 12 again.

  Among these, in the sheet conveyance unit 11, the sheet feeding cassette 3, the sheet feeding roller 5, the feeding roller 16, the retard roller 17, the conveyance roller 18, the conveyance roller are arranged almost sequentially from the upstream side to the downstream side in the conveyance direction of the sheet P. 20, 21 and a pair of registration rollers 22 are arranged. A plurality of sheets P are stored in the sheet feeding cassette 3 in a stacked state. The paper feed cassette 3 will be described in detail later.

  As shown in FIG. 2, the uppermost sheet Pa (the uppermost sheet of the plurality of sheets) in the sheet feeding cassette 3 is pushed up by an intermediate plate 23 (holding member) to be described later and fed. The sheet is abutted against the paper roller 5 and disposed at the paper feed position M. The uppermost sheet Pa is fed downstream (in the direction of the arrow Kp) by friction due to the rotation of the paper feed roller 5 in the direction of the arrow R5. The fed sheet P is prevented from being double fed by the retard roller 17 and conveyed downstream by the feed roller 16. The sheet P is further conveyed toward the registration roller pair 22 by the conveyance roller 18 and the conveyance rollers 20 and 21. The sheet P is brought into contact with the stopped registration roller pair 22 to correct skewing, and then a toner image on the photosensitive drum 26 of the image forming unit 12 described later is transferred to the transfer nip T by the rotation of the photosensitive drum 26. The toner is supplied to the transfer nip portion T so as to match the timing at which the toner is conveyed.

  The sheet conveying unit 11 is also provided with an openable / closable manual feed tray 24. The manual feed tray 24 stands upright and constitutes a part of the front surface 1a of the image forming apparatus 1 in the closed state. On the other hand, in the open state shown in FIG. 2, the sheet P for manual feeding (not shown) can be set on the upper surface 24a with a gentle inclined posture. The set sheet P is conveyed downstream by a pair of manual feed rollers 25.

  The image forming unit 12 is provided with a photosensitive drum 26 as an image carrier. Further, around the photosensitive drum 26, a charging roller 27, an exposure device 28, a developing device 30, a transfer roller 31, a cleaning device 32, and the like are disposed in order from the upstream side along the rotation direction. The photosensitive drum 26 is rotationally driven at a predetermined process speed (circumferential speed) in the direction of arrow R26 by a driving means (not shown). The surface of the photosensitive drum 26 is uniformly charged to a predetermined polarity and potential by a charging roller 27. The surface of the photosensitive drum 26 after charging is subjected to exposure L based on image information from the exposure device 28, and the charge of the exposed portion is removed to form an electrostatic latent image. The electrostatic latent image is developed as a toner image with toner attached thereto by the developing device 30. A toner supply container 33 is disposed above the developing device 30 so as to supply toner into the developing device 30.

  The toner image formed by the developing device 30 is conveyed to the transfer nip T formed between the photosensitive drum 26 and the transfer roller 31 as the photosensitive drum 26 rotates. At this time, the sheet P is supplied from the registration roller pair 22 to the transfer nip portion T, and the toner image on the photosensitive drum 26 is transferred onto the sheet P by the transfer roller 31. After the toner image has been transferred, the toner remaining on the surface of the photosensitive drum 26 (transfer residual toner) is removed by the cleaning device 32 and used for the next image formation.

  On the other hand, the sheet P after the toner image is transferred is conveyed to the fixing unit 13. The fixing unit 13 is provided with a fixing roller 34 incorporating a heater (not shown) and a pressure roller 35 pressed against the fixing roller 34, and a fixing nip portion N is formed between the two rollers. ing. The sheet P that has been conveyed while carrying the unfixed toner image is nipped and conveyed at the fixing nip portion N, and at this time, the toner image is fixed on the surface by being heated and pressurized.

