JP3673612B2 - Sheet feeding apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet feeding device of an image forming apparatus such as a printer, and includes, for example, a so-called multi-feed tray that has a back surface that also serves as an exterior and can be opened and closed with respect to the main body of the device. The present invention relates to a technique suitable for a sheet feeding device of an image forming apparatus that separates and feeds sheets one by one by opposing friction members.
[0002]
[Prior art]
Conventionally, in order to reduce the size of the sheet feeding apparatus of this type, as shown in FIG. 15A, a sheet loading tray 101 whose rear surface also serves as an exterior cover is provided near the exterior 102 of the apparatus main body. The support shaft 103 is provided so as to be openable toward the outside of the apparatus main body, and a feeding roller 104 is provided in the vicinity of the exterior 102 of the apparatus main body.
[0003]
Therefore, the middle plate 105 that supports the leading end of the sheet S stacked on the sheet loading tray 101 and is pressed against the feeding roller 104 with a predetermined pressure by an urging means (not shown) Since the center 106 is disposed between the feeding roller 104 and the exterior 102, the length of the intermediate plate 105 in the sheet feeding direction (distance from the feeding roller 104 to the swing center 106 of the intermediate plate 105) L Is set to a very short length of about 40 mm to 100 mm, for example.
[0004]
Then, when the sheets S are stacked on the sheet loading tray 101 at an appropriate height h and the sheets S are pushed in the direction of the feeding roller 104, as shown in FIG. Optimal angle (angle formed by the surface of the separation pad 108 and the surface of the intermediate plate 105) θ ₁ When the leading edge of the sheet S on the intermediate plate 105 is guided to the nip portion between the feeding roller 104 and the separation pad 108 and the feeding roller 104 is rotated in the direction of arrow a in FIG. As shown in (b), the leading edge of the sheet S is rolled by the separation pad 108 urged by the coil spring 107 on the downstream side of the intermediate plate 105 and pressed against the feeding roller 104, and the sheet S is normally separated. Only the top one is separated and fed.
[0005]
[Problems to be solved by the invention]
In the above configuration, it is desirable that the contact angle of the sheet S stacked on the intermediate plate 105 with respect to the feeding roller 104 is kept constant regardless of the stacking height h of the sheet S. However, in the above-described conventional technology, the length L of the intermediate plate 105 in the sheet feeding direction is set to a very short length, so that when the sheet S is designed optimally when a small amount of sheets S are stacked, When fully loaded, the leading edge of the sheet S enters the nip portion between the feeding roller 104 and the separation pad 108 while being inclined downward by the angle α shown in FIG.
[0006]
Here, as shown in FIG. 16A, the height h of the sheets S stacked on the sheet loading tray 101 is relatively low, and the inclination angle θ of the intermediate plate 105 ₂ If it is too small, the separation operation of the sheet S by the separation pad 108 is not performed effectively, and so-called double feeding in which a plurality of sheets S pass between the feeding roller 104 and the separation pad 108 may occur. is there.
[0007]
Further, as shown in FIG. 16B, the height h of the sheets S stacked on the sheet loading tray 101 is relatively high, and the inclination angle θ of the intermediate plate 105 _Three Is too large, the leading edge of the sheet S cannot normally enter the nip portion between the feeding roller 104 and the separation pad 108, and the leading edge of the sheet S may be broken to cause a feeding failure and jam. .
[0008]
In order to avoid the above problem, the stacking height h of the sheet S is set to a small value in the specification so that the angle α is not restricted to be used in a small range, and a user who wants to use it with a large capacity can be used. However, there is a problem that the number of replenishment of the sheet S increases and the office work efficiency is lowered.
[0009]
SUMMARY OF THE INVENTION The present invention solves the above-described problems, and an object of the present invention is to enable a large-capacity stacking and feeding of a sheet even in a multi-feed tray-type sheet feeding device designed to be compact. It is an object of the present invention to provide a sheet feeding apparatus and an image forming apparatus including the sheet feeding apparatus.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a representative configuration according to the present invention includes an arm that can be opened and closed toward the outside of the apparatus body around an opening and closing fulcrum provided in the vicinity of the exterior of the apparatus body, and the apparatus of the arm. A sheet mounting means configured to be swingable with respect to the sheet feeding means about a swing center provided on the opposite side of the opening / closing fulcrum with respect to the main body, and a sheet placed on the sheet mounting means. A sheet feeding means for feeding, a control member rotating with the rotation of the sheet feeding means, and abutting or separating from the control member with the rotation of the control member; A cam follower that is stopped and integrated, and an urging means that abuts on the opposite side of the control member of the cam follower and urges the sheet placing means against the sheet feeding means via the cam follower; The control When the material comes into contact with the cam follower, the sheet placed on the sheet placing means is separated from the sheet feeding means against the urging force of the urging means, and the control member is separated from the cam follower. Thus, the sheet feeding device is characterized in that the sheet placed on the sheet placing means is brought into contact with the sheet feeding means by the urging force of the urging means.
