Sheet conveying apparatus and image forming apparatus

An image forming apparatus including a sheet conveying portion which conveys a sheet to be formed with an image, and an abutment member which is abutted by the tip end of a sheet conveyed by the sheet conveying portion, and movable to a first attitude of being abutted by the tip end of the sheet being conveyed, and to a second attitude of allowing passage of the sheet and being in the state of abutting the surface of the sheet, wherein the abutment member in the second attitude abuts a part which is outside an image forming region and on the sheet surface having the image forming region in a central part in a width direction orthogonal to a sheet conveying direction.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image forming apparatus which forms an image on a sheet.

2. Description of the Related Art

In the related art, image forming apparatuses, such as a copying machine, a printer and a facsimile machine, are each provided with an image forming portion and a sheet conveying apparatus for conveying a sheet to the image forming portion by means of conveying rollers. Further, the sheet conveying apparatus may include an abutment member, which is provided in a sheet conveying path, and applied with a force in a direction opposite to a sheet conveying direction, and also moves from a position of being pressed by a sheet being conveyed to abut the sheet against the applied force to a position of allowing passage of the sheet while being in contact with the sheet.

Incidentally, in the conventional image forming apparatus, when a conveying roller is formed in taper shape or alignment of the conveying rollers is displaced, or in some other case, a sheet may be skew-fed during conveyance of the sheet. Especially when a sheet is fed from a cassette or a plurality of sheets is separated so as not to be simultaneously conveyed, skew feeding tends to occur since a roller width is small and the sheet cannot be sufficiently held for rotation. When the sheet is skew-fed as thus described, the accuracy in image forming position deteriorates.

Thereat, in the conventional image forming apparatus, a skew correcting portion is provided in the sheet conveying apparatus, and the accuracy in image forming position is sought to be improved by correcting skew feeding of the sheet in this skew correction portion. As such a skew correcting portion, for example, there is one provided with a shutter applied with a force by a spring or the like in a direction opposite to the sheet conveying direction, and makes this shutter abut the tip end of a sheet (see U.S. Pat. No. 6,011,948).

In the skew correcting portion using such a shutter, in the case of correcting skew feeding of a sheet, the sheet being skew-fed is first abutted by the shutter. Herein, when the sheet is being skew-fed, one of both ends of the sheet being skew-fed abuts the shutter. At this time, since the shutter being applied with a force by the spring or the like cannot move, the sheet in the end abuts the shutter as the entire tip end thereof follows a generating line of the shutter. Following the generating line of the shutter as thus described can correct skew feeding of the sheet.

Further, when the tip end of the sheet follows the generating line of the shutter as thus described, the shutter can then be rotated against the spring or the like applying the force to the shutter due to the stiffness of the sheet, so that the sheet can pass while rotating the shutter. In addition, for obtaining a favorable output image, it is important to correct skew feeding of a sheet before an image is transferred to the sheet in the image forming portion. Further, a position where the correction is made is more favorably closer to the image forming portion. Incidentally, in such conventional sheet conveying apparatus and image forming apparatus provided with this sheet conveying apparatus, when a sheet passes while rotating the shutter, the shutter comes to press the sheet surface. Herein, the stronger the applied force that is applied to the shutter, the more the skew correcting ability improves, but when the applied force is thus made stronger, a pressing force that is applied to the sheet by the shutter increases.

Then, when the pressing force that is thus applied to the sheet increases, the surface of the sheet may be damaged. Especially, glossy paper or the like with a coated surface, which is used with the recent colorization, tends to be damaged on the surface, and a damage that occurs during passage through the shutter appears when a toner image is formed. Further, depending on a type of sheet, charging may occur due to friction that occurs during passage through the shutter, thereby to prevent accurate formation of a toner image. As thus described, although increasing the applied force that is applied to the shutter improves the skew correcting ability, it may cause deterioration in quality of an image formed on the sheet.

It should be noted that, other than the shutter, the conventional sheet conveying apparatus is provided with a conveying path switching member which switches the sheet conveying path as the abutment member that moves from a position of being pressed by a sheet being conveyed to abut the sheet to a position of allowing passage of the sheet while being in contact with the sheet surface. Also at the time of passage through such a conveying path switching member, although increasing an applied force of the conveying path switching member can reliably switch the sheet conveying path, the sheet may be damaged at the time of passage thereof, to cause deterioration in quality of an image formed on the sheet.

