JPH0834529A - Automatic paper feed unit and image forming device - Google Patents

Abstract

PURPOSE:To provide an automatic paper feed unit removably fitted to an image forming device main body, preventing the breakage of gears due to erroneous fitting/removing actions, and capable of stably transmitting the drive. CONSTITUTION:This automatic paper feed unit 50 is provided with a loading base 52 rotatable in the direction F, and it can be set to the using position in the nearly horizontal attitude allowing paper feed and the storage position in the nearly vertical attitude prohibiting paper feed. The unit 50 is provided with the following lock mechanisms for blocking its erroneous fitting or removal during a paper feed action. A unit main body 51 is provided with a lock lever 61 rotatably in the direction G to be set to the position for coupling with the coupling hole 62 of a device main body M and the position retreated from it. The loading base 52 is provided with an arm 64 contactably with the lock lever 61, it is moved to the position (shown by solid lines) allowing the coupling when the loading base 52 is located at the using position, and it is moved to the position releasing the coupling when the loading base 52 is located at the storage position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic paper feeding unit which is detachably attached to the main body of an image forming apparatus such as a printer, a copying machine, a facsimile machine or the like so as to be able to feed the inside thereof.
Also, the present invention relates to an image forming apparatus provided with such an automatic paper feeding unit.

[0002]

2. Description of the Related Art FIG. 7 is an overall view showing an example of a conventional image forming apparatus (here, a printer is shown as an example), and FIG. 8 is an external perspective view thereof. In this image forming apparatus, as shown in FIG.
On the other hand, from the front side of the apparatus (the left side in the figure), a paper feed cassette 1 as a paper storage means that is removable, a paper feed roller 2 as a paper feed means for sequentially feeding the stacked paper sheets, and a paper feed roller 2 A pair of slip rollers 3 that inherits and conveys the conveyed sheet, a pair of standby rollers 4 that temporarily conveys the sheet conveyed by the slip roller pair 3 and then conveys the sheet again at a predetermined timing, and an image on the conveyed sheet. An image forming unit 5 (photosensitive drum 5a, charging device 5b, optical writing head 5c, developing device 5d, transfer device 5e, cleaner 5f, etc.) which forms a toner image based on information, and fixing for fixing the toner image on a sheet. A container 6, a paper discharge roller pair 7 for discharging the fixed paper to the outside of the apparatus, a paper discharge tray 8 for storing the discharged paper, and the like are provided.

In such an apparatus, as shown in FIG. 7, in general, a sheet introduction port 9 for performing manual sheet feeding, which is manual sheet feeding, is provided separately from the sheet feeding from the sheet feeding cassette 1. The sheet is provided on a predetermined side portion of M (on the front side of the apparatus in the figure), and the sheet is manually introduced into the apparatus main body from the sheet introduction port 9 one by one, so that the sheet is directed toward the image forming section 5. Can be delivered. When such a sheet introducing port 9 is provided, an opening / closing member 10 which is a cover for opening and closing the opening portion is provided, and the opening / closing member 10 manually introduces the sheet into the apparatus main body through the sheet introducing port 9. In many cases, the manual guide is also used, and the example shown in FIG. 7 is an example of such a manual guide.

The opening / closing member 10 also serving as a manual feed guide is provided with a slidable guide member 15 for restricting and guiding the end face of the paper in accordance with the width of the paper, and is openable / closable in the direction of arrow A with a hinge portion at one end as a fulcrum. However, as the structure of such a hinge portion, as shown in FIGS. 9 and 10, for example, the convex portion 11 provided on the opening / closing member 10 is replaced with the concave portion 12 on one side of the apparatus main body M (in FIG. Only a concave portion is shown), and a structure in which it is rotatably supported is adopted. Moreover, in the example of FIGS. 9 and 10, a part of the peripheral surface of the convex portion 11 is formed as a flat facing surface 11a and the concave portion 12 is formed so that the convex portion 11 and the concave portion 12 can be engaged with and released from each other. Is provided with a guide groove 12a that guides the convex portion 11 in an oblique direction and is removable. With this structure, the opening / closing member 10 can be removed obliquely upward (direction of arrow B) as shown in FIG. It is possible. Further, as shown in FIG. 11, the opening / closing member 10 and the apparatus main body M side are provided with engaging portions 13 and 14 which can be engaged with and released from each other.
As shown in FIG.
The opening / closing member 10 can be locked at a predetermined closed position by lightly pressing it in the direction, and the opening / closing is performed by releasing the engagement of the engaging portions 13 and 14 by pressing the opening / closing member 10 again in the direction of arrow C. It is possible to open the member 10.