[0011]
Since the present invention is configured as described above, the center of swinging of the sheet placing unit with respect to the sheet feeding unit is set at a position sufficiently separated from the sheet feeding unit in the sheet conveying direction. It is possible to suppress a change in the angle of the sheet placing means from when the sheet is fully loaded to when the sheet is loaded in a small amount, thereby maintaining good sheet separation and feeding performance regardless of the sheet stacking height. Therefore, even a multi-feed tray type sheet feeding apparatus designed to be compact in size can make it possible to load and feed a large amount of sheets. Further, the control member is brought into contact with the cam follower to separate the sheet placed on the sheet placing means against the urging force of the urging means from the sheet feeding means, and the control member is By separating from the cam follower, the sheet placed on the sheet placing unit is brought into contact with the sheet feeding unit by the urging force of the urging unit. Thereby, favorable sheet conveyance can be performed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a sheet feeding apparatus according to the present invention and an image forming apparatus including the same will be described in detail with reference to the drawings. FIG. 1 is a conceptual diagram of a sheet feeding apparatus according to the present invention, FIG. 2 is a perspective view showing the configuration of the first embodiment of the sheet feeding apparatus according to the present invention, and FIG. 3 also serves as an exterior cover of the first embodiment. FIG. 4 is a perspective view showing the configuration of the arm fixing means of the first embodiment, and FIG. 5 also serves as the exterior cover of the first embodiment. FIG. 6 and FIG. 7 are cross-sectional explanatory views showing the operation of the control member of the first embodiment, and FIG. 8 and FIG. 9 are the first embodiment. FIG. 10 is a cross-sectional explanatory view showing the releasing operation of the fixing means that fixes the sheet placing means that also serves as the exterior cover in the open state, and FIG. It is.
[0013]
FIG. 1 is a conceptual diagram of a sheet feeding apparatus according to the present invention. In the vicinity of the free end side of the sheet loading tray 1 serving as a sheet loading means that also serves as an exterior cover, a swing center that swings with respect to the feeding roller 2 serving as the sheet feeding means of the sheet loading tray 1 is provided. By providing the swing shaft 3, the separation distance L from the feed roller 2 to the swing shaft 3 of the sheet stacking tray 1 in the sheet conveying direction is sufficiently long, and the leading end of the sheet S is connected to the feed roller 2. The downward inclination angle α when entering the nip portion with the separation pad 4 serving as the friction separation means can be kept small.
[0014]
With the above configuration, it is possible to maintain good sheet separation and feeding performance regardless of the stacking height h of the sheets S. Therefore, even with a multi-feed tray type sheet feeding device designed to be compact, it is possible to load and feed a large volume of sheets S in the same manner as a large-capacity cassette incorporated in the device.
[0015]
A first embodiment in which the sheet feeding device is embodied will be described in detail with reference to FIGS. In FIG. 2, reference numeral 5 denotes an exterior of the apparatus main body, and a sheet placing tray 1 serving as a sheet placing means serving as an exterior cover as a part of the exterior 5 serves as an opening / closing fulcrum provided in the vicinity of the exterior 5 of the apparatus main body. It is configured to be openable and closable integrally with the arm 13 around the support shaft 6 toward the outside of the apparatus main body.
[0016]
A feeding roller 2 provided relatively close to the support shaft 6 and serving as a sheet feeding means for feeding a sheet S made of paper, synthetic resin or the like placed on the sheet placing tray 1 is rotated. It is fixed to a feed shaft 10 to which rotational driving force is transmitted via gears 7 and 8 and a one-turn control clutch 9 connected to a motor M serving as a drive source, and makes one rotation by the action of the one-turn control clutch 9. Be controlled.
