JP2002240971A - Paper feed mechanism and imaging device provided with this paper feed mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of a collision sound of a gear at paper feed time, and eliminate even carelessly coming off of a hook part of a cam unit from a pawl lever. SOLUTION: In this paper feed mechanism, a cam unit 15 is supported capable of relatively turning to a paper feed roller shaft 2 fixedly mounting a paper feed roller 1, to stop rotation of the cam unit 15 by a pawl lever, the cam unit 15 is rotated by one turn in an equal direction to the paper feed roller shaft 2 when stopping by this pawl lever is released, so as to feed one sheet of paper. The paper feed mechanism is provided with a coil spring 17, between the cam unit 15 and the paper feed roller shaft 2, as a torque limiter mechanism connecting the cam unit 15 and the paper feed roller shaft 2 by prescribed torque.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed mechanism for feeding paper one sheet at a time by a paper feed roller, and an image forming apparatus such as a plain paper copier, various printers, and a facsimile machine equipped with the paper feed mechanism. About.

[0002]

2. Description of the Related Art Image forming apparatuses using an electrophotographic method, such as a plain paper copying machine, various printers, and facsimile machines, have recently been required to have lower cost and lower noise. In response to this demand, a low-cost product has been realized by simplifying the drive mechanism of the paper feeding unit inside the image forming apparatus. As a conventional paper feeding mechanism in such an image forming apparatus, for example, there is one as shown in FIG.
FIG. 25 shows a drive mechanism of the cam unit.

First, such a paper feed mechanism will be briefly described with reference to FIGS. 24 and 25. In FIG. 24, a passive gear 3 is attached to the end of the paper feed roller shaft 2 to which the paper feed roller 1 is fixed.
Are fixed, and the passive gear 3 is engaged with the pinion 4 a of the drive gear 4. The drive gear 4 is rotated in the direction of arrow A by the driving force from a main motor (not shown), whereby the paper feed roller 1 is always rotated in the direction of arrow B together with the passive gear 3 and the paper feed roller shaft 2.

A cam unit 5 is inserted into the paper feed roller shaft 2 in the vicinity of the passive gear 3 so as to be relatively rotatable. The cam unit 5 is integrally formed with a first cam 5a, a second cam 5b, a hook portion 5c, a sector gear 5d, and a torsion spring contact portion 5e shown in FIG.
Then, as shown in FIG. 25, one end of the torsion spring 6 comes into contact with the torsion spring contact portion 5e and presses in the direction of arrow C to apply a rotational force to the cam unit 5 in the direction of arrow D at all times. I have. However, since the hook portion 5c is engaged with the pawl lever 7, the rotation of the cam unit 5 is stopped, and the portion of the sector gear 5d having no teeth is the pinion portion 4a.
Are not engaged with the pinion portion 4a, and are not rotated by the drive gear 4.

The pawl lever 7 is supported by a support shaft 9 and is urged by a spring 8 in a direction to engage with the hook 5c. The movable piece 14a of the solenoid 14 is hooked at an intermediate portion of the claw lever 7. Although not shown, sheets are stacked on the tray bottom plate 10 shown in FIG. 24, and the bottom plate spring 11 constantly urges the tray bottom plate 10 in a direction to approach the paper feed roller 1. However, when the cam unit 5 is in the stop state shown in the figure,
The projection 10a is pushed back by the first cam 5a, and the tray bottom plate 10 retreats, so that the paper thereon does not come into contact with the paper feed roller 1.

The friction pad 1 shown in FIG.
2 is also urged by the friction pad spring 13 in a direction approaching the paper feed roller 1, but when the cam unit 5 is in the stop state shown in the drawing, the second cam 5b
As a result, the projection 12a is pushed back, and the friction pad 12 is held apart from the paper feed roller 1. Therefore, in this state, even if the paper feed roller 1 is rotating, the paper is not pressed against the paper feed roller 1 and the paper is not fed.

When a sheet feed signal is sent from a control unit (not shown), a short-time voltage is applied to the solenoid 14. The excitation of the solenoid 14 at that time causes the movable piece 14a to move in the direction indicated by the arrow E, and the claw lever 7 to rotate in the direction indicated by the arrow E in FIG. Disengage. Thereby, the cam unit 5
25 rotates vigorously in the direction of arrow D in FIG. 25 by the urging force of the torsion spring 6, the sector gear 5 d rotates in the same direction (direction of arrow G), and its tooth portion moves in the direction of arrow H of the drive gear 4. The rotating gear collides with and engages with the rotating pinion portion 4a, and the rotational force of a main motor (not shown) is transmitted from the driving gear 4 to the cam unit 5 via the sector gear 5d, and the cam unit 5 makes one rotation in the direction of arrow D.

[0008] By the rotation of the cam unit 5, FIG.
The first cam 5a and the second cam 5b shown in FIG. 3 also rotate together to release the depressions of the projections 10a and 12a, so that the tray bottom plate 10 is pushed up by the bottom plate spring 11 so as to approach the paper feed roller 1, and The paper loaded on the upper surface is brought into contact with the paper feed roller 1. At this time, the friction pad 12 is also pushed up by the friction pad spring 13 and comes into contact with the paper feed roller 1.
Therefore, the uppermost sheet is fed toward the friction pad 12 by the rotation of the sheet feed roller shaft 2 in the direction indicated by the arrow B, and is further fed while being sandwiched between the sheet feed roller 1 and the friction pad 12. Even if a plurality of sheets are fed between the paper feed roller 1 and the friction pad 12, since the frictional force between the paper feed roller 1 or the friction pad 12 and the paper is larger than the frictional force between the papers,
Only the top sheet passes through it and is fed.

When the cam unit 5 makes one revolution, the sector gear 5d is replaced with a toothless portion by the pinion portion 4 of the drive gear 4.
It comes to the position corresponding to a, and stops because it does not receive the rotational force. At the same time, the hook portion 5c is engaged and stopped by the pawl lever 7, and is held at that position. When the cam unit 5 completes one rotation and stops, the tray bottom plate 10 and the friction pad 12 are also returned to their original positions by the first cam 5a and the second cam 5b, and are separated from the paper feed roller 1. This series of operations is performed when one sheet of paper is fed, and is repeated for each paper feed.

