JP7225365B2 - Sheet feeding device and image forming device - Google Patents

Description

The present invention relates to a sheet feeding device for feeding sheets and an image forming apparatus having the same.

In general, an image forming apparatus such as a printer is configured to be able to feed sheets of a plurality of sizes. Standard size sheets such as A4 and B5 are stored in cassettes, and long sheets that are long in the conveying direction (hereinafter referred to as , long sheets) are configured to be placed on the manual feed tray.

Conventionally, a manual feed tray is composed of a first holding portion that holds the front portion of the long sheet and a second holding portion that holds the rear portion of the long sheet. An image forming apparatus has been proposed which is integrally provided with a guide portion for determining the posture of the image forming apparatus (see Patent Document 1). The long sheet is accommodated in an upwardly curled posture by the first holding section, the second holding section and the guide section. A force that pushes the long sheet into the feeding roller pair (hereinafter referred to as pushing force) acts. If the pressing force is strong, the leading edge of the long sheet may go over the nip of the pair of feeding rollers, which may cause feeding failure. For this reason, an image forming apparatus has been proposed in which a concave portion is provided in a first holding member that holds the front portion of the long sheet, and the long sheet is bent downward in the concave portion to reduce the pressing force (Patent Document 2). reference).

JP 2007-031093 A JP 2010-013276 A

However, the image forming apparatus described in Japanese Patent Application Laid-Open No. 2002-200020 has a problem that the size of the apparatus is increased because it is necessary to secure a large concave portion so that the long sheet can be sufficiently curved. In addition, particularly in the case of a long sheet with high rigidity, there is a possibility that the pressing force is not sufficiently relieved because the concave portion hardly bends, resulting in feeding failure.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sheet feeding device and an image forming apparatus having the same, in which the pressing force of the sheet is sufficiently relaxed to solve the above-described problems.

In the sheet feeding device of the present invention, a sheet support portion has a support surface that supports a sheet from below in the vertical direction , and a guide surface that guides the sheet supported by the support surface so that the sheet is curved upward. an abutment portion against which the leading edge of the sheet supported by the support surface abuts; and a feeding rotary member for feeding the sheet supported by the support surface and abutted against the abutment portion in the sheet feeding direction. a first friction member provided on the support surface so as to face the feeding rotary member and having a first friction surface having a static friction coefficient larger than that of the support surface; a second friction member arranged upstream of the friction member, provided on the support surface , and having a second friction surface having a larger coefficient of static friction than the support surface ; upstream of the first friction member in the sheet feeding direction and separated from the lower end of the guide surface by a distance equal to or greater than 1/4 of the distance from the abutment portion to the lower end of the guide surface in the horizontal direction It is characterized by being arranged at a position .

According to the present invention, the pressing force of the sheet can be reduced by the second friction member , and feeding failure can be prevented.

1 is an overall schematic diagram showing a printer according to a first embodiment; FIG. FIG. 4 is a side view showing the manual feeding device in which the pickup roller is positioned at the separated position; FIG. 4 is a side view showing the manual feeding device with the pickup roller positioned at the feeding position; Explanatory drawing which shows the force which acts on a long sheet. FIG. 2 is a schematic diagram showing Reference Example 1 according to the present embodiment; FIG. 4 is a schematic diagram showing Reference Example 2 according to the present embodiment; FIG. 10 is a side view showing a manual feeding device according to a second embodiment; FIG. 11 is a side view showing a manual feeding device according to a third embodiment; The side view which shows the modification of 3rd Embodiment.

<First embodiment>
〔overall structure〕
First, a first embodiment of the present invention will be described. A printer 1 as an image forming apparatus according to the first embodiment is an electrophotographic laser beam printer. As shown in FIG. 1, the printer 1 includes an image forming unit 60 that forms an image on a sheet S, a cassette feeding device 50, a manual feeding device 100, a fixing device 15, and a discharge roller pair 16. have. The image forming unit 60 includes four process cartridges 4Y, 4M, 4C, and 4K for forming four-color toner images of yellow (Y), magenta (M), cyan (C), and black (K), and a scanner unit. 9 and . These four process cartridges 4Y, 4M, 4C, and 4K are arranged in a line substantially horizontally.

