JPH10291661A - Sheet feeder, image reader, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent image on back side of most upper sheet from soiling the surface of its just under sheet during sheet feeding, by changing contact between a sheet feeder and a most upper sheet both for relative position in relation to the most upper sheet and for absolute position. SOLUTION: The sheet feeder 1 has an elastic non-end belt 8 which is tightly wound around belt shafts 10, 11, a rotational member 2 as a contact moving means which is inscribed with the non-end belt 8, energizes the non-end belt 8 so as to contact it with a sheet, and moves along the sheet, and a pick roller 12 as a rotating roller at a part which is inscribed with the belt 8 of the rotational member 2. When feeding operation is performed in this structure, contact between the belt 8 and a most upper sheet changes both for its relative position and for absolute position. Therefore, the most upper sheet dose not move due to its sliding friction, and soil due to image on back side of most upper sheet is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electronic copying machine, a printer, a facsimile, etc., and a sheet feeding apparatus provided in an image reading apparatus for feeding sheets such as originals and recording materials. Things.

[0002]

2. Description of the Related Art A conventional sheet feeding device for feeding a sheet to an image forming apparatus such as an electronic copying machine is a sheet feeding device of a retard roller type including a pickup roller, a conveying roller, a separation roller (reverse roller) and the like. There is a sending device. This retard roller type sheet feeding apparatus is generally used because it can stably separate and feed a sheet such as recycled paper which is likely to be double fed.

FIG. 6 shows a conventional example of a retard roller system.

In the retard roller type sheet feeding apparatus, a pickup roller 101 supported by a swingable arm 102 and movable to a sheet feeding position (A) and a standby position (B) is moved at a sheet feeding position A. By rotating, the uppermost sheet is sent out.

The sheet sent out by the pickup roller 101 enters a nip portion between the conveying roller 114 and the separation roller 115, where the sheet is separated one by one.

The transport roller 114 receives a driving force from a driving source so as to rotate in the direction in which the sheet advances, and rotates.
The separation roller 115 receives a driving force from a driving source via a torque limiter (not shown) so as to rotate in a direction for preventing the sheet from advancing.

When one sheet enters the nip between the transport roller 114 and the separation roller 115, the driving force to the separation roller 115 is cut off by the torque limiter.
The separation roller 115 rotates together with the transport roller 114.

When two or more sheets enter, the separation roller 115 rotates in a direction to prevent the sheet from advancing, thereby preventing the sheet from being conveyed on the separation roller 115 side.
Only the sheet on the conveying roller 114 side is sent out. When the sheet is fed by the transport roller 114, the pickup roller 101 moves to the standby position B in preparation for feeding the next sheet.

Next, the movement of the pickup roller 101 will be described.

FIG. 7 shows a schematic configuration of a sheet feeding apparatus.

The pickup roller 101 has an arm 102
The arm 102 is rotatably mounted on the shaft 1.
03 is swingably attached. Further, the pickup roller 101 is rotatable by driving force of a driving motor 106 via driving belts 104 and 105. Further, the swing support lever 107 is swingable about a shaft 108. The swing support lever 107 swings, and the arm 102 can be swung upward by pushing up the portion C. The swing support lever 107 is swingable by a stepping motor 110 via a drive belt 109.

With the above configuration, the pickup roller 10
1 is the standby position (stepping motor 110
The rocking support lever 107 pushes the arm 102 upward by the driving of the arm, and is separated from the sheet 111).
Feed position (by driving the stepping motor 110,
The swing support lever 107 is lowered, and the pickup roller 1
01 is in contact with the sheet 111).

The pickup roller 101 is rotated by the drive of the drive motor 106 at the feeding position, and feeds the sheet 111 from above. The sheet sent out by the pickup roller 101 enters a nip portion between a conveyance roller and a separation roller (not shown), where it is separated one by one and further conveyed downstream.

[0014]

The configuration described above has the following disadvantages.

FIG. 8 shows that, when the retard roller type sheet feeding apparatus is applied to feeding of an original, the pickup roller 101 is used to feed the original 1 as a sheet.
FIG. 11 is an enlarged view of the vicinity of a pickup roller in a state where the sheet feeding roller 11 is being fed.