The paper inlet 9 has an opening / closing member 10
There is a case where an automatic paper feeding unit can be optionally attached in a state where the automatic paper feeding unit is removed. An example of such an automatic paper feeding unit is shown in FIG. The automatic paper feeding unit 20 shown in the figure has a stacking base 21 having a wide space as a paper stacking unit for stacking a plurality of papers, and a slidable guide that regulates the end face of the paper according to the width of the paper is provided on the stacking base 21. A member 22 is provided, an auxiliary tray 23 for extending the sheet stacking surface is provided on the stacking table 21, and a sheet feeding roller for sequentially feeding the stacked sheets into the apparatus main body. It also has a dedicated motor 25 for driving the paper feed roller 24. Such an automatic paper feeding unit can be fixed to the apparatus main body M with a screw or can be attached and detached with one touch.
Various proposals have been made.

However, the automatic paper feeding unit 20 shown in FIG.
As described above, since the drive source such as the dedicated motor 25 for rotatably driving the paper feed roller 24 and the electromagnetic clutch for performing the drive control are provided as described above, the entire unit is increased in size. In addition, there is a problem that the structure becomes complicated and expensive. Therefore, the applicant of the present application has already commercialized the automatic sheet feeding unit 30 having a compact structure as shown in FIGS.

As shown in FIG. 13, the automatic paper feeding unit 30 includes a loading table 21 for the automatic paper feeding unit 20.
Compared with the above, a stacking table 31 having a considerably smaller space is provided as a sheet stacking section, and the stacking table 31 is attached to the unit main body so as to be rotatable (openable and closable) in the direction of arrow D, so that sheet feeding by the sheet feeding roller 32 is possible. It is possible to take a substantially horizontal posture use position (position shown in FIG. 13) and a substantially vertical posture storage position (position shown in FIG. 14 or FIG. 15) in which feeding is impossible. A guide member 33 that regulates the end surface of the sheet is slidably provided on the upper surface of the stacking table 31, and the end of the stacking table 31 extends the sheet stacking surface to support the sheet as shown in FIG. The auxiliary tray 34 can be attached. This automatic paper feeding unit 30
Includes a paper feed roller 32, but does not include a drive source such as a motor for driving the paper feed roller 32, a complicated structure such as an electromagnetic clutch, and a drive transmission member such as gears 35 to 38 shown in FIG. The rotational driving force from the driving source in the apparatus main body M is transmitted to the sheet feeding roller 32 via the.

As shown in FIG. 14, the automatic sheet feeding unit 30 and the apparatus main body M having such a structure are provided with engaging members 39 and 40 which can be engaged with each other, and the opening / closing member 10 also serving as a manual feed guide. When the automatic sheet feeding unit 30 is attached to the apparatus body M by engaging the engaging members 39 and 40 with (FIG. 11) removed from the apparatus body M, automatic sheet feeding is possible. Further, as shown in FIG. 14, the release lever 41 connected to the engaging member 39 on the side of the automatic paper feeding unit 30 is provided with an arrow E _{1 as} shown in FIG.
By pushing in the E ₂ direction, the engagement between the engaging members 39 and 40 can be released, and the automatic sheet feeding unit 30 can be easily removed from the apparatus main body M.

[0009]

The automatic sheet feeding unit 30 shown in FIG. 13 is the same as the automatic sheet feeding unit 2 shown in FIG.
Compared with 0, it has a compact and inexpensive structure, and can be easily attached to and detached from the apparatus main body M, but has the following problems.

First, since the automatic paper feeding unit 30 is easily attached to and detached from the apparatus main body M, the automatic paper feeding unit 30 is
There is a case where the release lever 41 is erroneously pressed and the engagement members 39 and 40 are disengaged from each other even though the sheet feeding operation is being performed by the automatic feeding from the drive gear on the apparatus main body M side. Gear 35 for drive transmission on the side of the paper unit 30
Since the meshing is disengaged while the driving force is being transmitted to the gears, an abnormal force is applied to each gear and the gears are damaged.