  The sheet P on which the toner image is fixed is conveyed to the sheet discharge unit 14 or the sheet reconveying unit 15 by switching the flapper 36. In the case of single-sided image formation, the sheet P on which the toner image is fixed is conveyed to the sheet discharge unit 14 and discharged onto the discharge tray 40 by the conveyance roller pair 37 and the discharge roller pair 38. Thereby, the image formation on the surface (one side) of one sheet is completed.

  On the other hand, in the case of double-sided image formation, the sheet P on which the toner image is fixed on the front surface (one surface) is switched after the trailing edge has passed through the flapper 36, and the conveyance roller pair 37, discharge By rotating the roller pair 38 in the reverse direction, the sheet is conveyed to the sheet re-conveying unit 15 while being reversed.

  The sheet reconveying unit 15 has a sheet reconveying guide 41. The sheet re-conveying guide 41 has an upper guide 42 and a lower guide 43 facing the upper guide 42 from below, and a sheet conveying path is formed between the two guides. On the sheet re-conveying guide 41, re-conveying roller pairs 44, 45, and 46 are disposed in order from the upstream side in the sheet re-conveying direction. The sheet P guided by the sheet re-conveying guide 41 and re-conveyed by the sheet re-conveying rollers 44, 45, 46, passes through the above-described conveying roller 18, the conveying rollers 20, 21, and the registration roller pair 22. The toner image is supplied to the image forming unit 12 where the toner image is also transferred to the back surface. Thereafter, after the toner image is fixed by the fixing unit 13, the sheet P is discharged onto the paper discharge tray 40 via the sheet discharge unit 14. As a result, image formation on both sides of one sheet P is completed.

  In the present embodiment, in the above-described image forming apparatus, the uppermost sheet Pa fed from the paper feed position M of the paper feed cassette 3 toward the downstream side is reliably separated and fed one by one. In this way, it is possible to prevent paper feeding defects such as double feeding and paper jams. Hereinafter, this point will be described in detail.

  As shown in FIG. 4, the sheet feeding cassette 3 has a front plate 50, a bottom plate 51, a left side plate 52, and a right side plate 53, and a plurality of stacked sheets P are accommodated among them. A storage space R is configured. In the storage space R, an intermediate plate 23 is swingably disposed. The intermediate plate 23 has a support shaft 54 projecting inward from the left plate 52 and the right plate 53 in the vicinity of the left and right end portions 23a on the rear end side (in FIG. 4, only the support shaft 54 of the left plate 52 is shown. ) So that it can swing. As a result, the front end 23b side of the intermediate plate 23 can move substantially in the vertical direction. A compression spring 55 (see FIG. 2) is disposed between the front end 23b side of the intermediate plate 23 and the bottom plate 51, and thereby the intermediate plate 23 is urged upward. That is, the holding plate that holds the uppermost sheet Pa at the sheet feeding position M is configured by the intermediate plate 23 and the compression spring 55 that biases the intermediate plate 23 upward. A left guide block 56 and a right guide block 57 are disposed between the front plate 50 and the front end 23 b of the middle plate 23. These guide blocks 56 and 57 are provided with leading edge restricting portions 56a and 57a for restricting the position of the leading edge of the sheet P set in the sheet feeding cassette 3, and for conveying the sheet P immediately after being fed upward in the conveying direction. Guides 56b and 57b are formed. Between the left and right guide blocks 56 and 57, the above-described retard roller 17 having a torque limiter (not shown) is disposed. When one sheet P is conveyed between the retard roller 17 and the feeding roller 16 by the torque limiter, the retard roller 17 is rotated in the conveying direction of the sheet P, while two or more sheets P are conveyed. In this case, the sheet is reversely rotated to return the sheet to the sheet feeding cassette 3 side. On the front end side of the outer surface of the right side plate 53, a swingable fan-shaped gear 60 having a support shaft 58 in the lower portion and a rotatable gear 61 engaged with the fan-shaped gear 60 are disposed. The gear 61 is engaged with a part of the image forming apparatus main body 4 when a plurality of stacked sheets P are set on the intermediate plate 23 and the paper feeding cassette 3 is inserted into the image forming apparatus main body 4. This rotation causes the sector gear 60 to swing and push down the intermediate plate 23. Thus, the sheet P lifted by the intermediate plate 23 does not come into contact with the paper feed roller 5 when the paper feed cassette 3 is inserted, so that the paper feed cassette 3 can be smoothly inserted into the predetermined body of the image forming apparatus main body 4. Can be pushed into the position. When the paper feed cassette 3 is disposed at a predetermined position, the engagement of the gear 61 with a part on the image forming apparatus main body 4 side is released, whereby the intermediate plate 23 is brought into a natural state and the compression spring is released. 55 is pushed upward. The pushed-up sheet P stops in a state where the uppermost sheet is in contact with the sheet feeding roller 5 on the image forming apparatus main body 4 side. The position of the uppermost sheet Pa at this time is the sheet feeding position M. The sheet cassette 3 described above is entirely ungrounded.