[0017]
A cam 11 serving as a control member is fixed to the feeding shaft 10, and the cam 11 is also controlled to make one rotation integrally with the feeding shaft 10. The phase of the cam 11 is managed so as to always stop at a predetermined position by a sensor (not shown).
[0018]
A separation pad 4 is provided opposite to the feed roller 2 as a friction separation means that is constantly biased at a predetermined pressure by a biasing means such as a coil spring 12. A nip portion between the feed roller 2 and the separation pad 4 is provided. When the sheet S entering the sheet is fed by the feeding roller 2, the leading edge of the sheet S is rolled by the frictional separation action of the separation pad 4 and separated and fed one by one.
[0019]
The sheet loading tray 1 is a rocking center which is a rocking center provided on each side of the pair of side pieces 13a and 13b on both sides of the U-shaped arm 13 on both sides of the sheet loading tray 1. The arm 13 is swingably attached to the arm 13 around the moving shaft 3, and the arm 13 is rotatable about a support shaft 6 that is an opening / closing fulcrum provided near the exterior 5 of the apparatus main body. It is configured.
[0020]
A recess 1 a is formed at a position corresponding to the bottom piece 13 c of the arm 13 at the end of the sheet stacking tray 1 on the feeding roller 2 side, and the sheet stacking tray 1 is centered around the swing shaft 3. 2 is rotated counterclockwise in FIG. 2, the front surface 1b of the recess 1a and the end 13c1 of the bottom piece 13c come into contact with each other so that the sheet stacking tray 1 and the arm 13 are integrally centered on the support shaft 6. Thus, the sheet stacking tray 1 and the arm 13 are integrally raised and can be closed with respect to the apparatus main body by rotating counterclockwise in FIG.
[0021]
A support shaft 6 serving as an opening / closing fulcrum is disposed on one end side of the sheet placing tray 1, and a swing shaft 3 serving as a swing center is disposed on the other end side of the sheet placing tray 1 opposite to the support shaft 6. Has been. With this configuration, the separation distance L from the feeding roller 2 to the swing shaft 3 of the sheet stacking tray 1 in the sheet conveying direction shown in FIG. 1 is configured to be sufficiently long.
[0022]
The sheet loading tray 1 has an upper surface shown in FIG. 2 as a sheet S loading surface, and a lower surface as an exterior surface of the apparatus when the sheet loading tray 1 is closed.
[0023]
A cam follower 14 abuts on the cam 11 fixed to the feeding shaft 10 and is pivotally supported about the support shaft 6 so as to be swingable. A coil spring 22 serving as an urging means whose one end is locked to the frame of the apparatus main body is in contact with the back surface of the cam follower 14. Can be biased at a predetermined pressure. The biasing means can be constituted by a plate spring or various elastic members in addition to the coil spring 22.
[0024]
A hook 15 is pivotally supported by a shaft 16 at the end of the sheet loading tray 1 on the side of the feeding roller 2, and the hook 15 is engaged with a locking portion 17 provided on the cam follower 14. Thus, the swing of the sheet loading tray 1 with respect to the arm 13 is fixed. The hook 15 and the locking portion 17 provided on the cam follower 14 constitute fixing means for fixing the sheet loading tray 1 in an open state.
[0025]
Further, a handle 19 that is pivotally supported by a shaft 18 is provided on the open end side of the sheet loading tray 1, and the handle 19 is attached to the shaft 18 by a torsion coil spring 20 fitted to the shaft 18. The center is always urged counterclockwise in FIG.
[0026]
The hook 15 and one end of the handle 19 are engaged with each other by a rod 21, so that the hook 15 is always centered around the shaft 16 via the handle 19 and the rod 21 by the elastic force of the torsion coil spring 20. Is urged clockwise.
[0027]
FIG. 2 shows a state in which the sheet loading tray 1 is opened with respect to the apparatus main body, and the hook 15 engages with the recess of the locking portion 17 of the cam follower 14 and the sheet loading tray 1 is locked to the cam follower 14. The cam 11 rotates with the rotation of the feed roller 2 and the sheet loading tray 1 swings around the swing shaft 3 integrally with the cam follower 14 that contacts the cam 11. A state in which the end of the placing tray 1 on the side of the feeding roller 2 moves up and down with respect to the feeding roller 2 is shown.