The pickup roller 101 is pressed against the document 111 with a force indicated by _P in the figure, and rotates in the arrow Q direction at a peripheral speed corresponding to the sheet feeding speed VP. .

[0017] the back side of the document P ₁ stacked on top of the original 111, a case where image T formed by such toner is present.

The original P ₁ is the rotation of the pickup roller, but Yuku is fed into the apparatus main assembly interior at a velocity V _P, the document P ₂ of the immediately below, by the separation means mentioned above, the original P ₁ The sheets are not fed together, and the stacked state is maintained.

[0019] That is, the image T on the back of the document P ₁ is always on the region S indicated by oblique lines of the next document P _2, the pressure P
And is moved by being rubbed and rubbed, and this appears as dirt on the shaded area S.

When an original that has been soiled once is used again, the stain is read as a part of the image information, causing a problem that the image is deteriorated.

Also, let P be the roller pressure, μp be the friction coefficient between the document and the document, and μr be the friction coefficient between the roller and the document, and consider a realistic and unexpected external force F (such as electrostatic attraction force between the documents). In this case, the relationship of P * μr> P * μp + F is required for the feeding.

In other words, considering the factors of external force, the minimum pressure P is required for document feeding, and this is a relationship that needs to be established per unit area. Therefore, regardless of the roller contact area, Unless the pressure is above a certain level, slip will occur.

[0023] In Thus, an attempt to improve the level of dirt on the document P _2, by setting the pressure P that presses the document P ₁ on the document P ₂ small, slip between the pickup roller 101 and the document P ₁ This causes so-called paper feeding failure such as a delay in paper feeding timing.

The same problem occurs not only when a document is fed, but also when a recording material having an image formed on the back side is fed.

The present invention has been made in order to solve the above-mentioned problems of the prior art. It is an object of the present invention that an image on the back of the uppermost sheet is displayed on the sheet immediately below it during sheet feeding. An object of the present invention is to provide a high-quality sheet feeding apparatus capable of maintaining the quality of sheets during feeding without soiling the surface.

[0026]

In order to achieve the above object, according to the present invention, a conveying force is applied to the uppermost one of the sheets placed on a sheet placing table while abutting the sheet. In the sheet feeding device using the sheet feeding means, the contact point between the sheet feeding means and the uppermost sheet is displaced both in the relative position with respect to the uppermost sheet and in the absolute position. Features.

The sheet feeding means includes an elastic endless belt stretched and suspended, an endless belt inscribed in the endless belt, and a biasing force applied to the endless belt to contact the sheet. Contact moving means moving along the endless belt, the relative position of the contact between the endless belt and the sheet relative to the sheet is displaced by the rotation of the endless belt itself, and the absolute position is displaced by the contact moving means. It is characterized by.

The contact moving means is a rotating member that rotates about an axis provided inside the endless belt, and a rotating roller is provided at a portion of the rotating member that is in contact with the belt. The moving direction of the contact by the contact moving means is opposite to the sheet feeding direction.

The sheet feeding means includes a rotating means which comes into contact with the sheet, and the conveying force is a combined force of a friction force caused by rotation of the rotating means itself and a friction force caused by movement of the rotating means itself.

The sheet feeding means includes a rotating means, a first swinging means for swinging the rotating shaft of the rotating means substantially parallel to the sheet, and a swinging axis of the first swinging means substantially perpendicular to the sheet. And a second rocking means for rocking the sheet at the time of sheet feeding.
First and second swinging means operate to move the absolute position of the contact point between the rotating means and the sheet in parallel with the sheet, and after the sheet is fed, the rotating means is separated from the sheet by the second swinging means. And returning to a position before feeding by the first swinging means.

The absolute position of the contact point between the rotating means and the sheet is moved in a direction opposite to the sheet feeding direction.

The sheet feeding means contacts the sheet,
Rotating means for applying frictional force in two independent directions on the sheet surface, wherein the rotating means applies frictional force in a first direction of the two directions by rotation of the rotating means itself; In the direction, the rotating means is a rotating means that applies a frictional force by the movement of the rotating means itself.

The sheet feeding means includes a rotating means, and a moving means for moving the rotating means itself in a direction along the sheet at a predetermined angle with the rotation direction of the rotating means.