SUMMARY OF THE INVENTION

Thereat, the present invention was made in view of such a current condition, and provides a sheet conveying apparatus and an image forming apparatus which allow passage of a sheet without causing deterioration in image quality. The present invention is an image forming apparatus including a sheet conveying portion which conveys a sheet to be formed with an image, and an abutment member which is abutted by the tip end of a sheet conveyed by the sheet conveying portion, and movable to a first attitude of being abutted by the tip end of the sheet being conveyed, and to a second attitude of allowing passage of the sheet and being in the state of abutting the surface of the sheet, wherein the abutment member in the second attitude abuts a part which is outside an image forming region and on the sheet surface having the image forming region in a central part in a width direction orthogonal to a sheet conveying direction. As in the present invention, when located in the passage position, the abutment member is made to abut a part which is outside an image forming region and in each end portion of the sheet surface having the image forming region in a central part in a width direction, allowing passage of the sheet without causing deterioration in image quality.

DESCRIPTION OF THE EMBODIMENTS

In the following, modes for implementing the present invention are described with reference to the drawings.FIG. 1is a view which illustrates a schematic configuration of a color laser printer as an example of an image forming apparatus provided with a sheet conveying apparatus according to a first embodiment of the present invention. InFIG. 1, a color laser printer200and a color laser printer body (hereinafter referred to as apparatus body)201are provided. This apparatus body201includes an image forming portion202, a paper feeder203which feeds a sheet S to the image forming portion202, a fixing portion110, and the like.

The image forming portion202is provided with cylindrical photosensitive drums101(101ato101d), primary chargers102(102ato102d), and development devices104(104ato104d) integrated with a toner cartridge. Further, the image forming portion202is provided with an endless intermediate transfer belt106where toner images of four colors, having been sequentially formed by the photosensitive drum101, are sequentially primarily transferred, and secondary transfer rollers109which secondarily transfer to the sheet S the toner image having been primarily transferred to the intermediate transfer belt106. It is to be noted that laser scanners103(103ato103d) irradiate the photosensitive drums101with laser light L emitted according to an image signal.

The paper feeder203is provided with cassettes111,112which accommodate the sheets S and are attachable and detachable to and from the apparatus body201, and a manual paper feeder113and the sheets S are fed from the cassettes111,112and the manual paper feeder113toward the image forming portion202. On the upstream side from the image forming portion202, a sheet conveying apparatus204is provided which conveys the sheet S, fed from the paper feeder203, to the image forming portion202. It is to be noted that this sheet conveying apparatus204includes conveying rollers114, pre-registration rollers115, a registration portion116, which enhances the accuracy in attitude position of the sheet S and feeds out the sheet S with good timing according to the toner image on the intermediate transfer belt, and the like.

Next, an image forming operation of the color laser printer200with such a configuration will be described. When an image forming signal is output from a control device, not illustrated, which is provided in the apparatus body201, an image signal, for example from an image reading portion, a personal computer which is not illustrated, is input into the laser scanner103. This laser scanner103then emits laser light L based on this image signal, and irradiates the photosensitive drum101with this laser light. It is to be noted that at this time, the photosensitive drum101has been previously charged by the primary charger102to have a predetermined polarity and a predetermined voltage, and the photosensitive drum101is irradiated with the laser light, to be formed with an electrostatic latent image on the surface.

This electrostatic latent images are developed by means of the toner of the respective colors, to form toner images of the respective colors on the photosensitive drums, and the toner images of the respective colors are sequentially transferred to the intermediate transfer belt106by transfer biases that are applied to the primary transfer rollers105(105ato105d). Thereby, a full-color toner image is formed on the intermediate transfer belt. It is to be noted that transfer residual toners on the photosensitive drums are collected by drum cleaners107(107ato107d).

Further, concurrently with this toner image forming operation, the sheet S accommodated in the cassette111or112or the manual paper feeder113is fed out by a pickup roller120. Thereafter, this sheet is conveyed toward the registration portion116as the skew correcting portion by the conveying rollers114and the pre-registration rollers115as the sheet conveying portion. It should be noted that a conveying speed of the sheet S at this time is a speed higher than a circumferential speed (process speed) of the image forming portion202, namely the photosensitive drum101and the intermediate transfer belt106. In the present embodiment, the process speed is set to 150 mm/s and a sheet conveying speed is set to 200 mm/s in the case of plain paper as an example.