The four process cartridges 4Y, 4M, 4C, and 4K have the same configuration except that the colors of the images formed are different. Therefore, only the configuration of the process cartridge 4Y and the image forming process will be described, and the description of the process cartridges 4M, 4C, and 4K will be omitted.

The process cartridge 4Y has a photosensitive drum 5Y, a charging roller 6Y, and a developing roller 7Y. The photosensitive drum 5Y is formed by applying an organic photoconductive layer to the outer periphery of an aluminum cylinder, and is rotated by a driving motor (not shown). An intermediate transfer belt 11 is arranged above the process cartridges 4Y, 4M, 4C, and 4K. The intermediate transfer belt 11 is stretched around a drive roller 12 , a secondary transfer counter roller 14 a and a tension roller 13 , and a cleaning device 18 is provided facing the tension roller 13 .

Inside the intermediate transfer belt 11, primary transfer rollers 17Y, 17M, 17C, and 17K are provided. A secondary transfer roller 14b is provided on the opposite side of the secondary transfer opposing roller 14a with the intermediate transfer belt 11 interposed therebetween. The fixing device 15 has a fixing roller 15a that is heated by a heater, and a pressure roller 15b that presses against the fixing roller 15a. The cassette feeding device 50 is provided below the printer 1 and has a cassette 30 that accommodates the sheets S therein. Sheets S housed in the cassette 30 are fed by a pickup roller 31 and separated one by one by a separation roller pair 32 . The main body 1A of the printer 1 supports a right door 40 so that it can be opened and closed. By opening the right door 40, a part of the sheet conveying path along which sheets are conveyed can be opened to perform jam processing. .

Next, the image forming operation of the printer 1 configured as described above will be described. When an image signal is input to the scanner unit 9 from a personal computer (not shown) or the like, the scanner unit 9 irradiates a laser beam corresponding to the image signal onto the photosensitive drum 5Y of the process cartridge 4Y.

At this time, the surface of the photosensitive drum 5Y is uniformly charged to a predetermined polarity and potential by the charging roller 6Y, and an electrostatic latent image is formed on the surface by being irradiated with laser light from the scanner unit 9. . The electrostatic latent image formed on the photosensitive drum 5Y is developed by the developing roller 7Y to form a yellow (Y) toner image on the photosensitive drum 5Y.

Similarly, the photosensitive drums of the process cartridges 4M, 4C, and 4K are also irradiated with laser light from the scanner unit 9, and magenta (M), cyan (C), and black (K) toner images are formed on the respective photosensitive drums. be done. The toner images of respective colors formed on the respective photosensitive drums are transferred onto the intermediate transfer belt 11 by the primary transfer rollers 17Y, 17M, 17C, and 17K, and transferred to the secondary transfer roller 14b by the intermediate transfer belt 11 rotated by the drive roller 12. transported to. Note that the image forming process of each color is performed at the timing of superimposing on the upstream toner image that has been primarily transferred onto the intermediate transfer belt 11 .

In parallel with this image forming process, skew feeding of the sheet S sent out by the cassette feeding device 50 or the manual feeding device 100 is corrected by the registration roller pair 8 . Further, the registration roller pair 8 conveys the sheet S toward the secondary transfer roller 14 b in accordance with the toner image conveyed by the intermediate transfer belt 11 . The full-color toner image on the intermediate transfer belt 11 is transferred to the sheet S at the nip formed by the secondary transfer counter roller 14a and the secondary transfer roller 14b by the secondary transfer bias applied to the secondary transfer roller 14b. be done. Further, toner remaining on the surface of the intermediate transfer belt 11 is removed by the cleaning device 18 after the toner image is transferred.

A fixing roller 15a and a pressure roller 15b of the fixing device 15 apply predetermined heat and pressure to the sheet S onto which the toner image has been transferred, so that the toner is melted and fixed (fixed). After passing through the fixing device 15 , the sheet S is discharged to the discharge tray 19 by the discharge roller pair 16 .