[0010]

However, in such a driving mechanism of the paper feeding unit, when the pawl lever 7 is disengaged from the hook 5c of the cam unit 5, the cam unit 5 is urged by the force of the torsion spring 6. As a result, the tooth portion of the sector gear 5d collides with the tooth surface of the drive gear 4 and meshes with the tooth surface of the drive gear 4, thereby generating a loud collision sound. Further, since the cam unit 5 is constantly rotating by the biasing force of the torsion spring 6, an impact or the like is applied when the image forming apparatus is stored or transported, and the hook portion 5c is disengaged from the claw lever 7. If this occurs, there is also a problem that the cam unit 5 rotates.

Further, in the conventional paper feeding mechanism adopting such a separation system, especially in the case of a low-priced low-speed machine of 10 PPM (image forming speed is 10 sheets per minute) or less, the paper feeding roller Since abnormal noise due to sticking slip occurs during transport due to the paper sandwiched between the friction pads, it is necessary to take measures to make the paper feed roller half-moon-shaped. Therefore, it is necessary to provide an extra cylindrical collar having a diameter smaller than the diameter of the paper feed roller for limiting the rise of the tray bottom plate coaxially with the paper feed roller, resulting in an increase in the number of parts and an increase in production cost. Becomes

Recently, with the increase in the use of recycled paper, the leading end of the paper, such as postcards and envelopes, in the transport direction of the paper is often flared or burrs are generated during cutting. There is also a problem that the friction pad method tends to cause non-feeding of the sheet due to a transport load.

Further, the use of the backing paper is increasing due to the reuse of the copy paper, and the friction coefficient between the stacked papers may vary, which may cause a double feed. Depending on the curl direction, the paper may be curled, and depending on the direction of the curl, a load may be applied to the leading end of the paper at the paper separation portion, or the paper may not be conveyed to the separation portion and may not be fed.

In the above-described system in which the friction pad is provided, since the flat portion of the pad is pressed against the paper feed roller, the transport direction of the paper fed from the stacked state (to the displacement angle of the tray bottom plate or the like). The angle of the friction pad must be within a predetermined range with respect to (corresponding to), for which the roller diameter of the paper feed roller is limited and the size of the paper feeder is reduced due to the restriction of the layout freedom. There is also a problem in that it cannot be achieved.

On the other hand, in the case of the bank separation system,
Japanese Patent No. 1612 discloses a gate member in contact with a paper feed roller, the upper edge portion of which is flat, the nip portion with the paper feed roller is wide, and the inclined surface thereof is formed at a predetermined inclination angle due to variations in the members. It is difficult to arrange them. Further, such a gate member is usually formed of a synthetic resin material,
When the number of passed sheets increases due to friction with the leading edge of the paper, abrasion occurs, and the inclination angle changes by the amount of the abrasion, and the predetermined angle cannot be maintained. May occur.

Further, while the uppermost sheet is usually conveyed by the image forming section, the feed roller is not driven, but while the preceding sheet is nipped between the feed roller and the gate member, When the trailing edge of the preceding sheet passes through the nip portion, the leading edge of the next sheet is sent to the gate member by the rotating of the sheet feeding roller.

At this time, the coefficient of friction between the sheets is high or large, and the coefficient of friction between the next sheet and the next sheet is lower than the coefficient of friction between the preceding sheet and the next sheet. In such a case, the next sheet may get over the gate member, resulting in a double feed. In addition, in the bank separation method, it is necessary to add a brake member made of a thin plate-like elastic material in order to cope with a wide range of flexural modulus of various kinds of paper, and the number of parts and assembling man-hours increase, thereby reducing production cost. There was also a problem that led to a rise.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is intended to prevent a gear collision sound from being generated during paper feeding in a paper feeding mechanism of an image forming apparatus. An object of the present invention is to prevent a hook portion from being accidentally detached from a claw lever. It is another object of the present invention to reduce the cost and space of the paper feed mechanism and the image forming apparatus including the paper feed mechanism. It is another object of the present invention to provide a paper feed mechanism capable of reliably separating and conveying a variety of sheets one by one without non-feeding or double feeding, and an image forming apparatus including the same.

[0019]

In order to achieve the above object, a paper feed mechanism according to the present invention has a paper feed roller, a paper feed roller shaft to which the paper feed roller is fixed, and a paper feed roller shaft. A cam unit rotatably supported, a claw lever for stopping the rotation of the cam unit, a solenoid for rotating the claw lever in a direction away from the hook of the cam unit, and a rotation of the paper feed roller shaft And a driving gear for rotating the passive gear. When the solenoid operates, the pawl lever is disengaged from the cam unit, and the cam unit makes one rotation in the same direction as the paper feed roller shaft. The cam portion allows the tray bottom plate to contact the paper feed roller, and allows the friction pad to abut the paper feed roller to feed one sheet of paper. In the paper feed mechanism, between the cam unit and the paper feed roller shaft, it is provided with a torque limiter mechanism for connecting its cam unit and the sheet feeding roller shaft at a predetermined torque.

Alternatively, instead of the friction pad, an inclined surface with which the front end in the sheet feeding direction abuts is formed, and a contact surface with the paper feed roller is formed as a ridge along the axial direction of the paper feed roller. May be provided. The inclined member preferably has parallel moving means for moving the sheet in parallel with the sheet feeding roller. It is preferable that the length of the contact surface of the inclined member is smaller than the length of the feed roller in the axial direction. The inclined member is formed of synthetic resin, and at least the contact surface with the feed roller is formed. It is more preferable to cover with an elastic metal plate. Further, the distance along the sheet conveyance direction between the portions where the sheets stacked on the inclined member and the sheet stacking member are pressed against the sheet feed roller is set to 2 mm to 6 mm, and the sheet on the inclined surface of the inclined member is set. The angle with respect to the transport direction is preferably set to 50 ° to 70 °.

In these paper feed mechanisms, the torque limiter mechanism is inserted into the paper feed roller shaft to generate a frictional force between the paper feed roller shaft and an outer peripheral surface of the paper feed roller shaft, and one end of the paper feed roller shaft is provided with the cam unit. It is good to be constituted by the coil spring locked in. Further, a spring storage chamber for storing the coil spring may be provided in the cam unit. Further, it is desirable that at least a region of the outer peripheral surface of the feed roller shaft that slides with the coil spring be hardened by induction hardening. Alternatively, grease may be applied to at least a region of the paper feed roller shaft that slides with the coil spring, and at least a part of the spring storage chamber may be filled with grease.