An image reading apparatus, comprising: a document feeder provided with the above-mentioned sheet feeding device; and an image reading portion for reading an image on a document fed from the document feeder. It is characterized by.

An image forming apparatus, comprising: a recording material feeding unit provided with the above-mentioned sheet feeding device; and an image forming unit for forming an image on a recording material fed from the recording material feeding unit. It is characterized by having.

[0036]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(Embodiment 1) In FIGS. 1 and 2 showing a sheet feeding apparatus according to a first embodiment of the present invention, a sheet feeding means 1 is suspended around belt shafts 10 and 11. And an endless belt 8 made of an elastic body, and a rotating member 2 as a contact moving means which moves along the sheet while being inscribed in the endless belt 8 and urging the endless belt 8 to contact the sheet. And a pick roller 12 as a rotating roller is provided at a portion of the rotating member 2 that is in contact with the belt 8.

The pick roller 12 is provided rotatable about the shaft 4. At both ends of the shaft 4, there are bearings 5 slidable in the grooves of the arms 9, and the bearings 5 are pressed downward by springs 6. The arm 9 includes the arm shaft 3
The arm shaft 3 is rotatably attached to a frame of a main body (not shown).
A gear 13 is provided at an end of the arm shaft, and meshes with a gear 14 of the motor 7.

The operation of the sheet feeding means will be described with reference to FIGS. 1 and 2A to 2E.

The state before paper feeding is (a). When the paper feeding operation is started, the motor 7 rotates, and the arm shaft 3 starts rotating by the connection of the gears. The rotation of the arm shaft 3 causes the pick roller 12 to be in contact with the belt 8, urges the belt 8 while rotating the pick roller 12 itself, and abuts on the uppermost document P ₁ . Its state is shown (b), the marked marks ▼ to abutment against the document P ₁ of the uppermost layer, referred to ▲ mark the position for the original P ₂ of the second layer.

[0041] As rotation advance original P ₁ of the belt 8 is fed by the feeding speed V _P, is set at the same velocity V _a, when the belt 8 is in contact with the document surface, the document paper feed Operation starts. Further, when the arm 9 rotates and the pick roller 12 rotates, the bearing 5 for supporting the central shaft 4 thereof.
But it continued feeding of the document P ₁ while sliding relative to the arm 9 (c).

The arm 9 continues to rotate, and the belt 8
The feeding of the original by the belt 8 is continued until it is separated from ₁ (d). The mark ▼ to position on the document P ₁ of the uppermost point of the time belt leaves the document referred to ▲ mark the position for the original P ₂ of the second layer.

Thereafter, the pick roller 12 keeps rotating while abutting on the belt on the side opposite to the document surface (e), and returns to the standby state of (a) with one rotation.

[0044] By this operation, the belt 8 contacts the document P ₁ of the top layer, its the absolute position (position on the document P ₂₎ is displaced a range of L _2, the original P ₁ the relative positions displaced a range of L _1. For this reason,
Backside of the image T of the original P ₁ as in the prior art, always document P ₂
It is pressed against the upper point by the pressure P, and does not move by being rubbed.

Therefore, even if an image is formed on the back side of the uppermost document, the paper feeding operation is performed while the portion pressed against the next document surface moves, so that the dirt is not concentrated on a very narrow area. It becomes very slight, and no trouble occurs when the same original is read again. Further, since there is no need to lower the contact pressure of the belt against the sheet, stable sheet feeding performance can be secured.

(Embodiment 2) In FIGS. 3 and 4 showing a sheet feeding apparatus according to a second embodiment of the present invention, the sheet feeding means 21 has a pick-up roller 33 as a rotating means. A swing arm 32 and a motor 3 serve as first swing means for swinging the rotation shaft 36 substantially in parallel with the document S.
4, a swing shaft 3 of the first swing means, comprising a gear 35 and a shaft 39.
As a second swing means for swinging the document 9 substantially perpendicular to the document S, a motor 30, a drive belt 29, a shaft 28, and a swing support lever 27 are provided. The pickup roller 33 is rotatable by the driving force of the driving motor 26 via the driving belts 25, 24, 31.