[Manual feeder]
Next, the manual feeding device 100 will be described with reference to FIGS. 2 and 3. FIG. The manual feeding device 100 has a tray unit 112, a rear end tray 103, a pickup roller 121, a feed roller 122, and a separation roller 123, as shown in FIG. The feed roller 122 is rotatably supported by a rotary shaft 125 supported by a feed frame (not shown), and the feed arm 105 is rotatably supported by the rotary shaft 125 . The feeding arm 105 can be moved up and down by a lifting means (not shown), and a pick-up roller 121 is rotatably supported at the tip of the feeding arm 105 around a rotation shaft 124 .

A pick-up roller 121 as a feeding rotating member is movable between a separation position (position shown in FIG. 2) and a feeding position (position shown in FIG. 3) by raising and lowering the feeding arm 105. . The pickup roller 121 is separated from the sheet placed on the tray unit 112 at the separation position, and contacts the sheet placed on the tray unit 112 at the feeding position. A pressure spring 106 is stretched between the feeding arm 105 and a feeding frame (not shown), and the pressure spring 106 applies a predetermined feeding pressure to the pickup roller 121 positioned at the feeding position. Granted. It should be noted that the pickup roller 121 is not limited to a roller, and may be configured by another rotating body such as a belt.

A driving force is input to a rotating shaft 125 of the feed roller 122 from a motor M, and the driving force of the motor M input to the rotating shaft 125 is picked up by a gear train (not shown) supported by the feeding arm 105. It is transmitted to the roller 121 . The separation roller 123 is rotatably supported by a rotary shaft 126 via a torque limiter (not shown), and the rotary shaft 126 is supported by a separation roller holder 107 that can swing around a swing shaft 107a. . The separation roller holder 107 is biased by a pressure spring 108 , and the separation roller 123 is in contact with the feed roller 122 with a predetermined pressure due to the biasing force of the pressure spring 108 .

When an image forming job having the manual feeder 100 as a feeding source is input, the pickup roller 121 is lowered from the separated position to the feeding position to pick up the sheet placed on the tray unit 112 as shown in FIG. abut. By driving the motor M in this state, the sheet placed on the tray unit 112 is fed by the pickup roller 121 toward the separation nip 130 formed by the feed roller 122 and the separation roller 123 .

When only one sheet is fed to the separation nip 130 by the pickup roller 121 , the torque limiter provided between the rotating shaft 126 and the separation roller 123 idles, and the separation roller 123 is pulled along with the feed roller 122 . spin. Further, when two or more sheets are fed by the pickup roller 121, the separation roller 123 stops rotating to prevent the second and subsequent sheets from being conveyed. The separation roller 123 may be driven in the direction opposite to the sheet feeding direction, and a separation pad may be provided instead of the separation roller 123 .

[Main tray and trailing tray]
Next, the tray unit 112 and trailing end tray 103 will be described in detail. Also, a case where a long sheet (hereinafter referred to as a long sheet) LS is placed on the tray unit 112 and the rear end tray 103 will be described below. The tray unit 112 as a tray unit sheet support section is composed of a manual feed tray 101 and an intermediate guide 102 as shown in FIG. The intermediate guide 102 is fixed to the front end of the manual feed tray 101 and is inclined upward in the sheet feeding direction. The intermediate guide 102 has a guide surface 102 a that guides the long sheet LS to curve upward between the manual feed tray 101 and the trailing end tray 103 .

A manual feed tray 101 as a tray is rotatably supported by the right door 40, and a rear end tray 103 as a rear end support is attached to the right door 40 so as to overlap the manual feed tray 101 when viewed from the vertical direction. It is fixed detachably. The manual feed tray 101, the intermediate guide 102, and the rear end tray 103 are made of resin or sheet metal. The manual feed tray 101 has a first surface 101L arranged below the pickup roller 121, a second surface 101R arranged upstream of the first surface 101L in the sheet feeding direction, and a second surface 101R arranged downstream of the first surface 101L. and a third surface 101c. The first surface 101L inclines downward as it approaches the separation nip 130, and the second surface 101R inclines downward as it approaches the separation nip 130 at a smaller inclination angle than the first surface 101L. Also, the third surface 101c is inclined upward as it approaches the separation nip 130 .