[0028]
3, the user pushes up the handle 19 in the direction of the arrow c to release the engagement of the hook 15 with the locking portion 17 of the cam follower 14 as shown in FIG. 2, the front surface 1 b of the recess 1 a of the sheet stacking tray 1 abuts against the end 13 c 1 of the bottom piece 13 c of the arm 13, so that the sheet stacking tray 1 is connected to the arm 13. 2 shows a state in which the sheet stacking tray 1 is erected by rotating counterclockwise in FIG. 2 around the support shaft 6 and closed with respect to the apparatus main body.
[0029]
When the sheet stacking tray 1 is opened with respect to the apparatus main body, as shown in FIG. 4, the base portion of the side piece 13 a of the arm 13 is provided on the upper surface 5 a of the exterior 5 facing the lower portion of the support shaft 6. The amount of opening of the arm 13 is regulated by contacting the stopper 23, and when the sheet loading tray 1 is fully opened, the hook 15 is provided with a locking portion 17 provided on the cam follower 14, as shown in FIG. Is set to be engaged and locked.
[0030]
FIG. 6 shows a state where the sheet S is set on the sheet loading tray 1 in a state where the sheet loading tray 1 is opened with respect to the apparatus main body. From this state, when the motor M is turned on and the one-turn control clutch 9 operates, as shown in FIG. 7, the cam 11 rotates in the direction of arrow b in FIG. 7, and the cam 11 contacts and slides on the cam follower 14. While moving from the large diameter portion to the small diameter portion, the cam follower 14 is raised by the extension force of the coil spring 22.
[0031]
At this time, with the hook 15 being locked to the locking portion 17 of the cam follower 14, the sheet loading tray 1 swings integrally with the cam follower 14 in the clockwise direction of FIG. Eventually, the cam 11 moves away from the cam follower 14. Then, the uppermost sheet S placed on the sheet placing tray 1 comes into contact with the feeding roller 2 with a predetermined pressure, and the sheet S is fed out by the feeding roller 2 that rotates integrally with the cam 11. The leading edge of the sheet S enters the nip portion between the feeding roller 2 and the separation pad 4, and only the uppermost sheet S is separated and fed.
[0032]
When the cam 11 further rotates in the direction of arrow b in FIG. 7, the cam 11 comes into contact with and abuts the cam follower 14, and the cam 11 moves from the small diameter portion to the large diameter portion while abutting and sliding on the cam follower 14. The cam follower 14 is pressed downward against the extension force of the coil spring 22 by the cam 11, and the sheet loading tray 1 is integrated with the cam follower 14 in a state where the hook 15 is locked to the locking portion 17 of the cam follower 14. Oscillates counterclockwise in FIG.
[0033]
As a result, the sheet S on the sheet loading tray 1 and the feeding roller 2 are separated from each other, and a transition is made to a feeding start standby state for the subsequent sheet S.
[0034]
According to the above configuration, the sheet loading tray 1 swings around the swing shaft 3 that is sufficiently separated from the feeding roller 2, so that the sheet S can be used regardless of whether the sheet S is loaded or small. The contact angle between the surface and the feeding roller 2 hardly changes. Therefore, stable separation and feeding performance of the sheet S can be maintained until the sheet S is full, and the sheet S can be fed satisfactorily while preventing poor feeding or double feeding of the sheet S.
[0035]
Further, in the state in which the sheet loading tray 1 is opened with respect to the apparatus main body so that the sheet S can be loaded, the hook 15 is locked and fixed to the locking portion 17 of the cam follower 14. The loading tray 1 is not inadvertently closed, and the arm 13 in contact with the stopper 23 on the exterior 5 does not move during the sheet S feeding operation, and the sheet S on the sheet loading tray 1 does not move. Corresponding to the remaining amount, the sheet placing tray 1 swings stably around the swing shaft 3.
[0036]
When the sheet tray 1 is closed with respect to the apparatus main body, as shown in FIG. 8, the handle 19 is centered on the shaft 18 in the direction of the arrow c in FIG. The rod 21 is pulled in the direction of the arrow d in FIGS. 8 and 9, and the hook 15 connected to the rod 21 is rotated in the counterclockwise direction in FIG. The sheet stacking tray 1 is released from the locking portion 17 of the cam follower 14 and released, and the sheet stacking tray 1 is pivoted in the direction of arrow e in FIG. The arm 13 and the device main body can be closed together.