  As shown in FIG. 5, the paper feed roller 5 and the feed roller 16 are incorporated in a base member 62 to constitute a paper feed unit 63. In the drawing, the direction of the arrow Kp is the downstream side in the conveyance direction of the sheet P. The paper feeding unit 63 is attached to the image forming apparatus main body 4 side. The paper feed unit 63 has a bearing portion 64 that supports a shaft that rotatably supports the feed roller 16. The paper feed roller 5 is rotatably supported by a box-shaped support member 65 that is swingably supported by this shaft. The support member 65 is biased downward by a compression spring 66 interposed between the support member 65 and the base member 62 and is regulated by a stopper (not shown) to be positioned on the lower side. As a result, the paper feed roller 5 is positioned at a predetermined position while being biased downward. This predetermined position defines a paper feed position M when the uppermost sheet Pa in the paper feed cassette 3 is fed.

  The rotation is transmitted to the feed roller 16 and the feed roller 5 from a motor (not shown) on the image forming apparatus main body 4 side via a coupling 67, a drive gear 68, and the like. A guide portion 70 that is curved upward is formed on the distal end side of the base member 62. The guide unit 70 faces the conveyance guides 56b and 57b of the guide blocks 56 and 57 of the above-described sheet feeding cassette 3 shown in FIG. 4, and guides the sheet P immediately after feeding together with the conveyance guides 56b and 57b. .

  In the present embodiment, as shown in FIG. 2, the above-described lower guide 43 disposed above the sheet feeding cassette 3 mounted at a predetermined position with respect to the image forming apparatus main body 4 is provided with conductive sheet separation. It constitutes a member. As described above, the lower guide 43 constitutes the sheet re-conveying guide 41 together with the upper guide 42 as described above. The sheet re-conveying guide 41 is formed in a substantially flat shape, and is disposed from the rear side to the front side of the image forming apparatus body 4 and is inclined so that the front side (downstream side) is slightly higher. .

  The lower guide 43 is formed of a thin sheet metal. The width of the lower guide in the left-right direction is set wider than the sheet passing width (the width of the leading end) of the sheet P used for image formation, that is, the sheet P stored in the sheet feeding cassette 3. Further, the length of the lower guide 43 in the front-rear direction is slightly longer than the most upstream re-conveying roller pair 44 among the three re-conveying roller pairs 44, 45, 46 disposed in the sheet re-conveying unit 15. The length is set so as to start from the upstream side, extend toward the front side, and reach the vicinity of the conveying roller 18 at the tip. In other words, in the present embodiment, the uppermost sheet Pa in the sheet feeding cassette 3 is formed to have a size that covers almost the whole except for a part on the rear end side (left side in FIG. 2).

  The lower guide 43 is disposed so as to face the uppermost sheet Pa disposed at the sheet feeding position M via a predetermined gap A above the uppermost sheet Pa. Further, the lower guide 43 is electrically connected to a metal main body frame (not shown) constituting the framework of the image forming apparatus main body 4. The main body frame is grounded. That is, the lower guide 43 is grounded via the main body frame. On the other hand, as described above, the paper feed cassette 3 is not grounded.