Next, the sheet conveyed to the registration portion116in this manner is corrected in terms of skew feeding in the registration portion116, and the tip end thereof is then detected by the registration sensor117. Based on the detection of the tip end, the control device, not illustrated, computes timing for decreasing the conveying speed of the sheet S in the registration portion116to the process speed such that the tip end of the image formed on the intermediate transfer belt is aligned with the tip end of the sheet in a secondary transfer portion118.

Then, at such a speed, the toner image on the intermediate transfer belt106is transferred by secondary transfer external rollers109to the sheet S conveyed to the secondary transfer portion118, and thereafter, the transferred toner image is heated and pressurized in the fixing device110, to be fixed onto the sheet. Next, the sheet S fixed with the toner image in this manner is discharged from a discharge portion119aor119bonto a discharge tray130aor130bprovided in the apparatus body201. It should be noted that the transfer residual toner on the intermediate transfer belt106, which was not transferred in the secondary transfer portion118is collected by an intermediate transfer member cleaner108.

Incidentally, as illustrated inFIGS. 2A and 2B, the registration portion116is provided with a pair of registration rollers10,20as a pair of rotating members made up of a registration lower roller10and a registration upper roller20, and a shutter30as a shutter member (abutment member). In addition, the registration lower roller10and the registration upper roller20as the rotating members are rotatably supported by bearings, not illustrated, in the vicinities of both ends in axial directions (width directions) orthogonal to the sheet conveying direction, and are also pressurized by springs, not illustrated, to form a nip.

Further, the registration lower roller10has a plurality of rubber rollers10bfixed at predetermined intervals in the axial direction of a metal shaft10a. The registration upper roller20has a plurality of polyacetal-made rollers20bprovided so as to be opposed to the rubber rollers10bin the axial direction of the metal shaft20a. In addition, an outer diameter of the rubber roller10band an outer diameter of the roller20bare 16 mm.

On the downstream side from this pair of registration rollers10,20in the sheet conveying direction (direction of an arrow A), the shutter30is arranged along the pair of registration rollers10,20in the axial direction. The shutter30is integrally formed with a plurality of regulating pieces31in half-arc shape, and at the tip end on the lower portion of each regulating piece31, an abutment face (abutment portion)32is formed which abuts the tip end of the sheet being conveyed by the pre-registration rollers115. Specifically, each of the regulating piece31is located among the plurality of rubber rollers10bof the registration lower roller10or at each side thereof. That is, each regulating piece31is located among the plurality of nips formed by the rubber rollers10band the rollers20b, or at each end thereof in the pair of registration rollers10,20in the axial direction.

Further, the regulating piece31at each end is integrally formed with the bearing, not illustrated, and is rotatably supported in the metal shaft20aof the registration upper roller20, whereby the shutter30is rotated with the metal shaft20aof the registration upper roller20at the center when pressed by the sheet. Each of the regulating piece31is arranged in a symmetrical position with respect to the center of the pair of registration rollers10,20in the axial direction. With the plurality of regulating pieces31arranged as thus described, it is possible to handle sheets S having a variety of lengths in the width direction. InFIGS. 2A and 2B, an upper guide40and a lower guide50form a sheet conveying path R.

Incidentally, as illustrated inFIG. 3, a spring hooked portion65and a stopper portion, not illustrated, are formed on one end side of the shutter30, and a tension coil spring64as a force applying unit is hooked on the spring hooked portion65. Then, the shutter30is applied with a force by a spring force of the tension coil spring64in a counterclockwise direction (direction of an arrow B) as illustrated inFIG. 2A. In a state where the sheet is not being conveyed, the stopper portion, not illustrated, of the shutter30abuts a projecting piece, not illustrated, which is provided in the apparatus body201. Accordingly, when the sheet is not being conveyed, with the abutment face32of each regulating piece31being in a state vertical to the sheet conveying path R, the shutter30is held in the state (first attitude) of being located slightly on the upstream side from the nip of the pair of registration rollers10,20in the sheet conveying direction.