[0037]
Next, the configuration of the image forming apparatus equipped with the sheet feeding apparatus according to the present invention will be described with reference to FIG. The right side of the image forming apparatus main body in FIG. 10 is provided with a sheet loading tray 1 that can be opened and closed with respect to the above-described apparatus main body and also serves as an exterior cover. There are provided sheet cassettes K1 and K2 for storing sheets S made of synthetic resin or the like.
[0038]
The sheets S fed from the sheet loading tray 1 by the feeding roller 2 are separated and fed one by one by the separation pad 4 and conveyed to the registration roller pair 24. Further, the sheet S selectively separated and fed from the sheet cassettes K1 and K2 by the sheet separating and feeding means R1 and R2 is conveyed to the registration roller pair 24 by the conveying roller 33 and the like.
[0039]
On the other hand, the surface of the electrophotographic photosensitive drum 25 serving as an image forming unit is uniformly charged by a charging unit (not shown), and laser light including image information is emitted from a laser exposure optical system 26 and reflected by a mirror 27 to be photosensitive. The surface of the body drum 25 is irradiated to form an electrostatic latent image.
[0040]
A toner image is formed on the electrostatic latent image by developing means (not shown), and the sheet S sent by the registration roller pair 24 in synchronization with the rotation of the photosensitive drum 25 is transferred between the photosensitive drum 25 and the transfer roller 28. The toner image on the photosensitive drum 25 is transferred to the sheet S through the nip portion, the toner image is permanently fixed through the fixing device 29, and the image forming apparatus main body is fixed by the conveying roller pair 30 and the discharge roller pair 31. It is discharged onto a discharge tray 32 provided at the top.
[0041]
Next, a second embodiment of the sheet feeding apparatus according to the present invention will be described with reference to FIGS. FIG. 11 is a cross-sectional explanatory view showing a state in which the sheet placing means that also serves as an exterior cover of the second embodiment of the sheet feeding apparatus according to the present invention is opened with respect to the apparatus main body, and FIGS. 12 and 13 show the second embodiment. FIG. 14 is a cross-sectional explanatory view showing the releasing operation of the fixing means that fixes the sheet placing means that also serves as the outer cover in the open state, and FIG. 14 closes the sheet placing means that also serves as the outer cover according to the second embodiment with respect to the apparatus main body. FIG. In addition, what was comprised similarly to the said 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.
[0042]
In this embodiment, a sheet loading tray cover 41 constituting sheet loading means that also serves as an exterior cover is pivotally supported so as to be openable and closable around a pivot 42 that is an opening and closing fulcrum provided in the vicinity of the exterior 5 of the apparatus main body. ing. Further, the open end portion of the sheet stacking tray cover 41 has a hole whose center is the center plate 43 in which the end portion 43a having a Z-shaped cross section is inserted into the hole 41a formed in the sheet stacking tray cover 41. It is supported so as to be swingable around the engaging portion between 41a and the end 43a.
[0043]
A coil spring 44 serving as an urging means for urging the intermediate plate 43 against the supply roller 2 with a predetermined pressure is provided at the end of the sheet loading tray cover 41 on the side of the supply roller 2. With the feeding roller 2 side end in contact with the feeding roller 2, the sheet loading tray cover 41 rotates about the support shaft 42 in the counterclockwise direction of FIG. 11 by the extension force of the coil spring 44. Force acts. The biasing means can be constituted by a plate spring or various elastic members in addition to the coil spring 44.
[0044]
On the other hand, the feeding roller 2 side end of the sheet loading tray cover 41 is locked by a lock hook 46 serving as a fixing means fixed to the inner surface side of the exterior 5 with screws 45, thereby the sheet loading tray. The cover 41 and the intermediate plate 43 are held in an open state with respect to the apparatus main body.
[0045]
In the present embodiment, the lock hook 46 is made of a resin material, and can be bent by its spring property, thereby urging the sheet loading tray cover 41 in the direction of fixing in the open state. The lock hook 46 may be made of other materials as long as it has predetermined elasticity and rigidity.
[0046]
Although not shown, in the present embodiment as well, in the same manner as in the first embodiment, the cam 11 serving as a control member comes into contact with and engages with the intermediate plate 43 and the one-turn control clutch 9 operates in the same manner as described above. / Evacuation operation is performed.
[0047]
Further, as shown in FIG. 12, a handle 48 pivotally supported by a shaft 47 is provided on the open end side of the sheet stacking tray cover 41, and the handle 48 is fitted to the shaft 47. The torsion coil spring 49 is always urged counterclockwise in FIG. 12 around the shaft 47.