Secondly, as shown in FIG. 14, the automatic paper feeding unit 30 has two sets of engaging portions 39 and 40 with respect to the apparatus main body M.
Although it is a structure that is fixed at 2 points (line fixed),
In such two-point fixing, a force to rotate the entire unit around the fixed point acts at the time of transmission of drive from the drive gear on the apparatus main body M side to the gear 35, and thus rattling occurs in the entire unit. There is also a problem that drive transmission becomes unstable. If the mechanism is simply fixed at three points, the rattling described above can be prevented, but the work of attaching and detaching the automatic sheet feeding unit 30 becomes troublesome, which is not preferable.

Thirdly, since the automatic paper feeding unit 30 does not require a dedicated motor for driving the paper feeding roller 32, the structure of the unit itself is very compact, but conversely, the main body M of the apparatus is , Paper feed roller 2 for cassette paper feed
In addition to a dedicated electromagnetic clutch for controlling the transmission of the driving force to (FIG. 7), the paper feed roller 3 of the automatic paper feed unit 30 is also provided.
It is necessary to further include a dedicated electromagnetic clutch for controlling the transmission of the driving force to the motor 2, that is, two sets of the electromagnetic clutch and its peripheral mechanism are required. Since such an electromagnetic clutch and its peripheral mechanism have a complicated structure and require a large space, there is a problem in that the size and cost of the entire apparatus are increased.

In view of the above problems, the present invention can prevent damage to gears and the like due to an erroneous attachment / detachment operation without impairing operability at the time of attachment / detachment, and also enables stable drive transmission. The purpose is to provide. Also,
It is a further object to provide an automatic paper feeding unit in which the drive transmission system such as the electromagnetic clutch is further simplified.

[0014]

In order to achieve the above object, the present invention provides a paper feed roller which is detachable from an image forming apparatus body and which feeds a sheet into the apparatus body by obtaining a rotational driving force. In the provided automatic paper feeding unit, an engaging member provided on the unit main body and detachably engaged with the apparatus main body, and rotatably provided on the unit main body, can be fed by the paper feed roller. An opening / closing member that is rotatable between a use position and a storage position that disables feeding, and the opening / closing member is interlocked with the device body when the opening / closing member is in the use position, And a lock member that prevents the unit body from being detached from the apparatus body even when the engagement member is disengaged.

[0015]

To attach the automatic paper feeding unit of the present invention to the main body of the image forming apparatus, the engaging member is simply engaged with the main body of the apparatus with the opening / closing member in the storage position, which is very simple.

Further, when the automatic paper feeding unit is used, when the opening / closing member is rotated from the storage position to the use position to enable feeding by the paper feeding roller, the lock member is engaged with the main body of the apparatus in conjunction with this. It will be in the state of doing. As a result, even if the engaging member is mistakenly disengaged during the paper feeding operation by the paper feeding roller, the engagement of the lock member is maintained as it is, so that the unit main body can be detached from the apparatus main body. It is prevented and problems such as gear damage are avoided. Further, during the paper feeding operation by the paper feeding roller, in addition to the engagement between the engaging member and the apparatus main body, the engagement between the locking member and the apparatus main body is performed. Fixed securely,
Stable drive transmission is obtained.

On the other hand, in order to remove the automatic paper feeding unit mounted on the image forming apparatus, first, the opening / closing member is rotated from the use position to the storage position to disable feeding by the paper feeding roller. Since the lock member is disengaged from the main body of the apparatus in conjunction with each other, it is only necessary to subsequently disengage the engagement member from the main body of the apparatus, which is very simple.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view (a part of which includes a cross section) showing a lock mechanism for locking the image forming apparatus main body M in the automatic sheet feeding unit 50 according to the embodiment of the present invention.
FIGS. 3A and 3B are a plan view and a side view, respectively, showing a drive transmission mechanism in the same embodiment, and FIG. 3 is a perspective view of a stacking base 52 in the automatic sheet feeding unit 50 of the embodiment as seen from the back side thereof. It is a figure.

The external structure of the automatic paper feeding unit 50 of the present embodiment is the same as that of the conventional compact automatic paper feeding unit 30 shown in FIG. 13, and the automatic paper feeding unit 50 of the image forming apparatus is detachable. The basic structure is also the same as that shown in FIG. 7, and the automatic paper feeding unit 50 can be attached to the paper introducing port 9 for manual paper feeding with the opening / closing member 10 removed.