That is, the third surface 101c and the first surface 101L have a concave shape that slopes downward toward the valley portion 101d, and the first surface 101L and the second surface 101R have a convex shape that faces the peak portion 101b. there is The third surface 101c, the first surface 101L, the second surface 101R, and the guide surface 102a of the intermediate guide 102 constitute a support surface 113 that supports the sheet. A first friction member 129 is provided on the first surface 101L of the manual feed tray 101 so as to face the pickup roller 121, and the first friction member 129 has a higher coefficient of static friction than the support surface 113 of the tray unit 112. It has a first friction surface 129a. The first friction surface 129a is configured to contact the pickup roller 121 via the long sheet LS placed on the tray unit 112, and the lowest sheet placed on the tray unit 112 is the upper sheet. to prevent them from being taken to Note that the first friction member 129 and the second friction member 150, which will be described later, are illustrated in the drawings (for example, FIGS. 2 to 4) so as to be thicker than they actually are for the sake of explanation. It is formed so thin that it does not affect the Also, the first friction member 129 may be omitted.

When the long sheet LS is placed on the support surface 113 of the tray unit 112, the long sheet LS is guided such that its leading end is supported by the manual feed tray 101 and its intermediate portion is curved upward by the intermediate guide 102. be done. The trailing end portion of the long sheet LS guided by the intermediate guide 102 is supported by the trailing end tray 103 . Part of the weight of the long sheet LS on the trailing end side is held by the trailing end tray 103 and the rest is held by the tray unit 112 . When the leading edge of the long sheet LS abuts against the separation nip 130 , the weight and reaction force of the long sheet LS cause the leading edge of the long sheet LS to move toward the separation nip 130 . A pushing force (hereinafter referred to as a pushing force) acts. If this pushing force is greater than the frictional resistance of the separation nip 130, the leading edge of the long sheet LS may exceed the separation nip 130, resulting in feeding failure.

Therefore, in the present embodiment, the second friction member 150 is provided on the second surface 101R of the manual feed tray 101, and the second friction member 150 can contact the long sheet LS placed on the tray unit 112. has a second friction surface 150a. FIG. 4 shows the distribution of forces acting on the long sheet LS. As shown in FIG. 4, when the rear end of the long sheet LS abuts against the right door 40, a force F1 acts on the rear end of the long sheet LS. A force F3 based on the weight of the long sheet LS acts on the long sheet LS toward the manual feed tray 101, and reaction forces F2 and F2 due to the bending of the long sheet LS by the intermediate guide 102 also act. do. Under these influences, a pushing force F acts on the leading edge of the long sheet LS toward the separation nip 130 .

On the other hand, a normal force N is generated between the second friction member 150 and the long sheet LS due to the force F3, and a frictional force μN in the direction opposite to the pushing force F acts on the long sheet LS. do. The static friction coefficient μ of the second friction member 150 is set to be higher than the static friction coefficient of the support surface 113 of the tray unit 112. For example, the second friction member 150 is made of rubber material or suede material. It is formed in a sheet shape from the base and along the support surface 113 . Such a frictional force μN reduces the pressing force F acting on the long sheet LS. In addition, the concave shape formed by the third surface 101c and the first surface 101L bends the long sheet LS downward, thereby reducing the pushing force F acting on the leading edge of the long sheet LS. Therefore, it is possible to prevent the leading end of the long sheet LS from going over the separation nip 130, thereby reducing feeding failures.

[Arrangement of Second Friction Member]
Next, an effective arrangement of the second friction member 150 will be described. In order to increase the frictional resistance of the second friction member 150 and further reduce the pressing force F, the normal force N should be large. Therefore, it is preferable to arrange the second friction member 150 at a position where the normal force N is maximized.

Here, reference examples 1 and 2 according to the present embodiment will be described with reference to FIGS. 5 and 6. FIG. 5 shows Reference Example 1 in which the manual feed tray 201 is provided along the horizontal direction, and FIG. 6 shows Reference Example 2 in which the manual feed tray 202 is provided at an angle of 20 degrees with respect to the horizontal direction. ing.