The torque limiter mechanism comprises a sliding member which is inserted into the paper feed roller shaft and slidably contacts an end surface of the cam unit, and a compression spring which presses the sliding member against the end surface of the cam unit. The predetermined torque may be generated by a friction load between the unit and the sliding member. Furthermore, in these paper feed mechanisms, the cam unit is provided with a sector gear portion that can mesh with a drive gear, and when the rotation of the cam unit is stopped by a pawl lever, the sector gear portion is
The toothless portion may be in a non-meshing position corresponding to the drive gear. An image forming apparatus according to the present invention includes:
The paper feed mechanism is provided with an image forming unit that forms an image on paper fed by the paper feed mechanism.

[0023]

Embodiments of the present invention will be specifically described below with reference to the drawings. Since the basic configuration and functions of the paper feed mechanism described below are common to the above-described conventional paper feed mechanism, description of the common parts will be omitted.
In the drawings used below, the same parts as those in FIGS. 24 and 25 are denoted by the same reference numerals.

First, a first embodiment of the paper feeding mechanism according to the present invention will be described with reference to FIGS. Figure 1
FIG. 2 is an exploded perspective view of a member attached to a paper feed roller shaft in the paper feed mechanism, and FIG. 2 is a cross-sectional view along the axial direction in the assembled state. 3 and 4 are views seen from opposite sides for explaining the driving mechanism of the cam unit. 1 and 2, a paper feed roller 1 and a passive gear 3 are fixed to a paper feed roller shaft 2, and the paper feed roller shaft 2
A D-cut portion 2c is formed at one end of the D-shaped portion, and a D-hole 3a of the passive gear 3 is fitted into the D-cut portion 2c, and is fixed so as to rotate integrally by D-cut coupling. The passive gear 3 is shown in FIG.
Similarly to the sheet feeding mechanism shown in FIG. 4, the sheet is rotated while being engaged with a driving gear rotated by a main motor, whereby the sheet feeding roller shaft 2 and the sheet feeding roller 1 are constantly rotating.

A cam unit 15 is mounted on the paper feed roller shaft 2.
Are rotatably supported, and the cam unit 15
Are the first cam 15a, the second cam 15b, and the hook 15c.
Are formed integrally, and a spring accommodating chamber 15d having a larger diameter than the shaft hole is formed inside, and grease 16 is applied to the inner end surface at the inner side thereof, so that the inner diameter is close to the diameter of the feed roller shaft 2. The wound coil spring 17 is inserted into the paper feed roller shaft 2 and stored in the spring storage chamber 15 d, and the hook portion 17 a at one end thereof is provided in the locking groove 1 provided in the cam unit 15.
The torque limiter mechanism is configured by being fitted into and locked to 5e. A substantially cam unit 15 is provided on the feed roller shaft 2.
E-ring grooves 2a and 2b are formed at intervals of the length of E. The E-ring 19 is fitted into the E-ring groove 2a, and the E-ring 19 is inserted through the washer 18 with the cam unit 15 interposed therebetween.
The E-ring 20 is fitted into the ring groove 2b, and holds the cam unit 15 and the coil spring 17 so as not to move in the axial direction on the paper feed roller shaft 2.

It is desirable that at least a region of the paper feed roller shaft 2 which slides with the coil spring 17 is hardened by induction hardening. Grease is applied to at least a region of the paper feed roller shaft 2 that slides with the coil spring 17, and as shown in FIG.
Grease 16 may be filled in a part of the grease. The drive mechanism of the cam unit 15 in the paper feed mechanism configured as described above will be described with reference to FIGS. This cam unit 15
The hook portion 15c is always locked to the pawl lever 7 as in the case of the above-described conventional example.

This paper feeder does not have a drive motor unique to paper feed, and the drive source is a main motor. When a recording command is issued to the image forming apparatus, the main motor rotates, and the drive driven by the main motor rotates. Power is transmitted from the gear, and the passive gear 3 shown in FIG. 4 is rotated only in the direction of arrow I by the rotation of the pinion portion 4a of the drive gear in the direction of arrow H. As a result, the feed roller shaft 2 rotates in the direction of arrow D, and the coil spring 17 shown in FIG. 3 also tries to rotate in the direction of arrow, but since the rotation of the cam unit 15 is prevented, the coil spring 17 Hook part 1
7a pushes the end of the locking groove 15e of the cam unit 15,
The coil spring 17 is loosened (the winding diameter is slightly increased) by the force, and the coil spring 17 is idled at a predetermined torque. That is, the torque limiter mechanism is a spring clutch mechanism.

Therefore, even if the paper feed roller shaft 2 is rotating, the cam unit 15 is also idlely stopped because the coil spring 17 idles with respect to the paper feed roller shaft 2. The idling torque at this time is determined by the inner diameter of the coil spring 17 and the diameter of the feed roller shaft 2, and in this example, was about 500 gr · cm. When a voltage is applied to the solenoid 14, the movable piece moves in the direction of arrow E shown in FIG. 4, and the pawl lever 7 is turned in the direction of arrow F to disengage from the hook portion 15c of the cam unit 15. As a result, the cam unit 15 including the hook 15c rotates in the direction indicated by the arrow due to the rotational torque received from the coil spring 17. At this time, the coil spring 17 is tightened (the winding diameter is reduced), rotates integrally with the paper feed roller shaft 2, and the cam unit 15 is also pushed by the hook 17a and rotates integrally.

When the voltage of the solenoid 14 is turned off,
The pawl lever 7 is rotated by the force of the spring 8 to abut on the peripheral surface of the hook portion 15c of the cam unit 15, and the cam unit 1
When 5 rotates once, it engages with its hook 15c to stop its rotation. The mechanism and operation for feeding one sheet of paper by one rotation of the cam unit 15 are shown in FIG.
Is the same as the conventional paper feed mechanism described above. As described above, since the cam unit 15 of the paper feeding mechanism of this embodiment does not have a gear portion corresponding to the sector gear 5d of the cam unit 5 of the conventional paper feeding mechanism shown in FIGS. Is not generated when the cam unit 15 starts rotating by detaching from the hook portion 15c.