As shown in FIG. 1, the automatic paper feeding unit 50 is provided with a loading platform 52 which is attached to the unit main body 51 so as to be rotatable (openable and closable) in the direction of arrow F as an opening / closing member. Indicates a use position (position shown in FIG. 1) in a substantially horizontal position in which paper can be fed by a paper feed roller (not shown) (the same as the paper feed roller 32 in FIG. 13) and a vertical position in which paper feed is disabled. The storage position (the position shown in FIG. 3) can be taken, and it functions as a paper stacking unit that can stack paper when in the horizontal position of use position. A guide member 53 that regulates the end surface of the paper is provided on the upper surface of the stacking table 52.
Is slidably provided, and an auxiliary tray 54 for supporting the paper by extending the paper stacking surface can be attached to the end of the stacking table 52.

Like the automatic paper feeding unit 30, the automatic paper feeding unit 50 has a paper feeding roller, but does not have a complicated structure such as a drive source such as a motor for driving the paper feeding roller and a control clutch. Instead, the rotational driving force of the drive gear 59 in the apparatus main body M is transmitted to the paper feed roller via a drive transmission member such as gears 55 to 58 shown in FIG.

Further, the automatic paper feeding unit 50 and the apparatus main body M
Similar to the engaging members 39 and 40 shown in FIG. 14, there are provided not-shown engaging members which can be engaged with each other at two positions, and the opening / closing member 10 (FIG. 11) also serving as a manual feed guide is installed in the device. The automatic sheet feeding unit 50 can be attached to the apparatus main body M by engaging the engaging members with the main body M removed.

Further, in this embodiment, the automatic paper feeding unit 5
Even if the engagement member is disengaged during the paper feeding operation of 0, the automatic paper feeding unit 50 does not come off from the apparatus main body M. That is, first, as shown in FIG. 1, the unit body 51 has a lock lever 61 with an arrow G.
The lock lever 61 is provided so as to be rotatable in any direction, and the lock lever 61 is engaged with an engaging hole 62 provided in the apparatus main body M (position shown by a solid line) and retracted from the engaging hole 61 (shown by a chain line). Position) and is constantly urged by a spring 63 in a direction to engage with the engagement hole 62. An arm 64 that moves integrally with the loading platform 52 as an opening / closing member is provided to be engageable with the lock lever 61. When the loading platform 52 is in the use position, the arm 64 is provided. The lock lever 6 is moved to a position (a position shown by a solid line) that allows the lock lever 61 and the engagement hole 62 to be engaged with each other, and the lock lever 6 is moved when the loading platform 52 is in the storage position.
1 is moved to a position (position indicated by a chain line) that pushes 1 in the direction of retracting from the engagement hole 62 against the biasing force of the spring 63. That is, the lock lever 6
1, the engagement hole 62, the spring 63, and the arm 64
When 2 is in the use position, it functions as a lock member that prevents detachment of the unit main body 51 from the apparatus main body M even if the above-mentioned engagement member is in the non-engaged state.

In this embodiment, the drive transmission system is connected and disconnected according to the opening / closing of the loading table 52. That is, first, as shown in FIG. 2, among the four gears 55 to 58 forming the drive transmission member, three gears 5
Although 6, 57 and 58 are rotatably supported at positions fixed to the frame 50a of the unit main body 50, the gear 55 that directly meshes with the gear 59 on the apparatus main body M side meshes with the gear 56 while surrounding the periphery thereof. It is supported by a lever 66 so as to be rotatable, and a gear 67 is supported by a spring 67.
It is always urged in the direction to engage with. Also, the loading platform 5
2, an arm (not shown) that moves integrally with its rotation is provided so as to be engageable with the lever 66.
The gear 55 and the gear 59 when the loading platform 52 is in the use position.
Move to a position that allows engagement with (the position shown in FIG. 2),
When the loading platform 52 is in the storage position, the gear 55 moves to the gear 59.
The lever 66 is moved to a position where the lever 66 is pushed away from the position. With such a configuration, the loading platform 5
The driving force can be transmitted from the apparatus main body M side through the gears 55 to 58 only when No. 2 is in the use position, and the transmission of the driving force is disconnected when the loading platform 52 is in the storage position. In addition, the arm (not shown) is the arm 6
It may be combined with 4.

Further, in this embodiment, the driving force of the drive source in the apparatus main body M is changed according to the opening / closing of the loading table 52 and the sheet feeding roller of the automatic sheet feeding unit 50 and the sheet feeding roller 2 in the apparatus main body M (see FIG. 7) and 7) can be switched and transmitted.
Such a configuration is shown in FIGS. 4 is a side view (partially including a cross section) showing an engagement mechanism of the automatic paper feeding unit 50 with the switching lever 83 on the apparatus main body M side.
5 and 6 are views showing a driving force transmission switching mechanism provided in the apparatus main body M. FIG. 5 is a state in which the driving force is transmitted to the automatic paper feeding unit 50 side, 6
Shows the state in which the driving force is transmitted to the paper feed roller 2 in the apparatus main body M.