The swing support lever 27 is swingable by a stepping motor 30 via a drive belt 29. By swinging about a shaft 28, the arm 22 can be pushed upward. . Arm 22
Swings about the shaft 23 when pushed upward by the swing support lever 27.

A gear portion 32 a is provided on a part of the swing arm 32, and meshes with a gear 35 of the motor 34. Since the swing arm 32 is configured to be swingable about a shaft 39, a motor 34
The position is controlled so as to be swingable by the operation described above.

The pickup roller 33 is driven by the drive belt 2.
The motor can be rotated by the driving force of the driving motor 26 via 5, 24, 31.

The pickup rollers 33 are provided at both ends of the rotation center shaft 36.
The swing arm 32 is rotatably supported by a bearing 37.

FIGS. 3 and 4 (a) to 4 (a) show the operation when feeding paper.
This will be described with reference to FIG.

(A) is a paper feed standby state. When the sheet feeding operation is started, the swing arm 32 is rotated by the motor 34. When the swing arm 32 rotates, the pickup roller 33 comes into contact with the uppermost sheet of the stacked document (b).

At this time, the motor 26 operates, the pickup roller 33 starts rotating by the connection of the driving, and the feeding of the document is started. At the same time as the feeding is started, the swing arm 32 starts to rotate again.

[0054] Thus the pickup roller 33 is moved at a velocity V _P in the direction of the arrow in FIG. As it moves, the arm 22 is lifted up slightly about the central axis 23.

[0055] If the feeding speed at this time the document is represented by V _P, the rotational speed V _a of the pickup roller
, Taking into account the movement speed component of the pickup roller, as an absolute value, is set such that a _{V a = V P + V R} .

When the rotation of the swing arm 32 further advances and the pickup roller separates from the document, the feeding of the document by the pickup roller 33 ends (d).
The sheet is separated and fed by a separation roller pair (not shown).

When the feeding of the original is completed, the pickup roller is lifted to the retreat position together with the arm 22 by the operation of the motor 30. In that state, the motor 3
By returning the swing arm 32 to the original position by 4 and lowering the arm 22 again by the operation of the motor 10, the state returns to the standby state (a).

With such an operation, the pickup roller 33 and the uppermost original P are moved in the same manner as in the first embodiment.
Contact with _1, for its absolute position (position on the document P ₂₎ is displaced a range of L _2, the relative position between the original P ₁ is displaced a range of L _1. Therefore, the image T on the back of a conventional way the original P ₁ is always at one point on the document P _2, pressed by the pressure P, not move being rubbed.

Therefore, even if an image is formed on the back side of the uppermost document, the paper feeding operation is performed while the portion pressed against the next document surface moves, and the dirt is not concentrated on a very narrow area. It becomes very slight, and no trouble occurs when the same original is read again. Further, since there is no need to lower the contact pressure of the belt against the sheet, stable sheet feeding performance can be secured.

[0060] Incidentally, in the first embodiment and the present embodiment, the moving direction of the contact point between the means and the document P ₁ sheet feeding is, although the opposite direction to the sheet feeding direction, in the same direction There may be.

In the second embodiment, assuming that the rotation speed of the pickup roller 33 is V _a , the moving speed of the contact point between the pickup roller 33 and the document P ₁ is V _r , and the feeding speed of the document is V _p , V _a by setting the + V _r = V _p V _a and V _r so that the relationship is satisfied, it is possible to obtain the same effect.

[0062] However, in the first embodiment, if the moving speed of the rotational speed and Pikkukoro 22 of the belt 8 are the same, the contact between the belt 8 and the document P _1, the relative position with respect to the original P ₁ there not displaced, resulting in soiling the image of the surface of the original P ₂ is rubbed on the back narrow area of the original P _2. To prevent this, these speeds must be different.

(Embodiment 3) In FIG. 5 showing a sheet feeding apparatus according to a third embodiment of the present invention, the sheet feeding means is a pickup roller 55 as a rotating means.
And a motor 51, a pinion gear 52, and a rack 53 as moving means for moving the pickup roller 55 itself in a direction forming a predetermined angle (90 °) with the rotation direction of the pickup roller 55 along the document S. It has become.