On the other hand, as described below, when skew feeding of the sheet is corrected, the tip end of the sheet comes to abut the abutment faces32of all of the regulating pieces31. In this case, a force pressed by the tip end of the sheet to the shutter30comes to overcome the applied force of the tension coil spring64, resulting in that the shutter30is rotated in a clockwise direction (direction of arrow C) with the registration upper roller20at the center as illustrated inFIG. 2B. In the course of the shutter30being pressed by the tip end of the sheet and thereby rotated, the sheet is caught by the pair of the registration rollers10,20.

Next, a skew correcting operation in the registration portion116provided with the shutter30configured as above will be described with reference toFIGS. 4A and 4Bas a view of the sheet S being conveyed by the pre-registration rollers115to the registration portion116, seen from the top side of the conveying path. Incidentally, although the driving portions of the pair of registration rollers10,20and the pre-registration roller115are not illustrated inFIGS. 4A and 4B, the pair of registration rollers10,20and the pre-registration roller115are driven by the same one driving portion. Further, the conveying speeds of these two sorts of rollers are set such that the conveying speed of the pre-registration rollers115is higher than that of the pair of registration rollers10, by the order of 1%. This is aimed at preventing the conveying speed of the pair of registration rollers10, from being lower than the conveying speed of the pre-registration rollers115due to component tolerance, and ideally, the conveying speeds of the two sorts of rollers may be the same.

Herein, as illustrated inFIG. 4A, when the sheet S is being conveyed in a direction of an arrow A in a state where its right end is ahead of its left end, with respect to the pair of registration rollers10,20, first, the right end of the sheet S abuts an abutment face32fof a regulating piece31fon the right side. At this time, since the force pressed by the sheet S to the shutter30is smaller than the applied force of the tension coil spring64which is being applied to the shutter30, the sheet S cannot rotate the shutter30against the applied force of the tension coil spring64. Therefore, in this state, the sheet S is prevented from moving in the part abutted by the regulating pieces3, and then forms a loop.

With the sheet S being skew-fed, the left end of the sheet S has not abutted an abutment face32aof a regulating piece31aon the left side. Hence the conveyance is continued by the pre-registration rollers115on one side, namely the left side, of the sheet having not abutted the regulating piece31a. Accordingly, thereafter, the left end of the sheet S having not been abutting the abutment face32aof the regulating piece31aon the left side comes into the state of abutting the abutment face32aof the regulating piece31a, as illustrated inFIG. 4B.

When both the right and left ends of the sheet S come to abut the abutment faces32a,32fof the respective regulating pieces31a,31fprovided in the vicinities of both ends of the shutter30as described above, the force pressed by the tip end of the sheet to the shutter30comes to overcome the applied force of the tension coil spring64. As a result, integrally with the regulating piece31, the shutter30is rotated by the sheet S with the registration upper roller20, which is a rotational center of the shutter30, at the center.

In this state, the sheet S is in a state where both right and left ends of the tip end thereof abut the abutment faces32of each regulating piece31, thus being located in the same position with respect to the sheet conveying direction, and skew feeding has been corrected. Although the case of the sheet S being skew-fed in the left direction as illustrated inFIG. 4Ahas been described in the present embodiment, it is obvious that, also in the case of the sheet S being skew-fed in the opposite direction (right direction), feeding correction can be performed in a similar manner.

Next, when the shutter30is rotated as thus described, the sheet S is conveyed again without an obstacle, and gets into the nip of the rubber roller10aof the registration lower roller10and the roller20aof the registration upper roller20while the skew corrected state is held. Thereafter, the sheet S is conveyed to the secondary transfer portion while the skew corrected state is held. At this time, the shutter30is rotated (moves) to the passage position (second attitude) of allowing the sheet to pass therethrough while abutting the sheet surface against the applied force, and even in a state where the regulating piece31is retracted, the regulating piece31is pressed to the sheet S with the applied force by the tension coil spring64.

Incidentally, the shutter30is provided with the plurality of regulating pieces31abutting both end portions of the sheet being conveyed in the width direction in positions corresponding to the lengths of the sheets S in the width direction, the sheet S having a variety of lengths in the width direction. Specifically, as illustrated inFIGS. 5A and 5B, when sheets with different lengths in the width direction are being conveyed, the plurality of regulating pieces (31ato31h) which are provided in the shutter30in the axial direction are arranged in positions corresponding to the outside of an image formation (margin forming portion) and slightly the inside of both ends of the sheet in the width direction. Hence the sheet S is conveyed to the secondary transfer portion while the regulating pieces31located in positions corresponding to the length of the sheet S in the width direction are pressed to the outside of the image forming region.