First, as shown in FIG. 5 and FIG.
The paper feed roller 2 (see FIG. 7) for paper feed is a one-way bearer.
Is connected to the paper feed shaft 72 via a ring 71,
Only the rotation of 72 in one predetermined direction is transmitted to the paper feed roller 2.
Is done. In addition, it is slidable in the same direction as the paper feed shaft 72.
A shaft 73 is provided, and this rotary shaft 73 has the same structure as the shaft 73.
If the electromagnetic clutch 74 and clutch gear 75 are attached to the shaft,
And the whole is in the axial direction (arrow H₁, H₂Direction) move to
In addition, the compression spring 76 keeps the arrow H at all times. ₂Direction
Being energized. The clutch gear 75 has
Regardless of the driving force from the main body drive source
The dynamic gear 77 is always meshed. Electromagnetic clutch 74
Is turned on or off according to a predetermined control signal (feeding start signal).
By connecting the clutch gear 75 and the rotary shaft 73,
And release it, and drive the drive gear 77 only when turned on.
The force is transmitted to the rotating shaft 73.

Input side couplings 78 and 79 are provided at both ends of the rotary shaft 73, and one coupling 77 can be connected to an output side coupling 80 provided at one end of the paper feeding shaft 72. The other coupling 7
9 can be connected to an output side coupling 81 integrated with a gear 59 for transmitting a driving force to a gear 55 (see FIG. 2) of the automatic paper feeding unit 50. And the rotary shaft 73
Is moved in the direction of the arrow H _{1 as} shown in FIG. 5, the couplings 78, 80 are separated and the coupling 79,
On the other hand, as shown in FIG. 6, the couplings 79 and 81 are separated so that the couplings 78 and 80 are coupled when they are moved in the direction of the arrow H _{2 as} shown in FIG.
That is, the electromagnetic clutch 74, the clutch gear 75, the rotating shaft 73, the couplings 78 and 79, etc.
The first position (position shown in FIG. 5) capable of transmitting the rotational driving force to the gear 55 of the automatic sheet feeding unit 50 and the second position (position shown in FIG. 6) capable of transmitting the rotational driving force to the sheet feeding shaft 72 of the apparatus main body M. The transmission switching means is movable to and.

Further, as shown in FIGS. 4 to 6, the first lever 8 which can be engaged with the coupling 79 is attached to the main body M of the apparatus.
3a and a second lever 83b extending in a different direction
A switching lever 83 formed by integrating and is indicated by arrows J ₁ , J
It is provided to be rotatable in _two directions. Further, as shown in FIG. 4, the loading platform 52 as an opening / closing member has an arm 85 that moves integrally with the loading platform 52 (which is different from the arm 64 described above as shown in FIG. 3). Is provided so as to be engageable with the second lever 83b, and this arm 85 pushes the switching lever 83 in the direction of the arrow J ₁ when the loading platform 52 is in the use position, so as to push the first lever 83.
a moves the transmission switching means to the first position against the biasing force of the spring 76, and when the loading platform 52 is in the storage position, the switching lever 83 is retracted in the direction of arrow J ₂ to transfer the transmission switching means. Is moved to the second position by the biasing force of the spring 76. That is, the switching lever 83 and the arm 85 are provided on the loading platform 52.
Gear 55 of the automatic paper feeding unit 50 in conjunction with the opening / closing operation of
Drive transmission control means for transmitting and releasing the drive force to and from the drive transmission control means.

The attachment / detachment operation of the automatic paper feeding unit 50 and the operation at the time of paper feeding in the image forming apparatus having the above-mentioned structure will be described below. First, in order to attach the automatic paper feeding unit 50 to the apparatus main body M, the engaging member (see the engaging member 39 in FIG. 14) is attached to the apparatus main body (see FIG. 14) with the loading platform 52 in the storage position. (See the engaging member 40 of FIG. 3), which is very simple. Here, while the loading platform 52 is in the storage position, the arm 64 shown in FIG. 1 pushes the lock lever 61 so that the lock lever 61 resists the biasing force of the spring 63 and engages with the engagement hole 62 on the apparatus main body side. 2 has moved from the engageable position to the retracted position, and the lever 66 shown in FIG. 2 is also engaged with an arm (not shown) integrated with the loading table 52, so that the gear 55 causes the spring 67 to move.
Since it is moved to a position retracted from the position where it can be engaged with the gear 59 on the apparatus main body side against the urging force of the lock lever 61 and the gear 55 when the automatic paper feeding unit 50 is mounted. It is possible to perform a very smooth mounting operation.