The pickup roller 55 is rotatably mounted on the arm 42, and the arm 42 is mounted on the shaft 43 so as to be swingable. Further, the pickup roller 55 is rotatable by the driving force of the driving motor 46 via the driving belts 45 and 44. Further, the swing support lever 47 is swingable about a shaft 48, and the swing support lever 47 can push up the arm 42 to swing. The swing support lever 47 is swingable by a stepping motor 50 via a drive belt 49.

The pickup roller 55 is provided at both ends of a rotation center shaft 56, and the rotation center shaft 56 is rotatably supported on the arm 42 by a bearing 57. The rotation of the pickup roller 55 is performed by a motor 46 that is drivingly connected.
It is controlled by the motor 50. The vertical movement of the arm 42 allows the pickup roller 55 to freely control contact and separation with the document S.

The arm 42 is provided with a rack 53, which is provided with a pinion gear 52 provided on the motor 51.
And are engaged. Since the motor 51 is fixed to a main body frame (not shown), the motor 51 includes the arm 42 and the pickup roller 55 by the operation of the motor 51. The paper feeding device slides with respect to the main body in the directions of arrows X and Y in the figure.

The entire paper feeder is mounted at an angle θ with respect to the feed direction of the document S.

That is, the slide movement of the paper feeder by the motor 51 described above is performed by 90
It is configured to move in a direction inclined by ° -θ.

In the standby state, the arm 42 is lifted upward.
Operates, and the pickup roller 55 comes into contact with the document.

Next, the pickup roller 55 is rotated by the motor 46. The roller rotation speed at this time is V _a.

At the same time as the pickup roller 55 starts rotating, the motor 51 starts operating, and the pickup roller 55 moves together with the arm 42 in the direction of the arrow X in the figure. The movement speed at this time is V _R.

[0072] the movement speed V _R in the lateral direction of the pickup roller, the direction in which the sum of the feeding speed V _a for the original of the pickup roller, the document will be transported at a speed.

[0073] When the speed of the document conveyed from the apparatus body to V _{P, these, V P, V R, V} a is such that a relationship shown in the drawing vector, its magnitude is set ing.

When the paper feeding operation is completed and the original is conveyed by the next separation roller (not shown), the arm 42 is lifted up by the operation of the motor 50, whereby the pickup roller 55 is also separated from the original surface. The motor 51 slides the arm 42 in the direction of the arrow Y in the state of being lifted up, and returns to the original paper feed standby state.

[0075] Also in this embodiment, the first and second be the embodiment similar to the image on the back side of the uppermost original P ₁ is formed, portions for pressing the face of the next original P ₂ Since the paper feeding operation can be performed while moving, the dirt becomes extremely light, and no trouble occurs when the same document is read again. Also, since there is no need to lower the contact pressure of the pickup roller with respect to the original, stable paper feeding performance can be ensured.

(Other Embodiments) Also,
The sheet feeding device described in the third embodiment can be applied to an image forming device or an image reading device.

In this case, by providing a recording material feeding section provided with the sheet feeding device of the present application, and an image forming section for forming an image on the recording material fed from the sheet feeding section, It is possible to provide a high quality image forming apparatus that does not impair the quality of the recording material when the recording material is fed by the recording material feeding unit. It should be noted that a portion other than the recording material feeding portion, such as an image forming portion provided in the image forming apparatus, may be appropriately applied with a conventional configuration, and a detailed description thereof will be omitted.

Similarly, according to the provision of the document feeder provided with the sheet feeder and the image reading section for reading the image of the document fed from the document feeder, the document feeder is also provided. It is possible to provide a high-quality image reading apparatus that does not impair the quality of a document when the document is fed by the feeding unit. In this case as well, the portions other than the document feeding section may appropriately apply the conventional configuration.

[0079]

According to the present invention, since the contact point between the sheet feeding means and the uppermost sheet is displaced both in the relative position and the absolute position with respect to the uppermost sheet, the sheet is fed. In doing so, the sheet feeding means applies pressure to the uppermost sheet and also to the lower layer sheet over a certain range, so that the range in which those sheets are in sliding contact with each other is also widened, Sheet contamination due to the image of one sheet rubbing on a narrow area of the other sheet can be prevented. At this time, since it is not necessary to reduce the pressure applied to the sheet, the feeding operation does not become unstable.