[0048]
A compression rod 50 is engaged with the handle 48, and an end portion of the compression rod 50 is disposed at a position facing the lock hook 46. Then, when closing the sheet stacking tray cover 41 integrally with the middle plate 43 with respect to the apparatus main body, the compression rod 50 is pushed up in the direction of the arrow f in FIG. The end of the compression rod 50 pushes the lock hook 46 so that the lock hook 46 is retracted in the direction of the arrow i in FIG. 13, and the lock hook 46 and the sheet loading tray cover 41 are engaged with each other. 14 and the sheet loading tray cover 41 and the intermediate plate 43 integrally rotate about the support shaft 42 in the counterclockwise direction of FIG. 14 and stand up with respect to the apparatus main body as shown in FIG. Closed.
[0049]
11 and FIG. 14 is a locking member provided in the exterior 5 at the top of the sheet loading tray cover 41, and when the sheet loading tray cover 41 is raised and closed with respect to the apparatus main body, The sheet loading tray cover 41 is engaged and locked with a recess 41b formed at the open end of the sheet loading tray cover 41. Other configurations are the same as those in the first embodiment, and the same effects can be obtained.
[0050]
【The invention's effect】
Since the present invention has the above-described configuration and operation, the swing center at which the sheet placing unit swings with respect to the sheet feeding unit is set at a position sufficiently separated from the sheet feeding unit in the sheet conveying direction. As a result, the change in the swing angle of the sheet placement means from when the sheets are fully loaded to when a small amount of sheets are loaded can be kept small, which ensures good sheet separation and feeding performance regardless of the sheet stacking height. Can be maintained. Therefore, even a multi-feed tray type sheet feeding apparatus designed to be compact in size can make it possible to load and feed a large amount of sheets. Further, the control member is brought into contact with the cam follower to separate the sheet placed on the sheet placing means against the urging force of the urging means from the sheet feeding means, and the control member is By separating from the cam follower, the sheet placed on the sheet placing unit is brought into contact with the sheet feeding unit by the urging force of the urging unit. Thereby, favorable sheet conveyance can be performed.
[0051]
Further, due to the action of the fixing means, the swinging center of the sheet placing means vibrates in the closing direction of the sheet placing means due to the feeding pressure received by the sheet placing means from the sheet feeding means during the feeding operation. Problems can also be prevented.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a sheet feeding apparatus according to the present invention.
FIG. 2 is a perspective view illustrating a configuration of a first embodiment of a sheet feeding apparatus according to the present invention.
FIG. 3 is an explanatory cross-sectional view illustrating a state in which the sheet placing unit that also serves as the exterior cover according to the first embodiment is closed with respect to the apparatus main body.
FIG. 4 is a perspective view illustrating a configuration of an arm fixing unit according to the first embodiment.
FIG. 5 is a side view illustrating a configuration of a fixing unit that fixes a sheet placing unit that also serves as an exterior cover according to the first embodiment in an open state;
FIG. 6 is a cross-sectional explanatory view showing the operation of the control member of the first embodiment.
FIG. 7 is a cross-sectional explanatory view showing the operation of the control member of the first embodiment.
FIG. 8 is a cross-sectional explanatory view showing a releasing operation of a fixing unit that fixes the sheet placing unit that also serves as the exterior cover of the first embodiment in an open state;
FIG. 9 is an explanatory cross-sectional view showing the releasing operation of the fixing means for fixing the sheet placing means that also serves as the exterior cover of the first embodiment in an open state.
FIG. 10 is a cross-sectional explanatory diagram illustrating a configuration of an image forming apparatus including a sheet feeding device according to the present invention.
FIG. 11 is an explanatory cross-sectional view illustrating a state in which a sheet placing unit that also serves as an exterior cover of the second embodiment of the sheet feeding apparatus according to the present invention is opened from the apparatus main body.
FIG. 12 is an explanatory cross-sectional view illustrating a releasing operation of a fixing unit that fixes a sheet placing unit that also serves as an exterior cover according to the second embodiment in an open state;
FIG. 13 is an explanatory cross-sectional view illustrating a releasing operation of a fixing unit that fixes a sheet placing unit that also serves as an exterior cover according to the second embodiment in an open state;
FIG. 14 is an explanatory cross-sectional view showing a state in which a sheet placing unit that also serves as an exterior cover according to the second embodiment is closed with respect to the apparatus main body.