After the automatic paper feeding unit 50 is attached to the apparatus main body M in this way, when the automatic paper feeding unit 50 is used, first, the loading table 52 is rotated from the storage position to the use position. Then, since the arm (not shown) moves in the direction away from the lever 66 shown in FIG. 2 with the rotation of the loading platform 52, as shown in FIG.
The driving force of the gear 59 can be transmitted to the gear 55 by meshing with the gear 59 on the apparatus main body side by the urging force of the gear. At the same time, the arm 85 shown in FIG. 4 rotates the switching lever 83 in the direction of the arrow J ₁ as shown in FIG. 5, so that the rotating shaft 73 and the electromagnetic clutch 7 integrated therewith.
4, the clutch gear 75 and the couplings 78 and 79 move in the direction of the arrow H ₁ against the urging force of the spring 76, and the coupling 79 is connected to the coupling 81. In this state, when the paper feed start signal is output and the electromagnetic clutch 74 is turned on, the rotational driving force of the drive gear 77 causes the clutch gear 7 to rotate.
7 is transmitted to the rotary shaft 73, and the coupling 7
The driving force of the gear 59 is transmitted to the gear 59 via the gears 55 to 58 of the automatic sheet feeding unit 50, and the sheet feeding roller is started by the automatic sheet feeding unit 50. To be done.

Here, while the loading platform 52 is in the use position, the arm 64 is locked by the lock lever 61 as shown in FIG.
Since the lock lever 61 moves in the direction of moving away from the lock lever 61, the lock lever 61 is urged by the spring 63 so that the engagement hole 6 on the apparatus main body side is
It engages with 2 and becomes a locked state. as a result,
Even if the engaging member is erroneously disengaged during the paper feeding operation by the paper feeding roller of the automatic paper feeding unit 50 (see, for example, FIG. 15).
Even if the release lever 41 shown in is pushed in the directions of the arrows E ₁ and E ₂ , the engagement between the lock lever 61 and the engagement hole 62 is maintained as it is, and the lock state remains.

Further, the automatic paper feeding unit 50 is installed in the main body M of the apparatus.
When carrying out the cassette paper feeding of the apparatus main body M with the apparatus main body M being attached to the loading main body M, the loading table 52 is rotated from the use position to the storage position.
Then, the arm (not shown) moves in a direction in which it engages with the lever 66 shown in FIG. 2 with the rotation of the loading platform 52, so that the gear 55 is separated from the gear 59 against the biasing force of the spring 67. . At the same time, the arm 85 shown in FIG. 4 moves in a direction away from the switching lever 83 as shown in FIG. 6, so that the rotating shaft 73 and the electromagnetic clutch 74 integrally formed therewith, the clutch gear 75, and the coupling. Arrows H _{2 and} 78 are caused by the urging force of the spring 76.
Moving in the direction, the coupling 79 is separated from the coupling 81 and the coupling 78 is connected to the coupling 80. In this state, when the paper feed start signal is output and the electromagnetic clutch 74 is turned on, the rotational driving force of the drive gear 77 is transmitted from the clutch gear 77 to the rotary shaft 73,
Further, it is transmitted to the paper feeding shaft 72 via the couplings 78 and 80, and the driving force of the paper feeding shaft 72 rotationally drives the paper feeding roller 2 via the one-way bearing 71 to start cassette paper feeding.

On the other hand, the automatic paper feeding unit 50 is installed in the apparatus main body M.
In order to remove from, the loading table 52 is first rotated to the storage position. Then, the connection between the gears 55 and 59 and the connection between the couplings 79 and 81 are released as described above, and the feeding by the sheet feeding roller of the automatic sheet feeding unit 50 becomes impossible.
At the same time, the arm 64 shown in FIG. 1 pushes the lock lever 61 to push the lock lever 61 and the engagement hole 6 together.
The engagement with 2 is released, that is, the locked state is released.
After that, the release lever 4 shown in FIG.
It can be easily removed only by operating 1 or the like to release the engagement of the engagement member.