That is, it is possible to provide a high-quality sheet feeding apparatus capable of maintaining the quality of sheets during feeding.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory perspective view of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of the sheet feeding device according to the first embodiment of the present invention.

FIG. 3 is a schematic explanatory perspective view of a sheet feeding device according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating an operation of a sheet feeding apparatus according to a second embodiment of the present invention.

FIG. 5 is a schematic explanatory perspective view of a sheet feeding device according to a third embodiment of the present invention.

FIG. 6 is an explanatory diagram of a conventional sheet feeding apparatus.

FIG. 7 is a perspective view of a conventional sheet feeding apparatus.

FIG. 8 is a diagram illustrating the operation of a pickup roller of a conventional sheet feeding device.

[Explanation of symbols]

 1, 21, 41 Sheet feeding means 2 Rotating member 8 Endless belt 12 Pick roller 22, 42 Arm 32 Swing arm 33, 55 Pickup roller 52 Pinion gear 53 Rack S Sheet

Claims (11)

[Claims] 1. A sheet feeding device using a sheet feeding means for applying a conveying force while abutting on an uppermost sheet among sheets placed on a sheet mounting table, wherein the sheet feeding means is provided. A contact point between the sheet and the uppermost layer sheet is displaced both in a relative position and an absolute position with respect to the uppermost layer sheet. 2. A sheet feeding means comprising: an endless belt made of a stretched elastic body; and an urging member which is inscribed in the endless belt and in which the endless belt is brought into contact with the sheet. Contact moving means moving along the sheet while moving the endless belt and the sheet relative to the sheet, the relative position of the contact between the endless belt and the sheet is displaced by the rotation of the endless belt itself, and the absolute position is determined by the contact moving means. The sheet feeding device according to claim 1, wherein the sheet feeding device is displaced. 3. The contact moving means is a rotating member that rotates about an axis provided inside the endless belt, and a rotating roller is provided at a portion of the rotating member that is inscribed in the belt. The sheet feeding device according to claim 2, wherein: 4. The sheet feeding apparatus according to claim 2, wherein a contact moving direction of the contact moving means is opposite to a sheet feeding direction. 5. The apparatus according to claim 1, wherein said sheet feeding means includes a rotating means which comes into contact with the sheet, and wherein the conveying force is a combined force of a friction force caused by rotation of the rotating means itself and a friction force caused by movement of the rotating means itself. The sheet feeding device according to claim 1, wherein 6. The sheet feeding means includes: the rotating means; a first swinging means for swinging a rotating shaft of the rotating means substantially parallel to the sheet; and a swinging axis of the first swinging means. A second swinging means for swinging the sheet substantially perpendicular to the sheet; a first and a second swinging means for moving an absolute position of a contact point between the rotating means and the sheet in parallel with the sheet during sheet feeding; The oscillating means is operated, and after the sheet is fed, the rotating means is separated from the sheet by the second oscillating means, and is returned to a position before feeding by the first oscillating means. 6. The sheet feeding device according to 5. 7. The sheet feeding apparatus according to claim 6, wherein the absolute position of the contact point between the rotating means and the sheet is moved in a direction opposite to a sheet feeding direction. 8. The sheet feeding means is in contact with a sheet,
Rotating means for applying frictional force in two independent directions on the sheet surface, wherein the rotating means applies frictional force in a first direction of the two directions by rotation of the rotating means itself; 2. A rotating means for applying a frictional force by the movement of the rotating means itself in the direction of (1).
3. The sheet feeding device according to 1. 9. The sheet feeding means includes: the rotating means; and moving means for moving the rotating means itself in a direction along the sheet at a predetermined angle with respect to the rotating direction of the rotating means. The sheet feeding device according to claim 8, wherein 10. A document feeder provided with the sheet feeding device according to claim 1, and an image for reading an image on a document fed from the document feeder. An image reading apparatus, comprising: a reading unit. 11. A recording material feeding section provided with the sheet feeding device according to any one of claims 1 to 9, and an image formed on a recording material fed from the sheet feeding device. An image forming apparatus, comprising: an image forming unit that forms an image.