Conventionally, even when the paper feed roller shaft 2 is not rotating and the cam unit is not in operation, the cam unit is always rotated by the torsion spring. When the lever is released, the cam unit 15 may rotate when the paper feed roller shaft 2 is stopped. In this embodiment, the cam unit 15 is held at a predetermined torque by the torque limiter mechanism.
Since the pawl lever 7 does not receive the rotational force, it does not rotate even if the pawl lever 7 comes off from the hook portion 15c.
When is returned, it is locked again. Therefore, unlike the conventional sheet feeding mechanism, the cam unit is inadvertently rotated due to the release of the pawl lever, which causes a problem that the cam unit suddenly rotates to start sheet feeding at the next start. There is no.

Next, a second embodiment of the paper feeding mechanism according to the present invention will be described with reference to FIGS. FIG.
FIG. 6 is an exploded perspective view of a member attached to a paper feed roller shaft in the paper feed mechanism, and FIG. 6 is a cross-sectional view along the axial direction in the assembled state, and the same parts as those in FIGS. Reference numerals are used, and their description is omitted. The cam unit 25 in this embodiment also has a first cam 25a, a second cam 25b, and a hook portion 25c integrally formed, but the cam unit 25 in the first embodiment that corresponds to the spring storage chamber 15d is the same. Not formed,
It has a solid shape and its rear end face is flat. The first cam 25a, the second cam 25b, and the hook 25c of the cam unit 25 perform the same functions as the first cam 15a, the second cam 15b, and the hook 15c of the cam unit 15 in the first embodiment. .

The sliding cylinder 26 serving as a sliding member is moved so that the sliding plate 26a comes into contact with the rear end surface of the cam unit 25.
Is inserted into the feed roller shaft 2, a compression spring 27 is inserted around the outer periphery of the feed roller shaft 2, and a passive gear 3 is inserted into a D-cut portion 2 c at the tip of the feed roller shaft 2, thereby forming the feed roller shaft 2. E-rings 19, respectively in the E-ring grooves 2a, 2d
21 is fitted. As a result, the compression spring 27 is compressed by the sliding plate 26a of the sliding cylinder 26 and the passive gear 3, and presses the sliding plate 26a against the rear end surface of the cam unit 25, thereby constituting a torque limiter mechanism. .

Therefore, when the passive gear 3 rotates and the paper feed roller shaft 2 and the paper feed roller 1 rotate, the cam unit 2
5 also tries to rotate in the same direction by coupling with a predetermined torque due to a frictional load with the sliding cylinder 26. However, FIGS. 3 and 4
In the same manner as in the example shown in FIG.
Is locked, the cam unit 25 slips and stops. When the hook (25c) is disengaged from the hook lever 25c by energizing the solenoid (not shown), the cam unit 25 rotates once in the rotation direction of the passive gear 3 with a predetermined torque due to the friction load of the torque limiter mechanism described above. It is locked again by the pawl lever and stops. One sheet is fed by the feed roller 1 by one rotation of the cam unit 25, as in the case of the above-described conventional sheet feeding mechanism.

According to this embodiment, the cam unit 2
5 does not have a gear portion corresponding to the sector gear of the conventional cam unit, so that no collision sound is generated when the cam unit 25 starts rotating by the hook lever being disengaged from the hook portion 25c. In addition, there is no inconvenience that the cam unit is inadvertently rotated due to the release of the lever, and the cam unit is suddenly rotated at the next start and paper feeding is started. This is the same as in the embodiment.

Next, a third embodiment of the paper feeding mechanism according to the present invention will be described with reference to FIGS. FIG.
FIG. 8 is an exploded perspective view of a member attached to a paper feed roller shaft in the paper feed mechanism. FIG. 8 is a cross-sectional view along the axial direction in the assembled state, and the same parts as those in FIGS. Reference numerals are used, and their description is omitted. The cam unit 35 in this embodiment includes a first cam 35a, a second cam 35b, a hook 35c, and a sector gear 35.
d is formed integrally, and further on the rear end side thereof, the spring storage chamber 1 in the cam unit 15 of the first embodiment is provided.
A storage chamber 35e having a diameter smaller than 5d and larger in diameter is formed.

The first cam 35a of this cam unit 35,
The second cam 35b and the hook 35c are connected to the first cam 15a, the second cam 15a of the cam unit 15 in the first embodiment.
It has the same function as the cam 15b and the hook 15c.
Then, a sliding cylinder 36 as a sliding member is inserted into the feed roller shaft 2 so that the sliding plate portion 36a comes into contact with the inner end surface of the storage chamber 35e of the cam unit 35, and a compression spring is 37, and the passive gear 3 is further inserted into the D-cut portion 2c at the leading end of the feed roller shaft 2, and E-rings 19, 21 are respectively inserted into E-ring grooves 2a, 2d formed in the feed roller shaft 2. It is inserted.

As a result, the compression spring 37 is compressed by the sliding plate portion 36a of the sliding cylinder 36 and the passive gear 3, and presses the sliding plate portion 36a against the inner end surface of the cam unit 35 to constitute a torque limiter mechanism. ing. for that reason,
When the passive gear 3 rotates, the feed roller shaft 2 and the feed roller 1
Is rotated, the cam unit 35 also tries to rotate in the same direction by coupling with a predetermined torque due to a frictional load with the sliding cylinder 36. However, as shown in FIG. 9, while the hook 35c is locked by the pawl lever 7, the cam unit 35 slips and stops.

The sector gear 35 of the cam unit 35
As shown in FIG. 9, d is arranged at a position where it can be engaged with the pinion portion 4a of the drive gear 4. When the hook portion 35c is locked by the claw lever 7, the portion without teeth is the pinion portion. Since it is in the non-meshing position corresponding to 4a, it is not rotated by the pinion portion 4a of the drive gear. Then, when the solenoid 14 is energized and the hook portion 35c is unlocked by the pawl lever 7, the cam unit 35 is rotated by a predetermined torque by the friction load of the torque limiter mechanism (see FIG. 9). (In the direction indicated by the arrow in the figure), the toothed portion of the sector gear portion 35d meshes with the pinion portion 4a of the drive gear, and makes one rotation reliably due to the friction load of the torque limiter mechanism and the rotational force of the drive gear. Then, when the toothless portion of the sector gear portion 35d comes to a position corresponding to the pinion portion 4a, the hook portion 35c is stopped again by being locked by the pawl lever 7.