  Here, the predetermined gap A between the uppermost sheet Pa at the sheet feeding position M and the lower guide 43 will be described.

  In the present embodiment, as described above, the paper feed cassette 3 is in a non-grounded state. Therefore, for example, when storing a plurality of sheets P in the sheet feeding cassette 3, when the upper and lower sheets P are stuck together due to static electricity, or when feeding, the uppermost sheet Pa to be fed and the next sheet The upper and lower sheets may stick together due to static electricity generated by friction with the sheet Pb. In such a case, feeding failure such as double feeding or paper jam occurs during feeding.

  On the other hand, the lower guide 43 disposed so as to face the sheet Pa disposed at the sheet feeding position M is grounded. Therefore, for example, when the uppermost sheet Pa is charged, a charge having a polarity opposite to that of the charged polarity is induced in the lower guide 43, and an electric charge is generated between the lower guide 43 and the uppermost sheet Pa. Attraction is generated. By this attractive force, the uppermost sheet Pa is pulled up toward the lower guide 43 and is separated from the next sheet Pb.

  If the above-described electrical attractive force, that is, the electrical attractive force acting between the lower guide 43 and the uppermost sheet Pa is too small, the uppermost sheet Pa is sufficiently separated from the next sheet Pb. I can't. Here, “cannot be separated sufficiently” means that it cannot be separated to the extent that double feed does not occur. On the other hand, when the electrical attraction between the two is too large, the uppermost sheet Pa can be sufficiently separated from the next sheet Pa, but the uppermost sheet Pa is in contact with the lower guide 43. When the paper is fed, the uppermost sheet Pa may be rubbed against the lower guide 43.

  Here, as an element that affects the magnitude of the electric attractive force between the lower guide 43 and the uppermost sheet Pa, the distance between the lower guide 43 and the uppermost sheet Pa, the lower guide 43 The size, the arrangement position, the amount of charge of the uppermost sheet Pa, and the like can be considered.

  Therefore, in the present embodiment, paying attention to the distance between the lower guide 43 and the uppermost sheet Pa among them, the distance between them is sufficiently separated from the next sheet Pb. In addition, the distance is set such that the uppermost sheet Pa does not come into contact with the lower guide 43. Such a distance is defined as a predetermined gap A.

  Further, the predetermined gap A is simply the distance between the lower guide 43 and the uppermost sheet Pa when they are substantially parallel. In the present invention, it is preferable that the uppermost sheet Pa is separated from the next sheet Pb immediately upstream of the sheet feed roller 5. It is narrow on the upstream side of the paper roller 5 and wide on the side far from the paper feed roller 5. In such a case, the predetermined gap A is a distance between the lower guide 43 and the uppermost sheet Pa in the vicinity of the paper feed roller 5.

  In the above description, the case where the entire lower guide 43 constitutes the sheet separating member has been described, but the present invention is not limited to this. For example, a portion of the lower guide 43 corresponding to the upstream side of the sheet feeding roller 5 is protruded downward, and the protruding portion is brought close to the uppermost sheet Pa so that the attractive force at the protruding portion is increased. Alternatively, the attractive force on the uppermost sheet Pa may be adjusted by increasing the size, or conversely, by forming a part of the lower guide 43 with resin so that the attractive force of the resin portion is reduced. .

  In the above description, when the lower guide 43 has a large force to attract the uppermost sheet Pa and the uppermost sheet Pa contacts the lower guide 43, the sheet Pa is rubbed against the lower guide 43 during feeding. Actually, when the charged sheet Pa comes into contact with the lower guide 43, this charge escapes through the lower guide 43 and the main body frame, so the charge of the sheet Pa immediately disappears. The sheet Pa is separated from the lower guide 43. Therefore, even if it is rubbed, it is a very short time, and thus the adverse effects caused by this can be minimized. As described above, even when the uppermost sheet Pa is rubbed against the lower guide 43, the effect of reliably separating the uppermost sheet Pa from the next sheet Pb can be obtained.