Therefore, according to the present embodiment, even if the release lever 41 (FIG. 15) or the like is accidentally pushed while the automatic paper feeding unit 50 is in the paper feeding operation, the lock lever Since the engagement between 61 and the engagement hole 62 on the apparatus main body side is maintained as it is, and the detachment of the automatic paper feeding unit 50 is prevented, it is possible to reliably prevent problems such as breakage of gears that have conventionally occurred.

During the paper feeding operation by the automatic paper feeding unit 50, the engagement between the engaging member (engaging member 39 in FIG. 14) and the main body of the apparatus is performed at two places, and the lock lever 6 is used.
Since the 1 and the engaging hole 62 are also engaged, the automatic paper feeding unit 50 and the apparatus main body M are securely fixed at three points, and stable drive transmission without rattling is possible. Moreover, even though the three-point fixing is realized in this way, like the conventional automatic paper feeding unit 30, it can be attached and detached by a very simple operation as described above.

Further, the main body M of the apparatus has a control of transmitting the driving force to the sheet feeding roller 2 for feeding the cassette and the automatic sheet feeding unit 5.
Since only one electromagnetic clutch 74 and its peripheral mechanism can control the transmission of the driving force to the paper feed roller of 0, the size increase and the cost increase of the apparatus main body M can be suppressed as much as possible.

In the above embodiment, as shown in FIG. 7, an opening / closing member 10 also serving as a manual feed guide is provided at the paper feed inlet 9 for manual feed, and the automatic paper feed unit 50 is replaced with the open / close member 10. Although it is mounted, it is needless to say that the structure is not limited to this, and the structure may be simply mounted in the paper inlet.

Further, in the above-described embodiment, the stacking table 52 which functions as a paper stacking unit capable of stacking paper in the horizontal posture.
Was used as the opening / closing member, but this opening / closing member
The number of opening / closing members is not limited to two, and various members rotatably provided in a use position that enables feeding by the paper feed roller and a storage position that disables feeding can be used as the opening / closing member.

Further, the image forming apparatus shown in FIG. 7 has a structure capable of feeding cassettes in addition to the manual sheet feeding, but the image forming apparatus to which the automatic sheet feeding unit of the present invention can be mounted does not necessarily feed cassettes. However, it is sufficient that the automatic paper feeding is possible only when the automatic paper feeding unit is mounted.

[0040]

According to the present invention, since the opening / closing member is provided with the lock member that engages with the main body of the apparatus when it is in the use position, it is prevented from being accidentally detached from the main body of the apparatus during the paper feeding operation. Therefore, it is possible to reliably avoid problems such as gear damage.

Further, during the paper feeding operation by the automatic paper feeding unit, in addition to the engagement between the engaging member and the main body of the apparatus, the engagement between the lock member and the main body of the apparatus is also performed. It is securely fixed to the device body, and thus stable drive transmission without rattling is possible. Moreover, the attachment / detachment operation of the automatic paper feeding unit to / from the image forming apparatus main body is very simple.

[Brief description of drawings]

FIG. 1 is a side view (a part of which includes a cross section) showing a lock mechanism for an image forming apparatus main body M in an automatic paper feeding unit 50 according to an embodiment of the present invention.

2A and 2B are views showing a drive transmission mechanism in the embodiment, FIG. 2A is a plan view and FIG. 2B is a side view.

FIG. 3 is a perspective view of a loading platform 52 of the automatic paper feeding unit 50 as viewed from the back side thereof.

FIG. 4 is a side view (a part of which includes a cross section) showing an engagement mechanism of the automatic paper feeding unit 50 with a switching lever 83 on the apparatus main body M side.

FIG. 5 is a view showing a driving force transmission switching mechanism (a state in which the driving force is transmitted to the automatic sheet feeding unit 50 side) provided in the apparatus main body M.

6 is a diagram showing a driving force transmission switching mechanism (a state in which the driving force is transmitted to the sheet feeding roller 2 in the apparatus body M) provided in the apparatus body M. FIG.

FIG. 7 is an overall view showing an example of a conventional image forming apparatus.

FIG. 8 is an external perspective view of the conventional image forming apparatus.

FIG. 9 is an opening / closing member 10 in the conventional image forming apparatus.
It is a perspective view of.

FIG. 10 is a perspective view showing a part of a support mechanism of the opening / closing member 10.