One sheet of paper is fed by the paper feed roller 1 by one rotation of the cam unit 35, as in the case of the above-described conventional paper feed mechanism. According to this embodiment, the cam unit 35 is provided with the sector gear portion 35d, but is not strongly urged by the torsion spring as in the cam unit of the conventional paper feeding mechanism described above, and the hook portion 35c is not provided. When the locking by the pawl lever 7 is released, there is no possibility that a large collision sound is generated due to rapid rotation and collision with the teeth of the pinion portion 4a of the drive gear.

The disengagement of the pawl lever 7 can be eliminated by providing a torque limiter mechanism. During actual driving for paper feeding, the cam unit 35 is rotated by a sector gear unit 35d integral with the cam unit 35, so that slippage or the like occurs. Also does not occur. Further, the load torque of the torque limiter mechanism can be suppressed low. Since the load torque may be equal to or more than the contact load between the projections 10a of the tray bottom plate 10 and the projections 12a of the friction pads 12 shown in FIG.
-About cm is sufficient.

Next, an example of an image forming apparatus provided with a sheet feeding mechanism according to the present invention will be described with reference to FIG. The image forming apparatus shown in FIG. 10 has a document tray 40 and a paper feed tray 48 mounted on the main body 30 of the apparatus.
A document reading unit that conveys the documents placed on the sheet 0 one by one and reads the image, and an image that sequentially forms an image on the sheets stacked on the paper feed tray 40 based on the image data of the read document. And a forming part.

The original reading section includes a pickup roller 41, a separation tab 42, a feed roller 43, a feed-in roller 44, and a pickup roller 41 for sending out the original one by one.
And feed-out roller 45 and C for reading the image
And a CD unit 46. The image forming unit removes the paper stacked on the paper feed tray 48 by the paper feed roller 1, tray bottom plate 10, bottom plate spring 11, friction pad 12, cam unit (not shown), and the like.
A sheet feeding mechanism for feeding sheets one by one according to any one of the embodiments of the present invention is configured. Further, a process unit 50 including a laser unit 47 and a photosensitive drum 49 for performing electrophotographic processes such as charging, exposure, development, and transfer, a transfer roller 51, a heating roller 53 constituting a fixing unit, and a pressure unit A roller 52 and two sets of paper discharge rollers 54 are provided.

The image data read by the CCD unit 46 is stored by an image processing unit (not shown) and subjected to various processes and corrections. A laser beam modulated in accordance with the image data is transmitted from the laser unit 47 to the process unit 50. And irradiates the photosensitive drum 49 for scanning. Thereby, in the process unit 50, an electrostatic latent image is formed on the surface of the photosensitive drum 49, developed with toner, and fed between the photosensitive drum 49 and the transfer roller 51 by the feed roller 1. On paper (transfer paper)
The toner image is transferred. Then, the sheet on which the toner image has been transferred is fixed by passing between the heating roller 53 and the pressure roller 52 constituting the fixing unit, and the two sets of the discharge rollers 5
4 discharges the paper to the paper discharge unit. The image forming apparatus having the paper feeding mechanism is not limited to such a copying machine, and can be applied to a facsimile, a printer, and the like without any trouble.

Next, a modification of each embodiment of the paper feeding mechanism according to the present invention will be described with reference to FIGS. First, the configuration of the paper feed mechanism of this modified example will be described with reference to FIGS. FIG. 11 is a longitudinal sectional view showing a main part of the paper feed mechanism of this modification, FIG. 12 is an exploded perspective view showing a main part of the paper feed mechanism, and FIG. 13 is a portion showing a positional relationship between the cam and the projection. It is sectional drawing. This modification is different from the first embodiment in that an inclined member 66 is provided in place of the friction pad 12, the configuration of a sheet feeding tray (sheet feeding cassette), and the configuration of the inclined member 6.
Since the positional relationship between the sheet feed roller 6 and the tray bottom plate 10 (sheet feed cassette 71) with respect to the sheet feed roller 1 is different from the case of each embodiment, the description other than these points will be omitted. In addition, the illustration mainly focuses on the configuration and operation of the inclined member,
Although the cam unit, the torque limiter mechanism, and the like described in the first to third embodiments are not shown except for a part, the paper feed mechanism of this modification naturally has any of those configurations. I have.

In this modification, a paper feed cassette 71 is removably mounted on an apparatus body 70 of a shallow housing having a low wall surface on all four sides through an opening on a side surface. A tray bottom plate 10 capable of stacking a plurality of sheets 62 shown in FIG. 11 is swingably supported at one end by a support shaft 10 b in the cassette 71. The free end is constantly urged upward in FIG. 11 by the spring 11. In the device body 70,
The sheets 62 stacked on the tray bottom plate 10 having a biasing force in the counterclockwise direction in FIG.
The paper feed roller 1 is provided so as to be able to press against the leading end of the uppermost sheet 62a of the sheet. The contact surface 66b of the inclined member 66 having the inclined surface 66a is Are pressed by the urging force, and these constitute a separating portion for the sheet.

As shown in FIG. 12, the inclined member 66 is provided with ribs 66d, 66d projecting from both left and right side surfaces, slidably guided by guide rails 68, 68 on the apparatus body 70 side. A transport roller that is mounted so as to be able to move in parallel in a direction in which the paper 62 is pressed against, and transports the paper 62 fed by a paper feed roller to an image forming unit of an image forming apparatus (not shown) downstream of the inclined member 66. A pair 67 is supported rotatably. The parallel moving means of the inclined member 66 may be provided by providing a guide rail on the inclined member 66 side and a rib on the apparatus main body 70 side.

Although not shown in FIG. 11,
The tray bottom plate 10 indicated by the imaginary line in FIG. 12 is fixed to the front end and extends upward, as also indicated by the imaginary line.
It is bent outward at a right angle and further pushed forward by the pressed portion 10c _1.
Is provided. The tilt member 66 is also provided with a protrusion 66e that extends the pressed portion 66e ₁ with bent folded at right angles to the further upward extending laterally from its rear. Further, a pair of hook portions 66f, 66f for retaining are extended below the inclined member 66, and engage with a not-shown locking portion on the apparatus main body 70 side to limit the ascending limit. I am trying to.