Herein, as described above, the sheet S performs the operation of rotating the shutter30due to the stiffness of the sheet S, and the sheet S being thick paper with a large basis weight rotates the shutter30with a relatively larger force. For this reason, when the applied force of the shutter30is excessively weak, the shutter30may be rotated just by abutment of part of the sheet S, being skew-fed, to the regulating piece31, resulting in insufficient skew correction. Accordingly, in the present embodiment, the applied force to the shutter30is set to the order of 4 to 5 N.

However, in the case of setting the applied force as thus described, when the sheet is conveyed while rotating the shutter30, the sheet top face is pressed by the regulating piece31with the order of 4 to 5 N. When the sheet top face is pressed by the regulating piece31with such a large applied force, the sheet surface may be damaged due to contact pressure by the regulating piece31.

Thereat, in the present embodiment, as illustrated inFIG. 5A, the length of the abutment face (32ato32h), constituting the abutment part that abuts the regulating piece31, on the lower side is made larger as getting closer to the outside the shutter30in the axial direction. That is, the length of the abutment face32(32ato32h) in the vertical direction is made larger as getting closer to each end from the center in the sheet width direction.

Thereby, in a state where the shutter30is rotated and the regulating piece31is retracted as illustrated inFIG. 2B, a space between the lower guide50and each of the regulating pieces31d,31elocated in the central portion of the shutter30in the axial direction is the largest, as illustrated inFIG. 5B. Further, a space between the lower guide50and each of the regulating pieces31a,31hlocated at both ends in the axial direction is the smallest. That is, the space between each of the plurality of regulating pieces31and the lower guide50is expressed as in the following equation:
Ld(≈Le)>Lc(≈Lf)>Lb(≈Lg)>La(≈Lh)

With such a configuration formed, for example at the time of conveying a sheet with the largest length in the width direction, when the shutter30is rotated, the sheet first moves while pressing all the regulating pieces31. Thereafter, however, as the sheet is conveyed, the regulating pieces31bto31gon the center side come to be separated from the image forming region in the central part of the sheet surface in the width direction due to the difference in length in the vertical direction. Thereby, only the regulating pieces31a,31h, located outside the image forming region and slightly inside both ends of the sheet in the width direction, come to press the sheet S.

Consequently, when conveyed while rotating the shutter30, the sheet S is applied with a force from the regulating piece31outside the image forming region, whereby charging that occurs due to damage or friction in the image forming region can be minimal, so as to minimize an influence on the image. It is thereby possible to reliably correct skew feeding of the sheet without causing deterioration in quality of an image on the sheet. When the sheet is conveyed in the state of being bent in the vertical direction, the regulating pieces31bto31gon the center side may abut the image forming region in the central part of the sheet surface. However, even in this case, since the regulating pieces31bto31gon the center side are configured so as to be separated from the image forming region in the central part of the sheet surface, the regulating pieces31bto31gapply a small pressing force to the sheet even when abutting the sheet, thereby not causing deterioration in image quality.

As described above, in the present embodiment, the shutter30is formed into such a shape that, when the shutter30moves by being pressed by the sheet, the contact pressure with the sheet is larger on the outer side (each end side) than at the center of the sheet in the width direction. Thereby, when pressed by the sheet, the shutter30can be moved toward the passage position while abutting a part which is outside the image forming region and in each end portion of the sheet surface. Consequently, when located in the passage position, the shutter30can be made to abut a part which is outside the image forming region and in the each end portion of the sheet surface having the image forming region in the central part in the width direction. With such a configuration formed, it is possible to allow passage of the sheet while reliably correcting skew feeding thereof without causing deterioration in image quality regardless of the type of sheet in use.

Next, a second embodiment of the present invention will be described.FIG. 6is a perspective view describing a configuration of a registration portion provided in a sheet conveying apparatus according to the present embodiment. InFIG. 6, the same numerals as inFIG. 3denote the same or corresponding parts.

InFIG. 6, a rotation shaft35is provided in an upper end portion of a shutter30A. The shutter30A is rotatably supported by the apparatus body201via this rotation shaft35. Further, this shutter30A is integrally formed with a plurality of regulating pieces31in half-arc shape in the axial direction. At the tip end of the lower portion of each regulating piece31, as illustrated inFIG. 7, an abutment face32is provided which abuts the tip end of the sheet being conveyed by the pre-registration rollers115.