In Reference Examples 1 and 2, an abutment member 160 is provided upstream of the separation nip 130 in the sheet feeding direction. move together. That is, when the feeding arm 105 is at the raised position, the abutting member 160 abuts against the sheet to restrict movement in the sheet feeding direction, and when the feeding arm 105 is at the lowered position, the abutment member 160 abuts the sheet. The movement of the sheet is not regulated by retreating from the conveying path.

As shown in FIG. 5, when the long sheet LS placed on the manual feed tray 201 is being guided by the intermediate guide 102 so as to be curved upward, the vicinity of the connecting portion between the manual feed tray 201 and the intermediate guide 102 , the long sheet LS floats in the air. Accordingly, there is a non-contact section A where the long sheet LS does not contact the manual feed tray 201 and the intermediate guide 102 . In the following table, in each of Reference Examples 1 and 2, when the long sheet LS having a basis weight of 128 gsm and a length of 900 mm is stacked on the manual feed tray, the non-contact section A and the curvature of the curved portion of the long sheet LS An example of the relationship with R is shown. Note that "front end to intermediate guide" indicates the horizontal distance from the abutment member 160 to the intermediate guide 102, and the non-contact section A is also represented by the horizontal distance.

As shown in Table 1, the distance of the non-contact section A also differs depending on the inclination angle of the manual feed tray. Considering the width required for the printer 1 of the present embodiment, the type of sheet used, etc., the non-contact section A is 1/4 of the horizontal distance from the abutting member 160 to the intermediate guide 102. distance less than

When the second friction member 150 (see FIG. 4) is provided in the non-contact section A, no force acts on the second friction member 150 from the long sheet LS, and no normal force N is generated. Therefore, the second friction member 150 is provided downstream of the non-contact section A in the sheet feeding direction. That is, the second friction member 150 is desirably provided on the support surface 113 at a position apart from the intermediate guide 102 by a distance of 1/4 or more of the distance from the abutment member 160 to the intermediate guide 102 in the horizontal direction. . This relationship is also established in FIG. 4, and the separation nip 130 constitutes an abutting portion against which the leading edge of the sheet abuts.

Further, as shown in FIG. 3, downstream of the pickup roller 121 in the sheet feeding direction, the position of the long sheet LS is determined by the abutting portion between the pickup roller 121 and the manual feed tray 101 and the separation nip 130 . be. Therefore, especially when the manual feed tray 101 has a concave shape downstream of the pickup roller 121 in the sheet feeding direction as in the present embodiment, even if the second friction member 150 is provided downstream of the pickup roller 121, the vertical Almost no drag force N is generated. Therefore, it is desirable that the second friction member 150 be provided upstream of the pickup roller 121 in the sheet feeding direction.

In addition, when manual feed tray 101 has a convex shape facing ridge 101b as in the present embodiment, the long sheet LS tends to apply force to the vicinity of ridge 101b. In particular, the second surface 101R extending in the direction crossing the sheet feeding direction 170 (the direction indicated by the two-dot chain line in FIG. 3) formed by the contact between the pickup roller 121 and the first surface 101L of the manual feed tray 101 A force tends to act near the peak 101b. Therefore, the second friction member 150 is arranged on the side of the second surface 101R closer to the first surface 101L.

Further, as shown in FIG. 4, the second friction member 150 is provided at a position closer to the pickup roller 121 (see FIG. 2) than the straight line 114 through which the leading end 103a of the trailing end tray 103 passes. That is, at least a portion of the second friction member 150 is provided at a position closer to the pickup roller 121 than the leading end 103a of the trailing end tray 103 in the horizontal direction.

As described above, by arranging the second friction member 150 at an appropriate position in the tray unit 112, the pushing force F can be reduced by the friction force μN of the second friction member 150. Therefore, it is possible to reduce feeding failures. In addition, since the pressing force F is relaxed, it is possible to reduce damage such as folding of the leading edge of the sheet.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. In the second embodiment, the second friction member 150 of the first embodiment is configured in a different shape. Therefore, the configuration similar to that of the first embodiment will be omitted from illustration or given the same reference numerals in the drawings.