These projections 10c and 66e are provided in FIG.
, The first cam 1 of the cam unit 15
The pressed portions 10c ₁ , 66e are attached to the 5a and the second cam 15b.
₁ is extended so as to abut. When the cam unit 15 is in the stopped state, the projection 10c is pushed back by the first cam 15a, so that the tray bottom plate 10 retreats downward so that the paper thereon does not contact the paper feed roller 1. When the protrusion 66e is pushed back by the second cam 15b, the inclined member 66 retreats downward and is in a state of not contacting the sheet feeding roller 1. FIG. 13 shows a cross section of only the vicinity of the cam of the cam unit 15 as viewed from the side opposite to the sheet feeding tray.

Here, referring to FIG. 14, tray bottom plate 1
The relationship between the paper 62 stacked on the sheet No. 0, the paper feed roller 1 and the inclined member 66 will be described in more detail. FIG.
FIG. 3 is a cross-sectional view illustrating the positional relationship of each member near a paper feed roller in more detail. The illustration of the hook portion 66f and the like provided below the inclined member 66 is omitted. The inclined surface 66a of the inclined member 66 is set so that the uppermost sheet 62a of the plurality of sheets 62 stacked on the tray bottom plate 10 has a predetermined angle θ with respect to the feeding direction S by the sheet feeding roller 1. . Then, the paper feed roller 1 continuous with the inclined surface 66a
The contact surface 66b is formed as a ridge along the axial direction of the paper feed roller 1, and its width is extremely narrow.

Then, the press-contact portion A of the uppermost sheet 62a on the tray bottom plate 10 which presses against the sheet feeding roller 1 and the inclined surface end 66c where the inclined surface 66a and the contact surface 66b of the inclined member 66 intersect with each other. The distance along the sheet feeding direction with the pressure contact portion B with the roller 1 is set as close as possible,
When a paper feed start signal is issued from a control unit (not shown),
Feed roller 1 until the top sheet 62a has been fed out.
To be able to rotate.

As described above, by reducing the distance between the two press-contact portions A and B, the bending range of the leading end of the paper is narrowed even for various types of paper having different bending elastic coefficients. And the inclined surface 66 of the inclined member 66
The variation of the component force generated in a is also suppressed, and needless to say, in the case of cardboard, postcards, envelopes, etc. having a large flexural modulus,
Paper such as thin paper having a small flexural modulus can be separated, and can be used for various kinds of paper.

Next, the operation of the modified example configured as described above will be described with reference to FIGS. FIG.
Indicates the force relationship of the uppermost sheet 62a. A force F acts on the inclined surface 66a of the inclined member 66 by the leading end of the uppermost sheet 62a as a force for feeding the plurality of stacked sheets 62 to the separation unit by the sheet feeding roller 1. The inclined surface 66a is set at an angle θ with respect to the feeding direction S of the uppermost sheet 62a.
, A component force F1 is generated in a direction perpendicular to and a component force F2 is generated in a direction along the inclined surface 66a.

The separating pressure Q of the tilting member spring 65 for pressing the tilting member 66 against the paper feed roller 1 is set at a predetermined angle α with respect to the feeding direction S of the sheet 62. By setting the component force F1 to be smaller than the α component F1α, the uppermost sheet 62a is fed over the inclined surface 66a of the inclined member 66 in the direction of the transport roller pair 67 shown in FIG.

FIG. 16 shows the force relationship of the next sheet 62b. The next sheet 62c has the next sheet 62c.
A force Fp is exerted by a frictional load between the force Fp and the force Fp. This force Fp generates a component force Fp1 perpendicular to the inclined surface 66a of the inclined member 66 and a component force Fp2 along the inclined surface 66a. However, since the friction coefficient between the papers is generally about 50% of the friction coefficient between the paper feed roller 1 and the papers, the above-mentioned force Fp is also shown in FIG.
The force F is approximately 50% of the force F shown in FIG. 5, and no force is generated over the inclined surface 66a of the inclined member 66. The force F is stopped by the inclined member 66 and separated from the uppermost sheet 62a.

Further, even if the contact surface 66b of the inclined member 66 with the paper feed roller 1 is worn by friction with the sheet and becomes the wear contact surface 66b 'shown by the broken line in FIG. Since only the parallel movement in the direction of the separation pressure Q of the inclined member spring 65 is performed, the separation condition can be maintained without changing the predetermined inclination angle θ (FIG. 14) of the inclined surface 66a.

Further, by reducing the contact surface 66b of the inclined member 66 with the feed roller 1, the uppermost sheet 6
2a is reduced from the conventional nip width D to the nip width C, and the trailing end of the uppermost sheet 62a passes through the nip, and then the paper sheet 6 is rotated by the paper feed roller 1 to rotate the next sheet 6a.
Since the feed amount corresponding to the nip width that gives the feeding force F1 to 2b is also reduced, it is possible to suppress the double feed of the paper 62.

In the sheet feeding device having such a configuration, since the inclined member 66 has a complicated shape, it is preferable to integrally mold the inclined member 66 with a synthetic resin. In that case, FIG.
20, the contact surface 66b of the inclined member 66
If the length A is larger than the length B in the axial direction of the paper feed roller 1, the contact surface 66 of the inclined member 66 that is pressed in the direction of the paper feed roller 1 when the paper (not shown) is conveyed and is in sliding contact with the paper.
As for b, the separation pressure is applied to the central part thereof, so that only the central part of the contact surface 66b pressed by the paper feed roller 1 via the paper is worn and depressed. When the inclined member 66 is deformed in this way, when the sheet enters between the paper feed roller 1 and the inclined member 66, the sheet is fed while being curved following the deformed contact surface 66b of the inclined member 66. . For this reason, the paper transport load becomes extremely large, or the paper cannot be bent with a highly rigid paper, resulting in non-feeding.

Therefore, as shown in FIG.
6 is smaller than the length of the feed roller 1 in the axial direction, so that the total length of the contact surface 66b is
It is good to be able to contact. According to such a configuration, since the contact surface 66b of the inclined member 66 is pressed by the paper feed roller 1 through the entire length of the sheet, a partial depression is formed in the contact surface 66b. There is no fear, the contact surface 66b
Results in linear wear on average. Since the inclined member 66 moves in parallel with the direction of the sheet feeding roller 1, the inclined surface 66a of the inclined member 66 must maintain a predetermined angle with respect to the sheet conveying direction even when the contact surface 66b is worn. Is possible.