Moreover, on the bottom face of the regulating piece31, a pressing portion33extending in the width direction is provided which guides the upper face of the sheet S at the time of the regulating piece31being pressed by the sheet S and rotated. In the present embodiment, this pressing portion33is provided so as to be inclined on the downstream side in the sheet conveying direction, while being integrally provided with two regulating pieces31located on each side of the shutter30A in the axial direction, as illustrated inFIG. 8. InFIGS. 7A and 7B, a stopper51abuts the pressing portion33to regulate rotation of the shutter30A, and by this stopper51, the shutter30A is held in a position of making the sheet S, being conveyed, abut the abutment faces32.

Herein, in a state where the sheet S is not being conveyed, the shutter30A is applied with a force by a spring force of the tension coil spring64in a counterclockwise direction (direction of an arrow B) as illustrated inFIG. 7A. On the other hand, when skew feeding of the sheet S is corrected, the tip end of the sheet S comes to abut the abutment faces32of all of the regulating pieces31. Thereby, the force pressed by the tip end of the sheet to the shutter30A comes to overcome the applied force of the tension coil spring64, resulting in that the shutter30A is rotated in a clockwise direction (direction of arrow C) with the rotation shaft35as a fulcrum as illustrated inFIG. 7B.

Incidentally, the guide tip end of the pressing portion33, which is provided in the shutter30A and inclined downward, extends more as getting closer to the outside in the axial direction. That is, the pressing portion33has a larger length in the vertical direction as getting closer to each end from the center in the sheet width direction. Thereby, in a state where the shutter30A is rotated and the regulating piece31is retracted as illustrated inFIG. 7B, a space between the pressing portion33and the lower guide50has a larger width as getting closer to the central portion and has a lower width as getting closer to each end of the shutter30A in the axial direction, as illustrated inFIG. 9B. Similarly, a space between the pressing portion33and the sheet S also has a larger width as getting closer to the central portion and has a lower width as getting closer to each end of the shutter30A in the axial direction, as illustrated inFIG. 9B(Lout>Lin).

Herein, as described above, the operation of the sheet S to rotate the shutter30A is performed due to the stiffness of the sheet S, but even in the state where the shutter30A is rotated and the regulating piece31is retracted, the pressing portion33is pressed to the sheet S with the applied force by the spring. However, since the length of the downwardly inclined pressing portion33in the vertical direction is made larger as getting closer to the outside in the axial direction, when the shutter30A is rotated, the regulating piece31comes into the state of being most strongly pressed at each end of the sheet S in the width direction. Further, the force with which the pressing portion33is pressed to the sheet S is smaller in a position closer to the central portion of the sheet S.

Consequently, when conveyed while rotating the shutter30A, the sheet S is applied with a force from the regulating piece31outside the image forming region, whereby charging that occurs due to damage or friction in the image forming region can be minimal, so as to minimize an influence on the image.

As described above, as in the present embodiment, since the length of the pressing portion33in the vertical direction is made larger as getting closer to the outside of the axial direction, it is possible to reliably correct skew feeding of the sheet without causing deterioration in quality of an image on the sheet. Further, since the length of the pressing portion33in the vertical direction is made larger as getting closer to the outside in the axial direction, it is possible to reliably correct skew feeding of the sheet of any size without causing deterioration in quality of an image on the sheet.

It should be noted that, although specific values of the process speeds, the applied force to the shutter and the like for plain paper and thick paper have been mentioned in the above description, the present invention is not restricted to these numeral values. Further, although the registration portion located immediately before the image forming portion has been described above, it may be located in any place so long as serving to correct skew feeding of a sheet.

Further, although the present invention has been described above by taking the image forming apparatus of the electrophotographic system as the example, it can also be applied to an image forming apparatus which performs a similar skew correcting operation, such as an image forming apparatus of an inkjet system. Moreover, although the skew correcting portion has been described in the present embodiment, the present invention can also be applied to the conveying path switching member arranged inside the sheet conveying path, and also in this case, damage, friction and the like of the sheet surface can be prevented so as to obtain a similar effect.

This application claims the benefit of Japanese Patent Application No. 2010-165158, filed Jul. 22, 2010, which is hereby incorporated by reference herein in its entirety.