FIG. 11 is a perspective view for explaining a detaching operation of the opening / closing member 10.

FIG. 12 is a perspective view of a conventional automatic paper feeding unit 20.

FIG. 13 is a perspective view of a conventional compact automatic paper feeding unit 30.

FIG. 14 is a perspective view for explaining a mounting operation of the automatic sheet feeding unit 30 to the apparatus main body M.

FIG. 15 is a perspective view of the apparatus main body M and an automatic sheet feeding unit 30 attached to the apparatus main body M.

FIG. 16 is a perspective view showing a state during sheet feeding by the automatic sheet feeding unit 30.

[Explanation of symbols]

 2 Paper Feeding Roller 9 Paper Inlet 50 Automatic Paper Feeding Unit 51 Unit Main Body 52 Stacking Stand 55, 56, 57, 58 Gear 59 Gear 61 Lock Lever 62 Engagement Hole 63 Spring 64 Arm 66 Lever 67 Spring 72 Paper Feeding Shaft 73 Rotation Shaft 74 Electromagnetic clutch 75 Clutch gear 76 Compression spring 77 Drive gear 78, 79, 80, 81 Coupling 83 Switching lever 85 Arm

Claims (9)

[Claims] 1. An automatic paper feeding unit, which is detachably attached to an image forming apparatus main body and has a paper feed roller for feeding a sheet into the main body of the apparatus by obtaining a rotational driving force, the automatic paper feeding unit being provided in the unit main body, An engaging member that removably engages with the apparatus main body, a use position that is rotatably provided on the unit main body, and that allows the sheet to be fed by the paper feed roller, and a storage position that disables the feeding. A rotatable opening / closing member, which is interlocked with the opening / closing member and engages with the device body when the opening / closing member is in the use position, and even if the engaging member is disengaged, from the device body And a lock member for preventing the unit body from being detached. 2. The automatic sheet feeding unit according to claim 1, wherein the sheet feeding roller receives the rotational driving force from a driving source provided in the image forming apparatus main body through a drive transmission member. 3. A drive transmission provided by the drive transmission member when the open / close member is in the use position, the drive transmission being activated when the open / close member is in the use position, and the open / close member being in the storage position. 3. The automatic sheet feeding unit according to claim 2, further comprising drive transmission control means for disabling drive transmission by the drive transmission member. 4. The attachment / detachment position to / from the image forming apparatus main body is
The automatic sheet feeding unit according to claim 3, wherein the opening / closing member is a side portion of the apparatus main body, the storage position is in a substantially vertical posture, and the use position is in a substantially horizontal posture. 5. The automatic paper feeding unit according to claim 4, wherein the opening / closing member functions as a paper stacking unit capable of stacking paper in the horizontal posture. 6. An image forming apparatus comprising an automatic paper feeding unit detachably attached to the apparatus main body, the automatic paper feeding unit having a paper feed roller for feeding a sheet toward an image forming unit inside the image forming apparatus main body by obtaining a rotational driving force. In the automatic paper feeding unit main body, and an engaging member that is detachably engaged with the apparatus main body, and a rotation member provided rotatably on the unit main body, which enables feeding by the paper feeding roller. An opening / closing member that is rotatable between a position and a storage position that disables feeding, and the opening / closing member engages with the apparatus main body when the opening / closing member is in the use position, and the engaging member And a lock member that prevents the unit main body from being detached from the apparatus main body even when is disengaged. 7. The image forming apparatus according to claim 6, wherein the sheet feeding roller receives the rotational driving force from a driving source provided in the apparatus main body via a drive transmission member. 8. The drive transmission is provided by the drive transmission member when the open / close member is in the use position, and the drive transmission is activated when the open / close member is in the use position, and the open / close member is in the storage position. 8. The image forming apparatus according to claim 7, further comprising drive transmission control means for disabling drive transmission by the drive transmission member. 9. The image forming apparatus main body comprises a sheet feeding unit that is driven by a driving force of the drive source to sequentially feed the sheets stacked and stored in a sheet storing unit and convey the sheets toward the image forming unit. The drive transmission control means includes a transmission switching means that is movable between a first position capable of transmitting the drive force of the drive source to the drive transmission member and a second position capable of transmitting the drive force to the sheet feeding means. The transmission switching means is moved to the first position when the opening / closing member is in the use position, and the transmission switching means is moved to the second position when the opening / closing member is in the storage position. Item 8. The image forming apparatus according to item 8.