FIG. 21 is an exploded perspective view showing a main part of still another modification of the present invention, and FIG. 22 is a sectional view thereof. In this modification, a thin elastic metal plate 69 formed by bending an inclined surface 69a and an abutting surface 69b which engage with an inclined surface 66a and an abutting surface 66b of an inclined member 66, respectively.
Is inserted from the inclined surface 66a side of the inclined member 66. Thus, the elastic metal plate 69 is expanded from the state shown by the imaginary line in FIG. 22 against its elastic force and then contracted and fixed as shown by the solid line.

In this embodiment, the inclined surface 6 of the inclined member 66
6a and the surface of the contact surface 66b are tightly covered with the elastic metal plate 69, so that
a is maintained at a predetermined angle θ, the wear of the inclined member 66 due to friction with the sheet plate can be significantly reduced. In the above embodiment, the inclined surface 66a is also covered at the same time because of the elasticity of the elastic metal plate 69, but this is not always necessary. Further, in the case of this modification, since the wear itself of the inclined member 66 is suppressed, the length of the contact surface 66b is free, and can be determined irrespective of the length of the sheet feeding roller 1 in the axial direction.

It should be noted that from the results of repeated experiments, the paper 62
As shown in FIG. 18, the conditions for performing good separation of the paper 6 are as follows.
2 and the inclined member 6 pressing against the paper feed roller 1
6 in the sheet feeding direction with respect to the press-contact portion B of No. 6 is 2 to 6
mm, and the angle θ formed by the inclined surface 66a of the inclined member 66 with respect to the feeding direction S of the fed sheet 62 is 50 °.
It turned out that it is good to set it to ~ 70 °. In this case, the size of the paper feed roller 1 is usually used, for example, φ1
It has been confirmed that good separation quality can always be obtained as long as it is within the range of 6 to 36 mm.

Next, an image forming apparatus provided with the paper feed mechanism of this modification will be described with reference to FIG. FIG.
FIG. 2 is a configuration diagram of a copying machine that is an example of the image forming apparatus.
In the copying machine 80, an optical writing system 83 forms a latent image on a photoreceptor 85 provided in an image forming system 84 based on image data read by an optical reading system 82 provided in a copying machine main body 81. Then, the developing device 86 of the image forming system 84 converts the latent image into a visible image using toner. A sheet feeding device P having the above-described sheet feeding mechanism is provided at a lower portion of the copying machine main body 81. The sheets 62 stacked from the sheet feeding device P are fed one by one by the sheet feeding roller 1 and conveyed. The visible image on the photoconductor 85 is transferred onto the paper 62 by the roller pair 67 and conveyed to the image forming system 84 through the conveyance path 87.

When the transfer is completed, the sheet 62 is conveyed to a fixing device 88 where a visible image is fixed, and then discharged to an external discharge tray 90 by a pair of discharge rollers 89. Further, at the time of double-sided image formation, the sheet 62 is conveyed from the reversing conveyance path 91 to the double-sided device 92 by a discharge branching claw (not shown), and once stored in the double-sided tray 93, the traveling direction is reversed.
The sheet is again fed from the double-sided conveyance path 94 to the image forming system 84 to form an image on the back surface, and passes through the fixing device 88 to the discharge tray 9.
Drained above zero. Although only one sheet feeding device P is shown in FIG. 23 for simplification of the drawing, a plurality of sheet feeding devices having different sizes can be provided as needed. Further, the image forming apparatus having this paper feeding mechanism is not limited to a copying machine, and can be applied to a facsimile, a printer, and the like without any trouble.

[0064]

As described above, the paper feeding mechanism according to the present invention does not generate a gear collision noise during paper feeding. In addition, the inconvenience that the hook portion of the cam unit is inadvertently disengaged from the claw lever and the sheet feeding is started immediately at the time of subsequent startup does not occur. Therefore, cost reduction and space saving of the sheet feeding mechanism can be realized without inconvenience. In addition, instead of the friction pad, an inclined member having an inclined surface with which the front end in the paper feeding direction abuts, and an abutting surface with the paper feed roller provided with a ridge formed along a protruding line along the axial direction of the paper supply roller is provided. Even when the leading edge of the paper is in a state where it can be a transport load at the time of paper feeding, since there is no friction member, the paper is not caught by the separation unit, and the possibility of occurrence of non-feed is eliminated. Further, even if the coefficient of friction between the stacked sheets has a large variation, the next sheet does not climb over the inclined member due to the frictional force of the preceding sheet, so that double feeding does not occur, and the sheet feeding and conveyance is not performed. Quality can be improved. The image forming apparatus according to the present invention can also realize a small and inexpensive apparatus without causing a problem in the paper feeding mechanism.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a member attached to a paper feed roller shaft in a paper feed mechanism according to a first embodiment of the present invention.

FIG. 2 is a sectional view along the axial direction in the assembled state.

FIG. 3 is a view for explaining a drive mechanism of the cam unit.

FIG. 4 is an explanatory view similarly viewed from the opposite side.

FIG. 5 is an exploded perspective view of a member attached to a paper feed roller shaft in a paper feed mechanism according to a second embodiment of the present invention.

FIG. 6 is a sectional view along the axial direction in the assembled state.

FIG. 7 is an exploded perspective view of a member attached to a paper feed roller shaft in a paper feed mechanism according to a third embodiment of the present invention.

FIG. 8 is a sectional view along the axial direction in the assembled state.

FIG. 9 is a view for explaining a drive mechanism of the cam unit.

FIG. 10 is a diagram showing a schematic configuration of a mechanism section of a small-sized copying machine having a paper feeding mechanism according to the present invention.

FIG. 11 is a longitudinal sectional view showing a main part of a modified example of the sheet feeding mechanism of each embodiment of the present invention.

FIG. 12 is an exploded perspective view showing a main part of the paper feeding mechanism.

FIG. 13 is a partial cross-sectional view showing the positional relationship between the cam and the projection.

FIG. 14 is a cross-sectional view showing the positional relationship of each member near a paper feed roller of the paper feed mechanism shown in FIG. 11 in more detail.

FIG. 15 is an explanatory diagram showing a force relationship of the uppermost sheet.

FIG. 16 is an explanatory diagram showing the force relationship of the next sheet.

FIG. 17 is an explanatory view showing a worn state of the inclined member.

FIG. 18 is an explanatory view showing the relationship between the sheet feeding roller and the inclined member.

FIG. 19 is an exploded perspective view showing the length relationship between the sheet feeding roller and the inclined member.