As shown in FIG. 7, the second friction member 250 of the manual feeder 200 is provided on the second surface 101R of the manual feed tray 101, and its arrangement is as described in the first embodiment. is. The second friction member 250 protrudes from the second surface 101R forming part of the support surface 113 of the tray unit 112, and has a first inclined surface 250a and a second inclined surface 250b. The first inclined surface 250a is inclined away from the second surface 101R toward the downstream side in the sheet feeding direction, and the second inclined surface 250b is inclined toward the second surface toward the downstream side in the sheet feeding direction. It is inclined to approach 101R. That is, the first inclined surface 250a and the second inclined surface 250b protrude from the second surface 101R of the manual feed tray 101 in a mountain shape.

A first inclined surface 250a as a second friction surface of the second friction member 250 extends so as to intersect with the sheet feeding direction 170 (the direction indicated by the two-dot chain line in FIG. 7), and the weight of the long sheet LS is reduced. It is now possible to receive As a result, the pressing force F (see FIG. 4) of the long sheet LS can be reduced, and feeding failures can be reduced.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. The third embodiment is configured by changing the arrangement of the second friction member 150 of the first embodiment. Therefore, the configuration similar to that of the first embodiment will be omitted from illustration or given the same reference numerals in the drawings.

As shown in FIG. 8 , the sheet-like second friction member 350 of the manual feeding device 300 is provided on the guide surface 102 a of the intermediate guide 102 . The long sheet LS is curved by the intermediate guide 102 to generate reaction forces F2 and F2, and presses the intermediate guide 102 with a pressing force F5. Therefore, the second friction member 350 provided on the intermediate guide 102 applies frictional resistance to the long sheet LS based on the pressing force F5. With this frictional resistance, the pressing force F of the long sheet LS can be reduced, and feeding failures can be reduced.

As shown in FIG. 9, a mountain-shaped second friction member 450 similar to that described in the second embodiment may be provided on the intermediate guide 102 . The second friction member 450 as a resistance part has a first inclined surface 450a and a second inclined surface 450b as in the second embodiment. It is tilted by θ2. A guide surface 102a of the intermediate guide 102 is inclined with respect to the horizontal direction by an angle θ1 larger than the angle θ2. Therefore, part of the force F3 based on the weight of the long sheet LS can be received by the first inclined surface 450a, and combined with the frictional resistance based on the pressing force F5, the pushing force of the long sheet LS can be reduced. . As a result, feeding failures of the long sheet LS can be reduced. It is of course desirable to provide the second friction member 450 at a location that contacts the long sheet LS, taking into consideration the characteristics of the long sheet LS and the shape of the intermediate guide 102 . In addition, the second friction member 450 does not have to have a second friction surface having a higher coefficient of static friction than the support surface 113 on the first inclined surface 450a. You may Also, the second friction member 450 may be configured integrally with the intermediate guide 102 .

In any of the above-described forms, the second friction members 150, 250, 350, 450 may be provided detachably with respect to the tray unit 112. For example, the second friction members 150, 250, 350, 450 are detachable by means of seals, snap-fits, screws, or the like. Alternatively, the tray unit 112 may be provided with a plurality of mounting holes, and the second friction members may be selectively mounted in the plurality of mounting holes so that the mounting positions of the second friction members can be moved. Further, the material and shape of the second friction surface where the second friction member contacts the long sheet may be varied according to the size and basis weight of the long sheet LS, or a plurality of second friction members may be provided. good.

Further, the second friction members 150, 250, 350, and 450 do not need to have a static friction coefficient higher than that of the tray unit 112. At least the second friction surface has a static friction coefficient of It should be higher than the support surface 113 of the tray unit 112 . Further, the material of the second friction surface is not limited to a rubber material or suede material as long as the coefficient of static friction is higher than that of the support surface 113 .

Moreover, the shape of the manual feed tray 101 is not limited, and it does not necessarily have the first surface 101L, the second surface 101R, and the third surface 101c as in the above-described embodiment.