  In the above description, the case where the sheet separating member is configured by the lower guide 43 in the sheet reconveying unit 15 has been described as an example. However, for example, the image forming apparatus does not have a sheet reconveying unit. If a lower guide is provided as a part of the sheet conveying unit for conveying the sheet P to the image forming unit 12 immediately above the sheet feeding cassette 3, the sheet separating member is formed by the lower guide. You may make it comprise. Further, the sheet re-conveying unit and the lower guide of the sheet conveying unit do not also serve as the sheet separating member, but a dedicated sheet separating member may be disposed above the uppermost sheet Pa. In this case, since the degree of freedom regarding the shape and size of the sheet separating member and the arrangement position is greatly increased, the sheet separating member that exhibits the desired performance can be configured relatively easily. Become.

  In the above description, the case where the sheet conveying apparatus according to the present invention is disposed in the image forming apparatus has been described as an example. However, the sheet conveying apparatus according to the present invention is not limited to this, and performs processing on the sheet. It is also possible to apply to a sheet processing apparatus for conveying a sheet to the sheet processing unit. Here, examples of the sheet processing unit include a sorter for sorting sheets, a stapler for stapling, a punching device for punching, a folding device for folding.

FIG. 3 is a perspective view of the entire appearance of the image forming apparatus as viewed from the upper left obliquely upper side. FIG. 2 is a diagram schematically showing an internal structure of the image forming apparatus as viewed from the left side. FIG. 3 is a perspective view of the image forming apparatus main body in a state in which the paper feed cassette is pulled out, as viewed from the upper left obliquely upper side. FIG. 3 is a perspective view of the sheet feeding cassette in a state where the sheet feeding cassette is pulled out from the image forming apparatus main body, as viewed from the right rear and obliquely upward. FIG. 6 is a perspective view of the vicinity of a sheet feeding roller as viewed from the lower right side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Sheet conveying apparatus, 3 ... Paper feed cassette (sheet storage member), 4 ... Image forming apparatus main body, 5 ... Paper feed roller, 11 ... Sheet conveying section, 12 ... ... Image forming section, 13... Fixing section, 14... Sheet discharge section, 15... Sheet re-conveyance section, 23... Intermediate plate (holding member), 41. Sheet separating member), 55... Compression spring (holding member), A... Predetermined gap, M .. feeding position, P .. sheet, Pa .. top sheet, Pb. Sheet of,

Claims (6)

In a sheet conveying apparatus that feeds and conveys a sheet,
A non-grounded sheet storage member that stores a plurality of sheets in a stacked state; and
Among the plurality of sheets in the sheet storage member, a holding member that arranges the uppermost sheet at a predetermined sheet feeding position;
A paper feed roller that is brought into contact with the uppermost sheet disposed at the paper feeding position by the holding member and feeds the uppermost sheet by friction caused by rotation;
A conductive sheet separating member disposed above the uppermost sheet disposed at the sheet feeding position;
The sheet separating member is disposed so as to face through the predetermined gap from the uppermost sheet and is kept in a grounded state.
A sheet conveying apparatus. The predetermined gap is such that the uppermost sheet is drawn toward the sheet separating member and separated from the next sheet by the reverse polarity charge induced in the sheet separating member by the charged uppermost sheet. Set to
The sheet conveying apparatus according to claim 1. The predetermined gap is set so that the sheet drawn toward the sheet separating member does not contact the sheet separating member.
The sheet conveying apparatus according to claim 2. An image forming apparatus comprising: an image forming unit that forms an image on a sheet; and a sheet conveying device that supplies the sheet to the image forming unit.
The sheet conveying apparatus is the sheet conveying apparatus according to any one of claims 1 to 3.
An image forming apparatus. The sheet separating member is formed by a part of a sheet conveyance guide constituting a sheet conveyance path.
The image forming apparatus according to claim 4. The sheet separating member is formed once by a part of a sheet re-conveying guide constituting a sheet re-conveying path for performing image formation again on the image-formed sheet.
The image forming apparatus according to claim 4.

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