FIG. 20 is a longitudinal sectional view of the same.

FIG. 21 is an exploded perspective view corresponding to FIG. 12, showing a main part of still another modified example of the paper feeding mechanism.

FIG. 22 is a cross-sectional view showing a mounted state of the inclined member and the elastic metal plate.

FIG. 23 is a configuration diagram illustrating an example of an image forming apparatus including a sheet feeding mechanism according to a modified example of each embodiment of the present invention.

FIG. 24 is a perspective view of an essential part showing an example of a conventional paper feed mechanism to which the present invention is applied in an image forming apparatus.

FIG. 25 is a view for explaining a drive mechanism of the cam unit.

[Explanation of symbols]

 1: paper feed roller 2: paper feed roller shaft 3: passive gear 4: drive gear 10: tray bottom plate 11: bottom plate spring 12: friction pad 13: friction pad spring 14: solenoid 15, 25, 35: cam unit 15a, 25a , 35a: first cam 15b, 25b, 35b: second cam 15c, 25c, 35c: hook portion 15d: spring storage chamber 15e: locking groove 17: coil spring 26, 36: sliding cylinder 26a, 36a: sliding Plate portions 27, 37: compression spring 35d: sector gear portion 35e: storage chamber 62: paper 65: inclined member spring 66: inclined member 66a: inclined surface 66b: contact surface 66d: rib 68: guide rail 69: elastic metal plate

[Procedure amendment]

[Submission date] August 1, 2001 (2001.8.1)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

FIG. 5

FIG. 6

FIG. 7

FIG.

FIG. 8

FIG. 9

FIG. 10

FIG. 11

FIG.

FIG. 13

FIG.

FIG. 14

FIG. 15

FIG. 16

FIG.

FIG. 24

FIG. 25

FIG.

FIG. 21

FIG.

FIG. 23

Claims (13)

[Claims] A feed roller, a feed roller shaft to which the feed roller is fixed, a cam unit rotatably supported by the feed roller shaft, and a pawl lever for stopping the rotation of the cam unit. A solenoid for rotating the pawl lever in a direction away from the hook portion of the cam unit, and a passive gear for rotating the paper feed roller shaft;
A drive gear for rotating the passive gear, wherein when the solenoid operates to release the pawl lever from the cam unit and the cam unit makes one rotation in the same direction as the paper feed roller shaft, The paper is allowed to contact the paper feed roller by the tray bottom plate, and the friction pad is allowed to contact the paper feed roller.
In a sheet feeding mechanism configured to feed sheets, a torque limiter mechanism that connects the cam unit and the sheet feeding roller shaft with a predetermined torque is provided between the cam unit and the sheet feeding roller shaft. A paper feed mechanism, characterized in that: 2. A paper feed roller, a paper feed roller shaft to which the paper feed roller is fixed, a cam unit rotatably supported by the paper feed roller shaft, and a claw lever for stopping rotation of the cam unit. A solenoid for rotating the pawl lever in a direction away from the hook portion of the cam unit, and a passive gear for rotating the paper feed roller shaft;
A drive gear for rotating the passive gear, wherein the actuation of the solenoid causes the pawl lever to be disengaged from the cam unit, and the cam unit rotates once in the same direction as the paper feed roller shaft. A sheet feeding mechanism configured to feed one sheet of paper by allowing the tray bottom plate to contact the sheet with the sheet feeding roller and allowing the inclined member to contact the sheet feeding roller. The inclined member has an inclined surface with which a front end in the feeding direction of the sheet abuts, and a contact surface with the paper feed roller is formed in a ridge along an axial direction of the paper feed roller. A paper feed mechanism, wherein a torque limiter mechanism for connecting the cam unit and the paper feed roller shaft with a predetermined torque is provided between the paper feed roller shaft. 3. The paper feed mechanism according to claim 2, wherein the inclined member has a parallel moving unit that moves the inclined member forward and backward in parallel with the paper feed roller. 4. The paper feed mechanism according to claim 2, wherein a length of a contact surface of the inclined member with the paper feed roller is smaller than a length of the paper feed roller in an axial direction. And paper feed mechanism. 5. The sheet feeding mechanism according to claim 2, wherein the inclined member is formed of a synthetic resin, and at least a contact surface with the sheet feeding roller is formed of an elastic metal plate. A paper feed mechanism characterized by being covered. 6. The sheet feeding mechanism according to claim 2, wherein the sheets stacked on the inclined member and the tray bottom plate respectively contact or contact the sheet feeding roller. A paper feed mechanism, wherein the distance between the portions along the paper transport direction is 2 mm to 6 mm, and the angle of the inclined surface of the inclined member with respect to the paper transport direction is set at 50 ° to 70 °. 7. The paper feed mechanism according to claim 1, wherein the torque limiter mechanism is inserted into the paper feed roller shaft, and between the torque limiter mechanism and an outer peripheral surface of the paper feed roller shaft. A paper feed mechanism comprising a coil spring that generates frictional force and has one end locked to the cam unit. 8. The paper feed mechanism according to claim 7, wherein a spring storage chamber for storing the coil spring is provided in the cam unit. 9. The paper feed mechanism according to claim 1, wherein at least a region of the outer peripheral surface of the paper feed roller shaft that slides with the coil spring is hardened by induction hardening. And paper feed mechanism. 10. The paper feeding mechanism according to claim 8, wherein grease is applied to at least a region of said paper feeding roller shaft which slides with said coil spring, and at least a part of said spring storage chamber is filled with grease. A paper feed mechanism characterized in that: 11. The paper feed mechanism according to claim 1, wherein the torque limiter mechanism is inserted into the paper feed roller shaft and slides on an end face of the cam unit. And a compression spring for pressing the sliding member against an end surface of the cam unit, wherein the predetermined torque is generated by a frictional load between the cam unit and the sliding member. . 12. The paper feeding mechanism according to claim 1, wherein the cam unit is provided with a sector gear that can mesh with the drive gear, and the rotation of the cam unit is controlled by the pawl. The sheet feeding mechanism according to claim 1, wherein the sector gear portion has a toothless portion at a non-meshing position corresponding to the drive gear when stopped by a lever. 13. An image, comprising: the sheet feeding mechanism according to claim 1; and an image forming unit that forms an image on a sheet fed by the sheet feeding mechanism. Forming equipment.