FIGS. 15A and 15B are diagrams illustrating a conventional example.
FIGS. 16A and 16B are diagrams for explaining a problem of a conventional example. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sheet loading tray, 1a ... hollow part, 1b ... front surface, 2 ... feeding roller, 3 ... rocking shaft, 4 ... separation pad, 5 ... exterior, 5a ... upper surface, 6 ... support shaft, 7, 8 ... Gear, 9 ... One-turn control clutch, 10 ... Feed shaft, 11 ... Cam, 12 ... Coil spring, 13 ... Arm, 13a, 13b ... Side piece, 13c ... Bottom piece, 13c1 ... End side, 14 ... Cam follower, 15 ... Hook , 16 ... shaft, 17 ... locking portion, 18 ... shaft, 19 ... handle, 20 ... torsion coil spring, 21 ... rod, 22 ... coil spring, 23 ... stopper, 24 ... registration roller pair, 25 ... photoconductor drum, 26 ... Laser exposure optical system, 27 ... mirror, 28 ... transfer roller, 29 ... fixing device, 30 ... conveying roller pair, 31 ... discharge roller pair, 32 ... discharge tray, 33 ... conveying roller, 41 ... sheet placement tray cover, 41a ... Hole, 41b ... Recess, 42 ... Support shaft, 43 ... Medium plate, 43a ... End, 44 ... Coil spring, 45 ... Bis, 46 ... Lock hook, 47 ... Shaft, 4 8 ... handle, 49 ... torsion coil spring, 50 ... compression rod, 51 ... locking member, K1, K2 ... sheet cassette, M ... motor, R1, R2 ... sheet separating and feeding means, S ... sheet

Claims (6)

An arm that can be opened and closed toward the outside of the apparatus body around an opening / closing fulcrum provided in the vicinity of the exterior of the apparatus body;
Sheet placing means configured to be swingable with respect to the sheet feeding means about a swing center provided on the opposite side of the opening / closing fulcrum of the arm with respect to the apparatus main body;
Sheet feeding means for feeding a sheet placed on the sheet placing means;
A control member that rotates in accordance with the rotation of the sheet feeding means;
A cam follower that comes into contact with or separates from the control member as the control member rotates and is integrated with the sheet placing means;
A biasing means that abuts on the opposite side of the control member of the cam follower and biases the sheet placing means against the sheet feeding means via the cam follower;
The sheet placed on the sheet placing means is separated from the sheet feeding means against the biasing force of the biasing means by the control member coming into contact with the cam follower,
The sheet feeding device according to claim 1, wherein the sheet placed on the sheet placing unit is brought into contact with the sheet feeding unit by the biasing force of the biasing unit by separating the control member from the cam follower. A hook that is swingably disposed on a shaft of a side end portion of the sheet placing means and is locked to the cam follower;
A rod that engages with the hook and swings the hook about the shaft;
A handle that pulls the rod to unlock the hook from the cam follower;
The sheet feeding apparatus according to claim 1, further comprising: A sheet placing means that can be opened and closed toward the outside of the apparatus body around an opening and closing fulcrum provided in the vicinity of the exterior of the apparatus body;
An intermediate plate that is swingable with respect to the sheet feeding means and has a sheet placed thereon about a swing center provided on the opposite side of the opening / closing fulcrum of the sheet placing means with respect to the apparatus main body;
Sheet feeding means for feeding a sheet placed on the intermediate plate;
A lock hook for locking and holding the sheet feeding means side end of the sheet placing means when the sheet placing means is opened toward the outside of the apparatus main body;
A biasing means disposed between the sheet feeding means side end of the sheet placing means and the middle plate, and biasing the middle plate against the sheet feeding means;
A sheet feeding apparatus comprising: A compression rod arranged to extend from the rocking center side of the intermediate plate to the lock hook;
A handle that presses the compression rod against the lock hook to release the engagement between the lock hook and the sheet placing means;
The sheet feeding apparatus according to claim 3, further comprising:   The sheet feeding apparatus according to claim 1, wherein the sheet placing unit includes an exterior cover of the apparatus.   A sheet feeding device according to claim 1, comprising image forming means for forming an image on a sheet fed by the sheet feeding device in accordance with image information. Image forming apparatus.

Images