Further, in any of the above embodiments, the sheet is fed by the pickup roller 121, but the present invention is not limited to this. That is, instead of providing the pickup roller 121, the manual feed tray 101 may be provided with a vertically movable intermediate plate. You can send

In addition, although the electrophotographic printer 1 has been used in each of the above-described embodiments, the present invention is not limited to this. For example, the present invention can also be applied to an inkjet image forming apparatus that forms an image on a sheet by ejecting ink liquid from nozzles.

1: Image forming apparatus (printer) / 60: Image forming unit / 100, 200, 300: Sheet feeding device (manual feeding device) / 101: Tray (manual feeding tray) / 101L: First surface / 101R: Second surface Surface/102: Intermediate guide/102a: Guide surface/103: Rear end support portion, rear end tray/112: Sheet support portion (tray unit)/113: Support surface/121: Feed rotating body (pickup roller)/129 : First friction member/129a: First friction surface/130: Abutting portion (separation nip)/150, 250, 350, 450: Second friction member/150a, 250a, 350a, 450a: Second friction surface/170 : sheet feeding direction/250a, 450a: first inclined surface/250b, 450b: second inclined surface

Claims (10)

a sheet support portion having a support surface that supports the sheet from below in a vertical direction and a guide surface that guides the sheet supported by the support surface so that the sheet curves upward;
an abutting portion with which the leading edge of the sheet supported by the support surface abuts;
a feeding rotator that feeds in a sheet feeding direction the sheet that is supported by the supporting surface and abutted against the abutting portion;
a first friction member provided on the support surface so as to face the feeding rotating body and having a first friction surface having a static friction coefficient larger than that of the support surface;
a second friction member disposed upstream of the first friction member in the sheet feeding direction, provided on the support surface, and having a second friction surface having a larger static friction coefficient than the support surface;
The second friction member is located upstream of the first friction member in the sheet feeding direction, and is located at a distance equal to or greater than 1/4 of the distance from the abutment portion to the lower end of the guide surface in the horizontal direction. positioned at a distance from the lower end of the guide surface;
A sheet feeding device characterized by: The second friction member is configured in a sheet shape along the support surface,
2. The sheet feeding apparatus according to claim 1, wherein: The second friction member includes a first inclined surface that protrudes from the support surface and is inclined away from the support surface toward the downstream side in the sheet feeding direction to constitute the second friction surface; a second inclined surface that inclines so as to approach the support surface as it goes downstream in the feeding direction;
2. The sheet feeding apparatus according to claim 1, wherein: a rear end tray arranged above the support surface in the vertical direction and supporting a rear end portion of the sheet that is supported by the support surface and curved upward by the guide surface;
At least part of the second friction member is provided at a position closer to the feeding rotor than the tip of the rear end tray in the horizontal direction.
4. The sheet feeding device according to claim 1, wherein: The support surface includes a first surface arranged below the feeding rotary member and inclined downward as it approaches the abutting portion, and an upstream surface arranged upstream of the first surface in the sheet feeding direction. a second surface that slopes downward as it approaches the abutting portion at an angle of inclination smaller than that of the first surface;
The second friction member is arranged on a side of the second surface closer to the first surface,
5. The sheet feeding apparatus according to claim 1, wherein: The second friction member is detachably attached to the support surface,
6. The sheet feeding device according to any one of claims 1 to 5, characterized in that: wherein the second friction member is made of a rubber material or a suede material;
The sheet feeding device according to any one of claims 1 to 6, characterized in that: the sheet support section includes a manual feed tray having the support surface and an intermediate guide having the guide surface;
The intermediate guide is fixed to the manual feed tray,
The sheet feeding device according to any one of claims 1 to 7, characterized in that: The guide surface is positioned upstream of the support surface in the sheet feeding direction and is inclined upward toward the upstream side in the sheet feeding direction.
The sheet feeding device according to any one of claims 1 to 8, characterized in that: The sheet feeding device according to any one of claims 1 to 9;
an image forming unit that forms an image on a sheet fed from the sheet feeding device;
An image forming apparatus characterized by:

Images